JP2010032442A - Positioning system and processing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To measure the position of a moving object which does not have a sensor, a radio tag, a communication terminal device, or the like, mounted thereon, in a space in which an open environment of radio waves cannot be obtained. <P>SOLUTION: This processing device correlates the first analysis result of a received waveform by the first moving object on which a terminal device is mounted with the position of the terminal device, and records the result in a database device; and when acquiring a received waveform by the second moving object on which a terminal device or the like is not mounted, compares the second analysis result of the received waveform with the first analysis result recorded in the database device, and outputs the position of the terminal device, when acquiring a pertinent result as the position of the second moving object. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a positioning system, and more particularly to a wireless signal indicating the position of a moving object (for example, a human being or an autonomous traveling device) to which a sensor, a communication terminal device or the like is not attached in a space where a radio wave visibility environment cannot be obtained. The present invention relates to a system and an apparatus for measuring a change in received waveform.

  In tracing of goods, security, etc., a method for detecting the presence of a moving object and a method for measuring a position are required. To date, two methods are known in general.

  In the first method, in order to measure the position of a moving object in which it is difficult to attach a sensor, a wireless tag, a communication terminal device, etc., a transmitter / receiver directs radio waves, ultrasonic waves, etc. to the moving object, This is a method of measuring the distance between a moving object and a transmitter / receiver by measuring a round trip time until a reflected wave is received (see, for example, Patent Document 1).

The second method is a space where a line-of-sight environment cannot be obtained, and a radio signal is transmitted from a transmitter and received as a moving object detection method when radio waves, ultrasonic waves or the like cannot be directed to the moving object. This is a method of detecting a moving object from a change in a delay profile of a radio signal received by a machine (see, for example, Patent Document 2 and Patent Document 3). The delay profile is a distribution that shows the temporal profile of the received signal strength, including not only the signal that directly reaches the receiver from the transmitter, but also the signal that arrives at the receiver after being reflected by an obstacle. If there is a moving object even outside the environment, this intensity distribution changes. Therefore, by detecting a change in the delay profile, it is possible to detect a moving object that exists in a space where a line-of-sight environment cannot be obtained.
JP-A-10-39015 JP-A-5-166074 JP 2003-185735 A

  If it is difficult to obtain a line-of-sight environment between the radio and the moving object due to obstacles, such as indoors, the first method cannot accurately measure the propagation time of the radio wave between the radio and the moving object. It is difficult to measure the position of a moving object.

  In the second method, the presence of a moving object can be detected by comparing changes in delay profiles, but the position of the moving object cannot be measured.

  The present invention is an indoor environment where it is difficult to obtain a view of a wireless device and a moving object due to an obstacle, without attaching this to a moving object in which it is difficult to attach a sensor, a wireless tag, a communication terminal device, etc. A positioning system for measuring the position of the moving object is provided.

  A typical example of the present invention is as follows. That is, the first invention is a positioning system that measures the position of a moving object using the analysis result of the waveform of the received signal, and a terminal that measures the position of a terminal device attached to the first moving object. Reflected by a position measuring device, a first wireless device comprising at least a transmitter, a second wireless device comprising at least a receiver, a direct wave transmitted by the first wireless device, and a first moving object Analyzing the waveform of the signal by the reflected wave and generating a first analysis result, and a database for recording the first analysis result generated by the processing device and the position of the first moving object And the processing device records the location of the terminal device measured by the terminal location measuring device and the first analysis result in association with each other, and the first wireless device When acquiring the signal waveform of the transmitted direct wave and the reflected wave reflected by the second moving object, the second analysis result generated from the acquired waveform and the first recorded in the database When the second analysis result is determined to correspond to the first analysis result, the position of the terminal device corresponding to the corresponding first analysis result is compared with the second analysis result. The position of the moving object is determined.

  According to an embodiment of the present invention, it is possible to measure the position of a moving object without attaching the sensor, the wireless tag, the communication terminal device, or the like to a moving object that is difficult to attach.

<Embodiment 1>
A first embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 is a configuration diagram of a positioning system according to a first embodiment of this invention.

  The positioning system includes a terminal device 2, a plurality of wireless devices 1, a processing device 6, and a database device 7, and each device is connected by a network 5 using a wireless line or a wired line.

  The wireless device 1 has a function of transmitting a wireless signal and a function of receiving a wireless signal propagated through the space 8, and a function of transmitting the received waveform of the wireless signal to the processing device 6 connected by the network 5. A UWB impulse radio signal 4 is used as a radio signal to be transmitted to the space 8. Here, UWB (Ultra Wide Band) is one of wireless transmission systems using a very wide frequency band, and a pulse signal of several nanoseconds or less is used.

  In addition, a plurality of wireless devices 1 are installed in a space 8 where a line-of-sight environment is not obtained, for example, an indoor space, and measure a received waveform pattern that changes depending on the radio wave propagation environment of the space 8 at a plurality of fixed points.

  The first radio device 1 transmits a UWB impulse radio signal 4 toward the space 8, and at least one second radio device 1 other than the first radio device 1 transmits the UWB impulse propagated through the space 8. A radio signal 4 is received. At this time, the first wireless device 1 that has transmitted the UWB impulse wireless signal 4 creates a trigger for notifying the transmission in the signal generation control unit 12 and notifies the second wireless device 1 via the network 5. May be.

  Note that only the predetermined first wireless device 1 does not continuously transmit the UWB impulse wireless signal 4, but the first wireless device 1 and the receiver that become transmitters at predetermined time intervals. By sequentially switching the two radio devices 1, it is possible to obtain received waveform patterns from more fixed points without changing the arrangement of the radio devices 1.

  In this case, in order to specify which radio device 1 is the transmission source of the UWB impulse radio signal 4, it is necessary to include the unique ID assigned to each radio device 1 in the UWB impulse radio signal 4 for transmission. There is. As a method for adding the unique ID to the transmission signal, a method using a positive / negative pattern of the impulse train of the UWB impulse radio signal 4 can be considered.

  The terminal device 2 is attached to the first moving object 3 (for example, a human being, an animal, an autonomous mobile device, etc.), and transmits its position to the processing device 6 connected by the network 5 and the function of measuring its own position. It has a function to do.

  When the first moving object 3 to which the terminal device 2 is attached moves in the space 8, the terminal device 2 sequentially measures its own position and transmits the measured position to the processing device 6 as the position of the moving object 3. To do.

  The UWB impulse radio signal 4 propagates in the space 8 and is received by at least one radio device 1. The UWB impulse radio signal 4 may be transmitted from a predetermined one radio device 1 or a plurality of radio devices 1 sequentially switch the roles of transmission and reception, and the radio device which has become the role of transmission 1 may be transmitted. At this time, the UWB impulse radio signal 4 is preferably a signal including an ID unique to the radio device 1. For example, a technique of notifying an ID with a positive / negative pattern of an impulse train of the UWB impulse radio signal 4 can be adopted.

  The processing device 6 is connected to the wireless device 1, the terminal device 2, and the database device 7 through the network 5. The processing device 6 is configured such that the timing at which the terminal device 2 performs its own position measurement through the network 5, the coordinates of the terminal device 2 obtained by this position measurement, and the first (transmitting) radio device 1 transmits the UWB impulse radio signal 4, the timing at which at least one second (receiving side) radio device 1 receives the UWB impulse radio signal 4 transmitted by the first (transmitting side) radio device 1, and A reception waveform of the UWB impulse radio signal 4 propagated in the space 8 is obtained. Then, the processing device 6 performs processing for associating the position information transmitted from the terminal device 2 with the pattern of the received waveform transmitted from the first wireless device 1. Further, the processing device 6 stores information in which the position information and the received waveform pattern are associated with each other in the database device 7.

  In addition, the processing device 6 has a UWB in a space 8 where the first (transmitting side) wireless device 1 has a second moving object to which a terminal device or the like (sensor, wireless tag, communication terminal device, or the like) is not attached. When the impulse radio signal 4 is transmitted and at least one second (receiving side) radio device 1 other than the first radio device 1 acquires a reception waveform of the signal reflected by the second moving object The received waveform is analyzed, the analyzed received waveform pattern is compared with the received waveform pattern stored in the database device 7, and if the respective patterns match each other, the pattern corresponds. The attached position of the terminal device 2 is output as the position of the second moving object.

  Thereby, even when the second moving object to which the terminal device or the like is not attached moves in the space 8, the received waveform pattern based on the first moving object 3 stored in the database device 7 is referred to. Thus, the position can be detected.

  The database device 7 has a function of holding correspondence data between the position measurement result of the terminal device 2 and the received waveform pattern, and is connected to the wireless device 1, the terminal device 2, and the processing device 6 through the network 5.

  The data held by the database device 7 records the correspondence between the position measurement result of the terminal device 2 and the pattern of the received waveform, and the database is constructed by a general relational database management system such as PostgreSQL, MySQL, etc. Is done. Further, the database device 7 may use, as data, a model that stochastically stores the correspondence between the position measurement result of the terminal device 2 and the pattern of the received waveform, and the received waveform pattern of the UWB impulse radio signal 4 is used as an input value. A self-learning neural network that uses the position measurement result of the terminal device 2 as an output value may be used as data. It is preferable to use the position measurement result of the terminal device 2 as the teacher signal in the learning process of the neural network.

  The network 5 can be constructed by a wired line, a wireless line, or both a wired line and a wireless line, and the wireless device 1, the terminal device 2, and the processing device 6 are connected. If a wired line is used, Ethernet (registered trademark) may be used, and if a wireless line is used, a so-called wireless LAN represented by the IEEE 802.11b standard may be used.

  Further, the network 5 may be constructed by the terminal device 2, the processing device 6, and the database device 7 having a function capable of transmitting and receiving the UWB impulse radio signal 4.

  Next, the configuration of the wireless device 1 will be described.

  FIG. 2 is a block diagram illustrating a configuration of the wireless device 1 according to the first embodiment of this invention.

  The wireless device 1 includes an antenna 11, a signal generation control unit 12, a UWB impulse radio signal transmission unit 13, a communication unit 14, and a UWB impulse radio signal reception unit 15.

  The antenna 11 is an antenna that transmits and receives the UWB impulse radio signal 4 and is connected to the UWB impulse radio signal transmission unit 13 and the UWB impulse radio signal reception unit 15. The antenna 11 may be an array antenna, and may be configured such that a plurality of reception signals can be received by the UWB impulse radio signal reception unit 15 of one radio device 1.

  The signal generation control unit 12 is a control unit that determines the timing for transmitting the UWB impulse radio signal 4, and is connected to the UWB impulse radio signal transmission unit 13, the UWB impulse radio signal reception unit 15, and the communication unit 14. The time when the UWB impulse radio signal transmission unit 13 is activated is determined based on the timing at which the terminal device 2 measures its position transmitted through the network 5 or the instruction of the processing device 6. Note that the activation time may be determined based on a signal of a timer built in the wireless device 1.

  In addition, the signal generation control unit 12 converts the ID unique to the wireless device 1 and information related to the wireless device 1 into a bit string, and includes an instruction to transmit the converted bit string in the UWB impulse wireless signal 4 to transmit the UWB impulse wireless signal. You may provide the function given to the transmission part 13. FIG.

  The UWB impulse radio signal transmission unit 13 is a processing unit that generates and transmits the UWB impulse radio signal 4, and is connected to the antenna 11 and the signal generation control unit 12. The UWB impulse radio signal transmission unit 13 receives a command from the signal generation control unit 12 and transmits the UWB impulse radio signal 4 from the antenna 11. The UWB impulse radio signal transmission unit 13 may have a function of superimposing a spreading code such as an M sequence to reduce communication errors.

  The communication unit 14 is an interface that connects each functional module in the wireless device 1 and the network 5, and a process in which the reception waveform of the UWB impulse radio signal 4 received by the UWB impulse radio signal reception unit 15 is connected to the network 5. Transmit to device 6.

  The UWB impulse radio signal receiving unit 15 has a function of receiving the UWB impulse radio signal 4 transmitted from the first radio device 1 and a function of measuring a received waveform of the received UWB impulse radio signal 4. The received waveform is transmitted to the processing device 6 through the communication unit 14 and the network 5. Further, when the UWB impulse radio signal transmission unit 13 performs code spreading by superimposing spreading codes such as M-sequences, the UWB impulse radio signal receiving unit 15 receives by spreading and spreading the same spreading codes. Demodulate the signal.

  The wireless device 1 may be configured to have a signal processing function and transmit only the result of analyzing the received waveform of the UWB impulse wireless signal 4 to the processing device 6. In this case, a general-purpose processor or a dedicated LSI for analyzing the received waveform is incorporated in the wireless device 1.

  The analysis of the received waveform will be described later.

  Next, the configuration of the processing device 6 will be described.

  FIG. 3 is a block diagram illustrating a configuration of the processing device 6 according to the first embodiment of this invention.

  The processing device 6 includes a communication unit 21, a signal preprocessing unit 22, a feature amount generation unit 23, and a feature amount comparison unit 24, and is connected to the wireless device 1, the terminal device 2, and the database device 7 through the network 5.

  The communication unit 21 is a communication interface that connects each functional module (the signal preprocessing unit 22, the feature amount generation unit 23, and the feature amount comparison unit 24) in the processing device 6 and the network 5. The communication unit 21 receives the reception waveform of the UWB impulse radio signal 4 received by at least one second radio device 1 through the network 5 and outputs the received reception waveform to the signal preprocessing unit 22. In addition, the communication unit 21 receives the position information of the terminal device 2 transmitted from the terminal device 2 through the network 5 and outputs the received position information to the signal preprocessing unit 22.

  The signal preprocessing unit 22 performs signal preprocessing on the input reception waveform and outputs a reception waveform shaped into a waveform suitable for signal analysis to the feature amount generation unit 23.

  The signal preprocessing in the signal preprocessing unit 22 includes processing for calculating a moving average in the time domain, processing by a low-pass filter (for example, a Chebyshev low-pass filter), processing for calculating an ensemble average of a plurality of received waveforms, and the like. There is. These processes are all for reducing noise. It is also possible to perform upsampling and interpolation of the signal to shape the received waveform into a waveform suitable for signal analysis. In general, the amount of calculation of signal preprocessing is enormous, so that signal preprocessing may be performed by a general-purpose processor, but it is preferable that the signal preprocessing is performed on a dedicated LSI. .

  In the present embodiment, it is preferable to use ensemble average calculation for signal preprocessing. Here, the ensemble average is a method of calculating the average of a plurality of signal waveforms.

  FIG. 4 is a conceptual diagram of ensemble average calculation of a received waveform according to the first embodiment of this invention.

  When the position measurement result of the terminal device 2 has the same value or falls within a predetermined range, that is, the signal pre-processing unit 22 has the first moving object 3 to which the terminal device 2 is attached at the same position. For received waveforms when it is determined that they are present, an ensemble average of those received waveforms is calculated, and the calculated ensemble average is input to the feature value generation unit 23. Since the noise component is removed by calculating the ensemble average and only the waveform suitable for signal analysis can be extracted, it is preferable to perform the ensemble average processing in the signal preprocessing unit 22.

  When the wireless device 1 and the processing device 6 are connected by the network 5 as in the present embodiment, the time when the first wireless device 1 transmits the UWB impulse wireless signal 4 and one second wireless device. The time at which 1 receives the UWB impulse radio signal 4 is input to the communication unit 21 of the processing device 6 through the network 5.

  The signal preprocessing unit 22 calculates the synchronization point of the signal indicated by the signal transmission time and the signal reception time, and the reception waveform 31, the reception waveform 32, and the reception waveform received by one second wireless device 1 at different timings. 33 are overlapped with reference to the synchronization point calculated for each signal, and an average of signal strength, that is, an ensemble average 34 is calculated.

  Further, even when the processing device 6 is not notified of the transmission time of the UWB impulse radio signal 4 by the first radio device 1 or the reception time of the UWB impulse radio signal 4 by the second radio device 1, the correlation of the reception waveform is maximum. Can be detected, and thereby the ensemble average 34 of the received waveform 31, received waveform 32 and received waveform 33 at the estimated synchronized point can be obtained.

  Returning to the description of the configuration of the processing device 6 shown in FIG.

  The feature value generation unit 23 analyzes the received waveform preprocessed by the signal preprocessing unit 22 and extracts a plurality of feature values. The feature quantity generation unit 23 is connected to the communication unit 21, the signal preprocessing unit 22, and the feature quantity comparison unit 24.

  The feature amount generation unit 23 associates the first feature amount (for example, feature vector) extracted from the received waveform of the first moving object 3 with the position information transmitted from the terminal device 2, and the associated information To the communication unit 21, and the communication unit 21 of the processing device 6 transmits the information to the database device 7. The database device 7 records information associating the feature amount extracted from the received waveform with the position information of the terminal device 2 in the correspondence data.

  In addition, the feature value generation unit 23 analyzes the received waveform of the second moving object to which no terminal device or the like is attached, and extracts the second feature value.

  The feature amount is a physical amount that generally represents the feature of a signal, and there are various types. For example, signal statistical values (signal average, variance, median, maximum, minimum, mode, etc.), feature quantities related to frequency components such as signal spectrum, calibration values (moving objects in space) Difference between the received waveform when not moving, the received waveform when there are a predetermined number of people in the space, and the received waveform when the moving object is moving along a predetermined trajectory at a constant speed Correlation values (or a difference value between a signal reception waveform at a certain time and a reception waveform before a certain time, an average value of reception waveforms for the past several times, etc.), a reception waveform by a radio signal, and an output value by a sensor such as a camera image microphone Difference value correlation value and the like.

  Moreover, it is not necessary to use all the extracted feature values, and some of them may be combined and used as a vector as necessary. For example, it is conceivable to use the average value and variance value of the received signal as a feature vector.

  In the present embodiment, it is particularly preferable that the feature quantity generation unit 23 calculates a delay profile of the received signal as the feature quantity.

  FIG. 5 is a diagram illustrating an example of a delay profile characteristic of a reception waveform according to the first embodiment of this invention.

  The delay profile is a characteristic amount peculiar to a radio signal, and indicates a delay time until arrival of a delay wave and its intensity distribution with respect to a signal that reaches the receiver via multipath. Since this delay profile changes depending on the state of the propagation path, it can be said that it represents the physical state of the space 8. The highest peak of the waveform shown in FIG. 5 is a direct wave reflected from the moving object and reaches the receiver, and some peaks appearing after the direct wave are reflected waves propagated through the space 8. Other small waves represent noise components.

  Note that the feature amount extraction in the feature amount generation unit 23 may be performed on the second radio device 1 side that receives the UWB impulse radio signal 4. In this case, it is preferable to incorporate a general-purpose processor or a dedicated LSI that performs feature amount calculation into the wireless device 1.

  Returning to the description of the configuration of the processing apparatus 6 shown in FIG.

  The feature amount comparison unit 24 compares the feature amounts extracted from the received waveforms. The feature amount comparison unit 24 is connected to the communication unit 21 and the feature amount generation unit 23.

  The feature quantity comparing unit 24 records the first feature quantity of the received waveform recorded by the first moving object 3 recorded in the database device 7 and the second received waveform of the second moving object to which no terminal device or the like is attached. When the two feature quantities are compared with each other and a result of matching is obtained, the position of the terminal device 2 associated with the feature quantity is output as the position of the second moving object.

  Note that the feature quantity comparison unit 24 determines the closeness or similarity of the plurality of feature quantities when comparing the feature quantities of the received waveforms. Specific criteria include Euclidean distance, Mahalanobis distance, correlation coefficient, difference value, and the like between feature quantities to be compared. These can be modified to suit the environment used.

  Further, the feature quantity comparison unit 24 is a second moving object to which a terminal device or the like is not attached due to a change in the second feature quantity of the received waveform received by at least one second wireless device 1. It has a function to detect the movement of and output it. Here, the detection of the movement of the second moving object is based on a comparison of feature amounts. For example, the feature quantity comparison unit 24 includes the second feature quantity of the received waveform received by the second radio device 1 and the second feature quantity of the received waveform received before receiving the second feature quantity. The Euclidean distance is calculated, and when the calculated Euclidean distance exceeds a predetermined threshold, it is determined that the second moving object has moved.

  Next, in the embodiment of the present invention, a method for detecting the position and movement of a moving object without attaching a sensor, a wireless tag, a communication terminal device, or the like to the moving object without imposing a burden on the moving object will be described with reference to FIG. This will be described with reference to FIG.

  FIG. 6 is a flowchart showing a process for recording the position measurement result of the terminal device 2 and the first feature quantity of the received waveform by the first moving object 3 in association with each other in the first embodiment of the present invention. is there.

  When the first moving object 3 to which the terminal device 2 is attached moves in the space 8, the radio wave propagation environment in the space 8 changes depending on the first moving object 3 itself. Accordingly, the waveform received by the first moving object 3 changes depending on the position of the first moving object 3.

  First, the terminal device 2 attached to the first moving object 3 measures its own position, and transmits the obtained position information and measured timing to the processing device 6 (step S10). The position of the terminal 11 is the position of the first moving object 3 that causes a change in the received waveform. A method for measuring the position of the terminal device 2 will be described later with reference to FIG.

  Next, the first wireless device 1 recognizes through the network 5 that the position measurement of the terminal device 2 has been performed in step S10, and then moves toward the space 8 where the first moving object 3 is present. The wireless signal 4 is transmitted and the number of transmissions is counted (step S11).

  Next, the processing device 6 determines whether or not the terminal device 2 attached to the first moving object 3 has moved (step S11A). If it is determined in step S11A that the terminal device 2 has not moved, the process proceeds to step S12. If it is determined that the terminal device 2 has moved, the number of transmissions of the UWB impulse radio signal 4 in the radio device 1 is determined. The counter is initialized and the counter is reset to 0 (step S11B). Through these processes, the processing device 6 can acquire a reception waveform corresponding to a plurality of transmission timings while the first moving object 3 that causes a change in the reception waveform is located at the same coordinates, By superimposing the acquired received waveforms, a more accurate ensemble average can be calculated.

  Note that the movement of the terminal device 2 is not the same as the result of the position measurement of the terminal device 2 notified from the terminal device 2 to the processing device 6 in step S10, or not within a predetermined range. It is detected by being judged.

  Next, at least one second wireless device 1 other than the first wireless device 1 receives the UWB impulse wireless signal 4 propagated in the space 8 by the UWB wireless signal receiving unit 15 through the antenna 11, A received waveform is measured (step S12).

  At this time, the first radio 1 that has transmitted the UWB impulse radio signal 4 and the second radio 1 that receives the UWB impulse radio signal 4 are connected to each other by the network 5, so The wireless device 1 may create a trigger for notifying that the UWB impulse wireless signal 4 has been transmitted in the signal generation control unit 12, output the trigger to the communication unit 14, and notify the second wireless device 1 through the network 5. .

  The second wireless device 1 transmits the measured received waveform to the processing device 6 through the network 5 (step S13).

  Next, the signal preprocessing unit 22 of the processing device 6 uses the timing at which the first radio 1 transmits the UWB impulse radio signal 4 and the timing at which the second radio 1 receives the UWB impulse radio signal 4. Then, signal preprocessing for noise removal is performed as preprocessing of the received waveform (step S14).

  As described above, this signal preprocessing includes processing for calculating a moving average, processing by low-pass filtering, processing for calculating an ensemble average of a plurality of received waveforms, and the like. The signal preprocessing unit 22 inputs a received waveform shaped into a waveform suitable for signal analysis to the feature value generation unit 23. In addition, this pre-processing may be performed in the second radio device 1 when the second radio device 1 receives the radio signal 14. In this case, a general-purpose processor may be incorporated in the wireless device 1 and calculation may be performed by this processor. However, a dedicated LSI including a circuit configuration specialized for the preprocessing function may be incorporated in the wireless device 1 and used. Is preferred.

  Next, the feature quantity generation unit 23 analyzes the received waveform input from the signal preprocessing unit 22 and extracts a first feature quantity from the received waveform (step S15).

  The elements of the feature amount are as described above. In addition to the delay profile, for example, a statistical value such as a signal average value, variance, median value, maximum value, minimum value, mode value, and signal frequency component such as a spectrum. Quantity, calibration value, that is, the received waveform when there is no moving object in the space, the received waveform when there is a predetermined number of people in the space, and the trajectory where the moving object is determined at a constant speed Difference value and correlation value with received waveform when moving, difference value with received waveform before a certain time, average value of received waveform for several past times, sensors other than wireless signals such as camera images and microphones There are a difference value and a correlation value between the output value and the received waveform.

  Note that the feature amount may be extracted by incorporating a general-purpose processor into the wireless device 1 and calculating with the general-purpose processor. However, when the amount of calculation of signal processing becomes enormous, the wireless device 1 extracts feature vectors. It is preferable to incorporate and use a dedicated LSI including a suitable circuit configuration.

  Next, the feature amount generation unit 23 associates the extracted first feature amount with the position information of the terminal device 2 notified in step S10, and records the associated information in the database device 7. (Step S16).

  Further, when the associated information is recorded as an entry in the database device 7 and an entry in which the position of the same terminal device 2 as that entry already exists, the existing entry is changed to the new entry. Or the average of the existing entry and the new entry may be taken as the latest entry. The new entry may be stored as an entry different from the existing entry.

  By repeating the above procedure, the corresponding data entries of the database device 7 are accumulated one after another, covering the observation area of the space 8. In addition, since the information is sequentially updated, even when the propagation environment changes, the change can be followed.

  In addition, as calibration, a feature amount (feature vector) when no moving object is present in the observation region, a feature amount (feature vector) when the moving object is moving in a predetermined direction at a constant speed, etc. May be obtained. A change in the moving direction of the moving object can be detected by acquiring the feature amount of the moving object that moves at a constant speed.

  Next, the processing device 6 (or the wireless device 1) determines whether or not the UWB impulse radio signal 4 has been transmitted for a predetermined number of pulses (step S17).

  When it is determined that the UWB impulse radio signal 4 has not been transmitted a predetermined number of times, the processes from step S10 to step S16 are repeated until the predetermined number of times is reached. As a result, a large number of received waveform patterns by the first moving object 3 can be collected, and a more accurate ensemble average can be calculated.

  On the other hand, when it is determined that the UWB impulse radio signal 4 has been transmitted a predetermined number of times, the treatment device 16 (or the radio device 1) alternates between the first radio device 1 and the second radio device 1. (Step S18). By transmitting the UWB impulse radio signal 4 from another radio 1 installed at a position different from that of the first radio 1, it is received from more fixed points without changing the arrangement of the radio 1. A waveform pattern can be obtained.

  As described above, the position information of the terminal device 2, that is, the position information of the first moving object 3 and the first feature amount of the received waveform by the first moving object 3 are obtained by the processing from step S10 to step S18 shown in FIG. Are associated, and the associated information is recorded in the correspondence data of the database device 7.

  Next, processing for measuring the position of the second moving object to which no terminal device or the like is attached will be described. When the second moving object moves in the space 8, the radio wave propagation environment in the space 8 changes depending on the second moving object itself. Therefore, the received waveform obtained by the wireless device 1 has a pattern depending on the position of the second moving object.

  FIG. 7 shows a comparison between the second feature value extracted from the received waveform of the second moving object and the first feature value recorded in the database device 7 in the first embodiment of the present invention. It is a flowchart which shows the process which outputs the position of a 2nd moving object.

  First, the first radio 1 transmits the UWB impulse radio signal 4 toward the space 8 in which the second moving object to which no terminal device or the like is attached is present (step S20). At least one second wireless device 1 other than the first wireless device 1 receives the UWB impulse wireless signal 4 propagated in the space 8 by the UWB impulse wireless signal receiving unit 15 through the antenna 11, The received waveform by the moving object is measured (step S21). Next, the second wireless device 1 transmits the measured received waveform to the processing device 6 through the network 5 (step S22).

  Next, the signal preprocessing unit 22 of the processing device 6 performs preprocessing of the input received waveform, and inputs the received waveform shaped into a waveform suitable for signal analysis to the feature value generating unit 23 (step S23). .

  This pre-processing is a noise removal process similar to step S14 described above. For example, there are a process for calculating a moving average, a process using a low-pass filter, a process for calculating an ensemble average of a plurality of received waveforms, etc. In the present embodiment, the signal preprocessing unit 22 of the processing device 6 It is preferred to calculate the ensemble average. Further, this signal pre-processing may be performed in the second radio device 1 when the second radio device 1 receives the UWB impulse radio signal 4. In this case, a general-purpose processor may be incorporated into the wireless device 1 and calculation may be performed by the general-purpose processor. However, a dedicated LSI including a circuit configuration suitable for the preprocessing function may be incorporated into the wireless device 1 and used. Is preferred.

  Next, the feature quantity generation unit 23 of the processing device 6 analyzes the input received waveform and extracts a second feature quantity (step S24). The feature quantity generation unit 23 outputs the second feature quantity extracted from the received waveform of the second moving object to the feature quantity comparison unit 24.

  Here, the elements of the feature vector to be extracted are as described above. In addition to the delay profile, for example, statistics such as signal average value, variance, median value, maximum value, minimum value, mode value, and signal Features such as spectrum, frequency values, calibration values, that is, a received waveform when there is no moving object in the space, a received waveform when a predetermined number of people are present in the space, and movement Difference value and correlation value with the received waveform etc. when the object is moving at a predetermined trajectory at a constant speed, difference value with the received waveform before a certain time, average value of the received waveform for the past several times, camera Although there are a difference value and a correlation value between an output value of a sensor other than a radio signal such as an image and a microphone and a received waveform, the same feature amount as that calculated in step S15 is used. In this case, a general-purpose processor may be incorporated in the wireless device 1 and calculation may be performed by the general-purpose processor. However, a dedicated LSI including a circuit configuration suitable for feature vector extraction may be incorporated in the wireless device 1 and used. Is preferred.

  In step S24, the feature amount comparison unit 24 of the processing device 6 obtains the second feature amount extracted from the received waveform of the second moving object. Next, the feature quantity comparison unit 24 refers to the correspondence data recorded in the database device 7, and has an entry of the first feature quantity whose distance between the feature quantities is the nearest to the second feature quantity. It is determined whether or not (step S25).

  Note that a technique according to the nearest neighbor determination rule is used for comparison of feature amounts. That is, the first feature quantity set recorded in the database device 7 is mapped onto the feature space, and the mapped first feature quantity and the newly obtained second feature quantity are displayed on the feature space. In this method, the nearest class is output as a matching result. Specifically, the Euclidean distance between all the first feature values and the newly obtained second feature value is calculated, and the entry of the first feature value with the smallest Euclidean distance is set as the second feature. Output as the feature quantity closest to the quantity. Further, a Mahalanobis distance, a correlation coefficient, a difference value, or the like may be used without using the Euclidean distance.

  Also, the correlation coefficient between the signal waveform of the second feature quantity and the first feature quantity output as being closest to the second feature quantity is calculated, and the correlation coefficient exceeds the threshold value Only in some cases, step S26 for outputting the coordinates of the terminal may be provided after step S25.

  If it is determined in step S25 that there is an entry for the first feature value that is closest to the second feature value, and if step S26 is set as necessary, the first feature value is then set. And the second feature quantity are calculated, and it is determined whether or not the calculated correlation coefficient exceeds a predetermined threshold (step S26). If it is determined in step S26 that the correlation coefficient exceeds the threshold, the position of the terminal device 2 described in the entry of the first feature value is output as the position of the second moving object (step S27). .

  The processing device 6 may calculate the movement path or speed of the second moving object by plotting the output position and time of the second moving object on the space 8. The calculation result may be recorded in the database device 7. Thereby, for example, it is possible to know whether the second moving object has stopped at a certain position for a certain period or in which direction it has moved.

  Further, when it is determined in step S25 that there is no entry of the first feature value that is the nearest to the second feature value, and the first feature that is the nearest in step S26 set as necessary. If it is determined that the correlation coefficient between the feature amount and the second feature amount does not exceed the predetermined threshold, it is determined that there is no first feature amount that matches the second feature amount, and the feature The amount comparison process is terminated.

  Note that if it can be determined in step S25 that the first feature value and the second feature value match with sufficient accuracy, step S26 is omitted, and the terminal device 2 described in the entry of the first feature value. May be output as the position of the second moving object.

  When the database device 7 is configured by a network that performs learning such as a neural network, the second feature value is an input value to the network, and the position of the terminal device 2 is an output value. It is preferable that the algorithm for checking the input / output values is configured so that it can be changed to adapt to the sensor or environment used. For example, the processing device 6 includes an algorithm for changing this by a human and an algorithm for minimizing a difference between the position measurement result of the terminal device 2 and the measurement result of the moving object including the terminal device 2 at that time. You may choose to adapt.

  Next, a method for measuring the position of the terminal device shown in step S10 of FIG. 6 will be described.

  FIG. 8 is a configuration diagram of a position measurement system for the terminal device 41 according to the first embodiment of the present invention.

  As a method for measuring the position of the terminal device 41, there are a recognition method using a moving image of a camera, a recognition method using ultrasonic waves, a method using an RFID or an IC chip, a method using radio other than UWB impulse radio, and the like. In the first embodiment of the present invention, a measurement method for determining the position of the terminal device 41 by measuring the propagation time of the radio signal transmitted by the terminal device 41 is used.

  Measurement methods using radio signal propagation time are broadly divided into TOA (Time of Arrival) and TDOA (Time Difference of Arrival). The former is a method of measuring the position of a terminal device from the propagation time of signals from the terminal device to a plurality of base station devices, and the latter is a method in which the base station receives a positioning signal from the terminal device and the position is known. In this method, the position of the terminal device is measured from the difference from the time at which the base station device receives a reference signal transmitted from a certain reference base station device. An impulse UWB radio signal can easily measure the propagation time compared to a continuous wave signal. Therefore, the positioning system using the impulse type UWB radio signal is suitable for measuring the position of the terminal device by either the TOA or TDOA method.

  The terminal location measurement system shown in FIG. 8 includes at least three base station devices 42 and a terminal location analysis device 45, which are connected by a network 44. The terminal device 41 has a function of transmitting a positioning signal 43. The base station apparatus 42 has a function of receiving the positioning signal 43 and is connected to the terminal position analysis apparatus 45 through the network 44. The base station apparatus 42 transmits the received positioning signal 43 to the position analysis apparatus 86. The terminal position analysis device 45 acquires each of the propagation times of the positioning signals 43 measured by at least three or more base station devices 42 via the network 44, and calculates the position of the terminal device 41 based on the acquired propagation times.

  As described above, according to the first embodiment of the present invention, the first feature amount of the received waveform including the delay profile is associated in advance with the position of the first moving object 3 to which the terminal device 41 is attached. In this case, it is difficult to attach sensors, wireless tags, communication terminal devices, etc. even in indoor spaces where it is difficult to obtain a line-of-sight environment between the wireless device and the moving object due to obstacles. The position can be measured and the movement can be detected without mounting.

<Embodiment 2>
The configuration of the positioning system according to the second embodiment of the present invention will be described.

  FIG. 9 is a configuration diagram of a positioning system according to the second embodiment of this invention.

  The base station device 42 and the terminal position analysis device 45 in the terminal device position measurement system shown in FIG. 8 may be the same as the radio device 1 and the processing device 6 in the positioning system shown in FIG. That is, the wireless device 1 of the positioning system can also serve as the function of the base station device 42 for measuring the position of the terminal device 41, and the processing device 6 can also serve as the function of the terminal location analysis device 45.

  The positioning system according to the second embodiment includes a terminal device 51, a base station device / radio device 52, a terminal location analysis device / processing device 55, and a database device 56, and each device is connected by a network 54. The terminal device 51 has a function of transmitting a positioning signal 53. The base station device / radio device 52 has a function of receiving a positioning signal 53, is connected to a terminal location analysis device / processing device 55 through a network 54, and transmits the received positioning signal 53 to the terminal location analysis device / processing device 55. To do. The terminal position analysis / processing device 55 acquires the propagation time of at least three positioning signals 53 received by the base station device / wireless device 52 through the network 54, and calculates the position of the terminal device 51 based on the propagation time. .

  The processing in the positioning system of the second embodiment is the same as the processing from step S10 to step S18 shown in FIG. 6 and the processing from step S20 to step S27 shown in FIG. 7, and is shown in step S10 in FIG. The terminal location measurement processing is performed by the base station device / radio device 52 and the terminal location analysis / processing device 55.

  As described above, the second embodiment of the present invention differs from the first embodiment in that the position measurement of the terminal device is performed by the radio device and the processing device that measure the received waveform. Thus, in the second embodiment, the system configuration can be simplified.

It is a block diagram of the positioning system of the 1st Embodiment of this invention. It is a block diagram which shows the structure of the radio | wireless machine of the 1st Embodiment of this invention. It is a block diagram which shows the structure of the processing apparatus of the 1st Embodiment of this invention. It is a conceptual diagram of the ensemble average calculation of the received waveform of the 1st Embodiment of this invention. It is a figure which shows the delay profile characteristic of the received waveform of the 1st Embodiment of this invention. It is a flowchart which shows the process which matches and records the terminal device positioning result and the feature-value of a received waveform of the 1st Embodiment of this invention. It is a flowchart which shows the process which outputs the position of the moving object of the 1st Embodiment of this invention. It is a block diagram of the terminal device positioning system of the 1st Embodiment of this invention. It is a block diagram of the positioning system of the 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Radio | wireless machine 2 Terminal apparatus 3 Moving object 4 UWB impulse radio signal 5 Network 6 Processing apparatus 7 Database apparatus 8 Space 11 Antenna 12 Signal generation control part 13 UWB impulse radio signal transmission part 14 Communication part 15 UWB impulse radio signal reception part 21 Communication Unit 22 signal preprocessing unit 23 feature quantity generation unit 24 feature quantity comparison unit 31 received waveform 32 received waveform 33 received waveform 34 ensemble average of received waveform 42 base station device 43 positioning signal 44 network 45 terminal location analysis device 52 serving as base station device Wireless device 53 Positioning signal 54 Network 55 Terminal position analyzing / processing device 56 Database device 57 Space 58 Moving object

Claims (16)

A positioning system that measures the position of a moving object using the analysis result of the waveform of the received signal,
A terminal position measuring device for measuring the position of the terminal device attached to the first moving object;
A first wireless device comprising at least a transmitter;
A second wireless device comprising at least a receiver;
A processing device for analyzing a waveform of a signal by a direct wave transmitted by the first wireless device and a reflected wave reflected by a first moving object, and generating a first analysis result;
A database that records the first analysis result generated by the processing device and the position of the first moving object;
The processor is
The terminal position measured by the terminal position measuring device and the first analysis result are associated with each other and recorded in the database,
When the waveform of the signal by the direct wave transmitted by the first wireless device and the reflected wave reflected by the second moving object is acquired, the second analysis result generated from the acquired waveform and the database Compared with the first analysis result recorded in
When it is determined that the second analysis result corresponds to the first analysis result, the position of the terminal device corresponding to the corresponding first analysis result is determined as the position of the second moving object. A positioning system characterized by that.   The positioning system according to claim 1, wherein the first and second wireless devices transmit and receive impulse UWB wireless signals. The first and second wireless devices include a transmitter and a receiver,
After the second wireless device receives the signal transmitted by the first wireless device, the second wireless device transmits the signal;
The first wireless device receives a signal transmitted by the second wireless device;
The positioning system according to claim 1, wherein the processing device generates the second analysis result from reception waveforms of signals received by the first and second wireless devices. The processor is
A signal processing unit for converting the received waveform into data suitable for analysis;
Analyzing the converted data, generating a feature value as an analysis result, and recording the generated feature value in a database; and
A feature amount comparison unit that compares the feature amounts by calculating a distance between the generated feature amounts; and
The feature quantity generation unit records the position of the terminal device measured by the terminal position measurement device and the first feature quantity in association with each other in the database,
When the received waveform is acquired, the feature value comparing unit compares a distance between the second feature value generated from the acquired received waveform and the first feature value recorded in the database. 2. The positioning system according to claim 1, wherein the first feature value that is closest to the second feature value is selected from a feature space.   The positioning system according to claim 4, wherein the feature quantity generation unit generates the feature quantity from a delay profile of the received waveform.   When the correlation between the first feature quantity selected as being closest to the second feature quantity and the second feature quantity does not exceed a predetermined threshold, 5. The positioning system according to claim 4, wherein it is determined that the first feature amount corresponding to the second feature amount is not in the database.   The positioning system according to claim 1, wherein the signal processing unit converts the received waveform into data suitable for analysis by calculating an ensemble average. The terminal position measuring device includes at least three receivers,
2. The positioning system according to claim 1, wherein the position of the terminal device attached to the first moving object is measured using an impulse-type UWB radio signal received by each receiver.   The positioning system according to claim 8, wherein the receiver is the second wireless device.   The processing device repeatedly records the position of the second moving object measured by comparing the first analysis result and the second analysis result, and calculates the movement path of the second moving object. The positioning system according to claim 1, wherein A processing device provided in a positioning system that measures the position of a moving object using the analysis result of the waveform of a received signal,
The positioning system is
A terminal position measuring device for measuring the position of the terminal device attached to the first moving object;
A first wireless device comprising at least a transmitter;
A second wireless device comprising at least a receiver;
A database that records the first analysis result generated by the processing device and the position of the first moving object;
The processor is
Analyzing the waveform of the signal from the direct wave transmitted by the first wireless device and the reflected wave reflected by the first moving object to generate a first analysis result;
The terminal position measured by the terminal position measuring device and the first analysis result are associated with each other and recorded in the database,
When the waveform of the signal by the direct wave transmitted by the first wireless device and the reflected wave reflected by the second moving object is acquired, the second analysis result generated from the acquired waveform and the database Compared with the first analysis result recorded in
When it is determined that the second analysis result corresponds to the first analysis result, the position of the terminal device corresponding to the corresponding first analysis result is determined as the position of the second moving object. The processing apparatus characterized by the above-mentioned. A signal processing unit for converting the received waveform into data suitable for analysis;
Analyzing the converted data, generating a feature value as an analysis result, and recording the generated feature value in a database; and
A feature amount comparison unit that compares the feature amounts by calculating a distance between the generated feature amounts; and
The feature quantity generation unit records the position of the terminal device measured by the terminal position measurement device and the first feature quantity in association with each other in the database,
When the received waveform is acquired, the feature value comparing unit compares a distance between the second feature value generated from the acquired received waveform and the first feature value recorded in the database. The processing apparatus according to claim 11, wherein the first feature value that is closest to the second feature value is selected from a feature space.   The processing apparatus according to claim 12, wherein the feature quantity generation unit generates the feature quantity from a delay profile of the received waveform.   When the correlation between the first feature value selected as being closest to the second feature value and the second feature value does not exceed a predetermined threshold, The processing apparatus according to claim 12, wherein the first feature amount corresponding to the second feature amount is determined not to be in the database.   The processing apparatus according to claim 12, wherein the signal processing unit converts the received waveform into data suitable for analysis by calculating an ensemble average.   The position of the second moving object measured by comparing the first analysis result and the second analysis result is repeatedly recorded, and the movement path of the second moving object is calculated. 11. The processing apparatus according to 11.

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