JP7613160B2 - Positioning system, server, communication device, and communication terminal - Google Patents

Description

This disclosure relates to a positioning system, a server, a communication device, and a communication terminal.

Patent Document 1 discloses a position detection system that detects the position of an object by wireless communication. The position detection system disclosed in Patent Document 1 wirelessly communicates between multiple fixed communication devices and a mobile communication device, selects three or more fixed communication devices, and calculates the position of the mobile communication device based on the positions of the selected three or more fixed communication devices and the radio wave strength at the reception points of three or more reference signals wirelessly communicated between the selected three or more fixed communication devices and the mobile communication device.

International Publication No. 2020/021737

Indoors, such as in a factory, the radio wave strength may be weak depending on the shape of the room and obstacles, and there may be places where positioning is impossible. However, even if the position detection system disclosed in Patent Document 1 is used, the user cannot determine which places are positionable and which are not.

A positioning system according to one aspect of the present disclosure includes a communication terminal attached to an object placed in a target area, a plurality of communication devices that measure the distance to the object by wirelessly communicating with the communication terminal, and a server that receives distance measurement information indicating the distance measurement results from each of the plurality of communication devices. The server includes a positioning unit that measures the position of the object based on the distance measurement information received from three or more communication devices, a memory unit that stores positioning information indicating the measurement results by the positioning unit, a first estimation unit that estimates a positionable area based on the positioning information stored in the memory unit, and an output unit that outputs information regarding the positionable area estimated by the first estimation unit.

A server according to one aspect of the present disclosure includes a receiver that receives distance measurement information indicating distance measurement results from each of a plurality of communication devices that measure distances to objects by wirelessly communicating with a communication terminal attached to an object placed in a target area, a positioning unit that measures the position of the object based on the distance measurement information received by the receiver from three or more communication devices, a storage unit that stores positioning information indicating the measurement results by the positioning unit, a first estimation unit that estimates a positionable area based on the positioning information stored in the storage unit, and an output unit that outputs information related to the positionable area estimated by the first estimation unit.

A communication device according to one aspect of the present disclosure includes a first communication unit that wirelessly communicates with a communication terminal attached to an object placed in a target area, a distance measurement unit that measures the distance to the object by wirelessly communicating with the communication terminal via the first communication unit, and a second communication unit that communicates with a server, and the second communication unit transmits distance measurement information indicating the results of distance measurement by the distance measurement unit to the server so that the server measures the position of the object, estimates a positionable area based on positioning information indicating the measurement results, and outputs information related to the estimated positionable area.

A communication terminal according to one aspect of the present disclosure is a communication terminal that is attached to an object placed in a target area, and includes a wireless communication unit that wirelessly communicates with the communication device so that the communication device measures the distance to the object, and a display unit that displays that positioning is possible based on the number of communication devices that have wirelessly communicated with the wireless communication unit.

The present disclosure can be realized not only as a positioning system having the above-mentioned characteristic configuration, but also as a method in which characteristic processing in a positioning system is a step, or as a server, communication device, or communication terminal included in a positioning system and having a characteristic configuration. Furthermore, the present disclosure can be realized as a computer program that causes a computer to function as a server, communication device, or communication terminal, or as a semiconductor integrated circuit as part or all of the server, communication device, or communication terminal.

This disclosure makes it possible to provide information about locations where positioning is possible.

FIG. 1 is a diagram illustrating an example of a configuration of a positioning system according to an embodiment. 1 is a block diagram showing an example of a configuration of a communication device according to an embodiment. FIG. 2 is a block diagram showing an example of a configuration of a communication terminal according to the embodiment. FIG. 2 is a block diagram showing an example of a configuration of a server according to the embodiment. FIG. 2 is a functional block diagram illustrating an example of functions of a communication device according to an embodiment. FIG. 2 is a functional block diagram illustrating an example of functions of the communication terminal according to the embodiment. FIG. 2 is a functional block diagram illustrating an example of functions of a server according to the embodiment. FIG. 11 is a diagram illustrating an example of a distance measurement information table. FIG. 11 is a diagram illustrating an example of a positioning information table. FIG. 4 is a sequence diagram showing an example of an operation of the positioning system according to the embodiment. 10 is a flowchart illustrating a procedure of a determination process performed by the communication terminal according to the embodiment. 10 is a flowchart illustrating a procedure of a positioning process performed by a server according to the embodiment. 10 is a flowchart showing a procedure of a positioning available area map creation process performed by a server according to the embodiment. 10 is a flowchart showing a procedure of a process for creating a distance measurable area map by a server according to the embodiment. FIG. 4 is a diagram showing an example of a display of a positioning available area map according to the embodiment. 11A and 11B are diagrams illustrating an example of a display of a measurable area map according to the embodiment.

Overview of the embodiments of the present disclosure
Below, an overview of the embodiments of the present disclosure will be listed and described.

(1) The positioning system according to this embodiment includes a communication terminal attached to an object placed in a target area, a plurality of communication devices that measure the distance to the object by wirelessly communicating with the communication terminal, and a server that receives distance measurement information indicating the distance measurement results from each of the plurality of communication devices, and the server includes a positioning unit that measures the position of the object based on the distance measurement information received from three or more communication devices, a memory unit that stores positioning information indicating the measurement results by the positioning unit, a first estimation unit that estimates a positionable area based on the positioning information stored in the memory unit, and an output unit that outputs information regarding the positionable area estimated by the first estimation unit. This makes it possible to provide information regarding the positionable area in the target area to a user.

(2) The information regarding the positionable area may be a positionable area map in which the positionable area is superimposed on a map of the target area. This makes it possible to provide a user with information that allows the positionable area to be visually recognized.

(3) The server may further include a second estimation unit that compares the positionable area with a set positioning area in the target area and estimates a positioning impossible area within the set positioning area where positioning by the positioning unit is impossible, and the output unit may output information regarding the positioning impossible area. This makes it possible to provide the user with information regarding the positioning impossible area within the target area in addition to information regarding the positioning possible area.

(4) The storage unit stores the ranging information received from each of the plurality of communication devices, and the server further includes a third estimation unit that estimates, for each communication device, a ranging area in which the communication device can measure distances based on the ranging information stored in the storage unit, and the output unit may output information related to the ranging area estimated by the third estimation unit. This makes it possible to provide the user with information related to areas in the target area in which ranging can be performed by each communication device, in addition to information related to the positioning area.

(5) The third estimation unit may estimate the measurable area for each communication device further based on the position of an object whose distance is measured by the communication device. This makes it possible to estimate the measurable area with higher accuracy.

(6) The third estimation unit may estimate the measurable area for each communication device further based on the position of an object whose distance was not measured by the communication device. This allows the measurable area to be estimated with higher accuracy.

(7) The server may further include a third estimation unit that estimates, for each communication device, a measurable area in which the communication device can measure distance based on the position of an object whose distance is measured by the communication device, and the output unit may output information about the measurable area estimated by the third estimation unit. This makes it possible to generate information about the area in which the communication device can measure distance based on the position of an object whose distance is measured by the communication device.

(8) The server may further include a third estimation unit that estimates, for each communication device, a measurable area in which the communication device can measure distances based on the position of an object whose distance has not been measured by the communication device, and the output unit may output information about the measurable area estimated by the third estimation unit. This makes it possible to generate information about the area in which the communication device can measure distances based on the position of an object whose distance has not been measured by the communication device.

(9) The information regarding the measurable area may be a measurable area map in which the measurable area is superimposed on a map of the target area. This makes it possible to provide a user with information that allows the measurable area to be visually recognized.

(10) The server may further include a fourth estimation unit that compares the measurable area with a set measurable area in the target area and estimates an unmeasurable area within the set measurable area where the communication device cannot measure distances. This makes it possible to identify areas where the communication device cannot measure distances.

(11) The communication device measures the distance to the object by wirelessly communicating with the communication terminal using a first radio wave and transmits first distance measurement information, and measures the distance to the object using a second radio wave different from the first radio wave and transmits second distance measurement information, the positioning unit measures the position of the object based on the first distance measurement information received from three or more communication devices and outputs first positioning information, and measures the position of the object based on the second distance measurement information and outputs second positioning information, the storage unit stores the first positioning information and the second positioning information, the first estimation unit estimates a first positioning available area based on the first positioning information and estimates a second positioning available area based on the second positioning information, and the output unit may output a first map indicating the first positioning available area and a second map indicating the second positioning available area. This makes it possible to provide the user with the first map and the second map obtained by the two types of radio waves, respectively.

(12) When the ranging information for one object is received from two communication devices, the positioning unit may determine the position of the object based on the ranging information and an area in which the presence of the object is estimated, and generate information indicating the determined position as the positioning information. In this way, even if ranging is not possible with three communication devices, it is possible to determine the position of an object whose ranging can be measured by two communication devices.

(13) The server may further include a determination unit that determines the reliability of the positioning information based on the number of communication devices from which the distance measurement information for each object has been obtained. This makes it possible to identify highly reliable positioning information.

(14) The communication terminal may include a display unit that displays whether positioning is possible based on the number of communication devices that have performed wireless communication. This allows the user to recognize whether or not the object is a positionable object based on the display on the display unit.

(15) The communication device may transmit distance measurement reliability information indicating the reliability of the distance measurement information to the server, and the storage unit may store the distance measurement reliability information received from the communication device. This makes it possible to obtain information indicating the reliability of each piece of distance measurement information.

(16) The server according to this embodiment includes a receiving unit that receives distance measurement information indicating distance measurement results from each of a plurality of communication devices that measure distances to objects by wirelessly communicating with a communication terminal attached to an object placed in a target area, a positioning unit that measures the position of the object based on the distance measurement information received by the receiving unit from three or more communication devices, a storage unit that stores positioning information indicating the measurement results by the positioning unit, a first estimation unit that estimates a positionable area based on the positioning information stored in the storage unit, and an output unit that outputs information regarding the positionable area estimated by the first estimation unit. This makes it possible to provide information regarding the positionable area in the target area to a user.

(17) The communication device according to this embodiment includes a first communication unit that wirelessly communicates with a communication terminal attached to an object placed in a target area, a distance measurement unit that measures the distance to the object by wirelessly communicating with the communication terminal via the first communication unit, and a second communication unit that communicates with a server, and the second communication unit transmits distance measurement information indicating the results of distance measurement by the distance measurement unit to the server so that the server can measure the position of the object, estimate a positionable area based on positioning information indicating the measurement results, and output information related to the estimated positionable area. This enables the server to generate information related to the positionable area in the target area and provide the information to a user.

(18) The communication terminal according to this embodiment is a communication terminal that is attached to an object placed in a target area, and includes a wireless communication unit that wirelessly communicates with the communication devices so that the communication devices can measure the distance to the object, and a display unit that displays that positioning is possible based on the number of communication devices that have wirelessly communicated with the wireless communication unit. This allows the user to recognize whether or not the object is positionable based on the display on the display unit.

<Details of the embodiment of the present disclosure>
Hereinafter, the details of the embodiments of the present invention will be described with reference to the drawings. Note that at least some of the embodiments described below may be combined in any desired manner.

[1. Positioning System]
1 is a diagram showing an example of the configuration of a positioning system according to the present embodiment. A positioning system 10 according to the present embodiment measures the positions of objects 30_A, 30_B, 30_C, 30_D, 30_E, 30_F, 30_G, 30_H, and 30_I arranged in a target area 20 indoors, such as a factory. In this embodiment, the target area 20 is set to "AAA Factory First Area."

The positioning system 10 includes communication terminals 100_A, 100_B, 100_C, 100_D, 100_E, 100_F, 100_G, 100_H, and 100_I, communication devices 200_A, 200_B, 200_C, 200_D, 200_E, 200_F, 200_G, 200_H, 200_I, 200_J, 200_K, and 200_L, and a server 300. In the following description, objects 30_A, 30_B, 30_C, 30_D, 30_E, 30_F, 30_G, 30_H, and 30_I are collectively referred to as "objects 30." Communication terminals 100_A, 100_B, 100_C, 100_D, 100_E, 100_F, 100_G, 100_H, and 100_I are also collectively referred to as "communication terminals 100." Communication devices 200_A, 200_B, 200_C, 200_D, 200_E, 200_F, 200_G, 200_H, 200_I, 200_J, 200_K, and 200_L are also collectively referred to as "communication devices 200."

The object 30 may be, for example, a finished product or semi-finished product manufactured in a factory, materials or tools used in manufacturing the product, or a transport device used to transport the finished product or semi-finished product.

One communication terminal 100 is attached to one object 30. The communication terminal 100 is used to measure the distance to the object. The communication terminal 100 is capable of wireless communication.

The communication device 200 is fixed at a specified position in the target area 20. The communication device 200 is capable of wireless communication. The communication device 200 is, for example, a relay device that relays communication. In this embodiment, the communication device 200 is a wireless access point. The communication device 200 is capable of measuring the distance to the object 30 (communication terminal 100) by wireless communication with the communication terminal 100.

The communication device 200 is connected to the server 300 by wire or wirelessly. The server 300 can measure the position of the object 30 based on the distance measurement results by the communication device 200. The server 300 can estimate the positionable area in the target area 20 based on the position measurement results of the object 30. Furthermore, the server 300 can estimate the measurable area for each communication device based on the distance measurement results by each communication device 200. The server 300 can output a measurable area map as information regarding the measurable area. The server 300 can output a measurable area map as information regarding the measurable area.

2. Configuration of Positioning System
[2-1. Configuration of communication device]
2 is a block diagram showing an example of the configuration of a communication device according to the present embodiment. The communication device 200 includes a processor 201, a non-volatile memory 202, a volatile memory 203, a first communication interface (I/F) 204, and a second communication I/F 205.

The volatile memory 203 is, for example, a semiconductor memory such as a static random access memory (SRAM) or a dynamic random access memory (DRAM). The non-volatile memory 202 is, for example, a flash memory, a hard disk, a read only memory (ROM), etc. The non-volatile memory 202 stores a distance measurement program 206, which is a computer program, and data used to execute the distance measurement program 206. The communication device 200 is configured with a computer, and each function of the communication device 200 is realized by the processor 201 executing the distance measurement program 206, which is a computer program stored in the storage device of the computer. The distance measurement program 206 is a computer program that allows the communication device 200 to wirelessly communicate with the communication terminal 100 and measure the distance to the communication terminal 100.

The processor 201 is, for example, a CPU (Central Processing Unit). However, the processor 201 is not limited to a CPU. The processor 201 may be a GPU (Graphics Processing Unit). The processor 201 is configured to be able to execute a computer program. The processor 201 may be, for example, an ASIC (Application Specific Integrated Circuit) or a programmable logic device such as a gate array or an FPGA (Field Programmable Gate Array). In this case, the ASIC or programmable logic device is configured to be able to execute processing similar to that of the ranging program 206.

The first communication I/F 204 is an interface for wireless communication. The first communication interface 204 has an antenna 204A and can transmit and receive wireless signals via the antenna 204A. The communication device 200 can wirelessly communicate with the communication terminal 100 via the first communication I/F 204. The first communication I/F 204 can perform wireless communication, for example, via UWB (Ultra Wide Band). The first communication I/F 204 may also be able to perform wireless communication via a wireless communication method other than UWB, such as 5G (fifth generation mobile communication system) or Bluetooth (registered trademark).

The second communication I/F 205 is a wired communication interface or a wireless communication interface. The second communication I/F 205 is, for example, an Ethernet interface ("Ethernet" is a registered trademark). The communication device 200 can communicate with the server 300 via the second communication I/F 205.

[2-2. Configuration of communication terminal]
3 is a block diagram showing an example of the configuration of a communication terminal according to this embodiment. The communication terminal 100 includes a processor 101, a non-volatile memory 102, a volatile memory 103, a communication I/F 104, and LEDs 105A and 105B.

The volatile memory 103 is, for example, a semiconductor memory such as an SRAM or a DRAM. The non-volatile memory 102 is, for example, a flash memory, a hard disk, a ROM, etc. The non-volatile memory 102 stores a determination program 106, which is a computer program, and data used to execute the determination program 106. The communication terminal 100 is configured with a computer, and each function of the communication terminal 100 is realized by the processor 101 executing the determination program 106, which is a computer program stored in the storage device of the computer. The determination program 106 is a computer program for determining whether or not the communication terminal 100 is capable of being positioned.

The processor 101 is, for example, a CPU. However, the processor 101 is not limited to a CPU. The processor 101 may be a GPU. The processor 101 is configured to be able to execute a computer program. The processor 101 may be, for example, an ASIC, or a programmable logic device such as a gate array or FPGA. In this case, the ASIC or programmable logic device is configured to be able to execute processing similar to that of the determination program 106.

The communication I/F 104 is an interface for wireless communication. The communication interface 104 has an antenna 104A and can transmit and receive wireless signals via the antenna 104A. The communication terminal 100 can wirelessly communicate with the communication device 200 via the communication I/F 104. The communication I/F 104 can perform wireless communication via UWB, for example. The communication I/F 104 may also be capable of performing wireless communication via a wireless communication method other than UWB, such as 5G or Bluetooth.

LED 105A is used to indicate that communication terminal 100 can be positioned. LED 105B is used to indicate that communication terminal 100 cannot be positioned. LED 105A and LED 105B emit light in different colors. For example, LED 105A emits light in green and LED 105B emits light in red.

[2-3. Server configuration]
4 is a block diagram showing an example of the configuration of a server according to this embodiment. The server 300 includes a processor 301, a non-volatile memory 302, a volatile memory 303, an input device 304, a display device 305, and a communication I/F 306.

Volatile memory 303 is, for example, a semiconductor memory such as an SRAM or a DRAM. Non-volatile memory 302 is, for example, a flash memory, a hard disk, a ROM, etc. Non-volatile memory 302 stores an estimation program 307, which is a computer program, and data used to execute the estimation program 307. Server 300 is configured with a computer, and each function of server 300 is exercised by processor 301 executing estimation program 307, which is a computer program stored in the storage device of the computer. Estimation program 307 is a computer program that server 300 uses to estimate the positioning area of positioning system 10.

The processor 301 is, for example, a CPU. However, the processor 301 is not limited to a CPU. The processor 301 may be a GPU. The processor 301 is configured to be able to execute a computer program. The processor 301 may be, for example, an ASIC, or a programmable logic device such as a gate array or FPGA. In this case, the ASIC or programmable logic device is configured to be able to execute processing similar to that of the estimation program 307.

The input device 304 includes, for example, a keyboard and a pointing device such as a mouse. The display device 305 includes, for example, a liquid crystal panel or an OEL (organic electroluminescence) panel. The input device 304 is used to input information to the server 300. The display device 305 can display text or graphic information on the screen.

The communication I/F 306 is a wired communication interface or a wireless communication interface. The communication I/F 306 is, for example, an Ethernet interface. The server 300 can communicate with the communication device 200 via the communication I/F 306.

[3. Functions of the Positioning System]
Fig. 5 is a functional block diagram showing an example of the functions of the communication device according to the present embodiment. Fig. 6 is a functional block diagram showing an example of the functions of the communication terminal according to the present embodiment.

The communication device 200 has the functions of a wireless communication unit 210, a communication time measurement unit 220, a distance measurement unit 230, and a transmission unit 240. The communication terminal 100 has the functions of a wireless communication unit 110, a processing time measurement unit 120, a determination unit 130, and a display unit 140.

Refer to FIG. 5. The wireless communication unit 210 can transmit a ranging signal wirelessly. The ranging signal is a wireless signal used to measure the distance from the communication device 200 to the communication terminal 100.

Refer to FIG. 6. The wireless communication unit 110 can receive a ranging signal transmitted from the communication device 200. When the wireless communication unit 110 receives the ranging signal, it can return the ranging signal.

The processing time measurement unit 120 measures the time from when the wireless communication unit 110 receives the ranging signal to when it transmits the ranging signal. In other words, the processing time measurement unit 120 can measure the processing time from when it receives the ranging signal to when it returns it. For example, the ranging signal transmitted from the wireless communication unit 110 includes processing time information indicating the processing time measured by the processing time measurement unit 120. The processing time information may be transmitted from the wireless communication unit 110 separately from the ranging signal.

Referring again to FIG. 5. The wireless communication unit 210 can receive a ranging signal transmitted from the communication terminal 100. The communication time measurement unit 220 measures the communication time from when the wireless communication unit 210 transmits a ranging signal to the communication terminal 100 to when it receives the ranging signal from the communication terminal 100.

The distance measurement unit 230 measures the distance from the communication device 200 to the communication terminal 100 based on the communication time measured by the communication time measurement unit 220. Specifically, the distance measurement unit 230 calculates the difference between the communication time measured by the communication time measurement unit 220 and the processing time notified by the communication terminal 100. This difference corresponds to the sum of the time it takes for the ranging signal to be emitted from the communication device 200 to reach the communication terminal 100 and the time it takes for the ranging signal to be emitted from the communication terminal 100 to reach the communication device 200, that is, the round trip time for the ranging signal to be transmitted. The distance measurement unit 230 calculates the distance from the communication device 200 to the communication terminal 100 by multiplying the value obtained by dividing the calculated difference by 2 by a coefficient.

The transmission unit 240 transmits distance measurement information indicating the distance measurement results by the distance measurement unit 230 to the server 300.

Referring again to FIG. 6. The determination unit 130 determines whether or not the communication terminal 100 can be positioned. As described below, when one communication terminal 100 is distanced by three or more communication devices 200, the communication terminal 100 is positioned. Therefore, when the determination unit 130 receives distance measurement signals from three or more communication devices 200 within a predetermined period, it determines that the communication terminal 100 can be positioned. When the determination unit 130 does not receive distance measurement signals from three or more communication devices 200 within a predetermined period, it determines that the communication terminal 100 cannot be positioned.

The display unit 140 displays that positioning is possible based on the number of communication devices 200 that have performed wireless communication. When the determination unit 130 determines that positioning is possible, the display unit 140 displays that positioning is possible. When the determination unit 130 determines that positioning is impossible, the display unit 140 may display that positioning is impossible. The display unit 140 includes, for example, LED 105A and LED 105B. When the determination unit 130 determines that positioning is possible, LED 105A may be lit, and when the determination unit 130 determines that positioning is impossible, LED 105B may be lit.

Figure 7 is a functional block diagram showing an example of the functions of the server according to this embodiment. The server 300 includes a receiving unit 310, a memory unit 320, a positioning unit 330, a determination unit 340, a first estimation unit 350, a second estimation unit 360, a third estimation unit 370, a fourth estimation unit 380, and an output unit 390.

The receiving unit 310 can receive distance measurement information transmitted from the communication device 200.

The memory unit 320 stores the distance measurement information received by the receiver unit 310. The memory unit 320 includes, for example, a non-volatile memory 302. The memory unit 320 stores distance measurement information indicating the distance measurement results by each communication device 200 during a predetermined period.

In a specific example, the memory unit 320 includes a ranging information table for storing ranging information for a specified period, and stores the ranging information acquired from each communication device 200 for the specified period in the ranging information table. FIG. 8 is a diagram showing an example of a ranging information table. In the example shown in FIG. 8, the ranging information table M1 stores ranging results for each object 30 (communication terminal 100) and each communication device 200. For example, for object 30_A, the ranging result of communication device 200_A is "4.2", the ranging result of communication device 200_B is "10.8", the ranging result of communication device 200_D is "5.5", the ranging result of communication device 200_E is "2.9", and the ranging result of communication device 200_G is "12.3". For object 30_B, the distance measurement result of communication device 200_B is "4.8", and the distance measurement result of communication device 200_F is "5.2". If distance measurement is not possible, the distance measurement result is set to Null (indicated by "-" in FIG. 8).

The memory unit 320 accumulates ranging information obtained in the past. For example, ranging information obtained during a specified period is stored in the ranging information table M1 as described above, and after the specified period has elapsed, a new period begins. The ranging information obtained during the new period is stored in the new ranging information table M1. In this way, the ranging information table M1 is added to the memory unit 320 every specified period, and the past ranging information tables M1 are accumulated.

The positioning unit 330 measures the position of the object 30 based on the distance measurement information received from three or more communication devices 200. For example, the positions (coordinates) of each communication device 200 are stored in the non-volatile memory 302. The positioning unit 330 identifies the position of the object 30 using the positions of each communication device 200 from which the distance measurement information was obtained and the distance measurement information obtained by each communication device 200.

Positioning information indicating the measured position of object 30 is stored in memory unit 320. In a specific example, memory unit 320 includes a positioning information table for storing positioning information for a specified period, and stores the positioning information of each object 30 for the specified period in the positioning information table. Figure 9 is a diagram showing an example of a positioning information table. In the example shown in Figure 9, positioning information table M2 stores positioning results for each object 30 (communication terminal 100). For example, the positioning result of object 30_A is "3, 3, 1". Here, the positioning result indicates coordinate values (x, y, z). There is no positioning result for object 30_B. In other words, object 30_B cannot be positioned. The positioning result of object 30_C is "7, 9, 2", the positioning result of object 30_D is "7, 1, 1", the positioning result of object 30_E is "8, 1, 1", the positioning result of object 30_F is "9, 4, 2", the positioning result of object 30_G is "10, 8, 1", and the positioning result of object 30_H is "10, 9, 2". There is no positioning result for object 30_I, and object 30_I cannot be positioned. If positioning is not possible, the positioning result is set to Null (indicated by "-" in FIG. 9).

Refer back to FIG. 7. The determination unit 340 determines the reliability of the positioning information based on the number of communication devices from which distance measurement information was obtained for each object 30. The storage unit 320 stores the reliability of the positioning information. In the example of FIG. 9, the reliability of each positioning result is stored in the positioning information table M2. For example, the reliability of the positioning result of the object 30_A is "5", the reliability of the positioning result of the object 30_C is "4", the reliability of the positioning result of the object 30_D is "5", the reliability of the positioning result of the object 30_E is "4", the reliability of the positioning result of the object 30_F is "4", the reliability of the positioning result of the object 30_G is "5", and the reliability of the positioning result of the object 30_H is "3".

The reliability of the positioning result is determined based on the number of ranging results used for positioning. In the example shown in FIG. 9, the reliability is the number of ranging results. For example, the positioning result of object 30_A is calculated based on five ranging results of communication devices 200_A, 200_B, 200_D, 200_E, and 200_G. Therefore, the reliability of this positioning result is "5". The positioning result of object 30_C is calculated based on four ranging results of communication devices 200_B, 200_F, 200_G, and 200_H. Therefore, the reliability of this positioning result is "4".

For example, the reliability of the positioning result may be determined based on the reliability of the ranging result used for positioning. The positioning information table M2 shown in FIG. 9 stores the reliability of the ranging result for each communication device 200 and each object 30. For example, the reliability of the ranging result of object 30_A by communication device 200_A is "9.5", the reliability of the ranging result of object 30_A by communication device 200_B is "5.2", the reliability of the ranging result of object 30_A by communication device 200_D is "6.5", the reliability of the ranging result of object 30_A by communication device 200_E is "10", and the reliability of the ranging result of object 30_A by communication device 200_G is "4.1". The reliability of the distance measurement result of object 30_B by communication device 200_B is "9.6", and the reliability of the distance measurement result of object 30_B by communication device 200_F is "4.0". The reliability of the distance measurement result may be determined based on the reception level of the distance measurement signal in communication device 200, or may be determined based on the reception level of the distance measurement signal in communication terminal 100. Communication device 200 transmits distance measurement information including the distance measurement result and the reliability of the distance measurement result to server 300, and server 300 stores the distance measurement result in distance measurement information table M1 and stores the reliability in positioning information table M2.

The storage unit 320 accumulates positioning information obtained in the past. For example, positioning information obtained during a specified period is stored in the positioning information table M2 as described above, and after the specified period has elapsed, a new period begins. Positioning information obtained during the new period is stored in the new positioning information table M2. In this way, the positioning information table M2 is added to the storage unit 320 every specified period, and past positioning information tables M2 are accumulated.

Refer to FIG. 7 again. The first estimation unit 350 estimates the positionable area based on the positioning information stored in the storage unit 320. Specifically, the first estimation unit 350 estimates the positionable area based on past positioning information accumulated in the storage unit 320. For example, it can be estimated that the measured position of the object 30 is a positionable position, and that the area around the position is a positionable area. Therefore, the first estimation unit 350 can determine the union of areas of a predetermined radius from the past measured positions of the object 30 as the positionable area. For example, the first estimation unit 350 may discard the positioning result if the reliability of the positioning result is equal to or lower than a predetermined reference value. This makes it possible to eliminate positioning results with low reliability.

The second estimation unit 360 compares the positioning possible area estimated by the first estimation unit 350 with the set positioning area in the target area 20. The set positioning area is an area in the target area 20 where positioning is required. The set positioning area is, for example, an area in the target area 20 defined by a user. The user can input the set positioning area to the server 300 using the input device 304. For example, the set positioning area may be a past positioning possible area. The second estimation unit 360 estimates a positioning impossible area, which is an area in the set positioning area where positioning by the positioning unit 330 is impossible. The second estimation unit 360 can determine an area of the set positioning area that does not overlap with the positioning possible area as a positioning impossible area.

The third estimation unit 370 estimates a measurable area, which is an area where the communication device 200 can measure distance, for each communication device 200 based on the distance measurement information stored in the memory unit 320. The third estimation unit 370 can focus on one communication device 200 and estimate the measurable area of the communication device 200 based on the distance measurement result obtained from the communication device 200. Specifically, the third estimation unit 370 can set the measurable area to a circle centered on the position of the focused communication device 200 and with a radius equal to the maximum distance indicated by the distance measurement result. The third estimation unit 370 may estimate the measurable area for each communication device 200 based further on the positioning information stored in the memory unit 320. For example, the third estimation unit 370 identifies an object 30 that can be located based on the positioning information, and if the identified object 30 matches an object 30 for which a focused communication device 200 has previously measured distances, it can estimate the measurable area of the communication device 200 based on the position of the object 30. In a specific example, an area of a predetermined width from the position of the focused communication device 200 to the position of the measured object 30 can be set as a measurable partial area, and the union of such partial areas can be set as the measurable area.

The third estimation unit 370 can estimate the measurable area for each communication device 200 based further on the object 30 for which the distance was not measured by the communication device 200. For example, the third estimation unit 370 can correct the measurable area by deleting the area outside (in the direction away from the focused communication device 200) the position of the object 30 for which the communication device 200 was unable to measure the distance from the measurable area of the focused communication device 200 estimated based on the distance measurement information as described above.

The fourth estimation unit 380 compares the measurable area estimated by the third estimation unit 370 with the set measurable area in the target area 20. The set measurable area is an area in the target area 20 where measurment is required. The set measurable area is, for example, an area in the target area 20 defined by the user. The user can input the set measurable area to the server 300 using the input device 304. For example, the set measurable area may be a past measurable area. For example, the set measurable area may be the same area as the set positioning area. The fourth estimation unit 380 estimates a measurable area within the set measurable area, which is an area where measurment by the communication device 200 is not possible. The measurable area is estimated for each communication device 200. The fourth estimation unit 380 can determine an area of the set measurable area that does not overlap with the measurable area as the measurable area.

The output unit 390 outputs information related to the positionable area estimated by the first estimation unit 350. The output unit 390 can output a positionable area map as information related to the positionable area. The positionable area map is an image in which the positionable area is superimposed on a map of the target area 20.

The output unit 390 may output information about the non-positionable area estimated by the second estimation unit 360. For example, an image in which the non-positionable area is superimposed on a map of the target area 20 may be used as information about the non-positionable area. In a specific example, the output unit 390 outputs a positionable area map in which the positionable area and the non-positionable area are each superimposed on a map of the target area 20.

The output unit 390 may output information relating to the measurable area estimated by the third estimation unit 370. The output unit 390 can output a measurable area map as information relating to the measurable area. The measurable area map is an image in which the measurable area is superimposed on a map of the target area 20. The measurable area map is generated for each communication device 200.

The output unit 390 may output information about the non-measurable area estimated by the fourth estimation unit 380. For example, an image in which the non-measurable area is superimposed on a map of the target area 20 may be used as information about the non-measurable area. In a specific example, the output unit 390 outputs a measurable area map in which the measurable area and the non-measurable area are each superimposed on a map of the target area 20.

4. Operation of the Positioning System
[4-1. Overall operation of the positioning system]
FIG. 10 is a sequence diagram showing an example of the operation of the positioning system according to the present embodiment.

The processor 201 of the communication device 200 transmits a ranging signal to the communication terminal 100 (step S1). The processor 201 starts measuring the communication time at the same time as transmitting the ranging signal. The processor 101 of the communication terminal 100 starts measuring the processing time at the same time as receiving the ranging signal (step S2). The processor 101 returns the ranging signal to the communication device 200 (step S3). The measured processing time is incorporated into the ranging signal or is transmitted to the communication device 200 separately from the ranging signal.

When the processor 201 receives the ranging signal, it ends the measurement of the communication time (step S4). The processor 201 executes the ranging process. In the ranging process, the distance between the communication device 200 and the object 30 (communication terminal 100) is calculated as described above. The processor 201 transmits ranging information including the ranging result to the server 300 (step S6).

The server 300 receives the distance measurement information transmitted from each communication device 200. The distance measurement results are stored in the distance measurement information table M1. When three or more communication devices 200 measure the distance of one object 30, the object 30 can be positioned based on the distance measurement information. The processor 301 of the server 300 executes a positioning process and calculates the position of the object 30 based on the distance measurement information of the one object 30 obtained by the three or more communication devices 200 (step S7). The positioning results are stored in the positioning information table M2.

The processor 301 estimates the positioning possible area based on the accumulated positioning results (step S8). The processor 301 further compares the estimated positioning possible area with the set positioning area to estimate the positioning impossible area (step S9).

The processor 301 focuses on one communication device 200 and estimates the measurable area based on the past distance measurement results of that communication device (step S10). The processor 301 then changes the communication device being focused on and estimates the measurable area for each of the communication devices 200. The processor 301 then focuses on one communication device 200 and compares the estimated measurable area with the set measurable area to estimate the non-measurable area (step S11). The processor 301 then changes the communication device being focused on and estimates the non-measurable area for each of the communication devices 200.

The processor 301 outputs the estimation result (step S12). That is, the processor 301 outputs a positionable area map in which the positionable area and the non-positionable area are each superimposed on the map of the target area 20, and outputs a positionable area map in which the measurable area and the non-measurable area are each superimposed on the map of the target area 20.

[4-2. Communication terminal determination process]
Next, a description will be given of a process for determining whether or not positioning is possible by the communication terminal 100. Fig. 11 is a flowchart showing the procedure of the determination process by the communication terminal according to this embodiment.

The processor 101 of the communication terminal 100 determines whether or not ranging signals have been received from three or more communication devices 200 within a predetermined period of time (step S101).

As described above, when one object 30 is measured by three or more communication devices 200, the object 30 can be located. Therefore, when the processor 101 receives measuring signals from three or more communication devices 200 in a predetermined period (YES in step S101), the processor 101 determines that the object 30 to which the communication terminal 100 is attached can be located, and turns on the LED 105A to indicate that the object 30 to which the communication terminal 100 is attached can be located (step S102). When the processor 101 does not receive measuring signals from three or more communication devices 200 in a predetermined period (NO in step S101), the processor 101 determines that the object 30 to which the communication terminal 100 is attached cannot be located, and turns on the LED 105B to indicate that the object 30 to which the communication terminal 100 is attached cannot be located (step S103). This ends the determination process.

[4-3. Server positioning process]
Next, a detailed description will be given of the positioning process by the server 300. Fig. 12 is a flowchart showing the procedure of the positioning process by the server according to this embodiment.

The processor 301 selects one communication terminal 100, i.e., an object 30 (step S201). For example, each communication terminal 100 is managed by an ID. In step S201, the ID of the communication terminal 100 is selected.

The processor 301 reads the ranging information of the selected communication terminal 100 from the latest ranging information table M1 (step S202). The processor 301 determines whether the number of communication devices 200 that are the senders of the read ranging information is three or more (step S203).

If the number of communication devices 200 that have sent the distance measurement information is less than three (NO in step S203), the processor 301 ends the process because positioning of the object 30 is not possible.

If the number of communication devices 200 that have sent the distance measurement information is three or more (YES in step S203), the processor 301 calculates (measures) the position of the object based on the read distance measurement information (step S204). The processor 301 writes the calculated position information, i.e., the positioning result, to the positioning information table M2 (step S205). This completes the positioning process.

The processor 301 selects and executes the above-described positioning process for all communication terminals 100, i.e., objects 30. This allows the positioning of all objects 30 that can be positioned to be performed.

[4-4. Positioning area map creation process]
Next, details of the estimation of the positioning available area, the estimation of the non-positioning area, and the creation of the positioning available area map (hereinafter, referred to as the "positioning available area map creation process") by the server 300 will be described. Fig. 13 is a flowchart showing the procedure of the positioning available area map creation process by the server according to this embodiment.

The processor 301 reads out the accumulated positioning results from the positioning information table M2 (step S301). The processor 301 estimates the positioning possible area based on the read out positioning results (step S302). For example, the processor 301 determines the positioning possible area to be the union of areas of a predetermined radius from the past measurement positions of the object 30.

The processor 301 compares the estimated positioning possible area with the set positioning area and estimates the non-positioning possible area (step S303). For example, the processor 301 determines the area of the set positioning area that does not overlap with the positioning possible area as the non-positioning possible area.

The processor 301 creates a positionable area map by superimposing the positionable area and the non-positionable area on the map of the target area 20 (step S304). In the positionable area map, the positionable area and the non-positionable area are distinguishable.

The processor 301 displays the created positioning area map on the display device 305 (step S305). This completes the positioning area map creation process.

[4-5. Processing for creating a map of distance measurement area]
Next, the details of the estimation of the measurable area and the non-measurable area and the creation of the measurable area map (hereinafter, referred to as the "measurable area map creation process") by the server 300 will be described. Fig. 14 is a flowchart showing the procedure of the measurable area map creation process by the server according to this embodiment.

The processor 301 selects one communication device 200 (step S401). For example, each communication device 200 is managed by an ID. In step S401, the ID of the communication device 200 is selected.

The processor 301 reads out from the ranging information table M1 the ranging results transmitted from the communication device 200 selected in step S401 among the accumulated ranging results (step S402). The processor 301 identifies the object 30 whose distance and position have been measured by the selected communication device 200 (step S403). In Figures 8 and 9, for example, the object 30_A has been measured by the communication device 200_A and its position has been measured. Therefore, when the communication device 200_A is selected, the object 30_A is identified as the object 30 whose distance and position have been measured by the selected communication device 200. Furthermore, the processor 301 identifies the object 30 whose distance and position cannot be measured by the selected communication device 200 (step S404). 8 and 9, for example, objects 30_C, 30_D, 30_E, 30_F, 30_G, and 30_H have not been measured by communication device 200_A and have been positioned. Therefore, when communication device 200_A is selected, objects 30_C, 30_D, 30_E, 30_F, 30_G, and 30_H are identified as objects 30 whose distances cannot be measured by the selected communication device 200 and whose positions have been measured.

Refer to FIG. 14 again. The processor 301 estimates the measurable area based on the read distance measurement result (step S405). For example, the processor 301 sets the measurable area to a circle with the position of the selected communication device 200 as the center and the maximum distance indicated by the distance measurement result as the radius. Furthermore, the processor 301 sets the area of a predetermined width from the position of the selected communication device 200 to the position of the object 30 measured by the communication device 200 and located by the communication device 200 as a measurable partial area, and corrects the measurable area by adding this partial area to the measurable area estimated based on the distance measurement information as described above. Furthermore, the processor 301 corrects the measurable area by deleting the area outside the position of the object 30 that could not be measured by the selected communication device 200 (in the direction away from the selected communication device 200) from the measurable area estimated as described above.

The processor 301 compares the estimated measurable area with the set measurable area and estimates the non-measurable area (step S406). For example, the processor 301 determines an area of the set measurable area that does not overlap with the measurable area as the non-measurable area.

The processor 301 creates a measurable area map by superimposing the measurable area and the non-measurable area on the map of the target area 20 (step S407). In the measurable area map, the measurable area and the non-measurable area are distinguishable.

The processor 301 then causes the display device 305 to display the created measurable area map (step S408). This completes the measurable area map creation process.

[4-6. Map display]
Next, the display of the positioning available area map and the distance measuring available area map will be described. Fig. 15 is a diagram showing an example of the display of the positioning available area map according to this embodiment, and Fig. 16 is a diagram showing an example of the display of the distance measuring available area map according to this embodiment.

As shown in Figs. 15 and 16, the positioning area map and the distance measurement area map are displayed within the positioning system screen. The positioning system screen includes a map display section 400, an area selection button 421, a positioning area display button 422, an AP selection button 423, and a distance measurement area display button 424.

Refer to FIG. 15. When displaying a positioning area map, the user specifies the target area 20 using the area selection button 421. For example, when the user selects the area selection button 421 using the input device 304, a list containing items of areas that are candidates for display is displayed. The user uses the input device 304 to select the item of the target area 20 from the list. In this state, it becomes possible to display the positioning area map 410 or the distance measurement area map 430 of the target area 20 on the map display unit 400.

The user selects the positionable area display button 422 using the input device 304. This causes a positionable area map 410 of the target area 20 to be displayed on the map display unit 400. The positionable area map 410 is a map in which a positionable area 411 and a non-positionable area 413 are superimposed on a map of the target area 20. The area surrounded by a thick line in the figure is the set positioning area 412 that has been set by the user.

The positionable area 411 is included in the set positioning area 412. The non-positionable area 413 is an area in the set positioning area 412 other than the positionable area 411. The positionable area 411 and the non-positionable area 413 are displayed, for example, in different colors. This allows the user to easily distinguish between the positionable area 411 and the non-positionable area 413. The positionable area 411 allows the user to confirm the area in which the object 30 can be positioned, and the non-positionable area 413 allows the user to confirm the area in which the object 30 cannot be positioned.

Furthermore, on the positioning area map 410, icons 440_A, 440_B, 440_C, 440_D, 440_E, 440_F, 440_G, 440_H, 440_I, 440_J, 440_K, and 440_L indicating communication devices 200_A, 200_B, 200_C, 200_D, 200_E, 200_F, 200_G, 200_H, 200_I, 200_J, 200_K, and 200_L are displayed at positions on the map where communication devices 200_A, 200_B, 200_C, 200_D, 200_E, 200_F, 200_G, 200_H, 200_I, 200_J, 200_K, and 200_L are located. In the following, icons 440_A, 440_B, 440_C, 440_D, 440_E, 440_F, 440_G, 440_H, 440_I, 440_J, 440_K, and 440_L are also collectively referred to as "icons 440." This allows the user to check, for example, positionable area 411 and non-positionable area 413 and the position of each icon 440, and consider in which positions communication devices 200 should be added to reduce the non-positionable area, and in which positions communication devices 200 are not needed.

Refer to FIG. 16. When displaying a measurable area map, the user uses the AP selection button 423 to specify the target communication device 200. For example, when the user selects the AP selection button 423 using the input device 304, a list containing the names of the communication devices 200 (access points) that are candidates for display is displayed. The user uses the input device 304 to select an item for one communication device 200 from the list. In this state, it becomes possible to display the measurable area map 430 for the selected communication device 200 on the map display unit 400.

The user selects the measurable area display button 424 using the input device 304. This causes a measurable area map 430 of the target area 20 to be displayed on the map display section 400. The measurable area map 430 is a map in which a measurable area 431 and an unmeasurable area 433 are superimposed on a map of the target area 20. The area surrounded by a thick line in the figure is a set measurable area 432 set by the user. Note that in the examples shown in Figures 15 and 16, the set positioning area 412 and the set measurable area 432 are the same.

The measurable area 431 is included in the set measurable area 432. The non-measurable area 433 is an area in the set measurable area 432 other than the measurable area 431. The measurable area 431 and the non-measurable area 433 are displayed, for example, in different colors. This allows the user to easily distinguish between the measurable area 431 and the non-measurable area 433. The measurable area 431 allows the user to confirm the area in which the target communication device 200 can measure distances, and the non-measurable area 433 allows the user to confirm the area in which the target communication device 200 cannot measure distances.

Furthermore, in the measurable area map 430, similar to the measurable area map 410, a plurality of icons 440 are displayed at positions in the map where each communication device 200 is located. Furthermore, the icon 440 corresponding to the selected communication device 200 is displayed in a manner (color, shape, size, etc.) different from the other icons 440 that are not selected. In the example of FIG. 16, the icon 440_H is highlighted. This allows the user to easily confirm where the selected communication device 200 is located. For example, the user can understand the range of the measurable area of the selected communication device 200 by checking the icon 440 corresponding to the selected communication device 200, the measurable area 431, and the non-measurable area 433.

The positioning area display button 422 and the measurable area display button 424 are display components that can be exclusively selected. In other words, when the positioning area display button 422 is selected, the measurable area display button 424 is deselected, and when the measurable area display button 424 is selected, the positioning area display button 422 is deselected. As a result, in the map display section 400, the positioning area map 410 and the measurable area map 430 can be exclusively displayed.

Furthermore, it is preferable that the coordinate positions and scale of the positionable area map 410 are the same as the coordinate positions and scale of the measurable area map 430. This allows the user to easily compare the positionable area 411 and the measurable area 431 by switching the display between the positionable area map 410 and the measurable area map 430.

[5. Variations]
[5-1. First modified example]
The third estimation unit 370 of the server 300 may estimate the measurable area for each communication device 200 based on the position of the object 30 whose distance is measured by the communication device 200. That is, in this modification, the third estimation unit 370 estimates the measurable area 431 without directly using the distance measurement information obtained from the communication device 200. For example, the third estimation unit 370 can determine the measurable area 431 as the union of areas of a predetermined width between the position of the object 30 whose distance is measured by the focused communication device 200 and the position of the focused communication device 200.

[5-2. Second modified example]
The third estimation unit 370 of the server 300 may estimate the measurable area for each communication device 200 based on the position of the object 30 whose distance was not measured by the communication device 200. That is, in this modification, the third estimation unit 370 estimates the measurable area 431 without directly using the distance measurement information obtained from the communication device 200. For example, the third estimation unit 370 can estimate the measurable area 431 by deleting from the set measurable area 432 an area outside (in a direction moving away from the focused communication device 200) the position of the object 30 whose distance could not be measured by the focused communication device 200.

[5-3. Third modified example]
The communication device 200 may be capable of measuring the distance to the object 30 by a plurality of distance measurement methods. For example, the communication device 200 may be capable of distance measurement by UWB and distance measurement by Bluetooth. The communication device 200 transmits first distance measurement information indicating the distance measurement result by UWB and second distance measurement information indicating the distance measurement result by Bluetooth. The server 300 receives the first distance measurement information and the second distance measurement information, and stores the received first distance measurement information and second distance measurement information in the non-volatile memory 302. The server 300 estimates the first distance measurement possible area based on the distance measurement result by UWB, and estimates the second distance measurement possible area based on the distance measurement result by Bluetooth. The server 300 creates a first distance measurement possible area map based on the first distance measurement possible area, and creates a second distance measurement possible area map based on the second distance measurement possible area. The server 300 causes the display device 305 to display the first measurable area map and the second measurable area map, thereby allowing the user to check the measurable areas according to a plurality of measurable methods.

[5-4. Fourth modified example]
When one object 30 can be measured by only two communication devices 200, the first estimation unit 350 of the server 300 may determine the position of the object based on the distance measurement results by the two communication devices 200 and an area in which the presence of the object 30 is estimated. The area in which the presence of the object 30 is estimated (hereinafter referred to as the "presence estimation area") is, for example, an area including the previously measured position of the object 30, for example, a circular area with a predetermined radius centered on the position of the object 30. For example, the first estimation unit 350 can determine, within the presence estimation area, a position away from each of the two communication devices by the distances measured by the two communication devices 200 as the position of the object 30.

[5-5. Other variations]
In the above-described embodiment, the display device 305 displays the positionable area map 410 and the measurable area map 430, but this is not limiting. For example, a speaker may be provided in the server 300, and the speaker may output at least one of the information related to the positionable area 411 and the information related to the measurable area 431 by voice. The information related to the positionable area 411 may indicate, for example, that a specific object 30 is measurable or not measurable. The information related to the measurable area 431 may indicate, for example, that a specific object 30 is measurable or not measurable from a specific communication device 200.

In the above-described embodiment, the display device 305 of the server 300 displays the positioning system screen, but this is not limited to this. The server 300 may transmit data for displaying the positioning system screen to an information terminal (e.g., a computer, a smartphone, a tablet) capable of communicating with the server 300, and the information terminal may display the positioning system screen based on the data.

The set positioning area may be a past positionable area. The second estimation unit 360 compares the positionable area with the set positioning area to estimate the non-positionable area. For example, if the non-positionable area is larger than a predetermined area value, the output unit 390 may output an alarm as information regarding the non-positionable area, since a malfunction of the communication device 200 or the communication terminal 100 may occur.

The set measurement area may be a past measurement-enabled area. The fourth estimation unit 380 compares the measurement-enabled area with the set measurement area to estimate the measurement-disabled area. For example, if the measurement-disabled area is larger than a predetermined area value, the output unit 390 may output an alarm as information regarding the measurement-disabled area, since a malfunction of the communication device 200 or the communication terminal 100 may occur.

[6. Effects]
The positioning system 10 includes a communication terminal 100, a plurality of communication devices 200, and a server 300. The communication terminal 100 is attached to an object 30 arranged in a target area 20. The communication device 200 measures the distance to the object 30 by wirelessly communicating with the communication terminal 100. The server 300 receives distance measurement information indicating the measurement result of the distance from each of the plurality of communication devices 200. The server 300 includes a positioning unit 330, a storage unit 320, a first estimation unit 350, and an output unit 390. The positioning unit 330 measures the position of the object 30 based on the distance measurement information received from three or more communication devices 200. The storage unit 320 stores the positioning information indicating the measurement result by the positioning unit 330. The first estimation unit 350 estimates a positioning possible area 411 based on the positioning information stored in the storage unit 320. The output unit 390 outputs information relating to the positionable area 411 estimated by the first estimation unit 350. In this way, information relating to the positionable area 411 in the target area 20 can be provided to the user.

The information regarding the positionable area 411 may be a positionable area map 410 in which the positionable area 411 is superimposed on a map of the target area 20. This makes it possible to provide the user with information that allows the positionable area 411 to be visually recognized.

The server 300 may further include a second estimation unit 360. The second estimation unit 360 compares the positioning possible area 411 with a set positioning area 412 in the target area 20, and estimates a positioning impossible area 413 within the set positioning area 412, which is an area in which positioning by the positioning unit 330 is impossible. The output unit 390 may output information regarding the positioning impossible area 413. In this way, in addition to information regarding the positioning possible area 411, information regarding an area in the target area 20 in which positioning is impossible can be provided to the user.

The memory unit 320 may store the distance measurement information received from each of the multiple communication devices 200. The server 300 may further include a third estimation unit 370. The third estimation unit 370 estimates a distance measurement area 431, which is an area where the communication device 200 can measure distance, for each communication device 200 based on the distance measurement information stored in the memory unit 320. The output unit 390 may output information related to the distance measurement area 431 estimated by the third estimation unit 370. This makes it possible to provide the user with information related to the area in the target area 20 where distance measurement is possible by each communication device 200, in addition to information related to the position measurement area 411.

The third estimation unit 370 may estimate the measurable area 431 for each communication device 200 further based on the position of the object 30 whose distance is measured by the communication device 200. This allows the measurable area 431 to be estimated with higher accuracy.

The third estimation unit 370 may estimate the measurable area 431 for each communication device 200 based further on the position of the object 30 whose distance was not measured by the communication device 200. This allows the measurable area 431 to be estimated with higher accuracy.

The server 300 may further include a third estimation unit 370. The third estimation unit 370 estimates, for each communication device 200, a measurable area 431, which is an area in which the communication device 200 can measure the distance, based on the position of the object 30, the distance of which is measured by the communication device 200. The output unit 390 may output information on the measurable area 431 estimated by the third estimation unit 370. This makes it possible to generate information on the area in which the communication device 200 can measure the distance, based on the position of the object 30, the distance of which is measured by the communication device 200.

The server 300 may further include a third estimation unit 370. The third estimation unit 370 estimates, for each communication device 200, a measurable area 431, which is an area in which the communication device 200 can measure distance, based on the position of the object 30 whose distance has not been measured by the communication device 200. The output unit 390 may output information about the measurable area 431 estimated by the third estimation unit 370. This makes it possible to generate information about the area in which the communication device 200 can measure distance, based on the position of the object 30 whose distance has not been measured by the communication device 200.

The information regarding the measurable area 431 may be a measurable area map 430 in which the measurable area 431 is superimposed on a map of the target area 20. This makes it possible to provide the user with information that allows the measurable area 431 to be visually recognized.

The server 300 may further include a fourth estimation unit 380. The fourth estimation unit 380 compares the measurable area 431 with a set measurable area 432 in the target area 20, and estimates an unmeasurable area 433 within the set measurable area 432, which is an area in which measurable distances cannot be performed by the communication device 200. This makes it possible to identify areas in which measurable distances cannot be performed by the communication device 200.

The communication device 200 may measure the distance to the object 30 by wirelessly communicating with the communication terminal 100 via a first radio and transmit the first distance measurement information. The communication device 200 may measure the distance to the object 30 via a second radio different from the first radio and transmit the second distance measurement information. The positioning unit 330 may measure the position of the object 30 based on the first distance measurement information received from three or more communication devices 200 and output the first positioning information. The positioning unit 330 may measure the position of the object 30 based on the second distance measurement information and output the second positioning information. The storage unit 320 may store the first positioning information and the second positioning information. The first estimation unit 350 may estimate the first positioning possible area based on the first positioning information. The first estimation unit 350 may estimate the second positioning possible area based on the second positioning information. The output unit 390 may output a first map indicating the first positioning possible area and a second map indicating the second positioning possible area. This allows the user to be provided with a first map and a second map obtained using two different types of radio.

When ranging information on one object 30 is received from two communication devices 200, the positioning unit 330 may determine the position of the object 30 based on the ranging information and the area in which the presence of the object 30 is estimated, and generate information indicating the determined position as positioning information. In this way, even if ranging is not possible with three communication devices 200, it is possible to determine the position of an object 30 whose ranging can be measured by two communication devices 200.

The server 300 may further include a determination unit 340. The determination unit 340 determines the reliability of the positioning information based on the number of communication devices 200 from which distance measurement information has been obtained for each object 30. This makes it possible to identify highly reliable positioning information.

The communication terminal 100 may include a display unit 140. The display unit 140 displays that positioning is possible based on the number of communication devices 200 that have performed wireless communication. This allows the user to recognize whether or not the object 30 is a positionable object based on the display on the display unit 140.

The communication device 200 may transmit ranging reliability information indicating the reliability of the ranging information to the server 300. The storage unit 320 may store the ranging reliability information received from the communication device 200. This makes it possible to obtain information indicating the reliability of each piece of ranging information.

[7. Supplementary Notes]
The embodiments disclosed herein are illustrative in all respects and are not restrictive. The scope of the present invention is defined by the claims rather than the above-described embodiments, and includes the meaning equivalent to the claims and all modifications within the scope thereof.

10 Positioning system 20 Target area 30, 30_A, 30_B, 30_C, 30_D, 30_E, 30_F, 30_G, 30_H, 30_I Object 100, 100_A, 100_B, 100_C, 100_D, 100_E, 100_F, 100_G, 100_H, 100_I Communication terminal 101 Processor 102 Non-volatile memory 103 Volatile memory 104 Communication interface 104A Antenna 105A, 105B LED
106 Determination program 110 Wireless communication unit 120 Processing time measurement unit 130 Determination unit 140 Display unit 200, 200_A, 200_B, 200_C, 200_D, 200_E, 200_F, 200_G, 200_H, 200_I, 200_J, 200_K, 200_L Communication device 201 Processor 202 Non-volatile memory 203 Volatile memory 204 First communication interface (I/F)
204A Antenna 205 Second communication interface (I/F)
206 Distance measurement program 210 Wireless communication unit 220 Communication time measurement unit 230 Distance measurement unit 240 Transmission unit 300 Server 301 Processor 302 Non-volatile memory 303 Volatile memory 304 Input device 305 Display device 306 Communication interface (I/F)
307 Estimation program 310 Receiving unit 320 Storage unit 330 Positioning unit 340 Determination unit 350 First estimation unit 360 Second estimation unit 370 Third estimation unit 380 Fourth estimation unit 390 Output unit 400 Map display unit 410 Positioning possible area map 411 Positioning possible area 412 Set positioning area 413 Positioning impossible area 421 Area selection button 422 Positioning possible area display button 423 AP selection button 424 Measurable area display button 430 Measurable area map 431 Measurable area 432 Set measurable area 433 Measurable impossible area 440, 440_A, 440_B, 440_C, 440_D, 440_E, 440_F, 440_G, 440_H, 440_I, 440_J, 440_K, 440_L Icon M1 Distance measurement information table M2 Positioning information table

Claims (17)

a communication terminal attached to an object located in a target area;
a plurality of communication devices that measure distances to the object by wirelessly communicating with the communication terminal;
a server that receives distance measurement information indicating a distance measurement result from each of the plurality of communication devices;
Equipped with
The server,
a positioning unit that measures a position of the object based on the distance measurement information received from three or more communication devices;
a storage unit that stores positioning information indicating a measurement result by the positioning unit;
a first estimation unit that estimates a positioning available area based on a surrounding area including a position of the object indicated by the positioning information stored in the storage unit;
an output unit that outputs information about the positioning available area estimated by the first estimation unit;
Including,
Positioning system. The information regarding the positioning available area is a positioning available area map in which the positioning available area is superimposed on a map of the target area.
The positioning system according to claim 1 . the server further includes a second estimation unit that compares the positioning possible area with a set positioning area in the target area and estimates a positioning impossible area within the set positioning area, the positioning impossible area being an area in which positioning by the positioning unit is impossible;
The output unit outputs information related to the positioning impossible area.
The positioning system according to claim 1 or 2. the storage unit stores the distance measurement information received from each of the plurality of communication devices;
the server further includes a third estimation unit that estimates, for each of the communication devices, a distance measurement enabled area, which is an area in which a distance can be measured by the communication devices, based on the distance measurement information stored in the storage unit;
the output unit outputs information regarding the distance measurement area estimated by the third estimation unit.
The positioning system according to any one of claims 1 to 3. the third estimation unit estimates the distance measurable area for each of the communication devices further based on a position of an object whose distance is measured by the communication device.
The positioning system according to claim 4. the third estimation unit estimates the distance measurable area for each of the communication devices further based on a position of an object to which the distance has not been measured by the communication device;
The positioning system according to claim 4 or 5. the server further includes a third estimation unit that estimates, for each of the communication devices, a measurable area in which distances can be measured by the communication devices, based on a position of an object whose distance is measured by the communication devices;
the output unit outputs information regarding the distance measurement area estimated by the third estimation unit.
The positioning system according to any one of claims 1 to 3. the server further includes a third estimation unit that estimates, for each of the communication devices, a measurable area in which the distance can be measured by the communication devices, based on a position of an object to which the distance has not been measured by the communication devices;
the output unit outputs information regarding the distance measurement area estimated by the third estimation unit.
The positioning system according to any one of claims 1 to 3. the information about the measurable area is a measurable area map in which the measurable area is superimposed on a map of the target area;
The positioning system according to any one of claims 4 to 8. the server further includes a fourth estimation unit that compares the measurable area with a set measurable area in the target area and estimates a measurable area within the set measurable area that is an area in which measurment by the communication device is not possible,
The output unit outputs information regarding the distance measurement impossible area.
The positioning system according to any one of claims 4 to 9. the communication device measures a distance to the object by wirelessly communicating with the communication terminal using a first radio wave and transmits first distance measurement information, and measures a distance to the object using a second radio wave different from the first radio wave and transmits second distance measurement information;
the positioning unit measures a position of the object based on the first distance measurement information received from three or more communication devices, and outputs the first positioning information, and measures a position of the object based on the second distance measurement information, and outputs the second positioning information;
The storage unit stores the first positioning information and the second positioning information,
The first estimation unit estimates a first positioning available area based on the first positioning information and estimates a second positioning available area based on the second positioning information;
the output unit outputs a first map indicating the first positioning available area and a second map indicating the second positioning available area.
The positioning system according to any one of claims 1 to 10. when the distance measurement information regarding one object is received from two communication devices, the positioning unit determines a position of the object based on the distance measurement information and an area in which the existence of the object is estimated, and generates information indicating the determined position as the positioning information.
A positioning system according to any one of claims 1 to 11. the server further includes a determination unit that determines a reliability of the positioning information based on the number of the communication devices from which the distance measurement information is obtained for each of the objects.
A positioning system according to any one of claims 1 to 12. the communication terminal includes a display unit that displays that positioning is possible based on the number of the communication devices that have performed wireless communication;
A positioning system according to any one of claims 1 to 13. the communication device transmits distance measurement reliability information indicating reliability of the distance measurement information to the server;
The storage unit stores the ranging reliability information received from the communication device.
A positioning system according to any one of claims 1 to 14. a receiving unit that receives distance measurement information indicating a result of distance measurement from each of a plurality of communication devices that measure a distance to an object by wirelessly communicating with a communication terminal attached to the object placed in a target area;
a positioning unit that measures a position of the object based on the distance measurement information received by the receiving unit from three or more communication devices;
a storage unit that stores positioning information indicating a measurement result by the positioning unit;
a first estimation unit that estimates a positioning available area based on a surrounding area including a position of the object indicated by the positioning information stored in the storage unit;
an output unit that outputs information about the positioning available area estimated by the first estimation unit;
Equipped with
server. a first communication unit that wirelessly communicates with a communication terminal attached to an object placed in a target area;
a distance measuring unit that measures a distance to the object by wirelessly communicating with the communication terminal via the first communication unit;
A second communication unit that communicates with the server;
Equipped with
the second communication unit transmits distance measurement information indicating a result of distance measurement by the distance measuring unit to the server, so that the server measures the position of the object, estimates a position measurement area based on a surrounding area including the measured position of the object, and outputs information related to the estimated position measurement area.
Communications equipment.

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