JP5928036B2 - Tag position estimation system, tag position estimation method, and tag position estimation program - Google Patents

Description

  The present invention relates to a tag position estimation system, a tag position estimation method, and a tag position estimation program.

  Conventionally, a passive tag such as an RFID tag is laid on the floor or the like, a tag reader that detects RFID is attached to a person's shoe sole, etc., and an ID read by the tag reader is transmitted to a server by wireless or the like to Attempts have been made to detect. The server stores data in which the tag ID and the coordinate position are associated one-on-one in advance, and the position can be obtained by referring to the coordinates corresponding to the detected tag ID. Examples of places where these technologies are applied include medical and nursing care sites, entertainment facilities such as museums, and companies that have a need to know the positions of employees.

  Tags such as RFID are inexpensive and can be laid on the floor in large quantities and with high density. As a result, the server can estimate the position of the person with high spatial resolution. However, for that purpose, it is necessary for the server to store correspondence data obtained by measuring the individual position coordinates of the tag in advance by some method. Measuring the position of a large number of tags requires a great deal of labor and increases the laying cost.

  On the other hand, a position detection device for an ID tag group that accumulates position information of a plurality of ID tags read at once by an ID tag reader, searches for a common ID tag from these, and estimates the position of the ID tag is known. ing.

JP 2010-8237 A

  However, the above-described conventional position detection device is based on the premise that the position information of a plurality of ID tags is read at a time, and unless the scene where the tag is laid at a high density or the tag can be detected in a wide range, There are cases where the tag position cannot be estimated with high accuracy. In particular, when the reading unit reads only the position information of one ID tag at a time, the accuracy may decrease depending on the movement mode of the reading unit.

  In one aspect, an object of the present invention is to estimate the position of a tag with high accuracy regardless of the movement mode of a reading unit.

According to one embodiment of the present invention, a tag ID reading unit that is attached to a mobile body and detects an ID tag installed in a communicable range and that can read ID information held by the detected ID tag, and the tag A storage unit in which ID information read by the ID reading unit is stored in association with a detection time when the corresponding ID tag is detected; a sensor unit for detecting a moving speed of the tag ID reading unit; A correction unit that corrects the detection time interval stored in the storage unit based on the moving speed of the tag ID reading unit obtained based on the output of the sensor unit, and a detection time interval corrected by the correction unit are used. Te, based on the relative position estimating unit that estimates a relative position of each tag, the relative position of each tag estimated by the relative position estimating unit, and the measured value of the three tags entered, absolute of each tag An absolute position estimation unit for estimating the position, a tag position estimation system comprising a.

  According to one embodiment, the position of the tag can be estimated with high accuracy regardless of the movement mode of the reading unit.

It is a figure which shows notionally the tag position estimation system 1 which concerns on 1st Example of this invention. It is a figure which shows a mode that many RFID tags 10 were laid by the floor surface. It is a figure which shows a mode that the RFID reader | leader 20 was attached to the bottom face of clogs. 2 is a hardware configuration example of a server 40. It is an example of functional composition of tag position presumption system 1 concerning the 1st example. It is a figure which shows ID information and detection time which were collected when a certain person walked. It is a figure for demonstrating the process which calculates an average time interval from the information after correction | amendment. It is a figure for demonstrating the process which estimates the relative position of RFID tag # 0001- # 0003. It is a figure for demonstrating the process which estimates the relative position of RFID tag # 0001- # 0004. It is a figure which shows a mode that the relative position of RFID tag 10 is calculated | required based on the average time interval calculated | required from the movement history of a certain person. It is a figure for demonstrating the process which superimposes the relative position of the RFID tag. Furthermore, it is a figure for demonstrating the process superimposed on the relative position of the RFID tag 10 calculated | required from the movement history of the other person. It is a figure which shows typically a mode that three points | pieces are selected among relative position coordinates, and an actual value is input. It is a figure which shows typically a mode that an absolute position coordinate is obtained from a relative position coordinate. It is a figure which shows typically a mode that the time interval correction | amendment part 42 converts into a time interval after correction | amendment the time interval when the RFID tag 20 was actually detected. It is an example of the flowchart which shows the flow of the process performed by the tag position estimation system 1 of 1st Example. It is a functional structural example of the tag position estimation system 2 which concerns on 2nd Example. It is an example of the flowchart which shows the flow of the process performed by the tag position estimation system 2 of 2nd Example. It is a functional structural example of the tag position estimation system 3 which concerns on 3rd Example. It is a figure for demonstrating the effect by the tag position estimation system 3 which concerns on 3rd Example. It is an example of the flowchart which shows the flow of the process performed by the tag position estimation system 3 of 3rd Example.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described with reference to the accompanying drawings.

<First embodiment>
Hereinafter, a tag position estimation system, a tag position estimation method, and a tag position estimation program according to a first embodiment of the present invention will be described with reference to the drawings.

[Hardware configuration]
FIG. 1 is a diagram conceptually showing a tag position estimation system 1 according to a first embodiment of the present invention. The tag position estimation system 1 includes, for example, a plurality of RFID tags 10 laid on the floor, an RFID reader 20 attached to the bottom of a person's footwear, a wireless LAN access point 30, and a server 40.

  FIG. 2 is a diagram illustrating a state in which a large number of RFID tags 10 are laid on the floor surface. The tag position estimation system 1 according to the present embodiment estimates the positions of such a large number of RFID tags 10 based on information collected according to the movement of a person. Each RFID tag 10 holds ID information, which is unique identification information. When the RFID tag 10 falls within the communicable range of the RFID reader 20, the RFID tag 10 returns passively using the radio wave transmitted by the RFID reader 20 as an energy source. It is a tag.

  FIG. 3 is a diagram illustrating a state in which the RFID reader 20 is attached to the bottom surface of the clog. The RFID reader 20 has a function of reading the ID information from the RFID tag 10 and transmitting the read ID information to the wireless LAN access point 30 together with the detection time when the RFID tag 10 is detected.

  FIG. 4 is a hardware configuration example of the server 40. The server 40 includes, for example, a CPU (Central Processing Unit) A, a drive device B, an auxiliary storage device D, a memory device E, an interface device F, an input device G, and a display device H. These components are connected via a bus, a serial line, or the like. Further, the server 40 may include a timer, a DMA (Direct Memory Access) controller, an interrupt controller, etc., not shown.

  The CPUA is a processor having, for example, a program counter, an instruction decoder, various arithmetic units, an LSU (Load Store Unit), a general-purpose register, and the like. The drive device B is a device that can read programs and data from the storage medium C. When the storage medium C on which the program is recorded is loaded into the drive device B, the program is installed from the storage medium C to the auxiliary storage device D via the drive device B. The storage medium C is a portable storage medium such as a CD (Compact Disc), a DVD (Digital Versatile Disc), or a USB (Universal Serial Bus) memory. The auxiliary storage device D is, for example, an HDD (Hard Disk Drive) or a flash memory.

  In addition to using the storage medium C as described above, the program can be installed by the interface device F being downloaded from another computer via a network and installed in the auxiliary storage device D. The network is the Internet, a LAN (Local Area Network), a wireless network, or the like. The program may be stored in advance in an auxiliary storage device D, a ROM (Read Only Memory), or the like when the server 10 or the server 100 is shipped.

  When the CPUA executes the program installed or stored in advance as described above, the information processing apparatus having the mode shown in FIG. 4 can function as the server 40 of this embodiment.

  The memory device E is, for example, a RAM (Random Access Memory) or an EEPROM (Electrically Erasable and Programmable Read Only Memory). The interface device F controls connection with the network.

  The input device G is, for example, a keyboard, a mouse, a button, a touch pad, a touch panel, a microphone, or the like. The display device H is a display device such as an LCD (Liquid Crystal Display) or a CRT (Cathode Ray Tube). In addition to the display device H, the server 40 may include other types of output devices such as a printer and a speaker.

[Function configuration]
FIG. 5 is a functional configuration example of the tag position estimation system 1 according to the first embodiment. In the tag position estimation system 1, for example, RFID readers 20 # 0 to 20 # 3 attached to a plurality of people transmit information to the server 40 via the wireless LAN access point 30. In FIG. 5 and the following description, it is assumed that RFID readers are attached to four people, but the number of people is merely an example. Further, in the following description, # and the following which are identifiers of the RFID reader 20 are omitted as necessary.

  Each RFID reader is provided with acceleration sensors 21 # 0 to 21 # 3 and communication devices 22 # 0 to 22 # 3 that can access the wireless LAN access point 30. Each acceleration sensor is, for example, a biaxial acceleration sensor, and detects and outputs a horizontal acceleration. Output values of the acceleration sensors 21 # 0 to 21 # 3 are transmitted to the server 40 together with ID information and the like as information associated with time. It should be noted that the output values of the acceleration sensors 21 # 0 to 21 # 3 may be corrected to eliminate the influence of gravity acceleration by the output of the gyro sensor or the like.

  The server 40 includes a time interval correction unit 42, an average time interval calculation unit 44, a relative position estimation unit 46, and an absolute function block that function by the CPU A executing a program stored in the auxiliary storage device D or the like. A position estimation unit 48. Input information 60 # 0 to 60 # 3, post-correction information 62 # 0 to 62 # 3, average time intervals 64 # 0 to 64 # 3, and the like illustrated in FIG. 5 are stored in the memory device E, for example.

  The time interval correction unit 42 corrects the input information 60 # 0 to 60 # 3 storing the ID information, detection time, and acceleration history received from each RFID reader 20 based on the moving speed of the RFID reader 20. To generate post-correction information 62 # 0-62 # 3. FIG. 6 is a diagram illustrating ID information and detection time collected when a certain person walks. The processing of the time interval correction unit 42 will be described later.

  The average time interval calculation unit 44 calculates the average time intervals 64 # 0 to 64 # 3 between the RFID tags 10 from the corrected information 62 # 0 to 62 # 3. For example, when a certain person moves between a specific RFID tag # 0001 and # 0002 three times in 10 seconds, 11 seconds, and 9 seconds, the average time interval calculation unit 44 determines the corresponding person between the two RFID tags. The average time interval is calculated as 10 seconds and stored in the memory device E. FIG. 7 is a diagram for explaining processing for calculating an average time interval from post-correction information.

[Relative position estimation]
The relative position estimation unit 46 estimates the relative position of each RFID tag 10 based on the average time interval 64 # 0 to 64 # 3 for each RFID reader. Hereinafter, the principle will be described.

  FIG. 8 is a diagram for explaining processing for estimating the relative positions of the RFID tags # 0001 to # 0003. As shown in the figure, the average time interval T (# 0001, # 0002) between the RFID tag # 0001 and the RFID tag # 0002, the average time interval T (# 0001, # 0003) between the RFID tag # 0001 and the RFID tag # 0003, the RFID When the average time interval T (# 0002, # 0003) between the tag # 0002 and the RFID tag # 0003 is obtained, the positional relationship between the three points is obtained.

  FIG. 9 is a diagram for explaining processing for estimating the relative positions of the RFID tags # 0001 to # 0004. Given the information obtained in FIG. 8, when the average time interval between RFID tags # 0001, # 0003, and # 0004 is obtained, the positional relationship of four points is obtained.

  As described above, the relative position of the RFID tag 10 by the RFID reader 20 attached to a certain person is obtained by spilling the positional relationship of the RFID tag 10. FIG. 10 is a diagram illustrating a state in which the relative position of the RFID tag 10 is obtained based on an average time interval obtained from a movement history of a certain person.

  When the relative position of the RFID tag 10 is obtained from the movement history of a certain person, a process of superimposing the relative position of the RFID tag 10 obtained from the movement history of another person is performed. FIG. 11 is a diagram for explaining processing for superimposing the relative positions of the RFID tags 10. Superposition can be performed if the relative positions share the same three points. Since the movement speed varies depending on the person, the scale of the obtained relative position differs depending on the person. For this reason, scale adjustment is necessary for superposition. Scale adjustment is performed by applying the ratio obtained by comparing the relative distances between the three shared points to the whole.

  FIG. 12 is a diagram for explaining a process of superimposing the relative position of the RFID tag 10 obtained from the movement history of another person.

[Absolute position estimation]
The absolute position estimation unit 48 obtains the absolute position of the RFID tag 10 from the relative position of the RFID tag 10 obtained by the above processing. The absolute position can be obtained, for example, by inputting measured values (absolute position coordinates) for the three RFID tags 10 whose relative positions have been obtained (excluding those arranged on a straight line). When absolute position coordinates are obtained for the three RFID tags 10, three affine transformation equations shown in equation (1) are obtained. In the formula, (x *, y *) indicates a position on the absolute position coordinate system, and (x, y) indicates a position on the relative position coordinate system (or vice versa). In this way, six simultaneous equations are obtained, and when the scale obtained from the distance between any two points is added, the parameters a ₁ , a ₂ , b ₁ , b ₂ , d _1, d ₂ of the affine transformation are Everything is required. When the absolute position estimation unit 48 obtains affine transformation parameters from the three relative position coordinates and the absolute position coordinates, the absolute position estimation unit 48 converts all relative position coordinates into absolute position coordinates using an affine transformation formula defined by the parameters. . FIG. 13 is a diagram schematically illustrating a state in which three points are selected from the relative position coordinates and an actual measurement value is input. FIG. 14 is a diagram schematically showing how the absolute position coordinates are obtained from the relative position coordinates.

[Correction by speed]
By the way, the moving speed of the RFID reader 20 is not always constant. In particular, when the RFID reader 20 is attached to the bottom surface of a person's footwear as described above, the moving speed varies not only depending on the walking speed but also depending on how the foot is carried.

  Therefore, the time interval correction unit 42 according to the present embodiment corrects the input information 60 # 0 to 60 # 3 based on the moving speed of the RFID reader 20, and the corrected information 62 # 0 to 62 # 3 is obtained. Generate. Specifically, the time interval correction unit 42 calculates the speed v (t) according to the time t of the RFID reader 20 based on the history of acceleration included in the input information 60 obtained from a certain person.

Next, the time interval correction unit 42 relates to all the RFID tags i, j, the integrated value L _{i, j represented} by the following equation (2), and the detection time interval t _{i, j} = (t _i −t _j ). And the maximum values Lmax and tmax obtained from the input information of the corresponding person are obtained. Then, the time interval correction unit 42 performs a calculation represented by the following equation (3) to obtain a normalized time interval t * _{i, j} after correction.

  FIG. 15 is a diagram schematically illustrating how the time interval correction unit 42 converts the time interval at which the RFID tag 20 is actually detected into a corrected time interval.

  By such processing, even when the moving speed of the RFID reader 20 varies as in the case where the RFID reader 20 is attached to the bottom surface of a person's footwear, the detection time interval of the RFID reader 20 can be corrected appropriately. As a result, the tag position estimation system 1 according to the first embodiment can estimate the tag position with high accuracy regardless of the movement mode of the RFID reader 20.

[flowchart]
Hereinafter, the flow of processing executed by the tag position estimation system 1 of the first embodiment will be described. FIG. 16 is an example of a flowchart showing a flow of processing executed by the tag position estimation system 1 of the first embodiment.

  First, the time interval correction unit 42 corrects the input information 60 based on the moving speed of the RFID reader 20 to generate post-correction information 62 (S100).

  Next, the average time interval calculation unit 44 calculates the average time interval 64 from the corrected information 62 (S102).

  Next, the relative position estimation unit 46 estimates the relative position of each RFID tag 10 for each RFID reader 20 from the average time interval 64, and synthesizes the relative positions for each of the plurality of RFID readers 20 to each RFID tag 10. Is estimated (S104).

  Next, the absolute position estimation unit 48 inputs the absolute position coordinates to at least three points of the relative position coordinates of each RFID tag 10 estimated by the relative position estimation unit 46, and estimates the absolute position of each RFID tag 10 ( S106).

[Summary]
In the tag position estimation system 1 according to the first embodiment of the present invention described above, since the time interval correction unit 42 corrects the input information 60 based on the moving speed of the RFID reader 20, the movement of the RFID reader 20 is performed. Regardless of the mode, the tag position can be estimated with high accuracy.

<Second embodiment>
Hereinafter, a tag position estimation system, a tag position estimation method, and a tag position estimation program according to a second embodiment of the present invention will be described with reference to the drawings.

  Since the hardware configuration is the same as that of the first embodiment, description thereof is omitted.

[Function configuration]
FIG. 17 is a functional configuration example of the tag position estimation system 2 according to the second embodiment. In the tag position estimation system 2, for example, RFID readers 20 # 0 to 20 # 3 attached to a plurality of people transmit information to the server 40 via the wireless LAN access point 30.

  Each RFID reader is provided with acceleration sensors 21 # 0 to 21 # 3 and communication devices 22 # 0 to 22 # 3 that can access the wireless LAN access point 30. Each acceleration sensor is, for example, a biaxial acceleration sensor, and detects and outputs a horizontal acceleration. Output values of the acceleration sensors 21 # 0 to 21 # 3 are transmitted to the server 40 together with ID information and the like as information associated with time.

  The server 40 according to the second embodiment includes a time information extraction unit 50, an average time interval calculation unit 44, a relative position as a functional block that functions when the CPU A executes a program stored in the auxiliary storage device D or the like. An estimation unit 46 and an absolute position estimation unit 48 are provided.

  The time information extraction unit 50 uses the input information 60 # 0 to 60 # 3 in which the ID information received from each RFID reader 20, the detection time, and the history of acceleration are stored in a period in which the moving speed of the RFID reader 20 is constant. The detected information is extracted to generate post-extraction information 66 # 0 to 66 # 3.

  By such processing, it is possible to perform processing by excluding information in a period in which the moving speed of the RFID reader 20 is not stable, such as when starting walking or stopping from walking. As a result, the tag position estimation system 2 of the second embodiment can estimate the tag position with high accuracy regardless of the movement mode of the RFID reader 20.

  The functions of the average time interval calculator 44, the relative position estimator 46, and the absolute position estimator 48 are the same as those in the first embodiment, and a description thereof will be omitted.

[flowchart]
Hereinafter, the flow of processing executed by the tag position estimation system 2 of the second embodiment will be described. FIG. 18 is an example of a flowchart showing a flow of processing executed by the tag position estimation system 2 of the second embodiment.

  First, the time information extraction unit 50 extracts information detected during a period when the moving speed of the RFID reader 20 is constant from the input information 60, and generates post-extraction information 66 (S200).

  Next, the average time interval calculation unit 44 calculates the average time interval 64 from the post-extraction information 66 (S202).

  Next, the relative position estimation unit 46 estimates the relative position of each RFID tag 10 for each RFID reader 20 from the average time interval 64, and synthesizes the relative positions for each of the plurality of RFID readers 20 to each RFID tag 10. Is estimated (S204).

  Next, the absolute position estimation unit 48 inputs the absolute position coordinates to at least three points of the relative position coordinates of each RFID tag 10 estimated by the relative position estimation unit 46, and estimates the absolute position of each RFID tag 10 ( S206).

[Summary]
In the tag position estimation system 2 according to the second embodiment of the present invention described above, the time interval correction unit 42 performs correction based on the moving speed of the RFID reader 20 with respect to the input information 60. Regardless of the mode, the tag position can be estimated with high accuracy.

<Third embodiment>
Hereinafter, a tag position estimation system, a tag position estimation method, and a tag position estimation program according to a third embodiment of the present invention will be described with reference to the drawings.

  Since the hardware configuration is the same as that of the first embodiment, description thereof is omitted.

[Function configuration]
FIG. 19 is a functional configuration example of the tag position estimation system 3 according to the third embodiment. In the tag position estimation system 3, for example, RFID readers 20 # 0 to 20 # 3 attached to a plurality of people transmit information to the server 40 via the wireless LAN access point 30.

  Each RFID reader is provided with communication devices 22 # 0 to 22 # 3 that can access the wireless LAN access point 30. In the present embodiment, the acceleration sensor is not an essential configuration.

  The RFID reader 20 according to the third embodiment does not transmit information on all detected RFID tags 10 to the server 40, but detects the RFID tag 10 only once in a certain period, for example, and detects the detected RFID tag 10. Information is transmitted to the server 40.

  As a result, the tag position estimation system 3 according to the third embodiment can suppress a decrease in accuracy due to fluctuations in the moving speed of the RFID reader 20. FIG. 20 is a diagram for explaining the effect of the tag position estimation system 3 according to the third embodiment. FIG. 20A shows a case where the RFID reader 20 transmits information related to all detected RFID tags 10 to the server 40, and FIG. 20B detects the RFID tag 10 only once in a certain period. Show the case. As shown in the figure, when information about all detected RFID tags 10 is transmitted to the server 40, if the moving speed of the RFID reader 20 varies due to walking or the like, the time interval at which the RFID tags 10 are detected can vary greatly. There is sex. On the other hand, in the tag position estimation system 3 according to the present embodiment, the time interval itself at which the RFID tag 10 is detected is relatively large, so that small fluctuations in the moving speed of the RFID reader 20 can be absorbed. As a result, the tag position estimation system 3 according to the third embodiment can suppress a decrease in accuracy due to fluctuations in the moving speed of the RFID reader 20.

  The server 40 according to the third embodiment includes an average time interval calculation unit 44, a relative position estimation unit 46, an absolute position as a functional block that functions when the CPU A executes a program stored in the auxiliary storage device D or the like. And an estimation unit 48. Since the functions of these functional blocks are the same as those in the first embodiment, description thereof will be omitted.

[flowchart]
Hereinafter, the flow of processing executed by the tag position estimation system 2 of the third embodiment will be described. FIG. 21 is an example of a flowchart showing a flow of processing executed by the tag position estimation system 3 of the third embodiment.

  First, the average time interval calculation unit 44 calculates an average time interval 64 from the input information 60 (S300).

  Next, the relative position estimation unit 46 estimates the relative position of each RFID tag 10 for each RFID reader 20 from the average time interval 64, and synthesizes the relative positions for each of the plurality of RFID readers 20 to each RFID tag 10. Is estimated (S302).

  Next, the absolute position estimation unit 48 inputs the absolute position coordinates to at least three points of the relative position coordinates of each RFID tag 10 estimated by the relative position estimation unit 46, and estimates the absolute position of each RFID tag 10 ( S304).

[Summary]
In the tag position estimation system 3 according to the third embodiment of the present invention described above, since the RFID reader 20 detects the RFID tag 10 only once in a certain period, regardless of the movement mode of the RFID reader 20, it is highly accurate. The position of the tag can be estimated.

  Note that the tag position estimation system 3 of the third embodiment performs a process of extracting detection times at regular intervals on the server 40 side, instead of the RFID reader 20 detecting the RFID tag 10 only once at regular intervals. May be.

  The best mode for carrying out the present invention has been described above with reference to the embodiments. However, the present invention is not limited to these embodiments, and various modifications can be made without departing from the scope of the present invention. And substitutions can be added.

  For example, the RFID reader 20, the acceleration sensor 21, and the communication device 22 may be attached not to the bottom surface of footwear but to the human trunk.

  Further, the RFID reader 20, the acceleration sensor 21, and the communication device 22 may be attached to a moving body other than a person.

  Moreover, although calculating the moving speed of the RFID reader | leader 20 by the output of the acceleration sensor 21 was illustrated, the server 40 may calculate | require a speed recursively based on the fluctuation | variation of detection time.

Regarding the above description, the following items are further disclosed.
(Appendix 1)
A tag ID reading unit that is attached to a mobile body and detects an ID tag installed within a communicable range, and that can read ID information held by the detected ID tag;
A storage unit in which the ID information read by the tag ID reading unit is stored in association with a detection time when the corresponding ID tag is detected;
A sensor unit for detecting a moving speed of the tag ID reading unit;
A relative position estimation unit that estimates the relative position of each tag based on the detection time interval stored in the storage unit and the output of the sensor unit;
A tag position estimation system comprising:
(Appendix 2)
The relative position estimation unit includes a correction unit that corrects an interval of detection times stored in the storage unit based on a moving speed of the tag ID reading unit obtained based on an output of the sensor unit, and the correction unit The tag position estimation system according to appendix 1, wherein the relative position of each tag is estimated using the corrected detection time interval.
(Appendix 3)
The correction unit is configured to detect the detection time stored in the storage unit based on a value obtained by integrating the moving speed of the tag ID reading unit obtained based on the output of the sensor unit at the detection time interval between the tags. Correct the interval,
The tag position estimation system according to attachment 2.
(Appendix 4)
The relative position estimation unit detects a tag ID detected in a period in which the speed of the tag ID obtained based on the output of the sensor unit is determined to be constant among the detection times stored in the storage unit. The tag position estimation system according to appendix 1, wherein the tag position estimation system includes an extraction unit that extracts time, and estimates a relative position of each tag based on an interval of detection times extracted by the extraction unit.
(Appendix 5)
A tag ID reading unit that is attached to a mobile body and detects an ID tag installed in a communicable range at a certain period, and that can read ID information held by the detected ID tag;
A storage unit that stores ID information read by the tag ID reading unit in association with a detection time at which the ID tag is detected;
A relative position estimation unit that estimates the relative position of each tag based on the detection time interval stored in the tag ID history storage unit;
A tag position estimation system comprising:
(Appendix 6)
An absolute position estimation unit that estimates the absolute position of each tag based on the relative position of each tag estimated by the relative position estimation unit and the input actual measurement value;
The tag position estimation system according to any one of appendices 1 to 5.
(Appendix 7)
A tag ID reading unit that is attached to a moving body and detects an ID tag installed in a communicable range, and that can read ID information held by the detected ID tag, and a moving speed of the tag ID reading unit. A computer connected to a sensor unit for detection
The ID information read by the tag ID reading unit is stored in the storage unit in association with the detection time when the corresponding ID tag is detected,
Based on the detection time interval stored in the storage unit and the output of the sensor unit, the relative position of each tag is estimated.
Tag position estimation method.
(Appendix 8)
A tag ID reading unit that is attached to a moving body and detects an ID tag installed in a communicable range, and that can read ID information held by the detected ID tag, and a moving speed of the tag ID reading unit. To the computer connected to the sensor unit for detection,
The ID information read by the tag ID reading unit is stored in the storage unit in association with the detection time when the corresponding ID tag is detected,
Based on the detection time interval stored in the storage unit and the output of the sensor unit, the relative position of each tag is estimated.
Tag position estimation program.

1, 2, 3 Tag position estimation system 10 RFID tag 20 RFID reader 30 Wireless LAN access point 40 Server 42 Time interval correction unit 44 Average time interval calculation unit 46 Relative position estimation unit 48 Absolute position estimation unit 50 Time information extraction unit A CPU
B drive device C storage medium D auxiliary storage device E memory device F interface device G input device H display device

Claims (6)

A tag ID reading unit that is attached to a mobile body and detects an ID tag installed within a communicable range, and that can read ID information held by the detected ID tag;
A storage unit in which the ID information read by the tag ID reading unit is stored in association with a detection time when the corresponding ID tag is detected;
A sensor unit for detecting a moving speed of the tag ID reading unit;
A correction unit that corrects the detection time interval stored in the storage unit based on the moving speed of the tag ID reading unit obtained based on the output of the sensor unit;
A relative position estimation unit that estimates the relative position of each tag using the detection time interval corrected by the correction unit;
An absolute position estimator that estimates the absolute position of each tag based on the relative position of each tag estimated by the relative position estimator and the measured values of the three input tags ;
A tag position estimation system comprising: The correction unit is configured to detect the detection time stored in the storage unit based on a value obtained by integrating the moving speed of the tag ID reading unit obtained based on the output of the sensor unit at the detection time interval between the tags. Correct the interval,
The tag position estimation system according to claim 1.   The relative position estimation unit detects a tag ID detected in a period in which the speed of the tag ID obtained based on the output of the sensor unit is determined to be constant among the detection times stored in the storage unit. The tag position estimation system according to claim 1, wherein time is extracted, and a relative position of each tag is estimated based on the extracted detection time interval. A tag ID reading unit that is attached to a mobile body and detects an ID tag installed in a communicable range at a certain period, and that can read ID information held by the detected ID tag;
A storage unit that stores ID information read by the tag ID reading unit in association with a detection time at which the ID tag is detected;
A relative position estimation unit that estimates the relative position of each tag based on the detection time interval stored in the tag ID history storage unit;
An absolute position estimator that estimates the absolute position of each tag based on the relative position of each tag estimated by the relative position estimator and the measured values of the three input tags ;
A tag position estimation system comprising: A tag ID reading unit that is attached to a moving body and detects an ID tag installed in a communicable range, and that can read ID information held by the detected ID tag, and a moving speed of the tag ID reading unit. A computer connected to a sensor unit for detection
The ID information read by the tag ID reading unit is stored in the storage unit in association with the detection time when the corresponding ID tag is detected,
Correcting the detection time interval stored in the storage unit based on the moving speed of the tag ID reading unit obtained based on the output of the sensor unit;
Estimate the relative position of each tag using the corrected detection time interval,
Estimating the absolute position of each tag based on the estimated relative position of each tag and the measured values of the three input tags.
Tag position estimation method. A tag ID reading unit that is attached to a moving body and detects an ID tag installed in a communicable range, and that can read ID information held by the detected ID tag, and a moving speed of the tag ID reading unit. To the computer connected to the sensor unit for detection,
The ID information read by the tag ID reading unit is stored in the storage unit in association with the detection time when the corresponding ID tag is detected,
The detection time interval stored in the storage unit is corrected based on the moving speed of the tag ID reading unit obtained based on the output of the sensor unit,
Using the corrected detection time interval, the relative position of each tag is estimated,
Based on the estimated relative position of each tag and the measured values of the three input tags, the absolute position of each tag is estimated.
Tag position estimation program.

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