JP2022023570A - Position specifying device - Google Patents

Abstract

To reduce the number of antennas needed for estimating the position of a tag and/or improve the accuracy of estimating the position of the tag.SOLUTION: The position specifying device comprises: a detection unit 31 for detecting a moving object that is currently moving on the basis of a plurality of imaged images generated by an imaging unit 1 that generates imaged images in the surroundings of an antenna 2; an acquisition unit 32 for acquiring, via the antenna 2, identification information that identifies a tag; a measurement unit 33 for measuring the radio wave intensity of the radio wave received from the tag by the antenna 2; and a specification unit 36 for associating, on the basis of a correlation between a change mode of the radio wave intensity measured by the measurement unit 33 and a change mode of the position of the moving object detected by the detection unit 31, identification information corresponding to a tag whose radio wave intensity changes with the moving object and specifying the position in the imaged image of the moving object associated to the identification information as the position of the tag.SELECTED DRAWING: Figure 3

Description

The present invention relates to a position specifying device for specifying the position of a tag.

The position of the tag is estimated by using short-range wireless communication such as RFID (for example, Patent Document 1). In Patent Document 1, a plurality of RFID reader antennas are arranged so that tag detection areas overlap each other, and when a plurality of RFID reader antennas detect one tag at the same time, the tag detection areas overlap in the overlapping area. It is stated that any position is considered to be the position of this tag.

Japanese Unexamined Patent Publication No. 2006-275839

The method described in Patent Document 1 requires a plurality of RFID reader antennas for estimating the position of the tag, and has a problem that the estimation accuracy of the tag position is low.

The present invention has been made in view of the above problems, and is a position specifying device capable of reducing the number of antennas required for estimating the position of a tag and improving the estimation accuracy of the position of a tag. The purpose is to provide.

The position specifying device according to the first aspect of the present invention includes a detection unit that detects a moving moving object based on a plurality of the captured images generated by the imaging unit that generates an image captured around the antenna, and the antenna. An acquisition unit that acquires identification information for identifying the tag, a measurement unit that measures the radio wave intensity of the radio wave received from the tag by the antenna, and a change mode of the radio wave intensity measured by the measurement unit. Based on the correlation with the change mode of the position of the moving body detected by the detection unit, the identification information corresponding to the tag whose radio wave intensity changes is associated with the moving body and associated with the identification information. It also includes a specific portion that specifies the position of the moving body in the captured image as the position of the tag.

The specific unit further includes a determination unit for determining whether or not there is a correlation between the change mode of the radio wave intensity measured by the measurement unit and the change mode of the position of the moving body detected by the detection unit. When the determination unit determines that the change mode of the radio wave intensity of the radio wave received from the tag and the change mode of the position of the moving body have a correlation, the identification corresponding to the tag whose radio wave strength changes. The information may be associated with the moving object.

When the determination unit determines that the change mode of the radio wave intensity corresponding to a predetermined number of identification information and the change mode of the position of the moving body have a correlation, the position specifying device receives the radio wave from the antenna. A radio wave control unit for stopping irradiation may be further provided. The determination unit determines whether or not there is a correlation between the change mode of the radio wave intensity and the change mode of the position of the moving object detected by the detection unit in descending order of the radio wave intensity of the radio wave received from the tag. You may.

When the moving body associated with the identification information acquired by the acquisition unit from the tag passes through the gate configured by the antenna in the captured image, the tag passes through the gate. You may specify that. The detection unit detects that the orientation of the moving body has changed in the captured image, and the determination unit detects that the orientation of the moving body has changed when the detection unit detects that the orientation of the moving body has changed. The determination as to whether or not there is a correlation between the change mode of the position of the radio wave intensity and the change mode of the radio wave intensity may be executed again.

According to the present invention, there is an effect of reducing the number of antennas required for estimating the position of the tag or improving the estimation accuracy of the position of the tag.

It is a figure for demonstrating the outline of the position specifying apparatus of an embodiment. It is a figure for demonstrating the outline of the position specifying apparatus of an embodiment. It is a figure which shows the structure of the position specifying apparatus. It is a figure for demonstrating the determination method of the correlation by the determination unit. It is a flowchart which shows the processing procedure of the position identification of a tag by a position specifying device.

[Overview of position identification device]
1 and 2 are diagrams for explaining an outline of the position specifying device 100 of the present embodiment. FIG. 1 shows the configuration of the position specifying device 100. The position specifying device 100 identifies the position of a tag for short-range wireless communication such as RFID (Radio Frequency Identification). The position specifying device 100 is installed, for example, near the entrance / exit of the truck bed. The position specifying device 100 may be installed near the doorway of the warehouse.

The position specifying device 100 includes an image pickup unit 1, an antenna 2, and a control unit 3. The image pickup unit 1 generates a captured image around the antenna 2. The antenna 2 is a communication element for performing short-range wireless communication. FIG. 2 is a diagram showing a state during short-range wireless communication by the antenna 2.

FIG. 2 shows a state in which a load with a tag 300 is loaded on the loading platform of a truck on which the position specifying device 100 is mounted. The antenna 2 performs short-range wireless communication with the tag 300. In the example of the present specification, the antenna 2 performs short-range wireless communication with the tag 300 by the RFID method.

The control unit 3 in FIG. 1 detects a moving object based on a plurality of captured images captured by the image pickup unit 1. The moving body is, for example, a person, a trolley, or a forklift that carries a box or clothing on which the tag 300 is supposed to be attached, a box to which the tag is attached, or the like. The control unit 3 acquires the identification information that identifies the tag 300 via the antenna 2. The control unit 3 sequentially measures the radio wave intensity of the radio wave received from the tag 300. The control unit 3 determines whether or not there is a correlation between the detected change mode of the position of the moving body and the change mode of the radio wave intensity of the radio wave received from the tag 300. When the control unit 3 determines that the detected change mode of the position of the mobile body and the change mode of the radio wave intensity have a correlation, the control unit 3 stores the mobile body and the identification information of the tag 300 in the storage unit in association with each other. .. The control unit 3 identifies the position in the captured image of the moving body associated with the identification information as the position of the tag 300 in which the identification information is stored.

The control unit 3 determines whether or not the tag 300 has passed through the gate configured by the antenna 2 by tracking the position of the moving object associated with the identification information of the tag 300 on the captured image. The control unit 3 may output a list of identification information of the tag 300 that identifies that it has passed through the gate to the wireless terminal 200 by wireless communication. The wireless terminal 200 may display a list of identification information of the tag 300 received from the position specifying device 100 on a display (not shown). Further, the control unit 3 may output the list of the identification information of the tag 300 to the vehicle as it is by wire. When the position specifying device 100 is installed in a factory or the like, the control unit 3 may output the list of identification information of the tag 300 as it is to a server (not shown) in the factory by wire.

In this way, the control unit 3 identifies the position of the tag 300 with reference to the radio wave intensity of the radio wave received from the tag 300 and the position of the moving body on the captured image. Therefore, as compared with the case where the control unit 3 specifies the position of the tag 300 using only the radio wave intensity of the radio wave received from the tag 300, the control unit 3 is a mobile body to which the tag 300 is attached even if the number of antennas 2 is small. The position can be specified. The control unit 3 can improve the accuracy of specifying the position of the moving body to which the tag 300 is attached.

[Configuration of position identification device]
FIG. 3 is a diagram showing the configuration of the position specifying device 100. The position specifying device 100 includes an image pickup unit 1, an antenna 2, a control unit 3, a communication unit 4, and a storage unit 5. The control unit 3 includes a detection unit 31, an acquisition unit 32, a measurement unit 33, a determination unit 34, a radio wave control unit 35, a specific unit 36, and an output unit 37.

The image pickup unit 1 generates a captured image around the antenna 2. The image pickup unit 1 generates a captured image at predetermined time intervals. The predetermined time is, for example, 1/100 second to 1/10 second. A plurality of image pickup units 1 may generate captured images. The image pickup unit 1 inputs the generated captured image to the detection unit 31.

The antenna 2 is a communication element for performing short-range wireless communication. The antenna 2 can communicate with the plurality of tags 300 by assigning different time slots to the plurality of tags 300. The antenna 2 receives the identification information that identifies the tag 300 from the tag 300. The antenna 2 inputs the received identification information to the acquisition unit 32.

The communication unit 4 may communicate with the wireless terminal 200 by wireless communication such as Wi-Fi (registered trademark). The communication unit 4 may communicate with the wireless terminal 200 via a wireless communication line such as LTE. The communication unit 4 may transmit, for example, a list of identification information of the tag 300 that has passed through the gate to the wireless terminal 200. Further, the communication unit 4 may communicate with the vehicle by wire. For example, the communication unit 4 may transmit a list of identification information of the tag 300 that has passed through the gate to the vehicle by wire. When the position specifying device 100 is installed in a factory or the like, the communication unit 4 may communicate with a server in the same factory, or may output a list of identification information of the tag 300 to the server by wire.

The storage unit 5 is composed of, for example, a ROM (Read Only Memory), a RAM (Random Access Memory), or the like. The storage unit 5 stores various programs and various data for operating the control unit 3. The control unit 3 is, for example, a CPU (Central Processing Unit). The control unit 3 functions as a detection unit 31, an acquisition unit 32, a measurement unit 33, a determination unit 34, a radio wave control unit 35, a specific unit 36, and an output unit 37 by executing a program stored in the storage unit 5. ..

The detection unit 31 detects a moving moving object based on a plurality of captured images generated by the imaging unit 1. The detection unit 31 detects a moving object by detecting the difference between a plurality of captured images.

As shown in FIG. 2, when a plurality of cargoes with a plurality of tags 300 are carried by a forklift or the like, the plurality of tags 300 move as one. At this time, if the detection unit 31 individually detects the box with each tag 300 as a moving body, the detection accuracy is lowered, so that the entire forklift or the fork portion supporting the load with the tag 300 is supported. Is detected as one moving body. The detection unit 31 outputs information indicating the position of the detected moving object to the determination unit 34.

The detection unit 31 detects that the orientation of the moving object has changed in the captured image. For example, the detection unit 31 detects that the worker has rotated the load when loading the load with the tag 300 on the truck bed. The detection unit 31 outputs information indicating whether or not the moving body has changed its direction to the determination unit 34.

The acquisition unit 32 acquires the identification information that identifies the tag 300 via the antenna 2. In the example of the present specification, it is assumed that the acquisition unit 32 can acquire the identification information from each of the plurality of tags 300. The acquisition unit 32 outputs the acquired identification information to the measurement unit 33 and the determination unit 34.

The measuring unit 33 measures the radio wave intensity of the radio wave received from the tag 300 by the antenna 2. The measuring unit 33 measures the radio field intensity corresponding to the plurality of identification information acquired by the acquisition unit 32, respectively. The measuring unit 33 measures the radio wave intensity at predetermined time intervals. The predetermined time is, for example, the same as the cycle of generating the captured image by the imaging unit 1. The measurement unit 33 outputs the measurement result of the radio wave intensity to the determination unit 34.

[Correlation judgment]
The determination unit 34 determines whether or not there is a correlation between the change mode of the radio wave intensity measured by the measurement unit 33 and the change mode of the position of the moving body detected by the detection unit 31. FIG. 4 is a diagram for explaining a method of determining the correlation by the determination unit 34. FIG. 4A shows an image captured by the image pickup unit 1, and FIG. 4B shows a change mode of the radio wave intensity measured by the measurement unit 33. As shown by the arrow in FIG. 4A, it is assumed that the package with the tag 300 is transported. The positions of the moving objects detected by the detection unit 31 at the timings A to D are indicated by black circles. At this time, the determination unit 34 sequentially calculates the distance from the tag 300 to the antenna 2 based on the position of the moving body detected by the detection unit 31. In the example of FIG. 4, the determination unit 34 calculates the distances from the tag 300 to the antennas 2 on both sides of the tag 300, respectively.

The horizontal axis of FIG. 4B shows time, and the vertical axis of FIG. 4B shows the radio wave intensity of the radio wave received from the tag 300. The measured value measured by the measuring unit 33 for the radio wave intensity of the radio wave from the tag 300 is shown by a solid line. Timings A to D are shown on the horizontal axis.

It is assumed that the change mode of the position of the moving body and the change mode of the radio wave intensity received from the tag 300 have a correlation. At this time, the determination unit 34 is based on the measured value of the radio wave intensity of the tag 300 measured by the measurement unit 33 before the tag 300 moves and the distance from the tag 300 to the antennas 2 on both sides of the tag 300. The estimated value of the radio wave strength of the radio wave received by the antenna 2 is obtained from 300. In FIG. 4B, the assumed value of the radio wave intensity obtained by the determination unit 34 is shown by a broken line.

The determination unit 34 has a radio wave intensity measured by the measurement unit 33 based on the difference between the measured value measured by the measurement unit 33 for the radio wave intensity of the radio wave from the tag 300 and the assumed value of the radio wave intensity obtained by the determination unit 34. It is determined whether or not there is a correlation between the change mode of the moving body and the change mode of the position of the moving body. FIG. 4B shows the difference between the measured value of the radio field intensity and the assumed value of the radio wave strength at timings A to D, respectively, with double-headed arrows.

For example, the determination unit 34 determines the change mode of the radio wave strength and the position of the moving body when the sum of the differences between the measured value of the radio wave strength and the assumed value of the radio wave strength at a plurality of timings A to D is equal to or less than the allowable value. It is determined that there is a correlation with the change mode of. The permissible value is determined by those skilled in the art, for example, according to the required accuracy of the determination.

On the other hand, the determination unit 34 changes the radio wave intensity when the sum of the differences between the measured value of the radio wave intensity and the assumed value of the radio wave intensity obtained by the determination unit 34 at a plurality of timings A to D exceeds the permissible value. It is determined that there is no correlation between the change mode and the change mode of the position of the moving body.

When the detection unit 31 detects a moving object such as a forklift carrying a load with a plurality of tags 300, the position of one moving object and the radio field strength received from the plurality of tags 300 correlate with each other. May have. Therefore, when the acquisition unit 32 acquires a plurality of identification information, the determination unit 34 changes the position of one moving object detected by the detection unit 31 and changes in the radio wave intensity corresponding to each of the plurality of identification information. It is determined whether or not the aspect has a correlation.

[Change in tag orientation]
When the tag 300 emits a radio wave by a linearly polarized antenna, when the direction of the tag 300 changes, the radio wave intensity of the radio wave received from the tag 300 by the antenna 2 changes. When the tag 300 emits a radio wave by a circularly polarized antenna, the influence on the radio wave intensity of the radio wave received by the antenna 2 is small even if the direction of the tag changes. However, the reflection or attenuation of radio waves due to the luggage to which the tag 300 is attached, the reflection of radio waves due to surrounding metal products, etc. may change depending on the direction of the tag 300, and the radio wave intensity of the radio waves received by the antenna 2 may change. be. In this case, the determination unit 34 may erroneously determine whether or not there is a correlation between the change mode of the position of the moving body and the change mode of the radio wave intensity.

Therefore, when the detection unit 31 detects that the orientation of the moving body has changed, the determination unit 34 determines whether or not there is a correlation between the change mode of the position of the moving body and the change mode of the radio wave intensity. Interrupt and re-execute the same decision. In this way, the determination unit 34 erroneously determines whether or not there is a correlation between the change mode of the position of the moving body and the change mode of the radio wave intensity due to the change in the orientation of the tag 300. Can be suppressed. Alternatively, the determination unit 34 may consider the influence of the change in radio wave intensity due to the change in the orientation of the tag in determining whether or not the change mode of the position of the moving body and the change mode of the radio wave intensity have a correlation. If possible, the determination of the correlation may be continued as it is.

The radio wave strength of the radio wave received from the tag 300 located near the antenna 2 is likely to be higher than the radio wave strength received from the tag 300 located far from the antenna 2. The determination unit 34 determines whether or not there is a correlation between the change mode of the radio wave intensity and the change mode of the position of the moving object detected by the detection unit 31 in descending order of the radio wave intensity of the radio wave received from the tag 300. In this way, the determination unit 34 determines whether or not there is a correlation between the change mode of the radio wave intensity of the radio wave received from the tag 300 and the change mode of the position of the moving body detected by the detection unit 31. The determination of the tag 300 located near the antenna 2 can be prioritized over the tag 300 located far from the antenna 2.

The radio wave control unit 35 irradiates the tag 300 with a radio wave for short-range wireless communication by the antenna 2, or stops irradiating the tag 300 with the radio wave by the antenna 2. For example, the radio wave control unit 35 starts irradiating radio waves when the open / close sensor (not shown) detects that the door of the truck bed has been opened. For all the identification information acquired by the acquisition unit 32, the radio wave control unit 35 determines whether or not there is a correlation between the change mode of the radio wave intensity of the radio wave received from the tag 300 corresponding to the identification information and the position mode of the moving body. After the determination unit 34 makes the determination, the irradiation of the radio wave to the tag 300 by the antenna 2 is stopped.

Further, when the radio wave control unit 35 determines that the change mode of the radio wave intensity corresponding to a predetermined number of identification information and the change mode of the position of the moving body have a correlation, the radio wave from the antenna 2 is transmitted. Irradiation may be stopped. The predetermined number is determined according to, for example, the battery capacity of the truck on which the position specifying device 100 is mounted. As an example, when the radio wave control unit 35 determines that the change mode of the radio wave intensity corresponding to the 10 identification information and the change mode of the position of the moving body have a correlation, the antenna 2 Stop the irradiation of radio waves from.

[Identify the position of the tag]
The identification unit 36 identifies the tag 300 whose radio wave intensity changes based on the correlation between the change mode of the radio wave intensity measured by the measurement unit 33 and the change mode of the position of the moving body detected by the detection unit 31. The information and the moving body are associated with each other and stored in the storage unit 5. When the determination unit 34 determines that the change mode of the radio wave intensity of the radio wave received from the tag 300 and the change mode of the position of the moving body detected by the detection unit 31 have a correlation, the moving body detected by the detection unit 31 is selected. It can be considered that this tag 300 is attached. When the determination unit 34 determines that the change mode of the radio wave intensity of the radio wave received from the tag 300 and the change mode of the position of the detected moving object have a correlation, the specific unit 36 changes the radio wave strength of the tag 300. The identification information corresponding to is associated with the moving body and stored in the storage unit 5.

After that, the identification unit 36 sequentially identifies the position on the captured image of the moving body similar to the moving body associated with the identification information of the tag 300 in the storage unit 5. The specifying unit 36 specifies the position of the specified moving object in the captured image as the position of the tag 300.

The specific unit 36 sequentially tracks the moving body associated with the identification information acquired by the acquisition unit 32 from the tag 300 in the storage unit 5 on the captured image. The identification unit 36 identifies that the tag 300 has passed through the gate when the moving object being tracked has passed through the gate configured by the antenna 2 in the captured image. In this way, since the specific unit 36 determines whether or not the tag 300 has passed through the gate by referring to the captured image, the tag 300 gates using only the radio wave strength of the radio wave received from the tag 300. It is possible to suppress an error in the determination as compared with the case of determining whether or not the vehicle has passed. The identification unit 36 generates a list of identification information of the tag 300 that identifies that it has passed through the gate. The specific unit 36 notifies the output unit 37 of the generated list.

The output unit 37 communicates with the wireless terminal 200 by the communication unit 4. The output unit 37 may output a list of identification information of the tag 300 specified by the specific unit 36 that it has passed through the gate to the wireless terminal 200. Further, the output unit 37 may output the list of the identification information of the tag 300 specified by the specific unit 36 that it has passed through the gate to the vehicle as it is by wire. When the position specifying device 100 is installed in a factory or the like, the output unit 37 outputs a list of identification information of the tag 300 specified by the specific unit 36 that it has passed through the gate as it is to a server in the factory by wire. May be good.

[Processing procedure for specifying the position of the tag]
FIG. 5 is a flowchart showing a processing procedure for specifying the position of the tag 300 by the position specifying device 100. For example, this processing procedure is started when the radio wave control unit 35 irradiates a radio wave for short-range wireless communication from the antenna 2.

First, the imaging unit 1 starts generating an captured image (S101). Next, the detection unit 31 detects a moving moving object based on the plurality of captured images generated by the imaging unit 1 (S102). The acquisition unit 32 acquires the identification information that identifies the tag 300 via the antenna 2 (S103). The measuring unit 33 measures the radio wave strength of the radio wave received from the tag 300 by the antenna 2 (S104). The determination unit 34 determines whether or not there is a correlation between the change mode of the radio wave intensity measured by the measurement unit 33 and the change mode of the position of the moving body detected by the detection unit 31 (S105).

When the determination unit determines that the change mode of the radio wave intensity measured by the measurement unit 33 and the change mode of the position of the moving body detected by the detection unit 31 have a correlation (YES in S105). , The storage unit 5 stores a table in which the identification information corresponding to the tag 300 whose radio wave intensity changes and the moving body are associated with each other (S106). The specific unit 36 reads the table from the storage unit 5. The identification unit 36 specifies the position of the tag 300 corresponding to the identification information by sequentially specifying the position of the moving body similar to the moving body associated with the identification information in the captured image (S107). The output unit 37 determines whether or not there is a correlation between the change mode of the radio wave intensity of the tag 300 corresponding to the identification information and the change mode of the position of the moving body for all the identification information acquired by the acquisition unit 32. It is determined whether or not 34 has determined (S108).

When the determination unit 34 determines whether or not there is a correlation between the change mode of the radio wave intensity and the change mode of the position of the moving body for all the identification information, the output unit 37 is the image pickup unit (YES in S108). In the captured image generated by 1, the identification information of the tag 300 having a correlation with each moving body may be attached to the positions of the plurality of moving bodies detected by the detection unit 31 and output (S109). For example, the output unit 37 may transmit the captured image with the identification information to the wireless terminal 200 by wireless communication and output it to the display of the wireless terminal 200. Further, the output unit 37 may transmit the captured image with the identification information to the vehicle by wire and output it to the display of the vehicle. When the position specifying device 100 is installed in a factory, the output unit 37 may output the captured image to a server installed in the same factory by wire. The radio wave control unit 35 stops the irradiation of the radio wave from the antenna 2 (S110), and ends the process.

In the specific unit 36, the determination unit determines that the change mode of the radio wave intensity measured by the measurement unit 33 in the determination of S105 and the change mode of the position of the moving body detected by the detection unit 31 do not have a correlation. In the case (NO of S105), the process proceeds to S108. When the output unit 37 does not determine whether or not the change mode of the radio wave intensity and the change mode of the position of the moving body have a correlation with respect to a part of the identification information acquired by the acquisition unit 32. (NO in S108), the process returns to S102.

[Effect of the position specifying device of this embodiment]
According to the present embodiment, the specifying unit 36 specifies the position of the tag 300 with reference to the radio wave intensity of the radio wave received from the tag 300 and the position of the moving body on the captured image. Therefore, as compared with the case where the position of the tag 300 is specified by using only the radio wave intensity of the radio wave received from the tag 300, the specifying unit 36 is a moving body to which the tag 300 is attached even if the number of antennas 2 is small. The position can be specified. The identification unit 36 can improve the accuracy of specifying the position of the tag 300.

Although the present invention has been described above using the embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments, and various modifications and changes can be made within the scope of the gist. be. For example, all or part of the device can be functionally or physically distributed / integrated in any unit. Also included in the embodiments of the present invention are new embodiments resulting from any combination of the plurality of embodiments. The effect of the new embodiment produced by the combination has the effect of the original embodiment together.

1 Imaging unit 2 Antenna 3 Control unit 4 Communication unit 5 Storage unit 31 Detection unit 32 Acquisition unit 33 Measurement unit 34 Judgment unit 35 Radio control unit 36 Specific unit 37 Output unit 100 Position identification device 200 Wireless terminal 300 Tag

Claims (6)

A detection unit that detects a moving object based on a plurality of the captured images generated by the imaging unit that generates an image captured around the antenna, and a detection unit.
An acquisition unit that acquires identification information that identifies a tag via the antenna,
A measuring unit that measures the radio wave strength of the radio wave received by the antenna from the tag, and
The identification information corresponding to the tag whose radio wave intensity changes based on the correlation between the change mode of the radio wave intensity measured by the measuring unit and the change mode of the position of the moving body detected by the detection unit. And the moving body, and a specific portion that specifies the position of the moving body in the captured image associated with the identification information as the position of the tag.
A positioning device. Further, a determination unit for determining whether or not there is a correlation between the change mode of the radio wave intensity measured by the measurement unit and the change mode of the position of the moving body detected by the detection unit is provided.
The tag whose radio wave intensity changes when the determination unit determines that the change mode of the radio wave intensity of the radio wave received from the tag and the change mode of the position of the moving body have a correlation with the specific unit. The identification information corresponding to the above is associated with the moving object.
The position specifying device according to claim 1. When the determination unit determines that there is a correlation between the change mode of the radio wave intensity corresponding to a predetermined number of identification information and the change mode of the position of the moving body, the radio wave for stopping the irradiation of the radio wave from the antenna. Further equipped with a control unit,
The position specifying device according to claim 2. The determination unit determines whether or not there is a correlation between the change mode of the radio wave intensity and the change mode of the position of the moving object detected by the detection unit in descending order of the radio wave intensity of the radio wave received from the tag. do,
The position specifying device according to claim 3. When the moving body associated with the identification information acquired by the acquisition unit from the tag passes through the gate configured by the antenna in the captured image, the tag passes through the gate. To identify that,
The position specifying device according to any one of claims 2 to 4. The detection unit detects that the orientation of the moving body has changed in the captured image, and detects that the orientation of the moving body has changed.
When the detection unit detects that the orientation of the moving body has changed, the determination unit determines whether or not there is a correlation between the change mode of the position of the moving body and the change mode of the radio wave intensity. To run again,
The position specifying device according to any one of claims 2 to 5.

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