JP4670440B2 - Management system, management system control method, information processing apparatus, management system control program, and recording medium recording management system control program - Google Patents

Description

  The present invention relates to an information processing device, a management system, a control method for the information processing device, a control program for the information processing device, and a recording medium on which the control program for the information processing device is recorded. It is about.

  In recent years, the use of RFID (Radio Frequency Identification) tags (wireless tags) has become widespread. RFID tags are expected to replace barcodes, especially in the field of logistics. For example, it is conceivable to detect RFID tags of packages to be transported at predetermined positions and manage the packages. ing. As such a system, for example, the following transport system is disclosed (see Patent Document 1).

  That is, the conveyance system of Patent Document 1 has an order information file that stores the identification IDs of RFID tags attached to the respective conveyance objects in accordance with the conveyance order. Then, in the transport line, the identification ID is received from each transported object to be transported, and the wireless tag to be identified is selected with reference to the stored order information file.

  In this transport system, since the transport object can be confirmed in the order information file, the current position of each object can be confirmed while confirming the order of the transport objects that have been transported.

  By the way, due to the directivity of the antenna provided in the reader / writer, a range that the reader / writer can detect exists over a predetermined area. For this reason, when a plurality of RFID tags are within the detection range, the reader / writer can obtain responses from all the RFID tags in the detectable range and accurately grasp the conveyance order of the conveyance objects. The problem of not being able to occur.

  Therefore, conventionally, for example, electromagnetic shields are provided before and after the reader / writer antenna so that only a predetermined range of RFID tags can be detected, and the arrangement direction of the antenna is adjusted. It is devised not to be.

In addition, in order to suppress the spread of radio waves transmitted and received between the RFID tag and the reader / writer and to effectively use scattered radio waves, a radio communication system that includes a radio wave reflector and prevents signal scattering has also been proposed. (Patent Document 2).
JP 2000-255716 A (published September 19, 2000) JP 2003-249872 A (published September 5, 2003)

  However, in the above conventional configuration, it is sufficient to prevent erroneous detection such that the radio wave from the reader / writer is reflected on the conveyance object itself or the conveyance equipment conveying the conveyance object, and an erroneous signal is received from the object not to be detected. The problem that cannot be prevented.

  More specifically, in the above-described conventional configuration, when an erroneous radio wave is received, such as by receiving a radio wave of an object outside the detection target area of the reader / writer, by a radio wave reflected by the transport target or transport equipment. It is not the structure that assumed.

  The present invention has been made in view of the above problems, and an object of the present invention is to control an information processing apparatus, a management system, and an information processing apparatus that can accurately specify the order of RFID tags passing through a predetermined position. A method, a control program for an information processing apparatus, and a recording medium on which the control program for the information processing apparatus is recorded.

  In order to solve the above-described problems, the information processing apparatus according to the present invention is located at different positions for transmitting and receiving radio waves with RFID tags attached to objects passing through a predetermined position in a line. An information processing device comprising a plurality of antennas arranged and receiving information from a tag communication device for calculating a distance between the antenna and the RFID tag based on radio waves received from the RFID tag received by each antenna. The distance information, which is the distance information calculated based on the radio wave from the RFID tag, is associated with the RFID tag information, and the receiving means for receiving from the tag communication device, and all the received distance information. And a specifying means for specifying the passing order of the RFID tag at a predetermined position.

  By the way, the tag communication device can measure the distance between each RFID tag and each antenna based on the radio wave received from each RFID tag. In addition, since each antenna provided in the tag communication device is arranged at a different position, even if an antenna placed at a certain position blocks the radio wave from the RFID tag due to an obstacle or the like, it is located at another position. The radio wave from the RFID tag can be received by another antenna provided.

  Therefore, the tag communication device can calculate the distance between the antenna and the RFID tag without failing to receive the radio wave of the RFID tag moving in a certain direction.

  Since the information processing apparatus according to the present invention includes a receiving unit, distance information between each antenna and the RFID tag can be acquired from each of the plurality of antennas included in the tag communication apparatus. That is, distance information from any one of the plurality of antennas to the RFID tag can be obtained for all the RFID tags moving in a certain direction.

  In addition, since the RFID tag moves in a certain direction, the relative positional relationship between the moving RFID tags is specified according to the distance between the RFID tag and the antenna. That is, in the information processing apparatus according to the present invention, the specifying unit can grasp the positional relationship of each RFID tag with respect to a predetermined position by comparing the distance information.

  For this reason, for example, even when there are a plurality of RFID tags in a communicable range of the tag communication device, the order of the RFID tags passing through a predetermined position can be specified.

  Therefore, the information processing apparatus according to the present invention has an effect that it is possible to accurately specify the passing order of the RFID tag at a predetermined position without providing a separate member such as an electromagnetic shield.

  In the information processing apparatus according to the present invention, in the configuration described above, whether or not each of the distance information received by the receiving unit is within a specified range in which the tag communication apparatus can directly communicate with the RFID tag. And determining means for excluding distance information determined by the determining means not being within a prescribed range from comparison targets for specifying the order of passage of RFID tags at a predetermined position. It is preferable to be configured.

  According to the said structure, since the determination means is provided, it can be determined whether each distance information received by the receiving means is in the said specified range.

  For example, the RFID tag in the case where the distance is not within a specified range includes those in which radio waves from the RFID tag are reflected by other things and received by the antenna of the tag communication device.

  As described above, the information processing apparatus according to the present invention can exclude the distance information that is not within the specified range from the comparison target for specifying the passing order at the predetermined position. It is possible to confirm the passing order of the predetermined positions only for the straight line distance.

  For this reason, the information processing apparatus according to the present invention can specify the passing order of the RFID tags at a predetermined position with high accuracy.

  In the information processing apparatus according to the present invention, in the configuration described above, a part of the plurality of antennas is selected, and the tag communication is performed so that the selected antenna can effectively transmit and receive radio waves with the RFID tag. You may comprise so that the instruction | indication means to instruct | indicate to an apparatus is provided.

  Since the information processing apparatus according to the present invention includes the above instruction means, the tag communication apparatus can select and switch an antenna that enables effective transmission / reception with the RFID tag from among a plurality of antennas. For this reason, it is possible to prevent radio waves transmitted and received with the RFID tag from interfering with each other between a plurality of antennas.

  Therefore, since the tag communication device can accurately calculate the position information based on the radio wave acquired by each antenna, the information processing device according to the present invention is an RFID tag that passes a predetermined position based on the accurate position information. The order of passing can be specified.

  Therefore, the information processing apparatus according to the present invention can specify the order of RFID tags passing through a predetermined position with high accuracy.

  In the information processing apparatus according to the present invention, in the configuration described above, when the reception unit has not received the distance information from the tag communication apparatus for a predetermined period, or all of the RFID tags that can receive radio waves. When the distance information is received, the switching instruction means is preferably configured to instruct antenna switching.

  According to the above configuration, it is possible to instruct switching of the antenna when the distance information is not received from the tag communication device for a predetermined period. For this reason, even when the radio wave cannot be received from the RFID tag by one antenna, the radio wave of the RFID tag can be received by the switched antenna. Further, since the antenna can be switched when the distance information of all the RFID tags is received, it is possible to prevent the generation of an RFID tag that cannot pick up radio waves and cannot obtain distance information.

  Therefore, the information processing apparatus according to the present invention can specify the order of RFID tags passing through a predetermined position with high accuracy.

  The information processing apparatus according to the present invention may further include an output unit that outputs information indicating the passing order of the RFID tag at a predetermined position specified by the specifying unit in the configuration described above.

  According to the above configuration, since the output unit is provided, information indicating the passing order of the RFID tag specified by the specifying unit at the predetermined position can be used.

  In order to solve the above-described problem, the management system according to the present invention receives radio waves from the above-described information processing apparatus and RFID tags attached to objects passing through a predetermined position in a row. The position calculation means for calculating the distance between the antenna and the RFID tag based on the plurality of antennas arranged at different positions and the radio wave from the RFID tag received by each antenna, and the position calculation means And a tag communication device having transmission means for transmitting the positional information to the information processing device.

  According to the above configuration, since the tag communication device includes a plurality of antennas arranged at different positions, it reliably receives radio waves from RFID tags attached to objects passing through a predetermined position in a line. can do.

  In addition, since the position calculation unit and the transmission unit are provided, the calculated distance information to each RFID tag can be provided to the information processing apparatus.

  Therefore, the management system according to the present invention produces an effect that the passing order of RFID tags passing through a predetermined position can be specified with high accuracy.

  In order to solve the above-described problem, a control method for an information processing device according to the present invention is configured to mutually transmit and receive radio waves with RFID tags attached to objects passing through a predetermined position in a line. An information processing apparatus that includes a plurality of antennas arranged at different positions and receives information from a tag communication apparatus that calculates the distance between the antenna and the RFID tag based on radio waves received from the RFID tags received by the antennas. Each of the distance information, which is the distance information calculated based on the radio wave from the RFID tag, is associated with the information of the RFID tag and received from the tag communication device; And comparing all the distance information and specifying the passing order of the RFID tags at a predetermined position.

  According to the above method, in the method for controlling the information processing apparatus according to the present invention, the distance information of each RFID tag can be received from the tag communication device by the step of receiving the distance information of the RFID tag. Further, in the step of specifying the passing order of the predetermined positions, the positional relationship of the RFID tags can be compared by comparing the distance information, and the passing order of the RFID tags at the predetermined positions can be specified.

  Therefore, the control method of the information processing apparatus has an effect that the passing order of the RFID tags passing through the predetermined position can be specified with high accuracy.

  In addition, each means with which the said information processing apparatus is provided may be implement | achieved by computer, and in this case, control of the information processing apparatus which implement | achieves the said information processing apparatus with a computer by operating a computer as said each means A computer-readable recording medium on which the program is recorded also falls within the scope of the present invention.

  In order to solve the above-described problems, the information processing apparatus according to the present invention is located at different positions for transmitting and receiving radio waves with RFID tags attached to objects passing through a predetermined position in a line. An information processing device comprising a plurality of antennas arranged and receiving information from a tag communication device for calculating a distance between the antenna and the RFID tag based on radio waves received from the RFID tag received by each antenna. The distance information, which is the distance information calculated based on the radio wave from the RFID tag, is associated with the RFID tag information, and the receiving means for receiving from the tag communication device, and all the received distance information. And a specifying means for specifying the passing order of the RFID tag at a predetermined position.

  Therefore, the information processing apparatus according to the present invention has an effect that it is possible to accurately specify the passing order of the RFID tag at a predetermined position without providing a separate member such as an electromagnetic shield.

  In order to solve the above-described problem, the management system according to the present invention receives radio waves from the above-described information processing apparatus and RFID tags attached to objects passing through a predetermined position in a row. The position calculation means for calculating the distance between the antenna and the RFID tag based on the plurality of antennas arranged at different positions and the radio wave from the RFID tag received by each antenna, and the position calculation means And a tag communication device having transmission means for transmitting the positional information to the information processing device.

  Therefore, the management system according to the present invention produces an effect that the passing order of RFID tags passing through a predetermined position can be specified with high accuracy.

  In order to solve the above-described problem, a control method for an information processing device according to the present invention is configured to mutually transmit and receive radio waves with RFID tags attached to objects passing through a predetermined position in a line. An information processing apparatus that includes a plurality of antennas arranged at different positions and receives information from a tag communication apparatus that calculates the distance between the antenna and the RFID tag based on radio waves received from the RFID tags received by the antennas. Each of the distance information, which is the distance information calculated based on the radio wave from the RFID tag, is associated with the information of the RFID tag and received from the tag communication device; And comparing all the distance information and specifying the passing order of the RFID tags at a predetermined position.

  Therefore, the control method of the information processing apparatus has an effect that the passing order of the RFID tags passing through the predetermined position can be specified with high accuracy.

  An embodiment of the present invention will be described below with reference to FIGS. In other words, the management system 90 according to the present embodiment confirms the transport order of the packages transported by the transport belt and manages each package. In this management system 90, as shown in FIG. 2, the RFID tag 1 is provided for each package, and each package is arranged on a transport belt and passes through a gate 80.

  The gate 80 includes gate legs 81a and 81b disposed at both ends in the width direction of the conveyor belt. The gate leg 81a is provided with an antenna 30a, and the gate leg 81b is provided with an antenna 30b. ing.

  In the present embodiment, the tag response signal from the RFID tag 1 of the package that has entered the vicinity of the gate 80 is read via the antenna 30a or the antenna 30b, and the package transfer order is determined. The width direction of the transport belt is a direction perpendicular to the transport direction.

  The configuration of the management system 90 according to the present embodiment will be described below with reference to FIG. FIG. 3 is a block diagram showing a main configuration of the management system 90 according to the present embodiment.

  The management system 90 according to the present embodiment is configured to include the reader / writer 2, the management device 10, and the management server 20. The reader / writer 2 communicates with the RFID tag 1 provided in the package.

  The RFID tag 1 is attached to various articles, and stores information relating to the attached article or an article or person related thereto. The RFID tag 1 includes a wireless communication IC (Integrated Circuit), a storage unit such as an IC chip, and a tag antenna. In the present embodiment, the RFID tag 1 does not have a power source such as a battery, and a passive RFID that performs wireless communication with the reader / writer 2 by operating a circuit with power transmitted by radio waves from the reader / writer 2. It is assumed that tags will be used. The RFID tag used in the present embodiment is not limited to the passive RFID tag as described above, and may be an active RFID tag having a power source such as a battery.

  The reader / writer 2 is a device that performs wireless communication with each RFID tag 1 and reads / writes information stored in the RFID tag 1. In the present embodiment, the reader / writer 2 reads and writes information stored in the RFID tag 1, but the present invention is not limited to this, and the information stored in the RFID tag 1 is read. It may be an RFID reader that performs only the above.

  In this embodiment, the frequency band of the radio wave transmitted and received by the reader / writer 2 is a so-called UHF band of about 800 MHz to 960 MHz. By using radio waves in such a frequency band, the reader / writer 2 can communicate with the RFID tag 1 located within a distance range of several meters to several tens of meters. In the present embodiment, communication using the UHF band is assumed. However, the present invention is not limited to this, and the 13.56 MHz band, 2.45 GHz band, and the like as frequency bands for RFID tags are used. A frequency band may be used, and further, communication using another frequency band capable of performing wireless communication may be performed.

  Further, the transmission antennas 3a and 3b and the reception antennas 4a and 4b provided in the reader / writer 2 are arranged on the gate legs 81a and 81b of the gate 80, respectively. It is assumed that an antenna configured by a combination of the transmission antenna 3a and the reception antenna 4a is 30a, and an antenna configured by a combination of the transmission antenna 3b and the reception antenna 4b is an antenna 30b. In addition, when it is not necessary to distinguish between the antenna 30a and the antenna 30b, the antenna 30 is referred to. The detailed configuration of the reader / writer 2 will be described later.

  In addition, the management device 10 specifies the package that has passed through the gate 80 based on the distance to the RFID tag 1 calculated by the reader / writer 2. A detailed configuration of the management apparatus 10 will also be described later.

  The management server 20 records packages that have passed through the gate 80. In other words, the management system 90 according to the present embodiment is configured such that when the management apparatus 10 identifies a package that has passed through the gate 80, information on the identified package is transmitted to the management server 20. The package information is transmitted from the management apparatus 10 to the management server 20 according to the order in which the packages are transported. For this reason, the management server 20 can record and manage information relating to the packages in the order in which the packages are transported.

(Configuration of reader / writer)
First, the configuration of the reader / writer 2 will be described below with reference to FIG.

  The reader / writer 2 includes transmission antennas 3a and 3b, reception antennas 4a and 4b, a communication processing unit 5, a position measurement unit (position information calculation means) 6, and an external communication unit 7. Note that the transmission antenna 3a and the transmission antenna 3b are referred to as the transmission antenna 3 when it is not necessary to distinguish between them. Similarly, the receiving antenna 4a and the receiving antenna 4b are referred to as the receiving antenna 4 when it is not necessary to distinguish between them.

  The transmission antenna 3 is an antenna that transmits radio waves to the RFID tag 1, and the reception antenna 4 is an antenna that receives radio waves transmitted from the RFID tag 1. The transmission antenna 3 and the reception antenna 4 are configured by, for example, a patch antenna or an array antenna.

  The communication processing unit 5 is a block that performs various controls related to communication between the reader / writer 2 and the RFID tag 1 according to the present embodiment. Specifically, the communication processing unit 5 performs processing such as modulation and amplification of the transmission signal transmitted from the transmission antenna 3, and performs processing such as amplification and demodulation of the reception signal received by the reception antenna 4. To do.

  The communication processing unit 5 is also a block that performs read and write control of information with respect to the RFID tag 1 to be communicated via the transmission antenna 3 and the reception antenna 4. That is, the communication processing unit 5 transmits a signal ((R / W request signal) indicating a command instruction such as reading and writing to the RFID tag 1 via the transmission antenna 3. The communication processing unit 5 The signal (tag response signal) from the RFID tag 1 is received via the receiving antenna 4.

  Note that the reading and / or writing control of information with respect to the RFID tag 1 is executed in accordance with an instruction received from the management device 10 via the external communication unit 7.

  In addition, the communication processing unit 5 separates the received signal into an I signal and a Q signal and inputs them to the position measuring unit 6, thereby enabling phase detection processing in the position measuring unit 6. .

  The position measuring unit 6 is a block that measures the position of the RFID tag 1 based on the received signal received from the RFID tag 1. Although details will be described later, the position of the RFID tag 1 is measured by measuring the distance between the reader / writer 2 and the RFID tag 1, measuring the direction of the RFID tag 1 when viewed from the reader / writer 2, and the RFID tag 1. Measurement of the spatial position.

  Strictly speaking, the distance between the reader / writer 2 and the RFID tag 1 is the distance between the transmission antenna 3 in the reader / writer 2 and the RFID tag antenna included in the RFID tag 1 and the RFID tag antenna included in the RFID tag 1. Equivalent to the average of the distances between the antenna and the receiving antenna 4. When the RFID tag 1 is an active type, this corresponds to the distance between the receiving antenna 4 and the RFID tag antenna included in the RFID tag 1.

  The external communication unit 7 is a block that transmits information on the RFID tag 1 read by the reader / writer 2 to the management apparatus 10 and receives write information on the RFID tag 1 from the management apparatus 10. The management device 10 and the external communication unit 7 are connected to each other by wire, but may be configured to be connected wirelessly. In addition, the management device 10 that operates based on the read / write processing of the RFID tag 1 by the reader / writer 2 may be configured to incorporate the reader / writer 2.

(Configuration for distance measurement)
Next, an example of a configuration for measuring the distance between the RFID tag 1 and the reader / writer 2 in the reader / writer 2 will be described with reference to FIG. As shown in the figure, the communication processing unit 5 includes a PLL (Phase Locked Loop) unit 5A, a modulation unit 5B, a power amplification unit 5C, an amplification unit 5D (amplification unit 5D1, amplification unit 5D2), and a frequency as frequency adjustment units. A conversion unit 5E (5E1, 5E2, 90 ° phase unit 5E3), a controller unit 5F, an antenna switch 5H, and a distributor 5I are provided. The position measurement unit 6 includes a phase information acquisition unit 6A and a distance calculation unit 6B.

  In the communication processing unit 5, the PLL unit 5A is a block for setting a carrier frequency of a transmission signal transmitted from the transmission antenna 3, and is configured by a PLL circuit. The modulation unit 5B performs a process of modulating the carrier signal generated by the PLL unit 5A and superimposing data on the transmission signal.

  In the present embodiment, the modulation unit 5B generates a transmission signal by ASK (Amplitude Shift Keying) modulation. Note that the transmission signal modulation method is not limited to the above ASK modulation, and other digital modulation methods such as FSK (Frequency Shift Keying) modulation and PSK (Phase Shift Keying) modulation may be adopted. . The power amplifier 5C is a block that amplifies the transmission signal.

  The amplifying unit 5D is a block that amplifies the received signal received by the receiving antenna 4. The frequency converting unit 5E is a block that performs processing for converting the frequency of the reception signal amplified by the amplifying unit 5D and converting it to a lower frequency signal. The amplification unit 5D includes an amplification unit 5D1 and an amplification unit 5D2. The frequency converter 5E includes mixers 5E1 and 5E2 and a 90 ° phase shifter 5E3.

  That is, the received signal received by the receiving antenna 4 is sent to the distributor 5I, and the distributor 5I branches the received signal into two paths. One of the branched received signals is input to the amplifying unit 5D1, and the other is input to the amplifying unit 5D2. The amplifying unit 5D1 amplifies the input received signal and inputs it to the mixer 5E1. Similarly, the amplifying unit 5D2 amplifies the received signal and inputs it to the mixer 5E2.

  The mixer 5E1 outputs an I signal by adding the reception signal input from the amplification unit 5D1 and the carrier signal output from the PLL unit 5A, and inputs this I signal to the phase information acquisition unit 6A. The mixer 5E2 adds the Q signal by adding the reception signal input from the amplification unit 5D2 and the carrier signal output from the PLL unit 5A and whose phase is changed by 90 ° via the 90 ° phase shift unit 5E3. The Q signal is output to the phase information acquisition unit 6A.

  The controller unit 5F is a block that controls the frequency of the carrier signal set by the PLL unit 5A. The controller unit 5F is also a block for inputting data to be modulated to the transmission signal to the modulation unit 5B. Furthermore, the controller unit 5F is also a block that performs a process of receiving the distance information calculated by the distance calculation unit 6B.

  The antenna switch 5H communicates with the RFID tag 1 by a combination of the transmission antenna 3a and the reception antenna 4a (antenna 30a), or is combined with the RFID tag 1 by a combination of the transmission antenna 3b and the reception antenna 4b (antenna 30b). Whether to perform communication or to switch the antenna 30 for communication. The antenna switch 5H switches the antenna 30 that can communicate with the RFID tag 1 in response to an antenna switching instruction from the controller unit 5F.

  The distributor 5I is for distributing the received signal to two circuits, and this distributor 5I distributes the received signal to the amplifying unit 5D1 and the amplifying unit 5D2.

  In the position measurement unit 6, the phase information acquisition unit 6A is a block that detects the amount of phase shift of the received signal frequency-converted by the frequency conversion unit 5E and acquires this as phase shift amount information. The distance calculation unit 6B is a block that calculates the distance between the RFID tag 1 and the reader / writer 2 based on information on the amount of phase displacement acquired by the phase information acquisition unit 6A. An example of this distance calculation method will be described below with reference to FIGS. 5 (a) to 5 (c) and FIG.

  In the reader / writer 2 according to the present embodiment, the transmission antenna 3 and the reception antenna 4 are provided separately, but a configuration in which one antenna has functions of both the transmission antenna 3 and the reception antenna 4 is used. Also good.

  In the case of a configuration in which one antenna is used as having both functions of the transmission antenna 3 and the reception antenna 4, in FIG. 4, between the power amplification unit 5C and the antenna switch 5H, and between the distributor 5I and the antenna switch 5H, This can be realized by providing a circulator (not shown) between the two.

  That is, the circulator controls the direction of the RF signal of the UHF, and the input from the power amplifier 5C is transmitted to the antenna 30 side via this circulator, and the signal from the antenna side (tag response signal) Is output to the distributor 5I through this circulator.

(Details of distance measurement)
In the present embodiment, the reader / writer 2 transmits an R / W request signal (request signal) to the RFID tag 1, and the RFID tag 1 returns a tag response signal accordingly. This state is shown in FIGS. 5 (a) to 5 (c).

  While the reader / writer 2 always transmits a specific signal, when requesting the RFID tag 1 to transmit a tag response signal, as shown in FIG. The requested R / W request signal is transmitted.

  That is, the controller unit 5F in the reader / writer 2 controls the modulation unit 5B to transmit data indicating the steady state in the steady state, and when requesting the tag response signal, the data constituting the R / W request signal. The modulation unit 5B is controlled so as to transmit.

  The RFID tag 1 constantly monitors the signal sent from the reader / writer 2 and, when detecting that the R / W request signal has been received, transmits the tag response signal in response to the signal.

  As shown in FIG. 5C, the tag response signal includes a preamble part and a data part. The preamble portion indicates data indicating the start of a tag response signal, and is predetermined data common to all RFID tags 1 within the same standard (for example, EPC). The data part is transmitted subsequent to the preamble part, and indicates data indicating substantial information transmitted from the RFID tag 1. Examples of the information included in the data part include ID information unique to each RFID tag 1. Information to be transmitted from the RFID tag 1, for example, various information stored in the storage part in the RFID tag 1. Etc. may be included.

The reader / writer 2 transmits the R / W request signal twice, and makes the carrier frequencies used for transmitting each R / W request signal different from each other. That is, the controller unit 5F in the reader writer 2, when transmitting the first R / W request signal, and controls the PLL section 5A to output the carrier signal at a first frequency f _1, 2 nd R / W When the request signal is transmitted, the PLL unit 5A is controlled so that the carrier signal is output at the second frequency f ₂ different from the _first frequency f ₁ . This state is shown in FIG.

As shown in the figure, when the first R / W request signal transmitted at the frequency f ₁ RFID tag 1 receives the tag response signal is returned again in the first frequency f _1. Then, the reader / writer 2 detects φ ₁ indicating the amount of change in the phase of the tag response signal by analyzing the preamble portion of the tag response signal received by the phase information acquisition unit 6A. Similarly, when the second R / W request signal transmitted at the frequency f ₂ RFID tag 1 receives the tag response signal is returned again at the second frequency f _2. Then, the reader-writer 2, by analyzing the preamble portion of the tag response signal phase information acquiring section 6A receives, detects the phi ₂ showing the phase change amount of the tag response signal.

  In the above example, the amount of change in the phase of the tag response signal is detected by analyzing the preamble part. However, the present invention is not limited to this, and the phase change including the data part is also included. The amount of change may be detected, or the amount of phase change may be detected in the data portion. However, when the modulation method is PSK, it is difficult to detect the amount of change in phase with distance based on the data part whose contents can change. Therefore, in the preamble part whose contents are fixed, It is preferable to detect the amount of change.

  The reader / writer 2 is set to detect the amount of change in phase every 50 msec in this embodiment. That is, the reader / writer 2 transmits the R / W request signal twice to the RFID tag 2 at intervals of 50 msec. The timing of detecting the phase change amount is not limited to the 50 msec interval, and may be a shorter time interval or a longer time interval. It is preferable to determine appropriately according to the moving speed of the article and the communicable range of the reader / writer 2.

As described above, when the phase information acquiring section 6A detects a change amount phi ₁ and phi ₂ of the phase information of the amount of change in the phase is transmitted to the distance calculation section 6B. Distance calculation section 6B, based on the phi ₁ and phi _2, is calculated as follows distance between the RFID tag 1 and the reader-writer 2.

First, assuming that the distance r from the receiving antenna 4 to the RFID tag 1 is a distance r, a phase change caused by a signal carried by the first frequency f ₁ and the second frequency f ₂ propagating the distance of the round trip 2r. The quantities φ ₁ and φ ₂ are expressed by the following equations.

  In the above formula, c represents the speed of light. Based on the above two formulas, the distance r is obtained by the following formula.

As described above, the distance r from the receiving antenna 4 to the RFID tag 1 can be obtained based on the phase change amounts φ ₁ and φ ₂ . In the RFID tag 1, it is expected that a phase shift will occur between the reception of the R / W request signal and the transmission of the tag response signal. This phase shift is caused by the first frequency f _1. and it becomes even the same amount in both of the signal carried by the second frequency f _2. Therefore, the phase shift that occurs during signal transmission / reception in the RFID tag 1 does not affect the calculation of the distance.

  Further, as described above, the reader / writer 2 is configured to transmit the R / W request signal twice to the RFID tag 1 at 50 msec intervals. Therefore, the reader / writer 2 can measure the distance between the RFID tag 1 and its own device every 50 msec.

  In Equation 2, when Δφ is 2π or more, the distance r cannot be calculated accurately. That is, the maximum value rmax of the distance r that can be measured is when Δφ = 2π, and is represented by the following equation.

Here, for example, when the difference between the first frequency f ₁ and the second frequency f ₂ is 5 MHz, the maximum distance rmax is 30 m from Equation 3. Similarly, when the difference between the first frequency f ₁ and the second frequency f ₂ is 2 MHz, the maximum distance rmax is 75 m from Equation 3. In the case of using the UHF band, the assumed maximum communication distance is about 10 m, and it can be seen that the above measurement has no practical problem.

  When the width of the gate 80 where the user enters and exits (the distance between the gate leg 81a and the gate leg 81b) is increased and the measurement of the maximum distance rmax or more is required, for example, the reception intensity of the received signal is increased. By using the measurement together, it is possible to measure the distance r.

  Specifically, when Δφ may be 2π or more, the candidate r ′ for the distance r is r ′ = r + n · rmax (n is an integer of 0 or more). Therefore, it is possible to specify the value of n by using the fact that the reception intensity of the reception signal decreases as the distance r increases.

  Note that the measurement methods shown in the above-mentioned “configuration related to distance measurement” and “details of distance measurement” are examples for measuring the distance between the reader / writer 2 and the RFID tag 1, and the reader / writer according to the present embodiment. The configuration of 2 is not limited to this. That is, the reader / writer 2 only needs to be configured to be able to measure the distance between the device itself and the RFID tag 1 from the signal received from the RFID tag 1.

  In addition, when an active type RFID tag is used, the distance is measured based on the tag response signal actively sent from the RFID tag 1 side without sending the R / W request signal from the reader / writer 2 side. You may come to do.

  Details of the reception process and the distance r calculation process performed in the above configuration will be described below.

Signal received distance propagated in the reader writer 2 of reciprocating 2r, when the frequency of the carrier signal f _1, is expressed by the following equation.

In the above equation, t is time, s ₁ (t) is the state of the signal transmitted by the carrier signal of frequency f ₁ , D (t) is the baseband signal when ASK modulation is performed in the modulator 5B, A Represents the amplitude of the carrier signal itself, and φ ₁ represents the amount of change in phase due to propagation through the distance of 2r round-trip. In this case, I ₁ (t) indicating the state of the I signal output by the mixer 5E1 and Q ₁ (t) indicating the state of the Q signal output by the mixer 5E2 are expressed by the following equations.

From the above, based on the I signal and the Q signal, the signal phase change φ ₁ due to the carrier signal having the frequency f ₁ can be obtained by the following equation.

Similarly, the amount of signal phase change φ ₂ due to the carrier signal of frequency f ₂ can be obtained by the following equation.

As described above, the phase information acquiring section 6A, based on the input I signal and Q signal, and acquires the change amount phi ₁ and phi ₂ phases. Then, the distance calculation unit 6B calculates the distance r by the following formula.

(Management device configuration)
Next, the configuration of the management apparatus 10 will be described with reference to FIG. 1 again.

  As shown in FIG. 1, the management device 10 according to the present embodiment includes an external communication unit 11, a detection determination unit 12, a switching instruction unit 13, an information storage unit 14, an order determination unit 15, and an output unit 16. Yes.

  The external communication unit 11 is a block for transmitting / receiving information to / from the reader / writer 2. For example, the external communication unit 11 receives information on the RFID tag 1 read by the reader / writer 2, or information indicating an instruction to the reader / writer 2. Or send. The external communication unit 11 transmits the information received from the reader / writer 2 to the detection determination unit 12. The external communication unit 11 transmits information for instructing switching of the antenna 30 to the reader / writer 2 in accordance with an instruction from the switching instruction unit 13.

  The detection determination unit 12 determines the presence / absence of detection of the RFID tag 1 based on information received from the reader / writer 2 via the external communication unit 11, or the distance r from the RFID tag 1 to which the detection is confirmed to the antenna 30. Information is obtained.

  When the detection determination unit 12 cannot confirm the detection of the RFID tag 1 for a predetermined time, the detection determination unit 12 notifies the switching instruction unit 13 to that effect. The detection determination unit 12 also notifies the switching instruction unit 13 when the distance between the RFID tag 1 and the antenna 30 whose detection has been confirmed is not within the specified range.

  In addition, this detection regulation range is a range prescribed | regulated in the distance range to the antenna 30a from the range through which the RFID tag 1 can pass in the gate 80, and in this embodiment, it is between RFID tag 1 and the reader / writer 2. The maximum communicable distance between them is set as the detection specified range. The maximum communicable distance is a range in which the antenna 30 can communicate with the RFID tag 1 as shown in FIG.

  However, this detection regulation range is not limited to this, the directivity of the antenna 30 of the reader / writer 2, the maximum distance for wireless communication, the distance between the gate leg 81 a and the gate leg 81 b in the gate 80, etc. It is preferable to be determined according to

  The switching instruction unit 13 is a block that instructs the reader / writer 2 to control via the external communication unit 11. The switching support unit 13 instructs the reader / writer 2 to select the antenna 30 that can communicate with the RFID tag 1 and switch to the selected antenna 30 in response to the notification from the detection determination unit 12. .

  The information storage unit 14 is a readable / writable storage medium, and stores first tag information 17 and second tag information 18. The first tag information 17 and the second tag information 18 are information on the RFID tag 1 within the detection regulation range among the detected RFID tags 1 and the distance r between the RFID tag 1 and the antenna 30. This information is associated with the information.

  In the present embodiment, the first tag information 17 is information on the distance r calculated based on the tag response signal received by the antenna 30a and information on the RFID tag 1 that has transmitted the tag response signal. The second tag information 18 is information on the distance r calculated based on the tag response signal received by the antenna 30b and information on the RFID tag 1 that has transmitted the tag response signal.

  The order determination unit 15 is a block that compares the size of the distance r between the RFID tag 1 and the antenna 30 in the information of the RFID tag 1 stored in the information storage unit 14. The order determination unit 15 reads the first tag information 17 and the second tag information 18 stored in the information storage unit 14 in accordance with an instruction from the detection determination unit 12 and compares the magnitudes of the distance r. . Then, as a result of the comparison, the order determination unit 15 reads the information of the RFID tag 1 from the information storage unit 14 in order from the one where the distance r becomes smaller, and passes it to the output unit 16.

  The output unit 16 is for outputting information to the management server 20. When receiving the information of the RFID tag 1 from the order determination unit 15, the output unit 16 transmits the information to the management server 20 in the order received.

(RFID tag reception timing)
Here, the reception timing of the RFID tag 1 by the reader / writer 2 in the management system 90 according to the present embodiment will be specifically described with reference to FIGS. 7 (a) and 7 (b).

  First, as a premise, in the present embodiment, as shown in FIG. 7A or FIG. 7B, the packages are transported one by one in the transport direction by the transport belt. Further, it is assumed that the package to be transported is provided with the RFID tag 1 at the side portion of the package. Further, gate legs 81a and 81b are provided at both ends of the transport belt at predetermined positions in the package transport path, and the gate legs 81a and 81b are provided with antennas 30a and 30b, respectively.

  In the present embodiment, the antenna 30a and the antenna 30b are set to switch the antenna 30 that can communicate with the RFID tag 1 at a predetermined time interval.

  Under such a premise, it is assumed that two RFID tags 1α and RFID tags 1β continuously enter the communicable range of the antenna 30a and the antenna 30b as shown in FIG. At this time, if the antenna 30b is communicable, the RFID tag 1α is detected by the antenna 30b. On the other hand, it is assumed that the RFID tag 1β is not detected because communication between the RFID tag 1β and the antenna 30b is blocked by the package to be conveyed.

  Conversely, in the state shown in FIG. 7A, assuming that the antenna 30a is communicable, the RFID tag 1β is detected by the antenna 30a. On the other hand, it is assumed that the RFID tag 1α is not detected because the communication between the RFID tag 1α and the antenna 30a is blocked by the package to be conveyed.

  Therefore, in the state shown in FIG. 7A, when the antenna that can communicate from the antenna 30b to the antenna 30a is switched as described above, the RFID tag 1 can be detected in the order of the RFID tag 1α and the RFID tag 1β. it can.

  On the other hand, if the antenna 30a is communicable in the state shown in FIG. 7A, the RFID tag 1β is detected first by the antenna 30a. Here, it is assumed that the antenna capable of communication from the antenna 30a to the antenna 30b is switched. In this case, the RFID tag 1α is detected by the antenna 30b. Therefore, when the antenna that can communicate with the RFID tag 1 is switched from the antenna 30b to the antenna 30a in this way, the RFID tag 1 is detected in the order of the RFID tag 1β and the RFID tag 1α.

  Next, as shown in FIG. 7B, it is assumed that three RFID tags 1 (RFID tags 1α, 1β, and 1γ) are continuously placed in the communicable range of the antenna 30a and the antenna 30b.

  If it is assumed that the antenna 30b can communicate at this time, the RFID tag 1α is detected by the antenna 30b. On the other hand, it is assumed that the RFID tag 1β and the RFID tag 1γ are not detected because communication between the RFID tag 1β and the RFID tag 1γ and the antenna 30b is interrupted by the transported luggage itself.

  Conversely, in the state shown in FIG. 7B, assuming that the antenna 30a is communicable, the RFID tag 1β and the RFID tag 1γ are detected by the antenna 30a. On the other hand, it is assumed that the RFID tag 1α is not detected because communication between the RFID tag 1α and the antenna 30a is blocked by the package itself including the RFID tag 1α.

  Therefore, in the state shown in FIG. 7B, when the antenna that can communicate from the antenna 30b to the antenna 30a is switched, the RFID tag 1β and the RFID tag 1γ are detected after the RFID tag 1α is detected. In this case, with respect to the order of the packages to be transported (the order of RFID tag 1α, RFID tag 1β, RFID tag 1γ), the order of detected RFID tag 1 is RFID tag 1β and RFID tag 1γ after RFID tag 1α. Are detected at the same time.

  On the other hand, assuming that the antenna 30a can communicate in the state shown in FIG. 7B, the RFID tag 1β and the RFID tag 1γ are detected by the antenna 30a. Here, it is assumed that the antenna capable of communication from the antenna 30a to the antenna 30b is switched. In this case, the RFID tag 1α is detected by the antenna 30b. Therefore, when the antenna capable of communicating with the RFID tag 1 is switched from the antenna 30b to the antenna 30a in this way, the RFID tag 1α is detected after the RFID tag 1β and the RFID tag 1γ are simultaneously detected.

  As described above, the order of the RFID tags 1 detected by the antenna 30 that can communicate with the RFID tag 1 and the attachment position of the RFID tag 1 of the package that comes within the communicable range is the package to be transported. It will be different from the order.

  Accordingly, a process for specifying the order of transporting the packages when the packages are transported as shown in FIG. 7A (transport order specifying process) will be described below with reference to FIGS.

(Transport order identification process)
First, as described above, the reader / writer 2 in the management system 90 according to the present embodiment includes the antenna 30a that can communicate with the RFID tag 1 until the package enters the communicable range of the reader / writer 2. And the antenna 30b are alternately switched.

  That is, in the management apparatus 10, the detection determination unit 12 monitors whether or not information (including distance information) of the RFID tag 1 has been received. When the information is not received from the reader / writer 2 for a predetermined time, the detection determination unit 12 instructs the reader / writer 2 to switch the antenna 30 that communicates with the RFID tag 1.

  First, in the state where the antenna 30a is switched in the reader / writer 2 so as to be communicable with the RFID tag 1 (step S11, hereinafter referred to as S11), the management apparatus 10 within the predetermined time Whether or not 1 is detected is determined (S12).

  Note that the predetermined time is a time set by the user, and is appropriately determined in consideration of the transport speed of the package, the size of the package being transported, the communicable range of the antenna 30, and the like. The determination of whether or not the RFID tag 1 is detected is not limited to the predetermined time, and may be after one sequence corresponding to the R / W request signal or after a predetermined number of times. The sequence according to the R / W request signal is a sequence from the reader / writer 2 receiving a reply from the RFID tag 1 according to the R / W request signal transmitted from the reader / writer 2 to the RFID tag 1. It is processing of. Then, the presence or absence of detection of the RFID tag 1 may be confirmed until this processing is completed once, or the presence or absence of detection of the RFID tag 1 is confirmed until this processing is completed a predetermined number of times. May be.

  In the determination of whether or not the RFID tag 1 is detected, if the management device 10 confirms the detection of the RFID tag 1 within a predetermined time (“YES” in S12), the management device 10 detects the detected RFID tag 1 It is determined whether it is within the specified range (S13).

  The RFID tag 1 detected here is referred to as an RFID tag 1a for convenience of explanation. A distance r between the antenna 30a and the RFID tag 1a is referred to as a distance r1a.

  That is, in the reader / writer 2, the position measuring unit 6 measures the distance r1a from the antenna 30a to the RFID tag 1a based on the tag response signal received from the RFID tag 1a. Then, the communication processing unit 5 transmits information on the RFID tag 1 a including information on the measured distance r 1 a to the management device 10 via the external communication unit 7.

  In the management apparatus 10, when the detection determination unit 12 receives the information of the RFID tag 1 a from the reader / writer 2 via the external communication unit 11, the detection determination unit 12 confirms the detection of the RFID tag 1.

  On the other hand, when the period during which the information of the RFID tag 1 is not received from the reader / writer 2 continues for a predetermined time (in the case of “NO” in S12), in the management device 10, the detection determination unit 12 instructs the switching instruction unit 13 to It is notified that the RFID tag 1 is not detected continuously for a predetermined time. In response to this notification, the switching instruction unit 13 instructs the reader / writer 2 to select the antenna 30b as an antenna that can communicate with the RFID tag 1 and to switch from the antenna 30a to the antenna 30b ("2 ”, See FIG. 9).

  For example, if the antenna is set to be switched after the end of one sequence instead of the predetermined time, a tag response signal is sent from the RFID tag 1 according to the R / W request signal from the reader / writer 2. If the signal cannot be received, the antenna 30 is immediately switched.

  On the other hand, when the RFID tag 1a is detected within a predetermined time, the detection determination unit 12 determines whether the distance to the RFID tag 1a is within the detection regulation range based on the information of the RFID tag 1a received from the reader / writer 2. Determine whether or not.

  Here, when the detection determination unit 12 determines that the RFID tag 1 a is not within the detection regulation range (in the case of “NO” in S <b> 13), in the management device 10, the detection determination unit 12 instructs the switching instruction unit 13. The detected distance to the RFID tag 1a is not within the detection rules. In response to this notification, the switching instruction unit 13 instructs the reader / writer 2 to switch the antenna communicable with the RFID tag 1 from the antenna 30a to the antenna 30b (proceed to "2", see FIG. 9). ).

  That is, when the detection determination unit 12 determines that the RFID tag 1a is not within the detection range for a predetermined time, the information regarding the RFID tag 1a is not stored in the information storage unit 14, and the switching instruction unit 13 is not stored. On the other hand, it notifies that the detected distance to the RFID tag 1a is not within the detection regulations.

  The RFID tag 1 that is detected by the reader / writer 2 but not within the detection regulation range is reflected by, for example, surrounding equipment such as the gate 80 or the package itself that is to be transported, and the tag response signal is reflected by the antenna 30a. The RFID tag 1 that reaches the center, such as the RFID tag 1 that is far from the gate 80 on the conveyor belt, or the RFID tag 1 that is on another conveyor belt.

  For this reason, in the present embodiment, information other than information on the RFID tag 1 whose distance information r is within the detection regulation range, that is, the RFID tag 1 whose tag response signal is transmitted directly to the antenna 30a but not reflected is the order of conveyance. It is configured not to be used specifically.

  On the other hand, when the detection determination unit 12 determines that the distance r1a to the RFID tag 1a is within the detection regulation range ("YES" in S13), the information of the distance r1a and the RFID tag 1a is associated with each other, It memorize | stores in the information storage part 14 as the 1st tag information 17 (S14).

  When the detection determination unit 12 associates the information of the distance r1a and the RFID tag 1a with the information storage unit 14 and stores them as the first tag information 17, the detection instruction unit 12 sets an antenna that can communicate with the RFID tag 1 to the switching instruction unit 13. Then, notification of switching from the antenna 30a to the antenna 30b is performed. In response to this notification from the detection determination unit 12, the switching instruction unit 13 instructs the reader / writer 2 to switch antennas via the external communication unit 11.

  On the other hand, when the reader / writer 2 receives the instruction from the management apparatus 10 via the external communication unit 7, the communication processing unit 5 switches the antenna that can communicate with the RFID tag 1 from the antenna 30a to the antenna 30b. To control.

  In this way, the antenna capable of communicating with the RFID tag 1 is switched from the antenna 30a to the antenna 30b (S15).

  In a state where the antenna 30b can communicate with the RFID tag 1, the detection determination unit 12 in the management device 10 determines whether or not another RFID tag 1 is detected within a predetermined time (S16). That is, the detection determination unit 12 determines whether or not another RFID tag 1 different from the RFID tag 1a detected in step S12 is detected. If the detection determination unit 12 determines that no other RFID tag 1 has been detected within a predetermined time (“NO” in S16), the detection unit 15 notifies the order determination unit 15 accordingly.

  In response to the notification from the detection determination unit 12, the order determination unit 15 reads the first tag data 17 stored in the information storage unit 14, that is, the information of the RFID tag 1 a, and the management server via the output unit 16 20 (S21).

  On the other hand, if “YES” in the step S16, the detection determining unit 12 determines whether or not the detected distance r to the RFID tag 1 is within the detection specified range (S17). The RFID tag 1 detected here is referred to as an RFID tag 1b for convenience of explanation. The distance r between the RFID tag 1b and the antenna 30b is referred to as a distance r1b.

  When the detection determination unit 12 determines that there is no RFID tag 1b within the detection regulation range (in the case of “NO” in S17), the process proceeds to step S21 and the information of the RFID tag 1a is output to the management server 20.

  If “YES” in the step S17, the detection determination unit 12 associates the distance r1b to the RFID tag 1b with the information of the RFID tag 1b and stores the information as the second tag information 18 in the information storage unit 14. Then, the detection determination unit 12 instructs the order determination unit 15 to determine the conveyance order of the detected RFID tag 1a and RFID tag 1b.

  In response to the instruction from the detection determination unit 12, the order determination unit 15 compares the first tag information 17 and the second tag information 18, and the distance r1a of the RFID tag 1a is greater than the distance r1b of the RFID tag 1b. It is determined whether it is larger than (S19).

  Here, when it is determined that the distance r1a is larger (“YES” in S19), the order determination unit 15 first outputs the information of the RFID tag 1b to the management server 20 via the output unit 16. (S20). Next, the order determination unit 15 outputs information of the RFID tag 1a to the management server 20 via the output unit 16 (S21). And the antenna which can be communicated again is switched to the antenna 30a, and the process from step S11 is repeated.

  Conversely, if it is determined that the distance r1a is smaller (“NO” in S19), the order determination unit 15 first outputs information about the RFID tag 1a to the management server 20 via the output unit 16. (S22). Then, the order determination unit 15 outputs the information of the RFID tag 1b to the management server 20 via the output unit 16 (S23).

  In other words, in the present embodiment, the order of passage of the gate 80 of the RFID tag 1 provided in the luggage moving in a certain direction by the transport belt is specified. Since the RFID tag 1 moves in a certain direction and passes through the gate 80 in this way, the relative relationship between the RFID tags 1 in the communicable range of the antenna 30 depends on the distance between the RFID tag 1 and the antenna 30. The positional relationship can be determined.

  Further, since the antenna 30 is provided in the gate 80, it can be said that the RFID tag 1 is closer to the gate 80 as the distance r between the antenna 30 and the gate 80 becomes smaller.

  Therefore, the management apparatus 10 according to the present embodiment can specify that the RFID tag 1 passes through the gate 80 in the order of decreasing the distance r.

  As described above, when the order of the RFID tags 1 provided in the package to be transported is specified, the process returns to step S11 again and the antenna that can communicate with the RFID tag 1 is switched from the antenna 30b to the antenna 30a. repeat.

  On the other hand, if “NO” in step S12 or step S13, the process proceeds to the process “2” shown in FIG. 9, and the antenna 30 capable of communicating with the RFID tag 1 is switched from the antenna 30a to the antenna 30b (S31). Then, the presence or absence of detection of the RFID tag 1 is determined within a predetermined time by the switched antenna 30b (S32). If it is determined that the RFID tag 1 has not been detected within the predetermined time (“NO” in S32), the antenna that can communicate with the RFID tag 1 is switched to the antenna 30a again (proceed to process “1”). (See FIG. 8).

  When the time for one sequence is set as the predetermined time, the tag response signal cannot be received from the RFID tag 1 in response to the R / W request signal from the reader / writer 2. The antenna 30 is immediately switched.

  When it is determined that the RFID tag 1 has been detected within a predetermined time (“YES” in S32), it is determined whether or not the distance from the antenna 30b to the RFID tag 1 detected is within the detection specified range. (S33). The RFID tag 1 detected here is the RFID tag 1b, and the distance from the antenna 30b to the RFID tag 1b is the distance rb1.

  In step S33, when the detected distance rb1 to the RFID tag 1b is not within the detection regulation range (“NO” in S33), the process proceeds to “1” and the antenna that can communicate with the RFID tag is switched to the antenna 30a. (See FIG. 8).

  On the other hand, when the detected distance r1b to the RFID tag 1b is within the detection regulation range (“YES” in step S33), the detection determination unit 12 associates information on the RFID tag 1b and the distance r1b with the second information. The tag information 18 is stored in the information storage unit 14 (S34). As described above, when the information storage unit 18 stores the information of the RFID tag 1b and the distance rb1 to the RFID tag 1b in association with each other, the detection determination unit 12 switches the antenna to the switching instruction unit 13. To be notified. In response to the notification from the detection determination unit 12, the switching instruction unit 13 selects the antenna 30a as an antenna capable of communicating with the RFID tag 1 via the external communication unit 11, and selects the antenna 30b from the antenna 30b. It is instructed to switch to the antenna 30a.

  In response to an instruction from the switching instruction unit 13 of the management apparatus 10, in the reader / writer 2, the communication processing unit 5 controls to switch the antenna that can communicate with the RFID tag 1 to the antenna 30 a. In this way, the antenna that can communicate with the RFID tag 1 is switched to the antenna 30a (S35).

  When the antenna capable of communicating with the RFID tag 1 is switched to the antenna 30a, the detection determination unit 12 determines whether or not another RFID tag 1 has been detected within a predetermined time (S36). That is, the detection determination unit 12 determines whether or not another RFID tag (referred to as RFID tag 1a) different from the RFID tag 1b detected in step S32 is detected.

  Here, when the other RFID tag 1a is not detected within the predetermined time (“NO” in S36), the detection determination unit 12 notifies the order determination unit 15 to that effect. Then, the order determination unit 15 reads the second tag information 18 from the information storage unit 14 in response to the notification from the detection determination unit 12, and sends the information of the RFID tag 1 a to the management server 20 via the output unit 16. Output (S43).

  On the other hand, if “YES” in the step S36, the detection determining unit 12 determines whether or not the detected distance ra1 to the RFID tag 1a is within a specified range (S37). In this determination, when it is determined that the distance ra1 is not within the specified range (“NO” in S37), the detection determination unit 12 reads the second tag information 18 to the order determination unit 15 and manages the information of the RFID tag 1b. The server 20 is instructed to transmit.

  The order determination unit 15 reads the second tag information 18 from the information storage unit 14 according to the instruction from the detection determination unit 12 and outputs the information of the RFID tag 1b to the management server 20 via the output unit 16 ( S43).

  On the other hand, if “YES” in step S37, the detection determination unit 12 stores the detected RFID tag 1a and the distance r1a to the RFID tag 1a in the information storage unit 14 as the first tag information 17. (S38).

  When the detection determination unit 12 stores the first tag information 17 and the second tag information 18 in the information storage unit 14 as described above, the distance ra1 to the RFID tag 1a and the RFID tag 1b are stored in the order determination unit 15. Is instructed to be compared with the distance rb1. In response to the instruction from the detection determination unit 12, the order determination unit 15 determines whether the distance r1a is greater than r1b (S39).

  Here, when the order determination unit 15 determines that the distance r1a is greater than r1b (“YES” in S39), the order determination unit 15 reads the second tag information and sets the RFID tag 1b to the management server 20. (S40).

  Then, the order determination unit 15 reads the first tag information 17 and outputs the information of the RFID tag 1a to the management server 20 via the output unit 16 (S41). Then, the process returns to step S31, the antenna that can communicate from the antenna 30a to the antenna 30b is switched, and the above-described processing is repeated (return to "2").

  On the other hand, when the distance r1a is smaller than r1b (“NO” in S39), the order determination unit 15 reads the first tag information 17 and outputs the information of the RFID tag 1a to the management server 20 (S42). Then, the order determination unit 15 reads the second tag information 18 and outputs the information of the RFID tag 1b to the management server 20 (S43). Then, the process returns to step S31, the antenna that can communicate from the antenna 30a to the antenna 30b is switched, and the above-described processing is repeated (return to "2").

  As described above, in the management system 90 according to the present embodiment, the antenna that can communicate with the RFID tag 1 among the antennas 30 provided in the reader / writer 2 is switched until the reader / writer 2 detects the RFID tag 1. Waiting. Thus, in the management system 90 according to the present embodiment, the antenna is switched after a predetermined time has elapsed. Or the structure which switches an antenna for every completion | finish of the said sequence for predetermined times may be sufficient.

  For this reason, in the management system 90 according to the present embodiment, even when the RFID tag 1 is pasted at a position where it cannot communicate with one antenna side, the RFID tag 1 Can be detected by the other antenna, it is possible to prevent the RFID tag 1 from being missed.

  The management system 90 is configured such that only one of the antennas 30 a and 30 b can always communicate with the RFID tag 1. For this reason, detection of the RFID tag 1 can be confirmed for each antenna 30, and information on the distance r from the antenna 30 to the RFID tag 1 can be acquired.

  In addition, since the detection timing of the RFID tag 1 is divided for each antenna 30, it is possible to prevent radio waves transmitted from the antenna 30 from interfering with each other.

  In addition, when changing the frequency of the radio wave transmitted from each RFID tag 1, it is not necessary to shift the detection timing of each RFID tag 1, and it may be comprised so that it can detect simultaneously.

  Further, in the above-described “transport order specifying process” of the RFID tag 1, as shown in FIG. 7A, two packages having the RFID tag 1 are included in the range of the maximum communicable distance between the antenna 30a and the antenna 30b. Explained the case of coming. However, the above-mentioned “conveyance order specifying process” is also performed when three packages having the RFID tag 1 enter the range of the maximum communicable distance of the antenna 30a and the antenna 30b as shown in FIG. Applicable.

  That is, similar to the above-mentioned “conveyance order specifying process”, the RFID tag 1 that is detected by the antenna 30a or the antenna 30b within a predetermined time and the distance from the antenna 30a or the antenna 30b to the RFID tag 1 is within the detection specified range. Are stored in the information storage unit 14 in association with the distance information.

  For example, as shown in FIG. 7B, when the RFID tags 1α, 1β, and 1γ exist within the maximum communicable distance, the distance of the RFID tag 1α, the distance of the RFID tag 1β, and the distance of the RFID tag 1γ Are stored in the information storage unit 17, respectively. And the order determination part 15 can compare these distances, and can specify it as a conveyance order of a load in order with a short distance.

  In the management system 90 according to the present embodiment, the number of antennas 30 that detect the RFID tag 1 is two, that is, the antenna 30a and the antenna 30b, but is not limited thereto. For example, the antenna 30 may be further provided not only at both ends in the width direction of the transport belt but also in a direction facing the transport surface on which the transport belt is installed. As described above, when the antenna 30 is further provided, the RFID tag 1 can be read even when the RFID tag 1 is provided on the upper surface of the package to be transported.

  That is, it is preferable that the number of antennas 30 provided in the reader / writer 2 in the management system 90 is appropriately determined so that the RFID tag 1 provided in the package to be transported can be reliably read.

  Further, when two or more antennas 30 are provided as described above, the above-described “conveyance order specifying process” can be applied as follows.

  That is, in the above-mentioned “conveyance order specifying process”, when the RFID tag 1 is not detected within a predetermined time, or when the RFID tag 1 outside the detection regulation range is detected, between the antenna 30a and the antenna 30b, The antenna 30 that can communicate with the RFID tag 1 can be switched.

  In the above-mentioned “conveyance order specifying process”, information on the RFID tag 1 and information on the distance r to the RFID tag 1 in which the distance r between the antenna 30 and the RFID tag 1 is within the detection regulation range are obtained. After storing in the information storage unit 14, the antenna 30 is switched.

  Here, when two or more antennas 30 are provided (for example, when antennas 30a, 30b, and 30c are provided), switching of the antennas 30 under the above-described conditions is performed as follows.

  For example, when the antenna 30a can communicate with the RFID tag 1, the antenna 30a is switched to the antenna 30b. When the antenna 30b can communicate with the RFID tag 1, the antenna 30b is switched to the antenna 30c. When the antenna 30c can communicate with the RFID tag 1, the antenna 30c is switched to the antenna 30a. Then, based on the information on the distance r obtained by switching in this way, the management apparatus 10 outputs the information to the management server 20 in ascending order of the distance r.

  Further, the above-described “transport order specifying process” of the RFID tag 1 has been described on the premise of the following configuration as shown in FIG. That is, the RFID tag provided on the side of the luggage on the gate leg 81a side can communicate only with the antenna 30a, and conversely, the RFID tag 1 provided on the side of the luggage on the gate leg 81b side is communicated with the antenna 30b. Only communication was possible.

  For this reason, both the antenna 30a and the antenna 30b receive radio waves from the same RFID tag 1, and distance information is not calculated based on the radio waves (tag response signals) received by the respective antennas 30.

  However, the management apparatus 10 according to the present embodiment can be assumed that the distance to the same RFID tag 1 is separately measured by both the antenna 30a and the antenna 30b. In such a case, the order of the RFID tags 1 that pass through the gate 80 is specified by the following determination.

  That is, as shown in FIG. 7A, when two RFID tags 1α and RFID tags 1β are transported within the communicable range of the antenna 30a and the antenna 30b, the RFID tags are respectively transmitted by both the antenna 30a and the antenna 30b. Assume that the distance between 1α and the RFID tag 1β is measured.

  In this case, as the first tag information 17, the distance to the RFID tag 1α and the distance to the RFID tag 1β measured by the antenna 30a are stored. As the second tag information, the distances to the RFID tag 1α and the RFID tag 1β measured by the antenna 30b are stored.

  In such a case, first, the distance information between the RFID tag α stored as the first tag information and the RFID tag α stored as the second tag information is compared, and the smaller distance r is validated (here The effective distance information is referred to as distance r1α).

  Similarly, the distance information between the RFID tag β stored as the first tag information and the RFID tag β stored as the second tag information is compared, and the one with the smaller distance r is validated (valid here) The distance r is referred to as distance r1β). Then, the pass order of the RFID tags passing through the gate can be specified by comparing the effective distance r1α and the distance r1β.

  Moreover, although the information of the RFID tag 1 from the management apparatus 10 according to the present embodiment is configured to be output to the management server 20, the output destination is not limited to this.

  For example, a display device may be provided instead of the management server 20, and information indicating the transporting place of the RFID tag 1 may be output to the display device. In this case, the output unit 16 converts the information received from the order determination unit 15 into the displayable data format and controls the information to be displayed on the display device.

  Further, in the management system 90 according to the present embodiment, the management apparatus 10 uses the distance r between the RFID tag 1 and the antenna 30 of the reader / writer 2 to allow a package with the RFID tag 1 to pass through the gate 80. It was the composition which specified order. However, the present invention is not limited to this. For example, the gate leg 81a and the gate leg 81b are each provided with two or three antennas, and the two-dimensional coordinates or the three-dimensional coordinates of the RFID tag 1 are calculated. The structure which specifies the conveyance order of RFID tag 1 based on the positional information shown by a three-dimensional coordinate may be sufficient.

  In the present embodiment, the object on which the RFID tag 1 is provided is a luggage, but is not limited to this. For example, the RFID tag 1 may be a part such as a part in a production line or a person who passes a predetermined position. Or an animal.

  Note that the communication processing unit 5, the position measurement unit 6, and the external communication unit 7 included in the reader / writer 2, the external communication unit 11, the detection determination unit 12, the switching instruction unit 13, and the order determination unit 15 included in the management device 10. The output unit 16 may be configured by hardware logic, and is realized by a calculation unit such as a CPU executing a program stored in a storage unit such as a ROM (Read Only Memory) or a RAM. It may be configured to.

  When each of the above-described configurations is configured by calculation means such as a CPU and storage means, the reader / writer 2 is provided by a computer having these means reading a recording medium on which the program is recorded and executing the program. The communication processing unit 5, the position measurement unit 6, and the external communication unit 7, and the external communication unit 11, the detection determination unit 12, the switching instruction unit 13, the order determination unit 15, and the output unit 16 included in the management device 10 are realized. can do. In addition, by recording the program on a removable recording medium, the various functions and various processes described above can be realized on an arbitrary computer.

  As this recording medium, a program medium such as a memory (not shown) such as ROM may be used for processing by a computer, and a program reader is provided as an external storage device (not shown). The program medium may be readable by inserting a recording medium therein.

  In any case, the stored program is preferably configured to be accessed and executed by the microprocessor. Furthermore, it is preferable that the program is read out, and the read program is downloaded to a program storage area of the microcomputer and the program is executed. It is assumed that this download program is stored in advance in the main unit.

  In addition, if the system configuration is capable of connecting to a communication network including the Internet, the recording medium is preferably a recording medium that fluidly carries the program so as to download the program from the communication network.

  Further, when the program is downloaded from the communication network as described above, it is preferable that the download program is stored in the main device in advance or installed from another recording medium.

  In the management system 90 according to the present embodiment, the reader / writer 2 and the management apparatus 10 are configured separately. However, the present invention is not limited to this, and the reader / writer 2 and the management apparatus 10 are configured integrally. May be.

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope shown in the claims. That is, embodiments obtained by combining technical means appropriately changed within the scope of the claims are also included in the technical scope of the present invention.

  In the storage / retrieval management system according to the present invention, the order of passage of RFID tags at a predetermined position can be specified, so that an object equipped with an RFID tag moves as in this embodiment, for example, logistics, retail It can be applied in a wide range of fields such as production lines.

1, showing an embodiment of the present invention, is a block diagram showing a main configuration of a management system. FIG. It is a figure which shows an example of the management system which concerns on this Embodiment. 1, showing an embodiment of the present invention, is a block diagram showing a schematic configuration of a management system. FIG. FIG. 2 is a block diagram showing an outline of a configuration for measuring a distance between an RFID tag and the reader / writer in the reader / writer included in the management system according to the present embodiment. FIG. 6A is a diagram showing a state in which an R / W request signal and a tag response signal are transmitted and received between the reader / writer and the RFID tag, and FIG. It is a figure which shows a transmission state, The figure (c) is a figure which shows the transmission state of a tag response signal. It is a figure which shows the variation | change_quantity of the phase at the time of transmission / reception of the R / W request signal and tag response signal by two different frequencies. It is a figure which shows the reading state by the antenna of the RFID tag in the management system which concerns on this embodiment, The figure (a) shows the case where two RFID tags exist in the communicable range of an antenna, b) is a diagram showing a case where there are three RFID tags within the communicable range of the antenna. It is a flowchart which shows the flow of a conveyance order specific process. It is a flowchart which shows the flow of a conveyance order specific process. It is a figure which shows an example of the range which can communicate by the antenna of the reader / writer with which the management system which concerns on this embodiment is provided.

Explanation of symbols

1 RFID tag 2 Reader / writer (tag communication device)
6 Position measurement unit (position calculation means)
7 External communication unit (transmission means)
10 Management device (information processing device)
11 External communication unit (accepting means)
12 Detection determination part (determination means)
13 switching instruction part (switching instruction means)
15 Order determining unit (specifying means)
16 Output unit (output means)
17 First tag information (distance information)
18 Second tag information (distance information)
30a antenna 30b antenna 80 gate (predetermined position)
90 Management system

Claims (13)

A management system comprising an information processing device and a tag communication device,
The tag communication device includes a plurality of antennas arranged at different positions for receiving radio waves from RFID tags attached to an object passing through a predetermined position in a row, and the plurality of antennas Switching means for switching between, a position calculating means for calculating the distance between the antenna and the RFID tag based on the radio wave from the RFID tag received by each antenna, and the distance information calculated by the position calculating means for the information processing have a transmission means for transmitting device,
The information processing apparatus associates each distance information, which is the distance information calculated based on the radio wave from the RFID tag, with the information of the RFID tag, and receives the tag information from the tag communication apparatus. A specific means for comparing all of the distance information and specifying the passing order of the RFID tags at a predetermined position;
Furthermore, the information processing apparatus has detection determination means for determining whether or not an RFID tag different from the RFID tag received before the reception means switches the antenna is detected after switching the antenna, The accepting means accepts the distance information calculated based on the radio wave from the different RFID tag and the information of the different RFID tag in association with each other when the detection determining means detects the different RFID tag. Management system featuring.   The tag communication device further includes signal transmission means for transmitting a transmission signal for the position calculation means to calculate the distance,
  The position calculating means includes a change amount of the phase of the response signal with respect to the transmission signal of the first frequency transmitted by the signal transmission means, and a phase of the response signal with respect to the transmission signal of the second frequency transmitted by the signal transmission means. The management system according to claim 1, wherein the distance is calculated based on a difference from a change amount.   The position calculating means sets the distance to be calculated as r and the first frequency as f. ₁ , The second frequency is f ₂ , The amount of change in the phase of the response signal with respect to the transmission signal of the first frequency is φ ₁ , The amount of change in the phase of the response signal with respect to the transmission signal of the second frequency is φ ₂ If the speed of light is c,
  r = c (φ ₁ −φ ₂ ) / (4π | f ₁ -F ₂ ｜)
The management system according to claim 2, wherein the distance r is calculated based on The information processing apparatus includes a determination unit that determines whether each of the distance information received by the receiving unit is within a specified range in which the tag communication device can directly communicate with the RFID tag,
The specific means, according to claim 1, wherein the exclusion distance information is determined not within the specified range by the determining means, from the comparison in order to identify the order of passage of the RFID tag at a given position The management system according to any one of the above. The information processing apparatus includes an instruction unit that selects a part of the plurality of antennas and instructs the tag communication apparatus to enable transmission / reception of radio waves with the RFID tag at the selected antenna. The management system of any one of Claims 1-4 characterized by the above-mentioned. When the receiving unit has not received the distance information from the tag communication device for a predetermined period or when receiving the distance information of all RFID tags that can receive radio waves, the information processing device 6. The management system according to claim 5 , wherein the switching unit instructs the switching unit to switch antennas. The said information processing apparatus is provided with the output means which outputs the information which shows the passage order of the RFID tag in the predetermined position specified by the said specific means , The one of Claims 1-6 characterized by the above-mentioned. Management system . A control method of a management system comprising an information processing device and a tag communication device,
The tag communication device switches a plurality of antennas arranged at different positions for transmitting / receiving radio waves to / from an RFID tag attached to an object passing through a predetermined position in a line, A position calculating step for calculating the distance between the antenna and the RFID tag based on the received radio wave from the RFID tag ;
A transmission step in which the tag communication device transmits the distance information calculated in the position calculation step to the information processing device;
The information processing device accepting each distance information, which is information on the distance calculated based on radio waves from the RFID tag, from the tag communication device in association with the information of the RFID tag;
The information processing device compares all the received distance information and specifies the passing order of RFID tags at a predetermined position ;
Determining whether the information processing apparatus has detected an RFID tag different from the RFID tag received before switching the antenna in the receiving step after switching the antenna;
When the information processing apparatus detects the different RFID tag in the determining step, the information processing apparatus includes a step of receiving the distance information calculated based on radio waves from the different RFID tag and the information of the different RFID tag. A control method for a management system .   The tag communication device further includes a signal transmission step of transmitting a transmission signal for calculating the distance,
  In the position calculation step, the amount of change in the phase of the response signal with respect to the transmission signal of the first frequency transmitted in the signal transmission step and the response signal with respect to the transmission signal of the second frequency transmitted in the signal transmission step The management system control method according to claim 8, wherein the distance is calculated based on a difference from a phase change amount.   In the position calculating step, the distance to be calculated is r, and the first frequency is f. ₁ , The second frequency is f ₂ , The amount of change in the phase of the response signal with respect to the transmission signal of the first frequency is φ ₁ , The amount of change in the phase of the response signal with respect to the transmission signal of the second frequency is φ ₂ If the speed of light is c,
  r = c (φ ₁ −φ ₂ ) / (4π | f ₁ -F ₂ ｜)
10. The method of controlling a management system according to claim 9, wherein the distance r is calculated based on. A plurality of antennas arranged at different positions for transmitting / receiving radio waves to / from an RFID tag attached to an object passing through a predetermined position in a line, and switching the plurality of antennas. An information processing device that receives and processes information from a tag communication device that calculates a distance between an antenna and an RFID tag based on radio waves from an RFID tag received by
Each of the distance information, which is information of the distance calculated based on the radio wave from the RFID tag, is associated with the information of the RFID tag and is received from the tag communication device;
A comparison unit that compares all of the received distance information and specifies the passing order of RFID tags at a predetermined position; and
The information processing apparatus further includes a determination unit that determines, after switching the antenna, whether or not an RFID tag different from the RFID tag received by the receiving unit before switching the antenna is detected. When the determination unit detects the different RFID tag, the means receives the distance information calculated based on the radio wave from the different RFID tag and the information of the different RFID tag. . A control program for operating the control system according to claim 1, the management system control program for causing a computer to function as each means. The computer-readable recording medium which recorded the control program of the management system of Claim 12 .

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