Position correction device, position correction method, and position correction program

Abstract

A position correction device (100) is provided with a setting interval estimation unit (110) for correcting each estimated position when a plurality of wireless terminals are arranged in a two-dimensional lattice, the position of each wireless terminal is estimated as an estimated position, and each estimated position may include an error. A setting interval estimation unit (110) performs clustering on a plurality of wireless terminals such that the distance between two adjacent clusters satisfies a first setting interval condition on the basis of the coordinate components in the horizontal axis direction among the coordinate components of the respective estimated positions, and performs setting interval estimation on the plurality of wireless terminals on the basis of the coordinate components in the vertical axis direction among the coordinate components of the respective estimated positions. The plurality of wireless terminals are clustered such that the distance between two adjacent clusters satisfies a second setting interval condition.

Description

Technical Field

[0001] The present disclosure relates to a position correction device, a position correction method, and a position correction program. Background Art

[0002] There is a technology for correcting the estimated position of each wireless terminal when wireless terminals are arranged in a grid pattern and the position of each wireless terminal is estimated. Patent document 1 discloses a technology for correcting the estimated position of each wireless terminal at a grid point based on a building reference interval when wireless terminals are arranged in a grid pattern on a ceiling of a room or the like and the position of each wireless terminal is estimated.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2006-105662 Summary of the invention

[0006] Problem that the invention aims to solve

[0007] The installation interval of the wireless terminal is determined by the size of the room and the type of the wireless terminal. Therefore, the wireless terminals are not necessarily arranged based on the building reference interval. Therefore, in the technology disclosed in Patent Document 1, there is a problem that when the installation interval of the wireless terminal is unclear, the position of each wireless terminal estimated to be significantly different from the actual position of the wireless terminal may be corrected.

[0008] An object of the present disclosure is to correct the estimated position of each wireless terminal with relatively high accuracy when wireless terminals are arranged in a grid pattern and the position of each wireless terminal is estimated and the installation interval of the wireless terminals is unclear.

[0009] Means used to solve problems

[0010] The position correction device disclosed in the present invention corrects each estimated position when a first terminal group composed of a plurality of wireless terminals is configured in a two-dimensional grid shape, the position of each wireless terminal constituting the first terminal group is estimated as an estimated position, and each estimated position may contain an error, wherein the position correction device comprises a setting interval estimation unit, which performs clustering on the first terminal group in a manner that the distances between two adjacent clusters satisfy the first setting interval condition based on the coordinate components in the horizontal axis direction of the coordinate components of each estimated position, thereby estimating that each wireless terminal constituting the first terminal group is clustered. Configured on which grid line among the grid lines perpendicular to the horizontal axis direction, the horizontal axis direction is a direction estimated to be along one direction of the grid lines of the two-dimensional grid, the setting interval estimation unit performs clustering on the first terminal group based on the coordinate component of the vertical axis direction in the coordinate component of each estimated position in a manner that the distances between two adjacent clusters satisfy the second setting interval condition, thereby estimating on which grid line among the grid lines perpendicular to the vertical axis direction, the vertical axis direction is a direction estimated to be along another direction of the grid lines of the two-dimensional grid, each wireless terminal constituting the first terminal group is configured.

[0011] Effects of the Invention

[0012] According to the disclosure, the setting interval estimation unit estimates on which grid line each terminal is configured by performing clustering. Here, the setting interval of the wireless terminal can be estimated based on the distance between two adjacent clusters. Therefore, according to the disclosure, when the wireless terminals are configured in a grid shape, the positions of each wireless terminal are estimated, and the setting interval of the wireless terminals is unclear, the estimated positions of each wireless terminal can be corrected with relatively high accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 1 is a diagram showing a configuration example of the position correction device 100 according to the first embodiment.

[0014] Figure 2 This is a diagram for explaining the processing of the installation interval estimation unit 110 according to the first embodiment.

[0015] Figure 3 1 is a diagram showing a hardware configuration example of the position correction device 100 according to the first embodiment.

[0016] Figure 4 1 is a flowchart showing the operation of the installation interval estimation unit 110 according to the first embodiment.

[0017] Figure 5 1 is a diagram showing a hardware configuration example of a position correction device 100 according to a modification of the first embodiment. DETAILED DESCRIPTION

[0018] In the description of the embodiments and the accompanying drawings, the same reference numerals are used for the same elements and corresponding elements. The description of the elements marked with the same reference numerals is appropriately omitted or simplified. The arrows in the figures mainly show the flow of data or the process. In addition, the word "unit" can also be appropriately rewritten as "circuit", "process", "procedure", "processing" or "circuit".

[0019] Implementation method 1.

[0020] Hereinafter, this embodiment will be described in detail with reference to the drawings.

[0021] ***Structure description***

[0022] Figure 1 The following is a structural example of the position correction device 100 of the present embodiment. As shown in this figure, the position correction device 100 includes a setting interval estimation unit 110, a position correction unit 120, a terminal position storage unit 130, and a threshold storage unit 140. When a plurality of wireless terminals are arranged in a grid shape and the position of each wireless terminal is estimated, the position correction device 100 corrects the estimated position of each wireless terminal. The wireless terminal is a device having a wireless communication function, and as a specific example, it is an indoor unit of an air conditioner having a wireless communication function. Here, the wireless terminals are arranged in an array. The plurality of wireless terminals may also be arranged in a three-dimensional grid shape, but the following basically describes the case where the plurality of wireless terminals are arranged in a two-dimensional grid shape. When the plurality of wireless terminals are arranged in a two-dimensional grid shape, as a specific example, the plurality of wireless terminals are arranged in a grid shape on the ceiling of a certain floor. When the plurality of wireless terminals are arranged in a three-dimensional grid shape, as a specific example, the plurality of wireless terminals are arranged in a grid shape on the ceiling of each floor.

[0023] In the position correction device 100, when a first terminal group consisting of a plurality of wireless terminals is arranged in a two-dimensional grid, positions of each wireless terminal constituting the first terminal group are estimated as estimated positions, and each estimated position may contain an error, each estimated position is corrected.

[0024] The setting interval estimation unit 110 estimates the setting interval of the wireless terminal by applying a non-hierarchical clustering method to the terminal location information stored in the terminal location storage unit 130. That is, the setting interval estimation unit 110 estimates the setting interval of the wireless terminal by clustering a plurality of wireless terminals using a non-hierarchical clustering method. Here, the non-hierarchical clustering method is a method of unsupervised machine learning. As a specific example, the setting interval estimation unit 110 adopts a well-known technique such as a k-means method or a k-means++ method (a method of selecting initial values ​​by improving the k-means method) as a non-hierarchical clustering method. The setting interval estimation unit 110 may also determine the center position of each cluster in advance when performing clustering.

[0025] The setting interval estimation unit 110 performs clustering on the first terminal group in a manner that the distances between two adjacent clusters satisfy the first setting interval condition based on the coordinate components in the horizontal axis direction among the coordinate components of each estimated position, thereby estimating on which grid line of the grid lines perpendicular to the horizontal axis direction each wireless terminal constituting the first terminal group is configured. The horizontal axis direction is a direction estimated to be one direction along the grid lines of the two-dimensional grid. In addition, the setting interval estimation unit 110 performs clustering on the first terminal group in a manner that the distances between two adjacent clusters satisfy the second setting interval condition based on the coordinate components in the vertical axis direction among the coordinate components of each estimated position, thereby estimating on which grid line of the grid lines perpendicular to the vertical axis direction each wireless terminal constituting the first terminal group is configured. The vertical axis direction is a direction estimated to be another direction along the grid lines of the two-dimensional grid. The first setting interval condition may also respectively indicate the upper limit and lower limit of the distance between two adjacent clusters. The second setting interval condition may also respectively indicate the upper limit and lower limit of the distance between two adjacent clusters. The first setting interval condition and the second setting interval condition may also be the same.

[0026] The interval estimation unit 110 may use the average value of the distance between two adjacent clusters in the horizontal axis direction as the estimated value of the interval between adjacent grid lines in the horizontal axis direction, or may use the average value of the distance between two adjacent clusters in the vertical axis direction as the estimated value of the interval between adjacent grid lines in the vertical axis direction. The distance between two clusters may be defined in any manner.

[0027] Here, consider the case where multiple wireless terminals are configured in a three-dimensional grid. That is, consider the following case: the second terminal group composed of multiple wireless terminals is configured in a three-dimensional grid, and in the three-dimensional grid, the first terminal group is configured in each grid layer. The height axis direction is a direction perpendicular to the horizontal axis direction and perpendicular to the vertical axis direction. The grid layer is a layer perpendicular to the height axis direction and corresponding to the two-dimensional grid. In this case, the setting interval estimation unit 110 performs clustering on the second terminal group based on the coordinate components in the height axis direction of the coordinate components of each estimated position in a manner that the distances between two adjacent clusters satisfy the third setting interval condition, thereby estimating which grid layer each wireless terminal constituting the second terminal group is configured on. The third setting interval condition is the same as the first setting interval condition and the second setting interval condition.

[0028] Alternatively, when there are multiple results of clustering the first terminal group in such a manner that the distances between two adjacent clusters satisfy the first setting interval condition, the setting interval estimation unit 110 calculates, for each result, a score corresponding to the variance of the positions of the wireless terminals in each cluster shown by each result, and uses the result corresponding to the minimum score among the calculated scores as the result of clustering the first terminal group based on the coordinate component in the horizontal axis direction. Alternatively, when there are multiple results of clustering the first terminal group in such a manner that the distances between two adjacent clusters satisfy the second setting interval condition, the setting interval estimation unit 110 calculates, for each result, a score corresponding to the variance of the positions of the wireless terminals in each cluster shown by each result, and uses the result corresponding to the minimum score among the calculated scores as the result of clustering the first terminal group based on the coordinate component in the vertical axis direction.

[0029] The position correction unit 120 corrects the estimated terminal position on the grid point near the terminal position based on the setting interval estimated by the setting interval estimation unit 110. In addition, the position correction unit 120 updates the terminal position information stored in the terminal position storage unit 130 based on the corrected terminal position. The terminal position is the position of the wireless terminal. The terminal position information is information indicating the terminal position. The terminal position shown in the terminal position information can represent the estimated terminal position, or can represent the terminal position after the estimated terminal position is corrected. As a specific example, the estimated terminal position is a terminal position estimated based on information such as radio wave intensity, radio wave arrival angle, and radio wave arrival time, or a terminal position manually measured using a laser distance meter or a tape measure. The terminal position can also be expressed in any of two dimensions and three dimensions. In addition, it is assumed that the terminal position before correction contains an error. The error contained in the terminal position before correction is a degree that does not cause the clustering performed by the setting interval estimation unit 110 to fail.

[0030] Figure 2 This is a diagram that uses a specific example to explain the process of the position correction unit 120 correcting the estimated position of each wireless terminal when 9 wireless terminals are arranged in a two-dimensional grid. Here, the terminal position before correction is the terminal position estimated based on observation results, etc. The reference position is a position selected to determine the position of a virtual two-dimensional grid in which multiple wireless terminals are arranged. In this example, the reference position is the position of the wireless terminal located at the lower left. As a specific example, the reference position is an estimated arbitrary terminal position. The variable x corresponds to the horizontal axis direction, and the variable y corresponds to the vertical axis direction. C xi represents the i-th cluster in the horizontal direction, C yi represents the i-th cluster in the vertical direction. i，j Δy represents the distance between the center of the i-th cluster in the horizontal direction and the center of the j-th cluster in the horizontal direction.i，j represents the distance between the center of the i-th cluster in the vertical direction and the center of the j-th cluster in the vertical direction. i and j are variables corresponding to natural numbers. Δx^ represents the setting interval in the horizontal direction, and Δy^ represents the setting interval in the vertical direction. Δ1 represents the lower limit of the setting interval, Δ2 represents the upper limit of the setting interval, and N cx Indicates the number of clusters in the horizontal direction, N cy Indicates the number of clusters in the vertical direction. In addition, Δx indicates the setting interval in the horizontal direction, and Δy indicates the setting interval in the vertical direction. Δx is synonymous with the interval of the grid points in the horizontal direction. Δy is synonymous with the interval of the grid points in the vertical direction. In addition, in the main text of the specification, the symbols are expressed in a form that can be expressed in the main text. Therefore, the expression of the symbols in the figure and the expression of the symbols in the main text are sometimes different.

[0031] use Figure 2 The processing of the installation interval estimation unit 110 will be described.

[0032] First, the setting interval estimation unit 110 performs clustering using the coordinate components in the horizontal axis direction of the coordinate components of the terminal position by a non-hierarchical clustering method, thereby creating three clusters. xi The wireless terminal is estimated to be configured with C xi on the corresponding grid lines.

[0033] Next, the installation interval estimation unit 110 calculates the installation interval in the horizontal axis direction based on the distance between clusters adjacent to each other in the horizontal axis direction.

[0034] Next, the setting interval estimation unit 110 determines whether the calculated setting interval satisfies the setting interval condition. In addition, when the calculated setting interval does not satisfy the setting interval condition, the setting interval estimation unit 110 changes the number of clusters and performs clustering using the coordinate components in the horizontal axis direction again. The setting interval condition is a condition related to the setting interval of the wireless terminal, and as a specific example, it is a condition indicating the upper limit and lower limit of the setting interval. The setting interval condition can also be determined based on the setting interval of a normal wireless terminal. As a specific example, when the wireless terminal is an air conditioner, the setting interval condition is a condition indicating 3m as the lower limit and 7m as the upper limit.

[0035] Next, the setting interval estimation unit 110 performs clustering using the coordinate components in the vertical axis direction of the coordinate components of the terminal position by a non-hierarchical clustering method, thereby creating three clusters. yi The wireless terminal is estimated to be configured with C yi on the corresponding grid lines.

[0036] Next, the installation interval estimation unit 110 calculates the installation interval in the vertical axis direction based on the distance between clusters adjacent to each other in the vertical axis direction.

[0037] Next, the installation interval estimation unit 110 determines whether the calculated installation interval satisfies the installation interval condition. If the calculated installation interval does not satisfy the installation interval condition, the installation interval estimation unit 110 changes the number of clusters and performs clustering again using the coordinate components in the vertical axis direction.

[0038] Through the above processing, a virtual two-dimensional grid in which a plurality of wireless terminals are arranged is estimated. In the estimated virtual two-dimensional grid, the interval between grid lines in the horizontal axis direction is Δx, and the interval between grid lines in the vertical axis direction is Δy.

[0039] The terminal position storage unit 130 stores and manages each terminal position information. In the terminal position storage unit 130, the terminal positions corresponding to the plurality of wireless terminals are managed.

[0040] The threshold storage unit 140 stores and manages the threshold used by the installation interval estimation unit 110. As a specific example, the threshold includes the lower limit and the upper limit of the installation interval in each direction of the horizontal axis direction and the vertical axis direction. The installation interval in the horizontal axis direction may be the same as the installation interval in the vertical axis direction.

[0041] Figure 3 The following is a hardware configuration example of the position correction device 100 according to the present embodiment. The position correction device 100 is configured by a computer. The position correction device 100 may be configured by a plurality of computers.

[0042] As shown in the figure, the position correction device 100 is a computer including hardware such as a processor 11, a memory 12, an auxiliary storage device 13, an input / output interface (Interface) 14, and a communication device 15. These hardware are connected via a signal line 19 as appropriate.

[0043] The processor 11 is an IC (Integrated Circuit) that performs calculations and controls hardware included in the computer. As a specific example, the processor 11 is a CPU (Central Processing Unit), a DSP (Digital Signal Processor), or a GPU (Graphics Processing Unit).

[0044] The position correction device 100 may include a plurality of processors instead of the processor 11. The plurality of processors share the role of the processor 11.

[0045] The memory 12 is typically a volatile storage device, and a specific example is a RAM (Random Access Memory). The memory 12 is also called a main storage device or a main memory. The data stored in the memory 12 is stored in the auxiliary storage device 13 as needed.

[0046] The auxiliary storage device 13 is typically a nonvolatile storage device, and specific examples thereof include ROM (Read Only Memory), HDD (Hard Disk Drive), or flash memory. Data stored in the auxiliary storage device 13 is loaded into the memory 12 as needed.

[0047] The memory 12 and the auxiliary storage device 13 may be integrally configured.

[0048] The input / output interface 14 is a port for connecting an input device and an output device. As a specific example, the input / output interface 14 is a USB (Universal Serial Bus) terminal. As a specific example, the input device is a keyboard and a mouse. As a specific example, the output device is a display.

[0049] The communication device 15 is a receiver and a transmitter. As a specific example, the communication device 15 is a communication chip or a NIC (Network Interface Card).

[0050] When each unit of the position correction device 100 communicates with other devices, the input / output interface 14 and the communication device 15 may be used as appropriate.

[0051] The auxiliary storage device 13 stores a position correction program. The position correction program is a program that causes a computer to implement the functions of each unit of the position correction device 100. The position correction program is loaded into the memory 12 and executed by the processor 11. The functions of each unit of the position correction device 100 are implemented by software.

[0052] The data used when executing the position correction program and the data obtained by executing the position correction program are appropriately stored in the storage device. Each part of the position correction device 100 appropriately uses the storage device. As a specific example, the storage device is composed of at least one of the memory 12, the auxiliary storage device 13, the register in the processor 11, and the cache memory in the processor 11. In addition, the term "data" and the term "information" may have the same meaning. The storage device may also be a device independent of the computer.

[0053] The functions of the memory 12 and the auxiliary storage device 13 may also be implemented by other storage devices.

[0054] The position correction program may also be recorded in a computer-readable nonvolatile recording medium. As a specific example, the nonvolatile recording medium is an optical disk or a flash memory. The position correction program may also be provided as a program product.

[0055] ***Action description***

[0056] The operation process of the position correction device 100 corresponds to the position correction method. In addition, the program for realizing the operation of the position correction device 100 corresponds to the position correction program.

[0057] Figure 4 2 is a flowchart showing an example of the processing of the setting interval estimation unit 110. Figure 4 The processing of the installation interval estimation unit 110 will be described. Here, N represents the total number of wireless terminals arranged in a grid. In this example, the installation interval condition represents a lower limit Δ1 of the installation interval and an upper limit Δ2 of the installation interval.

[0058] (Step S101)

[0059] The installation interval estimation unit 110 selects a reference terminal from a plurality of wireless terminals. The reference terminal is a wireless terminal corresponding to a reference position and is a wireless terminal used to estimate the position of a virtual grid in a space where a plurality of wireless terminals are arranged. In addition, the direction of the grid lines of the virtual grid may also be determined according to the structure of the space, such as along the wall.

[0060] (Step S102)

[0061] The installation interval estimation unit 110 calculates the difference between the x-coordinate of the reference position and the x-coordinate of the terminal position corresponding to each wireless terminal as the difference data of the x-coordinate corresponding to each wireless terminal other than the reference terminal. The x-coordinate is a coordinate component in the horizontal axis direction. In addition, the difference data of the x-coordinate corresponding to the reference terminal represents 0.

[0062] (Step S103)

[0063] The installation interval estimation unit 110 calculates the difference between the y coordinate of the reference position and the y coordinate of the terminal position corresponding to each wireless terminal as the difference data of the y coordinate corresponding to each wireless terminal other than the reference terminal. The y coordinate is a coordinate component in the vertical axis direction. In addition, the difference data of the y coordinate corresponding to the reference terminal represents 0.

[0064] (Step S104)

[0065] The setting interval estimation unit 110 substitutes 1 into Ncx.

[0066] (Step S105)

[0067] The setting interval estimation unit 110 substitutes 0 into Δx^.

[0068] (Step S106)

[0069] The setting interval estimation unit 110 substitutes N / Ncx into Ncy.

[0070] (Step S107)

[0071] When the value of Ncy is 1, the setting interval estimation unit 110 proceeds to step S108. Otherwise, the setting interval estimation unit 110 proceeds to step S109.

[0072] (Step S108)

[0073] The setting interval estimation unit 110 substitutes 0 into Δy^.

[0074] (Step S109)

[0075] The setting interval estimation unit 110 clusters the one-dimensional data obtained by adding 0 to the differential data of N-1 y coordinates, using the number of clusters Ncy. That is, the setting interval estimation unit 110 generates a one-dimensional array consisting of the value indicated by the differential data of the y coordinate and 0 for the differential data of each y coordinate, and performs clustering using the generated one-dimensional array, thereby generating Ncy clusters.

[0076] In this step, the installation interval estimation unit 110 performs clustering on the first terminal group based on the coordinate component in the vertical axis direction.

[0077] (Step S110)

[0078] The interval estimation unit 110 calculates the distances between the centers of adjacent clusters among the generated Ncy clusters, and sets the average value of the calculated distances to Δy^.

[0079] (Step S111)

[0080] If Δy^ satisfies the setting interval condition, the setting interval estimation unit 110 proceeds to step S112. Otherwise, the setting interval estimation unit 110 proceeds to step S113.

[0081] (Step S112)

[0082] The setting interval estimation unit 110 calculates a score corresponding to the variance of the position of the wireless terminal in each cluster generated in at least one of step S109 and step S115. Specifically, the setting interval estimation unit 110 calculates the sum of squares of the intra-cluster errors corresponding to the generated clusters as the score. Here, as a specific example, the setting interval estimation unit 110 calculates the sum of squares of the intra-cluster errors using Euclidean distance, Mahalanobis distance, or Manhattan distance. The score is not limited to a value based on the sum of squares of the errors, but may also be a value based on the absolute value of the errors. In addition, the setting interval estimation unit 110 may also calculate the score corresponding to the cluster generated in step S109 and the score corresponding to the cluster generated in step S115, respectively.

[0083] (Step S113)

[0084] The installation interval estimation unit 110 sets the value of Ncx to the smallest natural number that satisfies mod(N, Ncx)=0 and is larger than the current Ncx.

[0085] (Step S114)

[0086] When the value of Ncx is equal to or smaller than N, the installation interval estimation unit 110 proceeds to step S115. Otherwise, the installation interval estimation unit 110 proceeds to step S118.

[0087] (Step S115)

[0088] The setting interval estimation unit 110 clusters one-dimensional data obtained by adding 0 to the differential data of N-1 x-coordinates, using the number of clusters Ncx. That is, the setting interval estimation unit 110 generates a one-dimensional array consisting of the value indicated by the differential data of the x-coordinate and 0 for the differential data of each x-coordinate, and performs clustering using the generated one-dimensional array, thereby generating Ncx clusters.

[0089] In this step, the installation interval estimation unit 110 performs clustering on the first terminal group based on the coordinate components in the horizontal axis direction.

[0090] (Step S116)

[0091] The setting interval estimation unit 110 calculates the distances between the centers of adjacent clusters among the generated Ncx clusters, and sets the average value of the calculated distances to Δx^.

[0092] (Step S117)

[0093] When the value of Δx^ satisfies the setting interval condition, the setting interval estimation section 110 proceeds to step S106. Otherwise, the setting interval estimation section 110 proceeds to step S113.

[0094] (Step S118)

[0095] The setting interval estimation unit 110 outputs Ncx, Ncy, Δx ^, and Δy ^ corresponding to the minimum score among the scores calculated in step S112. That is, when there are multiple results of clustering based on the coordinate components of the object direction in a manner that satisfies the prescribed setting interval condition, the setting interval estimation unit 110 selects an appropriate result based on the value of the score calculated in step S112.

[0096] **Description of the effects of Embodiment 1**

[0097] As described above, according to the present embodiment, when the installation interval of the wireless terminal is unclear, the installation interval estimation unit 110 estimates the virtual grid where the wireless terminal is arranged by performing clustering. In addition, the position correction unit 120 corrects the position of the wireless terminal to the grid point of the virtual grid estimated by the installation interval estimation unit 110. Therefore, according to the present embodiment, the position of the wireless terminal can be corrected with relatively high accuracy.

[0098] ***Other structures***

[0099] <Variation 1>

[0100] Figure 5 A hardware configuration example of the position correction device 100 according to this modification is shown.

[0101] The position correction device 100 includes a processing circuit 18 instead of the processor 11 , the processor 11 and the memory 12 , the processor 11 and the auxiliary storage device 13 , or the processor 11 , the memory 12 , and the auxiliary storage device 13 .

[0102] The processing circuit 18 is hardware that realizes at least a part of each unit included in the position correction device 100 .

[0103] The processing circuit 18 may be dedicated hardware, or may be a processor that executes a program stored in the memory 12 .

[0104] When the processing circuit 18 is dedicated hardware, as a specific example, the processing circuit 18 is a single circuit, a complex circuit, a programmed processor, a parallel programmed processor, an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or a combination thereof.

[0105] The position correction device 100 may include a plurality of processing circuits instead of the processing circuit 18. The plurality of processing circuits share the role of the processing circuit 18.

[0106] In position correction device 100 , part of the functions may be implemented by dedicated hardware, and the remaining functions may be implemented by software or firmware.

[0107] As a specific example, the processing circuit 18 is implemented by hardware, software, firmware, or a combination thereof.

[0108] The processor 11, the memory 12, the auxiliary storage device 13, and the processing circuit 18 are collectively referred to as a “processing circuit.” That is, the functions of the functional components of the position correction device 100 are implemented by the processing circuit.

[0109] ***Other implementation methods***

[0110] Implementation 1 has been described, but multiple parts in this implementation may be implemented in combination. Alternatively, this implementation may be implemented partially. In addition, this implementation may be modified in various ways as needed, and may be implemented in combination in whole or in part in any manner.

[0111] The above-described embodiments are merely preferred examples in nature and are not intended to limit the scope of the present disclosure, its application targets, and its uses. The processes described using flowcharts and the like may be modified as appropriate.

[0112] Description of Reference Numerals

[0113] 11 processor, 12 memory, 13 auxiliary storage device, 14 input / output interface, 15 communication device, 18 processing circuit, 19 signal line, 100 position correction device, 110 setting interval estimation unit, 120 position correction unit, 130 terminal position storage unit, 140 threshold storage unit.

Claims

1. A position correction device, which corrects each estimated position when a first terminal group consisting of a plurality of wireless terminals is arranged in a two-dimensional grid, the positions of each wireless terminal constituting the first terminal group are estimated as estimated positions, and each estimated position may contain an error, wherein: The position correction device includes a setting interval estimation unit, The setting interval estimation unit clusters the first terminal group in a manner such that distances between two adjacent clusters satisfy a first setting interval condition based on the coordinate components in the horizontal axis direction of the coordinate components of each estimated position, thereby estimating on which grid line of grid lines perpendicular to the horizontal axis direction each wireless terminal constituting the first terminal group is configured, wherein the horizontal axis direction is estimated to be a direction along the grid lines of the two-dimensional grid, The setting interval estimation unit clusters the first terminal group based on the coordinate component in the vertical axis direction among the coordinate components of each estimated position in such a way that the distances between two adjacent clusters satisfy the second setting interval condition, thereby estimating on which grid line of the grid lines perpendicular to the vertical axis direction each wireless terminal constituting the first terminal group is configured, wherein the vertical axis direction is estimated to be another direction along the grid lines of the two-dimensional grid.

2. The position correction device according to claim 1, wherein: The first setting interval condition indicates the upper limit and lower limit of the distance between two adjacent clusters, respectively. The second installation interval condition indicates the upper limit and the lower limit of the distance between two adjacent clusters.

3. The position correction device according to claim 1 or 2, wherein: The setting interval estimation section performs clustering on the plurality of wireless terminals using a non-hierarchical type clustering method.

4. The position correction device according to any one of claims 1 to 3, wherein: The setting interval estimation unit uses the average value of the distance between two adjacent clusters in the horizontal axis direction as the estimated value of the interval between adjacent grid lines in the horizontal axis direction, and uses the average value of the distance between two adjacent clusters in the vertical axis direction as the estimated value of the interval between adjacent grid lines in the vertical axis direction.

5. The position correction device according to any one of claims 1 to 4, wherein: In a case where there are multiple results of clustering the first terminal group in a manner in which the distances between two adjacent clusters all satisfy the first setting interval condition, the setting interval estimation unit calculates, for each result, a score corresponding to the variance of the positions of the wireless terminals in each cluster indicated by each result, and uses the result corresponding to the minimum score among the calculated scores as the result of clustering the first terminal group based on the coordinate component in the horizontal axis direction. When there are multiple results of clustering the first terminal group in a manner in which the distances between two adjacent clusters satisfy the second setting interval condition, the setting interval estimation unit calculates, for each result, a score corresponding to the variance of the positions of the wireless terminals within each cluster shown by each result, and uses the result corresponding to the minimum score among the calculated scores as the result of clustering the first terminal group based on the coordinate component in the vertical axis direction.

6. The position correction device according to any one of claims 1 to 5, wherein: When the second terminal group consisting of a plurality of wireless terminals is arranged in a three-dimensional grid, and the first terminal group is arranged in each grid layer which is a layer perpendicular to the height axis direction and corresponding to the two-dimensional grid in the three-dimensional grid, The setting interval estimation unit clusters the second terminal group based on the coordinate component in the height axis direction among the coordinate components of each estimated position in such a way that the distances between two adjacent clusters satisfy the third setting interval condition, thereby estimating on which grid layer each wireless terminal constituting the second terminal group is configured, wherein the height axis direction is a direction perpendicular to the horizontal axis direction and to the vertical axis direction.

7. A method for correcting a position, wherein, when a first terminal group consisting of a plurality of wireless terminals is arranged in a two-dimensional grid, the positions of the wireless terminals constituting the first terminal group are estimated as estimated positions, and each estimated position may contain an error, the method corrects each estimated position, wherein: The computer performs the following processing: Based on the coordinate components in the horizontal axis direction of the coordinate components of each estimated position, clustering is performed on the first terminal group in such a manner that distances between two adjacent clusters satisfy a first setting interval condition, thereby estimating on which grid line of grid lines perpendicular to the horizontal axis direction each wireless terminal constituting the first terminal group is configured, wherein the horizontal axis direction is estimated to be a direction along the grid lines of the two-dimensional grid, Based on the coordinate component in the vertical axis direction among the coordinate components of each estimated position, clustering is performed on the first terminal group in such a way that the distances between two adjacent clusters satisfy the second setting interval condition, thereby estimating on which grid line of the grid lines perpendicular to the vertical axis direction each wireless terminal constituting the first terminal group is configured, wherein the vertical axis direction is estimated to be another direction along the grid lines of the two-dimensional grid.

8. A position correction program executed by a position correction device as a computer, wherein, when a first terminal group consisting of a plurality of wireless terminals is arranged in a two-dimensional grid, the positions of the wireless terminals constituting the first terminal group are estimated as estimated positions, and each estimated position may contain an error, the position correction device corrects each estimated position, wherein: The position correction program causes the position correction device to perform the following setting interval estimation process: Based on the coordinate components in the horizontal axis direction of the coordinate components of each estimated position, clustering is performed on the first terminal group in such a manner that distances between two adjacent clusters satisfy a first setting interval condition, thereby estimating on which grid line of grid lines perpendicular to the horizontal axis direction each wireless terminal constituting the first terminal group is configured, wherein the horizontal axis direction is estimated to be a direction along the grid lines of the two-dimensional grid, Based on the coordinate component in the vertical axis direction among the coordinate components of each estimated position, clustering is performed on the first terminal group in such a way that the distances between two adjacent clusters satisfy the second setting interval condition, thereby estimating on which grid line of the grid lines perpendicular to the vertical axis direction each wireless terminal constituting the first terminal group is configured, wherein the vertical axis direction is estimated to be another direction along the grid lines of the two-dimensional grid.

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