Position detection system and position detection method

Abstract

To detect a position of a moving body in a region including a building efficiently with high accuracy.SOLUTION: The present invention comprises: a speaker 4 installed in an area; a storage unit 31 in which a magnetic field map MG indicating a distribution of magnetic fields in the area is stored; a terminal information acquisition unit 33 for acquiring information transmitted from a moving body terminal 2 held or mounted to a moving body M; and a position detection unit 35 for detecting a position of the moving body. The speaker emits sound based on an acoustic signal including an assigned identification information, the terminal information acquisition unit is capable of acquiring identification related information, magnetic field information measured by the moving body terminal, and movement amount information indicating a movement amount of the moving body terminal when having acquired the acoustic signal emitted from the speaker, and the position detection unit sets the position of the speaker having emitted sound including identification information acquired by the moving body terminal as an initial position on the basis of the identification related information, and detects the position of the moving body terminal on the basis of magnetic field information, movement amount information indicating the movement amount of the moving body terminal from the initial position, and the distribution of magnetic fields.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a position detection system and a position detection method. [Background technology]

[0002] GPS (Global Positioning System) is used to detect the positions of moving objects such as people, vehicles, and robots. However, GPS cannot receive GPS signals in areas including buildings (e.g., indoors), and cannot effectively detect positions. Therefore, a technology has been proposed that uses a magnetic field map to detect the position of a moving object indoors. For example, Patent Document 1 discloses a configuration in which a reference magnetism is measured in a space (environment) in which a mobile body moves, a magnetic field map (magnetic-position information) in which the reference magnetism corresponds to the position where the reference magnetism is measured is stored in advance, an actual measured magnetism is measured using a magnetic sensor equipped on the mobile body, and the reference magnetism in the magnetic field map is compared with the measured actual magnetism to identify the position where the actual measured magnetism was measured. However, in the configuration disclosed in Patent Document 1, for example, there may be a plurality of locations with the same amount of reference magnetism in an area shown in a magnetic field map. Therefore, simply comparing the reference magnetism in the magnetic field map with the measured magnetic field may result in a plurality of candidates for the location where the measured magnetic field is measured, and the identified location may differ from the actual location, or it may take a long time to identify the location. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2009-289145 A Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide a position detection system and a position detection method that are capable of detecting the position of a moving object in an area including a building (for example, indoors) with high accuracy and efficiency. [Means for solving the problem]

[0005] In order to solve the above problems, the present invention employs the following means. That is, the position detection system of the present invention is a position detection system that detects the position of a mobile body in an area including a building, and includes a speaker provided in an area set in the area including the building, a memory unit that stores a magnetic field map showing the distribution of magnetic fields in the area in which the speaker is provided, a terminal information acquisition unit that acquires information transmitted from a mobile terminal carried or attached to the mobile body, and a position detection unit that detects the position of the mobile body in the area, wherein the speaker emits a sound based on an acoustic signal including identification information assigned to the speaker, and the terminal information acquisition unit receives the acoustic signal emitted from the speaker at the mobile terminal. The position detection unit is capable of acquiring identification-related information regarding the identification information contained in a sound based on a signal, magnetic field information regarding a magnetic field measured by the mobile terminal, and movement amount information indicating the amount of movement of the mobile terminal, and the position detection unit sets the position of the speaker that emitted the sound including the identification information acquired by the mobile terminal as an initial position based on the identification-related information, acquires the magnetic field map of the area in which the speaker is installed from the memory unit, and detects the position of the mobile terminal in the area based on the magnetic field information, the movement amount information indicating the amount of movement of the mobile terminal from the initial position, and the distribution of the magnetic field in the magnetic field map.

[0006] According to such a configuration, a speaker provided in an area set in a region (e.g., indoors) including a building emits a sound based on an acoustic signal including identification information assigned to the speaker. When a mobile terminal carried or attached to a mobile body acquires a sound emitted from the speaker, the terminal information acquisition unit acquires identification-related information regarding the identification information included in the acquired sound. The position detection unit sets the position of the speaker that emitted the sound including the identification information acquired by the mobile terminal as an initial position based on the identification-related information. The position detection unit also acquires from the storage unit a magnetic field map of the area in which the speaker set as the initial position is provided. The position detection unit detects the position of the mobile terminal in the area based on the magnetic field information related to the magnetic field measured by the mobile terminal acquired by the terminal information acquisition unit, the movement amount information indicating the movement amount of the mobile terminal from the initial position, and the distribution of the magnetic field in the magnetic field map of the area in which the speaker is provided. In this way, by comparing the movement amount of the mobile terminal from the initial position set at the position in which the speaker is provided and the magnetic field information related to the magnetic field measured by the mobile terminal with the distribution of the magnetic field in the magnetic field map, the position of the mobile terminal can be easily specified even if there are multiple positions with the same magnetic field amount in the area. Therefore, it is possible to perform the position detection of the mobile terminal in an area including a building with high accuracy and efficiency.

[0007] In one aspect of the present invention, the position detection system of the present invention has a plurality of speakers spaced apart at entrances and exits to the area in the direction of entry and exit, and the position detection unit determines the direction of movement of the mobile terminal relative to the area based on the order in which the identification information contained in the sound emitted from the plurality of speakers is acquired.

[0008] According to this configuration, by providing a plurality of speakers at the entrances and exits of the area at intervals in the direction of entering and exiting the area, the moving direction of the mobile terminal relative to the area can be easily identified based on the acquisition order of the identification information contained in the sounds emitted from the plurality of speakers. This makes it possible to detect whether the mobile terminal is attempting to enter the area from the outside or to exit the area from the inside.

[0009] The position detection method of the present invention is a position detection method that detects the position of a mobile body in an area including a building using a speaker provided in an area set in the area including the building and a magnetic field map showing the distribution of a magnetic field in the area, and is characterized in that when a sound based on an acoustic signal including identification information assigned to the speaker emitted from the speaker is acquired by a mobile terminal carried or attached to the mobile body, identification-related information related to the identification information contained in the sound is acquired from the mobile terminal, and based on the received identification-related information, the position of the speaker that emitted the sound including the identification information acquired by the mobile terminal is set as an initial position, the magnetic field map of the area in which the speaker is provided is acquired, magnetic field information related to the magnetic field measured by the mobile terminal and movement amount information showing the movement amount of the mobile terminal from the initial position are acquired from the mobile terminal, and the position of the mobile terminal in the area is detected based on the magnetic field information, the movement amount information, and the distribution of the magnetic field in the magnetic field map.

[0010] According to this configuration, when a mobile terminal acquires a sound emitted from a speaker installed in an area set in a region including a building, the position of the speaker that has acquired the sound including the identification information and that has been acquired by the mobile terminal is set as an initial position based on the identification information included in the acquired sound. Furthermore, the position of the mobile terminal in the area is detected based on magnetic field information related to the magnetic field measured by the mobile terminal, movement amount information indicating the amount of movement of the mobile terminal from the initial position, and the magnetic field distribution in the magnetic field map of the area in which the speaker is installed. In this way, by comparing the amount of movement of the mobile terminal from the initial position set at the position where the speaker is installed and the magnetic field information related to the magnetic field measured by the mobile terminal with the distribution of the magnetic field in the magnetic field map, the position of the mobile terminal can be easily identified even if there are multiple positions with the same magnetic field within the area. Therefore, it is possible to detect the position of a mobile terminal in an area including buildings with high accuracy and efficiency. Effect of the Invention

[0011] According to the present invention, it is possible to detect the position of a moving object in an area including a building (for example, indoors) with high accuracy and efficiency. [Brief description of the drawings]

[0012] [Figure 1] 1 is a block diagram showing a configuration of a position detection system according to an embodiment of the present invention. [Diagram 2] 2 is a diagram showing an example of an area in which the position detection system of FIG. 1 detects the position of a moving object; FIG. [Diagram 3] 3A and 3B are diagrams illustrating an example of speaker installation in the present embodiment. [Figure 4] 1A and 1B are diagrams showing an example of a magnetic field map and a layout map. [Diagram 5] 4 is a flowchart showing the flow of a method for setting a sound pressure distribution in a speaker in the present embodiment. [Figure 6] FIG. 13 is a diagram showing an example of sound pressure distribution actually measured in an area. [Figure 7] FIG. 7 is a diagram showing an example of a sound pressure distribution obtained by correcting the sound pressure distribution shown in FIG. 6 based on a threshold value. [Figure 8] 4 is a flowchart showing the flow of a position detection method in the present embodiment. [Figure 9] 13 is a diagram showing an example of speaker installation in a modified example of the present embodiment. FIG. [Figure 10] 13 is a diagram showing an example of speaker installation in another modified example of the present embodiment. FIG. [Figure 11]FIG. 11 is a diagram showing an example of an area in which the position of a moving object is detected in a modified example of the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of a position detection system and a position detection method according to the present invention will be described with reference to the accompanying drawings. A block diagram showing the configuration of a position detection system according to an embodiment of the present invention is shown in Fig. 1. Fig. 2 is a diagram showing an example of an area in which the position detection system of Fig. 1 detects the position of a moving object. As shown in Fig. 1, the position detection system 1 mainly includes a speaker 4, a mobile terminal 2, and a system main body 3. This position detection system 1 detects the position of a mobile object M (see Fig. 3) by detecting the position of the mobile terminal 2 indoors in buildings for various purposes such as hospitals, hotels, commercial facilities, etc. The mobile object M is, for example, a person. In this embodiment, the position detection system 1 is used, for example, by the mobile object M (person) to recognize its own position indoors.

[0014] As shown in FIG. 2, the speaker 4 is installed in a predefined area A indoors. In this embodiment, the area A is set not only indoors but also in an area including a building, for example, in an area connecting buildings on the same premises (for example, a courtyard, a connecting passage, etc.). In this embodiment, a plurality of areas A are set indoors. For example, the plurality of areas A are set on each floor of a building. Furthermore, the plurality of areas A may be set in each room provided on each floor, or a plurality of areas A may be set in one room. In this embodiment, a plurality of areas A (A1, A2) are set in each of two rooms 12A, 12B that can be accessed via a passage 11. The speakers 4 are provided at an entrance 13A to the room 12A and at an entrance 13B to the room 12B via the passage 11, respectively. Two speakers 4 are provided at each of the entrances 13A and 13B, spaced apart from each other along the entrance / exit direction of the rooms 12A and 12B at the entrances 13A and 13B. That is, a first speaker 4A and a second speaker 4B are provided at the entrance 13A, spaced apart from each other along the entrance / exit direction. A third speaker 4C and a fourth speaker 4D are provided at the entrance 13B, spaced apart from each other along the entrance / exit direction.

[0015] FIG. 3 is a diagram showing an example of speaker installation in this embodiment. As shown in Fig. 3, in this embodiment, the speakers 4 (4A to 4D) are provided on the ceiling 15 of the entrances 13A and 13B. The speakers 4 are embedded in the ceiling 15 and installed so as to emit sound toward the indoor space below the ceiling 15. The speakers 4 are electrically connected to a signal output unit 41 and an amplifier 42. The signal output unit 41 and the amplifier 42 are disposed in the attic between the ceiling 15 and the slab 16A of the upper floor. The signal output unit 41 outputs a sound signal generated by the speaker 4 to the speaker 4. The amplifier 42 amplifies the sound signal output from the signal output unit 41 and transmits it to the speaker 4. The speaker 4 emits a sound based on the sound signal output from the signal output unit 41 toward the indoor space.

[0016] The signal output unit 41 outputs an audio signal including identification information that is individually assigned to the speaker 4 in advance. Here, the audio signal may include a signal in an audible range (e.g., 20 to 20,000 Hz) or may be a signal in an inaudible range (e.g., 20,000 Hz or higher). The identification information is a signal in an inaudible range. The identification information is a so-called audio watermark signal. The identification information has, for example, a predetermined waveform. The identification information is superimposed on, for example, BGM (background music) or a signal in an audible range for indoor broadcasting. Note that the audio signal may include only the signal of the identification information and not include other signals in an audible range.

[0017] The sound pressure distribution of each speaker 4 is set in advance so that the sound based on the acoustic signal including the identification information is emitted so as to cover a predetermined range X based on the speaker 4. Each speaker 4 is set so that the sound of a sound pressure level that can be acquired by a sound acquisition unit 21 of the mobile terminal 2 described later can cover a range, for example, of a radius of about 1 to 3 m including the position directly below the speaker 4. More specifically, the sound pressure distribution of each speaker 4 is set so that the sound acquisition unit 21 can acquire the sound emitted from the speaker 4 at a height H from the floor 17 where a person who is the mobile body M is likely to carry the mobile terminal 2. For example, it is preferable to set the sound pressure distribution so that the sound pressure of the sound emitted from the speaker 4 is equal to or higher than a preset threshold (for example, 50 dB) within the predetermined range X and is less than the threshold outside the predetermined range X. Here, if the sound pressure of the sound emitted from the speaker 4 exceeds, for example, 80 dB, it may adversely affect human hearing, etc. For this reason, it is preferable to set the sound pressure distribution so that the maximum value of the sound pressure is 80 dB or less. Also, it is preferable to set the sound pressure distribution so that within a predetermined range X, the sound pressure of the sound emitted from the speaker 4 is equal to or greater than a preset threshold value (for example, 50 dB), and outside the predetermined range X, it is less than the threshold value.

[0018] The mobile terminal 2 is carried or attached to a mobile body M. The mobile terminal 2 is a terminal having portability. In this embodiment, the mobile terminal 2 is, for example, a smartphone carried by a person as the mobile body M. The mobile terminal 2 is not limited to a smartphone, and may be a tablet terminal or the like. As shown in FIG. 1, the mobile terminal 2 includes a sound acquisition unit 21, a magnetic field measurement unit 22, a movement amount measurement unit 23, and an information transmission unit 25. The sound acquisition unit 21 acquires a sound outside the mobile terminal 2. The sound acquisition unit 21 is a microphone provided in the smartphone. The sound acquisition unit 21 acquires a sound emitted by the speaker 4. The sound acquisition unit 21 analyzes the waveform of the sound emitted by the speaker 4 and determines whether or not identification information is included. When the sound acquisition unit 21 detects that identification information is included, it generates identification-related information regarding the identification information included in the acquired sound. The identification-related information regarding the identification information may be the identification information itself, or may be information for identifying the speaker 4 that is associated in advance with the identification information, information indicating the position of the speaker 4, or the like. When the identification information is detected, the identification-related information includes time information at which the sound including the identification information was acquired.

[0019] The magnetic field measuring unit 22 measures a magnetic field and generates magnetic field information related to the measured magnetic field. The magnetic field measuring unit 22 is built into the smartphone and includes a magnetic sensor (geomagnetic sensor) that measures a magnetic field. The movement amount measuring unit 23 measures the movement amount of the mobile terminal 2. The movement amount measuring unit 23 includes, for example, an acceleration sensor (not shown) built into the smartphone, and a calculation unit (not shown) that calculates the movement amount by integrating the acceleration detected by the acceleration sensor. When the sound acquisition unit 21 detects identification information, the movement amount measuring unit 23 measures the movement amount from the position of the mobile terminal 2 at the time when the identification information was detected. The information transmitting unit 25 transmits, to the system main body 3, identification-related information relating to the identification information included in the sound acquired by the sound acquiring unit 21, magnetic field information relating to the magnetic field measured by the magnetic field measuring unit 22, and movement amount information relating to the movement amount measured by the movement amount measuring unit 23. The information transmitting unit 25 transmits information to the system main body 3 via, for example, a wireless LAN (Local Area Network) such as Wi-Fi, wireless communication such as Bluetooth (registered trademark), or a network capable of transferring data such as a mobile phone communication network.

[0020] In this embodiment, the mobile terminal 2 includes an information receiving unit 26 and an information output unit 5. The information receiving section 26 receives information about the area A including the position of the mobile terminal 2 detected by a position detecting section 35 (to be described later) from the system main body 3 via the network. The information output unit 5 outputs information about the area A including the position of the mobile terminal 2 to the outside based on the information received by the information receiving unit 26. In this embodiment, the information output unit 5 is a display monitor provided in the smartphone. The information output unit 5 displays information about the area A including the position of the mobile terminal 2.

[0021] The system main body 3 is a server (physical server) equipped with a processor, memory, etc. capable of communicating with the mobile terminal 2, or a virtual server composed of a plurality of servers capable of communicating with each other via a network. The system main body 3 functionally comprises a storage unit 31, a terminal information acquisition unit 33, a position detection unit 35, and an information transmission unit 37. FIG. 4 is a diagram showing an example of a magnetic field map and a layout map. 4, the storage unit 31 stores a magnetic field map MG indicating the distribution of the magnetic field in the area A (e.g., area A1) in which the speaker 4 is provided, and a layout map ML indicating the layout of the walls 18, entrances 13A, 13B, etc. of the area A. The magnetic field map MG indicates the distribution of the magnetic field formed by the geomagnetism in the area A being affected by metal members such as steel frames arranged in the area A.

[0022] 1 acquires information transmitted from the information transmission unit 25 of the mobile terminal 2. The terminal information acquisition unit 33 acquires identification-related information related to identification information that is generated when the sound acquisition unit 21 of the mobile terminal 2 acquires a sound based on an acoustic signal emitted from the speaker 4. The terminal information acquisition unit 33 also acquires magnetic field information related to a magnetic field measured by the magnetic field measurement unit 22 of the mobile terminal 2. Furthermore, the terminal information acquisition unit 33 acquires movement amount information indicating the movement amount measured by the movement amount measurement unit 23 of the mobile terminal 2.

[0023] The position detection unit 35 identifies the speaker 4 that emitted the sound including the identification information acquired by the mobile terminal 2, based on the identification-related information acquired by the terminal information acquisition unit 33. The position detection unit 35 sets the identified position of the speaker 4 as the initial position of the mobile terminal 2 in the area A in which the speaker 4 is provided. When the position detection unit 35 identifies the speaker 4 that emitted the sound including the identification information, it acquires from the storage unit 31 the magnetic field map MG and the layout map ML of the area A in which the speaker 4 is provided. Furthermore, the position detection unit 35 acquires the amount of movement from the set initial position based on the movement amount information acquired by the terminal information acquisition unit 33. The position detection unit 35 compares the acquired magnetic field information and the amount of movement of the mobile terminal 2 from the initial position with the distribution of the magnetic field in the magnetic field map MG. The position detection unit 35 identifies the position coordinates where the amount of movement (distance) from the initial position and the acquired magnetic field information match the magnetic field registered in advance in the distribution of the magnetic field in the magnetic field map MG. In this way, the position detection unit 35 detects the position of the mobile terminal 2 in area A.

[0024] Furthermore, the position detection unit 35 specifies the acquisition order of the identification information included in the sounds emitted from the multiple speakers 4 based on time information included in the identification-related information related to the identification information generated when the sound based on the acoustic signal emitted from the speaker 4 is acquired. The position detection unit 35 determines the moving direction of the mobile terminal 2 at, for example, the entrances 13A and 13B based on the specified acquisition order. For example, at the entrance 13A, the position detection unit 35 acquires time information at which the identification information included in the sound emitted from the first speaker 4A was detected and time information at which the identification information included in the sound emitted from the second speaker 4B was detected. When the position detection unit 35 detects the identification information included in the sound emitted from the second speaker 4B after detecting the identification information included in the sound emitted from the first speaker 4A, it determines that the mobile terminal 2 is attempting to enter the area A1 from the outside to the inside at the entrance 13A. When the position detection unit 35 detects identification information contained in the sound emitted by the second speaker 4B and then detects identification information contained in the sound emitted by the first speaker 4A, it determines that the mobile terminal 2 is attempting to exit from the inside of area A1 to the outside at the entrance / exit 13A. In this manner, when the mobile terminal 2 is about to enter area A (A1, A2), the position detection unit 35 detects the position of the mobile terminal 2 in area A that the mobile terminal 2 is about to enter. Information about area A including the position of the mobile terminal 2 detected by the position detection unit 35 is transmitted from the information transmission unit 37 of the system main body 3 to the information reception unit 26 of the mobile terminal 2 via the network.

[0025] In the position detection system 1, before detecting the position of the mobile terminal 2, it is necessary to set the sound pressure distribution in each speaker 4 and generate a magnetic field map in each area A. Fig. 5 is a flowchart showing the flow of a method for setting the sound pressure distribution in the speaker in this embodiment. Fig. 6 is a diagram showing an example of the sound pressure distribution actually measured in an area. First, as shown in FIG. 3, the sound pressure distribution is obtained at each speaker 4 at a height H (for example, H=1.2 m: see FIG. 3) from the floor 17 where the mobile terminal 2 is expected to be used (step S1). For this purpose, for example, a calculation based on the directional characteristics of the speaker 4 is performed to obtain the sound pressure distribution. Alternatively, sound may be actually emitted from the speaker 4 and the sound pressure distribution may be measured. In this case, as shown in FIG. 6, the sound pressure level at a position of height H=1.2 m directly below the speaker 4 is standardized as 0 dB. Then, a horizontal plane of height H=1.2 m is divided into a plurality of cells C, each 50 cm square, for example, and the extent to which the sound pressure level in each cell C attenuates relative to the sound pressure level (0 dB) in the cell C0 directly below the speaker 4 is measured. At this time, at a position horizontally distant from the cell directly below the speaker 4 by a certain amount or more, the sound pressure level may be measured only in every other cell, thereby saving the time required for measuring the sound pressure level.

[0026] Next, a range X is set within which the identification information contained in the sound emitted by each speaker 4 can be detected by the mobile terminal 2 (step S2). This range X can be set, for example, inside a circle centered on a position directly below the speaker 4. This range X can be set, for example, to match the width of the entrances 13A and 13B. Furthermore, a threshold for detecting a sound including identification information within range X is set (step S3). For example, in the case where the mobile terminal 2 detects a sound including identification information when the sound pressure level is 50 dB or more, the threshold is set to 50 dB.

[0027] FIG. 7 is a diagram showing an example of a sound pressure distribution obtained by correcting the sound pressure distribution shown in FIG. 6 based on a threshold value. Next, the sound pressure distribution acquired in step S1 is corrected based on the threshold value set in step S3 (step S4). That is, as shown in FIG. 7, the sound pressure distribution is adjusted so that the sound pressure levels of all cells C located within range X are equal to or higher than the threshold value (50 dB) and the sound pressure levels of cells C located outside range X are less than the threshold value (50 dB). As a result, the sound pressure level in cell C0 located directly below speaker 4 is, for example, 63 dB. That is, the output value from speaker 4 is determined so that the sound pressure level in cell C0 directly below speaker 4 becomes 63 dB after correction from the reference value 0 dB (step S5).

[0028] In addition, to generate a magnetic field map of each area A as shown in Figure 4, existing technologies can be used as appropriate, such as arranging multiple magnetic sensors at intervals in a direction parallel to the floor surface and moving (scanning) these multiple magnetic sensors in a direction parallel to the floor surface and perpendicular to the above-mentioned direction. 4 is thereby generated for each area A. The generated magnetic field map MG is stored in the storage unit 31 in association with the area A.

[0029] FIG. 8 is a flowchart showing the flow of the position detection method in this embodiment. As shown in FIG. 8, in the system main body 3, the terminal information acquisition unit 33 determines at a preset time interval whether or not it has received identification-related information transmitted when a sound including identification information is acquired from the mobile terminal 2 (step S11). As a result, if the identification related information has not been received, the process returns to step S11, and the same process is repeatedly executed at predetermined time intervals. When the identification related information is received in step S11, the system main body 3 then checks whether or not it has received identification related information indicating that it has acquired identification information from two speakers 4 within a certain period of time (step S12). For example, when a user passes through the entrance / exit 13A, the system main body 3 sequentially acquires sounds emitted from the first speaker 4A and the second speaker 4B, and therefore receives two pieces of identification related information indicating that it has acquired identification information from the two speakers 4. In this case, the process proceeds to step S13. On the other hand, for example, when a user passes by crossing the vicinity of the entrance / exit 13A, the identification information included in the sound emitted from only one of the first speaker 4A and the second speaker 4B may be acquired. In this case, the system main body 3 receives only once the identification-related information indicating that the identification information has been acquired from only one speaker 4. In this case (No in step S12), the process returns to step S11.

[0030] When the system main body 3 receives two pieces of identification-related information indicating that identification information has been acquired from the two speakers 4 (Yes in step S12), it judges the moving direction of the mobile terminal 2 at the entrances 13A and 13B where the speakers 4 are provided (step S13). Specifically, it is judged at the entrances 13A and 13B whether the moving direction of the mobile terminal 2 is the direction of entering the areas A1 and A2. To do this, the order in which sounds including the identification information were acquired by the two speakers 4 provided at the entrances 13A and 13B is specified based on time information associated with the two pieces of identification-related information acquired within a certain period of time. For example, when the terminal information acquisition unit 33 acquires a sound including identification information from the first speaker 4A at the entrance 13A and then acquires a sound including identification information from the second speaker 4B, the terminal information acquisition unit 33 determines that the mobile terminal 2 is moving in a direction to enter the area A1. When the terminal information acquisition unit 33 acquires a sound including identification information from the second speaker 4B at the entrance 13A and then acquires a sound including identification information from the first speaker 4A, the terminal information acquisition unit 33 determines that the mobile terminal 2 is moving in a direction to exit the area A1. When the terminal information acquisition unit 33 acquires a sound including identification information from the third speaker 4C at the entrance 13B and then acquires a sound including identification information from the fourth speaker 4D, the terminal information acquisition unit 33 determines that the mobile terminal 2 is moving in a direction to enter the area A2. Furthermore, if the terminal information acquisition unit 33 acquires a sound including identification information from the fourth speaker 4D at the entrance / exit 13B and then acquires a sound including identification information from the third speaker 4C, it determines that the mobile terminal 2 is moving in the direction of exiting the area A2.

[0031] If it is determined in step S13 that the mobile terminal 2 is moving in the direction of entering area A1 or area A2, the system main body 3 obtains the layout map ML from the memory unit 31 along with the magnetic field map MG of the destination areas A1 and A2 (step S14). Then, the position detection unit 35 sets the position directly below the speaker 4 (for example, the second speaker 4B or the fourth speaker 4D) that emitted the sound including the identification information as the initial position in the areas A1 and A2 (step S15). Thereafter, in the system main body 3, the process proceeds to position detection processing S20 in which the position detection section 35 detects the position of the mobile terminal 2, which will be described later in detail.

[0032] Also, in step S13, if it is determined that the mobile terminal 2 is moving in a direction to leave the area A1 or area A2 (No in step S13), the terminal information acquisition unit 33 checks whether or not there is an area where the magnetic field map MG is set in the area to which the mobile terminal 2 has left the area A1 or area A2 (step S16). If there is no area set in the area to which the mobile terminal 2 has left the area, the process returns to step S11 and repeats the process. On the other hand, if the exit destination is an area where the magnetic field map MG is set, the system main body 3 acquires the layout map ML together with the magnetic field map MG of the exit destination area A from the storage unit 31 (step S17). Furthermore, the position detection unit 35 sets the position directly below the speaker 4 (for example, the first speaker 4A or the third speaker 4C) that emitted the sound including the identification information as the initial position in the exit destination area A (step S18). Thereafter, in the system main body 3, the process proceeds to position detection processing S20 in which the position detection section 35 detects the position of the mobile terminal 2.

[0033] In the position detection process S20, magnetic field information measured by the magnetic field measurement unit 22 of the mobile terminal 2 and movement amount information measured by the movement amount measurement unit 23 are received (acquired) (step S21). Furthermore, the system main body 3 acquires the amount of movement from the initial position at every preset time interval based on the movement amount information acquired in step S21. Furthermore, the system main body 3 detects the position of the mobile terminal 2 in areas A1 and A2 by comparing the acquired amount of movement from the initial position and the magnetic field information with the magnetic distribution in the magnetic field map MG acquired in steps S14 and S17 (step S22). Furthermore, the system main body 3 outputs information about area A including the position of the mobile terminal 2 detected in step S22 to the outside (step S23). For example, the system main body 3 transmits image information indicating the position of the mobile terminal 2 in the layout map ML of areas A1 and A2 in which the mobile terminal 2 is located, from the information transmitting unit 37 of the system main body 3 to the information receiving unit 26 of the mobile terminal 2, as information about area A including the position of the mobile terminal 2. Based on the information received from the system main body 3, the information output unit 5 of the mobile terminal 2 displays the position of the mobile terminal 2 in the layout map ML of areas A1 and A2 in which the mobile terminal 2 is located, as information about area A including the position of the mobile terminal 2. This allows the mobile unit M, who is the user of the mobile terminal 2, to recognize its own position in area A.

[0034] The position detection system 1 as described above is a position detection system 1 that detects the position of a moving body M in an area including a building, and includes a speaker 4 provided in an area A set in the area including the building, a memory unit 31 that stores a magnetic field map MG that indicates the distribution of the magnetic field in the area A in which the speaker 4 is provided, a terminal information acquisition unit 33 that acquires information transmitted from a mobile terminal 2 carried or attached to the moving body M, and a position detection unit 35 that detects the position of the moving body M in the area A, the speaker 4 emits a sound based on an acoustic signal including identification information assigned to the speaker 4, and the terminal information acquisition unit 33 receives the sound emitted from the speaker 4 at the mobile terminal 2 and detects the position of the moving body M in the area A. When a sound based on the acoustic signal is acquired, the position detection unit 35 can acquire identification-related information related to the identification information contained in the acquired sound, magnetic field information related to the magnetic field measured by the mobile terminal 2, and movement amount information indicating the amount of movement of the mobile terminal 2.The position detection unit 35 sets the position of the speaker 4 that emitted the sound including the identification information acquired by the mobile terminal 2 as an initial position based on the identification-related information, acquires a magnetic field map MG of the area A in which the speaker 4 is provided from the memory unit 31, and detects the position of the mobile terminal 2 in the area A based on the magnetic field information, the movement amount information indicating the amount of movement of the mobile terminal 2 from the initial position, and the distribution of the magnetic field in the magnetic field map MG. According to this configuration, speaker 4 provided in area A set in an area including a building emits sound based on an acoustic signal including identification information assigned to speaker 4. When a mobile terminal 2 carried or attached to mobile body M acquires a sound emitted from speaker 4, terminal information acquisition unit 33 acquires identification-related information regarding the identification information included in the acquired sound. Position detection unit 35 sets the position of speaker 4 that has emitted the sound including the identification information, acquired by mobile terminal 2, as an initial position based on the identification-related information. The position detection unit 35 also acquires from the storage unit 31 the magnetic field map MG of the area A in which the speaker 4 set as the initial position is provided. The position detection unit 35 detects the position of the mobile terminal 2 in the area A based on the magnetic field information related to the magnetic field measured by the mobile terminal 2 acquired by the terminal information acquisition unit 33, the movement amount information indicating the movement amount of the mobile terminal 2 from the initial position, and the distribution of the magnetic field in the magnetic field map MG of the area A in which the speaker 4 is provided. In this way, by comparing the movement amount of the mobile terminal 2 from the initial position set at the position where the speaker 4 is provided and the magnetic field information related to the magnetic field measured by the mobile terminal 2 with the distribution of the magnetic field in the magnetic field map MG, the position of the mobile terminal 2 can be easily specified even if there are multiple positions with the same magnetic field amount in the area A. Therefore, it is possible to perform the position detection of the mobile terminal M in an area including a building (for example, indoors) with high accuracy and efficiency.

[0035] In addition, in the position detection system 1, speakers 4 are installed at multiple positions in an area including a building, and the position detection unit 35 identifies the speaker 4 that emitted a sound including identification information acquired by the mobile terminal 2 based on the identification-related information acquired by the terminal information acquisition unit 33, and sets the position of the identified speaker 4 as the initial position. According to this configuration, when speakers 4 are provided at multiple positions, it is possible to identify the speaker 4 from which the mobile terminal 2 has acquired sound, based on the identification information included in the sound emitted from the speaker 4. As a result, by setting the position of the identified speaker 4 as the initial position, it is possible to perform highly accurate and efficient position detection of the mobile terminal 2 in area A where multiple speakers 4 are provided.

[0036] The mobile terminal 2 also includes a sound acquisition unit 21 that acquires sound including identification information emitted from the speaker 4, a magnetic field measurement unit 22 that measures a magnetic field, a movement amount measurement unit 23 that measures the movement amount of the mobile terminal 2, and an information transmission unit 25 that transmits identification-related information regarding the identification information contained in the sound acquired by the sound acquisition unit 21, magnetic field information regarding the magnetic field measured by the magnetic field measurement unit 22, and movement amount information regarding the movement amount measured by the movement amount measurement unit 23. According to this configuration, the mobile terminal 2 including the sound acquisition unit 21, the magnetic field measurement unit 22, the movement amount measurement unit 23, and the information transmission unit 25 can be carried or attached to the mobile body M, thereby enabling the position of the mobile terminal 2 to be detected with high accuracy and efficiency. As such a mobile terminal 2, for example, an existing portable communication terminal such as a smartphone can be used.

[0037] Moreover, the position detection system 1 further includes an information output unit 5 that outputs information about the area A including the position of the mobile terminal 2 detected by the position detection unit 35 to the outside. According to this configuration, by outputting information regarding area A, including the position of mobile terminal 2 detected by position detection unit 35, to the outside, it is possible to easily grasp the position of mobile terminal 2 in area A, i.e., the position of mobile unit M.

[0038] In addition, the position detection system 1 has multiple speakers 4 spaced apart at the entrances and exits of area A in the direction of entering and exiting area A, and the position detection unit 35 determines the direction of movement of the mobile terminal 2 relative to area A based on the order of acquisition of identification information contained in the sounds emitted from the multiple speakers 4. According to this configuration, by providing a plurality of speakers 4 at the entrance / exit of area A at intervals in the direction of entering / exiting area A, it is possible to easily identify the moving direction of the mobile terminal 2 relative to area A based on the acquisition order of the identification information included in the sounds emitted from the plurality of speakers 4. This makes it possible to detect whether the mobile terminal M is attempting to enter area A from the outside into area A or to exit area A from the inside to the outside.

[0039] The position detection method as described above is a position detection method that detects the position of a mobile body in an area including a building using a speaker 4 provided in area A set in the area including the building and a magnetic field map MG that shows the distribution of the magnetic field in area A. When a sound based on an acoustic signal including identification information assigned to the speaker 4 is acquired by a mobile terminal 2 carried or attached to the mobile body M, identification-related information regarding the identification information contained in the sound is acquired from the mobile terminal 2, and based on the received identification-related information, the position of the speaker 4 that emitted the sound including the identification information acquired by the mobile terminal 2 is set as an initial position, a magnetic field map MG of area A in which the speaker 4 is provided is acquired, magnetic field information regarding the magnetic field measured by the mobile terminal 2 and movement amount information indicating the movement amount of the mobile terminal 2 from the initial position are acquired from the mobile terminal 2, and the position of the mobile terminal 2 in area A is detected based on the magnetic field information, the movement amount information, and the distribution of the magnetic field in the magnetic field map MG. According to this configuration, when a mobile terminal 2 acquires a sound emitted from a speaker 4 provided in area A set in an area including a building, the position of the speaker 4 that emitted the sound including the identification information acquired by the mobile terminal 2 is set as the initial position based on the identification information contained in the acquired sound. Furthermore, the position of the mobile terminal 2 in area A is detected based on magnetic field information regarding the magnetic field measured by the mobile terminal 2, movement amount information indicating the amount of movement of the mobile terminal 2 from the initial position, and the distribution of the magnetic field in the magnetic field map MG of area A in which the speaker 4 is provided. In this way, by comparing the amount of movement of the mobile terminal 2 from the initial position set at the position where the speaker 4 is provided and the magnetic field information related to the magnetic field measured by the mobile terminal 2 with the distribution of the magnetic field in the magnetic field map MG, the position of the mobile terminal 2 can be easily identified even if there are multiple positions with the same magnetic field amount within the area A. Therefore, it is possible to detect the position of the mobile terminal M in an area including a building (for example, indoors) with high accuracy and efficiency.

[0040] (Modification of the embodiment) The position detection system and the position detection method of the present invention are not limited to the above-described embodiment explained with reference to the drawings, and various modifications are possible within the technical scope thereof. For example, in the above embodiment, the speaker 4 is provided on the ceiling 15, but this is not limiting. For example, as shown in Fig. 9, the speaker 4 may be embedded in the floor 17. In this case, the signal output unit 41 and the amplifier 42 are disposed under the floor between the floor 17 and the slab 16B of the floor. 10, the speaker 4 may be embedded in the wall 18. In this case, the speaker 4 emits sound in the horizontal direction. In this case, the signal output unit 41 and the amplifier 42 are disposed inside the wall 18.

[0041] In addition, in the above embodiment, two speakers 4 are provided at each of the entrances 13A and 13B, but the entrances 13A and 13B may be stairs, corridors (including connecting corridors), elevator entrances, etc. that provide access to the areas A1 and A2. Furthermore, when entering or exiting from a passage 11 whose movement is fixed to one direction, such as an escalator going from area A2 to area A1, the movement direction of the mobile terminal 2 of the mobile object M is fixed to one direction as shown in Fig. 11. In such a case, instead of providing two speakers 4A, 4B, 4C, and 4D in areas A1 and A2, respectively, as in Fig. 2, the initial position may be set based on a recognition signal included in a sound emitted from only one speaker 4. In addition, examples of passageways 11 shown in FIG. 11 where movement is restricted to one direction include, in addition to escalators, immigration routes at airports, routes at exhibition facilities, routes at amusement parks, or places where movement is restricted to one direction such as walking sidewalks, or emergency exits used only in the event of an evacuation.

[0042] In addition, in the above embodiment, a plurality of speakers 4 are provided in a plurality of areas A, but this is not limited to the above. For example, even if one speaker 4 is provided in only one area A, it is possible to detect the position of the mobile terminal 2 in the area A by using the position of the speaker 4 as the initial position. In the above embodiment, a person is exemplified as the moving body M, but the moving body M is not limited to this. For example, the moving body M may be a pet (animal) or the like. The moving body M may also be a robot, a vehicle, or the like that is capable of moving in an area including a building. When the mobile unit M is a robot, a vehicle, or the like, the movement amount measurement unit 23 that measures the movement amount of the mobile terminal 2 may use an encoder that detects the amount of rotation of a wheel provided on the robot or vehicle.

[0043] In the above embodiment, the position detection system 1 is used, for example, by a moving body M (person) to recognize its own position in an area including a building, but is not limited to this. The position detection system 1 can also be used by others to recognize the position of a moving body M (person, pet, robot, vehicle, etc.) carrying or wearing a mobile terminal 2 in an area including a building. For example, the position detection system 1 may be used by a manager of a building or area to grasp the entry and exit of moving bodies M into and out of an area, the number of moving bodies M located at each position within the area, etc. In such a case, the information output unit 5 may be provided in a smartphone, tablet terminal, computer terminal, etc. used by another person (manager) instead of the mobile terminal 2 carried or worn by the moving body M. Furthermore, the information output unit 5 is configured to output a layout map ML showing the layout of the area as information relating to the area including the position of the mobile terminal 2, but is not limited to this. The information output unit 5 may output text information such as "XX floor, in △△ area" as information relating to the area including the position of the mobile terminal 2. Furthermore, for example, if there is a store in the area, the information output unit 5 may output information relating to the store located near the position of the mobile terminal 2 as information relating to the area including the position of the mobile terminal 2. In the above embodiment, the components of the system main body 3 may be distributed across a plurality of computers that are located at a plurality of locations and capable of communicating with each other. In addition, the configurations described in the above embodiments can be selected or changed as appropriate without departing from the spirit of the present invention. [Explanation of symbols]

[0044] 1 Position Detection System 2. Mobile terminals 3 System unit 4 Speakers 4A 1st speaker 4B 2nd Speaker 4C 3rd Speaker 4D 4th speaker 5 Information output section 11 Passage Room 12A, 12B 13A, 13B entrance / exit 15 Ceiling 16A, 16B Slabs 17 Beds 18. Wall 21 Sound acquisition section 22 Magnetic field measurement section 23 Travel amount measuring section 25 Information Transmission Department 26 Information Receiving Section 31 Storage section 33 Terminal information acquisition unit 35 Position detection unit 37 Information Transmission Department 41 Signal output section 42 Amplifier A, A1, A2 Areas C, C0 cell H Height M Mobile object MG magnetic field map ML Layout Map X Range

Claims

1. A position detection system for detecting a position of a moving object in an area including a building, comprising: a speaker provided in an area set in a region including the building; A storage unit in which a magnetic field map indicating a distribution of a magnetic field in the area in which the speaker is provided is stored; a terminal information acquisition unit that acquires information transmitted from a mobile terminal carried or attached to the mobile object; a position detection unit that detects a position of the moving object in the area, The speaker includes: Emitting a sound based on an acoustic signal including identification information assigned to the speaker; The terminal information acquisition unit identification-related information related to the identification information included in the sound based on the acoustic signal emitted from the speaker in the mobile terminal; magnetic field information relating to a magnetic field measured by the mobile terminal; Movement amount information indicating the movement amount of the mobile terminal is obtainable; The position detection unit setting a position of the speaker that emitted the sound including the identification information, which is acquired by the mobile terminal, as an initial position based on the identification-related information; Obtaining the magnetic field map of the area in which the speaker is provided from the storage unit; Detecting a position of the mobile terminal in the area based on the magnetic field information, the movement amount information indicating the movement amount of the mobile terminal from the initial position, and a distribution of the magnetic field in the magnetic field map. A position detection system comprising:

2. A plurality of the speakers are provided at an entrance to the area at intervals in a direction of entering and exiting the area, The position detection unit A moving direction of the mobile terminal relative to the area is specified based on an acquisition order of the identification information included in the sounds emitted from the plurality of speakers. The location detection system of claim 1 .

3. A position detection method for detecting a position of a moving object in an area including a building by using a speaker provided in an area set in the area including the building and a magnetic field map showing a distribution of a magnetic field in the area, comprising: When a sound based on an acoustic signal including identification information assigned to the speaker is received from the speaker by a mobile terminal carried or attached to the mobile body, identification-related information related to the identification information included in the sound is obtained from the mobile terminal; setting a position of the speaker that emitted a sound including the identification information acquired by the mobile terminal as an initial position based on the received identification-related information; obtaining the magnetic field map of the area in which the loudspeaker is located; acquiring, from the mobile terminal, magnetic field information relating to a magnetic field measured by the mobile terminal and movement amount information indicating a movement amount of the mobile terminal from the initial position; and detecting a position of the mobile terminal in the area based on the magnetic field information, the movement amount information, and a distribution of the magnetic field in the magnetic field map. Location detection methods.

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