Information terminal, information processing method and program

Abstract

To enable smooth positioning by wirelessly connecting an information terminal with a plurality of positioning devices. [Solution] Information terminal 1 is an information terminal that performs positioning by wirelessly connecting with a positioning device, and has a connection unit 131 that wirelessly connects with a first positioning device, a distance measurement unit 132 that measures the distance between the information terminal and the first positioning device while the connection unit is wirelessly connected to the first positioning device, and an acquisition unit 133 that acquires a list showing multiple positioning devices that are pre-associated with the first positioning device, and the connection unit wirelessly connects with a second positioning device included in the list, provided that the distance between the information terminal and the first positioning device is less than a first reference distance.

Description

[Technical Field]

[0001] The present invention relates to an information terminal, an information processing method, and a program for performing positioning by wirelessly connecting to a positioning device. [Background technology]

[0002] Patent Document 1 describes a system that calculates the position of an information terminal by transmitting and receiving UWB (ultra-wideband) radio signals between the information terminal to be positioned and a positioning device (also called an anchor). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2023-96454 Summary of the Invention [Problem to be solved by the invention]

[0004] In the system described in Patent Document 1, an information terminal performs positioning by transmitting and receiving wireless signals to and from three or more positioning devices. Since there is a limit to the number of positioning devices that an information terminal can simultaneously connect wirelessly to, if the information terminal continues to connect wirelessly to a positioning device that does not contribute to positioning (such as a positioning device that is far away from the information terminal), it will be unable to connect wirelessly to a new positioning device, which can result in positioning being impossible or the accuracy of positioning being reduced.

[0005] The present invention has been made in view of these points, and has as its object to enable an information terminal to smoothly perform positioning by wirelessly connecting with a plurality of positioning devices. [Means for solving the problem]

[0006] The information terminal of a first aspect of the present invention is an information terminal that performs positioning by wirelessly connecting with positioning devices, and has a connection unit that wirelessly connects with multiple positioning devices, a distance measurement unit that measures the distance between the information terminal and a target positioning device among the multiple positioning devices while the connection unit is wirelessly connected to the target positioning device among the multiple positioning devices, and a disconnection unit that disconnects the wireless connection with at least one of the multiple positioning devices, provided that the distance between the information terminal and the target positioning device is less than a disconnection reference distance and the number of the multiple positioning devices is equal to or greater than the reference number.

[0007] The disconnection unit may disconnect the wireless connection with the target positioning device on condition that the distance between the information terminal and the target positioning device is equal to or greater than the disconnection reference distance.

[0008] The disconnection unit may disconnect the wireless connection with the at least one positioning device in descending order of distance from the information terminal so that the number of devices becomes less than the reference number.

[0009] The information terminal may further have an acquisition unit that acquires a list indicating a plurality of specified positioning devices that are pre-associated with the target positioning device, and the disconnection unit may disconnect the wireless connection with at least one positioning device among the plurality of positioning devices that is not included in the list, provided that the distance between the information terminal and the target positioning device is less than the disconnection reference distance.

[0010] The connection unit may establish a wireless connection with the target positioning device on condition that the distance between the information terminal and the target positioning device is less than a connection reference distance, and the disconnection unit may disconnect the wireless connection with at least one positioning device among the plurality of positioning devices that is not included in the list on condition that the distance between the information terminal and the target positioning device is less than the disconnection reference distance and the distance between the information terminal and the target positioning device is less than the connection reference distance.

[0011] A second aspect of the information processing method of the present invention includes the steps of establishing a wireless connection with a plurality of positioning devices, executed by an information terminal that performs positioning by wirelessly connecting with positioning devices; measuring the distance between the information terminal and a target positioning device among the plurality of positioning devices while the information terminal is wirelessly connected to the target positioning device; and disconnecting the wireless connection with at least one of the plurality of positioning devices, provided that the distance between the information terminal and the target positioning device is less than a disconnection reference distance and the number of the plurality of positioning devices is equal to or greater than a reference number.

[0012] A third aspect of the program of the present invention causes an information terminal that performs positioning by wirelessly connecting with positioning devices to execute the following steps: wirelessly connecting with a plurality of positioning devices; measuring the distance between the information terminal and a target positioning device among the plurality of positioning devices while the information terminal is wirelessly connected to the target positioning device; and disconnecting the wireless connection with at least one of the plurality of positioning devices, provided that the distance between the information terminal and the target positioning device is less than a disconnection reference distance and the number of the plurality of positioning devices is equal to or greater than a reference number.

[0013]

[0014]

[0015]

[0016]

[0017] [Effects of the Invention]

[0018] According to the present invention, it is possible to provide an effect that an information terminal can smoothly perform positioning by wirelessly connecting with a plurality of positioning devices. [Brief explanation of the drawings]

[0019] [Figure 1]FIG. 1 is a schematic diagram of an information processing system. [Figure 2] FIG. 1 is a block diagram of an information processing system. [Figure 3] FIG. 1 is a schematic diagram illustrating an exemplary arrangement of multiple positioning devices. [Figure 4] FIG. 10 is a schematic diagram for explaining a reference distance. [Figure 5] 10 is a schematic diagram for explaining a process in which an information terminal wirelessly connects to a positioning device; FIG. [Figure 6] FIG. 4 is a schematic diagram for explaining the first positioning process. [Figure 7] FIG. 10 is a schematic diagram for explaining the second positioning process. [Figure 8] FIG. 10 is a schematic diagram for explaining a process of reconnecting an information terminal with a positioning device. [Figure 9] FIG. 10 is a flowchart illustrating an exemplary information processing method executed by an information terminal. [Figure 10] FIG. 10 is a flowchart illustrating an exemplary information processing method executed by an information terminal. [Figure 11] FIG. 10 is a flowchart illustrating an exemplary information processing method executed by an information terminal. DETAILED DESCRIPTION OF THE INVENTION

[0020] [Outline of Information Processing System S] 1 is a schematic diagram of an information processing system S according to this embodiment. The information processing system S includes an information terminal 1 and a plurality of positioning devices 2. The information processing system S may also include other terminals, servers, devices, etc.

[0021] The information terminal 1 is a computer used by a user. The user is, for example, a person who holds the information terminal 1. The information terminal 1 is, for example, a computer such as a smartphone or a tablet terminal. The information terminal 1 has, for example, a display unit such as a liquid crystal display for displaying information, and an operation unit such as a touch panel for receiving operations by the user. The information terminal 1 performs positioning of the information terminal 1 by wirelessly connecting with one or more positioning devices 2. The number of multiple positioning devices 2 that the information terminal 1 can simultaneously connect to wirelessly is limited to a predetermined number or less (for example, six or less) due to communication specifications.

[0022] The positioning device 2 is a device that transmits and receives wireless signals to and from the information terminal 1. The positioning device 2 has a communication unit for transmitting and receiving wireless signals of short-range wireless communication such as Bluetooth (registered trademark) and wireless signals of UWB (Ultra Wide Band).

[0023] An outline of the process executed by the information processing system S according to this embodiment will be explained below. The information terminal 1 is wirelessly connected to a first positioning device 2a, which is one of the positioning devices 2, among the plurality of positioning devices 2.

[0024] The information terminal 1 measures the distance between the information terminal 1 and the first positioning device 2a while being wirelessly connected to the first positioning device 2a. The information terminal 1 measures the distance between the information terminal 1 and the first positioning device 2a, for example, by using the time it takes to transmit and receive a wireless signal between the information terminal 1 and the first positioning device 2a.

[0025] The information terminal 1 acquires a list indicating a plurality of positioning devices 2 that are pre-associated with the first positioning device 2a. The list is, for example, information indicating a plurality of positioning devices 2 that are close to the first positioning device 2a, and is pre-stored in a storage unit of the information terminal 1 or another storage device.

[0026] On the condition that the distance between the information terminal 1 and the first positioning device 2a is less than a predetermined reference distance, the information terminal 1 establishes a wireless connection with a second positioning device 2b included in the list of the multiple positioning devices 2. The information terminal 1 measures the position of the information terminal 1 using the positions of one or more positioning devices 2 with which it is wirelessly connected.

[0027] In this way, in the information processing system S, the information terminal 1 establishes a wireless connection with the first positioning device 2a, and then establishes a wireless connection with the second positioning device 2b included in a list previously associated with the first positioning device 2a, thereby locating the position of the information terminal 1. In this way, the information processing system S prevents the information terminal 1 from establishing a wireless connection with a positioning device 2 that does not contribute to positioning (for example, a positioning device 2 that is far away from the information terminal 1), and makes it easier for the information terminal 1 to establish a wireless connection with a new positioning device 2, thereby enabling smooth positioning of the information terminal 1.

[0028] [Configuration of Information Processing System S] FIG. 2 is a block diagram of an information processing system S according to this embodiment. In FIG. 2, arrows indicate main data flows, and data flows other than those shown in FIG. 2 may also exist. In FIG. 2, each block indicates a functional configuration rather than a hardware (device) configuration. Therefore, the blocks shown in FIG. 2 may be implemented in a single device, or may be implemented separately in multiple devices. Data may be exchanged between blocks via any means, such as a data bus, a network, or a portable storage medium.

[0029] The information terminal 1 has a communication unit 11, a storage unit 12, and a control unit 13. The information terminal 1 may be configured by connecting two or more physically separate devices via wired or wireless connections. Furthermore, at least some of the functions of the information terminal 1 may be executed by a cloud, which is a collection of computer resources.

[0030] The communication unit 11 has a communication controller for transmitting and receiving data to and from the information terminal 1 via a network. The communication unit 11 notifies the control unit 13 of information indicated by a wireless signal received from the positioning device 2. The communication unit 11 also transmits a wireless signal indicating the information output from the control unit 13 to the positioning device 2.

[0031] The storage unit 12 is a storage medium including a ROM (Read Only Memory), a RAM (Random Access Memory), a hard disk drive, an SSD (Solid State Drive), etc. The storage unit 12 stores in advance programs to be executed by the control unit 13. The storage unit 12 may be provided outside the information terminal 1, in which case data may be exchanged between the storage unit 12 and the control unit 13 via a network.

[0032] The control unit 13 has a connection unit 131, a distance measurement unit 132, an acquisition unit 133, a disconnection unit 134, and a positioning unit 135. The control unit 13 is a processor such as a CPU (Central Processing Unit), and functions as the connection unit 131, the distance measurement unit 132, the acquisition unit 133, the disconnection unit 134, and the positioning unit 135 by executing a program stored in the storage unit 12.

[0033] Hereinafter, a detailed description will be given of the processing executed by the information processing system S. First, a description will be given of the arrangement of a plurality of positioning devices 2 in this embodiment. Fig. 3 is a schematic diagram for explaining an exemplary arrangement of a plurality of positioning devices 2.

[0034] A plurality of positioning devices 2 are placed in a predetermined placement area (exhibition hall, store, etc.). The information terminal 1 identifies the position of the information terminal 1 by wirelessly connecting with one or more positioning devices 2, and provides the user with information (exhibit descriptions, product descriptions, etc.) according to the identified position.

[0035] The multiple positioning devices 2 are fixed to, for example, the ceiling of the placement area. The memory unit 12 of the information terminal 1 or another memory device stores in advance information indicating the position (coordinates, etc.) of each of the multiple positioning devices 2. The information indicating the position of each of the multiple positioning devices 2 is created in advance, for example, by an administrator who manages the multiple positioning devices 2, and stored in the memory unit 12 of the information terminal 1 or another memory device.

[0036] Furthermore, the memory unit 12 of the information terminal 1 or another storage device pre-stores a list indicating a plurality of positioning devices 2 pre-associated with each of the plurality of positioning devices 2. The list is created in advance by, for example, an administrator who manages the plurality of positioning devices 2, and is stored in the memory unit 12 of the information terminal 1 or another storage device.

[0037] The multiple positioning devices 2 associated with one positioning device 2 are, for example, a predetermined number of positioning devices 2 arranged in order of proximity to the one positioning device 2. Furthermore, the multiple positioning devices 2 associated with one positioning device 2 may be, for example, a predetermined number of positioning devices 2 that a user moving along a predetermined route within the placement area may approach after approaching the one positioning device 2. In the example of Figure 3, a list showing multiple devices (d, e, f in Figure 3) associated with one positioning device 2 (c in Figure 3) is stored in advance.

[0038] Next, a description will be given of the reference distance used in this embodiment to determine whether or not wireless connection between the information terminal 1 and the positioning device 2 is possible. Figures 4(a) and 4(b) are schematic diagrams for explaining the reference distance.

[0039] In this embodiment, the reference distance includes, for example, a first reference distance (also referred to as a positioning reference distance) that serves as a reference for switching positioning processing, and a second reference distance (also referred to as a disconnection reference distance) that serves as a reference for disconnecting a wireless connection.

[0040] When there is a positioning device 2 whose distance to the information terminal 1 is less than the first reference distance (as in FIG. 4(a)), the positioning unit 135 described below executes a positioning process that performs positioning using the position of one positioning device 2. On the other hand, when there is no positioning device 2 whose distance to the information terminal 1 is less than the first reference distance (as in FIG. 4(b)), the positioning unit 135 described below executes a positioning process that performs positioning using the positions of multiple positioning devices 2.

[0041] In addition, the disconnection unit 134 described below disconnects the wireless connection between the information terminal 1 and the positioning device 2 when the distance between the information terminal 1 and the positioning device 2 is equal to or greater than a second reference distance while the information terminal 1 and the positioning device 2 are wirelessly connected.

[0042] Next, a description will be given of a process in which the information terminal 1 establishes a wireless connection with the positioning device 2. Figures 5(a) and 5(b) are schematic diagrams for explaining a process in which the information terminal 1 establishes a wireless connection with the positioning device 2.

[0043] Each of the positioning devices 2 repeatedly transmits a radio signal (e.g., an advertising signal) for short-range wireless communication. The radio signal for short-range wireless communication includes, for example, information for establishing a wireless connection for short-range wireless communication with the positioning device 2 that is the transmission source.

[0044] The connection unit 131 receives a radio signal for short-range wireless communication from any one of the positioning devices 2. When the connection unit 131 receives radio signals for short-range wireless communication from a plurality of positioning devices 2, the connection unit 131 performs the following process for each of the plurality of positioning devices 2.

[0045] The connection unit 131 identifies the received signal strength (for example, RSSI (Received Signal Strength Indicator)) when receiving a wireless signal for short-range wireless communication. If the received signal strength is equal to or greater than a predetermined reference strength, the connection unit 131 establishes a wireless connection for short-range wireless communication with the positioning device 2 that is the source of the wireless signal. On the other hand, if the received signal strength is less than the reference strength, the connection unit 131 ends the process without establishing a wireless connection for short-range wireless communication with the positioning device 2 that is the source of the wireless signal.

[0046] The connection unit 131 receives connection information for establishing a UWB wireless connection from the positioning device 2 with which it has a wireless connection via short-range wireless communication, via short-range wireless communication. The connection unit 131 establishes a UWB wireless connection with the positioning device 2 with which it has a wireless connection via short-range wireless communication, using the received connection information. When it is not necessary to receive connection information for establishing a UWB wireless connection via short-range wireless communication, the connection unit 131 may establish a UWB wireless connection with the positioning device 2 without establishing a wireless connection via short-range wireless communication.

[0047] While the connection unit 131 is wirelessly connected to the positioning device 2, the distance measurement unit 132 measures the distance between the information terminal 1 and the positioning device 2 that is wirelessly connected to the information terminal 1. For example, the distance measurement unit 132 measures the distance between the information terminal 1 and the positioning device 2 by using the time it takes from transmitting a UWB wireless signal to the positioning device 2 to receiving the UWB wireless signal transmitted by the positioning device 2. The distance measurement unit 132 is not limited to the specific method shown here, and may measure the distance between the information terminal 1 and the positioning device 2 by other methods.

[0048] Hereinafter, any one of the multiple positioning devices 2 to which the connection unit 131 is wirelessly connected will be referred to as the first positioning device 2a. When the connection unit 131 is wirelessly connected to multiple positioning devices 2, the information terminal 1 may select any one of the multiple positioning devices 2 to which it is wirelessly connected (for example, the positioning device 2 to which the distance measured by the distance measuring unit 132 is the shortest) as the first positioning device 2a. When the multiple positioning devices 2 to which the connection unit 131 is wirelessly connected are changed, the information terminal 1 may newly select a positioning device 2 different from the already selected first positioning device 2a as the first positioning device 2a.

[0049] The connection unit 131 determines whether the distance between the information terminal 1 and the first positioning device 2a measured by the distance measurement unit 132 is less than a predetermined first reference distance. The first reference distance is a predetermined distance used as a reference for switching positioning processes, and is designated in advance by, for example, an administrator who manages multiple positioning devices 2. Fig. 5(a) shows a case where the distance between the information terminal 1 and the first positioning device 2a is less than the first reference distance, and Fig. 5(b) shows a case where the distance between the information terminal 1 and the first positioning device 2a is equal to or greater than the first reference distance.

[0050] When the distance between the information terminal 1 and the first positioning device 2a is less than the first reference distance, the acquisition unit 133 acquires, from the storage unit 12 or another storage device, a list indicating a plurality of positioning devices pre-associated with the first positioning device 2a. The list is, for example, a predetermined number of positioning devices 2 arranged in order of proximity to the first positioning device 2a, or a predetermined number of positioning devices 2 that the user may approach after approaching the first positioning device 2a. On the other hand, when the distance between the information terminal 1 and the first positioning device 2a is equal to or greater than the first reference distance, the acquisition unit 133 does not need to acquire the list.

[0051] While the connection unit 131 is wirelessly connected to the first positioning device 2a, it receives a wireless signal for short-range wireless communication from a second positioning device 2b, which is a positioning device 2 different from the first positioning device 2a.

[0052] The connection unit 131 determines whether the distance between the information terminal 1 and the first positioning device 2a is less than a first reference distance, i.e., whether there is a first positioning device 2a that is less than the first reference distance. If the distance between the information terminal 1 and the first positioning device 2a is less than the first reference distance, the connection unit 131 establishes a wireless connection for short-range wireless communication with the second positioning device 2b, on the condition that the received signal strength of the radio signal for short-range wireless communication received from the second positioning device 2b is equal to or greater than a predetermined reference strength and the second positioning device 2b is included in the list acquired by the acquisition unit 133.

[0053] On the other hand, when the distance between the information terminal 1 and the first positioning device 2a is equal to or greater than the first reference distance, the connection unit 131 establishes a wireless connection for short-range wireless communication with the second positioning device 2b, provided that the received signal strength of the radio signal for short-range wireless communication received from the second positioning device 2b is equal to or greater than the reference strength.

[0054] The connection unit 131 receives connection information for establishing a UWB wireless connection from the second positioning device 2b, which is wirelessly connected via short-range wireless communication, via short-range wireless communication. The connection unit 131 uses the received connection information to establish a UWB wireless connection with the second positioning device 2b, which is wirelessly connected via short-range wireless communication.

[0055] In other words, the connection unit 131 establishes a wireless connection on the condition that the second positioning device 2b is included in the list when the distance between the information terminal 1 and the first positioning device 2a is less than the first reference distance, and establishes a wireless connection regardless of whether the second positioning device 2b is included in the list when the distance between the information terminal 1 and the first positioning device 2a is equal to or greater than the first reference distance.

[0056] In addition, when there is no need to receive connection information for establishing a UWB wireless connection via short-range wireless communication, the connection unit 131 may establish a UWB wireless connection with the second positioning device 2b without establishing a wireless connection via short-range wireless communication.

[0057] In this way, the connection unit 131 establishes a wireless connection with the first positioning device 2a, and then establishes a wireless connection with the second positioning device 2b included in the list of multiple positioning devices 2 pre-associated with the first positioning device 2a. This enables the information processing system S to encourage the information terminal 1 to establish a wireless connection with a second positioning device 2b that is close to the first positioning device 2a or a second positioning device 2b along the user's route, and to suppress wireless connection with a positioning device 2 that does not contribute to positioning.

[0058] The disconnection unit 134 disconnects (terminates) the wireless connection with the positioning device 2 that satisfies a predetermined disconnection condition in parallel with the process of the connection unit 131 establishing a wireless connection with the positioning device 2. For example, the disconnection unit 134 disconnects only the wireless connection of short-range wireless communication when the information terminal 1 and the positioning device 2 are not wirelessly connected by UWB, and disconnects both the short-range wireless communication and the UWB wireless connections when the information terminal 1 and the positioning device 2 are wirelessly connected by UWB.

[0059] For example, the disconnection unit 134 disconnects the wireless connection with the positioning device 2 whose distance from the information terminal 1 is equal to or greater than the second reference distance, and maintains the wireless connection with the positioning device 2 whose distance from the information terminal 1 is less than the second reference distance. The second reference distance is a predetermined distance greater than the first reference distance that is used as a criterion for disconnecting the wireless connection, and is specified in advance by, for example, an administrator who manages multiple positioning devices 2.

[0060] Furthermore, the disconnection unit 134 determines whether the distance between the information terminal 1 and the first positioning device 2a is less than a first reference distance, i.e., whether there is a first positioning device 2a that is less than the first reference distance. If the distance between the information terminal 1 and the first positioning device 2a is less than the first reference distance, the disconnection unit 134 disconnects the wireless connection with the positioning device 2 that is not included in the list acquired by the acquisition unit 133, and maintains the wireless connection with the positioning device 2 that is included in the list acquired by the acquisition unit 133.

[0061] Furthermore, the disconnection unit 134 may switch whether to disconnect the wireless connection depending on the relationship between the number of positioning devices 2 wirelessly connected by the connection unit 131 and a predetermined reference number. The reference number is the number of positioning devices 2 used as a reference for disconnecting the wireless connection, and is a number smaller than the maximum number of positioning devices 2 that the information terminal 1 can simultaneously connect wirelessly to.

[0062] For example, on the condition that the distance between the information terminal 1 and the first positioning device 2a is equal to or greater than a first reference distance and the number of multiple positioning devices 2 to which the connection unit 131 has wireless connection is equal to or greater than a reference number, the disconnection unit 134 disconnects the wireless connection with one or more positioning devices 2 in descending order of distance from the information terminal 1 measured by the distance measuring unit 132 so that the number of multiple positioning devices 2 to which the connection unit 131 has wireless connection becomes less than the reference number. In this way, the information processing system S controls the number of multiple positioning devices 2 to which the information terminal 1 has wireless connection so that it does not reach the maximum number, and can maintain a state in which the information terminal 1 can establish a wireless connection with a new positioning device 2.

[0063] Furthermore, when the distance between the information terminal 1 and the first positioning device 2a is less than the first reference distance, the connection unit 131 may establish a wireless connection with a second positioning device 2b that is not included in the list, on the condition that the number of positioning devices 2 to which the connection unit 131 has a wireless connection is less than the reference number. In other words, even if the second positioning device 2b is not included in the list, the connection unit 131 may establish a wireless connection with the second positioning device 2b if the number of positioning devices 2 to which the connection unit 131 has a wireless connection does not reach the reference number. This allows the information processing system S to flexibly allow the information terminal 1 to establish a wireless connection with the positioning devices 2 in a situation where the number of positioning devices 2 to which the information terminal 1 has a wireless connection is small.

[0064] Next, the process of positioning performed by the information terminal 1 will be described. The positioning unit 135 switches between the first positioning process and the second positioning process depending on the distance between the information terminal 1 and the first positioning device 2a. The positioning unit 135 determines whether the distance between the information terminal 1 and the first positioning device 2a is less than a first reference distance, that is, whether there is a first positioning device 2a that is less than the first reference distance. For example, the positioning unit 135 performs the first positioning process when the distance between the information terminal 1 and the first positioning device 2a is equal to or greater than the first reference distance, and performs the second positioning process when the distance between the information terminal 1 and the first positioning device 2a is less than the first reference distance.

[0065] 6 is a schematic diagram for explaining the first positioning process. When the distance between the information terminal 1 and the first positioning device 2a is equal to or greater than a first reference distance, the positioning unit 135 determines the position of the information terminal 1 by using the positions of each of the multiple positioning devices 2 including the first positioning device 2a and the second positioning device 2b and the distance between the information terminal 1 and each of the multiple positioning devices 2 including the first positioning device 2a and the second positioning device 2b.

[0066] In this embodiment, the positioning unit 135 calculates the position of the information terminal 1 using the positions and distances of four positioning devices 2, including a first positioning device 2a and multiple second positioning devices 2b, but in cases where multiple positioning devices are installed at the same height, the position of the information terminal 1 may also be calculated using the positions and distances of three positioning devices 2.

[0067] The positioning unit 135 acquires information indicating the positions (coordinates, etc.) of the first positioning device 2a and the plurality of second positioning devices 2b, for example, from the memory unit 12 or another storage device. The positioning unit 135 calculates the position of the information terminal 1 using the positions indicated by the acquired information and the distances measured by the distance measuring unit 132. The positioning unit 135 calculates the position of the information terminal 1 using, for example, known triangulation methods and sequential calculation methods (Newton's method), etc.

[0068] In this way, the information processing system S determines the position of the information terminal 1 using the distance measured by sending and receiving wireless signals between multiple positioning devices 2 and the information terminal 1, and therefore can measure the position of the information terminal 1 with high accuracy.

[0069] 7 is a schematic diagram for explaining the second positioning process. When the distance between the information terminal 1 and the first positioning device 2a is less than the first reference distance, the positioning unit 135 determines the position of the information terminal 1 using the position of the first positioning device 2a without using the position of the second positioning device 2b, as the second positioning process. The positioning unit 135 acquires information indicating the position (coordinates, etc.) of the first positioning device 2a from, for example, the memory unit 12 or another storage device. The positioning unit 135 determines the position of the first positioning device 2a indicated by the acquired information as the position of the information terminal 1.

[0070] 7 shows a situation in which the first reference distance is 3.5 m, the installation height of the first positioning device 2a is 4.4 m, and the information terminal 1 is located 1.0 m above the ground. In this situation, the position error of the information terminal 1 on a plane horizontal to the ground is a low value of approximately 0.83 m, so the position of the first positioning device 2a can be considered to be the position of the information terminal 1. In this way, the information processing system S specifies the position of the first positioning device 2a as the position of the information terminal 1 when the information terminal 1 and the first positioning device 2a are sufficiently close, so that the information processing system S can quickly measure the position of the information terminal 1 even in a situation in which the information terminal 1 is not wirelessly connected to three or more positioning devices 2.

[0071] Next, a description will be given of a process in which the information terminal 1 reconnects after disconnecting the wireless connection with the positioning device 2. Figures 8(a) and 8(b) are schematic diagrams for explaining the process in which the information terminal 1 reconnects with the positioning device 2.

[0072] 8(a), the connection unit 131 may reestablish wireless connection with the positioning device 2 on the condition that the information terminal 1 has moved a distance equal to or greater than a predetermined third reference distance after the wireless connection between the information terminal 1 and the positioning device 2 has been disconnected. The third reference distance is a predetermined distance used as a reference for reconnection and is designated in advance by, for example, an administrator who manages multiple positioning devices 2. In this case, the connection unit 131 determines that the information terminal 1 has moved a distance equal to or greater than the third reference distance, for example, based on an image of the surroundings of the information terminal 1 captured by an imaging unit included in the information terminal 1, measurement information obtained by an acceleration sensor, etc. As a result, even if the wireless connection between the information terminal 1 and the positioning device 2 has been disconnected, the information processing system S can cause the information terminal 1 to reestablish wireless connection with the positioning device 2 at a timing when the information terminal 1 has moved and its positional relationship with the positioning device 2 may have changed.

[0073] As shown in FIG. 8(b), the connection unit 131 may re-establish a wireless connection with the positioning device 2 on the condition that the information terminal 1 has not moved for a time period equal to or greater than a predetermined reference value after the wireless connection between the information terminal 1 and the positioning device 2 has been disconnected. The reference time value is a predetermined time period used as a reference for re-connection and is, for example, designated in advance by an administrator who manages multiple positioning devices 2. In this case, the connection unit 131 determines that the information terminal 1 has not moved for a time period equal to or greater than the predetermined reference value, for example, based on an image of the surroundings of the information terminal 1 captured by an imaging unit included in the information terminal 1, measurement information obtained by an acceleration sensor, etc. As a result, even if the wireless connection between the information terminal 1 and the positioning device 2 has been disconnected, the information processing system S can cause the information terminal 1 to re-establish a wireless connection with the positioning device 2 if the information terminal 1 has remained in the same place for a long time.

[0074] Furthermore, when the wireless connection between the information terminal 1 and the positioning device 2 is disconnected for a reason other than the above-described disconnection conditions under which the disconnection unit 134 disconnects the wireless connection (such as a device error), the connection unit 131 may not need to re-establish a wireless connection with the positioning device 2. This enables the information processing system S to prevent the information terminal 1 from attempting a wireless connection with the positioning device 2 in which some abnormality is occurring.

[0075] [Information processing method flow] 9, 10, and 11 are diagrams showing flowcharts of an exemplary information processing method executed by the information terminal 1 according to this embodiment. FIG. 9 shows processing in which the information terminal 1 executes a wireless connection with the positioning device 2. The connection unit 131 receives a wireless signal for short-range wireless communication from any of the positioning devices 2 (S11). The connection unit 131 identifies the received signal strength when the wireless signal for short-range wireless communication is received. If the received signal strength is less than the reference strength (NO in S12), the connection unit 131 ends the processing without establishing a wireless connection with the positioning device 2.

[0076] If the received signal strength is equal to or greater than the reference strength (YES in S12), the connection unit 131 determines whether the distance between the information terminal 1 and the first positioning device 2a is less than the first reference distance, i.e., whether there is a first positioning device 2a whose distance between the information terminal 1 and the first positioning device 2a is less than the first reference distance. If there is no first positioning device 2a whose distance between the information terminal 1 and the first positioning device 2a is less than the first reference distance (NO in S13), the connection unit 131 proceeds to step S15.

[0077] If there is a first positioning device 2a where the distance between the information terminal 1 and the first positioning device 2a is less than the first reference distance (YES in S13), the connection unit 131 determines whether the positioning device 2 (second positioning device 2b) that is currently attempting to establish a wireless connection is included in a list indicating multiple positioning devices that are pre-associated with the first positioning device 2a.

[0078] If the positioning device 2 is not included in the list (NO in S14), the connection unit 131 ends the process without establishing a wireless connection with the positioning device 2. If the positioning device 2 is included in the list (YES in S14), the connection unit 131 proceeds to step S15.

[0079] The connection unit 131 establishes a wireless connection via short-range wireless communication with the positioning device 2 (S15). The connection unit 131 receives connection information for establishing a UWB wireless connection from the positioning device 2 with which it has established a wireless connection via short-range wireless communication (S16). The connection unit 131 uses the received connection information to establish a UWB wireless connection with the positioning device 2 with which it has established a wireless connection via short-range wireless communication (S17).

[0080] 10 shows the process in which the information terminal 1 disconnects the wireless connection with the positioning device 2. While the connection unit 131 is wirelessly connected to the positioning device 2, the distance measurement unit 132 measures the distance between the information terminal 1 and the positioning device 2 that is wirelessly connected to it (S21).

[0081] If the distance between the information terminal 1 and the positioning device 2 is equal to or greater than the second reference distance (NO in S22), the disconnection unit 134 disconnects the wireless connection with the positioning device 2 (S23). If the distance between the information terminal 1 and the positioning device 2 is less than the second reference distance (YES in S22), the disconnection unit 134 determines whether the distance between the information terminal 1 and the first positioning device 2a is less than the first reference distance, i.e., whether there is a first positioning device 2a that is less than the first reference distance.

[0082] If there is no first positioning device 2a whose distance between the information terminal 1 and the first positioning device 2a is less than the first reference distance (NO in S24), the disconnection unit 134 determines whether the number of multiple positioning devices 2 to which the connection unit 131 has a wireless connection is equal to or greater than the reference number.

[0083] If the number of the positioning devices 2 wirelessly connected to the connection unit 131 is less than the reference number (NO in S25), the disconnection unit 134 maintains the wireless connection (S27). If the number of the positioning devices 2 wirelessly connected to the connection unit 131 is equal to or greater than the reference number (YES in S25), the connection unit 131 disconnects the wireless connection with one or more positioning devices 2 so that the number of the positioning devices 2 wirelessly connected to the connection unit 131 becomes less than the reference number (S23).

[0084] If there is a first positioning device 2a whose distance between the information terminal 1 and the first positioning device 2a is less than the first reference distance (YES in S24), it is determined whether the positioning device 2 (second positioning device 2b) is included in a list indicating multiple positioning devices previously associated with the first positioning device 2a. If the positioning device 2 is not included in the list (NO in S26), the disconnection unit 134 disconnects the wireless connection with the positioning device 2 (S23). If the positioning device 2 is included in the list (YES in S26), the disconnection unit 134 maintains the wireless connection (S27).

[0085] 11 shows the process of positioning performed by the information terminal 1. While the connection unit 131 is wirelessly connected to the positioning device 2, the distance measurement unit 132 measures the distance between the information terminal 1 and the wirelessly connected positioning device 2 (S31). Here, the distance measurement unit 132 may use the distance measured in step S21.

[0086] The positioning unit 135 determines whether the distance between the information terminal 1 and the first positioning device 2a is less than a first reference distance, i.e., whether there is a first positioning device 2a whose distance between the information terminal 1 and the first positioning device 2a is less than the first reference distance. If there is no first positioning device 2a whose distance between the information terminal 1 and the first positioning device 2a is less than the first reference distance (NO in S32), the positioning unit 135 executes a first positioning process to identify the position of the information terminal 1 using the positions of each of the multiple positioning devices 2 including the first positioning device 2a and the second positioning device 2b, and the distance between the information terminal 1 and each of the multiple positioning devices 2 including the first positioning device 2a and the second positioning device 2b (S33).

[0087] If there is a first positioning device 2a whose distance between the information terminal 1 and the first positioning device 2a is less than the first reference distance (YES in S32), the positioning unit 135 executes a second positioning process to determine the position of the information terminal 1 using the position of the first positioning device 2a without using the position of the second positioning device 2b (S34).

[0088] [Effects of the embodiment] According to the information processing system S of this embodiment, the information terminal 1 first establishes a wireless connection with the first positioning device 2a, and then establishes a wireless connection with the second positioning device 2b included in a list previously associated with the first positioning device 2a, thereby locating the position of the information terminal 1. In this way, the information processing system S prevents the information terminal 1 from establishing a wireless connection with a positioning device 2 that does not contribute to positioning (for example, a positioning device 2 that is far away from the information terminal 1), and makes it easier for the information terminal 1 to establish a wireless connection with a new positioning device 2, thereby enabling smooth positioning of the information terminal 1.

[0089] Furthermore, this invention will make it possible to contribute to Goal 9 of the United Nations' Sustainable Development Goals (SDGs), which is "Build resilient infrastructure, promote inclusive and sustainable industrialization, and promote innovation and resilience."

[0090] The present invention has been described above using embodiments, but the technical scope of the present invention is not limited to the scope described in the above embodiments, and various modifications and changes are possible within the scope of the gist of the present invention. For example, all or part of the device can be configured by functionally or physically distributing or integrating any unit. Furthermore, new embodiments resulting from any combination of multiple embodiments are also included in the embodiments of the present invention. The effects of the new embodiments resulting from the combination also have the effects of the original embodiments. [Explanation of symbols]

[0091] S Information Processing System 1. Information terminal 11 Communications Department 12 Storage section 13 Control Unit 131 Connection 132 Ranging section 133 Acquisition Department 134 Cutting section 135 Positioning Unit 2. Positioning Device

Claims

1. An information terminal that performs positioning by wirelessly connecting to a positioning device, a connection unit for wirelessly connecting with a plurality of positioning devices; a distance measuring unit that measures a distance between the information terminal and a target positioning device while the connection unit is wirelessly connected to the target positioning device among the plurality of positioning devices; a disconnection unit that disconnects wireless connection with at least one of the plurality of positioning devices, on condition that the distance between the information terminal and the target positioning device is less than a disconnection reference distance and the number of the plurality of positioning devices is equal to or greater than a reference number; An information terminal having the above.

2. the disconnection unit disconnects the wireless connection with the target positioning device on condition that the distance between the information terminal and the target positioning device is equal to or greater than the disconnection reference distance; The information terminal according to claim 1.

3. the disconnection unit disconnects the wireless connection with the at least one positioning device in descending order of distance from the information terminal so that the number of devices becomes less than the reference number.

3. The information terminal according to claim 1 or 2.

4. The information terminal further includes an acquisition unit that acquires a list indicating a plurality of predetermined positioning devices that are associated in advance with the target positioning device; the disconnection unit disconnects the wireless connection with at least one positioning device not included in the list among the plurality of positioning devices, on condition that the distance between the information terminal and the target positioning device is less than the disconnection reference distance.

3. The information terminal according to claim 1 or 2.

5. the connection unit establishes a wireless connection with the target positioning device on the condition that the distance between the information terminal and the target positioning device is less than a connection reference distance; the disconnection unit disconnects the wireless connection with at least one positioning device not included in the list among the plurality of positioning devices, on condition that the distance between the information terminal and the target positioning device is less than the disconnection reference distance and the distance between the information terminal and the target positioning device is less than the connection reference distance; 5. The information terminal according to claim 4.

6. An information terminal that performs positioning by wirelessly connecting to a positioning device, establishing wireless connections with a plurality of positioning devices; measuring a distance between the information terminal and a target positioning device among the plurality of positioning devices while the information terminal is wirelessly connected to the target positioning device; disconnecting the wireless connection with at least one of the plurality of positioning devices, on condition that the distance between the information terminal and the target positioning device is less than a disconnection reference distance and the number of the plurality of positioning devices is equal to or greater than a reference number; An information processing method comprising:

7. An information terminal that performs positioning by wirelessly connecting to a positioning device, establishing wireless connections with a plurality of positioning devices; measuring a distance between the information terminal and a target positioning device among the plurality of positioning devices while the information terminal is wirelessly connected to the target positioning device; disconnecting the wireless connection with at least one of the plurality of positioning devices, on condition that the distance between the information terminal and the target positioning device is less than a disconnection reference distance and the number of the plurality of positioning devices is equal to or greater than a reference number; A program that executes.

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