WO2008018253A1 - Direction detection device - Google Patents
Direction detection device Download PDFInfo
- Publication number
- WO2008018253A1 WO2008018253A1 PCT/JP2007/063117 JP2007063117W WO2008018253A1 WO 2008018253 A1 WO2008018253 A1 WO 2008018253A1 JP 2007063117 W JP2007063117 W JP 2007063117W WO 2008018253 A1 WO2008018253 A1 WO 2008018253A1
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- WO
- WIPO (PCT)
- Prior art keywords
- directivity
- signal
- reception
- angle
- transmission
- Prior art date
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Classifications
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S3/00—Direction-finders for determining the direction from which infrasonic, sonic, ultrasonic, or electromagnetic waves, or particle emission, not having a directional significance, are being received
- G01S3/02—Direction-finders for determining the direction from which infrasonic, sonic, ultrasonic, or electromagnetic waves, or particle emission, not having a directional significance, are being received using radio waves
- G01S3/14—Systems for determining direction or deviation from predetermined direction
- G01S3/46—Systems for determining direction or deviation from predetermined direction using antennas spaced apart and measuring phase or time difference between signals therefrom, i.e. path-difference systems
- G01S3/48—Systems for determining direction or deviation from predetermined direction using antennas spaced apart and measuring phase or time difference between signals therefrom, i.e. path-difference systems the waves arriving at the antennas being continuous or intermittent and the phase difference of signals derived therefrom being measured
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- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
- G06K7/00—Methods or arrangements for sensing record carriers, e.g. for reading patterns
- G06K7/0008—General problems related to the reading of electronic memory record carriers, independent of its reading method, e.g. power transfer
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- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
- G06K7/00—Methods or arrangements for sensing record carriers, e.g. for reading patterns
- G06K7/10—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation
- G06K7/10009—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation sensing by radiation using wavelengths larger than 0.1 mm, e.g. radio-waves or microwaves
- G06K7/10019—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation sensing by radiation using wavelengths larger than 0.1 mm, e.g. radio-waves or microwaves resolving collision on the communication channels between simultaneously or concurrently interrogated record carriers.
- G06K7/10079—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation sensing by radiation using wavelengths larger than 0.1 mm, e.g. radio-waves or microwaves resolving collision on the communication channels between simultaneously or concurrently interrogated record carriers. the collision being resolved in the spatial domain, e.g. temporary shields for blindfolding the interrogator in specific directions
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q3/00—Arrangements for changing or varying the orientation or the shape of the directional pattern of the waves radiated from an antenna or antenna system
- H01Q3/26—Arrangements for changing or varying the orientation or the shape of the directional pattern of the waves radiated from an antenna or antenna system varying the relative phase or relative amplitude of energisation between two or more active radiating elements; varying the distribution of energy across a radiating aperture
- H01Q3/30—Arrangements for changing or varying the orientation or the shape of the directional pattern of the waves radiated from an antenna or antenna system varying the relative phase or relative amplitude of energisation between two or more active radiating elements; varying the distribution of energy across a radiating aperture varying the relative phase between the radiating elements of an array
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B7/00—Radio transmission systems, i.e. using radiation field
- H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
- H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
- H04B7/08—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the receiving station
- H04B7/0837—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the receiving station using pre-detection combining
- H04B7/0842—Weighted combining
- H04B7/086—Weighted combining using weights depending on external parameters, e.g. direction of arrival [DOA], predetermined weights or beamforming
Definitions
- the present invention relates to a direction detection device that performs transmission and Z or reception of a radio signal to a radio terminal and detects the direction of the radio terminal based on the radio signal, and more particularly, a multipath. It relates to technology for reducing the impact.
- An RFID (Radio Frequency Identification) system is known in which information is read out in a non-contact manner from a small-sized wireless tag (responder) in which predetermined information is stored by a predetermined wireless tag communication device (interrogator). ing.
- This RFID system can read information stored in a wireless tag by communication with the wireless tag communication device even when the wireless tag is dirty or placed at an invisible position. Therefore, practical use is expected in various fields such as product management and inspection processes.
- a direction detecting device that detects the direction of the wireless tag based on a response wave from the wireless tag.
- this is the wireless tag position detection system described in Patent Document 1.
- an interrogation wave is transmitted toward a radio tag to be detected, and a response wave returned from the radio tag power is received according to the interrogation wave, and a radio wave is transmitted to the radio tag. It is said that the direction or position of the wireless tag can be detected through communication.
- Patent Document 1 Japanese Patent Application Laid-Open No. 2006-105723
- the present invention has been made in the background of the above circumstances, and an object of the present invention is to provide a direction detection device that reduces the influence of multipath and realizes preferable direction detection. is there.
- the gist of the first invention is that a radio signal is transmitted and Z or received to a radio terminal ⁇ based on the radio signal!
- a direction detection device for detecting a direction of a terminal which is an array antenna composed of a plurality of antenna elements for transmitting a radio signal to the radio terminal and for receiving a radio signal from Z or the radio terminal
- the direction detection unit for detecting the direction of the pre-Symbol radio terminal by comparison is characterized in that it comprises.
- the gist of the second invention is that a radio signal is transmitted and Z or received to a radio terminal ⁇ based on the radio signal!
- a direction detection device for detecting a direction of a wireless terminal which is configured by a plurality of antenna elements for transmitting a wireless signal to the wireless terminal and for receiving a wireless signal of Z or its wireless terminal power.
- a plurality of antenna elements are used for transmitting a radio signal to the radio terminal and for receiving a radio signal from Z or the radio terminal.
- Array antenna a directivity control unit that controls the transmission directivity and Z or reception directivity of the array antenna by controlling the phase corresponding to each of the plurality of antenna elements, and directivity control thereof Received signals received when the transmission directivity and Z or reception directivity of the array antenna is set to a directivity direction corresponding to the first angle, and a first deviation angle shifted from the first angle by a predetermined deviation angle.
- a direction detection unit that detects the direction of the wireless terminal by comparing the received signal received in the case of the directivity direction corresponding to the angle of 2.
- the direction of the wireless terminal can be suitably detected. That is, it is possible to provide a direction detection device that reduces the influence of multipath and realizes suitable direction detection.
- a signal strength detection unit that detects a signal strength of a reception signal received by the array antenna is provided, and the direction detection unit detects the signal strength.
- the direction of the wireless terminal is detected according to the signal strength detected by the unit. In this way, the direction of the wireless terminal can be detected in a practical manner.
- the direction detection unit is received when the first angle is changed stepwise by a predetermined angle and the directivity direction corresponding to the first angle is set.
- the received signal or the signal strength thereof and the received signal or the signal strength received in the case of the directivity direction corresponding to the second angle are stored in a predetermined storage device, and the storage device
- the direction of the wireless terminal is detected by comparing the received signal stored in the signal or its signal strength. In this way, the directivity direction corresponding to an angle with less influence of multipath can be determined in a practical manner, and the direction of the wireless terminal can be suitably detected.
- the deviation angle is not less than 1Z10 and not more than 1Z5 of a predetermined angle that is a stepwise change in the first angle.
- the directivity direction of the array antenna is shifted by a sufficiently small angle, the received signal strength due to the direct wave is hardly changed, but the influence of multipath changes greatly because the path difference between the direct wave and the indirect wave changes. .
- the directivity corresponding to the angle with less influence of multipath is obtained. Sex direction can be determined, and the direction of the wireless terminal can be suitably detected.
- the deviation angle is in a range of 1 to 2 °.
- the directivity direction of the array antenna is shifted within a range of 1 to 2 °, the received signal intensity due to the direct wave is almost the same, but the path difference between the direct wave and the indirect wave changes, so multipath The impact of changes greatly. Therefore, by comparing the received signals corresponding to each directivity direction by shifting the directivity direction of the array antenna within a range of 1 to 2 °, the directivity direction corresponding to an angle with less multipath effect is obtained. And the direction of the wireless terminal can be suitably detected.
- the deviation angle is equal to or less than an allowable error angle in the direction detection of the wireless terminal.
- the influence of multipath can be reduced by comparing the received signals corresponding to the respective directivity directions by shifting the directivity direction of the array antenna within a range equal to or smaller than the allowable error angle in the direction detection.
- the directivity direction corresponding to a small angle can be determined, and the direction of the wireless terminal can be suitably detected.
- the direction detection unit first changes the transmission directivity and the array antenna of the array antenna by the directivity control unit while gradually changing the first angle by a predetermined angle.
- the received signal or the signal strength received when Z or the reception directivity is a directivity direction corresponding to each first angle is stored in the storage device, and then the first angle is determined.
- Corresponding to the second angle by shifting the array antenna's transmission directivity and Z or reception directivity by the respective first angular force deviation angle while changing the predetermined angle step by step.
- the received signal or the signal strength received in the case of the directivity direction is stored in the storage device, and the direction of the wireless terminal is determined by comparing the received signal or the signal strength stored in the storage device. It is something to detect. In this way, it is possible to determine the directivity direction corresponding to an angle with less influence of multipath in a practical manner, and it is possible to suitably detect the direction of the wireless terminal.
- the direction detection unit when the signal strength of the received signal received when the directivity direction corresponds to the first angle is equal to or less than a predetermined value, First angular force
- the directivity control corresponding to the second angle shifted by a predetermined deviation angle and the wireless signal transmission and Z or reception control are not performed. In this way, it is necessary to detect the direction of the wireless terminal by performing suitable communication due to the presence of an obstacle, etc., and omitting the control corresponding to the second angle according to the direction. Time can be shortened.
- the direction detection unit compares the detection results detected by the signal intensity detection unit for each received signal stored in the storage device, and the detection result is the maximum.
- the direction corresponding to the transmission directivity and Z or reception directivity taking a value is detected as the direction of the wireless terminal. In this way, the direction of the wireless terminal can be detected in a practical manner.
- the direction detection unit compares a detection result detected by the signal intensity detection unit for each reception signal stored in the storage device, and the detection result is the first detection result.
- the directivity direction corresponding to the angle and the directivity direction corresponding to the second angle are the direction corresponding to the transmission direction and Z or the reception directivity that are equal to or greater than a predetermined threshold. Is detected. In this way, the direction of the wireless terminal can be detected in a practical manner.
- the direction detection unit compares a detection result detected by the signal intensity detection unit for each received signal stored in the storage device, and compares the detection result with the first angle.
- the direction corresponding to the angle with the smallest difference between the detection result of the corresponding directivity direction and the detection result of the directivity direction corresponding to the second angle is detected as the direction of the wireless terminal. In this way, the direction of the wireless terminal can be detected in a practical manner.
- the direction detection unit has a directivity direction corresponding to the first angle and a directivity direction corresponding to the second angle for each reception signal stored in the storage device. For each, the detection results detected by the signal intensity detection unit are averaged, and the detection result has a maximum value in the directivity direction corresponding to the average large angle. A direction corresponding to directivity and z or reception directivity is detected as the direction of the wireless terminal. In this way, the direction of the wireless terminal can be detected in a practical manner.
- the obstacle direction detection unit that detects the direction in which the obstacle exists by comparing the received signals or the signal strengths stored in the storage device, or the direction of the obstacle is known. If there is an obstacle direction setting unit for setting the direction of the obstacle, the direction detection unit is set in the direction in which the obstacle is detected by the obstacle direction detection unit or in the obstacle direction setting unit. The direction of the wireless terminal is detected by excluding the direction. In this way, the direction of the wireless terminal can be suitably detected by avoiding the direction in which an obstacle causing multipath occurs.
- the direction detection device transmits a predetermined transmission signal toward the detection target wireless tag and returns a response signal returned from the wireless tag in response to the transmission signal.
- the wireless tag direction detection device detects a direction of the wireless tag by receiving the wireless tag. In this way, it is possible to provide a wireless tag direction detection device that reduces the influence of multipath and realizes detection of a suitable wireless tag direction.
- the direction detection unit detects a direction of the wireless tag by changing a frequency of a carrier wave of the transmission signal and comparing a reception signal received corresponding to each frequency. Is. In this way, it is possible to compare the received signals received corresponding to each directional direction at each of a plurality of carrier frequencies and use the reception result by the carrier frequency with less multipath effect.
- the direction of the wireless tag can be detected more suitably.
- each of the antenna elements is configured to transmit a radio signal to the radio terminal and to receive a radio signal from Z or the radio terminal.
- a plurality of array antennas and a direction detection unit that detects the direction of the wireless terminal by comparing received signals received as a result of transmission and Z or reception by each of the plurality of array antennas; Therefore, the direction of the wireless terminal can be suitably detected by using the reception result of the array antenna with less influence of multipaths by comparing the received signals. That is, the effect of multipath It is possible to provide a direction detection device that realizes suitable direction detection by reducing the above.
- the direction detection unit includes a directivity control unit that controls transmission directivity and Z or reception directivity of each of the plurality of sets of array antennas.
- the directivity control unit controls the transmission directivity and Z or reception directivity of each of the plurality of sets of array antennas, and the received signal is received corresponding to each transmission directivity and Z or reception directivity. Is used to detect the direction of the wireless terminal. In this way, the received signals received by the plurality of sets of array antennas corresponding to the respective transmission directivities and Z or reception directivities are compared, and the reception results obtained by the array antennas are less affected by multipath. By using it, the direction of the wireless terminal can be suitably detected.
- a signal strength detection unit that detects a signal strength of a reception signal received by the array antenna is provided, and the direction detection unit corresponds to the signal strength detected by the signal strength detection unit.
- the direction of the wireless terminal is detected. In this way, the direction of the wireless terminal can be detected in a practical manner.
- At least one of the antenna elements constituting the plurality of sets of array antennas is shared by the plurality of sets of array antennas.
- the space occupied by the plurality of array antennas can be made as small as possible, and thus the apparatus can be downsized.
- an antenna that switches a circuit so that a radio signal to the radio terminal is selectively transmitted and Z or received by any one of the plurality of array antennas. It has a selection control part. In this way, a reception signal processing circuit is provided corresponding to each array antenna by sequentially switching array antennas that transmit and Z or receive wireless signals to the wireless terminal by the antenna selection control unit.
- the configuration of the apparatus that is not necessary can be simplified.
- the plurality of array antennas have a reception signal processing circuit corresponding to each of the plurality of array antennas, and the plurality of array antennas simultaneously receive radio signals from the radio terminal. It is. In this way, the processing time of the radio signal can be shortened as much as possible, and thus the time required for detection of the radio terminal can be reduced. can do.
- the direction detection unit controls the transmission directivity and Z or reception directivity of each of the plurality of array antennas by the directivity control unit, so that each transmission directivity and Z Or, compare the detection results detected by the signal strength detection unit for the received signal received corresponding to the reception directivity, and determine the transmission direction and Z or reception directivity where the detection result takes the maximum value.
- the corresponding direction is detected as the direction of the wireless terminal. In this way, the direction of the wireless terminal can be detected in a practical manner.
- the direction detection unit controls the transmission directivity and Z or the reception directivity of each of the plurality of array antennas by the directivity control unit, so that each transmission directivity and Z
- the detection result detected by the signal strength detection unit is compared with respect to the received signal received corresponding to the reception directivity, and the detection result is equal to or greater than a predetermined threshold in any of the plurality of sets of array antennas.
- the direction corresponding to Z or reception directivity is detected as the direction of the wireless terminal. In this way, the direction of the wireless terminal can be detected in a practical manner.
- the direction detection unit controls the transmission directivity and Z or reception directivity of each of the plurality of array antennas by the directivity control unit, so that each transmission directivity and Z
- the detection results detected by the signal intensity detection unit for received signals corresponding to the reception directivity are compared, and the detection is performed at the array antenna with the least variation in the detection results among the plurality of sets of array antennas.
- the direction corresponding to the transmission directivity and Z or reception directivity where the result is the maximum value is detected as the direction of the wireless terminal. In this way, the direction of the wireless terminal can be detected in a practical manner.
- the direction detection unit controls the transmission directivity and Z or reception directivity of each of the plurality of array antennas by the directivity control unit, and corresponds to each reception directivity.
- the detection results detected by the signal strength detector for the received signal received are averaged, and the transmission directivity and Z or reception directivity at which the detection result takes the maximum value for the array antenna having the largest average.
- Direction corresponding to the direction of the wireless terminal Is detected. In this way, the direction of the wireless terminal can be detected in a practical manner.
- the array antenna also includes a plurality of linear antenna element forces arranged so as to be parallel to each other. In this way, it is possible to reduce the influence of multipath and realize suitable direction detection in the direction detection device having a practical array antenna having a plurality of linear antenna element forces.
- the distance between the linear antenna elements arranged farthest from each other is the carrier wave of the radio signal. Or less. In this way, the space occupied by the plurality of sets of array antennas can be made as small as possible, and thus the apparatus can be downsized.
- the plurality of sets of array antennas includes two linear antenna elements adjacent to each other among three linear antenna elements arranged so as to be parallel to each other.
- the radio signals can be compared by comparing the received signals corresponding to each of two sets of array antennas that are selectively composed of three linear antenna elements arranged in parallel to each other.
- the direction of the terminal can be detected suitably.
- the plurality of sets of array antennas include two linear antenna elements adjacent to each other among three linear antenna elements arranged so as to be parallel to each other.
- the direction of the wireless terminal can be preferably detected.
- the plurality of sets of array antennas are composed of two linear antenna elements adjacent to each other among four linear antenna elements arranged so as to be parallel to each other. There are 3 sets of array antennas. In this way, by comparing the received signals corresponding to each of the three sets of array antennas selectively configured from the four linear antenna elements arranged so as to be parallel to each other, Optimize the direction of the wireless terminal Can be detected.
- the plurality of sets of array antennas are selected from four linear antenna elements arranged so as to be parallel to each other. Two sets of array antennas are constructed. In this way, by comparing the received signals corresponding to each of two sets of array antennas selectively configured from four linear antenna elements arranged so as to be parallel to each other, The direction of the wireless terminal can be detected suitably.
- the direction detection unit corresponds to a predetermined relative angle range determined in advance
- the directivity control unit performs transmission directivity and Z or reception of each of the plurality of sets of array antennas.
- the directivity is controlled, and the direction of the wireless terminal is detected by comparing the reception signals received corresponding to each transmission directivity and Z or reception directivity. In this way, the time required for detection of the wireless terminal can be shortened by limiting the range of the direction detection target in advance.
- the obstacle direction detection detects the direction in which the obstacle exists by comparing the received signals received as a result of transmission and Z or reception by each of the plurality of sets of array antennas.
- an obstacle direction setting unit for setting the direction of the obstacle when the direction of the obstacle is known in advance, and the direction detection unit detects the obstacle by the obstacle direction detection unit.
- the direction of the wireless terminal is detected by excluding the direction or the direction set in the obstacle direction setting unit. In this way, the direction of the wireless terminal can be suitably detected by avoiding the direction in which the obstacle causing the multipath occurs.
- the direction detection device transmits a predetermined transmission signal toward the detection target wireless tag and returns a response signal returned from the wireless tag in response to the transmission signal.
- the wireless tag direction detection device detects a direction of the wireless tag by receiving the wireless tag. In this way, it is possible to provide a wireless tag direction detection device that reduces the influence of multipath and realizes detection of a suitable wireless tag direction.
- the direction detection unit changes the frequency of the carrier wave of the transmission signal and compares the reception signal received corresponding to each frequency to determine the direction of the wireless tag. It is to detect.
- the radio The direction of the tag can be detected suitably.
- FIG. 1 is a diagram for explaining a wireless tag communication system in which the direction detection device of the present invention is preferably used.
- FIG. 2 is a diagram for explaining the configuration of a wireless tag communication device which is a preferred embodiment of the direction detection device of the first invention.
- FIG. 3 is a diagram illustrating in detail the configuration of a transmission / reception module provided in the RFID tag communication apparatus of FIG. 2.
- FIG. 4 is a diagram illustrating a configuration of a wireless tag circuit element provided in a wireless tag that is a wireless terminal to be detected by the wireless tag communication device of FIG. 2.
- FIG. 5 is a diagram for explaining multipath that occurs when the RFID tag communication system of FIG. 1 is operated indoors.
- FIG. 6 The signal strength of the received signal received when the RFID tag communication device of FIG. 2 changes the first angle stepwise by a predetermined angle and sets the directivity direction corresponding to the first angle.
- FIG. 6 is a diagram showing a comparison between the signal strength of a received signal received in the case of a directivity direction corresponding to a second angle that is shifted from each first angle by a predetermined deviation angle.
- FIG. 7 If the signal strength of the received signal is less than or equal to the predetermined value when the directionality control corresponding to the first angle is set in the direction detection control by the RFID tag communication apparatus of FIG.
- FIG. 6 is a diagram for explaining that directivity control and radio signal transmission and Z or reception control corresponding to a second angle shifted by a predetermined deviation angle are not performed.
- FIG. 8 is a flowchart for explaining a main part of an example of tag direction detection control by the wireless tag communication device of FIG. 2.
- FIG. 9 illustrates a main part of another example of tag direction detection control by the RFID tag communication apparatus of FIG. It is a flowchart.
- FIG. 10 is a flowchart for explaining a main part of yet another example of tag direction detection control by the wireless tag communication device of FIG.
- FIG. 11 is a flowchart for explaining a main part of yet another example of tag direction detection control by the wireless tag communication device of FIG. 2.
- FIG. 12 is a flowchart for explaining a main part of still another example of tag direction detection control by the wireless tag communication device of FIG. 2.
- FIG. 13 is a flowchart for explaining a main part of yet another example of tag direction detection control by the wireless tag communication device of FIG. 2.
- FIG. 14 is a flowchart for explaining a main part of still another example of tag direction detection control by the wireless tag communication device of FIG.
- FIG. 15 is a diagram illustrating a configuration of a wireless tag communication device which is a preferred embodiment of the direction detection device of the second invention.
- FIG. 16 is a diagram illustrating a multipath that occurs when the RFID tag communication system of FIG. 1 is operated indoors.
- FIG. 19 is a flowchart for explaining a main part of an example of tag direction detection control by the wireless tag communication device of FIG.
- FIG. 20 is a flowchart for explaining a main part of another example of tag direction detection control by the wireless tag communication device of FIG.
- FIG. 21 The main part of still another example of tag direction detection control by the RFID tag communication apparatus of FIG. It is a flowchart to explain.
- 22 is a flowchart for explaining a main part of yet another example of tag direction detection control by the wireless tag communication device of FIG.
- FIG. 23 is a flowchart for explaining a main part of still another example of tag direction detection control by the wireless tag communication device of FIG. 15.
- FIG. 24 is a flowchart for explaining a main part of still another example of tag direction detection control by the wireless tag communication apparatus of FIG.
- FIG. 25 is a diagram for explaining the configuration of a wireless tag communication device which is another preferred embodiment of the direction detection device of the second invention.
- FIG. 26 is a diagram for explaining the configuration of a wireless tag communication device which is still another preferred embodiment of the direction detection device according to the second invention.
- 10 wireless tag communication system, 12, 93, 94, 96: wireless tag communication device (direction detection device), 14: wireless tag (wireless terminal), 16: array antenna, 20: carrier wave generation unit, 22: Carrier amplifier, 24: Transmitter / receiver module, 26: Antenna element, 28: Received signal synthesizer, 30: Variable amplifier, 32: Homodyne detector, 34: I3 ⁇ 4LPF, 36: 1 phase 8 0 converter, 38: 1 phase Memory part (storage device), 40: Q phase LPF, 42: Q phase AZD conversion part, 44: Q phase memory part (storage device), 4 6: Transmission circuit switching part, 48: Reception circuit switching part, 50: Transmission Data generation unit, 52: Antenna selection control unit, 54: Directivity control unit, 56: Signal strength detection unit, 58: Obstacle direction detection unit, 59: Obstacle direction setting unit, 60: Direction detection unit, 62: Transmit phase shifter, 64: Transmit amplifier, 66: Transmit / receive separation
- FIG. 1 is a diagram illustrating a radio tag communication system 10 in which the direction detection device of the present invention is preferably used.
- the RFID tag communication system 10 is a direction detection device of the first invention.
- a RFID tag communication device 12 that is one embodiment of the device and a single or plural (single in FIG. 1) wireless tags 14 that are wireless terminals to be detected by the RFID tag communication device 12, so-called RFID (Radio Frequency Identification) system, the RFID tag communication device 12 functions as an interrogator of the RFID system, and the RFID tag 14 functions as a responder. That is, when the interrogation wave F (transmission signal) is transmitted from the radio tag communication device 12 toward the radio tag 14, the radio tag 14 that has received the interrogation wave F uses a predetermined command (transmission data).
- the interrogation wave F transmission signal
- the interrogation wave F is modulated, and a response wave F (reply signal) is sent back to the RFID tag communication device 12 to communicate information between the RFID tag communication device 12 and the RFID tag 14. Is done. Through such communication, the direction or position of the wireless tag 14 relative to the wireless tag communication device 12 is detected.
- the wireless tag communication system 10 is used, for example, for management of articles in a predetermined communication area, and the wireless tag 14 is preferably attached to an article to be managed. It is integrated with the product.
- FIG. 2 is a diagram illustrating the configuration of the wireless tag communication device 12.
- the RFID tag communication apparatus 12 of the present embodiment includes a carrier generation unit 20 that generates a carrier wave of a predetermined frequency in response to a command from a direction detection unit 60 described later, and the carrier generation unit 20
- a carrier wave amplification unit 22 that amplifies the carrier wave output from the carrier wave, and a transmission signal based on the carrier wave supplied from the carrier wave amplification unit 22 is transmitted from the corresponding antenna element 26 and a reception signal received by the antenna element 26 is received.
- a plurality of transmission / reception modules 24a, 24b, 24c (3 in FIG.
- transmission / reception modules 24 2 to be processed (hereinafter simply referred to as transmission / reception modules 24 unless otherwise specified) are provided corresponding to each transmission / reception module 24a, 24b, 24c.
- Received signal combining unit 28 which is a combining unit for combining (adding) signals, variable amplifying unit 30 for amplifying the combined signal supplied from received signal combining unit 28, and supplied from variable amplifying unit 30
- a homodyne detection circuit 32 that performs homodyne detection of the composite signal
- an I-phase LPF (Low Pass Filter) 34 that passes only signals in a predetermined frequency band among the I-phase signals (in-phase components) that are also output from the homodyne detection circuit 32
- the I-phase signal that passed through the I-phase LPF34 is digitally converted.
- the I-phase memory unit 38 that stores the signal digitally converted by the I-phase AZD conversion unit 36, and the Q-phase signal (orthogonal component) output from the homodyne detection circuit 32
- a Q-phase LPF40 that passes only signals in the specified frequency band
- a Q-phase AZD converter 42 that digitally converts the Q-phase signal that has passed through the Q-phase LPF40
- a signal digitally converted by the Q-phase AZD converter 42 Q memory unit 44 for storing.
- a transmission data generation unit 50 In order to perform direction detection control for detecting the direction of the wireless tag 14, a transmission data generation unit 50, a directivity control unit 54, a signal intensity detection unit 56, an obstacle direction detection unit 58, an obstacle direction setting unit 59 and a direction detector 60 are provided.
- the antenna element 26 is, for example, a linear antenna element such as a dipole antenna, and is preferably arranged so that the plurality of linear antenna elements 26 are parallel to each other in the same plane and at equal intervals. It has been.
- the array antenna 16 that is used for both transmission and reception is constituted by the plurality of linear antenna elements 26.
- the distance between the linear antenna elements 26 arranged farthest from each other, that is, between the antenna elements 26a and 26c. Is less than the wavelength of the carrier wave generated by the carrier wave generator 20.
- FIG. 3 is a diagram for explaining the configuration of the transmission / reception module 24 in detail.
- the transmission / reception module 24 includes a transmission phase shifter 62 that is a variable phase shifter for controlling the phase of the carrier wave supplied from the carrier wave amplification unit 22, and its transmission phase shift.
- a transmission amplifier 64 that is a variable gain amplifier for modulating the output carrier wave with predetermined transmission data and outputting the transmission signal, and a signal transmission path between the transmission amplifier 64 and the antenna element 26
- a transmission signal output from the transmission amplifier 64 is supplied to the antenna element 26 via the filter 68, and is received by the antenna element 26 and supplied via the filter 68.
- Transmission / reception separating unit 66 for supplying the received signal to reception amplifier 70, and reception phase shifting unit 70, which is a variable phase shifter for controlling the phase of the received signal supplied from transmission / reception separating unit 66, , It is equipped.
- FIG. 4 is a diagram for explaining the configuration of the RFID circuit element 72 provided in the RFID tag 14. is there.
- the RFID circuit element 72 has an antenna unit 74 for transmitting and receiving signals to and from the RFID tag communication apparatus 12, and processes a signal received by the antenna unit 74.
- an IC circuit unit 76 for the purpose.
- the IC circuit unit 76 rectifies the interrogation wave F received from the RFID tag communication apparatus 12 received by the antenna unit 74, and stores the energy of the interrogation wave F rectified by the rectification unit 78.
- Power supply unit 80 a carrier wave force received by the antenna unit 74, a clock extraction unit 82 that extracts a clock signal and supplies it to the control unit 88, and a memory that functions as an information storage unit that can store a predetermined information signal Unit 84, modulation / demodulation unit 86 connected to the antenna unit 74 to modulate and demodulate signals, the RFID circuit element 72 via the rectification unit 78, the clock extraction unit 82, the modulation / demodulation unit 86, etc.
- a control unit 88 for controlling the operation of the apparatus.
- the control unit 88 performs control for storing the predetermined information in the memory unit 84 by communicating with the RFID tag communication device 12, and the interrogation wave F received by the antenna unit 74.
- basic control such as control of reflecting and returning the response wave F as the response wave F from the antenna unit 74 is executed based on the information signal stored in the memory unit 84.
- the transmission data generation unit 50 generates transmission data to be transmitted to the wireless tag 14 on the carrier wave generated by the carrier wave generation unit 20, and in each transmission / reception module 24.
- modulation is performed based on the transmission data supplied from the transmission data generating unit 50 to obtain a transmission signal, which is transmitted from the antenna element 26 through the filter 68 and the like.
- the directivity control unit 54 controls the transmission directivity and Z or reception directivity of the array antenna 16 composed of the plurality of antenna elements 26. Specifically, the transmission directivity of the array antenna 16 is controlled by controlling the phase of the transmission signal transmitted from the corresponding antenna element 26 via the transmission phase shifter 62 in each transmission / reception module 24. To do. Further, the reception directivity of the array antenna 16 is controlled by controlling the phase of the reception signal received by the corresponding antenna element 26 via the reception phase shift unit 70 in each transmission / reception module 24.
- the signal strength detection unit 56 receives a signal of a reception signal received by the array antenna 16. Detect the strength of the signal. Specifically, the I-phase signal stored in the I-phase memory unit 38 and the Q-phase signal stored in the Q-phase memory unit 44 are read, and the square root of the sum of the squares of the I-phase signal and the Q-phase signal is calculated. The signal strength of the received signal corresponding to the I-phase signal and Q-phase signal is detected by calculation.
- the obstacle direction detector 58 detects the direction in which the obstacle exists by comparing the received signals received as a result of transmission or reception by the array antenna 16. This detection is preferably performed based on the detection result of the signal intensity detection unit 56. That is, the obstacle direction detection unit 58 sets the direction in which the received signal strength is minimized or maximized as a direction in which the obstacle exists as a result of transmission or reception by the array antenna 16. To detect.
- the obstacle direction setting unit 59 sets the direction when the obstacle direction is known.
- the direction detection unit 60 is received by the directivity control unit 54 when the transmission directivity and Z or reception directivity of the array antenna 16 is set to the directivity direction corresponding to the first angle.
- the radio tag is compared by comparing a received signal received in a directivity direction corresponding to a second angle shifted from the first angle by a predetermined deviation angle (minute angle). Detect 14 directions.
- the direction detection control of the wireless tag 14 by the direction detection unit 60 will be described in detail.
- FIG. 5 is a diagram for explaining multipath that occurs when the RFID tag communication system 10 is operated in the room 90.
- the RFID tag communication system 10 when the RFID tag communication system 10 is operated in a room 90 having a wall 92 that is an obstacle (a radio wave reflector other than the RFID tag 14 to be detected) on all sides, the wall It is conceivable that a so-called multipath is generated in addition to the direct wave path due to reflection and diffraction caused by 92.
- direct waves and multipaths are indicated by solid line arrows when the transmission directivity and Z or reception directivity of the array antenna 16 are set to directivity directions corresponding to a predetermined first angle.
- the direct wave and multipath in the case of the directivity direction corresponding to the second angle shifted from the angle by a predetermined deviation angle are indicated by dashed arrows.
- the multinos and the direct wave have different phases depending on the path, so the signal of the direct wave path is strengthened by the signal of the multipath path. Or weakened.
- radio waves can reach places where direct waves do not reach.
- FIG. 6 shows signal strengths of received signals received when the first angle is changed stepwise by a predetermined angle and the directivity direction corresponding to the first angle is set.
- FIG. 6 is a diagram showing the signal strength of the received signal in comparison with the directivity direction corresponding to the second angle shifted by a predetermined deviation angle, corresponding to the first angle
- the received signal strength corresponding to the second angle is indicated by a broken line
- the received signal strength corresponding to the second angle is indicated by a broken line.
- FIG. 6 shows that the first angle is -40 with respect to a predetermined reference direction, for example, a direction indicated by a straight line passing through the antenna element 26b disposed in the center and perpendicular to the plane in which the antenna element 26 is disposed.
- the figure shows a case where the force is changed stepwise by 10 ° up to 40 °, and as such, the direction detection unit 60 preferably corresponds to the directivity corresponding to a predetermined relative angle range.
- the reception control unit 54 controls the array antenna 16 so that the transmission directivity and Z or reception directivity of the array antenna 16 are changed step by step by a predetermined angle, and is received corresponding to each transmission directivity and Z or reception directivity.
- the direction of the wireless tag 14 is detected by comparing the signals.
- the deviation angle that is, the deviation of the second angle from the first angle is preferably a predetermined angle of 1Z10 or more and 1Z5 or less, which is a step change of the first angle. In the example shown in Fig. 6, it is 1 °.
- the direction detector 60 in the RFID tag communication apparatus 12 of the present embodiment compares the received signals corresponding to the respective directivity directions by shifting the directivity direction of the array antenna 16 within the range of 1 to 2 ° in this way. By doing so, the influence of multipath is small! Determine the directivity direction corresponding to the angle.
- the deviation angle is preferably equal to or smaller than an allowable error angle in the direction detection of the radio tag 14.
- the direction detection unit 60 sets the first angle by a predetermined angle by the directivity control unit 54 (for example, 10 ° up to 40 ° force 40 ° with respect to the reference direction). If the directionality corresponding to the first angle is changed step by step, V when the received signal or its signal strength is received and the directivity direction corresponding to the second angle shifted from the first angle by a predetermined deviation angle (for example, about 1 to 2 °), V, The direction of the wireless tag 14 is detected by comparing the received signal or its signal strength.
- the directivity control unit 54 changes the transmission directivity and Z or reception directivity of the array antenna 16 while changing the first angle step by step by a predetermined angle.
- the directivity control unit 54 changes the transmission directivity and the Z or reception directivity of the array antenna 16 with respective first angular forces and second deviations shifted by a predetermined deviation angle.
- the received signal or the signal strength received when the directivity direction corresponding to the angle is stored in the storage device such as the I-phase memory unit 38 and Z or Q-phase memory unit 44, and stored in the storage device.
- Received signal or its signal Detecting the direction of the wireless tag 14 by comparing reading in degrees.
- the directivity control unit 54 changes the directivity of the array antenna 16 in steps of the predetermined angle within the predetermined angle range, thereby receiving the received signal or its signal strength. Then, the directivity control unit 54 changes the directivity of the array antenna 16 in steps of a predetermined angle within the predetermined angle range corresponding to the second angle. Control to memorize the signal strength. Further, in the control corresponding to the second angle, preferably, the result of the control corresponding to the first angle previously performed is considered, and a part of the control is performed as will be described later with reference to FIG. Is omitted.
- the direction detection control of the wireless tag 14 will be described with reference to the flowcharts of FIGS. In the control shown in the flow charts of FIGS. 8 to 14, common steps are denoted by the same reference numerals and description thereof is omitted.
- the direction detection unit 60 receives each received signal stored in the I-phase memory unit 38 and the Z-phase memory unit 44 corresponding to the first angle and the second angle, respectively. Then, the detection results detected by the signal strength detection unit 56 are compared one by one, and the direction corresponding to the transmission directivity and Z or reception directivity at which the detection result takes the maximum value is compared with the wireless tag. Detected as 14 direction.
- FIG. 8 is a flowchart for explaining a main part of the tag direction detection control of such a mode, which is repeatedly executed at a predetermined cycle.
- step (hereinafter, step is omitted) S1 an angle ⁇ indicating the directivity direction is set to ⁇ which is an initial value.
- step (hereinafter, step is omitted) S2 an angle ⁇ indicating the directivity direction is set to ⁇ which is an initial value.
- step 2 change the directivity direction to start
- the transmission phase shifter 62 and Z or the reception phase shifter 70 are set so that the angle shown is 0, and a transmission signal is transmitted toward the wireless tag 14 that is a detection target, and a response is made to the transmission signal. Then, a transmission / reception process for receiving a reply signal returned from the wireless tag 14 is performed.
- S3 the signal strength of the received signal received by the transmission / reception processing of S2 is detected, and the detection result S is stored in the I-phase memory unit 38 and the Z-phase or Q-phase memory unit 44.
- S4 it is determined whether or not the force ⁇ indicating the directivity direction is a predetermined value ⁇ . If the determination of S4 is negative, the finger d in S5
- the transmission phase shifter 62 and Z or the reception phase shifter 70 are set to transmit a transmission signal to the wireless tag 14 to be detected, and in response to the transmission signal, the wireless tag Transmission / reception processing for receiving a reply signal returned from 14 is performed.
- the signal strength of the received signal received by the transmission / reception processing in S7 is detected, and the detection result S is stored in the I-phase memory unit 38 and the Z-phase or Q-phase memory unit 44.
- S9 determines whether S9 is negative, in S10, when ⁇ 0 is added to the angle 0 indicating the directivity direction, and then the process of S7 and subsequent steps is executed again.
- S11 corresponding to the operation of the direction detection unit 60, the received signal strengths S and S stored in the I-phase memory unit 38 and Z or Q-phase memory unit 44 are read and compared, and the maximum value is obtained. After ⁇ corresponding to the received signal strength taking the following is detected as the direction of the wireless tag 14, this routine is terminated.
- S2 and S7 correspond to the operation of the directivity control unit 54
- S3 and S8 correspond to the operation of the signal intensity detection unit 56, respectively.
- the direction detection unit 60 is preferably stored in the I-phase memory unit 38 and the Z-phase or Q-phase memory unit 44 corresponding to the first angle and the second angle, respectively. For each received signal, the detection result detected by the signal intensity detection unit 56 is compared, and the detection result indicates which of the directivity direction corresponding to the first angle and the directivity direction corresponding to the second angle.
- the direction corresponding to the transmission directivity and Z or reception directivity that is equal to or greater than a predetermined threshold is detected as the direction of the wireless tag 14.
- FIG. 9 is a flowchart for explaining a main part of the tag direction detection control of such a mode, which is repeatedly executed at a predetermined cycle.
- the direction detection unit 60 is preferably stored in the I-phase memory unit 38 and the Z-phase or Q-phase memory unit 44 corresponding to the first angle and the second angle, respectively.
- the detection result detected by the signal intensity detector 56 is compared, and the detection result of the directivity direction corresponding to the first angle and the detection result of the directivity direction corresponding to the second angle are compared.
- the direction corresponding to the angle having the smallest difference from the fruit is detected as the direction of the wireless tag 14.
- FIG. 10 is a flowchart for explaining a main part of the tag direction detection control of such a mode, which is repeatedly executed at a predetermined cycle.
- the direction detection unit 60 is preferably stored in the I-phase memory unit 38 and the Z-phase or Q-phase memory unit 44 corresponding to the first angle and the second angle, respectively.
- the detection results detected by the signal intensity detection unit 56 with respect to the directivity direction corresponding to the first angle and the directivity direction corresponding to the second angle are averaged, In the directivity direction corresponding to the average large angle, the direction corresponding to the transmission directivity and Z or reception directivity in which the detection result has the maximum value is detected as the direction of the wireless tag 14.
- FIG. 11 is a flowchart for explaining the main part of the tag direction detection control of such a mode, and is repeatedly executed at a predetermined cycle. If the determination of S9 described above is affirmed in this control, V is stored in S14 corresponding to the operation of the direction detection unit 60, and stored in the I-phase memory unit 38 and Z or the Q-phase memory unit 44.
- S are read out, and the average value (arithmetic mean) is calculated for each of S 1 and S, and S ⁇ +1 ⁇ ⁇ +1
- the direction detection unit 60 is preferably based on the direction in which the obstacle is detected by the obstacle direction detection unit 58 or the direction set in the obstacle direction setting unit 59, for example.
- the direction of the wireless tag 14 is detected excluding the direction.
- FIG. 12 is a flowchart for explaining a main part of the tag direction detection control of such an aspect, and is repeatedly executed at a predetermined cycle. If the determination in S9 described above is affirmed in this control, it is stored in the I-phase memory unit 38 and the Z-phase or Q-phase memory unit 44 in S15 corresponding to the operation of the obstacle direction detection unit 58.
- the received signal strengths S and S are read, and the received signal strengths S and S are compared to detect (determine) the direction in which the obstacle exists.
- S16 corresponding to the operation of the direction detection unit 60, it corresponds to the obstacle direction detected in S15 or an angle range that is more than a predetermined angle away from the direction set in the obstacle direction setting unit 59. S and S are compared and the maximum received signal strength is
- the direction detection unit 60 preferably has a signal intensity S of a received signal that is less than or equal to a predetermined value when the directivity direction corresponds to the first angle! in case of
- FIG. 7 is a diagram for explaining such control and corresponds to the first angle.
- the signal strength s of the received signal that is received when the directivity direction is
- FIG. 5 is a flowchart for explaining a main part of the direction detection control, and is repeatedly executed at a predetermined cycle.
- the direction detection unit 60 preferably changes the frequency of the carrier wave of the transmission signal, that is, the frequency of the carrier wave generated by the carrier wave generation unit 20, and receives the signal corresponding to each frequency.
- the direction of the wireless tag 14 is detected by comparing the signals.
- FIG. 14 is a flowchart for explaining a main part of the tag direction detection control of such a mode, which is repeatedly executed in a predetermined cycle. In this control, first, in S 19, the frequency set value f of the carrier wave generated by the carrier wave generator 20 is set to f 3 ⁇ 4 and then S 1 or less.
- the process is executed. If the determination in S9 described above is affirmed, it is determined in S20 whether or not the frequency set value f of the carrier wave generated by the carrier wave generation unit 20 is f. If the determination at S20 is negative, the power at which S1 and subsequent processing is executed again after S ⁇ is added to the frequency set value f at S21. In S22 corresponding to the operation of the direction detection unit 60, the received signal strengths S and S stored in the I-phase memory unit 38 and the ⁇ or Q-phase memory unit 44 are read.
- ⁇ ⁇ +1 is extracted, and the direction of the wireless tag 14 is detected by comparing the received signal strengths S and S.
- a wireless signal to the wireless tag 14 that is a wireless terminal is transmitted.
- a directivity control unit 54 (S2 and S7) that controls the transmission directivity and Z or reception directivity of the array antenna 16, and the directivity control unit 54 control the transmission directivity and Z or reception directivity of the array antenna 16.
- the received signal received when the directivity corresponding to the first angle is set to the directivity direction corresponding to the second angle shifted by a predetermined deviation angle.
- a direction detection rod 60 (S11, S12, S13, S14, S16, S18, S22) for detecting the direction of the wireless tag 14 by comparing the received signal with the received signal. From the said reception No.
- a direction detection rod 60 (S11, S12, S13, S14, S16, S18, S22) for detecting the direction of the wireless tag 14 by comparing the received signal with the received signal. From the said reception No.
- the reception result in the directivity direction corresponding to the angle is less affected multipath by comparing, it said can and preferably detect child the direction of the wireless tag 14. That is, it is possible to provide a direction detection device that reduces the influence of multipath and realizes suitable direction detection.
- a signal strength detection unit 56 (S3 and S8) for detecting the signal strength of the received signal received by the array antenna 16 is provided, and the direction detection unit 60 is detected by the signal strength detection unit. Since the direction of the wireless tag 14 is detected according to the signal strength, the direction of the wireless tag 14 can be detected in a practical manner.
- the direction detection unit 60 receives the received signal when the first angle is changed stepwise by a predetermined angle and the directivity direction corresponding to the first angle is received, or the signal thereof
- the intensity and the received signal received in the direction of directivity corresponding to the second angle or its signal intensity are stored in the I-phase memory unit 38 and Z or Q-phase memory unit 44 that are storage devices. Since the direction of the wireless tag 14 is detected by storing and comparing the received signal stored in the storage device or its signal strength, a directivity direction corresponding to an angle with less influence of multipath is practically used. Can be determined in a specific manner
- the direction of the wireless tag 14 can be detected suitably.
- the directivity direction of the array antenna 16 is compared with the predetermined angle.
- the received signal corresponding to each directivity direction is shifted by a sufficiently small deviation angle.
- the directivity direction of the array antenna 16 is shifted within the range of 1 to 2 °, and the received signal corresponding to each directivity direction is changed.
- the directivity direction corresponding to the angle with less influence of the multipath it is possible to determine the directivity direction corresponding to the angle with less influence of the multipath, and the direction of the wireless tag 14 can be suitably detected.
- each directivity direction of the array antenna 16 is shifted within a range equal to or smaller than the allowable error angle in the direction detection.
- the directivity direction corresponding to the angle with less influence of the multipath can be determined, and the direction of the radio tag 14 can be detected suitably.
- the direction detection unit 60 first changes the first directivity stepwise by a predetermined angle step by step while the directivity control unit 54 performs transmission directivity and Z or reception directivity of the array antenna 16.
- the directivity control unit 54 Stored in the I-phase memory unit 38 and Z or Q-phase memory unit 44, and the received signal or signal strength received when the directivity is set to the directivity direction corresponding to each first angle.
- the directivity control unit 54 changes the transmission directivity and Z or reception directivity of the array antenna 16 to the respective first angular forces while changing the first angle step by step by a predetermined angle.
- the received signal or its signal strength received in the direction of directivity corresponding to the shifted second angle is stored in the I-phase memory unit 38 and Z or Q-phase memory unit 44, and the I-phase memory unit 38 And Z or Q phase memory Since the direction of the wireless tag 14 is detected by comparing the received signal or the signal strength thereof, the directivity direction corresponding to the angle can be determined in a practical manner with little multipath effect. It is possible to detect the direction of the wireless tag 14 suitably.
- the direction detection unit 60 when the signal strength of the received signal received when the directivity direction corresponds to the first angle is less than or equal to a predetermined value, Since there is no directivity control corresponding to the second angle shifted by a predetermined deviation angle and transmission and Z or reception control of the wireless signal, there is an obstacle, etc. For this reason, it is possible to shorten the time required for detecting the direction of the wireless tag 14 by performing suitable communication and omitting the control corresponding to the second angle according to the direction.
- the direction detection unit 60 detects the detection result detected by the signal intensity detection unit 56 for each received signal stored in the I-phase memory unit 38 and the Z-phase or Q-phase memory unit 44. And the direction corresponding to the transmission directivity and Z or the reception directivity at which the detection result has the maximum value is detected as the direction of the wireless tag 14, so that the wireless tag 14 can be used in a practical manner. The direction of the tag 14 can be detected.
- the direction detection unit 60 detects the detection result detected by the signal intensity detection unit 56 for each received signal stored in the I-phase memory unit 38 and the Z-phase or Q-phase memory unit 44. And the transmission directivity and Z or reception directivity in which the detection result is equal to or greater than a predetermined threshold in both the directivity direction corresponding to the first angle and the directivity direction corresponding to the second angle. Since the direction corresponding to is detected as the direction of the wireless tag 14, the direction of the wireless tag 14 can be detected in a practical manner.
- the direction detection unit 60 (S13) detects the detection result detected by the signal strength detection unit 56 for each received signal stored in the I-phase memory unit 38 and the Z-phase or Q-phase memory unit 44. And the direction corresponding to the angle with the smallest difference between the detection result of the directivity direction corresponding to the first angle and the detection result of the directivity direction corresponding to the second angle is Since the direction is detected, the direction of the wireless tag 14 can be detected in a practical manner.
- the direction detection unit 60 (S14) has a directivity direction corresponding to the first angle and each received signal stored in the I-phase memory unit 38 and the Z-phase or Q-phase memory unit 44.
- the detection results detected by the signal intensity detection unit 56 for each of the directivity directions corresponding to the second angle are averaged, and the transmission result having the maximum detection value in the directivity direction corresponding to the large average angle is transmitted. Since the direction corresponding to the directivity and Z or reception directivity is detected as the direction of the wireless tag 14, the direction of the wireless tag 14 can be detected in a practical manner.
- an obstacle direction detection unit 58 that detects the direction in which an obstacle exists by comparing the received signals or signal strengths stored in the I-phase memory unit 38 and the Z-phase or Q-phase memory unit 44. (S15), and the direction detection unit 60 (S16) excludes the direction in which the obstacle is detected by the obstacle direction detection unit 58 or the direction set in the obstacle direction setting unit 59. Since the direction of the wireless tag 14 is detected, the direction of the wireless tag 14 can be suitably detected by avoiding the direction in which an obstacle that causes multipath occurs.
- the direction detection device transmits a predetermined transmission signal toward the detection target wireless tag 14 and receives a return signal returned from the wireless tag 14 in response to the transmission signal.
- the wireless tag communication device (wireless tag direction detection device) 12 that detects the direction of the wireless tag 14, the wireless tag that realizes the preferred direction detection of the wireless tag 14 by reducing the influence of multipath.
- a communication device 12 can be provided.
- the direction detection unit 60 detects the direction of the wireless tag 14 by changing the frequency of the carrier wave of the transmission signal and comparing the received signals received corresponding to the respective frequencies. Therefore, by comparing the received signals received corresponding to the respective directivity directions in each of the plurality of carrier frequencies, and using the reception result with the carrier frequency with less influence of the multipath, the wireless tag 14 The direction can be detected more suitably.
- the directivity control unit 54, the signal intensity detection unit 56, the obstacle direction detection unit 58, the direction detection unit 60, etc. are all provided individually in the above-described embodiment.
- this first invention is not limited to this, and a control function equivalent to those of DSP (Digital Signal Processor) that executes digital signal processing including CPU, ROM, RAM, etc. It may be provided functionally. Regardless of whether the control by these control devices is digital signal processing or analog signal processing.
- DSP Digital Signal Processor
- each of the antenna elements 26 provided in the RFID tag communication apparatus 12 is a linear antenna element such as a dipole antenna, and the plurality of linear antenna elements 26 are used.
- Force that consisted of multiple sets of array antennas 16 For example, the antenna power of a flat (planar) antenna element such as a patch antenna
- the first invention can be suitably applied to a communication apparatus having such an antenna, even if it is configured.
- the first angular force is received for each first angle when the directivity direction corresponds to a single second angle shifted by a predetermined deviation angle.
- the power of detecting the direction of the wireless tag 14 by detecting the received signal and comparing the received signal corresponding to the second angle with the received signal corresponding to the first angle.
- the first angle is ⁇
- the first angular force is also shifted by a predetermined deviation angle for each first angle, such that the angle ⁇ ⁇ 1 is the second angle.
- Detecting the received signal when the directionality corresponds to the second angle, and comparing the received signal corresponding to the plurality of second angles with the received signal corresponding to the first angle The direction of the wireless tag 14 may be detected. In this way, it is possible to reduce the influence of multipath as much as possible and realize more suitable direction detection.
- the transmission / reception used for transmitting a transmission signal toward the wireless tag 14 and receiving a return signal returned from the wireless tag 14 in response to the transmission signal.
- the transmission antenna and the received signal for transmitting the transmitted signal are described above.
- the first invention is also suitably applied to an RFID tag communication apparatus that is separately provided with a receiving antenna for receiving the message.
- a predetermined transmission signal is transmitted toward the wireless tag 14 that is a communication target, and a reply signal returned from the wireless tag 14 in response to the transmission signal is received.
- the example in which the first invention is applied to the RFID tag communication device 12 that communicates information with the RFID tag 14 has been described.
- other wireless communication devices such as a mobile phone and a mobile communication device have been described.
- the first invention can also be suitably applied to direction detection of a communication terminal in a communication device.
- FIG. 15 is a diagram for explaining the configuration of a wireless tag communication device 93 according to an embodiment of the second invention.
- the RFID tag communication apparatus 93 includes the carrier generation unit 20, the carrier amplification unit 22, the transmission / reception module 24, the antenna element 26, the reception signal synthesis unit 28, and the variable amplification unit 30 described above.
- a homodyne detection circuit 32 an I-phase LPF 34, an I-phase AZD conversion unit 36, an I-phase memory unit 38, a Q-phase LPF 40, a Q-phase AZD conversion unit 42, and a Q-phase memory unit 44.
- a transmission circuit switching unit 46a that opens and closes a signal transmission circuit between the carrier wave amplification unit 22 and the transmission / reception module 24a, and a transmission circuit switching that opens and closes a signal transmission circuit between the carrier wave amplification unit 22 and the transmission / reception module 24c.
- Unit 46b (hereinafter simply referred to as a transmission circuit switching unit 46 unless otherwise distinguished from the transmission circuit switching unit 46a) and a reception circuit that opens and closes a signal transmission circuit between the transmission / reception module 24a and the reception signal synthesis unit 28.
- a circuit switching unit 48a and a reception circuit switching unit 48c that opens and closes a signal transmission circuit between the transmission / reception module 24c and the reception signal combining unit 28 (hereinafter simply referred to as a reception circuit unless otherwise distinguished from the reception circuit switching unit 48a). (Referred to as switching unit 48).
- switching unit 48 in order to perform direction detection control for detecting the direction of the wireless tag 14, a transmission data generation unit 50, a directivity control unit 54, a signal intensity detection unit 56, an obstacle that performs control according to each control unit described above A direction detection unit 58, an obstacle direction setting unit 59, and a direction detection unit 60 are provided.
- an antenna selection control unit 52 is provided in addition to these.
- the antenna selection control unit 52 transmits the transmission circuit switching unit 46, Z, or Z so that the signal is transmitted and Z or received by at least two antenna elements 26 of the plurality of antenna elements 26.
- the circuit is switched via the receiving circuit switching unit 48.
- a plurality of sets of array antennas are selectively established by the plurality of antenna elements 26. That is, regarding transmission of a transmission signal to the wireless tag 14, the array antenna 16a including the antenna elements 26a and 26b is connected to the transmission circuit by connecting the transmission circuit switching unit 46a and opening 46c. When the switching unit 46a is opened and 46c is connected, the array antenna 16b composed of the antenna elements 26b and 26c is connected to the antenna circuit by connecting the transmission circuit switching units 46a and 46c together.
- An array antenna 16c consisting of children 26a, 26b and 26c is established. Further, with respect to reception of the reply signal from the wireless tag 14, the receiving circuit switching unit 48a is connected and the array antenna 16a including the antenna elements 26a and 26b is opened by the 48c being opened, so that the receiving circuit switching unit 48a is opened.
- the array antenna 16b composed of the antenna elements 26b and 26c is connected to the antenna elements 26a, 26b, and 26c by connecting both the receiving circuit switching units 48a and 48c.
- Each of the array antennas 16c is formed.
- the antenna selection control unit 52 is one of a plurality of sets of array antennas 16a, 16b, 16c (hereinafter simply referred to as array antenna 16 unless otherwise specified).
- one antenna element 26b positioned at the center in the arrangement width direction of the antenna elements 26 is the plurality of sets.
- the directivity control unit 54 controls the transmission directivity and Z or reception directivity of each of the plurality of sets of array antennas 16. Specifically, the transmission directivity of each of the plurality of array antennas 16 is controlled by controlling the phase of the transmission signal transmitted from the corresponding antenna element 26 via the transmission phase shifter 62 in each transmission / reception module 24. To control. Further, the reception directivity of each of the plurality of sets of array antennas 16 is controlled by controlling the phase of the reception signal received by the corresponding antenna element 26 via the reception phase shift unit 70 in each transmission / reception module 24. .
- the signal strength detector 56 detects the signal strength of the received signal corresponding to each of the plurality of array antennas 16. Specifically, the I-phase signal stored in the I-phase memory unit 38 and the Q-phase signal stored in the Q-phase memory unit 44 are read, and the square root of the sum of the squares of the I-phase signal and the Q-phase signal is calculated. The signal strength of the received signal corresponding to the I-phase signal and Q-phase signal is detected by calculation.
- the obstacle direction detection unit 58 detects the direction in which the obstacle exists by comparing the received signals received as a result of transmission or reception by each of the plurality of array antennas 16. . This detection is preferably performed by the detection result of the signal intensity detection unit 56. Based on. That is, the obstacle direction detection unit 58 has the obstacle in a direction in which the signal intensity of the received signal received is minimized or maximized as a result of transmission or reception by each of the plurality of sets of array antennas 16. Detect as direction.
- the obstacle direction setting unit 59 sets the direction of the obstacle when the direction is known.
- the direction detection unit 60 detects the direction in which the wireless tag 14 exists by comparing received signals received as a result of transmission and Z or reception by the plurality of array antennas 16. That is, for each of the array antennas 16 that is selectively established by the antenna selection control unit 52, transmission and Z or reception of a wireless signal to the wireless tag 14 are performed, and reception that is received corresponding to the wireless signal is performed. The direction in which the wireless tag 14 exists is detected by comparing the signals.
- the plurality of antenna elements 26 provided in the RFID tag communication apparatus 93 of the present embodiment are preferably all linear antenna elements such as a dipole antenna, and the plurality of linear antenna elements 26 are the same. They are arranged in a plane so as to be parallel to each other and at equal intervals.
- the distance between the linear antenna elements 26 arranged farthest from each other that is, the antenna elements 26a and 26c The distance between them is equal to or less than the wavelength of the carrier wave generated by the carrier wave generator 20.
- Array antennas 16a and 16b are respectively configured. Although not particularly illustrated, in addition to the configuration of FIG. 15 described above, a transmission circuit switching unit 46b that opens and closes a signal transmission circuit between the carrier wave amplification unit 22 and the transmission / reception module 24b, and the transmission / reception module 24b and reception signal synthesis
- the array antenna 16 is composed of two linear antenna elements 26a and 26c that are arranged farthest from each other by providing a receiving circuit switching unit 48b that opens and closes a signal transmission circuit with the unit 28. I'll do it for you.
- FIG. 16 is a diagram for explaining multipath that occurs when the RFID tag communication system 10 to which the RFID tag communication apparatus 93 is applied is operated in the room 90.
- a direct wave path is caused by reflection or diffraction caused by the walls 92.
- a so-called multipath may occur.
- the direct wave and multipath by the array antenna 16a consisting of the antenna elements 26a and 26b are indicated by solid arrows
- the direct wave and multipath by the array antenna 16b consisting of the antenna elements 26b and 26c are indicated by dashed arrows, respectively.
- FIG. 17 and FIG. 18 are diagrams for explaining the difference in signal strength of the received signal when the directivity is similarly changed in the array antennas 16a and 16b.
- the signal strength of the signal is indicated by an arrow.
- the path of the multipath is also changed by changing the position of the array antenna 16 with respect to the wall 92, which is an obstacle, the transmission directivity and Z of the array antennas 16a and 16b are changed. Or, even when the reception directivity is changed in the same way, the signal strength of the received signal varies depending on the directivity.
- the direction detection unit 60 controls the transmission directivity and Z or reception directivity of each of the plurality of sets of array antennas 16 by the directivity control unit 54, and each transmission directivity and Z or The direction in which the wireless tag 14 exists is detected by comparing the detection results of the signal intensity detection unit 56 corresponding to the received signal received corresponding to the reception directivity.
- each of the plurality of sets of array antennas 16 is transmitted by the directivity control unit 54 corresponding to a predetermined relative angle range such as 30 ° to 30 ° with respect to a predetermined center direction.
- the direction of the wireless tag 14 is detected by controlling the directivity and Z or reception directivity and comparing the received signals received corresponding to each transmission directivity and Z or reception directivity.
- the direction detection unit 60 controls the transmission directivity and Z or reception directivity of each of the plurality of array antennas 16 by the directivity control unit 54, so that each transmission directivity and Compare the detection results detected by the signal strength detection unit 56 with respect to the received signal received corresponding to Z or reception directivity, and transmit directivity and Z or reception at which the detection result takes the maximum value.
- the direction corresponding to the directivity is detected as the direction of the wireless tag 14.
- FIG. 19 is a flowchart for explaining a main part of the tag direction detection control of such a mode, and is repeatedly executed at a predetermined cycle.
- the array antenna 16 specified in (2) corresponds to the array antenna 16b), and the transmission circuit switching unit 46 and the Z or reception circuit switching unit 48 are switched so that the selected array antenna 16 is configured. It is done.
- the angle ⁇ indicating the directivity direction is the initial value ⁇
- the transmission phase shift unit 62 and Z or the reception phase shift unit 70 are set according to the angle ⁇ .
- a transmission / reception process is performed in which a predetermined transmission signal is transmitted to the detection target wireless tag 14 and a reply signal returned from the wireless tag 14 in response to the transmission signal is received.
- S104 corresponding to the operation of the signal strength detection unit 56, the signal strength of the received signal received by the transmission / reception processing in S103 is detected, and the detection result S is used as the I-phase memory.
- S107 If the determination in S107 is negative, in S108, 1 is added to i, the array antenna 16 designated by i is selected, and the transmission circuit switching unit 46 and Z or the reception circuit switching unit 48 are switched. If the determination at S107 is affirmative after S102, the process at S102 and subsequent steps is executed again at S109 corresponding to the operation of the direction detection unit 60.
- the received signal strength S stored in the I-phase memory unit 38 and Z or the Q-phase memory unit 44 are all compared, and after ⁇ corresponding to S taking the maximum value is detected as the direction of the wireless tag 14, The routine is terminated.
- S101 and S108 correspond to the operation of the antenna selection control unit 52
- S102 and S106 correspond to the operation of the directivity control unit 54, respectively.
- the direction detection unit 60 preferably controls the transmission directivity and Z or reception directivity of each of the plurality of sets of array antennas 16 by the directivity control unit 54, and transmits each transmission directivity. And the detection result detected by the signal intensity detection unit 56 for the received signal corresponding to Z or reception directivity is compared, and the detection result is equal to or greater than a predetermined threshold value in any of the plurality of sets of array antennas 16. The direction corresponding to the transmission directivity and Z or the reception directivity is detected as the direction of the wireless tag 14.
- FIG. 20 is a flowchart for explaining a main part of the tag direction detection control of such an aspect, and is repeatedly executed at a predetermined cycle. If the determination in S107 described above is affirmed in this control, the data is stored in the I-phase memory unit 38 and the Z-phase memory unit 44 in S110 corresponding to the operation of the direction detection unit 60. The received signal strength S is compared and the array
- Designate antenna 16 i l ⁇ i for all angles where S is greater than or equal to a predetermined threshold A
- the direction detection unit 60 preferably controls the transmission directivity and the trapping or reception directivity of each of the plurality of sets of array antennas 16 by the directivity control unit 54, and each transmission directivity. And the detection results detected by the signal intensity detection unit 56 for received signals received corresponding to ⁇ or reception directivity, and the array having the smallest variation in the detection results among the plurality of sets of array antennas 16
- the antenna 16 detects the direction of the radio tag 14 as the direction corresponding to the transmission directivity and ⁇ or the reception directivity at which the detection result takes the maximum value.
- FIG. 21 is a flowchart for explaining a main part of the tag direction detection control of such a mode, which is repeatedly executed at a predetermined cycle.
- the direction detection unit 60 preferably controls the transmission directivity and Z or reception directivity of each of the plurality of sets of array antennas 16 by the directivity control unit 54, and each reception directivity.
- the detection results detected by the signal intensity detection unit 56 are averaged for the received signals received corresponding to the transmission directivity and Z or reception at which the detection result has the maximum value in the array antenna 16 having the largest average.
- a direction corresponding to directivity is detected as the direction of the wireless tag.
- FIG. 22 is a flowchart for explaining a main part of the tag direction detection control of such a mode, which is repeatedly executed at a predetermined cycle.
- the average value of S (arithmetic average) is calculated for each of ⁇ end, and the direction corresponding to the angle 0 at which S takes the maximum value is detected as the direction of the wireless tag 14 in the array antenna 16 having the largest average. Then, this routine is terminated.
- the direction detection unit 60 is preferably based on the direction in which the obstacle is detected by the obstacle direction detection unit 58 or the direction set in the obstacle direction setting unit 59, for example.
- the direction of the wireless tag 14 is detected excluding the direction.
- FIG. 23 is a flowchart for explaining a main part of the tag direction detection control of such an aspect, and is repeatedly executed at a predetermined cycle. If the determination in S107 described above is affirmed in this control, it is stored in the I-phase memory unit 38 and the Z-phase or Q-phase memory unit 44 in S113 corresponding to the operation of the obstacle direction detection unit 58.
- the received signal strength S is read, and the received signal strength S is compared to detect (determine) the direction in which the obstacle exists.
- S is detected in the obstacle range detected in S113 or in an angle range that is more than a predetermined angle away from the direction set in the obstacle direction setting unit 59.
- the direction corresponding to the angle 0 taking the maximum value is the wireless tag 14 After the direction is detected, this routine is terminated.
- the direction detection unit 60 preferably changes the frequency of the carrier wave of the transmission signal, that is, the frequency of the carrier wave generated by the carrier wave generation unit 20, and is received corresponding to each frequency.
- the direction of the wireless tag 14 is detected by comparing the signals.
- FIG. 24 is a flowchart for explaining a main part of the tag direction detection control in this mode, and is repeatedly executed in a predetermined cycle. In this control, first, in S115, the frequency set value f of the carrier wave generated by the carrier wave generating unit 20 is set to f 3 ⁇ 4 and then S101 and thereafter.
- a plurality of antenna elements each for transmitting a radio signal to the radio tag 14 and / or for receiving a radio signal of the power of the radio tag 14 are used.
- the direction of the wireless tag 14 can be suitably detected. That is, it is possible to provide a direction detection device that realizes suitable direction detection by reducing the influence of multipath.
- the control unit 54 controls the transmission directivity and Z or reception directivity of each of the plurality of sets of array antennas 16 and corresponds to each transmission directivity and Z or reception directivity.
- the direction of the wireless tag 14 is detected by comparing the received signals received in response to each of the transmission directivities and Z or reception directivities in each of the plurality of sets of array antennas 16. By comparing the received signals received and using the reception result by the array antenna 16 that is less affected by multipath, the direction of the wireless tag 14 can be suitably detected.
- a signal strength detection unit 56 for detecting the signal strength of the received signal received by the array antenna 16 is provided, and the direction detection unit 60 is detected by the signal strength detection unit 56. Therefore, the direction of the wireless tag 14 can be detected in a practical manner.
- the antenna elements 26 constituting the plural sets of array antennas 16 at least one antenna element 26 is shared by the plural sets of array antennas 16, so The space occupied by the _ array antenna 16 can be made as small as possible, and the apparatus can be downsized.
- the antenna selection control for switching the circuit so that the radio signal to the radio tag 14 is selectively transmitted and Z or received by any one of the array antennas 16 of the plurality of array antennas 16 Since each of the array antennas 16 (S101 and S108) is sequentially switched by the antenna selection control unit 52 to transmit and Z or receive the radio signal for the radio tag 14, the array antenna 16 Therefore, it is possible to simplify the configuration of the device that does not require the reception signal processing circuit to be provided.
- the direction detection unit 60 controls the transmission directivity and Z or reception directivity of each of the plurality of sets of array antennas 16 by the directivity control unit 54, and transmits each transmission direction.
- the received signal received corresponding to the transmission characteristics and Z or reception directivity is compared with the detection results detected by the signal intensity detection unit 56, and the detection result takes the maximum value. Since the direction corresponding to the directivity is detected as the direction of the wireless tag 14, the direction of the wireless tag 14 can be detected in a practical manner.
- the direction detection unit 60 (S110) is configured to transmit the plurality of sets of keys by the directivity control unit 54.
- the detection of the received signal received corresponding to each transmission directivity and Z or reception directivity is detected by the signal intensity detector 56 by controlling the transmission directivity and Z or reception directivity of each of the ray antennas 16. Compare the results, and detect the direction corresponding to the transmission directivity and Z or reception directivity that the detection result is equal to or greater than a predetermined threshold in any of the plurality of sets of array antennas 16 as the direction of the wireless tag 14. Therefore, the direction of the wireless tag 14 can be detected in a practical manner.
- the direction detection unit 60 controls the transmission directivity and Z or reception directivity of each of the plurality of sets of array antennas 16 by the directivity control unit 54, and transmits each transmission directivity. And the detection results detected by the signal intensity detection unit 56 for received signals received corresponding to Z or reception directivity, and the variation in the detection results of the plurality of sets of array antennas 16 is the least.
- the direction corresponding to the transmission directivity and Z or reception directivity at which the detection result of the array antenna 16 takes the maximum value is detected as the direction of the wireless tag 14, so that the wireless tag 14 is used in a practical manner. The direction of can be detected.
- the direction detection unit 60 controls the transmission directivity and Z or the reception directivity of each of the plurality of sets of array antennas 16 by the directivity control unit 54, and each reception directivity.
- the detection results detected by the signal intensity detection unit 56 are averaged with respect to the received signals received corresponding to the transmission antennas, and the transmission directivity and the maximum detection value of the array antenna 16 having the largest average are obtained. Since the direction corresponding to Z or the reception directivity is detected as the direction of the wireless tag 14, the direction of the wireless tag 14 can be detected in a practical manner.
- the array antenna 16 is composed of a plurality of linear antenna elements 26 arranged so as to be parallel to each other, the array antenna 16 is practically composed of a plurality of linear antenna elements 26. In a direction detection apparatus having a flexible array antenna 16, it is possible to reduce the influence of multipath and realize suitable direction detection.
- the distance between the linear antenna elements 26 arranged farthest from each other is determined by the carrier of the radio signal.
- the space occupied by the multiple sets of array antennas 16 is less than the wavelength. It can be made as small as possible, and thus the apparatus can be miniaturized.
- the plurality of sets of array antennas 16 are respectively composed of two linear antenna elements 26 adjacent to each other among the three linear antenna elements 26 arranged so as to be parallel to each other. 2 array antennas 16 that correspond to two sets of array antennas 16 that are selectively composed of three linear antenna elements 26 arranged so as to be parallel to each other. By comparing the received signals, the direction of the wireless tag 14 can be suitably detected.
- the plurality of sets of array antennas 16 also includes two linear antenna elements 26 adjacent to each other among the three linear antenna elements 26 arranged so as to be parallel to each other.
- the two array antennas 16 and the two array antennas 16 that are arranged at the furthest distance from each other are arranged in parallel with each other.
- the direction detection unit 60 corresponds to a predetermined relative angle range determined in advance, and the directivity control unit 54 performs transmission directivity and Z or reception of each of the plurality of sets of array antennas 16.
- the direction of the wireless tag 14 is detected by controlling the directivity and comparing the received signals received corresponding to each transmission directivity and Z or reception directivity. By limiting the target range, the time required to detect the wireless tag 14 can be shortened.
- obstacle direction detection that detects the direction in which an obstacle exists by comparing the received signals as a result of transmission and Z or reception by each of the array antennas 16 of multiple & 58 (S113), the direction detection unit 60 (S114) excludes the direction in which the obstacle is detected by the obstacle direction detection unit 58 or the direction set in the obstacle direction setting unit 59. Since the direction of the wireless tag 14 is detected, the direction of the wireless tag 14 can be suitably detected by avoiding the direction in which an obstacle causing multipath occurs.
- the direction detection device transmits a predetermined transmission toward the wireless tag 14 to be detected. Since the wireless tag direction detection device 12 detects the direction of the wireless tag 14 by receiving a reply signal transmitted from the wireless tag 14 in response to the transmission signal, It is possible to provide a wireless tag direction detection device that realizes detection of a preferable wireless tag direction by reducing the influence of a path.
- the direction detection unit 60 changes the frequency of the carrier wave of the transmission signal, and compares the reception signal received corresponding to each frequency, thereby comparing the direction of the wireless tag 14 Therefore, by comparing the received signals received corresponding to each reception directivity at each of a plurality of carrier frequencies, and using the reception result with the carrier frequency with less multipath influence, The direction of the wireless tag 14 can be detected suitably.
- FIG. 25 is a view for explaining the configuration of an RFID tag communication apparatus 94 which is another preferred embodiment of the direction detection apparatus of the second invention.
- the wireless tag communication device 94 of this embodiment includes a received signal combining unit 28a that is a combining unit that combines (adds) the received signals supplied from the transmission / reception modules 24a and 24b.
- a variable amplification unit 30a that amplifies the combined signal supplied from the received signal combining unit 28a, a homodyne detection circuit 32a that detects the combined signal supplied from the variable amplification unit 30a, and a homodyne detection circuit 32a I-phase LPF34a that passes only signals in the specified frequency band from the I-phase signal output from the I-phase AZ D converter 36a that digitally converts the I-phase signal that has passed through the I-phase LPF 34a, and its I-phase An I-phase memory unit 38a for storing the signal digitally converted by the AZD conversion unit 36a, a Q-phase LPF 40a for passing only a signal in a predetermined frequency band among the Q-phase signals output from the homodyne detection circuit 32a, Q phase LP Q-phase AZD converter 42a that digitally converts the Q-phase signal that has passed through F40a, Q-phase memory 44a that stores the signal digitally converted by the Q-phase AZD converter 42a, and the transmission
- the I-phase LPF34b that passes only signals in the specified frequency band, the I-phase AZD converter 36b that digitally converts the I-phase signal that has passed through the I-phase LPF34b, and the signal digitally converted by the I-phase AZD converter 36b I-phase memory 38b, Q-phase LPF40b that passes only signals in the specified frequency band among the Q-phase signals output from the homodyne detection circuit 32b, and Q-phase signals that have passed through the Q-phase LPF40b are digital
- a Q-phase AZ D conversion unit 42b for conversion and a Q-phase memory unit 44b for storing signals digitally converted by the Q-phase AZD conversion unit 42b are provided.
- the RFID tag communication apparatus 94 includes reception signal processing circuits such as the reception signal synthesis unit 28a, the variable amplification unit 30a, and the homodyne detection circuit 32a corresponding to the array antenna 16a.
- reception signal processing circuits such as a reception signal synthesis unit 28b, a variable amplification unit 30b, and a homodyne detection circuit 32b are provided independently, and the array antennas 16a and 16b
- the wireless tag is configured to receive as many as 14 wireless signals at the same time, so the processing time of the wireless signal can be shortened as much as possible, and thus the time required for detection of the wireless tag 14 Can be shortened
- FIG. 26 is a diagram for explaining the configuration of a wireless tag communication device 96 that is still another preferred embodiment of the direction detection device according to the second aspect of the present invention.
- the RFID tag communication apparatus 96 of the present embodiment has an antenna element 26d in addition to the antenna elements 26a, 26b, and 26c, and a transmission / reception module 24d corresponding to the antenna element 26d. It has.
- This transmission / reception module 24d has the same configuration as the transmission / reception modules 24a, 24b, 24c, etc. described above with reference to FIG. 3, and processes transmission signals based on the carrier wave supplied from the carrier wave amplification unit 22.
- the received signal transmitted from the antenna element 26d and received by the antenna element 26d is processed and supplied to the received signal combining unit 28.
- a transmission circuit switching unit 46b that opens and closes a signal transmission circuit between the carrier wave amplification unit 22 and the transmission / reception module 24b, and a transmission circuit that opens and closes a signal transmission circuit between the carrier wave amplification unit 22 and the transmission / reception module 24d.
- the reception signal synthesizer 28 is selectively selected from the transmission / reception modules 24a, 24b, 24c, 24d according to the opening / closing of the reception circuit switching units 48a, 48b, 48c, 48d. Is combined with the received signal.
- the four antenna elements 26 provided in the RFID tag communication apparatus 96 of the present embodiment are all linear antenna elements such as dipole antennas, and the plurality of linear antenna elements 26 are in the same plane. Are arranged at equal intervals so as to be parallel to each other. Of these four linear antenna elements 26, at least two antenna element 26 forces constitute the array antenna 16 for transmission and Z or reception.
- three sets of array antennas 16 are constituted by two linear antenna elements 26 adjacent to each other among the four linear antenna elements 26. That is, the antenna elements 26a and 26b constitute an array antenna 16a, the antenna elements 26b and 26c constitute an array antenna 16b, and the antenna elements 26c and 26d constitute an array antenna 16c.
- any of the three linear antenna elements 26 selected from the four linear antenna elements 26 constitutes two sets of array antennas 16. That is, the antenna elements 26a, 26b, and 26c constitute the array antenna 16d, and the antenna elements 26b, 26c, and 26d constitute the array antenna 16e.
- a plurality of sets of array antennas 16 as described above are selectively established by the antenna selection control unit 52 via the transmission circuit switching unit 46 and Z or the reception circuit switching unit 48.
- the array antenna 16 transmits and Z or receives a wireless signal to the wireless tag 14.
- the plurality of sets of array antennas 16 includes two linear antenna elements 26 arranged so as to be parallel to each other and two adjacent to each other. Since there are three sets of array antennas 16a, 16b, 16c composed of linear antenna elements 26, they are selectively composed of four linear antenna elements 26 arranged in parallel to each other. By comparing the received signals corresponding to the three sets of array antennas 16a, 16b, and 16c, the direction of the wireless tag 14 can be suitably detected.
- the plurality of sets of array antennas 16 are composed of any three linear antenna elements 26 selected from four linear antenna elements 26 arranged so as to be parallel to each other. 2 sets of array antennas 16d and 16e, so they are arranged parallel to each other.
- the direction of the wireless tag 14 can be suitably detected by comparing the received signals corresponding to each of the two sets of array antennas 16 that are selectively composed of the four linear antenna elements 26 .
- the antenna selection control unit 52 the directivity control unit 54, the signal strength detection unit 56, the obstacle direction detection unit 58, the obstacle direction setting unit 59, and the direction detection unit 60
- the second invention is not limited to this, and the same control functions as those include CPU, ROM, RAM, etc. for digital signal processing.
- a DSP Digital Signal Processor
- the control by these control devices is digital signal processing or analog signal processing.
- each of the antenna elements 26 provided in the RFID tag communication device 93 is a linear antenna element such as a dipole antenna, and the plurality of linear antenna elements 26 are used.
- Forces that consist of multiple sets of array antennas 16 For example, a flat (planar) antenna element force such as a patch antenna may be used to configure an array antenna.
- the second invention can be suitably applied to an apparatus.
- a predetermined transmission signal is transmitted to the wireless tag 14 that is a communication target, and a reply signal returned from the wireless tag 14 in response to the transmission signal is received.
- the second invention is applied to the wireless tag communication device 93 that performs information communication with the wireless tag 14.
- other wireless devices such as a mobile phone and a mobile communication device have been described.
- the second aspect of the present invention can also be suitably applied to direction detection of a communication terminal in a communication device.
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Abstract
Provided is a direction detection device capable of reducing the affect of a multi-path and realizing an appropriate direction detection. The direction detection device includes: an array antenna (16) formed by a plurality of antenna elements (26); a directivity control unit (54) for controlling a phase corresponding to each of the antennas (26) so as to control transmission and/or reception directivity of the array antennas (16); and a direction detection unit (60) for detecting a radio tag (14) by comparing a reception signal received when the directivity control unit (54) has set the transmission and/or reception directivity of the array antennas (16) to a directivity direction corresponding to a first angle, to a reception signal received when the directivity direction corresponds to a second angle obtained by shifting the first angle by a predetermined angle. Thus, by using a reception result corresponding to the angle scarcely affected by the multi-path, it is possible to appropriately detect the direction of the radio tag (14).
Description
明 細 書 Specification
方向検出装置 Direction detection device
技術分野 Technical field
[oooi] 本発明は、無線端末に対して無線信号の送信及び Z又は受信を行い、その無線 信号に基づいてその無線端末の方向を検出する方向検出装置に関し、特に、マル チパス (multipath)の影響を軽減するための技術に関する。 [oooi] The present invention relates to a direction detection device that performs transmission and Z or reception of a radio signal to a radio terminal and detects the direction of the radio terminal based on the radio signal, and more particularly, a multipath. It relates to technology for reducing the impact.
背景技術 Background art
[0002] 所定の情報が記憶された小型の無線タグ (応答器)から所定の無線タグ通信装置( 質問器)により非接触にて情報の読み出しを行う RFID (Radio Frequency Identificati on)システムが知られている。この RFIDシステムは、無線タグが汚れている場合や見 えない位置に配置されている場合であっても無線タグ通信装置との通信によりその 無線タグに記憶された情報を読み出すことが可能であることから、商品管理や検査 工程等の様々な分野にぉ 、て実用が期待されて 、る。 An RFID (Radio Frequency Identification) system is known in which information is read out in a non-contact manner from a small-sized wireless tag (responder) in which predetermined information is stored by a predetermined wireless tag communication device (interrogator). ing. This RFID system can read information stored in a wireless tag by communication with the wireless tag communication device even when the wireless tag is dirty or placed at an invisible position. Therefore, practical use is expected in various fields such as product management and inspection processes.
[0003] 斯かる無線タグ通信装置の一形態として、無線タグからの応答波に基づいてその 無線タグの方向を検出する方向検出装置としての利用が提案されている。例えば、 特許文献 1に記載された無線タグ位置検知システムがそれである。この技術によれば 、検出の対象となる無線タグに向けて質問波を送信すると共に、その質問波に応じて 上記無線タグ力 返信される応答波を受信してその無線タグとの間で無線通信を行 うことで、その無線タグの方向乃至は位置を検出することができるとされている。 As one form of such a wireless tag communication device, use as a direction detecting device that detects the direction of the wireless tag based on a response wave from the wireless tag has been proposed. For example, this is the wireless tag position detection system described in Patent Document 1. According to this technology, an interrogation wave is transmitted toward a radio tag to be detected, and a response wave returned from the radio tag power is received according to the interrogation wave, and a radio wave is transmitted to the radio tag. It is said that the direction or position of the wireless tag can be detected through communication.
[0004] 特許文献 1 :特開 2006— 105723号公報 [0004] Patent Document 1: Japanese Patent Application Laid-Open No. 2006-105723
発明の開示 Disclosure of the invention
発明が解決しょうとする課題 Problems to be solved by the invention
[0005] し力し、前述したような従来の技術にお!、て PAA (Phased Array Antenna)処理によ り無線端末の方向検出を行う場合、障害物に起因する反射や回折等により複数の電 波受信経路が生じてしまう所謂マルチパスの影響によって、検出の対象となる無線 端末に対応する方向力 の無線信号が弱くなつたり、或いは無線端末が存在しない 方向からの無線信号が強くなる等して、無線端末の方向の検出が困難になるおそれ
があった。このため、マルチパスの影響を軽減して好適な方向検出を実現する方向 検出装置の開発が求められて 、た。 [0005] However, when the direction of a wireless terminal is detected by the PAA (Phased Array Antenna) process using the conventional technology as described above, a plurality of reflections and diffractions caused by obstacles are used. Due to the effect of so-called multipath that creates a radio reception path, the radio signal of the directional force corresponding to the radio terminal to be detected becomes weak, or the radio signal from the direction where no radio terminal exists becomes strong, etc. And it may be difficult to detect the direction of the wireless terminal. was there. For this reason, there has been a demand for the development of a direction detection device that realizes suitable direction detection by reducing the influence of multipath.
[0006] 本発明は、以上の事情を背景として為されたものであり、その目的とするところは、 マルチパスの影響を軽減して好適な方向検出を実現する方向検出装置を提供する ことにある。 [0006] The present invention has been made in the background of the above circumstances, and an object of the present invention is to provide a direction detection device that reduces the influence of multipath and realizes preferable direction detection. is there.
課題を解決するための手段 Means for solving the problem
[0007] 斯かる目的を達成するために、本第 1発明の要旨とするところは、無線端末に対し て無線信号の送信及び Z又は受信を行 \その無線信号に基づ!、てその無線端末 の方向を検出する方向検出装置であって、前記無線端末への無線信号を送信する ため及び Z又はその無線端末からの無線信号を受信するための、複数のアンテナ 素子により構成されるアレイアンテナと、それら複数のアンテナ素子それぞれに対応 する位相を制御することで前記アレイアンテナの送信指向性及び Z又は受信指向性 を制御する指向性制御部と、その指向性制御部により前記アレイアンテナの送信指 向性及び Z又は受信指向性を第 1の角度に対応する指向性方向とした場合におい て受信される受信信号と、その第 1の角度力 所定の偏差角度ずらした第 2の角度に 対応する指向性方向とした場合において受信される受信信号とを、比較することで前 記無線端末の方向を検出する方向検出部とを、備えたことを特徴とするものである。 [0007] In order to achieve such an object, the gist of the first invention is that a radio signal is transmitted and Z or received to a radio terminal \ based on the radio signal! A direction detection device for detecting a direction of a terminal, which is an array antenna composed of a plurality of antenna elements for transmitting a radio signal to the radio terminal and for receiving a radio signal from Z or the radio terminal A directivity control unit that controls the transmission directivity and Z or reception directivity of the array antenna by controlling the phase corresponding to each of the plurality of antenna elements, and the directivity control unit transmits the array antenna. When the directivity and Z or reception directivity are set to the directivity direction corresponding to the first angle, the received signal and its first angular force correspond to the second angle shifted by a predetermined deviation angle. And a reception signal received in case of a directivity direction of, the direction detection unit for detecting the direction of the pre-Symbol radio terminal by comparison, is characterized in that it comprises.
[0008] また、前記目的を達成するために、本第 2発明の要旨とするところは、無線端末に 対して無線信号の送信及び Z又は受信を行 \その無線信号に基づ!、てその無線 端末の方向を検出する方向検出装置であって、前記無線端末への無線信号を送信 するため及び Z又はその無線端末力 の無線信号を受信するための、それぞれ複 数のアンテナ素子により構成される複数組のアレイアンテナと、それら複数組のァレ イアンテナそれぞれによる送信及び Z又は受信の結果、受信される受信信号を比較 することで前記無線端末の方向を検出する方向検出部とを、備えたことを特徴とする ものである。 [0008] Further, in order to achieve the above object, the gist of the second invention is that a radio signal is transmitted and Z or received to a radio terminal \ based on the radio signal! A direction detection device for detecting a direction of a wireless terminal, which is configured by a plurality of antenna elements for transmitting a wireless signal to the wireless terminal and for receiving a wireless signal of Z or its wireless terminal power. A plurality of array antennas, and a direction detection unit that detects the direction of the wireless terminal by comparing received signals received as a result of transmission and Z or reception by each of the array antennas. It is characterized by having it.
発明の効果 The invention's effect
[0009] このように、前記第 1発明によれば、前記無線端末への無線信号を送信するため及 び Z又はその無線端末からの無線信号を受信するための、複数のアンテナ素子によ
り構成されるアレイアンテナと、それら複数のアンテナ素子それぞれに対応する位相 を制御することで前記アレイアンテナの送信指向性及び Z又は受信指向性を制御す る指向性制御部と、その指向性制御部により前記アレイアンテナの送信指向性及び Z又は受信指向性を第 1の角度に対応する指向性方向とした場合において受信さ れる受信信号と、その第 1の角度から所定の偏差角度ずらした第 2の角度に対応す る指向性方向とした場合において受信される受信信号とを、比較することで前記無線 端末の方向を検出する方向検出部とを、備えたものであることから、前記受信信号を 比較してマルチパスの影響が少ない角度に対応する指向性方向における受信結果 を用いることで、前記無線端末の方向を好適に検出することができる。すなわち、マ ルチパスの影響を軽減して好適な方向検出を実現する方向検出装置を提供すること ができる。 Thus, according to the first aspect of the present invention, a plurality of antenna elements are used for transmitting a radio signal to the radio terminal and for receiving a radio signal from Z or the radio terminal. Array antenna, a directivity control unit that controls the transmission directivity and Z or reception directivity of the array antenna by controlling the phase corresponding to each of the plurality of antenna elements, and directivity control thereof Received signals received when the transmission directivity and Z or reception directivity of the array antenna is set to a directivity direction corresponding to the first angle, and a first deviation angle shifted from the first angle by a predetermined deviation angle. And a direction detection unit that detects the direction of the wireless terminal by comparing the received signal received in the case of the directivity direction corresponding to the angle of 2. By comparing the signals and using the reception result in the directivity direction corresponding to the angle with less influence of the multipath, the direction of the wireless terminal can be suitably detected. That is, it is possible to provide a direction detection device that reduces the influence of multipath and realizes suitable direction detection.
[0010] ここで、前記第 1発明において、好適には、前記アレイアンテナにより受信される受 信信号の信号強度を検出する信号強度検出部を備え、前記方向検出部は、その信 号強度検出部により検出される信号強度に応じて前記無線端末の方向を検出するも のである。このようにすれば、実用的な態様で前記無線端末の方向を検出することが できる。 [0010] Here, in the first invention, preferably, a signal strength detection unit that detects a signal strength of a reception signal received by the array antenna is provided, and the direction detection unit detects the signal strength. The direction of the wireless terminal is detected according to the signal strength detected by the unit. In this way, the direction of the wireless terminal can be detected in a practical manner.
[0011] また、好適には、前記方向検出部は、前記第 1の角度を所定角度ずつ段階的に変 ィ匕させつつその第 1の角度に対応する指向性方向とした場合において受信される受 信信号又はその信号強度と、前記第 2の角度に対応する指向性方向とした場合にお いて受信される受信信号又はその信号強度とを、所定の記憶装置に記憶し、その記 憶装置に記憶された受信信号又はその信号強度を比較することで前記無線端末の 方向を検出するものである。このようにすれば、マルチパスの影響が少ない角度に対 応する指向性方向を実用的な態様で判定することができ、前記無線端末の方向を好 適に検出することができる。 [0011] Preferably, the direction detection unit is received when the first angle is changed stepwise by a predetermined angle and the directivity direction corresponding to the first angle is set. The received signal or the signal strength thereof and the received signal or the signal strength received in the case of the directivity direction corresponding to the second angle are stored in a predetermined storage device, and the storage device The direction of the wireless terminal is detected by comparing the received signal stored in the signal or its signal strength. In this way, the directivity direction corresponding to an angle with less influence of multipath can be determined in a practical manner, and the direction of the wireless terminal can be suitably detected.
[0012] また、好適には、前記偏差角度は、前記第 1の角度の段階的な変化分である所定 角度の 1Z10以上 1Z5以下である。一般にアレイアンテナの指向性方向を十分に 小さな角度だけずらしても直接波による受信信号強度はほとんど変わらないが、直接 波と間接波との経路差が変化することからマルチパスの影響は大きく変化する。従つ
て、前記アレイアンテナの指向性方向を前記所定角度に比べて十分に小さい偏差 角度だけずらして各指向性方向に対応する受信信号を比較することで、マルチパス の影響が少ない角度に対応する指向性方向を判定することができ、前記無線端末の 方向を好適に検出することができる。 [0012] Preferably, the deviation angle is not less than 1Z10 and not more than 1Z5 of a predetermined angle that is a stepwise change in the first angle. In general, even if the directivity direction of the array antenna is shifted by a sufficiently small angle, the received signal strength due to the direct wave is hardly changed, but the influence of multipath changes greatly because the path difference between the direct wave and the indirect wave changes. . Follow By comparing the received signals corresponding to each directivity direction by shifting the directivity direction of the array antenna by a deviation angle sufficiently smaller than the predetermined angle, the directivity corresponding to the angle with less influence of multipath is obtained. Sex direction can be determined, and the direction of the wireless terminal can be suitably detected.
[0013] また、好適には、前記偏差角度は、 1乃至 2° の範囲内である。一般にアレイアンテ ナの指向性方向を 1乃至 2° の範囲内でずらしても直接波による受信信号強度はほ とんど変わらないが、直接波と間接波との経路差が変化することからマルチパスの影 響は大きく変化する。従って、前記アレイアンテナの指向性方向を 1乃至 2° の範囲 内でずらして各指向性方向に対応する受信信号を比較することで、マルチパスの影 響が少ない角度に対応する指向性方向を判定することができ、前記無線端末の方向 を好適に検出することができる。 [0013] Preferably, the deviation angle is in a range of 1 to 2 °. Generally, even if the directivity direction of the array antenna is shifted within a range of 1 to 2 °, the received signal intensity due to the direct wave is almost the same, but the path difference between the direct wave and the indirect wave changes, so multipath The impact of changes greatly. Therefore, by comparing the received signals corresponding to each directivity direction by shifting the directivity direction of the array antenna within a range of 1 to 2 °, the directivity direction corresponding to an angle with less multipath effect is obtained. And the direction of the wireless terminal can be suitably detected.
[0014] また、好適には、前記偏差角度は、前記無線端末の方向検出における許容誤差角 度以下である。このようにすれば、前記アレイアンテナの指向性方向を方向検出にお ける許容誤差角度以下の範囲内でずらして各指向性方向に対応する受信信号を比 較することで、マルチパスの影響が少ない角度に対応する指向性方向を判定するこ とができ、前記無線端末の方向を好適に検出することができる。 [0014] Preferably, the deviation angle is equal to or less than an allowable error angle in the direction detection of the wireless terminal. In this way, the influence of multipath can be reduced by comparing the received signals corresponding to the respective directivity directions by shifting the directivity direction of the array antenna within a range equal to or smaller than the allowable error angle in the direction detection. The directivity direction corresponding to a small angle can be determined, and the direction of the wireless terminal can be suitably detected.
[0015] また、好適には、前記方向検出部は、先ず、前記第 1の角度を所定角度ずつ段階 的に変化させつつ前記指向性制御部により前記アレイアンテナの送信指向性及び [0015] Preferably, the direction detection unit first changes the transmission directivity and the array antenna of the array antenna by the directivity control unit while gradually changing the first angle by a predetermined angle.
Z又は受信指向性をそれぞれの第 1の角度に対応する指向性方向とした場合にお いて受信される受信信号又はその信号強度を前記記憶装置に記憶し、次に、前記 第 1の角度を所定角度ずつ段階的に変化させつつ前記指向性制御部により前記ァ レイアンテナの送信指向性及び Z又は受信指向性をそれぞれの第 1の角度力 所 定の偏差角度ずらした第 2の角度に対応する指向性方向とした場合において受信さ れる受信信号又はその信号強度を前記記憶装置に記憶し、その記憶装置に記憶さ れた受信信号又はその信号強度を比較することで前記無線端末の方向を検出する ものである。このようにすれば、マルチパスの影響が少ない角度に対応する指向性方 向を実用的な態様で判定することができ、前記無線端末の方向を好適に検出するこ とがでさる。
[0016] また、好適には、前記方向検出部は、前記第 1の角度に対応する指向性方向とし た場合において受信される受信信号の信号強度が所定値以下だった場合には、そ の第 1の角度力 所定の偏差角度ずらした第 2の角度に対応する指向性制御及び前 記無線信号の送信及び Z又は受信制御を行わな 、ものである。このようにすれば、 障害物が存在する等の理由で好適な通信を行 、得な 、方向にっ 、て第 2の角度に 対応する制御を省くことで、前記無線端末の方向検出に要する時間を短縮すること ができる。 The received signal or the signal strength received when Z or the reception directivity is a directivity direction corresponding to each first angle is stored in the storage device, and then the first angle is determined. Corresponding to the second angle by shifting the array antenna's transmission directivity and Z or reception directivity by the respective first angular force deviation angle while changing the predetermined angle step by step. The received signal or the signal strength received in the case of the directivity direction is stored in the storage device, and the direction of the wireless terminal is determined by comparing the received signal or the signal strength stored in the storage device. It is something to detect. In this way, it is possible to determine the directivity direction corresponding to an angle with less influence of multipath in a practical manner, and it is possible to suitably detect the direction of the wireless terminal. [0016] In addition, preferably, the direction detection unit, when the signal strength of the received signal received when the directivity direction corresponds to the first angle is equal to or less than a predetermined value, First angular force The directivity control corresponding to the second angle shifted by a predetermined deviation angle and the wireless signal transmission and Z or reception control are not performed. In this way, it is necessary to detect the direction of the wireless terminal by performing suitable communication due to the presence of an obstacle, etc., and omitting the control corresponding to the second angle according to the direction. Time can be shortened.
[0017] また、好適には、前記方向検出部は、前記記憶装置に記憶された各受信信号につ いて前記信号強度検出部により検出される検出結果を一通り比較し、その検出結果 が最大値をとる送信指向性及び Z又は受信指向性に対応する方向を前記無線端末 の方向として検出するものである。このようにすれば、実用的な態様で前記無線端末 の方向を検出することができる。 [0017] Preferably, the direction detection unit compares the detection results detected by the signal intensity detection unit for each received signal stored in the storage device, and the detection result is the maximum. The direction corresponding to the transmission directivity and Z or reception directivity taking a value is detected as the direction of the wireless terminal. In this way, the direction of the wireless terminal can be detected in a practical manner.
[0018] また、好適には、前記方向検出部は、前記記憶装置に記憶された各受信信号につ いて前記信号強度検出部により検出される検出結果を比較し、その検出結果が前記 第 1の角度に対応する指向性方向及び第 2の角度に対応する指向性方向の何れに おいても所定の閾値以上となる送信指向性及び Z又は受信指向性に対応する方向 を前記無線端末の方向として検出するものである。このようにすれば、実用的な態様 で前記無線端末の方向を検出することができる。 [0018] Preferably, the direction detection unit compares a detection result detected by the signal intensity detection unit for each reception signal stored in the storage device, and the detection result is the first detection result. The directivity direction corresponding to the angle and the directivity direction corresponding to the second angle are the direction corresponding to the transmission direction and Z or the reception directivity that are equal to or greater than a predetermined threshold. Is detected. In this way, the direction of the wireless terminal can be detected in a practical manner.
[0019] また、好適には、前記方向検出部は、前記記憶装置に記憶された各受信信号につ いて前記信号強度検出部により検出される検出結果を比較し、前記第 1の角度に対 応する指向性方向の検出結果と第 2の角度に対応する指向性方向の検出結果との 差が最も小さい角度に対応する方向を前記無線端末の方向として検出するものであ る。このようにすれば、実用的な態様で前記無線端末の方向を検出することができる [0019] Preferably, the direction detection unit compares a detection result detected by the signal intensity detection unit for each received signal stored in the storage device, and compares the detection result with the first angle. The direction corresponding to the angle with the smallest difference between the detection result of the corresponding directivity direction and the detection result of the directivity direction corresponding to the second angle is detected as the direction of the wireless terminal. In this way, the direction of the wireless terminal can be detected in a practical manner.
[0020] また、好適には、前記方向検出部は、前記記憶装置に記憶された各受信信号につ いて前記第 1の角度に対応する指向性方向及び第 2の角度に対応する指向性方向 それぞれに関して前記信号強度検出部により検出される検出結果を平均し、その平 均の大きな角度に対応する指向性方向において前記検出結果が最大値をとる送信
指向性及び z又は受信指向性に対応する方向を前記無線端末の方向として検出す るものである。このようにすれば、実用的な態様で前記無線端末の方向を検出するこ とがでさる。 [0020] Preferably, the direction detection unit has a directivity direction corresponding to the first angle and a directivity direction corresponding to the second angle for each reception signal stored in the storage device. For each, the detection results detected by the signal intensity detection unit are averaged, and the detection result has a maximum value in the directivity direction corresponding to the average large angle. A direction corresponding to directivity and z or reception directivity is detected as the direction of the wireless terminal. In this way, the direction of the wireless terminal can be detected in a practical manner.
[0021] また、好適には、前記記憶装置に記憶された各受信信号又は信号強度を比較する ことで障害物の存在する方向を検出する障害物方向検出部、又は障害物の方向が 既知である場合その障害物の方向を設定する障害物方向設定部を備え、前記方向 検出部は、その障害物方向検出部により障害物が検出された方向、又は前記障害 物方向設定部に設定された方向を除外して前記無線端末の方向を検出するもので ある。このようにすれば、マルチパス発生の原因となる障害物が存在する方向を避け ることで、前記無線端末の方向を好適に検出することができる。 [0021] Preferably, the obstacle direction detection unit that detects the direction in which the obstacle exists by comparing the received signals or the signal strengths stored in the storage device, or the direction of the obstacle is known. If there is an obstacle direction setting unit for setting the direction of the obstacle, the direction detection unit is set in the direction in which the obstacle is detected by the obstacle direction detection unit or in the obstacle direction setting unit. The direction of the wireless terminal is detected by excluding the direction. In this way, the direction of the wireless terminal can be suitably detected by avoiding the direction in which an obstacle causing multipath occurs.
[0022] また、好適には、前記方向検出装置は、検出対象である無線タグに向けて所定の 送信信号を送信すると共に、その送信信号に応答して前記無線タグから返信される 返信信号を受信することで前記無線タグの方向を検出する無線タグ方向検出装置で ある。このようにすれば、マルチパスの影響を軽減して好適な無線タグ方向の検出を 実現する無線タグ方向検出装置を提供することができる。 [0022] Preferably, the direction detection device transmits a predetermined transmission signal toward the detection target wireless tag and returns a response signal returned from the wireless tag in response to the transmission signal. The wireless tag direction detection device detects a direction of the wireless tag by receiving the wireless tag. In this way, it is possible to provide a wireless tag direction detection device that reduces the influence of multipath and realizes detection of a suitable wireless tag direction.
[0023] また、好適には、前記方向検出部は、前記送信信号の搬送波の周波数を変化させ 、各周波数に対応して受信される受信信号を比較することで前記無線タグの方向を 検出するものである。このようにすれば、複数の搬送波周波数それぞれにおける各指 向性方向に対応して受信される受信信号を比較してマルチパスの影響が少な 、搬 送波周波数による受信結果を用 、ることで、前記無線タグの方向を更に好適に検出 することができる。 [0023] Preferably, the direction detection unit detects a direction of the wireless tag by changing a frequency of a carrier wave of the transmission signal and comparing a reception signal received corresponding to each frequency. Is. In this way, it is possible to compare the received signals received corresponding to each directional direction at each of a plurality of carrier frequencies and use the reception result by the carrier frequency with less multipath effect. The direction of the wireless tag can be detected more suitably.
[0024] また、前記第 2発明によれば、前記無線端末への無線信号を送信するため及び Z 又はその無線端末からの無線信号を受信するための、それぞれ複数のアンテナ素 子により構成される複数組のアレイアンテナと、それら複数組のアレイアンテナそれぞ れによる送信及び Z又は受信の結果、受信される受信信号を比較することで前記無 線端末の方向を検出する方向検出部とを、備えたものであることから、前記受信信号 を比較してマルチパスの影響が少な 、アレイアンテナによる受信結果を用いることで 、前記無線端末の方向を好適に検出することができる。すなわち、マルチパスの影響
を軽減して好適な方向検出を実現する方向検出装置を提供することができる。 [0024] According to the second invention, each of the antenna elements is configured to transmit a radio signal to the radio terminal and to receive a radio signal from Z or the radio terminal. A plurality of array antennas and a direction detection unit that detects the direction of the wireless terminal by comparing received signals received as a result of transmission and Z or reception by each of the plurality of array antennas; Therefore, the direction of the wireless terminal can be suitably detected by using the reception result of the array antenna with less influence of multipaths by comparing the received signals. That is, the effect of multipath It is possible to provide a direction detection device that realizes suitable direction detection by reducing the above.
[0025] ここで、前記第 2発明にお 、て、好適には、前記複数組のアレイアンテナそれぞれ の送信指向性及び Z又は受信指向性を制御する指向性制御部を備え、前記方向 検出部は、その指向性制御部により前記複数組のアレイアンテナそれぞれの送信指 向性及び Z又は受信指向性を制御し、各送信指向性及び Z又は受信指向性に対 応して受信される受信信号を比較することで前記無線端末の方向を検出するもので ある。このようにすれば、前記複数組のアレイアンテナそれぞれにおける各送信指向 性及び Z又は受信指向性に対応して受信される受信信号を比較してマルチパスの 影響が少な 、アレイアンテナによる受信結果を用いることで、前記無線端末の方向を 好適に検出することができる。 [0025] Here, in the second invention, preferably, the direction detection unit includes a directivity control unit that controls transmission directivity and Z or reception directivity of each of the plurality of sets of array antennas. The directivity control unit controls the transmission directivity and Z or reception directivity of each of the plurality of sets of array antennas, and the received signal is received corresponding to each transmission directivity and Z or reception directivity. Is used to detect the direction of the wireless terminal. In this way, the received signals received by the plurality of sets of array antennas corresponding to the respective transmission directivities and Z or reception directivities are compared, and the reception results obtained by the array antennas are less affected by multipath. By using it, the direction of the wireless terminal can be suitably detected.
[0026] また、好適には、前記アレイアンテナにより受信される受信信号の信号強度を検出 する信号強度検出部を備え、前記方向検出部は、その信号強度検出部により検出さ れる信号強度に応じて前記無線端末の方向を検出するものである。このようにすれ ば、実用的な態様で前記無線端末の方向を検出することができる。 [0026] In addition, preferably, a signal strength detection unit that detects a signal strength of a reception signal received by the array antenna is provided, and the direction detection unit corresponds to the signal strength detected by the signal strength detection unit. The direction of the wireless terminal is detected. In this way, the direction of the wireless terminal can be detected in a practical manner.
[0027] また、好適には、前記複数組のアレイアンテナを構成するアンテナ素子のうち、少 なくとも 1つのアンテナ素子はそれら複数組のアレイアンテナに共用されるものである 。このようにすれば、前記複数 のアレイアンテナが占める空間を可及的に小さくす ることができ、延いては装置を小型化できる。 [0027] Preferably, at least one of the antenna elements constituting the plurality of sets of array antennas is shared by the plurality of sets of array antennas. In this way, the space occupied by the plurality of array antennas can be made as small as possible, and thus the apparatus can be downsized.
[0028] また、好適には、前記複数組のアレイアンテナのうち何れか 1組のアレイアンテナに より選択的に前記無線端末に対する無線信号が送信及び Z又は受信されるように回 路を切り替えるアンテナ選択制御部を有するものである。このようにすれば、そのアン テナ選択制御部により前記無線端末に対する無線信号を送信及び Z又は受信する アレイアンテナを順次切り替えてゆくことで、各アレイアンテナに対応して受信信号処 理回路を設ける必要がなぐ装置の構成を簡単なものとすることができる。 [0028] Also, preferably, an antenna that switches a circuit so that a radio signal to the radio terminal is selectively transmitted and Z or received by any one of the plurality of array antennas. It has a selection control part. In this way, a reception signal processing circuit is provided corresponding to each array antenna by sequentially switching array antennas that transmit and Z or receive wireless signals to the wireless terminal by the antenna selection control unit. The configuration of the apparatus that is not necessary can be simplified.
[0029] また、好適には、前記複数組のアレイアンテナそれぞれに対応して受信信号処理 回路を有するものであり、それら複数 のアレイアンテナは、前記無線端末からの無 線信号を同時に受信するものである。このようにすれば、前記無線信号の処理時間 を可及的に短縮することができ、延いては前記無線端末の検出に要する時間を短縮
することができる。 [0029] Preferably, the plurality of array antennas have a reception signal processing circuit corresponding to each of the plurality of array antennas, and the plurality of array antennas simultaneously receive radio signals from the radio terminal. It is. In this way, the processing time of the radio signal can be shortened as much as possible, and thus the time required for detection of the radio terminal can be reduced. can do.
[0030] また、好適には、前記方向検出部は、前記指向性制御部により前記複数組のァレ イアンテナそれぞれの送信指向性及び Z又は受信指向性を制御し、各送信指向性 及び Z又は受信指向性に対応して受信される受信信号について前記信号強度検出 部により検出される検出結果を一通り比較し、その検出結果が最大値をとる送信指 向性及び Z又は受信指向性に対応する方向を前記無線端末の方向として検出する ものである。このようにすれば、実用的な態様で前記無線端末の方向を検出すること ができる。 [0030] Preferably, the direction detection unit controls the transmission directivity and Z or reception directivity of each of the plurality of array antennas by the directivity control unit, so that each transmission directivity and Z Or, compare the detection results detected by the signal strength detection unit for the received signal received corresponding to the reception directivity, and determine the transmission direction and Z or reception directivity where the detection result takes the maximum value. The corresponding direction is detected as the direction of the wireless terminal. In this way, the direction of the wireless terminal can be detected in a practical manner.
[0031] また、好適には、前記方向検出部は、前記指向性制御部により前記複数組のァレ イアンテナそれぞれの送信指向性及び Z又は受信指向性を制御し、各送信指向性 及び Z又は受信指向性に対応して受信される受信信号について前記信号強度検出 部により検出される検出結果を比較し、その検出結果が前記複数組のアレイアンテ ナ何れにおいても所定の閾値以上となる送信指向性及び Z又は受信指向性に対応 する方向を前記無線端末の方向として検出するものである。このようにすれば、実用 的な態様で前記無線端末の方向を検出することができる。 [0031] Preferably, the direction detection unit controls the transmission directivity and Z or the reception directivity of each of the plurality of array antennas by the directivity control unit, so that each transmission directivity and Z Alternatively, the detection result detected by the signal strength detection unit is compared with respect to the received signal received corresponding to the reception directivity, and the detection result is equal to or greater than a predetermined threshold in any of the plurality of sets of array antennas. And the direction corresponding to Z or reception directivity is detected as the direction of the wireless terminal. In this way, the direction of the wireless terminal can be detected in a practical manner.
[0032] また、好適には、前記方向検出部は、前記指向性制御部により前記複数組のァレ イアンテナそれぞれの送信指向性及び Z又は受信指向性を制御し、各送信指向性 及び Z又は受信指向性に対応して受信される受信信号について前記信号強度検出 部により検出される検出結果を比較し、前記複数組のアレイアンテナのうちその検出 結果の変動が最も少ないアレイアンテナにおいてその検出結果が最大値をとる送信 指向性及び Z又は受信指向性に対応する方向を前記無線端末の方向として検出す るものである。このようにすれば、実用的な態様で前記無線端末の方向を検出するこ とがでさる。 [0032] Preferably, the direction detection unit controls the transmission directivity and Z or reception directivity of each of the plurality of array antennas by the directivity control unit, so that each transmission directivity and Z Alternatively, the detection results detected by the signal intensity detection unit for received signals corresponding to the reception directivity are compared, and the detection is performed at the array antenna with the least variation in the detection results among the plurality of sets of array antennas. The direction corresponding to the transmission directivity and Z or reception directivity where the result is the maximum value is detected as the direction of the wireless terminal. In this way, the direction of the wireless terminal can be detected in a practical manner.
[0033] また、好適には、前記方向検出部は、前記指向性制御部により前記複数組のァレ イアンテナそれぞれの送信指向性及び Z又は受信指向性を制御し、各受信指向性 に対応して受信される受信信号について前記信号強度検出部により検出される検出 結果を平均し、その平均の最も大きなアレイアンテナにお 、て前記検出結果が最大 値をとる送信指向性及び Z又は受信指向性に対応する方向を前記無線端末の方向
として検出するものである。このようにすれば、実用的な態様で前記無線端末の方向 を検出することができる。 [0033] Preferably, the direction detection unit controls the transmission directivity and Z or reception directivity of each of the plurality of array antennas by the directivity control unit, and corresponds to each reception directivity. The detection results detected by the signal strength detector for the received signal received are averaged, and the transmission directivity and Z or reception directivity at which the detection result takes the maximum value for the array antenna having the largest average. Direction corresponding to the direction of the wireless terminal Is detected. In this way, the direction of the wireless terminal can be detected in a practical manner.
[0034] また、好適には、前記アレイアンテナは、互いに平行を成すように配設された複数 本の直線状アンテナ素子力も構成されるものである。このようにすれば、複数本の直 線状アンテナ素子力 成る実用的なアレイアンテナを有する方向検出装置において マルチパスの影響を軽減して好適な方向検出を実現することができる。 [0034] Preferably, the array antenna also includes a plurality of linear antenna element forces arranged so as to be parallel to each other. In this way, it is possible to reduce the influence of multipath and realize suitable direction detection in the direction detection device having a practical array antenna having a plurality of linear antenna element forces.
[0035] また、好適には、前記アレイアンテナを構成する複数本の直線状アンテナ素子のう ち、相互に最も離れて配設された直線状アンテナ素子相互間の距離は、前記無線 信号の搬送波の波長以下である。このようにすれば、前記複数組のアレイアンテナが 占める空間を可及的に小さくすることができ、延いては装置を小型化できる。 [0035] Preferably, among the plurality of linear antenna elements constituting the array antenna, the distance between the linear antenna elements arranged farthest from each other is the carrier wave of the radio signal. Or less. In this way, the space occupied by the plurality of sets of array antennas can be made as small as possible, and thus the apparatus can be downsized.
[0036] また、好適には、前記複数組のアレイアンテナは、互いに平行を成すように配設さ れた 3本の直線状アンテナ素子のうち相互に隣接する 2本ずつの直線状アンテナ素 子力もそれぞれ構成される 2組のアレイアンテナである。このようにすれば、互いに平 行を成すように配設された 3本の直線状アンテナ素子から選択的に構成される 2組の アレイアンテナそれぞれに対応する受信信号を比較することで、前記無線端末の方 向を好適に検出することができる。 [0036] Preferably, the plurality of sets of array antennas includes two linear antenna elements adjacent to each other among three linear antenna elements arranged so as to be parallel to each other. There are two sets of array antennas, each of which consists of forces. In this way, the radio signals can be compared by comparing the received signals corresponding to each of two sets of array antennas that are selectively composed of three linear antenna elements arranged in parallel to each other. The direction of the terminal can be detected suitably.
[0037] また、好適には、前記複数組のアレイアンテナは、互いに平行を成すように配設さ れた 3本の直線状アンテナ素子のうち相互に隣接する 2本ずつの直線状アンテナ素 子力もそれぞれ構成される 2組のアレイアンテナ、及び相互に最も離れて配設された 2本の直線状アンテナ素子力も構成される 1組のアレイアンテナである。このようにす れば、互 、に平行を成すように配設された 3本の直線状アンテナ素子力 選択的に 構成される 3組のアレイアンテナそれぞれに対応する受信信号を比較することで、前 記無線端末の方向を好適に検出することができる。 [0037] Preferably, the plurality of sets of array antennas include two linear antenna elements adjacent to each other among three linear antenna elements arranged so as to be parallel to each other. There are two sets of array antennas, each of which is also configured with force, and one set of array antennas, which is also configured with the force of two linear antenna elements arranged farthest from each other. In this way, by comparing the received signals corresponding to each of the three sets of array antennas that are selectively configured with three linear antenna element forces arranged so as to be parallel to each other, The direction of the wireless terminal can be preferably detected.
[0038] また、好適には、前記複数組のアレイアンテナは、互いに平行を成すように配設さ れた 4本の直線状アンテナ素子のうち相互に隣接する 2本の直線状アンテナ素子か ら構成される 3組のアレイアンテナである。このようにすれば、互いに平行を成すよう に配設された 4本の直線状アンテナ素子カゝら選択的に構成される 3組のアレイアンテ ナそれぞれに対応する受信信号を比較することで、前記無線端末の方向を好適に
検出することができる。 [0038] Preferably, the plurality of sets of array antennas are composed of two linear antenna elements adjacent to each other among four linear antenna elements arranged so as to be parallel to each other. There are 3 sets of array antennas. In this way, by comparing the received signals corresponding to each of the three sets of array antennas selectively configured from the four linear antenna elements arranged so as to be parallel to each other, Optimize the direction of the wireless terminal Can be detected.
[0039] また、好適には、前記複数組のアレイアンテナは、互いに平行を成すように配設さ れた 4本の直線状アンテナ素子のうち選択される何れか 3本の直線状アンテナ素子 力 構成される 2組のアレイアンテナである。このようにすれば、互いに平行を成すよ うに配設された 4本の直線状アンテナ素子カゝら選択的に構成される 2組のアレイアン テナそれぞれに対応する受信信号を比較することで、前記無線端末の方向を好適に 検出することができる。 [0039] Preferably, the plurality of sets of array antennas are selected from four linear antenna elements arranged so as to be parallel to each other. Two sets of array antennas are constructed. In this way, by comparing the received signals corresponding to each of two sets of array antennas selectively configured from four linear antenna elements arranged so as to be parallel to each other, The direction of the wireless terminal can be detected suitably.
[0040] また、好適には、前記方向検出部は、予め定められた所定の相対角度範囲に対応 して前記指向性制御部により前記複数組のアレイアンテナそれぞれの送信指向性及 び Z又は受信指向性を制御し、各送信指向性及び Z又は受信指向性に対応して受 信される受信信号を比較することで前記無線端末の方向を検出するものである。この ようにすれば、予め方向検出の対象となる範囲を限定しておくことで、前記無線端末 の検出に要する時間を短縮することができる。 [0040] Further, preferably, the direction detection unit corresponds to a predetermined relative angle range determined in advance, and the directivity control unit performs transmission directivity and Z or reception of each of the plurality of sets of array antennas. The directivity is controlled, and the direction of the wireless terminal is detected by comparing the reception signals received corresponding to each transmission directivity and Z or reception directivity. In this way, the time required for detection of the wireless terminal can be shortened by limiting the range of the direction detection target in advance.
[0041] また、好適には、前記複数組のアレイアンテナそれぞれにより送信及び Z又は受信 を行った結果、受信される受信信号を比較することで障害物の存在する方向を検出 する障害物方向検出部、又は予め障害物の方向が既知である場合はその障害物の 方向を設定する障害物方向設定部を備え、前記方向検出部は、その障害物方向検 出部により障害物が検出された方向、又は前記障害物方向設定部に設定された方 向を除外して前記無線端末の方向を検出するものである。このようにすれば、マルチ パス発生の原因となる障害物が存在する方向を避けることで、前記無線端末の方向 を好適に検出することができる。 [0041] Preferably, the obstacle direction detection detects the direction in which the obstacle exists by comparing the received signals received as a result of transmission and Z or reception by each of the plurality of sets of array antennas. Or an obstacle direction setting unit for setting the direction of the obstacle when the direction of the obstacle is known in advance, and the direction detection unit detects the obstacle by the obstacle direction detection unit. The direction of the wireless terminal is detected by excluding the direction or the direction set in the obstacle direction setting unit. In this way, the direction of the wireless terminal can be suitably detected by avoiding the direction in which the obstacle causing the multipath occurs.
[0042] また、好適には、前記方向検出装置は、検出対象である無線タグに向けて所定の 送信信号を送信すると共に、その送信信号に応答して前記無線タグから返信される 返信信号を受信することで前記無線タグの方向を検出する無線タグ方向検出装置で ある。このようにすれば、マルチパスの影響を軽減して好適な無線タグ方向の検出を 実現する無線タグ方向検出装置を提供することができる。 [0042] Preferably, the direction detection device transmits a predetermined transmission signal toward the detection target wireless tag and returns a response signal returned from the wireless tag in response to the transmission signal. The wireless tag direction detection device detects a direction of the wireless tag by receiving the wireless tag. In this way, it is possible to provide a wireless tag direction detection device that reduces the influence of multipath and realizes detection of a suitable wireless tag direction.
[0043] また、好適には、前記方向検出部は、前記送信信号の搬送波の周波数を変化させ 、各周波数に対応して受信される受信信号を比較することで前記無線タグの方向を
検出するものである。このようにすれば、複数の搬送波周波数それぞれにおける各受 信指向性に対応して受信される受信信号を比較してマルチパスの影響が少ない搬 送波周波数による受信結果を用いることで、前記無線タグの方向を好適に検出する ことができる。 [0043] Preferably, the direction detection unit changes the frequency of the carrier wave of the transmission signal and compares the reception signal received corresponding to each frequency to determine the direction of the wireless tag. It is to detect. In this way, by comparing the reception signals received corresponding to the respective reception directivities at each of the plurality of carrier frequencies, and using the reception result at the carrier frequency with less multipath effect, the radio The direction of the tag can be detected suitably.
図面の簡単な説明 Brief Description of Drawings
[図 1]本発明の方向検出装置が好適に用いられる無線タグ通信システムについて説 明する図である。 FIG. 1 is a diagram for explaining a wireless tag communication system in which the direction detection device of the present invention is preferably used.
[図 2]本第 1発明の方向検出装置の好適な実施例である無線タグ通信装置の構成を 説明する図である。 FIG. 2 is a diagram for explaining the configuration of a wireless tag communication device which is a preferred embodiment of the direction detection device of the first invention.
[図 3]図 2の無線タグ通信装置に備えられた送受信モジュールの構成を詳しく説明す る図である。 3 is a diagram illustrating in detail the configuration of a transmission / reception module provided in the RFID tag communication apparatus of FIG. 2.
[図 4]図 2の無線タグ通信装置の検出対象の無線端末である無線タグに備えられた 無線タグ回路素子の構成を説明する図である。 4 is a diagram illustrating a configuration of a wireless tag circuit element provided in a wireless tag that is a wireless terminal to be detected by the wireless tag communication device of FIG. 2.
[図 5]図 1の無線タグ通信システムが室内において運用される場合に発生するマルチ パスについて説明する図である。 FIG. 5 is a diagram for explaining multipath that occurs when the RFID tag communication system of FIG. 1 is operated indoors.
[図 6]図 2の無線タグ通信装置により第 1の角度を所定角度ずつ段階的に変化させつ つその第 1の角度に対応する指向性方向とした場合において受信される受信信号の 信号強度と、各第 1の角度から所定の偏差角度ずらした第 2の角度に対応する指向 性方向とした場合において受信される受信信号の信号強度とを対比して示す図であ る。 [FIG. 6] The signal strength of the received signal received when the RFID tag communication device of FIG. 2 changes the first angle stepwise by a predetermined angle and sets the directivity direction corresponding to the first angle. FIG. 6 is a diagram showing a comparison between the signal strength of a received signal received in the case of a directivity direction corresponding to a second angle that is shifted from each first angle by a predetermined deviation angle.
[図 7]図 2の無線タグ通信装置による方向検出制御において第 1の角度に対応する 指向性方向とした場合において受信される受信信号の信号強度が所定値以下だつ た場合には、その第 1の角度力 所定の偏差角度ずらした第 2の角度に対応する指 向性制御及び無線信号の送信及び Z又は受信制御を行わないことを説明する図で ある。 [FIG. 7] If the signal strength of the received signal is less than or equal to the predetermined value when the directionality control corresponding to the first angle is set in the direction detection control by the RFID tag communication apparatus of FIG. FIG. 6 is a diagram for explaining that directivity control and radio signal transmission and Z or reception control corresponding to a second angle shifted by a predetermined deviation angle are not performed.
[図 8]図 2の無線タグ通信装置によるタグ方向検出制御の一例の要部を説明するフロ 一チャートである。 FIG. 8 is a flowchart for explaining a main part of an example of tag direction detection control by the wireless tag communication device of FIG. 2.
[図 9]図 2の無線タグ通信装置によるタグ方向検出制御の他の一例の要部を説明す
るフローチャートである。 FIG. 9 illustrates a main part of another example of tag direction detection control by the RFID tag communication apparatus of FIG. It is a flowchart.
[図 10]図 2の無線タグ通信装置によるタグ方向検出制御の更に別の一例の要部を説 明するフローチャートである。 FIG. 10 is a flowchart for explaining a main part of yet another example of tag direction detection control by the wireless tag communication device of FIG.
[図 11]図 2の無線タグ通信装置によるタグ方向検出制御の更に別の一例の要部を説 明するフローチャートである。 FIG. 11 is a flowchart for explaining a main part of yet another example of tag direction detection control by the wireless tag communication device of FIG. 2.
[図 12]図 2の無線タグ通信装置によるタグ方向検出制御の更に別の一例の要部を説 明するフローチャートである。 FIG. 12 is a flowchart for explaining a main part of still another example of tag direction detection control by the wireless tag communication device of FIG. 2.
[図 13]図 2の無線タグ通信装置によるタグ方向検出制御の更に別の一例の要部を説 明するフローチャートである。 FIG. 13 is a flowchart for explaining a main part of yet another example of tag direction detection control by the wireless tag communication device of FIG. 2.
[図 14]図 2の無線タグ通信装置によるタグ方向検出制御の更に別の一例の要部を説 明するフローチャートである。 FIG. 14 is a flowchart for explaining a main part of still another example of tag direction detection control by the wireless tag communication device of FIG.
圆 15]本第 2発明の方向検出装置の好適な実施例である無線タグ通信装置の構成 を説明する図である。 [15] FIG. 15 is a diagram illustrating a configuration of a wireless tag communication device which is a preferred embodiment of the direction detection device of the second invention.
[図 16]図 1の無線タグ通信システムが室内にお 、て運用される場合に発生するマル チパスについて説明する図である。 FIG. 16 is a diagram illustrating a multipath that occurs when the RFID tag communication system of FIG. 1 is operated indoors.
圆 17]図 15の無線タグ通信装置に備えられた複数のアンテナ素子によって構成され る複数組のアレイアンテナで同様に指向性を変化させていった場合における受信信 号の信号強度の違いを説明する図であり、各指向性方向に応じた受信信号の信号 強度を矢印で示している。 圆 17] Explain the difference in signal strength of received signals when the directivity is changed in the same way with multiple sets of array antennas composed of multiple antenna elements provided in the RFID tag communication device of Fig. 15. The signal strength of the received signal corresponding to each directivity direction is indicated by an arrow.
圆 18]図 15の無線タグ通信装置に備えられた複数のアンテナ素子によって構成され る複数組のアレイアンテナで同様に指向性を変化させていった場合における受信信 号の信号強度の違いを説明する図であり、各指向性方向に応じた受信信号の信号 強度を矢印で示している。 圆 18] Explain the difference in signal strength of received signals when the directivity is similarly changed in multiple sets of array antennas composed of multiple antenna elements provided in the RFID tag communication device of FIG. The signal strength of the received signal corresponding to each directivity direction is indicated by an arrow.
[図 19]図 15の無線タグ通信装置によるタグ方向検出制御の一例の要部を説明する フローチャートである。 FIG. 19 is a flowchart for explaining a main part of an example of tag direction detection control by the wireless tag communication device of FIG.
[図 20]図 15の無線タグ通信装置によるタグ方向検出制御の他の一例の要部を説明 するフローチャートである。 FIG. 20 is a flowchart for explaining a main part of another example of tag direction detection control by the wireless tag communication device of FIG.
[図 21]図 15の無線タグ通信装置によるタグ方向検出制御の更に別の一例の要部を
説明するフローチャートである。 [FIG. 21] The main part of still another example of tag direction detection control by the RFID tag communication apparatus of FIG. It is a flowchart to explain.
[図 22]図 15の無線タグ通信装置によるタグ方向検出制御の更に別の一例の要部を 説明するフローチャートである。 22 is a flowchart for explaining a main part of yet another example of tag direction detection control by the wireless tag communication device of FIG.
[図 23]図 15の無線タグ通信装置によるタグ方向検出制御の更に別の一例の要部を 説明するフローチャートである。 FIG. 23 is a flowchart for explaining a main part of still another example of tag direction detection control by the wireless tag communication device of FIG. 15.
[図 24]図 15の無線タグ通信装置によるタグ方向検出制御の更に別の一例の要部を 説明するフローチャートである。 FIG. 24 is a flowchart for explaining a main part of still another example of tag direction detection control by the wireless tag communication apparatus of FIG.
[図 25]本第 2発明の方向検出装置の他の好適な実施例である無線タグ通信装置の 構成を説明する図である。 FIG. 25 is a diagram for explaining the configuration of a wireless tag communication device which is another preferred embodiment of the direction detection device of the second invention.
[図 26]本第 2発明の方向検出装置の更に別の好適な実施例である無線タグ通信装 置の構成を説明する図である。 FIG. 26 is a diagram for explaining the configuration of a wireless tag communication device which is still another preferred embodiment of the direction detection device according to the second invention.
符号の説明 Explanation of symbols
[0045] 10:無線タグ通信システム、 12、 93、 94、 96:無線タグ通信装置 (方向検出装置)、 14:無線タグ (無線端末)、 16:アレイアンテナ、 20:搬送波発生部、 22:搬送波増幅 部、 24:送受信モジュール、 26:アンテナ素子、 28:受信信号合成部、 30:可変増幅 部、 32:ホモダイン検波回路、 34:I¾LPF、 36:1相八 0変換部、 38 :1相メモリ部( 記憶装置)、 40: Q相 LPF、 42: Q相 AZD変換部、 44: Q相メモリ部(記憶装置)、 4 6:送信回路切替部、 48:受信回路切替部、 50:送信データ生成部、 52:アンテナ選 択制御部、 54:指向性制御部、 56:信号強度検出部、 58:障害物方向検出部、 59: 障害物方向設定部、 60:方向検出部、 62:送信移相部、 64:送信アンプ、 66:送受 信分離部、 68:フィルタ、 70:受信移相部、 72:無線タグ回路素子、 74:アンテナ部、 76:IC回路部、 78:整流部、 80:電源部、 82:クロック抽出部、 84:メモリ部、 86:変 復調部、 88:制御部、 90:室、 92:壁(障害物) [0045] 10: wireless tag communication system, 12, 93, 94, 96: wireless tag communication device (direction detection device), 14: wireless tag (wireless terminal), 16: array antenna, 20: carrier wave generation unit, 22: Carrier amplifier, 24: Transmitter / receiver module, 26: Antenna element, 28: Received signal synthesizer, 30: Variable amplifier, 32: Homodyne detector, 34: I¾LPF, 36: 1 phase 8 0 converter, 38: 1 phase Memory part (storage device), 40: Q phase LPF, 42: Q phase AZD conversion part, 44: Q phase memory part (storage device), 4 6: Transmission circuit switching part, 48: Reception circuit switching part, 50: Transmission Data generation unit, 52: Antenna selection control unit, 54: Directivity control unit, 56: Signal strength detection unit, 58: Obstacle direction detection unit, 59: Obstacle direction setting unit, 60: Direction detection unit, 62: Transmit phase shifter, 64: Transmit amplifier, 66: Transmit / receive separation unit, 68: Filter, 70: Receive phase shift unit, 72: RFID circuit element, 74: Antenna unit, 76: IC circuit unit, 78: Rectifier unit , 8 0: Power supply unit, 82: Clock extraction unit, 84: Memory unit, 86: Modulation / demodulation unit, 88: Control unit, 90: Room, 92: Wall (obstacle)
発明を実施するための最良の形態 BEST MODE FOR CARRYING OUT THE INVENTION
[0046] 以下、本発明の好適な実施例を図面に基づいて詳細に説明する。 Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.
実施例 Example
[0047] 図 1は、本発明の方向検出装置が好適に用いられる無線タグ通信システム 10につ いて説明する図である。この無線タグ通信システム 10は、本第 1発明の方向検出装
置の一実施例である無線タグ通信装置 12と、その無線タグ通信装置 12の検出対象 の無線端末である単数乃至は複数(図 1では単数)の無線タグ 14とから構成される所 謂 RFID (Radio Frequency Identification)システムであり、上記無線タグ通信装置 12 はその RFIDシステムの質問器として、上記無線タグ 14は応答器としてそれぞれ機 能する。すなわち、上記無線タグ通信装置 12から質問波 F (送信信号)が上記無線 タグ 14に向けて送信されると、その質問波 Fを受信した上記無線タグ 14において所 定のコマンド (送信データ)によりその質問波 Fが変調され、応答波 F (返信信号)と して上記無線タグ通信装置 12に向けて返信されることで、その無線タグ通信装置 12 と無線タグ 14との間で情報の通信が行われる。斯カる通信により、上記無線タグ通信 装置 12に対する無線タグ 14の方向乃至は位置が検出される。この無線タグ通信シ ステム 10は、例えば、所定の通信領域内における物品の管理等に用いられるもので あり、上記無線タグ 14は、好適には、管理対象である物品に貼られる等してその物 品と一体的に設けられている。 FIG. 1 is a diagram illustrating a radio tag communication system 10 in which the direction detection device of the present invention is preferably used. The RFID tag communication system 10 is a direction detection device of the first invention. A RFID tag communication device 12 that is one embodiment of the device and a single or plural (single in FIG. 1) wireless tags 14 that are wireless terminals to be detected by the RFID tag communication device 12, so-called RFID (Radio Frequency Identification) system, the RFID tag communication device 12 functions as an interrogator of the RFID system, and the RFID tag 14 functions as a responder. That is, when the interrogation wave F (transmission signal) is transmitted from the radio tag communication device 12 toward the radio tag 14, the radio tag 14 that has received the interrogation wave F uses a predetermined command (transmission data). The interrogation wave F is modulated, and a response wave F (reply signal) is sent back to the RFID tag communication device 12 to communicate information between the RFID tag communication device 12 and the RFID tag 14. Is done. Through such communication, the direction or position of the wireless tag 14 relative to the wireless tag communication device 12 is detected. The wireless tag communication system 10 is used, for example, for management of articles in a predetermined communication area, and the wireless tag 14 is preferably attached to an article to be managed. It is integrated with the product.
図 2は、上記無線タグ通信装置 12の構成を説明する図である。この図 2に示すよう に、本実施例の無線タグ通信装置 12は、後述する方向検出部 60からの指令に応じ て所定の周波数の搬送波を発生させる搬送波発生部 20と、その搬送波発生部 20か ら出力される搬送波を増幅する搬送波増幅部 22と、その搬送波増幅部 22から供給 される搬送波に基づく送信信号を対応するアンテナ素子 26から送信すると共にその アンテナ素子 26により受信される受信信号を処理する複数(図 2では 3つ)の送受信 モジュール 24a、 24b、 24c (以下、特に区別しない場合には単に送受信モジュール 24と称する)と、各送受信モジュール 24a、 24b、 24cに対応して設けられた送受信 共用のアンテナ素子 26a、 26b、 26c (以下、特に区別しない場合には単にアンテナ 素子 26と称する)と、上記複数の送受信モジュール 24から供給される受信信号を合 成 (加算)する合波部である受信信号合成部 28と、その受信信号合成部 28から供給 される合成信号を増幅する可変増幅部 30と、その可変増幅部 30から供給される合 成信号をホモダイン検波するホモダイン検波回路 32と、そのホモダイン検波回路 32 力も出力される I相信号(同相成分)のうち所定の周波数帯域の信号のみ通過させる I 相 LPF (Low Pass Filter) 34と、その I相 LPF34を通過した I相信号をディジタル変換
する I相 AZD変換部 36と、その I相 AZD変換部 36によりディジタル変換された信号 を記憶する I相メモリ部 38と、上記ホモダイン検波回路 32から出力される Q相信号( 直交成分)のうち所定の周波数帯域の信号のみ通過させる Q相 LPF40と、その Q相 LPF40を通過した Q相信号をディジタル変換する Q相 AZD変換部 42と、その Q相 AZD変換部 42によりディジタル変換された信号を記憶する Q相メモリ部 44とを、備 えて構成されている。また、前記無線タグ 14の方向を検出する方向検出制御を行う ために、送信データ生成部 50、指向性制御部 54、信号強度検出部 56、障害物方 向検出部 58、障害物方向設定部 59、及び方向検出部 60を備えている。 FIG. 2 is a diagram illustrating the configuration of the wireless tag communication device 12. As shown in FIG. 2, the RFID tag communication apparatus 12 of the present embodiment includes a carrier generation unit 20 that generates a carrier wave of a predetermined frequency in response to a command from a direction detection unit 60 described later, and the carrier generation unit 20 A carrier wave amplification unit 22 that amplifies the carrier wave output from the carrier wave, and a transmission signal based on the carrier wave supplied from the carrier wave amplification unit 22 is transmitted from the corresponding antenna element 26 and a reception signal received by the antenna element 26 is received. A plurality of transmission / reception modules 24a, 24b, 24c (3 in FIG. 2) to be processed (hereinafter simply referred to as transmission / reception modules 24 unless otherwise specified) are provided corresponding to each transmission / reception module 24a, 24b, 24c. The antenna elements 26a, 26b, and 26c shared by transmission and reception (hereinafter simply referred to as the antenna element 26 unless otherwise specified) and the reception elements supplied from the plurality of transmission / reception modules 24. Received signal combining unit 28, which is a combining unit for combining (adding) signals, variable amplifying unit 30 for amplifying the combined signal supplied from received signal combining unit 28, and supplied from variable amplifying unit 30 A homodyne detection circuit 32 that performs homodyne detection of the composite signal, and an I-phase LPF (Low Pass Filter) 34 that passes only signals in a predetermined frequency band among the I-phase signals (in-phase components) that are also output from the homodyne detection circuit 32 The I-phase signal that passed through the I-phase LPF34 is digitally converted. Of the I-phase AZD conversion unit 36, the I-phase memory unit 38 that stores the signal digitally converted by the I-phase AZD conversion unit 36, and the Q-phase signal (orthogonal component) output from the homodyne detection circuit 32 A Q-phase LPF40 that passes only signals in the specified frequency band, a Q-phase AZD converter 42 that digitally converts the Q-phase signal that has passed through the Q-phase LPF40, and a signal digitally converted by the Q-phase AZD converter 42 Q memory unit 44 for storing. In addition, in order to perform direction detection control for detecting the direction of the wireless tag 14, a transmission data generation unit 50, a directivity control unit 54, a signal intensity detection unit 56, an obstacle direction detection unit 58, an obstacle direction setting unit 59 and a direction detector 60 are provided.
[0049] 前記アンテナ素子 26は、例えば、ダイポールアンテナ等の直線状アンテナ素子で あり、好適には、複数の直線状アンテナ素子 26が同一平面内に互いに平行を成す ように且つ等間隔で配設されて 、る。本実施例の無線タグ通信装置 12にお 、ては、 それら複数の直線状アンテナ素子 26により送受信共用のアレイアンテナ 16が構成さ れる。また、好適には、前記アレイアンテナ 16を構成する複数本の直線状アンテナ 素子 26のうち、相互に最も離れて配設された直線状アンテナ素子 26相互間の距離 すなわちアンテナ素子 26a及び 26c相互間の距離は、前記搬送波発生部 20により 発生させられる搬送波の波長以下とされる。 [0049] The antenna element 26 is, for example, a linear antenna element such as a dipole antenna, and is preferably arranged so that the plurality of linear antenna elements 26 are parallel to each other in the same plane and at equal intervals. It has been. In the RFID tag communication apparatus 12 of the present embodiment, the array antenna 16 that is used for both transmission and reception is constituted by the plurality of linear antenna elements 26. Preferably, among the plurality of linear antenna elements 26 constituting the array antenna 16, the distance between the linear antenna elements 26 arranged farthest from each other, that is, between the antenna elements 26a and 26c. Is less than the wavelength of the carrier wave generated by the carrier wave generator 20.
[0050] 図 3は、前記送受信モジュール 24の構成を詳しく説明する図である。この図 3に示 すように、前記送受信モジュール 24は、前記搬送波増幅部 22から供給される搬送 波の位相を制御するための可変移相器である送信移相部 62と、その送信移相部 62 力 出力される搬送波を所定の送信データにより変調して前記送信信号を出力する ための可変ゲインアンプである送信アンプ 64と、その送信アンプ 64と前記アンテナ 素子 26との間の信号伝達経路に設けられたフィルタ 68と、上記送信アンプ 64から出 力される送信信号をそのフィルタ 68を介して前記アンテナ素子 26へ供給すると共に 、そのアンテナ素子 26により受信されて上記フィルタ 68を介して供給される受信信 号を受信アンプ 70へ供給する送受信分離部 66と、その送受信分離部 66から供給さ れる受信信号の位相を制御するための可変移相器である受信移相部 70とを、備え ている。 FIG. 3 is a diagram for explaining the configuration of the transmission / reception module 24 in detail. As shown in FIG. 3, the transmission / reception module 24 includes a transmission phase shifter 62 that is a variable phase shifter for controlling the phase of the carrier wave supplied from the carrier wave amplification unit 22, and its transmission phase shift. 62 A transmission amplifier 64 that is a variable gain amplifier for modulating the output carrier wave with predetermined transmission data and outputting the transmission signal, and a signal transmission path between the transmission amplifier 64 and the antenna element 26 And a transmission signal output from the transmission amplifier 64 is supplied to the antenna element 26 via the filter 68, and is received by the antenna element 26 and supplied via the filter 68. Transmission / reception separating unit 66 for supplying the received signal to reception amplifier 70, and reception phase shifting unit 70, which is a variable phase shifter for controlling the phase of the received signal supplied from transmission / reception separating unit 66, , It is equipped.
[0051] 図 4は、前記無線タグ 14に備えられた無線タグ回路素子 72の構成を説明する図で
ある。この図 4に示すように、上記無線タグ回路素子 72は、前記無線タグ通信装置 1 2との間で信号の送受信を行うためのアンテナ部 74と、そのアンテナ部 74により受信 された信号を処理するための IC回路部 76とを、備えて構成されている。その IC回路 部 76は、上記アンテナ部 74により受信された前記無線タグ通信装置 12からの質問 波 Fを整流する整流部 78と、その整流部 78により整流された質問波 Fのエネルギを 蓄積するための電源部 80と、上記アンテナ部 74により受信された搬送波力もクロック 信号を抽出して制御部 88に供給するクロック抽出部 82と、所定の情報信号を記憶し 得る情報記憶部として機能するメモリ部 84と、上記アンテナ部 74に接続されて信号 の変調及び復調を行う変復調部 86と、上記整流部 78、クロック抽出部 82、及び変復 調部 86等を介して上記無線タグ回路素子 72の作動を制御するための制御部 88とを 、機能的に含んでいる。この制御部 88は、前記無線タグ通信装置 12と通信を行うこ とにより上記メモリ部 84に上記所定の情報を記憶する制御や、上記アンテナ部 74に より受信された質問波 Fを上記変復調部 86にお 、て上記メモリ部 84に記憶された 情報信号に基づ 、て変調したうえで応答波 Fとして上記アンテナ部 74から反射返信 する制御等の基本的な制御を実行する。 FIG. 4 is a diagram for explaining the configuration of the RFID circuit element 72 provided in the RFID tag 14. is there. As shown in FIG. 4, the RFID circuit element 72 has an antenna unit 74 for transmitting and receiving signals to and from the RFID tag communication apparatus 12, and processes a signal received by the antenna unit 74. And an IC circuit unit 76 for the purpose. The IC circuit unit 76 rectifies the interrogation wave F received from the RFID tag communication apparatus 12 received by the antenna unit 74, and stores the energy of the interrogation wave F rectified by the rectification unit 78. Power supply unit 80, a carrier wave force received by the antenna unit 74, a clock extraction unit 82 that extracts a clock signal and supplies it to the control unit 88, and a memory that functions as an information storage unit that can store a predetermined information signal Unit 84, modulation / demodulation unit 86 connected to the antenna unit 74 to modulate and demodulate signals, the RFID circuit element 72 via the rectification unit 78, the clock extraction unit 82, the modulation / demodulation unit 86, etc. And a control unit 88 for controlling the operation of the apparatus. The control unit 88 performs control for storing the predetermined information in the memory unit 84 by communicating with the RFID tag communication device 12, and the interrogation wave F received by the antenna unit 74. In 86, basic control such as control of reflecting and returning the response wave F as the response wave F from the antenna unit 74 is executed based on the information signal stored in the memory unit 84.
[0052] 図 2に戻って、前記送信データ生成部 50は、前記搬送波発生部 20により発生させ られる搬送波に乗せて前記無線タグ 14へ送信するための送信データを生成して各 送受信モジュール 24における送信アンプ 64へ供給する。その送信アンプ 64では、 上記送信データ生成部 50から供給される送信データに基づいて変調が行われて送 信信号とされ、前記フィルタ 68等を介して前記アンテナ素子 26から送信される。 Returning to FIG. 2, the transmission data generation unit 50 generates transmission data to be transmitted to the wireless tag 14 on the carrier wave generated by the carrier wave generation unit 20, and in each transmission / reception module 24. Supply to transmission amplifier 64. In the transmission amplifier 64, modulation is performed based on the transmission data supplied from the transmission data generating unit 50 to obtain a transmission signal, which is transmitted from the antenna element 26 through the filter 68 and the like.
[0053] 前記指向性制御部 54は、前記複数のアンテナ素子 26から構成されるアレイアンテ ナ 16の送信指向性及び Z又は受信指向性を制御する。具体的には、各送受信モジ ユール 24における送信移相部 62を介してそれぞれ対応するアンテナ素子 26から送 信される送信信号の位相を制御することで、前記アレイアンテナ 16の送信指向性を 制御する。また、各送受信モジュール 24における受信移相部 70を介してそれぞれ 対応するアンテナ素子 26により受信される受信信号の位相を制御することで、前記 アレイアンテナ 16の受信指向性を制御する。 The directivity control unit 54 controls the transmission directivity and Z or reception directivity of the array antenna 16 composed of the plurality of antenna elements 26. Specifically, the transmission directivity of the array antenna 16 is controlled by controlling the phase of the transmission signal transmitted from the corresponding antenna element 26 via the transmission phase shifter 62 in each transmission / reception module 24. To do. Further, the reception directivity of the array antenna 16 is controlled by controlling the phase of the reception signal received by the corresponding antenna element 26 via the reception phase shift unit 70 in each transmission / reception module 24.
[0054] 前記信号強度検出部 56は、前記アレイアンテナ 16により受信される受信信号の信
号強度を検出する。具体的には、前記 I相メモリ部 38に記憶された I相信号及び Q相 メモリ部 44に記憶された Q相信号を読み出し、それら I相信号及び Q相信号それぞれ の二乗の和の平方根を算出すること等によりそれら I相信号及び Q相信号に相当する 受信信号の信号強度を検出する。 [0054] The signal strength detection unit 56 receives a signal of a reception signal received by the array antenna 16. Detect the strength of the signal. Specifically, the I-phase signal stored in the I-phase memory unit 38 and the Q-phase signal stored in the Q-phase memory unit 44 are read, and the square root of the sum of the squares of the I-phase signal and the Q-phase signal is calculated. The signal strength of the received signal corresponding to the I-phase signal and Q-phase signal is detected by calculation.
[0055] 前記障害物方向検出部 58は、前記アレイアンテナ 16により送信あるいは受信を行 つた結果、受信される受信信号を比較することで障害物の存在する方向を検出する 。この検出は、好適には、前記信号強度検出部 56の検出結果に基づいて行われる 。すなわち、前記障害物方向検出部 58は、前記アレイアンテナ 16により送信あるい は受信を行った結果、受信される受信信号の信号強度が極小又は極大となる方向を 上記障害物が存在する方向として検出する。また、前記障害物方向設定部 59は障 害物方向が既知のときにその方向が設定される。 The obstacle direction detector 58 detects the direction in which the obstacle exists by comparing the received signals received as a result of transmission or reception by the array antenna 16. This detection is preferably performed based on the detection result of the signal intensity detection unit 56. That is, the obstacle direction detection unit 58 sets the direction in which the received signal strength is minimized or maximized as a direction in which the obstacle exists as a result of transmission or reception by the array antenna 16. To detect. The obstacle direction setting unit 59 sets the direction when the obstacle direction is known.
[0056] 前記方向検出部 60は、前記指向性制御部 54により前記アレイアンテナ 16の送信 指向性及び Z又は受信指向性を第 1の角度に対応する指向性方向とした場合にお いて受信される受信信号と、その第 1の角度から所定の偏差角度 (微小角度)ずらし た第 2の角度に対応する指向性方向とした場合において受信される受信信号とを、 比較することで前記無線タグ 14の方向を検出する。以下、この方向検出部 60による 無線タグ 14の方向検出制御について詳述する。 [0056] The direction detection unit 60 is received by the directivity control unit 54 when the transmission directivity and Z or reception directivity of the array antenna 16 is set to the directivity direction corresponding to the first angle. The radio tag is compared by comparing a received signal received in a directivity direction corresponding to a second angle shifted from the first angle by a predetermined deviation angle (minute angle). Detect 14 directions. Hereinafter, the direction detection control of the wireless tag 14 by the direction detection unit 60 will be described in detail.
[0057] 図 5は、前記無線タグ通信システム 10が室 90内において運用される場合に発生す るマルチパスについて説明する図である。この図 5に示すように、前記無線タグ通信 システム 10が四方に障害物 (検出対象である無線タグ 14以外の電波反射体)である 壁 92を有する室 90内において運用される場合、その壁 92に起因する反射や回折 等により直接波の経路とは別に所謂マルチパスが発生することが考えられる。図 5で は、前記アレイアンテナ 16の送信指向性及び Z又は受信指向性を所定の第 1の角 度に対応する指向性方向とした場合における直接波及びマルチパスを実線矢印で、 その第 1の角度から所定の偏差角度ずらした第 2の角度に対応する指向性方向とし た場合における直接波及びマルチパスを破線矢印でそれぞれ示して ヽる。このよう にマルチノ スが発生した場合、そのマルチノ スと直接波とは経路によって異なった 位相となるため、その直接波経路の信号がマルチパス経路の信号により強められたり
、弱められたりする。また、マルチパスにより直接波の届かない場所にも電波が届くよ うになる。 FIG. 5 is a diagram for explaining multipath that occurs when the RFID tag communication system 10 is operated in the room 90. As shown in FIG. 5, when the RFID tag communication system 10 is operated in a room 90 having a wall 92 that is an obstacle (a radio wave reflector other than the RFID tag 14 to be detected) on all sides, the wall It is conceivable that a so-called multipath is generated in addition to the direct wave path due to reflection and diffraction caused by 92. In FIG. 5, direct waves and multipaths are indicated by solid line arrows when the transmission directivity and Z or reception directivity of the array antenna 16 are set to directivity directions corresponding to a predetermined first angle. The direct wave and multipath in the case of the directivity direction corresponding to the second angle shifted from the angle by a predetermined deviation angle are indicated by dashed arrows. When a multinos occurs in this way, the multinos and the direct wave have different phases depending on the path, so the signal of the direct wave path is strengthened by the signal of the multipath path. Or weakened. Also, due to multipath, radio waves can reach places where direct waves do not reach.
[0058] 図 6は、前記第 1の角度を所定角度ずつ段階的に変化させつつその第 1の角度に 対応する指向性方向とした場合において受信される受信信号の信号強度と、各第 1 の角度力 所定の偏差角度ずらした第 2の角度に対応する指向性方向とした場合に おいて受信される受信信号の信号強度とを対比して示す図であり、前記第 1の角度 に対応する受信信号強度を実線で、第 2の角度に対応する受信信号強度を破線で それぞれ示している。この図 6は、前記第 1の角度を所定の基準方向例えばアンテナ 素子 26が配設された平面に垂直且つ中央に配設されたアンテナ素子 26bを通る直 線で示される方向に対して—40° 力 40° まで 10° ずつ段階的に変化させた場合 を示しており、そのように、前記方向検出部 60は、好適には、予め定められた所定の 相対角度範囲に対応して前記指向性制御部 54により前記アレイアンテナ 16の送信 指向性及び Z又は受信指向性を所定角度ずつ段階的に変化させる制御を行い、各 送信指向性及び Z又は受信指向性に対応して受信される受信信号を比較すること で前記無線タグ 14の方向を検出する。また、前記偏差角度すなわち前記第 2の角度 の第 1の角度からのずれは、好適には、上記第 1の角度の段階的な変化分である所 定角度の 1Z10以上 1Z5以下であり、図 6に示す例では 1° である。一般にアレイァ ンテナの指向性方向を 1乃至 2° の範囲内でずらしても直接波による受信信号強度 はほとんど変わらないが、直接波と間接波との経路差が変化することからマルチパス の影響は大きく変化し、図 6に示すように各指向性に対応する受信信号の信号強度 には顕著な差が発生する。本実施例の無線タグ通信装置 12における方向検出部 6 0は、このように前記アレイアンテナ 16の指向性方向を 1乃至 2° の範囲内でずらし て各指向性方向に対応する受信信号を比較することで、マルチパスの影響が少な!、 角度に対応する指向性方向を判定する。また、前記偏差角度は、好適には、前記無 線タグ 14の方向検出における許容誤差角度以下とされる。 FIG. 6 shows signal strengths of received signals received when the first angle is changed stepwise by a predetermined angle and the directivity direction corresponding to the first angle is set. FIG. 6 is a diagram showing the signal strength of the received signal in comparison with the directivity direction corresponding to the second angle shifted by a predetermined deviation angle, corresponding to the first angle The received signal strength corresponding to the second angle is indicated by a broken line, and the received signal strength corresponding to the second angle is indicated by a broken line. FIG. 6 shows that the first angle is -40 with respect to a predetermined reference direction, for example, a direction indicated by a straight line passing through the antenna element 26b disposed in the center and perpendicular to the plane in which the antenna element 26 is disposed. The figure shows a case where the force is changed stepwise by 10 ° up to 40 °, and as such, the direction detection unit 60 preferably corresponds to the directivity corresponding to a predetermined relative angle range. The reception control unit 54 controls the array antenna 16 so that the transmission directivity and Z or reception directivity of the array antenna 16 are changed step by step by a predetermined angle, and is received corresponding to each transmission directivity and Z or reception directivity. The direction of the wireless tag 14 is detected by comparing the signals. Further, the deviation angle, that is, the deviation of the second angle from the first angle is preferably a predetermined angle of 1Z10 or more and 1Z5 or less, which is a step change of the first angle. In the example shown in Fig. 6, it is 1 °. Generally, even if the array antenna directivity direction is shifted within a range of 1 to 2 °, the received signal strength due to the direct wave is hardly changed, but the path difference between the direct wave and the indirect wave changes. As shown in Fig. 6, there is a significant difference in the signal strength of the received signal corresponding to each directivity. The direction detector 60 in the RFID tag communication apparatus 12 of the present embodiment compares the received signals corresponding to the respective directivity directions by shifting the directivity direction of the array antenna 16 within the range of 1 to 2 ° in this way. By doing so, the influence of multipath is small! Determine the directivity direction corresponding to the angle. The deviation angle is preferably equal to or smaller than an allowable error angle in the direction detection of the radio tag 14.
[0059] 前記方向検出部 60は、具体的には、前記指向性制御部 54により前記第 1の角度 を所定角度ずつ(例えば、上記基準となる方向に対して 40° 力 40° まで 10° ずつ)段階的に変化させつつその第 1の角度に対応する指向性方向とした場合にお
いて受信される受信信号又はその信号強度と、その第 1の角度から所定の偏差角度 (例えば、 1乃至 2° 程度)ずらした第 2の角度に対応する指向性方向とした場合にお V、て受信される受信信号又はその信号強度とを、比較することで前記無線タグ 14の 方向を検出する。好適には、先ず、前記第 1の角度を所定角度ずつ段階的に変化さ せつつ前記指向性制御部 54により前記アレイアンテナ 16の送信指向性及び Z又は 受信指向性をそれぞれの第 1の角度に対応する指向性方向とした場合において受 信される受信信号又はその信号強度を前記 I相メモリ部 38及び Z又は Q相メモリ部 4 4等の記憶装置に記憶し、次に、前記第 1の角度を所定角度ずつ段階的に変化させ つつ前記指向性制御部 54により前記アレイアンテナ 16の送信指向性及び Z又は受 信指向性をそれぞれの第 1の角度力 所定の偏差角度ずらした第 2の角度に対応す る指向性方向とした場合において受信される受信信号又はその信号強度を前記 I相 メモリ部 38及び Z又は Q相メモリ部 44等の記憶装置に記憶し、その記憶装置に記憶 された受信信号又はその信号強度を読み出して比較することで前記無線タグ 14の 方向を検出する。換言すれば、先ず、前記第 1の角度に対応して前記指向性制御部 54により前記アレイアンテナ 16の指向性を前記所定の角度範囲で所定角度ずつ一 通り変化させて受信信号又はその信号強度を記憶する制御を行い、その後、前記第 2の角度に対応して前記指向性制御部 54により前記アレイアンテナ 16の指向性を 前記所定の角度範囲で所定角度ずつ一通り変化させて受信信号又はその信号強 度を記憶する制御を行う。また、この第 2の角度に対応する制御において、好適には 、先に行われた第 1の角度に対応する制御の結果が考慮され、図 7を用いて後述す るように一部の制御が省かれる。以下、斯カる無線タグ 14の方向検出制御を、図 8乃 至図 14のフローチャートを用いて説明する。なお、それら図 8乃至図 14のフローチヤ ートに示す制御において、共通するステップは同一の符号を付してその説明を省略 する。 [0059] Specifically, the direction detection unit 60 sets the first angle by a predetermined angle by the directivity control unit 54 (for example, 10 ° up to 40 ° force 40 ° with respect to the reference direction). If the directionality corresponding to the first angle is changed step by step, V when the received signal or its signal strength is received and the directivity direction corresponding to the second angle shifted from the first angle by a predetermined deviation angle (for example, about 1 to 2 °), V, The direction of the wireless tag 14 is detected by comparing the received signal or its signal strength. Preferably, first, the directivity control unit 54 changes the transmission directivity and Z or reception directivity of the array antenna 16 while changing the first angle step by step by a predetermined angle. Is stored in the storage device such as the I-phase memory unit 38 and Z or Q-phase memory unit 44, and then the first signal is received. The directivity control unit 54 changes the transmission directivity and the Z or reception directivity of the array antenna 16 with respective first angular forces and second deviations shifted by a predetermined deviation angle. The received signal or the signal strength received when the directivity direction corresponding to the angle is stored in the storage device such as the I-phase memory unit 38 and Z or Q-phase memory unit 44, and stored in the storage device. Received signal or its signal Detecting the direction of the wireless tag 14 by comparing reading in degrees. In other words, first, in response to the first angle, the directivity control unit 54 changes the directivity of the array antenna 16 in steps of the predetermined angle within the predetermined angle range, thereby receiving the received signal or its signal strength. Then, the directivity control unit 54 changes the directivity of the array antenna 16 in steps of a predetermined angle within the predetermined angle range corresponding to the second angle. Control to memorize the signal strength. Further, in the control corresponding to the second angle, preferably, the result of the control corresponding to the first angle previously performed is considered, and a part of the control is performed as will be described later with reference to FIG. Is omitted. Hereinafter, the direction detection control of the wireless tag 14 will be described with reference to the flowcharts of FIGS. In the control shown in the flow charts of FIGS. 8 to 14, common steps are denoted by the same reference numerals and description thereof is omitted.
前記方向検出部 60は、好適には、前記第 1の角度及び第 2の角度にそれぞれ対 応して前記 I相メモリ部 38及び Z又は Q相メモリ部 44に記憶された各受信信号につ いて前記信号強度検出部 56により検出される検出結果を一通り比較し、その検出結 果が最大値をとる送信指向性及び Z又は受信指向性に対応する方向を前記無線タ
グ 14の方向として検出する。図 8は、斯カる態様のタグ方向検出制御の要部を説明 するフローチャートであり、所定の周期で繰り返し実行されるものである。 Preferably, the direction detection unit 60 receives each received signal stored in the I-phase memory unit 38 and the Z-phase memory unit 44 corresponding to the first angle and the second angle, respectively. Then, the detection results detected by the signal strength detection unit 56 are compared one by one, and the direction corresponding to the transmission directivity and Z or reception directivity at which the detection result takes the maximum value is compared with the wireless tag. Detected as 14 direction. FIG. 8 is a flowchart for explaining a main part of the tag direction detection control of such a mode, which is repeatedly executed at a predetermined cycle.
図 8の制御では、先ず、ステップ (以下、ステップを省略する) S1において、指向性 方向を示す角度 Θが初期値である Θ とされる。次に、 S 2において、指向性方向を start In the control of FIG. 8, first, in step (hereinafter, step is omitted) S1, an angle Θ indicating the directivity direction is set to Θ which is an initial value. Next, in S 2, change the directivity direction to start
示す角度が 0となるように前記送信移相部 62及び Z又は受信移相部 70の設定が 行われ、検出対象である無線タグ 14に向けて送信信号を送信すると共に、その送信 信号に応答して前記無線タグ 14から返信される返信信号を受信する送受信処理が 行われる。次に、 S3において、 S2の送受信処理により受信された受信信号の信号 強度が検出されると共に、その検出結果 S が前記 I相メモリ部 38及び Z又は Q相メ モリ部 44に記憶される。次に、 S4において、指向性方向を示す角度 Θが所定値 Θ である力否かが判断される。この S4の判断が否定される場合には、 S5において、指 d The transmission phase shifter 62 and Z or the reception phase shifter 70 are set so that the angle shown is 0, and a transmission signal is transmitted toward the wireless tag 14 that is a detection target, and a response is made to the transmission signal. Then, a transmission / reception process for receiving a reply signal returned from the wireless tag 14 is performed. Next, in S3, the signal strength of the received signal received by the transmission / reception processing of S2 is detected, and the detection result S is stored in the I-phase memory unit 38 and the Z-phase or Q-phase memory unit 44. Next, in S4, it is determined whether or not the force Θ indicating the directivity direction is a predetermined value Θ. If the determination of S4 is negative, the finger d in S5
向性方向を示す角度 0に Δ 0が加算された後、 S2以下の処理が再び実行されるが 、 S4の判断が肯定される場合には、 S6において、指向性方向を示す角度 Θが初期 値である Θ とされる。次に、 S 7において、指向性方向を示す角度が Θ + 1となるよ start After Δ 0 is added to the angle 0 indicating the directional direction, the processing after S2 is executed again, but when the determination of S4 is affirmed, the angle Θ indicating the directional direction is initially set in S6. The value is Θ. Next, in S 7, the angle indicating the directivity direction is Θ + 1. start
うに前記送信移相部 62及び Z又は受信移相部 70の設定が行われ、検出対象であ る無線タグ 14に向けて送信信号を送信すると共に、その送信信号に応答して前記無 線タグ 14から返信される返信信号を受信する送受信処理が行われる。次に、 S8〖こ おいて、 S7の送受信処理により受信された受信信号の信号強度が検出されると共に 、その検出結果 S が前記 I相メモリ部 38及び Z又は Q相メモリ部 44に記憶される。 Thus, the transmission phase shifter 62 and Z or the reception phase shifter 70 are set to transmit a transmission signal to the wireless tag 14 to be detected, and in response to the transmission signal, the wireless tag Transmission / reception processing for receiving a reply signal returned from 14 is performed. Next, in S8, the signal strength of the received signal received by the transmission / reception processing in S7 is detected, and the detection result S is stored in the I-phase memory unit 38 and the Z-phase or Q-phase memory unit 44. The
Θ +1 Θ +1
次に、 S9において、指向性方向を示す角度 Θが所定値 Θ である力否かが判断さ end Next, in S9, it is determined whether or not the force directional angle Θ is a predetermined value Θ end
れる。この S9の判断が否定される場合には、 S10において、指向性方向を示す角度 0に Δ 0が加算された後、 S7以下の処理が再び実行される力 S9の判断が肯定さ れる場合には、前記方向検出部 60の動作に対応する S11において、前記 I相メモリ 部 38及び Z又は Q相メモリ部 44に記憶された受信信号強度 S 、 S が読み出され て全て比較され、最大値をとる受信信号強度に対応する Θが前記無線タグ 14の方 向として検出された後、本ルーチンが終了させられる。以上の制御において、 S2及 び S7が前記指向性制御部 54の動作に、 S3及び S8が前記信号強度検出部 56の動 作にそれぞれ対応する。
[0062] また、前記方向検出部 60は、好適には、前記第 1の角度及び第 2の角度にそれぞ れ対応して前記 I相メモリ部 38及び Z又は Q相メモリ部 44に記憶された各受信信号 について前記信号強度検出部 56により検出される検出結果を比較し、その検出結 果が前記第 1の角度に対応する指向性方向及び第 2の角度に対応する指向性方向 の何れにおいても所定の閾値以上となる送信指向性及び Z又は受信指向性に対応 する方向を前記無線タグ 14の方向として検出する。図 9は、斯カる態様のタグ方向検 出制御の要部を説明するフローチャートであり、所定の周期で繰り返し実行されるも のである。この制御において上述した S9の判断が肯定される場合には、前記方向検 出部 60の動作に対応する S12において、前記 I相メモリ部 38及び Z又は Q相メモリ 部 44に記憶された受信信号強度 S 、S が読み出されて比較され、そのいずれも It is. If the determination of S9 is negative, in S10, when Δ0 is added to the angle 0 indicating the directivity direction, and then the process of S7 and subsequent steps is executed again. In S11 corresponding to the operation of the direction detection unit 60, the received signal strengths S and S stored in the I-phase memory unit 38 and Z or Q-phase memory unit 44 are read and compared, and the maximum value is obtained. After Θ corresponding to the received signal strength taking the following is detected as the direction of the wireless tag 14, this routine is terminated. In the above control, S2 and S7 correspond to the operation of the directivity control unit 54, and S3 and S8 correspond to the operation of the signal intensity detection unit 56, respectively. Further, the direction detection unit 60 is preferably stored in the I-phase memory unit 38 and the Z-phase or Q-phase memory unit 44 corresponding to the first angle and the second angle, respectively. For each received signal, the detection result detected by the signal intensity detection unit 56 is compared, and the detection result indicates which of the directivity direction corresponding to the first angle and the directivity direction corresponding to the second angle. The direction corresponding to the transmission directivity and Z or reception directivity that is equal to or greater than a predetermined threshold is detected as the direction of the wireless tag 14. FIG. 9 is a flowchart for explaining a main part of the tag direction detection control of such a mode, which is repeatedly executed at a predetermined cycle. If the determination in S9 described above is affirmed in this control, the received signal stored in the I-phase memory unit 38 and Z or the Q-phase memory unit 44 in S12 corresponding to the operation of the direction detection unit 60. Intensities S and S are read and compared.
Θ Θ +1 Θ Θ +1
が所定の閾値 A以上である角度 Θに対応する方向が前記無線タグ 14の方向として 検出された後、本ルーチンが終了させられる。 Is detected as a direction of the wireless tag 14, the routine is terminated.
[0063] また、前記方向検出部 60は、好適には、前記第 1の角度及び第 2の角度にそれぞ れ対応して前記 I相メモリ部 38及び Z又は Q相メモリ部 44に記憶された各受信信号 について前記信号強度検出部 56により検出される検出結果を比較し、前記第 1の角 度に対応する指向性方向の検出結果と第 2の角度に対応する指向性方向の検出結 果との差が最も小さい角度に対応する方向を前記無線タグ 14の方向として検出する 。図 10は、斯かる態様のタグ方向検出制御の要部を説明するフローチャートであり、 所定の周期で繰り返し実行されるものである。この制御において前述した S9の判断 が肯定される場合には、前記方向検出部 60の動作に対応する S13において、前記 I 相メモリ部 38及び Z又は Q相メモリ部 44に記憶された受信信号強度 S 、 S が読 み出されてそれぞれ対応する s 、S の差が算出され、その差が最も小さい角度 0 [0063] Further, the direction detection unit 60 is preferably stored in the I-phase memory unit 38 and the Z-phase or Q-phase memory unit 44 corresponding to the first angle and the second angle, respectively. For each received signal, the detection result detected by the signal intensity detector 56 is compared, and the detection result of the directivity direction corresponding to the first angle and the detection result of the directivity direction corresponding to the second angle are compared. The direction corresponding to the angle having the smallest difference from the fruit is detected as the direction of the wireless tag 14. FIG. 10 is a flowchart for explaining a main part of the tag direction detection control of such a mode, which is repeatedly executed at a predetermined cycle. If the determination in S9 described above is affirmed in this control, the received signal strength stored in the I-phase memory unit 38 and Z or the Q-phase memory unit 44 in S13 corresponding to the operation of the direction detection unit 60. S and S are read and the corresponding difference between s and S is calculated.
Θ Θ +1 Θ Θ +1
に対応する方向が前記無線タグ 14の方向として検出された後、本ルーチンが終了さ せられる。 After the direction corresponding to is detected as the direction of the wireless tag 14, this routine is ended.
[0064] また、前記方向検出部 60は、好適には、前記第 1の角度及び第 2の角度にそれぞ れ対応して前記 I相メモリ部 38及び Z又は Q相メモリ部 44に記憶された各受信信号 について前記第 1の角度に対応する指向性方向及び第 2の角度に対応する指向性 方向それぞれに関して前記信号強度検出部 56により検出される検出結果を平均し、
その平均の大きな角度に対応する指向性方向において前記検出結果が最大値をと る送信指向性及び Z又は受信指向性に対応する方向を前記無線タグ 14の方向とし て検出する。図 11は、斯カる態様のタグ方向検出制御の要部を説明するフローチヤ ートであり、所定の周期で繰り返し実行されるものである。この制御において前述した S9の判断が肯定される場合には、前記方向検出部 60の動作に対応する S 14にお V、て、前記 I相メモリ部 38及び Z又は Q相メモリ部 44に記憶された受信信号強度 S Further, the direction detection unit 60 is preferably stored in the I-phase memory unit 38 and the Z-phase or Q-phase memory unit 44 corresponding to the first angle and the second angle, respectively. For each received signal, the detection results detected by the signal intensity detection unit 56 with respect to the directivity direction corresponding to the first angle and the directivity direction corresponding to the second angle are averaged, In the directivity direction corresponding to the average large angle, the direction corresponding to the transmission directivity and Z or reception directivity in which the detection result has the maximum value is detected as the direction of the wireless tag 14. FIG. 11 is a flowchart for explaining the main part of the tag direction detection control of such a mode, and is repeatedly executed at a predetermined cycle. If the determination of S9 described above is affirmed in this control, V is stored in S14 corresponding to the operation of the direction detection unit 60, and stored in the I-phase memory unit 38 and Z or the Q-phase memory unit 44. Received signal strength S
Θ Θ
、S が読み出されて S 、S それぞれについて平均値 (相加平均)が算出され、 S θ +1 Θ Θ +1 , S are read out, and the average value (arithmetic mean) is calculated for each of S 1 and S, and S θ +1 Θ Θ +1
、 が大き力つた方において受信信号強度が最大値をとる角 The angle at which the received signal strength takes the maximum value when
Θ s のうちその平均値 The average value of Θ s
Θ +1 Θ +1
度 0に対応する方向が前記無線タグ 14の方向として検出された後、本ルーチンが 終了させられる。 After the direction corresponding to the degree 0 is detected as the direction of the wireless tag 14, this routine is terminated.
[0065] また、前記方向検出部 60は、好適には、前記障害物方向検出部 58により障害物 が検出された方向、又は前記障害物方向設定部 59に設定された方向に基づき、例 えばその方向を除外して前記無線タグ 14の方向を検出する。図 12は、斯かる態様 のタグ方向検出制御の要部を説明するフローチャートであり、所定の周期で繰り返し 実行されるものである。この制御において前述した S9の判断が肯定される場合には 、前記障害物方向検出部 58の動作に対応する S15において、前記 I相メモリ部 38及 び Z又は Q相メモリ部 44に記憶された受信信号強度 S 、 S が読み出され、それら 受信信号強度 S 、 S を比較することで障害物の存在する方向が検出 (判定)され る。次に、前記方向検出部 60の動作に対応する S16において、 S15にて検出された 障害物方向、又は前記障害物方向設定部 59に設定された方向から所定角度以上 離れた角度範囲に対応する S 、 S が比較され、最大値をとる受信信号強度に対 Further, the direction detection unit 60 is preferably based on the direction in which the obstacle is detected by the obstacle direction detection unit 58 or the direction set in the obstacle direction setting unit 59, for example. The direction of the wireless tag 14 is detected excluding the direction. FIG. 12 is a flowchart for explaining a main part of the tag direction detection control of such an aspect, and is repeatedly executed at a predetermined cycle. If the determination in S9 described above is affirmed in this control, it is stored in the I-phase memory unit 38 and the Z-phase or Q-phase memory unit 44 in S15 corresponding to the operation of the obstacle direction detection unit 58. The received signal strengths S and S are read, and the received signal strengths S and S are compared to detect (determine) the direction in which the obstacle exists. Next, in S16 corresponding to the operation of the direction detection unit 60, it corresponds to the obstacle direction detected in S15 or an angle range that is more than a predetermined angle away from the direction set in the obstacle direction setting unit 59. S and S are compared and the maximum received signal strength is
Θ Θ +1 Θ Θ +1
応する角度 0に対応する方向が前記無線タグ 14の方向として検出された後、本ル 一チンが終了させられる。 After the direction corresponding to the corresponding angle 0 is detected as the direction of the wireless tag 14, the routine is terminated.
[0066] また、前記方向検出部 60は、好適には、前記第 1の角度に対応する指向性方向と した場合にお!、て受信される受信信号の信号強度 S が所定値以下だった場合には [0066] In addition, the direction detection unit 60 preferably has a signal intensity S of a received signal that is less than or equal to a predetermined value when the directivity direction corresponds to the first angle! in case of
Θ Θ
、その第 1の角度から所定の偏差角度ずらした第 2の角度に対応する受信信号強度 s Θ +1の検出すなわち指向性制御及び前記無線信号の送信及び Z又は受信制御を 省略する。図 7は、斯カる制御について説明する図であり、前記第 1の角度に対応す
る指向性方向とした場合において受信される受信信号の信号強度 s が所定値以下 The detection of the received signal intensity s Θ +1 corresponding to the second angle shifted from the first angle by a predetermined deviation angle, that is, directivity control and transmission and Z or reception control of the radio signal are omitted. FIG. 7 is a diagram for explaining such control and corresponds to the first angle. The signal strength s of the received signal that is received when the directivity direction is
Θ Θ
である角度— 20° 、 30° 、40° については第 2の角度— 21° 、 29° 、39° に対 応する受信信号強度 S の検出が省略されている。また、図 13は、斯かる態様のタ For the angles of 20 °, 30 °, and 40 °, detection of the received signal strength S corresponding to the second angles of 21 °, 29 °, and 39 ° is omitted. In addition, FIG.
Θ +1 Θ +1
グ方向検出制御の要部を説明するフローチャートであり、所定の周期で繰り返し実行 されるものである。この制御では、前述した S6の処理〖こ続く S17〖こおいて、その時点 における角度 Θに対応して前記 I相メモリ部 38及び Z又は Q相メモリ部 44に記憶さ れた受信信号強度 S が読み出され、その受信信号強度 S が所定値以上であるか 5 is a flowchart for explaining a main part of the direction detection control, and is repeatedly executed at a predetermined cycle. In this control, the received signal strength S stored in the I-phase memory unit 38 and Z or the Q-phase memory unit 44 corresponding to the angle Θ at that time in S17 after the processing of S6 described above. Is read and the received signal strength S is greater than or equal to the specified value
Θ Θ Θ Θ
否かが判断される。この S17の判断が肯定される場合には、前述した S7以下の処理 が実行される力 S17の判断が否定される場合には、前述した S9以下の処理が実行 される。そして、その S9の判断が肯定される場合には、前記方向検出部 60の動作に 対応する S18において、前記 I相メモリ部 38及び Z又は Q相メモリ部 44に記憶された 受信信号強度 S 、 S が読み出され、それら受信信号強度 S 、 S の比較により前 It is determined whether or not. When the determination at S17 is affirmed, the force at which the above-described processing after S7 is executed. When the determination at S17 is negative, the processing at S9 and below is executed. If the determination of S9 is affirmative, the received signal strength S stored in the I-phase memory unit 38 and the Z-phase memory unit 44 in S18 corresponding to the operation of the direction detection unit 60, S is read and the received signal strengths S and S
θ θ +1 θ Θ +1 θ θ +1 θ Θ +1
記無線タグ 14の方向が検出された後、本ルーチンが終了させられる。 After the direction of the wireless tag 14 is detected, this routine is terminated.
[0067] また、前記方向検出部 60は、好適には、前記送信信号の搬送波すなわち前記搬 送波発生部 20により発生させられる搬送波の周波数を変化させ、各周波数に対応し て受信される受信信号を比較することで前記無線タグ 14の方向を検出する。図 14は 、斯カる態様のタグ方向検出制御の要部を説明するフローチャートであり、所定の周 期で繰り返し実行されるものである。この制御では、先ず、 S 19において、前記搬送 波発生部 20により発生させられる搬送波の周波数設定値 f力 ¾とされた後、 S1以下 [0067] Further, the direction detection unit 60 preferably changes the frequency of the carrier wave of the transmission signal, that is, the frequency of the carrier wave generated by the carrier wave generation unit 20, and receives the signal corresponding to each frequency. The direction of the wireless tag 14 is detected by comparing the signals. FIG. 14 is a flowchart for explaining a main part of the tag direction detection control of such a mode, which is repeatedly executed in a predetermined cycle. In this control, first, in S 19, the frequency set value f of the carrier wave generated by the carrier wave generator 20 is set to f ¾ and then S 1 or less.
1 1
の処理が実行される。また、前述した S9の判断が肯定される場合には、 S20におい て、前記搬送波発生部 20により発生させられる搬送波の周波数設定値 fが f である end か否かが判断される。この S20の判断が否定される場合には、 S21において、周波 数設定値 fに Δ ίが加算された後、 S1以下の処理が再び実行される力 S20の判断 が肯定される場合には、前記方向検出部 60の動作に対応する S22において、前記 I 相メモリ部 38及び Ζ又は Q相メモリ部 44に記憶された受信信号強度 S 、 S が読 The process is executed. If the determination in S9 described above is affirmed, it is determined in S20 whether or not the frequency set value f of the carrier wave generated by the carrier wave generation unit 20 is f. If the determination at S20 is negative, the power at which S1 and subsequent processing is executed again after S∆ is added to the frequency set value f at S21. In S22 corresponding to the operation of the direction detection unit 60, the received signal strengths S and S stored in the I-phase memory unit 38 and the Ζ or Q-phase memory unit 44 are read.
θ Θ +1 み出され、それら受信信号強度 S 、 S の比較により前記無線タグ 14の方向が検 θ Θ +1 is extracted, and the direction of the wireless tag 14 is detected by comparing the received signal strengths S and S.
θ Θ +1 θ Θ +1
出された後、本ルーチンが終了させられる。 After being issued, this routine is terminated.
[0068] このように、本実施例によれば、無線端末である前記無線タグ 14への無線信号を
送信するため及び Z又はその無線タグ 14からの無線信号を受信するための、複数 のアンテナ素子 26により構成されるアレイアンテナ 16と、それら複数のアンテナ素子 26それぞれに対応する位相を制御することで前記アレイアンテナ 16の送信指向性 及び Z又は受信指向性を制御する指向性制御部 54 (S2及び S7)と、その指向性制 御部 54により前記アレイアンテナ 16の送信指向性及び Z又は受信指向性を第 1の 角度に対応する指向性方向とした場合において受信される受信信号と、その第 1の 角度力 所定の偏差角度ずらした第 2の角度に対応する指向性方向とした場合にお いて受信される受信信号とを、比較することで前記無線タグ 14の方向を検出する方 向検出咅 60 (S11、 S12、 S13、 S14、 S16、 S18、 S22)とを、備えたものであること から、前記受信信号を比較してマルチパスの影響が少ない角度に対応する指向性 方向における受信結果を用いることで、前記無線タグ 14の方向を好適に検出するこ とができる。すなわち、マルチパスの影響を軽減して好適な方向検出を実現する方 向検出装置を提供することができる。 Thus, according to the present embodiment, a wireless signal to the wireless tag 14 that is a wireless terminal is transmitted. By controlling the phase corresponding to each of the plurality of antenna elements 26 and the array antenna 16 composed of a plurality of antenna elements 26 for transmitting and for receiving radio signals from Z or its radio tag 14 A directivity control unit 54 (S2 and S7) that controls the transmission directivity and Z or reception directivity of the array antenna 16, and the directivity control unit 54 control the transmission directivity and Z or reception directivity of the array antenna 16. The received signal received when the directivity corresponding to the first angle is set to the directivity direction corresponding to the second angle shifted by a predetermined deviation angle. And a direction detection rod 60 (S11, S12, S13, S14, S16, S18, S22) for detecting the direction of the wireless tag 14 by comparing the received signal with the received signal. From the said reception No. By using the reception result in the directivity direction corresponding to the angle is less affected multipath by comparing, it said can and preferably detect child the direction of the wireless tag 14. That is, it is possible to provide a direction detection device that reduces the influence of multipath and realizes suitable direction detection.
[0069] また、前記アレイアンテナ 16により受信される受信信号の信号強度を検出する信号 強度検出部 56 (S3及び S8)を備え、前記方向検出部 60は、その信号強度検出部 により検出される信号強度に応じて前記無線タグ 14の方向を検出するものであるた め、実用的な態様で前記無線タグ 14の方向を検出することができる。 [0069] Further, a signal strength detection unit 56 (S3 and S8) for detecting the signal strength of the received signal received by the array antenna 16 is provided, and the direction detection unit 60 is detected by the signal strength detection unit. Since the direction of the wireless tag 14 is detected according to the signal strength, the direction of the wireless tag 14 can be detected in a practical manner.
[0070] また、前記方向検出部 60は、前記第 1の角度を所定角度ずつ段階的に変化させ つつその第 1の角度に対応する指向性方向とした場合において受信される受信信号 又はその信号強度と、前記第 2の角度に対応する指向性方向とした場合において受 信される受信信号又はその信号強度とを、記憶装置である前記 I相メモリ部 38及び Z又は Q相メモリ部 44に記憶し、その記憶装置に記憶された受信信号又はその信号 強度を比較することで前記無線タグ 14の方向を検出するものであるため、マルチパ スの影響が少ない角度に対応する指向性方向を実用的な態様で判定することができ [0070] Further, the direction detection unit 60 receives the received signal when the first angle is changed stepwise by a predetermined angle and the directivity direction corresponding to the first angle is received, or the signal thereof The intensity and the received signal received in the direction of directivity corresponding to the second angle or its signal intensity are stored in the I-phase memory unit 38 and Z or Q-phase memory unit 44 that are storage devices. Since the direction of the wireless tag 14 is detected by storing and comparing the received signal stored in the storage device or its signal strength, a directivity direction corresponding to an angle with less influence of multipath is practically used. Can be determined in a specific manner
、前記無線タグ 14の方向を好適に検出することができる。 The direction of the wireless tag 14 can be detected suitably.
[0071] また、前記偏差角度は、前記第 1の角度の段階的な変化分である所定角度の 1Z1 0以上 1Z5以下であるため、前記アレイアンテナ 16の指向性方向を前記所定角度 に比べて十分に小さい偏差角度だけずらして各指向性方向に対応する受信信号を
比較することで、マルチパスの影響が少ない角度に対応する指向性方向を判定する ことができ、前記無線タグ 14の方向を好適に検出することができる。 [0071] Further, since the deviation angle is not less than 1Z10 and not more than 1Z5 of a predetermined angle that is a step change of the first angle, the directivity direction of the array antenna 16 is compared with the predetermined angle. The received signal corresponding to each directivity direction is shifted by a sufficiently small deviation angle. By comparing, it is possible to determine the directivity direction corresponding to the angle with less influence of the multipath, and the direction of the wireless tag 14 can be suitably detected.
[0072] また、前記偏差角度は、 1乃至 2° の範囲内であるため、前記アレイアンテナ 16の 指向性方向を 1乃至 2° の範囲内でずらして各指向性方向に対応する受信信号を 比較することで、マルチパスの影響が少ない角度に対応する指向性方向を判定する ことができ、前記無線タグ 14の方向を好適に検出することができる。 [0072] Further, since the deviation angle is in the range of 1 to 2 °, the directivity direction of the array antenna 16 is shifted within the range of 1 to 2 °, and the received signal corresponding to each directivity direction is changed. By comparing, it is possible to determine the directivity direction corresponding to the angle with less influence of the multipath, and the direction of the wireless tag 14 can be suitably detected.
[0073] また、前記偏差角度は、前記無線タグ 14の方向検出における許容誤差角度以下 であるため、前記アレイアンテナ 16の指向性方向を方向検出における許容誤差角 度以下の範囲内でずらして各指向性方向に対応する受信信号を比較することで、マ ルチパスの影響が少ない角度に対応する指向性方向を判定することができ、前記無 線タグ 14の方向を好適に検出することができる。 [0073] Further, since the deviation angle is equal to or smaller than the allowable error angle in the direction detection of the wireless tag 14, each directivity direction of the array antenna 16 is shifted within a range equal to or smaller than the allowable error angle in the direction detection. By comparing the received signals corresponding to the directivity direction, the directivity direction corresponding to the angle with less influence of the multipath can be determined, and the direction of the radio tag 14 can be detected suitably.
[0074] また、前記方向検出部 60は、先ず、前記第 1の角度を所定角度ずつ段階的に変 化させつつ前記指向性制御部 54により前記アレイアンテナ 16の送信指向性及び Z 又は受信指向性をそれぞれの第 1の角度に対応する指向性方向とした場合におい て受信される受信信号又はその信号強度を前記 I相メモリ部 38及び Z又は Q相メモ リ部 44に記憶し、次に、前記第 1の角度を所定角度ずつ段階的に変化させつつ前 記指向性制御部 54により前記アレイアンテナ 16の送信指向性及び Z又は受信指向 性をそれぞれの第 1の角度力 所定の偏差角度ずらした第 2の角度に対応する指向 性方向とした場合において受信される受信信号又はその信号強度を前記 I相メモリ 部 38及び Z又は Q相メモリ部 44に記憶し、その I相メモリ部 38及び Z又は Q相メモリ 部 44に記憶された受信信号又はその信号強度を比較することで前記無線タグ 14の 方向を検出するものであるため、マルチパスの影響が少な 、角度に対応する指向性 方向を実用的な態様で判定することができ、前記無線タグ 14の方向を好適に検出す ることがでさる。 [0074] Further, the direction detection unit 60 first changes the first directivity stepwise by a predetermined angle step by step while the directivity control unit 54 performs transmission directivity and Z or reception directivity of the array antenna 16. Stored in the I-phase memory unit 38 and Z or Q-phase memory unit 44, and the received signal or signal strength received when the directivity is set to the directivity direction corresponding to each first angle. The directivity control unit 54 changes the transmission directivity and Z or reception directivity of the array antenna 16 to the respective first angular forces while changing the first angle step by step by a predetermined angle. The received signal or its signal strength received in the direction of directivity corresponding to the shifted second angle is stored in the I-phase memory unit 38 and Z or Q-phase memory unit 44, and the I-phase memory unit 38 And Z or Q phase memory Since the direction of the wireless tag 14 is detected by comparing the received signal or the signal strength thereof, the directivity direction corresponding to the angle can be determined in a practical manner with little multipath effect. It is possible to detect the direction of the wireless tag 14 suitably.
[0075] また、前記方向検出部 60は、前記第 1の角度に対応する指向性方向とした場合に おいて受信される受信信号の信号強度が所定値以下だった場合には、その第 1の 角度力 所定の偏差角度ずらした第 2の角度に対応する指向性制御及び前記無線 信号の送信及び Z又は受信制御を行わな 、ものであるため、障害物が存在する等
の理由で好適な通信を行 、得な 、方向にっ 、て第 2の角度に対応する制御を省くこ とで、前記無線タグ 14の方向検出に要する時間を短縮することができる。 [0075] Further, the direction detection unit 60, when the signal strength of the received signal received when the directivity direction corresponds to the first angle is less than or equal to a predetermined value, Since there is no directivity control corresponding to the second angle shifted by a predetermined deviation angle and transmission and Z or reception control of the wireless signal, there is an obstacle, etc. For this reason, it is possible to shorten the time required for detecting the direction of the wireless tag 14 by performing suitable communication and omitting the control corresponding to the second angle according to the direction.
[0076] また、前記方向検出部 60 (S 11)は、前記 I相メモリ部 38及び Z又は Q相メモリ部 44 に記憶された各受信信号について前記信号強度検出部 56により検出される検出結 果を一通り比較し、その検出結果が最大値をとる送信指向性及び Z又は受信指向 性に対応する方向を前記無線タグ 14の方向として検出するものであるため、実用的 な態様で前記無線タグ 14の方向を検出することができる。 Further, the direction detection unit 60 (S 11) detects the detection result detected by the signal intensity detection unit 56 for each received signal stored in the I-phase memory unit 38 and the Z-phase or Q-phase memory unit 44. And the direction corresponding to the transmission directivity and Z or the reception directivity at which the detection result has the maximum value is detected as the direction of the wireless tag 14, so that the wireless tag 14 can be used in a practical manner. The direction of the tag 14 can be detected.
[0077] また、前記方向検出部 60 (S12)は、前記 I相メモリ部 38及び Z又は Q相メモリ部 44 に記憶された各受信信号について前記信号強度検出部 56により検出される検出結 果を比較し、その検出結果が前記第 1の角度に対応する指向性方向及び第 2の角 度に対応する指向性方向の何れにおいても所定の閾値以上となる送信指向性及び Z又は受信指向性に対応する方向を前記無線タグ 14の方向として検出するもので あるため、実用的な態様で前記無線タグ 14の方向を検出することができる。 Further, the direction detection unit 60 (S12) detects the detection result detected by the signal intensity detection unit 56 for each received signal stored in the I-phase memory unit 38 and the Z-phase or Q-phase memory unit 44. And the transmission directivity and Z or reception directivity in which the detection result is equal to or greater than a predetermined threshold in both the directivity direction corresponding to the first angle and the directivity direction corresponding to the second angle. Since the direction corresponding to is detected as the direction of the wireless tag 14, the direction of the wireless tag 14 can be detected in a practical manner.
[0078] また、前記方向検出部 60 (S13)は、前記 I相メモリ部 38及び Z又は Q相メモリ部 44 に記憶された各受信信号について前記信号強度検出部 56により検出される検出結 果を比較し、前記第 1の角度に対応する指向性方向の検出結果と第 2の角度に対応 する指向性方向の検出結果との差が最も小さい角度に対応する方向を前記無線タ グ 14の方向として検出するものであるため、実用的な態様で前記無線タグ 14の方向 を検出することができる。 Further, the direction detection unit 60 (S13) detects the detection result detected by the signal strength detection unit 56 for each received signal stored in the I-phase memory unit 38 and the Z-phase or Q-phase memory unit 44. And the direction corresponding to the angle with the smallest difference between the detection result of the directivity direction corresponding to the first angle and the detection result of the directivity direction corresponding to the second angle is Since the direction is detected, the direction of the wireless tag 14 can be detected in a practical manner.
[0079] また、前記方向検出部 60 (S 14)は、前記 I相メモリ部 38及び Z又は Q相メモリ部 44 に記憶された各受信信号について前記第 1の角度に対応する指向性方向及び第 2 の角度に対応する指向性方向それぞれに関して前記信号強度検出部 56により検出 される検出結果を平均し、その平均の大きな角度に対応する指向性方向において前 記検出結果が最大値をとる送信指向性及び Z又は受信指向性に対応する方向を前 記無線タグ 14の方向として検出するものであるため、実用的な態様で前記無線タグ 14の方向を検出することができる。 [0079] Further, the direction detection unit 60 (S14) has a directivity direction corresponding to the first angle and each received signal stored in the I-phase memory unit 38 and the Z-phase or Q-phase memory unit 44. The detection results detected by the signal intensity detection unit 56 for each of the directivity directions corresponding to the second angle are averaged, and the transmission result having the maximum detection value in the directivity direction corresponding to the large average angle is transmitted. Since the direction corresponding to the directivity and Z or reception directivity is detected as the direction of the wireless tag 14, the direction of the wireless tag 14 can be detected in a practical manner.
[0080] また、前記 I相メモリ部 38及び Z又は Q相メモリ部 44に記憶された各受信信号又は 信号強度を比較することで障害物の存在する方向を検出する障害物方向検出部 58
(S15)を備え、前記方向検出部 60 (S16)は、その障害物方向検出部 58により障害 物が検出された方向、又は前記障害物方向設定部 59に設定された方向を除外して 前記無線タグ 14の方向を検出するものであるため、マルチパス発生の原因となる障 害物が存在する方向を避けることで、前記無線タグ 14の方向を好適に検出すること ができる。 In addition, an obstacle direction detection unit 58 that detects the direction in which an obstacle exists by comparing the received signals or signal strengths stored in the I-phase memory unit 38 and the Z-phase or Q-phase memory unit 44. (S15), and the direction detection unit 60 (S16) excludes the direction in which the obstacle is detected by the obstacle direction detection unit 58 or the direction set in the obstacle direction setting unit 59. Since the direction of the wireless tag 14 is detected, the direction of the wireless tag 14 can be suitably detected by avoiding the direction in which an obstacle that causes multipath occurs.
[0081] また、前記方向検出装置は、検出対象である無線タグ 14に向けて所定の送信信号 を送信すると共に、その送信信号に応答して前記無線タグ 14から返信される返信信 号を受信することで前記無線タグ 14の方向を検出する無線タグ通信装置 (無線タグ 方向検出装置) 12であるため、マルチパスの影響を軽減して好適な無線タグ 14の方 向検出を実現する無線タグ通信装置 12を提供することができる。 Further, the direction detection device transmits a predetermined transmission signal toward the detection target wireless tag 14 and receives a return signal returned from the wireless tag 14 in response to the transmission signal. Thus, the wireless tag communication device (wireless tag direction detection device) 12 that detects the direction of the wireless tag 14, the wireless tag that realizes the preferred direction detection of the wireless tag 14 by reducing the influence of multipath. A communication device 12 can be provided.
[0082] また、前記方向検出部 60 (S22)は、前記送信信号の搬送波の周波数を変化させ 、各周波数に対応して受信される受信信号を比較することで前記無線タグ 14の方向 を検出するものであるため、複数の搬送波周波数それぞれにおける各指向性方向に 対応して受信される受信信号を比較してマルチパスの影響が少ない搬送波周波数 による受信結果を用いることで、前記無線タグ 14の方向を更に好適に検出すること ができる。 Further, the direction detection unit 60 (S22) detects the direction of the wireless tag 14 by changing the frequency of the carrier wave of the transmission signal and comparing the received signals received corresponding to the respective frequencies. Therefore, by comparing the received signals received corresponding to the respective directivity directions in each of the plurality of carrier frequencies, and using the reception result with the carrier frequency with less influence of the multipath, the wireless tag 14 The direction can be detected more suitably.
[0083] 以上、本第 1発明の好適な実施例を図面に基づいて詳細に説明したが、本第 1発 明はこれに限定されるものではなぐ更に別の態様においても実施される。 As described above, the preferred embodiment of the first invention has been described in detail with reference to the drawings. However, the first invention is not limited to this, and may be implemented in still another mode.
[0084] 例えば、前述の実施例にお!、て、前記指向性制御部 54、信号強度検出部 56、障 害物方向検出部 58、及び方向検出部 60等は、何れも個別に設けられたものであつ たが、本第 1発明はこれに限定されるものではなぐそれらと同等の制御機能が CPU 、 ROM, RAM等を含んでディジタル信号処理を実行する DSP (Digital Signal Proce ssor)等に機能的に備えられたものであっても構わない。また、それら制御装置による 制御は、ディジタル信号処理であるとアナログ信号処理であるとを問わな 、。 For example, the directivity control unit 54, the signal intensity detection unit 56, the obstacle direction detection unit 58, the direction detection unit 60, etc. are all provided individually in the above-described embodiment. However, this first invention is not limited to this, and a control function equivalent to those of DSP (Digital Signal Processor) that executes digital signal processing including CPU, ROM, RAM, etc. It may be provided functionally. Regardless of whether the control by these control devices is digital signal processing or analog signal processing.
[0085] また、前述の実施例において、前記無線タグ通信装置 12に備えられたアンテナ素 子 26は、何れもダイポールアンテナ等の直線状アンテナ素子であり、それら複数本 の直線状アンテナ素子 26から複数組のアレイアンテナ 16が構成されるものであった 力 例えばパッチアンテナ等の平板状 (平面)アンテナ素子力もアレイアンテナが構
成されるものであってもよぐ斯カるアンテナを備えた通信装置にも本第 1発明は好 適に適用され得る。 In the above-described embodiment, each of the antenna elements 26 provided in the RFID tag communication apparatus 12 is a linear antenna element such as a dipole antenna, and the plurality of linear antenna elements 26 are used. Force that consisted of multiple sets of array antennas 16 For example, the antenna power of a flat (planar) antenna element such as a patch antenna The first invention can be suitably applied to a communication apparatus having such an antenna, even if it is configured.
[0086] また、前述の実施例では、前記第 1の角度毎にその第 1の角度力 所定の偏差角 度ずらした単一の第 2の角度に対応する指向性方向とした場合において受信される 受信信号を検出し、その第 2の角度に対応する受信信号と第 1の角度に対応する受 信信号とを比較することで前記無線タグ 14の方向を検出する態様について説明した 力 例えば、前記第 1の角度が Θである場合、その角度 Θ ± 1を前記第 2の角度とす るといったように、前記第 1の角度毎にその第 1の角度力も所定の偏差角度ずらした 複数の第 2の角度に対応する指向性方向とした場合において受信される受信信号を 検出し、それら複数の第 2の角度に対応する受信信号と第 1の角度に対応する受信 信号とを比較することで前記無線タグ 14の方向を検出するものであってもよい。この ようにすれば、マルチパスの影響を可及的に軽減して更に好適な方向検出を実現す ることがでさる。 In the above-described embodiment, the first angular force is received for each first angle when the directivity direction corresponds to a single second angle shifted by a predetermined deviation angle. For example, the power of detecting the direction of the wireless tag 14 by detecting the received signal and comparing the received signal corresponding to the second angle with the received signal corresponding to the first angle. When the first angle is Θ, the first angular force is also shifted by a predetermined deviation angle for each first angle, such that the angle Θ ± 1 is the second angle. Detecting the received signal when the directionality corresponds to the second angle, and comparing the received signal corresponding to the plurality of second angles with the received signal corresponding to the first angle The direction of the wireless tag 14 may be detected. In this way, it is possible to reduce the influence of multipath as much as possible and realize more suitable direction detection.
[0087] また、前述の実施例では、前記無線タグ 14に向けて送信信号を送信すると共に、 その送信信号に応じてその無線タグ 14から返信される返信信号を受信するために 用 、られる送受信共用のアンテナ素子 26を有する送受信共用のアレイアンテナ 16 を備えた無線タグ通信装置 12に本第 1発明が適用された例について説明したが、前 記送信信号を送信するための送信アンテナ及び受信信号を受信するための受信ァ ンテナを別々に備えた無線タグ通信装置にも本第 1発明は好適に適用される。 Further, in the above-described embodiment, the transmission / reception used for transmitting a transmission signal toward the wireless tag 14 and receiving a return signal returned from the wireless tag 14 in response to the transmission signal. Although the example in which the first invention is applied to the RFID tag communication device 12 having the shared antenna element 26 having the shared antenna element 26 has been described, the transmission antenna and the received signal for transmitting the transmitted signal are described above. The first invention is also suitably applied to an RFID tag communication apparatus that is separately provided with a receiving antenna for receiving the message.
[0088] また、前述の実施例では、通信対象である無線タグ 14に向けて所定の送信信号を 送信すると共に、その送信信号に応答して前記無線タグ 14から返信される返信信号 を受信することで前記無線タグ 14との間で情報の通信を行う無線タグ通信装置 12に 本第 1発明が適用された例について説明したが、例えば携帯電話機や移動体通信 装置をはじめとする他の無線通信装置における通信端末の方向検出にも本第 1発明 は好適に適用され得る。 In the above-described embodiment, a predetermined transmission signal is transmitted toward the wireless tag 14 that is a communication target, and a reply signal returned from the wireless tag 14 in response to the transmission signal is received. Thus, the example in which the first invention is applied to the RFID tag communication device 12 that communicates information with the RFID tag 14 has been described. However, other wireless communication devices such as a mobile phone and a mobile communication device have been described. The first invention can also be suitably applied to direction detection of a communication terminal in a communication device.
[0089] その他、一々例示はしないが、本第 1発明はその趣旨を逸脱しない範囲内におい て種々の変更が加えられて実施されるものである。 [0089] In addition, although not illustrated one by one, the first invention is implemented with various modifications without departing from the spirit thereof.
[0090] 続いて、本第 2発明の好適な実施例を図面に基づいて詳細に説明する。なお、以
下の説明にお 、て、実施例相互に共通する部分につ!、ては同一の符号をもってそ の説明を省略する。 [0090] Next, a preferred embodiment of the second invention will be described in detail with reference to the drawings. Note that In the following description, parts common to the embodiments are denoted by the same reference numerals and description thereof is omitted.
[0091] 図 15は、本第 2発明の一実施例である無線タグ通信装置 93の構成を説明する図 である。この図 2に示すように、本実施例の無線タグ通信装置 93は、前述した搬送波 発生部 20、搬送波増幅部 22、送受信モジュール 24、アンテナ素子 26、受信信号合 成部 28、可変増幅部 30、ホモダイン検波回路 32、 I相 LPF34、 I相 AZD変換部 36 、 I相メモリ部 38、 Q相 LPF40、 Q相 AZD変換部 42、及び Q相メモリ部 44を備えて いる。また、前記搬送波増幅部 22と送受信モジュール 24aとの間の信号伝達回路を 開閉する送信回路切替部 46aと、前記搬送波増幅部 22と送受信モジュール 24cとの 間の信号伝達回路を開閉する送信回路切替部 46b (以下、送信回路切替部 46aと 特に区別しない場合には単に送信回路切替部 46と称する)と、前記送受信モジユー ル 24aと受信信号合成部 28との間の信号伝達回路を開閉する受信回路切替部 48a と、前記送受信モジュール 24cと受信信号合成部 28との間の信号伝達回路を開閉 する受信回路切替部 48c (以下、受信回路切替部 48aと特に区別しない場合には単 に受信回路切替部 48と称する)とを、備えて構成されている。また、前記無線タグ 14 の方向を検出する方向検出制御を行うために、前述した各制御部に準ずる制御を行 う送信データ生成部 50、指向性制御部 54、信号強度検出部 56、障害物方向検出 部 58、障害物方向設定部 59、及び方向検出部 60を備えている。また、それらにカロ えてアンテナ選択制御部 52を備えて 、る。 FIG. 15 is a diagram for explaining the configuration of a wireless tag communication device 93 according to an embodiment of the second invention. As shown in FIG. 2, the RFID tag communication apparatus 93 according to the present embodiment includes the carrier generation unit 20, the carrier amplification unit 22, the transmission / reception module 24, the antenna element 26, the reception signal synthesis unit 28, and the variable amplification unit 30 described above. A homodyne detection circuit 32, an I-phase LPF 34, an I-phase AZD conversion unit 36, an I-phase memory unit 38, a Q-phase LPF 40, a Q-phase AZD conversion unit 42, and a Q-phase memory unit 44. Also, a transmission circuit switching unit 46a that opens and closes a signal transmission circuit between the carrier wave amplification unit 22 and the transmission / reception module 24a, and a transmission circuit switching that opens and closes a signal transmission circuit between the carrier wave amplification unit 22 and the transmission / reception module 24c. Unit 46b (hereinafter simply referred to as a transmission circuit switching unit 46 unless otherwise distinguished from the transmission circuit switching unit 46a) and a reception circuit that opens and closes a signal transmission circuit between the transmission / reception module 24a and the reception signal synthesis unit 28. A circuit switching unit 48a and a reception circuit switching unit 48c that opens and closes a signal transmission circuit between the transmission / reception module 24c and the reception signal combining unit 28 (hereinafter simply referred to as a reception circuit unless otherwise distinguished from the reception circuit switching unit 48a). (Referred to as switching unit 48). In addition, in order to perform direction detection control for detecting the direction of the wireless tag 14, a transmission data generation unit 50, a directivity control unit 54, a signal intensity detection unit 56, an obstacle that performs control according to each control unit described above A direction detection unit 58, an obstacle direction setting unit 59, and a direction detection unit 60 are provided. In addition, an antenna selection control unit 52 is provided in addition to these.
[0092] 上記アンテナ選択制御部 52は、前記複数のアンテナ素子 26のうち少なくとも 2つ のアンテナ素子 26により信号の送信及び Z又は受信が行われるように、前記送信回 路切替部 46及び Z又は受信回路切替部 48を介して回路を切り替える。本実施例の 無線タグ通信装置 93では、前記複数のアンテナ素子 26により複数組のアレイアンテ ナが選択的に成立させられる。すなわち、前記無線タグ 14への送信信号の送信に 関して、前記送信回路切替部 46aが接続されると共に 46cが開放されることでアンテ ナ素子 26a及び 26bから成るアレイアンテナ 16aが、前記送信回路切替部 46aが開 放されると共に 46cが接続されることでアンテナ素子 26b及び 26cから成るアレイアン テナ 16bが、前記送信回路切替部 46a及び 46cが共に接続されることでアンテナ素
子 26a、 26b、及び 26cから成るアレイアンテナ 16cがそれぞれ成立させられる。また 、前記無線タグ 14からの返信信号の受信に関して、前記受信回路切替部 48aが接 続されると共に 48cが開放されることでアンテナ素子 26a及び 26bから成るアレイアン テナ 16aが、前記受信回路切替部 48aが開放されると共に 48cが接続されることでァ ンテナ素子 26b及び 26cから成るアレイアンテナ 16bが、前記受信回路切替部 48a 及び 48cが共に接続されることでアンテナ素子 26a、 26b、及び 26cから成るアレイァ ンテナ 16cがそれぞれ成立させられる。換言すれば、前記アンテナ選択制御部 52は 、複数組のアレイアンテナ 16a、 16b、 16c (以下、特に区別しない場合には単にァレ イアンテナ 16と称する)のうち何れか 1組のアレイアンテナ 16により選択的に前記無 線タグ 14に対する無線信号が送信及び Z又は受信されるように回路を切り替える。 また、このように本実施例では、上記複数組のアレイアンテナ 16を構成するアンテナ 素子 26のうち、それらアンテナ素子 26の配設幅方向の中央に位置する 1つのアンテ ナ素子 26bは上記複数組のアレイアンテナ 16に共用される。 The antenna selection control unit 52 transmits the transmission circuit switching unit 46, Z, or Z so that the signal is transmitted and Z or received by at least two antenna elements 26 of the plurality of antenna elements 26. The circuit is switched via the receiving circuit switching unit 48. In the RFID tag communication apparatus 93 of this embodiment, a plurality of sets of array antennas are selectively established by the plurality of antenna elements 26. That is, regarding transmission of a transmission signal to the wireless tag 14, the array antenna 16a including the antenna elements 26a and 26b is connected to the transmission circuit by connecting the transmission circuit switching unit 46a and opening 46c. When the switching unit 46a is opened and 46c is connected, the array antenna 16b composed of the antenna elements 26b and 26c is connected to the antenna circuit by connecting the transmission circuit switching units 46a and 46c together. An array antenna 16c consisting of children 26a, 26b and 26c is established. Further, with respect to reception of the reply signal from the wireless tag 14, the receiving circuit switching unit 48a is connected and the array antenna 16a including the antenna elements 26a and 26b is opened by the 48c being opened, so that the receiving circuit switching unit 48a is opened. The array antenna 16b composed of the antenna elements 26b and 26c is connected to the antenna elements 26a, 26b, and 26c by connecting both the receiving circuit switching units 48a and 48c. Each of the array antennas 16c is formed. In other words, the antenna selection control unit 52 is one of a plurality of sets of array antennas 16a, 16b, 16c (hereinafter simply referred to as array antenna 16 unless otherwise specified). To selectively switch the circuit so that a radio signal for the radio tag 14 is transmitted and Z or received. As described above, in the present embodiment, among the antenna elements 26 constituting the plurality of sets of array antennas 16, one antenna element 26b positioned at the center in the arrangement width direction of the antenna elements 26 is the plurality of sets. Common to array antenna 16
[0093] 前記指向性制御部 54は、上記複数組のアレイアンテナ 16それぞれの送信指向性 及び Z又は受信指向性を制御する。具体的には、各送受信モジュール 24における 送信移相部 62を介してそれぞれ対応するアンテナ素子 26から送信される送信信号 の位相を制御することで、上記複数組のアレイアンテナ 16それぞれの送信指向性を 制御する。また、各送受信モジュール 24における受信移相部 70を介してそれぞれ 対応するアンテナ素子 26により受信される受信信号の位相を制御することで、上記 複数組のアレイアンテナ 16それぞれの受信指向性を制御する。 The directivity control unit 54 controls the transmission directivity and Z or reception directivity of each of the plurality of sets of array antennas 16. Specifically, the transmission directivity of each of the plurality of array antennas 16 is controlled by controlling the phase of the transmission signal transmitted from the corresponding antenna element 26 via the transmission phase shifter 62 in each transmission / reception module 24. To control. Further, the reception directivity of each of the plurality of sets of array antennas 16 is controlled by controlling the phase of the reception signal received by the corresponding antenna element 26 via the reception phase shift unit 70 in each transmission / reception module 24. .
[0094] 前記信号強度検出部 56は、前記複数^ &のアレイアンテナ 16それぞれに対応する 受信信号の信号強度を検出する。具体的には、前記 I相メモリ部 38に記憶された I相 信号及び Q相メモリ部 44に記憶された Q相信号を読み出し、それら I相信号及び Q相 信号それぞれの二乗の和の平方根を算出すること等によりそれら I相信号及び Q相 信号に相当する受信信号の信号強度を検出する。 The signal strength detector 56 detects the signal strength of the received signal corresponding to each of the plurality of array antennas 16. Specifically, the I-phase signal stored in the I-phase memory unit 38 and the Q-phase signal stored in the Q-phase memory unit 44 are read, and the square root of the sum of the squares of the I-phase signal and the Q-phase signal is calculated. The signal strength of the received signal corresponding to the I-phase signal and Q-phase signal is detected by calculation.
[0095] 前記障害物方向検出部 58は、前記複数^ &のアレイアンテナ 16それぞれにより送 信あるいは受信を行った結果、受信される受信信号を比較することで障害物の存在 する方向を検出する。この検出は、好適には、前記信号強度検出部 56の検出結果
に基づいて行われる。すなわち、前記障害物方向検出部 58は、前記複数組のアレイ アンテナ 16それぞれにより送信あるいは受信を行った結果、受信される受信信号の 信号強度が極小又は極大となる方向を上記障害物が存在する方向として検出する。 また前記障害物方向設定部 59は障害物の方向が既知である場合にその方向を設 定する。 The obstacle direction detection unit 58 detects the direction in which the obstacle exists by comparing the received signals received as a result of transmission or reception by each of the plurality of array antennas 16. . This detection is preferably performed by the detection result of the signal intensity detection unit 56. Based on. That is, the obstacle direction detection unit 58 has the obstacle in a direction in which the signal intensity of the received signal received is minimized or maximized as a result of transmission or reception by each of the plurality of sets of array antennas 16. Detect as direction. The obstacle direction setting unit 59 sets the direction of the obstacle when the direction is known.
[0096] 前記方向検出部 60は、前記複数^ &のアレイアンテナ 16それぞれによる送信及び Z又は受信の結果、受信される受信信号を比較することで前記無線タグ 14の存在 する方向を検出する。すなわち、前記アンテナ選択制御部 52により選択的に成立さ せられるアレイアンテナ 16のそれぞれについて前記無線タグ 14に対する無線信号 の送信及び Z又は受信を行 ヽ、その無線信号に対応して受信される受信信号を比 較することで前記無線タグ 14の存在する方向を検出する。 The direction detection unit 60 detects the direction in which the wireless tag 14 exists by comparing received signals received as a result of transmission and Z or reception by the plurality of array antennas 16. That is, for each of the array antennas 16 that is selectively established by the antenna selection control unit 52, transmission and Z or reception of a wireless signal to the wireless tag 14 are performed, and reception that is received corresponding to the wireless signal is performed. The direction in which the wireless tag 14 exists is detected by comparing the signals.
[0097] 本実施例の無線タグ通信装置 93に備えられた複数のアンテナ素子 26は、好適に は、何れもダイポールアンテナ等の直線状アンテナ素子であり、それら複数の直線状 アンテナ素子 26が同一平面内に互いに平行を成すように且つ等間隔で配設された ものである。また、好適には、前記アレイアンテナ 16を構成する複数本の直線状アン テナ素子 26のうち、相互に最も離れて配設された直線状アンテナ素子 26相互間の 距離すなわちアンテナ素子 26a及び 26c相互間の距離は、前記搬送波発生部 20に より発生させられる搬送波の波長以下とされている。そして、前述したように、互いに 平行を成すように配設された 3本の直線状アンテナ素子 26のうち相互に隣接する 2 本ずつの直線状アンテナ素子 26a及び 26b、 26b及び 26cから 2組のアレイアンテナ 16a、 16bがそれぞれ構成される。また、特に図示しないが、前述した図 15の構成に 加えて前記搬送波増幅部 22と送受信モジュール 24bとの間の信号伝達回路を開閉 する送信回路切替部 46bと、前記送受信モジュール 24bと受信信号合成部 28との 間の信号伝達回路を開閉する受信回路切替部 48bとを設けることで、相互に最も離 れて配設された 2本の直線状アンテナ素子 26a及び 26cからアレイアンテナ 16を構 成することちでさる。 [0097] The plurality of antenna elements 26 provided in the RFID tag communication apparatus 93 of the present embodiment are preferably all linear antenna elements such as a dipole antenna, and the plurality of linear antenna elements 26 are the same. They are arranged in a plane so as to be parallel to each other and at equal intervals. Preferably, among the plurality of linear antenna elements 26 constituting the array antenna 16, the distance between the linear antenna elements 26 arranged farthest from each other, that is, the antenna elements 26a and 26c The distance between them is equal to or less than the wavelength of the carrier wave generated by the carrier wave generator 20. As described above, two sets of two linear antenna elements 26a and 26b, 26b and 26c adjacent to each other out of the three linear antenna elements 26 arranged so as to be parallel to each other. Array antennas 16a and 16b are respectively configured. Although not particularly illustrated, in addition to the configuration of FIG. 15 described above, a transmission circuit switching unit 46b that opens and closes a signal transmission circuit between the carrier wave amplification unit 22 and the transmission / reception module 24b, and the transmission / reception module 24b and reception signal synthesis The array antenna 16 is composed of two linear antenna elements 26a and 26c that are arranged farthest from each other by providing a receiving circuit switching unit 48b that opens and closes a signal transmission circuit with the unit 28. I'll do it for you.
[0098] 図 16は、前記無線タグ通信装置 93が適用された無線タグ通信システム 10が室 90 内において運用される場合に発生するマルチパスについて説明する図である。この
図 16に示すように、前記無線タグ通信システム 10が四方に障害物である壁 92を有 する室 90内において運用される場合、その壁 92に起因する反射や回折等により直 接波の経路とは別に所謂マルチパスが発生することが考えられる。図 16では、前記 アンテナ素子 26a及び 26bから成るアレイアンテナ 16aによる直接波及びマルチパス を実線矢印で、前記アンテナ素子 26b及び 26cから成るアレイアンテナ 16bによる直 接波及びマルチパスを破線矢印でそれぞれ示して 、る。このようにマルチパスが発 生した場合、そのマルチパスと直接波とは経路によって異なった位相となるため、そ の直接波経路の信号がマルチパス経路の信号により強められたり、弱められたりする 。また、マルチパスにより直接波の届力ない場所にも電波が届くようになる。図 17及 び図 18は、前記アレイアンテナ 16a、 16bで同様に指向性を変化させていった場合 における受信信号の信号強度の違いを説明する図であり、各指向性方向に応じた受 信信号の信号強度を矢印で示している。これら図 17及び図 18に示すように、障害物 である上記壁 92に対するアレイアンテナ 16の位置を変えることでマルチパスの経路 もまた変化するため、前記アレイアンテナ 16a、 16bの送信指向性及び Z又は受信 指向性を同様に変化させていった場合であってもそれぞれの指向性に応じて受信さ れる受信信号の信号強度は異なってくる。 FIG. 16 is a diagram for explaining multipath that occurs when the RFID tag communication system 10 to which the RFID tag communication apparatus 93 is applied is operated in the room 90. this As shown in FIG. 16, when the RFID tag communication system 10 is operated in a room 90 having walls 92 that are obstacles on all sides, a direct wave path is caused by reflection or diffraction caused by the walls 92. In addition to this, a so-called multipath may occur. In FIG. 16, the direct wave and multipath by the array antenna 16a consisting of the antenna elements 26a and 26b are indicated by solid arrows, and the direct wave and multipath by the array antenna 16b consisting of the antenna elements 26b and 26c are indicated by dashed arrows, respectively. And When a multipath occurs in this way, the multipath and the direct wave have different phases depending on the path, so the signal of the direct wave path is strengthened or weakened by the signal of the multipath path. . In addition, radio waves can reach places where direct waves cannot reach due to multipath. FIG. 17 and FIG. 18 are diagrams for explaining the difference in signal strength of the received signal when the directivity is similarly changed in the array antennas 16a and 16b. The signal strength of the signal is indicated by an arrow. As shown in FIGS. 17 and 18, since the path of the multipath is also changed by changing the position of the array antenna 16 with respect to the wall 92, which is an obstacle, the transmission directivity and Z of the array antennas 16a and 16b are changed. Or, even when the reception directivity is changed in the same way, the signal strength of the received signal varies depending on the directivity.
前記方向検出部 60は、具体的には、前記指向性制御部 54により前記複数組のァ レイアンテナ 16それぞれの送信指向性及び Z又は受信指向性を制御し、各送信指 向性及び Z又は受信指向性に対応して受信される受信信号に対応する前記信号強 度検出部 56の検出結果を比較することで前記無線タグ 14の存在する方向を検出す る。好適には、所定の中心方向を基準として 30° 乃至 30° といったように予め定 められた所定の相対角度範囲に対応して前記指向性制御部 54により前記複数組の アレイアンテナ 16それぞれの送信指向性及び Z又は受信指向性を制御し、各送信 指向性及び Z又は受信指向性に対応して受信される受信信号を比較することで前 記無線タグ 14の方向を検出する。以下、斯カる無線タグ 14の方向検出制御を、図 1 9乃至図 24のフローチャートを用いて説明する。なお、それら図 19乃至図 24のフロ 一チャートに示す制御において、共通するステップは同一の符号を付してその説明 を省略する。
[0100] 前記方向検出部 60は、好適には、前記指向性制御部 54により前記複数組のァレ イアンテナ 16それぞれの送信指向性及び Z又は受信指向性を制御し、各送信指向 性及び Z又は受信指向性に対応して受信される受信信号について前記信号強度検 出部 56により検出される検出結果を一通り比較し、その検出結果が最大値をとる送 信指向性及び Z又は受信指向性に対応する方向を前記無線タグ 14の方向として検 出する。図 19は、斯カる態様のタグ方向検出制御の要部を説明するフローチャート であり、所定の周期で繰り返し実行されるものである。 Specifically, the direction detection unit 60 controls the transmission directivity and Z or reception directivity of each of the plurality of sets of array antennas 16 by the directivity control unit 54, and each transmission directivity and Z or The direction in which the wireless tag 14 exists is detected by comparing the detection results of the signal intensity detection unit 56 corresponding to the received signal received corresponding to the reception directivity. Preferably, each of the plurality of sets of array antennas 16 is transmitted by the directivity control unit 54 corresponding to a predetermined relative angle range such as 30 ° to 30 ° with respect to a predetermined center direction. The direction of the wireless tag 14 is detected by controlling the directivity and Z or reception directivity and comparing the received signals received corresponding to each transmission directivity and Z or reception directivity. Hereinafter, the direction detection control of the wireless tag 14 will be described with reference to the flowcharts of FIGS. In the control shown in the flowcharts of FIGS. 19 to 24, common steps are denoted by the same reference numerals and description thereof is omitted. [0100] Preferably, the direction detection unit 60 controls the transmission directivity and Z or reception directivity of each of the plurality of array antennas 16 by the directivity control unit 54, so that each transmission directivity and Compare the detection results detected by the signal strength detection unit 56 with respect to the received signal received corresponding to Z or reception directivity, and transmit directivity and Z or reception at which the detection result takes the maximum value. The direction corresponding to the directivity is detected as the direction of the wireless tag 14. FIG. 19 is a flowchart for explaining a main part of the tag direction detection control of such a mode, and is repeatedly executed at a predetermined cycle.
[0101] 図 19の制御では、先ず、ステップ(以下、ステップを省略する) S101において、前 記複数組のアレイアンテナ 16から i= l (例えば、 i= lにはアレイアンテナ 16aが、 i= 2にはアレイアンテナ 16bが対応)で指定されるアレイアンテナ 16が選択され、その 選択されたアレイアンテナ 16が構成されるように前記送信回路切替部 46及び Z又 は受信回路切替部 48が切り替えられる。次に、 S 102において、指向性方向を示す 角度 Θが初期値である Θ In the control of FIG. 19, first, in step (hereinafter, step is omitted) S101, from the plurality of array antennas 16 i = l (for example, for i = l, the array antenna 16a becomes i = l The array antenna 16 specified in (2) corresponds to the array antenna 16b), and the transmission circuit switching unit 46 and the Z or reception circuit switching unit 48 are switched so that the selected array antenna 16 is configured. It is done. Next, in S102, the angle Θ indicating the directivity direction is the initial value Θ
startとされ、その角度 Θに応じて前記送信移相部 62及び Z 又は受信移相部 70の設定が行われる。次に、 S103において、検出対象である無線 タグ 14に向けて所定の送信信号を送信すると共に、その送信信号に応答して前記 無線タグ 14から返信される返信信号を受信する送受信処理が行われる。次に、前記 信号強度検出部 56の動作に対応する S104において、 S103の送受信処理により受 信された受信信号の信号強度が検出されると共に、その検出結果 S が前記 I相メモ The transmission phase shift unit 62 and Z or the reception phase shift unit 70 are set according to the angle Θ. Next, in S103, a transmission / reception process is performed in which a predetermined transmission signal is transmitted to the detection target wireless tag 14 and a reply signal returned from the wireless tag 14 in response to the transmission signal is received. . Next, in S104 corresponding to the operation of the signal strength detection unit 56, the signal strength of the received signal received by the transmission / reception processing in S103 is detected, and the detection result S is used as the I-phase memory.
Ϊ Θ Ϊ Θ
リ部 38及び Z又は Q相メモリ部 44に記憶される。次に、 S105において、指向性方向 を示す角度 Θが所定値 Θ であるか否かが判断される。この S 105の判断が否定さ Stored in the memory unit 38 and the Z or Q phase memory unit 44. Next, in S105, it is determined whether or not the angle Θ indicating the directivity direction is a predetermined value Θ. This S 105 judgment is denied
end end
れる場合には、 S106において、指向性方向を示す角度 Θに Δ Θが加算され、その 角度 Θに応じて前記送信移相部 62及び Z又は受信移相部 70の設定が行われた後 、 S103以下の処理が再び実行される力 S105の判断が肯定される場合には、 S10 7において、前記アレイアンテナ 16を指定する iが i である力否かが判断される。この In S106, ΔΘ is added to the angle Θ indicating the directivity direction, and the transmission phase shifter 62 and Z or the reception phase shifter 70 are set according to the angle Θ. When the determination of the force S105 in which the processing from S103 onward is executed again is affirmed, it is determined in S107 whether or not the force for specifying the array antenna 16 is i. this
end end
S107の判断が否定される場合には、 S108において、 iに 1が加算され、その iで指定 されるアレイアンテナ 16が選択されて前記送信回路切替部 46及び Z又は受信回路 切替部 48が切り替えられた後、 S102以下の処理が再び実行される力 S107の判 断が肯定される場合には、前記方向検出部 60の動作に対応する S109において、
前記 I相メモリ部 38及び Z又は Q相メモリ部 44に記憶された受信信号強度 S が全て 比較され、最大値をとる S に対応する Θが前記無線タグ 14の方向として検出された 後、本ルーチンが終了させられる。以上の制御において、 S101及び S108が前記ァ ンテナ選択制御部 52の動作に、 S102及び S106が前記指向性制御部 54の動作に それぞれ対応する。 If the determination in S107 is negative, in S108, 1 is added to i, the array antenna 16 designated by i is selected, and the transmission circuit switching unit 46 and Z or the reception circuit switching unit 48 are switched. If the determination at S107 is affirmative after S102, the process at S102 and subsequent steps is executed again at S109 corresponding to the operation of the direction detection unit 60. The received signal strength S stored in the I-phase memory unit 38 and Z or the Q-phase memory unit 44 are all compared, and after Θ corresponding to S taking the maximum value is detected as the direction of the wireless tag 14, The routine is terminated. In the above control, S101 and S108 correspond to the operation of the antenna selection control unit 52, and S102 and S106 correspond to the operation of the directivity control unit 54, respectively.
[0102] また、前記方向検出部 60は、好適には、前記指向性制御部 54により前記複数組 のアレイアンテナ 16それぞれの送信指向性及び Z又は受信指向性を制御し、各送 信指向性及び Z又は受信指向性に対応して受信される受信信号について前記信号 強度検出部 56により検出される検出結果を比較し、その検出結果が前記複数組の アレイアンテナ 16何れにおいても所定の閾値以上となる送信指向性及び Z又は受 信指向性に対応する方向を前記無線タグ 14の方向として検出する。図 20は、斯かる 態様のタグ方向検出制御の要部を説明するフローチャートであり、所定の周期で繰り 返し実行されるものである。この制御において上述した S 107の判断が肯定される場 合には、前記方向検出部 60の動作に対応する S 110において、前記 I相メモリ部 38 及び Z又は Q相メモリ部 44に記憶された受信信号強度 S が比較され、前記アレイ [0102] In addition, the direction detection unit 60 preferably controls the transmission directivity and Z or reception directivity of each of the plurality of sets of array antennas 16 by the directivity control unit 54, and transmits each transmission directivity. And the detection result detected by the signal intensity detection unit 56 for the received signal corresponding to Z or reception directivity is compared, and the detection result is equal to or greater than a predetermined threshold value in any of the plurality of sets of array antennas 16. The direction corresponding to the transmission directivity and Z or the reception directivity is detected as the direction of the wireless tag 14. FIG. 20 is a flowchart for explaining a main part of the tag direction detection control of such an aspect, and is repeatedly executed at a predetermined cycle. If the determination in S107 described above is affirmed in this control, the data is stored in the I-phase memory unit 38 and the Z-phase memory unit 44 in S110 corresponding to the operation of the direction detection unit 60. The received signal strength S is compared and the array
Ϊ Θ Ϊ Θ
アンテナ 16を指定する i= l〜i の全てについて S が所定の閾値 A以上である角 Designate antenna 16 i = l ~ i for all angles where S is greater than or equal to a predetermined threshold A
end ΐ θ end ΐ θ
度 Θに対応する方向が前記無線タグ 14の方向として検出された後、本ルーチンが 終了させられる。 After the direction corresponding to the angle Θ is detected as the direction of the wireless tag 14, this routine is terminated.
[0103] また、前記方向検出部 60は、好適には、前記指向性制御部 54により前記複数組 のアレイアンテナ 16それぞれの送信指向性及び Ζ又は受信指向性を制御し、各送 信指向性及び Ζ又は受信指向性に対応して受信される受信信号について前記信号 強度検出部 56により検出される検出結果を比較し、前記複数組のアレイアンテナ 16 のうちその検出結果の変動が最も少ないアレイアンテナ 16においてその検出結果が 最大値をとる送信指向性及び Ζ又は受信指向性に対応する方向を前記無線タグ 14 の方向として検出する。図 21は、斯カる態様のタグ方向検出制御の要部を説明する フローチャートであり、所定の周期で繰り返し実行されるものである。この制御におい て前述した S107の判断が肯定される場合には、前記方向検出部 60の動作に対応 する SI 11にお 、て、前記 I相メモリ部 38及び Ζ又は Q相メモリ部 44に記憶された受
信信号強度 S が読み出され、前記アレイアンテナ 16を指定する i= l〜i のそれぞ ίθ end [0103] In addition, the direction detection unit 60 preferably controls the transmission directivity and the trapping or reception directivity of each of the plurality of sets of array antennas 16 by the directivity control unit 54, and each transmission directivity. And the detection results detected by the signal intensity detection unit 56 for received signals received corresponding to Ζ or reception directivity, and the array having the smallest variation in the detection results among the plurality of sets of array antennas 16 The antenna 16 detects the direction of the radio tag 14 as the direction corresponding to the transmission directivity and Ζ or the reception directivity at which the detection result takes the maximum value. FIG. 21 is a flowchart for explaining a main part of the tag direction detection control of such a mode, which is repeatedly executed at a predetermined cycle. In this control, if the determination in S107 described above is affirmed, the data is stored in the I-phase memory unit 38 and the Ζ or Q-phase memory unit 44 in SI 11 corresponding to the operation of the direction detection unit 60. Received The signal strength S is read out, and the array antenna 16 is specified. I = l to i
れについて S の最大値と最小値との差が算出され、その差が最も小さいアレイアン テナ 16において S が最大値をとる角度 0に対応する方向が前記無線タグ 14の方 向として検出された後、本ルーチンが終了させられる。 After the difference between the maximum value and the minimum value of S is calculated, and the direction corresponding to the angle 0 at which S takes the maximum value is detected as the direction of the wireless tag 14 in the array antenna 16 with the smallest difference. This routine is terminated.
[0104] また、前記方向検出部 60は、好適には、前記指向性制御部 54により前記複数組 のアレイアンテナ 16それぞれの送信指向性及び Z又は受信指向性を制御し、各受 信指向性に対応して受信される受信信号について前記信号強度検出部 56により検 出される検出結果を平均し、その平均の最も大きなアレイアンテナ 16において前記 検出結果が最大値をとる送信指向性及び Z又は受信指向性に対応する方向を前記 無線タグの方向として検出する。図 22は、斯カる態様のタグ方向検出制御の要部を 説明するフローチャートであり、所定の周期で繰り返し実行されるものである。この制 御において前述した S107の判断が肯定される場合には、前記方向検出部 60の動 作に対応する S112において、前記 I相メモリ部 38及び Z又は Q相メモリ部 44に記憶 された受信信号強度 S が読み出され、前記アレイアンテナ 16を指定する i= l〜i [0104] In addition, the direction detection unit 60 preferably controls the transmission directivity and Z or reception directivity of each of the plurality of sets of array antennas 16 by the directivity control unit 54, and each reception directivity. The detection results detected by the signal intensity detection unit 56 are averaged for the received signals received corresponding to the transmission directivity and Z or reception at which the detection result has the maximum value in the array antenna 16 having the largest average. A direction corresponding to directivity is detected as the direction of the wireless tag. FIG. 22 is a flowchart for explaining a main part of the tag direction detection control of such a mode, which is repeatedly executed at a predetermined cycle. If the determination in S107 described above is affirmed in this control, the reception stored in the I-phase memory unit 38 and Z or Q-phase memory unit 44 in S112 corresponding to the operation of the direction detection unit 60. The signal strength S is read and designates the array antenna 16 i = l to i
ί θ end のそれぞれについて S の平均値 (相加平均)が算出され、その平均が最も大きなァ レイアンテナ 16において S が最大値をとる角度 0に対応する方向が前記無線タグ 14の方向として検出された後、本ルーチンが終了させられる。 The average value of S (arithmetic average) is calculated for each of ίθ end, and the direction corresponding to the angle 0 at which S takes the maximum value is detected as the direction of the wireless tag 14 in the array antenna 16 having the largest average. Then, this routine is terminated.
[0105] また、前記方向検出部 60は、好適には、前記障害物方向検出部 58により障害物 が検出された方向、又は前記障害物方向設定部 59に設定された方向に基づき、例 えばその方向を除外して前記無線タグ 14の方向を検出する。図 23は、斯かる態様 のタグ方向検出制御の要部を説明するフローチャートであり、所定の周期で繰り返し 実行されるものである。この制御において前述した S 107の判断が肯定される場合に は、前記障害物方向検出部 58の動作に対応する S113において、前記 I相メモリ部 3 8及び Z又は Q相メモリ部 44に記憶された受信信号強度 S が読み出され、それら受 信信号強度 S を比較することで障害物の存在する方向が検出 (判定)される。次に、 前記方向検出部 60の動作に対応する S114において、 S113にて検出された障害 物方向、又は前記障害物方向設定部 59に設定された方向から所定角度以上離れ た角度範囲において S が最大値をとる角度 0に対応する方向が前記無線タグ 14
の方向として検出された後、本ルーチンが終了させられる。 Further, the direction detection unit 60 is preferably based on the direction in which the obstacle is detected by the obstacle direction detection unit 58 or the direction set in the obstacle direction setting unit 59, for example. The direction of the wireless tag 14 is detected excluding the direction. FIG. 23 is a flowchart for explaining a main part of the tag direction detection control of such an aspect, and is repeatedly executed at a predetermined cycle. If the determination in S107 described above is affirmed in this control, it is stored in the I-phase memory unit 38 and the Z-phase or Q-phase memory unit 44 in S113 corresponding to the operation of the obstacle direction detection unit 58. The received signal strength S is read, and the received signal strength S is compared to detect (determine) the direction in which the obstacle exists. Next, in S114 corresponding to the operation of the direction detection unit 60, S is detected in the obstacle range detected in S113 or in an angle range that is more than a predetermined angle away from the direction set in the obstacle direction setting unit 59. The direction corresponding to the angle 0 taking the maximum value is the wireless tag 14 After the direction is detected, this routine is terminated.
[0106] また、前記方向検出部 60は、好適には、前記送信信号の搬送波すなわち前記搬 送波発生部 20により発生させられる搬送波の周波数を変化させ、各周波数に対応し て受信される受信信号を比較することで前記無線タグ 14の方向を検出する。図 24は 、斯カる態様のタグ方向検出制御の要部を説明するフローチャートであり、所定の周 期で繰り返し実行されるものである。この制御では、先ず、 S 115において、前記搬送 波発生部 20により発生させられる搬送波の周波数設定値 f力 ¾とされた後、 S101以 [0106] Further, the direction detection unit 60 preferably changes the frequency of the carrier wave of the transmission signal, that is, the frequency of the carrier wave generated by the carrier wave generation unit 20, and is received corresponding to each frequency. The direction of the wireless tag 14 is detected by comparing the signals. FIG. 24 is a flowchart for explaining a main part of the tag direction detection control in this mode, and is repeatedly executed in a predetermined cycle. In this control, first, in S115, the frequency set value f of the carrier wave generated by the carrier wave generating unit 20 is set to f ¾ and then S101 and thereafter.
1 1
下の処理が実行される。また、前述した S107の判断が肯定される場合には、 S116 において、前記搬送波発生部 20により発生させられる搬送波の周波数設定値 fが f end であるか否かが判断される。この S116の判断が否定される場合には、 S117におい て、周波数設定値 fに Δ ίが加算された後、 S101以下の処理が再び実行される力 S 116の判断が肯定される場合には、前記方向検出部 60の動作に対応する S118に ぉ 、て、前記 I相メモリ部 38及び Ζ又は Q相メモリ部 44に記憶された受信信号強度 S が読み出され、それら受信信号強度 S が比較されることで前記無線タグ 14の方向 ϊ θ Ϊ Θ The following processing is executed. If the determination in S107 described above is affirmed, it is determined in S116 whether or not the frequency set value f of the carrier wave generated by the carrier wave generation unit 20 is f end. When the determination at S116 is negative, the force at which S101 and subsequent processes are executed again after Δ ί is added to the frequency set value f at S117. When the determination at S116 is affirmative. Then, in S118 corresponding to the operation of the direction detection unit 60, the received signal strength S stored in the I-phase memory unit 38 and the 対 応 or Q-phase memory unit 44 is read out, and the received signal strength S is obtained. By comparing, the direction of the wireless tag 14 ϊ θ Ϊ Θ
が検出された後、本ルーチンが終了させられる。 Is detected, the routine is terminated.
[0107] このように、本実施例によれば、前記無線タグ 14への無線信号を送信するため及 び/又はその無線タグ 14力もの無線信号を受信するための、それぞれ複数のアン テナ素子 26により構成される複数組のアレイアンテナ 16と、それら複数組のアレイァ ンテナ 16それぞれによる送信及び Ζ又は受信の結果、受信される受信信号を比較 することで前記無線タグ 14の方向を検出する方向検出部 60 (S109、 S110、 Si l l 、 S112、 S114、 S118)とを、備えたものであることから、前記受信信号を比較してマ ルチパスの影響が少ないアレイアンテナ 16による受信結果を用いることで、前記無 線タグ 14の方向を好適に検出することができる。すなわち、マルチパスの影響を軽減 して好適な方向検出を実現する方向検出装置を提供することができる。 Thus, according to the present embodiment, a plurality of antenna elements each for transmitting a radio signal to the radio tag 14 and / or for receiving a radio signal of the power of the radio tag 14 are used. Direction in which the direction of the wireless tag 14 is detected by comparing the received signals received as a result of transmission, reception, or reception by the plurality of array antennas 16 each including the plurality of array antennas 16 configured by 26. Since the detection unit 60 (S109, S110, Sill, S112, S114, S118) is provided, the reception result of the array antenna 16 that has less influence of multipath is used by comparing the reception signals. Thus, the direction of the wireless tag 14 can be suitably detected. That is, it is possible to provide a direction detection device that realizes suitable direction detection by reducing the influence of multipath.
[0108] また、前記複数^ &のアレイアンテナ 16それぞれの送信指向性及び Z又は受信指 向性を制御する指向性制御部 54 (S102及び S106)を備え、前記方向検出部 60は 、その指向性制御部 54により前記複数組のアレイアンテナ 16それぞれの送信指向 性及び Z又は受信指向性を制御し、各送信指向性及び Z又は受信指向性に対応し
て受信される受信信号を比較することで前記無線タグ 14の方向を検出するものであ るため、前記複数組のアレイアンテナ 16それぞれにおける各送信指向性及び Z又 は受信指向性に対応して受信される受信信号を比較してマルチパスの影響が少な いアレイアンテナ 16による受信結果を用いることで、前記無線タグ 14の方向を好適 に検出することができる。 [0108] Further, it includes a directivity control unit 54 (S102 and S106) for controlling the transmission directivity and Z or reception directivity of each of the multiple & array antennas 16, and the direction detection unit 60 includes the directivity control unit 54. The control unit 54 controls the transmission directivity and Z or reception directivity of each of the plurality of sets of array antennas 16 and corresponds to each transmission directivity and Z or reception directivity. The direction of the wireless tag 14 is detected by comparing the received signals received in response to each of the transmission directivities and Z or reception directivities in each of the plurality of sets of array antennas 16. By comparing the received signals received and using the reception result by the array antenna 16 that is less affected by multipath, the direction of the wireless tag 14 can be suitably detected.
[0109] また、前記アレイアンテナ 16により受信される受信信号の信号強度を検出する信号 強度検出部 56 (S104)を備え、前記方向検出部 60は、その信号強度検出部 56によ り検出される信号強度に応じて前記無線タグ 14の方向を検出するものであるため、 実用的な態様で前記無線タグ 14の方向を検出することができる。 [0109] Further, a signal strength detection unit 56 (S104) for detecting the signal strength of the received signal received by the array antenna 16 is provided, and the direction detection unit 60 is detected by the signal strength detection unit 56. Therefore, the direction of the wireless tag 14 can be detected in a practical manner.
[0110] また、前記複数組のアレイアンテナ 16を構成するアンテナ素子 26のうち、少なくと も 1つのアンテナ素子 26はそれら複数組のアレイアンテナ 16に共用されるものである ため、前記複数^ 1_のアレイアンテナ 16が占める空間を可及的に小さくすることができ 、延いては装置を小型化できる。 [0110] Further, among the antenna elements 26 constituting the plural sets of array antennas 16, at least one antenna element 26 is shared by the plural sets of array antennas 16, so The space occupied by the _ array antenna 16 can be made as small as possible, and the apparatus can be downsized.
[0111] また、前記複数組のアレイアンテナ 16のうち何れ力 1組のアレイアンテナ 16により 選択的に前記無線タグ 14に対する無線信号が送信及び Z又は受信されるように回 路を切り替えるアンテナ選択制御部 52 (S101及び S108)を有するものであるため、 そのアンテナ選択制御部 52により前記無線タグ 14に対する無線信号を送信及び Z 又は受信するアレイアンテナ 16を順次切り替えてゆくことで、各アレイアンテナ 16に 対応して受信信号処理回路を設ける必要がなぐ装置の構成を簡単なものとすること ができる。 [0111] Further, the antenna selection control for switching the circuit so that the radio signal to the radio tag 14 is selectively transmitted and Z or received by any one of the array antennas 16 of the plurality of array antennas 16 Since each of the array antennas 16 (S101 and S108) is sequentially switched by the antenna selection control unit 52 to transmit and Z or receive the radio signal for the radio tag 14, the array antenna 16 Therefore, it is possible to simplify the configuration of the device that does not require the reception signal processing circuit to be provided.
[0112] また、前記方向検出部 60 (S 109)は、前記指向性制御部 54により前記複数組のァ レイアンテナ 16それぞれの送信指向性及び Z又は受信指向性を制御し、各送信指 向性及び Z又は受信指向性に対応して受信される受信信号について前記信号強度 検出部 56により検出される検出結果を一通り比較し、その検出結果が最大値をとる 送信指向性及び Z又は受信指向性に対応する方向を前記無線タグ 14の方向として 検出するものであるため、実用的な態様で前記無線タグ 14の方向を検出することが できる。 [0112] Further, the direction detection unit 60 (S109) controls the transmission directivity and Z or reception directivity of each of the plurality of sets of array antennas 16 by the directivity control unit 54, and transmits each transmission direction. The received signal received corresponding to the transmission characteristics and Z or reception directivity is compared with the detection results detected by the signal intensity detection unit 56, and the detection result takes the maximum value. Since the direction corresponding to the directivity is detected as the direction of the wireless tag 14, the direction of the wireless tag 14 can be detected in a practical manner.
[0113] また、前記方向検出部 60 (S 110)は、前記指向性制御部 54により前記複数組のァ
レイアンテナ 16それぞれの送信指向性及び Z又は受信指向性を制御し、各送信指 向性及び Z又は受信指向性に対応して受信される受信信号について前記信号強度 検出部 56により検出される検出結果を比較し、その検出結果が前記複数組のアレイ アンテナ 16何れにおいても所定の閾値以上となる送信指向性及び Z又は受信指向 性に対応する方向を前記無線タグ 14の方向として検出するものであるため、実用的 な態様で前記無線タグ 14の方向を検出することができる。 [0113] Further, the direction detection unit 60 (S110) is configured to transmit the plurality of sets of keys by the directivity control unit 54. The detection of the received signal received corresponding to each transmission directivity and Z or reception directivity is detected by the signal intensity detector 56 by controlling the transmission directivity and Z or reception directivity of each of the ray antennas 16. Compare the results, and detect the direction corresponding to the transmission directivity and Z or reception directivity that the detection result is equal to or greater than a predetermined threshold in any of the plurality of sets of array antennas 16 as the direction of the wireless tag 14. Therefore, the direction of the wireless tag 14 can be detected in a practical manner.
[0114] また、前記方向検出部 60 (S111)は、前記指向性制御部 54により前記複数組のァ レイアンテナ 16それぞれの送信指向性及び Z又は受信指向性を制御し、各送信指 向性及び Z又は受信指向性に対応して受信される受信信号について前記信号強度 検出部 56により検出される検出結果を比較し、前記複数組のアレイアンテナ 16のう ちその検出結果の変動が最も少ないアレイアンテナ 16においてその検出結果が最 大値をとる送信指向性及び Z又は受信指向性に対応する方向を前記無線タグ 14の 方向として検出するものであるため、実用的な態様で前記無線タグ 14の方向を検出 することができる。 [0114] Further, the direction detection unit 60 (S111) controls the transmission directivity and Z or reception directivity of each of the plurality of sets of array antennas 16 by the directivity control unit 54, and transmits each transmission directivity. And the detection results detected by the signal intensity detection unit 56 for received signals received corresponding to Z or reception directivity, and the variation in the detection results of the plurality of sets of array antennas 16 is the least. The direction corresponding to the transmission directivity and Z or reception directivity at which the detection result of the array antenna 16 takes the maximum value is detected as the direction of the wireless tag 14, so that the wireless tag 14 is used in a practical manner. The direction of can be detected.
[0115] また、前記方向検出部 60 (S112)は、前記指向性制御部 54により前記複数組のァ レイアンテナ 16それぞれの送信指向性及び Z又は受信指向性を制御し、各受信指 向性に対応して受信される受信信号について前記信号強度検出部 56により検出さ れる検出結果を平均し、その平均の最も大きなアレイアンテナ 16にお 、て前記検出 結果が最大値をとる送信指向性及び Z又は受信指向性に対応する方向を前記無線 タグ 14の方向として検出するものであるため、実用的な態様で前記無線タグ 14の方 向を検出することができる。 [0115] Further, the direction detection unit 60 (S112) controls the transmission directivity and Z or the reception directivity of each of the plurality of sets of array antennas 16 by the directivity control unit 54, and each reception directivity. The detection results detected by the signal intensity detection unit 56 are averaged with respect to the received signals received corresponding to the transmission antennas, and the transmission directivity and the maximum detection value of the array antenna 16 having the largest average are obtained. Since the direction corresponding to Z or the reception directivity is detected as the direction of the wireless tag 14, the direction of the wireless tag 14 can be detected in a practical manner.
[0116] また、前記アレイアンテナ 16は、互いに平行を成すように配設された複数本の直線 状アンテナ素子 26から構成されるものであるため、複数本の直線状アンテナ素子 26 力も成る実用的なアレイアンテナ 16を有する方向検出装置においてマルチパスの影 響を軽減して好適な方向検出を実現することができる。 [0116] Since the array antenna 16 is composed of a plurality of linear antenna elements 26 arranged so as to be parallel to each other, the array antenna 16 is practically composed of a plurality of linear antenna elements 26. In a direction detection apparatus having a flexible array antenna 16, it is possible to reduce the influence of multipath and realize suitable direction detection.
[0117] また、前記アレイアンテナ 16を構成する複数本の直線状アンテナ素子 26のうち、 相互に最も離れて配設された直線状アンテナ素子 26相互間の距離は、前記無線信 号の搬送波の波長以下であるため、前記複数組のアレイアンテナ 16が占める空間を
可及的に小さくすることができ、延いては装置を小型化できる。 [0117] Of the plurality of linear antenna elements 26 constituting the array antenna 16, the distance between the linear antenna elements 26 arranged farthest from each other is determined by the carrier of the radio signal. The space occupied by the multiple sets of array antennas 16 is less than the wavelength. It can be made as small as possible, and thus the apparatus can be miniaturized.
[0118] また、前記複数組のアレイアンテナ 16は、互いに平行を成すように配設された 3本 の直線状アンテナ素子 26のうち相互に隣接する 2本ずつの直線状アンテナ素子 26 からそれぞれ構成される 2糸且のアレイアンテナ 16であるため、互 ヽに平行を成すよう に配設された 3本の直線状アンテナ素子 26から選択的に構成される 2組のアレイァ ンテナ 16それぞれに対応する受信信号を比較することで、前記無線タグ 14の方向 を好適に検出することができる。 [0118] Further, the plurality of sets of array antennas 16 are respectively composed of two linear antenna elements 26 adjacent to each other among the three linear antenna elements 26 arranged so as to be parallel to each other. 2 array antennas 16 that correspond to two sets of array antennas 16 that are selectively composed of three linear antenna elements 26 arranged so as to be parallel to each other. By comparing the received signals, the direction of the wireless tag 14 can be suitably detected.
[0119] また、前記複数組のアレイアンテナ 16は、互いに平行を成すように配設された 3本 の直線状アンテナ素子 26のうち相互に隣接する 2本ずつの直線状アンテナ素子 26 力もそれぞれ構成される 2組のアレイアンテナ 16、及び相互に最も離れて配設された 2本の直線状アンテナ素子 26から構成される 1組のアレイアンテナ 16であるため、互 いに平行を成すように配設された 3本の直線状アンテナ素子 26から選択的に構成さ れる 3組のアレイアンテナ 16それぞれに対応する受信信号を比較することで、前記 無線タグ 14の方向を好適に検出することができる。 [0119] In addition, the plurality of sets of array antennas 16 also includes two linear antenna elements 26 adjacent to each other among the three linear antenna elements 26 arranged so as to be parallel to each other. The two array antennas 16 and the two array antennas 16 that are arranged at the furthest distance from each other are arranged in parallel with each other. By comparing the received signals corresponding to each of the three sets of array antennas 16 that are selectively configured from the three linear antenna elements 26 provided, the direction of the wireless tag 14 can be suitably detected. .
[0120] また、前記方向検出部 60は、予め定められた所定の相対角度範囲に対応して前 記指向性制御部 54により前記複数組のアレイアンテナ 16それぞれの送信指向性及 び Z又は受信指向性を制御し、各送信指向性及び Z又は受信指向性に対応して受 信される受信信号を比較することで前記無線タグ 14の方向を検出するものであるた め、予め方向検出の対象となる範囲を限定しておくことで、前記無線タグ 14の検出 に要する時間を短縮することができる。 [0120] Further, the direction detection unit 60 corresponds to a predetermined relative angle range determined in advance, and the directivity control unit 54 performs transmission directivity and Z or reception of each of the plurality of sets of array antennas 16. The direction of the wireless tag 14 is detected by controlling the directivity and comparing the received signals received corresponding to each transmission directivity and Z or reception directivity. By limiting the target range, the time required to detect the wireless tag 14 can be shortened.
[0121] また、前記複数^ &のアレイアンテナ 16それぞれにより送信及び Z又は受信を行つ た結果、受信される受信信号を比較することで障害物の存在する方向を検出する障 害物方向検出部 58 (S113)を備え、前記方向検出部 60 (S114)は、その障害物方 向検出部 58により障害物が検出された方向、又は障害物方向設定部 59に設定され た方向を除外して前記無線タグ 14の方向を検出するものであるため、マルチパス発 生の原因となる障害物が存在する方向を避けることで、前記無線タグ 14の方向を好 適に検出することができる。 [0121] In addition, obstacle direction detection that detects the direction in which an obstacle exists by comparing the received signals as a result of transmission and Z or reception by each of the array antennas 16 of multiple & 58 (S113), the direction detection unit 60 (S114) excludes the direction in which the obstacle is detected by the obstacle direction detection unit 58 or the direction set in the obstacle direction setting unit 59. Since the direction of the wireless tag 14 is detected, the direction of the wireless tag 14 can be suitably detected by avoiding the direction in which an obstacle causing multipath occurs.
[0122] また、本実施例の方向検出装置は、検出対象である無線タグ 14に向けて所定の送
信信号を送信すると共に、その送信信号に応答して前記無線タグ 14から返信される 返信信号を受信することで前記無線タグ 14の方向を検出する無線タグ方向検出装 置 12であるため、マルチパスの影響を軽減して好適な無線タグ方向の検出を実現す る無線タグ方向検出装置を提供することができる。 [0122] In addition, the direction detection device according to the present embodiment transmits a predetermined transmission toward the wireless tag 14 to be detected. Since the wireless tag direction detection device 12 detects the direction of the wireless tag 14 by receiving a reply signal transmitted from the wireless tag 14 in response to the transmission signal, It is possible to provide a wireless tag direction detection device that realizes detection of a preferable wireless tag direction by reducing the influence of a path.
[0123] また、前記方向検出部 60 (S 108)は、前記送信信号の搬送波の周波数を変化さ せ、各周波数に対応して受信される受信信号を比較することで前記無線タグ 14の方 向を検出するものであるため、複数の搬送波周波数それぞれにおける各受信指向性 に対応して受信される受信信号を比較してマルチパスの影響が少ない搬送波周波 数による受信結果を用いることで、前記無線タグ 14の方向を好適に検出することが できる。 [0123] Further, the direction detection unit 60 (S108) changes the frequency of the carrier wave of the transmission signal, and compares the reception signal received corresponding to each frequency, thereby comparing the direction of the wireless tag 14 Therefore, by comparing the received signals received corresponding to each reception directivity at each of a plurality of carrier frequencies, and using the reception result with the carrier frequency with less multipath influence, The direction of the wireless tag 14 can be detected suitably.
[0124] 続いて、本第 2発明の方向検出装置の他の好適な実施例を図面に基づいて詳細 に説明する。図 25は、本第 2発明の方向検出装置の他の好適な実施例である無線 タグ通信装置 94の構成を説明する図である。この図 25に示すように、本実施例の無 線タグ通信装置 94は、前記送受信モジュール 24a及び 24bから供給される受信信 号を合成 (加算)する合波部である受信信号合成部 28aと、その受信信号合成部 28 aから供給される合成信号を増幅する可変増幅部 30aと、その可変増幅部 30aから供 給される合成信号をホモダイン検波するホモダイン検波回路 32aと、そのホモダイン 検波回路 32aから出力される I相信号のうち所定の周波数帯域の信号のみ通過させ る I相 LPF34aと、その I相 LPF34aを通過した I相信号をディジタル変換する I相 AZ D変換部 36aと、その I相 AZD変換部 36aによりディジタル変換された信号を記憶す る I相メモリ部 38aと、上記ホモダイン検波回路 32aから出力される Q相信号のうち所 定の周波数帯域の信号のみ通過させる Q相 LPF40aと、その Q相 LPF40aを通過し た Q相信号をディジタル変換する Q相 AZD変換部 42aと、その Q相 AZD変換部 42 aによりディジタル変換された信号を記憶する Q相メモリ部 44aと、前記送受信モジュ ール 24b及び 24cから供給される受信信号を合成 (加算)する合波部である受信信 号合成部 28bと、その受信信号合成部 28bから供給される合成信号を増幅する可変 増幅部 30bと、その可変増幅部 30bから供給される合成信号をホモダイン検波する ホモダイン検波回路 32bと、そのホモダイン検波回路 32bから出力される I相信号のう
ち所定の周波数帯域の信号のみ通過させる I相 LPF34bと、その I相 LPF34bを通過 した I相信号をディジタル変換する I相 AZD変換部 36bと、その I相 AZD変換部 36b によりディジタル変換された信号を記憶する I相メモリ部 38bと、上記ホモダイン検波 回路 32bから出力される Q相信号のうち所定の周波数帯域の信号のみ通過させる Q 相 LPF40bと、その Q相 LPF40bを通過した Q相信号をディジタル変換する Q相 AZ D変換部 42bと、その Q相 AZD変換部 42bによりディジタル変換された信号を記憶 する Q相メモリ部 44bとを、備えて構成されている。 [0124] Next, another preferred embodiment of the direction detection device of the second invention will be described in detail with reference to the drawings. FIG. 25 is a view for explaining the configuration of an RFID tag communication apparatus 94 which is another preferred embodiment of the direction detection apparatus of the second invention. As shown in FIG. 25, the wireless tag communication device 94 of this embodiment includes a received signal combining unit 28a that is a combining unit that combines (adds) the received signals supplied from the transmission / reception modules 24a and 24b. A variable amplification unit 30a that amplifies the combined signal supplied from the received signal combining unit 28a, a homodyne detection circuit 32a that detects the combined signal supplied from the variable amplification unit 30a, and a homodyne detection circuit 32a I-phase LPF34a that passes only signals in the specified frequency band from the I-phase signal output from the I-phase AZ D converter 36a that digitally converts the I-phase signal that has passed through the I-phase LPF 34a, and its I-phase An I-phase memory unit 38a for storing the signal digitally converted by the AZD conversion unit 36a, a Q-phase LPF 40a for passing only a signal in a predetermined frequency band among the Q-phase signals output from the homodyne detection circuit 32a, Q phase LP Q-phase AZD converter 42a that digitally converts the Q-phase signal that has passed through F40a, Q-phase memory 44a that stores the signal digitally converted by the Q-phase AZD converter 42a, and the transmission / reception module 24b Receiving signal synthesizer 28b that combines (adds) received signals supplied from 24c, variable amplifying unit 30b that amplifies the combined signal supplied from the received signal combining unit 28b, and its variable A homodyne detection circuit 32b that detects the combined signal supplied from the amplification unit 30b and the I-phase signal output from the homodyne detection circuit 32b. The I-phase LPF34b that passes only signals in the specified frequency band, the I-phase AZD converter 36b that digitally converts the I-phase signal that has passed through the I-phase LPF34b, and the signal digitally converted by the I-phase AZD converter 36b I-phase memory 38b, Q-phase LPF40b that passes only signals in the specified frequency band among the Q-phase signals output from the homodyne detection circuit 32b, and Q-phase signals that have passed through the Q-phase LPF40b are digital A Q-phase AZ D conversion unit 42b for conversion and a Q-phase memory unit 44b for storing signals digitally converted by the Q-phase AZD conversion unit 42b are provided.
[0125] このように、本実施例の無線タグ通信装置 94は、前記アレイアンテナ 16aに対応し て受信信号合成部 28a、可変増幅部 30a、及びホモダイン検波回路 32a等の受信信 号処理回路を、前記アレイアンテナ 16bに対応して受信信号合成部 28b、可変増幅 部 30b、及びホモダイン検波回路 32b等の受信信号処理回路を、それぞれ独立に有 しており、前記アレイアンテナ 16a、 16bは、前記無線タグ 14力もの無線信号を同時 に受信するように構成されているため、前記無線信号の処理時間を可及的に短縮す ることができ、延いては前記無線タグ 14の検出に要する時間を短縮することができる As described above, the RFID tag communication apparatus 94 according to the present embodiment includes reception signal processing circuits such as the reception signal synthesis unit 28a, the variable amplification unit 30a, and the homodyne detection circuit 32a corresponding to the array antenna 16a. Corresponding to the array antenna 16b, reception signal processing circuits such as a reception signal synthesis unit 28b, a variable amplification unit 30b, and a homodyne detection circuit 32b are provided independently, and the array antennas 16a and 16b The wireless tag is configured to receive as many as 14 wireless signals at the same time, so the processing time of the wireless signal can be shortened as much as possible, and thus the time required for detection of the wireless tag 14 Can be shortened
[0126] 図 26は、本第 2発明の方向検出装置の更に別の好適な実施例である無線タグ通 信装置 96の構成を説明する図である。この図 26に示すように、本実施例の無線タグ 通信装置 96は、前記アンテナ素子 26a、 26b、 26cに加えてアンテナ素子 26dを有 しており、そのアンテナ素子 26dに対応して送受信モジュール 24dを備えている。こ の送受信モジュール 24dは、図 3を用いて前述した送受信モジュール 24a、 24b、 24 c等と同様の構成とされたものであり、前記搬送波増幅部 22から供給される搬送波に 基づく送信信号を処理してアンテナ素子 26dから送信すると共にそのアンテナ素子 2 6dにより受信される受信信号を処理して前記受信信号合成部 28へ供給する。また、 前記搬送波増幅部 22と送受信モジュール 24bとの間の信号伝達回路を開閉する送 信回路切替部 46bと、上記搬送波増幅部 22と送受信モジュール 24dとの間の信号 伝達回路を開閉する送信回路切替部 46dと、上記送受信モジュール 24bと受信信 号合成部 28との間の信号伝達回路を開閉する受信回路切替部 48bと、上記送受信 モジュール 24dと受信信号合成部 28との間の信号伝達回路を開閉する受信回路切
替部 48dとを、備えており、前記受信信号合成部 28は、前記受信回路切替部 48a、 48b、 48c、 48dの開閉に応じて前記送受信モジユーノレ 24a、 24b、 24c、 24d力ら選 択的に供給される受信信号を合成する。 FIG. 26 is a diagram for explaining the configuration of a wireless tag communication device 96 that is still another preferred embodiment of the direction detection device according to the second aspect of the present invention. As shown in FIG. 26, the RFID tag communication apparatus 96 of the present embodiment has an antenna element 26d in addition to the antenna elements 26a, 26b, and 26c, and a transmission / reception module 24d corresponding to the antenna element 26d. It has. This transmission / reception module 24d has the same configuration as the transmission / reception modules 24a, 24b, 24c, etc. described above with reference to FIG. 3, and processes transmission signals based on the carrier wave supplied from the carrier wave amplification unit 22. The received signal transmitted from the antenna element 26d and received by the antenna element 26d is processed and supplied to the received signal combining unit 28. Also, a transmission circuit switching unit 46b that opens and closes a signal transmission circuit between the carrier wave amplification unit 22 and the transmission / reception module 24b, and a transmission circuit that opens and closes a signal transmission circuit between the carrier wave amplification unit 22 and the transmission / reception module 24d. A switching unit 46d, a reception circuit switching unit 48b for opening and closing a signal transmission circuit between the transmission / reception module 24b and the reception signal synthesis unit 28, and a signal transmission circuit between the transmission / reception module 24d and the reception signal synthesis unit 28. Open / close receiving circuit The reception signal synthesizer 28 is selectively selected from the transmission / reception modules 24a, 24b, 24c, 24d according to the opening / closing of the reception circuit switching units 48a, 48b, 48c, 48d. Is combined with the received signal.
[0127] 本実施例の無線タグ通信装置 96に備えられた 4つのアンテナ素子 26は、何れもダ イポールアンテナ等の直線状アンテナ素子であり、それら複数の直線状アンテナ素 子 26が同一平面内に互いに平行を成すように且つ等間隔で配設されたものである。 そして、それら 4本の直線状アンテナ素子 26のうち少なくとも 2本のアンテナ素子 26 力も送信及び Z又は受信におけるアレイアンテナ 16が構成される。例えば、上記 4 本の直線状アンテナ素子 26のうち相互に隣接する 2本の直線状アンテナ素子 26か ら 3組のアレイアンテナ 16が構成される。すなわち、上記アンテナ素子 26a及び 26b からアレイアンテナ 16aが、アンテナ素子 26b及び 26cからアレイアンテナ 16bが、ァ ンテナ素子 26c及び 26dからアレイアンテナ 16cがそれぞれ構成される。また、上記 4 本の直線状アンテナ素子 26のうち選択される何れ力 3本の直線状アンテナ素子 26 力も 2組のアレイアンテナ 16が構成される。すなわち、上記アンテナ素子 26a、 26b、 26cからアレイアンテナ 16d力 アンテナ素子 26b、 26c、 26dからアレイアンテナ 16 eがそれぞれ構成される。前記無線タグ通信装置 96では、前記アンテナ選択制御部 52により前記送信回路切替部 46及び Z又は受信回路切替部 48を介して上述のよう な複数組のアレイアンテナ 16が選択的に成立させられ、そのアレイアンテナ 16により 前記無線タグ 14に対する無線信号の送信及び Z又は受信が行われる。 [0127] The four antenna elements 26 provided in the RFID tag communication apparatus 96 of the present embodiment are all linear antenna elements such as dipole antennas, and the plurality of linear antenna elements 26 are in the same plane. Are arranged at equal intervals so as to be parallel to each other. Of these four linear antenna elements 26, at least two antenna element 26 forces constitute the array antenna 16 for transmission and Z or reception. For example, three sets of array antennas 16 are constituted by two linear antenna elements 26 adjacent to each other among the four linear antenna elements 26. That is, the antenna elements 26a and 26b constitute an array antenna 16a, the antenna elements 26b and 26c constitute an array antenna 16b, and the antenna elements 26c and 26d constitute an array antenna 16c. Further, any of the three linear antenna elements 26 selected from the four linear antenna elements 26 constitutes two sets of array antennas 16. That is, the antenna elements 26a, 26b, and 26c constitute the array antenna 16d, and the antenna elements 26b, 26c, and 26d constitute the array antenna 16e. In the RFID tag communication device 96, a plurality of sets of array antennas 16 as described above are selectively established by the antenna selection control unit 52 via the transmission circuit switching unit 46 and Z or the reception circuit switching unit 48. The array antenna 16 transmits and Z or receives a wireless signal to the wireless tag 14.
[0128] このように、本実施例によれば、前記複数組のアレイアンテナ 16は、互いに平行を 成すように配設された 4本の直線状アンテナ素子 26のうち相互に隣接する 2本の直 線状アンテナ素子 26から構成される 3組のアレイアンテナ 16a、 16b、 16cであるた め、互いに平行を成すように配設された 4本の直線状アンテナ素子 26から選択的に 構成される 3組のアレイアンテナ 16a、 16b、 16cそれぞれに対応する受信信号を比 較することで、前記無線タグ 14の方向を好適に検出することができる。 [0128] Thus, according to the present embodiment, the plurality of sets of array antennas 16 includes two linear antenna elements 26 arranged so as to be parallel to each other and two adjacent to each other. Since there are three sets of array antennas 16a, 16b, 16c composed of linear antenna elements 26, they are selectively composed of four linear antenna elements 26 arranged in parallel to each other. By comparing the received signals corresponding to the three sets of array antennas 16a, 16b, and 16c, the direction of the wireless tag 14 can be suitably detected.
[0129] また、前記複数組のアレイアンテナ 16は、互いに平行を成すように配設された 4本 の直線状アンテナ素子 26のうち選択される何れ力 3本の直線状アンテナ素子 26から 構成される 2組のアレイアンテナ 16d、 16eであるため、互いに平行を成すように配設
された 4本の直線状アンテナ素子 26から選択的に構成される 2組のアレイアンテナ 1 6それぞれに対応する受信信号を比較することで、前記無線タグ 14の方向を好適に 検出することができる。 [0129] Further, the plurality of sets of array antennas 16 are composed of any three linear antenna elements 26 selected from four linear antenna elements 26 arranged so as to be parallel to each other. 2 sets of array antennas 16d and 16e, so they are arranged parallel to each other The direction of the wireless tag 14 can be suitably detected by comparing the received signals corresponding to each of the two sets of array antennas 16 that are selectively composed of the four linear antenna elements 26 .
[0130] 以上、本第 2発明の好適な実施例を図面に基づいて詳細に説明したが、本第 2発 明はこれに限定されるものではなぐ更に別の態様においても実施される。 [0130] The preferred embodiment of the second invention has been described in detail with reference to the drawings. However, the second invention is not limited to this embodiment, and may be implemented in another mode.
[0131] 例えば、前述の実施例において、前記アンテナ選択制御部 52、指向性制御部 54 、信号強度検出部 56、障害物方向検出部 58、障害物方向設定部 59、及び方向検 出部 60等は、何れも個別に設けられたものであつたが、本第 2発明はこれに限定さ れるものではなぐそれらと同等の制御機能が CPU、 ROM, RAM等を含んでデイジ タル信号処理を実行する DSP (Digital Signal Processor)等に機能的に備えられたも のであっても構わない。また、それら制御装置による制御は、ディジタル信号処理で あるとアナログ信号処理であるとを問わな 、。 [0131] For example, in the above-described embodiment, the antenna selection control unit 52, the directivity control unit 54, the signal strength detection unit 56, the obstacle direction detection unit 58, the obstacle direction setting unit 59, and the direction detection unit 60 However, the second invention is not limited to this, and the same control functions as those include CPU, ROM, RAM, etc. for digital signal processing. A DSP (Digital Signal Processor) to be executed or the like may be functionally provided. Regardless of whether the control by these control devices is digital signal processing or analog signal processing.
[0132] また、前述の実施例において、前記無線タグ通信装置 93に備えられたアンテナ素 子 26は、何れもダイポールアンテナ等の直線状アンテナ素子であり、それら複数本 の直線状アンテナ素子 26から複数組のアレイアンテナ 16が構成されるものであった 力 例えばパッチアンテナ等の平板状 (平面)アンテナ素子力もアレイアンテナが構 成されるものであってもよぐ斯カるアンテナを備えた通信装置にも本第 2発明は好 適に適用され得る。 In the above-described embodiment, each of the antenna elements 26 provided in the RFID tag communication device 93 is a linear antenna element such as a dipole antenna, and the plurality of linear antenna elements 26 are used. Forces that consist of multiple sets of array antennas 16 For example, a flat (planar) antenna element force such as a patch antenna may be used to configure an array antenna. The second invention can be suitably applied to an apparatus.
[0133] また、前述の実施例では、通信対象である無線タグ 14に向けて所定の送信信号を 送信すると共に、その送信信号に応答して前記無線タグ 14から返信される返信信号 を受信することで前記無線タグ 14との間で情報の通信を行う無線タグ通信装置 93に 本第 2発明が適用された例について説明したが、例えば携帯電話機や移動体通信 装置をはじめとする他の無線通信装置における通信端末の方向検出にも本第 2発明 は好適に適用され得る。 [0133] In the above-described embodiment, a predetermined transmission signal is transmitted to the wireless tag 14 that is a communication target, and a reply signal returned from the wireless tag 14 in response to the transmission signal is received. Thus, the example in which the second invention is applied to the wireless tag communication device 93 that performs information communication with the wireless tag 14 has been described. However, other wireless devices such as a mobile phone and a mobile communication device have been described. The second aspect of the present invention can also be suitably applied to direction detection of a communication terminal in a communication device.
[0134] その他、一々例示はしないが、本第 2発明はその趣旨を逸脱しない範囲内におい て種々の変更が加えられて実施されるものである。
[0134] Although not illustrated one by one, the second invention is implemented with various modifications within the scope not departing from the gist thereof.
Claims
[1] 無線端末に対して無線信号の送信及び Z又は受信を行 ヽ、該無線信号に基づ 、 て該無線端末の方向を検出する方向検出装置であって、 [1] A direction detection device that performs transmission and Z or reception of a wireless signal to a wireless terminal, and detects the direction of the wireless terminal based on the wireless signal,
前記無線端末への無線信号を送信するため及び Z又は該無線端末力 の無線信 号を受信するための、複数のアンテナ素子により構成されるアレイアンテナと、 それら複数のアンテナ素子それぞれに対応する位相を制御することで前記アレイァ ンテナの送信指向性及び Z又は受信指向性を制御する指向性制御部と、 An array antenna composed of a plurality of antenna elements for transmitting a radio signal to the radio terminal and receiving a radio signal of Z or the radio terminal power, and a phase corresponding to each of the plurality of antenna elements A directivity control unit for controlling the transmission directivity and Z or reception directivity of the array antenna by controlling
該指向性制御部により前記アレイアンテナの送信指向性及び Z又は受信指向性を 第 1の角度に対応する指向性方向とした場合において受信される受信信号と、該第 1の角度力 所定の偏差角度ずらした第 2の角度に対応する指向性方向とした場合 において受信される受信信号とを、比較することで前記無線端末の方向を検出する 方向検出部と Received signal received when the directivity control unit sets the transmission directivity and Z or reception directivity of the array antenna to the directivity direction corresponding to the first angle, and the first angular force predetermined deviation A direction detection unit that detects the direction of the wireless terminal by comparing the received signal received in the case of the directivity direction corresponding to the second angle shifted in angle;
を、備えたものであることを特徴とする方向検出装置。 A direction detecting device characterized by comprising:
[2] 前記アレイアンテナにより受信される受信信号の信号強度を検出する信号強度検 出部を備え、前記方向検出部は、該信号強度検出部により検出される信号強度に応 じて前記無線端末の方向を検出するものである請求項 1の方向検出装置。 [2] A signal strength detection unit that detects a signal strength of a reception signal received by the array antenna is provided, and the direction detection unit is configured to correspond to the signal strength detected by the signal strength detection unit. The direction detection device according to claim 1, wherein the direction detection device detects a direction of.
[3] 前記方向検出部は、前記第 1の角度を所定角度ずつ段階的に変化させつつ該第 1の角度に対応する指向性方向とした場合において受信される受信信号又はその信 号強度と、前記第 2の角度に対応する指向性方向とした場合において受信される受 信信号又はその信号強度とを、所定の記憶装置に記憶し、該記憶装置に記憶され た受信信号又はその信号強度を比較することで前記無線端末の方向を検出するも のである請求項 2の方向検出装置。 [3] The direction detection unit receives the received signal or its signal strength when the first angle is changed stepwise by a predetermined angle and the directivity direction corresponds to the first angle. The received signal received in the direction of directivity corresponding to the second angle or the signal strength thereof is stored in a predetermined storage device, and the received signal stored in the storage device or the signal strength thereof is stored. 3. The direction detection device according to claim 2, wherein the direction of the wireless terminal is detected by comparing the two.
[4] 前記偏差角度は、前記第 1の角度の段階的な変化分である所定角度の 1Z10以 上 1Z5以下である請求項 3の方向検出装置。 4. The direction detecting device according to claim 3, wherein the deviation angle is not less than 1Z10 and not more than 1Z5 of a predetermined angle that is a stepwise change in the first angle.
[5] 前記偏差角度は、 1乃至 2° の範囲内である請求項 1から 4の何れかの方向検出装 置。 [5] The direction detection device according to any one of claims 1 to 4, wherein the deviation angle is within a range of 1 to 2 °.
[6] 前記偏差角度は、前記無線端末の方向検出における許容誤差角度以下である請 求項 1から 5の何れかの方向検出装置。
[6] The direction detection device according to any one of claims 1 to 5, wherein the deviation angle is equal to or smaller than an allowable error angle in direction detection of the wireless terminal.
[7] 前記方向検出部は、先ず、前記第 1の角度を所定角度ずつ段階的に変化させつ つ前記指向性制御部により前記アレイアンテナの送信指向性及び Z又は受信指向 性をそれぞれの第 1の角度に対応する指向性方向とした場合において受信される受 信信号又はその信号強度を前記記憶装置に記憶し、次に、前記第 1の角度を所定 角度ずつ段階的に変化させつつ前記指向性制御部により前記アレイアンテナの送 信指向性及び Z又は受信指向性をそれぞれの第 1の角度から所定の偏差角度ずら した第 2の角度に対応する指向性方向とした場合において受信される受信信号又は その信号強度を前記記憶装置に記憶し、該記憶装置に記憶された受信信号又はそ の信号強度を比較することで前記無線端末の方向を検出するものである請求項 3か ら 6の何れかの方向検出装置。 [7] The direction detection unit first changes each of the transmission directivity and Z or reception directivity of the array antenna by the directivity control unit while gradually changing the first angle by a predetermined angle. The received signal or the signal strength received in the case of the directivity direction corresponding to the angle of 1 is stored in the storage device, and then the first angle is changed step by step by a predetermined angle. Received when the directivity control unit sets the transmit directivity and Z or receive directivity of the array antenna to a directivity direction corresponding to a second angle shifted from the first angle by a predetermined deviation angle. The received signal or its signal strength is stored in the storage device, and the direction of the wireless terminal is detected by comparing the received signal stored in the storage device or its signal strength. Either Direction detection device.
[8] 前記方向検出部は、前記第 1の角度に対応する指向性方向とした場合において受 信される受信信号の信号強度が所定値以下だった場合には、該第 1の角度力 所 定の偏差角度ずらした第 2の角度に対応する指向性制御及び前記無線信号の送信 及び Z又は受信制御を行わないものである請求項 7の方向検出装置。 [8] The direction detection unit, when the signal strength of the received signal received when the directivity direction corresponds to the first angle is less than or equal to a predetermined value, 8. The direction detection device according to claim 7, wherein directivity control corresponding to a second angle shifted by a constant deviation angle and transmission and Z or reception control of the radio signal are not performed.
[9] 前記方向検出部は、前記記憶装置に記憶された各受信信号について前記信号強 度検出部により検出される検出結果を一通り比較し、該検出結果が最大値をとる送 信指向性及び Z又は受信指向性に対応する方向を前記無線端末の方向として検出 するものである請求項 2から 8の何れかの方向検出装置。 [9] The direction detection unit compares the detection results detected by the signal intensity detection unit for each received signal stored in the storage device, and the transmission directivity at which the detection result takes a maximum value. And a direction corresponding to Z or a reception directivity is detected as the direction of the wireless terminal.
[10] 前記方向検出部は、前記記憶装置に記憶された各受信信号について前記信号強 度検出部により検出される検出結果を比較し、該検出結果が前記第 1の角度に対応 する指向性方向及び第 2の角度に対応する指向性方向の何れにおいても所定の閾 値以上となる送信指向性及び Z又は受信指向性に対応する方向を前記無線端末の 方向として検出するものである請求項 2から 8の何れかの方向検出装置。 [10] The direction detection unit compares detection results detected by the signal intensity detection unit for each received signal stored in the storage device, and the detection result corresponds to the directivity corresponding to the first angle. The direction corresponding to the transmission directivity and Z or reception directivity that are equal to or greater than a predetermined threshold value in any of the direction and the directivity direction corresponding to the second angle is detected as the direction of the wireless terminal. Any direction detection device from 2 to 8.
[11] 前記方向検出部は、前記記憶装置に記憶された各受信信号について前記信号強 度検出部により検出される検出結果を比較し、前記第 1の角度に対応する指向性方 向の検出結果と第 2の角度に対応する指向性方向の検出結果との差が最も小さい 角度に対応する方向を前記無線端末の方向として検出するものである請求項 2から 8の何れかの方向検出装置。
[11] The direction detection unit compares a detection result detected by the signal intensity detection unit for each received signal stored in the storage device, and detects a directivity direction corresponding to the first angle. 9. The direction detection device according to claim 2, wherein the direction corresponding to the angle with the smallest difference between the result and the detection result of the directivity direction corresponding to the second angle is detected as the direction of the wireless terminal. .
[12] 前記方向検出部は、前記記憶装置に記憶された各受信信号について前記第 1の 角度に対応する指向性方向及び第 2の角度に対応する指向性方向それぞれに関し て前記信号強度検出部により検出される検出結果を平均し、該平均の大きな角度に 対応する指向性方向において前記検出結果が最大値をとる送信指向性及び Z又は 受信指向性に対応する方向を前記無線端末の方向として検出するものである請求 項 2から 8の何れかの方向検出装置。 [12] The direction detection unit includes the signal intensity detection unit for each of the reception signals stored in the storage device with respect to the directivity direction corresponding to the first angle and the directivity direction corresponding to the second angle. Average the detection results detected by the transmission direction, and in the directivity direction corresponding to the average large angle, the direction corresponding to the transmission directivity and Z or reception directivity where the detection result takes the maximum value is the direction of the wireless terminal. 9. The direction detection device according to claim 2, wherein the direction detection device is for detection.
[13] 前記記憶装置に記憶された各受信信号又は信号強度を比較することで障害物の 存在する方向を検出する障害物方向検出部、又は障害物の方向が既知の場合その 方向を設定する障害物方向設定部を備え、前記方向検出部は、該障害物方向検出 部により障害物が検出された方向、又は前記障害物方向設定部に設定された方向 を除外して前記無線端末の方向を検出するものである請求項 1から 12の何れかの方 向検出装置。 [13] An obstacle direction detection unit that detects a direction in which an obstacle exists by comparing each received signal or signal intensity stored in the storage device, or sets the direction of the obstacle if the direction is known An obstacle direction setting unit, wherein the direction detection unit excludes the direction in which the obstacle is detected by the obstacle direction detection unit or the direction set in the obstacle direction setting unit, and the direction of the wireless terminal The direction detecting device according to any one of claims 1 to 12, wherein the direction detecting device is a device for detecting the above.
[14] 前記方向検出装置は、検出対象である無線タグに向けて所定の送信信号を送信 すると共に、該送信信号に応答して前記無線タグから返信される返信信号を受信す ることで前記無線タグの方向を検出する無線タグ方向検出装置である請求項 1から 1 [14] The direction detection device transmits a predetermined transmission signal toward the detection target wireless tag and receives a return signal returned from the wireless tag in response to the transmission signal. The wireless tag direction detecting device for detecting a direction of the wireless tag
3の何れかの方向検出装置。 Any one of the direction detection devices of 3.
[15] 前記方向検出部は、前記送信信号の搬送波の周波数を変化させ、各周波数に対 応して受信される受信信号を比較することで前記無線タグの方向を検出するもので ある請求項 14の方向検出装置。 15. The direction detecting unit detects a direction of the wireless tag by changing a frequency of a carrier wave of the transmission signal and comparing a reception signal received corresponding to each frequency. 14 direction detection devices.
[16] 無線端末に対して無線信号の送信及び Z又は受信を行 ヽ、該無線信号に基づ 、 て該無線端末の方向を検出する方向検出装置であって、 [16] A direction detection device that performs transmission and Z or reception of a wireless signal to a wireless terminal, and detects the direction of the wireless terminal based on the wireless signal,
前記無線端末への無線信号を送信するため及び Z又は該無線端末力 の無線信 号を受信するための、それぞれ複数のアンテナ素子により構成される複数組のアレイ アンテナと、 A plurality of sets of array antennas each configured by a plurality of antenna elements for transmitting a radio signal to the radio terminal and for receiving a radio signal of Z or the radio terminal power;
それら複数組のアレイアンテナそれぞれによる送信及び Z又は受信の結果、受信 される受信信号を比較することで前記無線端末の方向を検出する方向検出部と を、備えたものであることを特徴とする方向検出装置。 A direction detection unit that detects the direction of the wireless terminal by comparing the received signals received as a result of transmission and Z or reception by each of the plurality of sets of array antennas. Direction detection device.
[17] 前記複数組のアレイアンテナそれぞれの送信指向性及び Z又は受信指向性を制
御する指向性制御部を備え、前記方向検出部は、該指向性制御部により前記複数 組のアレイアンテナそれぞれの送信指向性及び z又は受信指向性を制御し、各送 信指向性及び Z又は受信指向性に対応して受信される受信信号を比較することで 前記無線端末の方向を検出するものである請求項 16の方向検出装置。 [17] Control the transmission directivity and Z or reception directivity of each of the plurality of array antennas. A directivity control unit that controls the transmission directivity and z or reception directivity of each of the plurality of sets of array antennas by the directivity control unit, and each transmission directivity and Z or 17. The direction detection device according to claim 16, wherein the direction of the wireless terminal is detected by comparing reception signals received corresponding to reception directivities.
[18] 前記アレイアンテナにより受信される受信信号の信号強度を検出する信号強度検 出部を備え、前記方向検出部は、該信号強度検出部により検出される信号強度に応 じて前記無線端末の方向を検出するものである請求項 16又は 17の方向検出装置。 [18] A signal strength detection unit that detects a signal strength of a reception signal received by the array antenna is provided, and the direction detection unit is configured to correspond to the signal strength detected by the signal strength detection unit. 18. The direction detection device according to claim 16 or 17, wherein the direction detection device detects the direction of the direction.
[19] 前記複数組のアレイアンテナを構成するアンテナ素子のうち、少なくとも 1つのアン テナ素子はそれら複数組のアレイアンテナに共用されるものである請求項 16から 18 の何れかの方向検出装置。 19. The direction detecting device according to claim 16, wherein at least one antenna element among the antenna elements constituting the plurality of sets of array antennas is shared by the plurality of sets of array antennas.
[20] 前記複数組のアレイアンテナのうち何れか 1組のアレイアンテナにより選択的に前 記無線端末に対する無線信号が送信及び Z又は受信されるように回路を切り替える アンテナ選択制御部を有するものである請求項 16から 19の何れかの方向検出装置 [20] An antenna selection control unit that switches a circuit so that a radio signal for the wireless terminal is selectively transmitted and Z or received by any one of the plurality of array antennas. The direction detection device according to any one of claims 16 to 19
[21] 前記複数組のアレイアンテナそれぞれに対応して受信信号処理回路を有するもの であり、それら複数組のアレイアンテナは、前記無線端末からの無線信号を同時に 受信するものである請求項 16から 19の何れかの方向検出装置。 21. A reception signal processing circuit corresponding to each of the plurality of sets of array antennas, wherein the plurality of sets of array antennas simultaneously receive a radio signal from the radio terminal. Any one of 19 direction detection apparatuses.
[22] 前記方向検出部は、前記指向性制御部により前記複数組のアレイアンテナそれぞ れの送信指向性及び Z又は受信指向性を制御し、各送信指向性及び Z又は受信 指向性に対応して受信される受信信号について前記信号強度検出部により検出さ れる検出結果を一通り比較し、該検出結果が最大値をとる送信指向性及び Z又は 受信指向性に対応する方向を前記無線端末の方向として検出するものである請求 項 18から 21の何れかの方向検出装置。 [22] The direction detection unit controls the transmission directivity and Z or reception directivity of each of the plurality of sets of array antennas by the directivity control unit, and supports each transmission directivity and Z or reception directivity. The reception result received by the signal strength detection unit is compared with the detection results detected by the signal intensity detector, and the direction corresponding to the transmission directivity and the Z or reception directivity at which the detection result takes the maximum value is determined. The direction detection device according to any one of claims 18 to 21, wherein the direction detection device detects the direction as a direction.
[23] 前記方向検出部は、前記指向性制御部により前記複数組のアレイアンテナそれぞ れの送信指向性及び Z又は受信指向性を制御し、各送信指向性及び Z又は受信 指向性に対応して受信される受信信号について前記信号強度検出部により検出さ れる検出結果を比較し、該検出結果が前記複数組のアレイアンテナ何れにお!、ても 所定の閾値以上となる送信指向性及び Z又は受信指向性に対応する方向を前記無
線端末の方向として検出するものである請求項 18から 21の何れかの方向検出装置 [23] The direction detection unit controls the transmission directivity and Z or reception directivity of each of the plurality of sets of array antennas by the directivity control unit, and corresponds to each transmission directivity and Z or reception directivity. Then, the detection results detected by the signal intensity detection unit are compared for the received signal received, and the detection result is determined by any of the plurality of array antennas! However, the direction corresponding to the transmission directivity and Z or reception directivity that are equal to or greater than a predetermined threshold is not The direction detection device according to any one of claims 18 to 21, wherein the direction detection device detects the direction of the line terminal.
[24] 前記方向検出部は、前記指向性制御部により前記複数組のアレイアンテナそれぞ れの送信指向性及び Z又は受信指向性を制御し、各送信指向性及び Z又は受信 指向性に対応して受信される受信信号について前記信号強度検出部により検出さ れる検出結果を比較し、前記複数組のアレイアンテナのうち該検出結果の変動が最 も少な 、アレイアンテナにお 、て該検出結果が最大値をとる送信指向性及び Z又は 受信指向性に対応する方向を前記無線端末の方向として検出するものである請求 項 18から 21の何れかの方向検出装置。 [24] The direction detection unit controls the transmission directivity and Z or reception directivity of each of the plurality of sets of array antennas by the directivity control unit, and corresponds to each transmission directivity and Z or reception directivity. The detection results detected by the signal intensity detection unit are compared for the received signals received in the same manner, and the detection results of the array antennas with the smallest variation in the detection results are compared among the plurality of sets of array antennas. The direction detection device according to any one of claims 18 to 21, wherein a direction corresponding to transmission directivity and Z or reception directivity at which the maximum value is detected as a direction of the wireless terminal.
[25] 前記方向検出部は、前記指向性制御部により前記複数組のアレイアンテナそれぞ れの送信指向性及び Z又は受信指向性を制御し、各送信指向性及び Z又は受信 指向性に対応して受信される受信信号について前記信号強度検出部により検出さ れる検出結果を平均し、該平均の最も大きなアレイアンテナにおいて前記検出結果 が最大値をとる送信指向性及び Z又は受信指向性に対応する方向を前記無線端末 の方向として検出するものである請求項 18から 21の何れかの方向検出装置。 [25] The direction detection unit controls the transmission directivity and Z or reception directivity of each of the plurality of sets of array antennas by the directivity control unit, and supports each transmission directivity and Z or reception directivity. The detection results detected by the signal intensity detection unit are averaged for the received signals received in response to the transmission directivity and Z or reception directivity at which the detection result has the maximum value in the array antenna having the largest average. The direction detecting device according to any one of claims 18 to 21, wherein a direction to be detected is detected as a direction of the wireless terminal.
[26] 前記アレイアンテナは、互いに平行を成すように配設された複数本の直線状アンテ ナ素子力も構成されるものである請求項 16から 25の何れかの方向検出装置。 26. The direction detection device according to claim 16, wherein the array antenna is also configured with a plurality of linear antenna element forces arranged so as to be parallel to each other.
[27] 前記アレイアンテナを構成する複数本の直線状アンテナ素子のうち、相互に最も離 れて配設された直線状アンテナ素子相互間の距離は、前記無線信号の搬送波の波 長以下である請求項 26の方向検出装置。 [27] Of the plurality of linear antenna elements constituting the array antenna, the distance between the linear antenna elements arranged farthest from each other is equal to or less than the wavelength of the carrier wave of the radio signal 27. The direction detection device according to claim 26.
[28] 前記複数組のアレイアンテナは、互いに平行を成すように配設された 3本の直線状 アンテナ素子のうち相互に隣接する 2本ずつの直線状アンテナ素子力 それぞれ構 成される 2組のアレイアンテナである請求項 26又は 27の方向検出装置。 [28] The plurality of sets of array antennas are composed of two sets of linear antenna element forces each adjacent to each other among three linear antenna elements arranged so as to be parallel to each other. The direction detection device according to claim 26 or 27, wherein the direction detection device is an array antenna.
[29] 前記複数組のアレイアンテナは、互いに平行を成すように配設された 3本の直線状 アンテナ素子のうち相互に隣接する 2本ずつの直線状アンテナ素子力 それぞれ構 成される 2組のアレイアンテナ、及び相互に最も離れて配設された 2本の直線状アン テナ素子力も構成される 1組のアレイアンテナである請求項 26又は 27の方向検出装 置。
[29] The plurality of sets of array antennas include two sets of two linear antenna element forces adjacent to each other among three linear antenna elements arranged so as to be parallel to each other. 28. The direction detection device according to claim 26 or 27, wherein the array antenna is a pair of array antennas, and the force of two linear antenna elements arranged farthest from each other is also configured.
[30] 前記複数組のアレイアンテナは、互いに平行を成すように配設された 4本の直線状 アンテナ素子のうち相互に隣接する 2本の直線状アンテナ素子力も構成される 3組の アレイアンテナである請求項 26又は 27の方向検出装置。 [30] The plurality of sets of array antennas includes three sets of array antennas that are configured by two linear antenna element forces adjacent to each other among four linear antenna elements arranged so as to be parallel to each other. The direction detection device according to claim 26 or 27.
[31] 前記複数組のアレイアンテナは、互いに平行を成すように配設された 4本の直線状 アンテナ素子のうち選択される何れか 3本の直線状アンテナ素子カゝら構成される 2組 のアレイアンテナである請求項 26又は 27の方向検出装置。 [31] The plurality of sets of array antennas include two sets of four linear antenna elements selected from four linear antenna elements arranged so as to be parallel to each other. The direction detection device according to claim 26 or 27, wherein the direction detection device is an array antenna.
[32] 前記方向検出部は、予め定められた所定の相対角度範囲に対応して前記指向性 制御部により前記複数組のアレイアンテナそれぞれの送信指向性及び Z又は受信 指向性を制御し、各送信指向性及び Z又は受信指向性に対応して受信される受信 信号を比較することで前記無線端末の方向を検出するものである請求項 17から 31 の何れかの方向検出装置。 [32] The direction detection unit controls the transmission directivity and Z or reception directivity of each of the plurality of sets of array antennas by the directivity control unit corresponding to a predetermined relative angle range determined in advance. 32. The direction detection device according to claim 17, wherein the direction of the wireless terminal is detected by comparing reception signals received corresponding to transmission directivity and Z or reception directivity.
[33] 前記複数組のアレイアンテナそれぞれにより送信あるいは受信を行った結果、受信 される受信信号を比較することで障害物の存在する方向を検出する障害物方向検 出部、又は予め障害物の方向が既知である場合はその障害物の方向を設定する障 害物方向設定部を備え、前記方向検出部は、該障害物方向検出部により障害物が 検出された方向、又は前記障害物方向設定部に設定された方向を除外して前記無 線端末の方向を検出するものである請求項 16から 32の何れかの方向検出装置。 [33] As a result of transmission or reception by each of the plurality of sets of array antennas, an obstacle direction detection unit that detects a direction in which an obstacle exists by comparing received received signals, or an obstacle in advance When the direction is known, an obstacle direction setting unit is provided for setting the direction of the obstacle. The direction detection unit is a direction in which the obstacle is detected by the obstacle direction detection unit, or the obstacle direction. The direction detection device according to any one of claims 16 to 32, wherein the direction of the wireless terminal is detected by excluding the direction set in the setting unit.
[34] 前記方向検出装置は、検出対象である無線タグに向けて所定の送信信号を送信 すると共に、該送信信号に応答して前記無線タグから返信される返信信号を受信す ることで前記無線タグの方向を検出する無線タグ方向検出装置である請求項 16から 33の何れかの方向検出装置。 [34] The direction detection device transmits a predetermined transmission signal toward the detection target wireless tag, and receives a reply signal returned from the wireless tag in response to the transmission signal. 34. The direction detection device according to claim 16, wherein the direction detection device is a wireless tag direction detection device that detects a direction of the wireless tag.
[35] 前記方向検出部は、前記送信信号の搬送波の周波数を変化させ、各周波数に対 応して受信される受信信号を比較することで前記無線タグの方向を検出するもので ある請求項 34の方向検出装置。
[35] The direction detection unit detects a direction of the wireless tag by changing a frequency of a carrier wave of the transmission signal and comparing a reception signal received corresponding to each frequency. 34 direction detection devices.
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JP2006-220698 | 2006-08-11 | ||
JP2006220699A JP5309432B2 (en) | 2006-08-11 | 2006-08-11 | Direction detection device |
JP2006220698A JP5233096B2 (en) | 2006-08-11 | 2006-08-11 | Direction detection device |
JP2006-220699 | 2006-08-11 |
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Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2012119979A (en) * | 2010-12-01 | 2012-06-21 | Denso Wave Inc | Variable directional antenna device |
JP2013113740A (en) * | 2011-11-29 | 2013-06-10 | Secom Co Ltd | Azimuth detection device of radio equipment |
Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH04309882A (en) * | 1991-04-08 | 1992-11-02 | Nippon Kouro Hiyoushiki Kyokai | Detection of response data of transponder |
JPH08103039A (en) * | 1994-09-30 | 1996-04-16 | Mitsubishi Electric Corp | Radio wave feeder apparatus |
JPH11186834A (en) * | 1997-12-24 | 1999-07-09 | Mitsubishi Electric Corp | Horn antenna system |
JP2001228235A (en) * | 2000-02-15 | 2001-08-24 | Toyota Motor Corp | Electromagnetic wave radiating device and radar device |
JP2005300219A (en) * | 2004-04-07 | 2005-10-27 | Fuji Photo Film Co Ltd | Radio tag, radio tag posture sensing device, and radio tag posture sensing system |
JP2005345198A (en) * | 2004-06-01 | 2005-12-15 | Brother Ind Ltd | Interrogator for wireless tag communication system and wireless tag communication system |
JP2006284510A (en) * | 2005-04-04 | 2006-10-19 | Brother Ind Ltd | Radio tag communication device |
JP2007033415A (en) * | 2005-07-29 | 2007-02-08 | Murata Mfg Co Ltd | Radar apparatus |
-
2007
- 2007-06-29 WO PCT/JP2007/063117 patent/WO2008018253A1/en active Application Filing
Patent Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH04309882A (en) * | 1991-04-08 | 1992-11-02 | Nippon Kouro Hiyoushiki Kyokai | Detection of response data of transponder |
JPH08103039A (en) * | 1994-09-30 | 1996-04-16 | Mitsubishi Electric Corp | Radio wave feeder apparatus |
JPH11186834A (en) * | 1997-12-24 | 1999-07-09 | Mitsubishi Electric Corp | Horn antenna system |
JP2001228235A (en) * | 2000-02-15 | 2001-08-24 | Toyota Motor Corp | Electromagnetic wave radiating device and radar device |
JP2005300219A (en) * | 2004-04-07 | 2005-10-27 | Fuji Photo Film Co Ltd | Radio tag, radio tag posture sensing device, and radio tag posture sensing system |
JP2005345198A (en) * | 2004-06-01 | 2005-12-15 | Brother Ind Ltd | Interrogator for wireless tag communication system and wireless tag communication system |
JP2006284510A (en) * | 2005-04-04 | 2006-10-19 | Brother Ind Ltd | Radio tag communication device |
JP2007033415A (en) * | 2005-07-29 | 2007-02-08 | Murata Mfg Co Ltd | Radar apparatus |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2012119979A (en) * | 2010-12-01 | 2012-06-21 | Denso Wave Inc | Variable directional antenna device |
JP2013113740A (en) * | 2011-11-29 | 2013-06-10 | Secom Co Ltd | Azimuth detection device of radio equipment |
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