Indoor positioning system, indoor positioning method, and indoor positioning program

Abstract

To enable highly accurate determination of location information of people indoors using a simple device even in commercial facilities, high-rise buildings, and other indoor locations where satellite signal reception sensitivity is poor. [Solution] The system comprises a plurality of first devices 1 that are installed indoors and whose indoor positions are identified, and a second device 2 that is carried by a person indoors.The system also comprises a distance calculation means that calculates the distance between each of the plurality of first devices 1 and the second device 2 based on the time of transmission and reception of information or signals in both directions between each of the plurality of first devices 1 and the second device 2, and a location identification means that identifies the location of the second device 2 based on the distance between each of the first devices 1 and the second device 2 calculated by the distance calculation means and the location information of each of the first devices 1.

Description

[Technical Field]

[0001] The present invention relates to an indoor positioning system and an indoor positioning method capable of identifying the current location of a person indoors in a facility such as a commercial facility or a high-rise building in real time. [Background technology]

[0002] Indoors in commercial facilities, high-rise buildings, and other facilities, it is difficult to directly receive satellite signals transmitted from artificial satellites, making it difficult to measure position using Global Navigation Satellite Systems (GNSS), including GPS. This makes it difficult to implement security measures and emergency responses while knowing the location information of people indoors. Therefore, conventional indoor surveillance systems generally rely on CCTV cameras, security guard patrols, and entrance / exit management. Furthermore, emergency responses are handled by security guards through guidance and announcements.

[0003] If accurate location information of people indoors could be obtained, security measures and emergency responses could be implemented based on that location information. Therefore, in order to identify the location of people indoors without using satellite signals, a position measurement system has been proposed that provides highly accurate indoor position measurement by including multiple transmitting devices that are placed in predetermined indoor locations and that transmit first signals including an identifier corresponding to location information of the predetermined location and a transmission time, and a position measurement device that receives the first signals transmitted from the multiple transmitting devices and measures the location based on the location information corresponding to the identifier included in the received first signal and the transmission time (see Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2022-111563 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the following problems have been pointed out in conventional monitoring systems. First, it is difficult for surveillance cameras to cover all areas, and it is difficult to ensure security in blind spots or areas where no cameras are installed. Patrols and security by security guards were also limited because as the size of the facility increased, more security guards were required and they could not be available 24 hours a day. In terms of entrance and exit management, this meant that it was impossible to know where those who entered the building were, and security and emergency response were inadequate. In addition, CCTV camera surveillance systems may affect the privacy of visitors, so they must be handled with care and separate measures are required. In the event of an emergency, waiting for security guards to give instructions or make announcements would slow down the response and would not respond to each individual. As a result, there was no way to provide appropriate guidance or information to each individual. To improve facility security and to guide evacuation and confirm safety in an emergency, it is necessary to know exactly where visitors are on which floor, and to guide them appropriately in an emergency. To do this, it is required to be able to grasp the positions of all people in the building in 3D.

[0006] Furthermore, Patent Document 1 makes it possible to determine the position of a person indoors without using satellite signals. However, although time synchronization is achieved in advance between multiple transmitting devices, time synchronization is not achieved between the transmitting device and the object in which the position calculation unit is installed. As a result, the difference between the time the signal is transmitted from the transmitting device and the time the signal is received by the object varies depending on the object, and there is no guarantee that the position of the object can be calculated accurately. For this reason, it is preferable to synchronize the time between the transmitting device and the object, but adding a separate device for this purpose would make the object more complex and larger.

[0007] The present invention has been made in consideration of the above circumstances, and its main objective is to provide an indoor positioning system and an indoor positioning method that can obtain highly accurate position information of people indoors using simple equipment, even in indoor locations where satellite signal reception sensitivity is poor, such as commercial facilities and high-rise buildings. [Means for solving the problem]

[0008] In order to achieve the above object, the indoor positioning system according to the present invention comprises: An indoor positioning system that identifies a position of a person indoors by using a plurality of first devices that are installed indoors and whose indoor positions are identified, and a second device that is carried by the person indoors, distance calculation means for calculating a distance between each of the plurality of first devices and the second device based on a time of transmission and reception of information or signals in both directions between each of the plurality of first devices and the second device; a position specifying means for specifying a position of the second device based on the distance between each of the first devices and the second device calculated by the distance calculation means and the position information of each of the first devices; It is characterized by having:

[0009] Here, the first device whose indoor position is identified includes not only the case where the indoor position of the first device is identified in advance, but also the case where the indoor position is identified by some means afterwards. Furthermore, the identified position information of the first device may be readably stored in its own storage unit, or may be compiled into a database and stored in another storage device. The indoor location information of the first device is three-dimensional location information, and may be determined using a geocentric Cartesian coordinate system, a geodetic coordinate system, or a coordinate system uniquely set up indoors at the facility. Furthermore, the indoor installation mode of the first device is not particularly limited, and it may be installed on the surface of an indoor pillar, wall, ceiling, etc., or may be embedded in a pillar, wall, ceiling, etc. It may also be fixed to an indoor installation (a structure such as a light or signboard) or a store, etc.

[0010] Having a person indoors carry the second device includes distributing the second device to the person when they enter the building, distributing the second device to the person before they enter the building, and distributing the second device to the person before they enter the building. Alternatively, the second device may be configured as a bracelet, badge, or the like, and may be carried not only on the person's body but also in a pocket, bag, or other personal item. Furthermore, the second device may be substituted for a smartphone carried by the person indoors by installing the application of this system on the smartphone.

[0011] Here, it is desirable to intentionally vary the height position at which the first device is attached, and by managing the height position of the first device, it becomes possible to more accurately identify the three-dimensional position information of the second device.

[0012] Therefore, the distance calculation means calculates the distance between each of the multiple first devices and the second device carried by the person, and the position identification means can identify the position of the second device, i.e., the position of the person indoors, based on the distance between each of the multiple first devices and the second device and the position information of the first device.

[0013] Here, the distance calculation means is The difference between the time on the clock of the first device when the information or signal is transmitted from the first device and the time on the clock of the second device when the information or signal transmitted from the first device is received by the second device; The difference between the time on the clock of the second device when the information or signal is transmitted from the second device and the time on the clock of the first device when the information or signal transmitted from the second device is received by the first device. The propagation time of information or signals between the first device and the second device may be calculated based on the above, and the distance between the first device and the second device may be calculated based on this propagation time. In this way, by calculating the distance between the first device and the second device based on the transmission and reception times of information or signals in each direction between the first device and the second device, it is possible to accurately calculate the propagation time of information or signals between the first device and the second device even if time synchronization is not achieved between the first device and the second device.

[0014] The following system can be constructed by utilizing the indoor positions of people obtained by the above system. That is, a facility information database is provided that stores facility information including an indoor floor map, a destination setting means for setting an indoor destination (emergency stairs, evacuation exit, etc.) by referring to a facility information database, with the location of the second device identified by the location identifying means as a starting point; a route determination means for determining a route from the starting point to the destination set by the destination setting means by referring to the facility information database; a route guidance means for providing guidance via the second device on the route to the destination determined by the route determination means; A system may be constructed that further comprises:

[0015] By using such a system, each person carrying the second device is guided via the second device along the route from their current location to the destination set by the destination setting means, so that in an emergency, each person indoors can be individually guided along the appropriate route from their current location.

[0016] a behavior determination means for determining suspicious behavior of a person carrying the second device based on the location information of the second device identified by the location identification means; an area determination means for determining whether or not a person carrying the second device has entered a prohibited area based on the location information of the second device identified by the location identification means; an alarm issuing means for transmitting an alarm and providing location information of a person carrying the second device when the behavior determining means determines that the person carrying the second device is making suspicious movements or when the area determining means determines that the person carrying the second device has entered a prohibited area; A system may be constructed that further comprises:

[0017] By using such a system, the location of the second device can be identified in real time using the location identification means, so if a person carrying the second device behaves suspiciously, such as not moving for a long period of time or frequently passing in front of a prohibited area, or if the person enters a prohibited area, an alarm will be sent and the location information of the person in question will be provided. [Effects of the Invention]

[0018] As described above, the indoor positioning system, indoor positioning method, and indoor position-side program of the present invention calculate the distance between each of the multiple first devices and the second device based on the time of transmission and reception of information or signals in both directions between each of the multiple first devices and the second device, and the position of a person indoors carrying a second device is identified from this calculated distance between each of the multiple first devices and the second device and the position information of the first device.Therefore, it is possible to obtain highly accurate position information of people indoors using a simple device even in indoor locations where satellite signal reception sensitivity is poor, such as commercial facilities and high-rise buildings. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a diagram showing an example of installation of a first device and a second device of an indoor positioning system according to the present invention. [Figure 2] 1 is a diagram illustrating an example of the configuration of an indoor positioning system according to the present invention. [Figure 3] FIG. 2 is a block diagram showing an example of the configuration of a first device. [Figure 4] FIG. 2 is a block diagram showing an example of the configuration of a second device. [Figure 5] FIG. 2 is a block diagram showing the configuration of a server device. [Figure 6] 10 is a flowchart showing a distance calculation process. [Figure 7] 10 is a flowchart showing a position identification process. [Figure 8] (a) is a diagram showing an example of a display in which the positions of people are superimposed on an illustration of a facility in which all floors of a building are projected from the side, and (b) is a diagram showing an example of a display in which the positions of people are superimposed on a floor plan of a specified floor. [Figure 9] 1 is a flowchart illustrating an example of an emergency response process using the indoor positioning system according to the present invention. [Figure 10] 10 is a flowchart showing an example of a monitoring process using the indoor positioning system according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0020] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

[0021] In FIG. 1 and FIG. 2, the indoor positioning system S includes: The system comprises a first device 1 installed at intervals indoors in a facility such as a commercial facility or a high-rise building, a second device 2 carried by a person indoors (such as a person temporarily entering the facility or a person working indoors in the facility), and a server device 3. The first device 1 is installed at any suitable installation location (such as a wall, a pillar, or the side of an escalator) that is high enough to transmit and receive radio waves indoors, or on an indoor installation (such as a light, an ornamental object or exhibit, or a dedicated installation pole). This first device 1 may be fixed to the surface of the installation location or installation object by appropriate means such as a screw, adhesive, or bracket, or may be attached by being embedded in the installation location or installation object. Each first device 1 has its own three-dimensional position information measured and identified. The three-dimensional position information of the first device 1 may be specified in advance and stored readably inside the first device, or may be specified by some means after the system is started. Also, the three-dimensional position information of the first device 1 may be compiled into a database and stored in a memory unit (storage unit 33 described later) of the server device 3. Here, the three-dimensional position information may be expressed, for example, by latitude, longitude, and ellipsoid height in the WGS84 coordinate system, or by a unique three-dimensional coordinate system set for each indoor area.

[0022] The first device 1 and the second device 2 can be directly connected for communication. The first device 1 can also be connected to a server device 3 via a communication network 4, and the second device 2 can also be connected to the server device 3 via the communication network 4.

[0023] Each of the first device 1 and second device 2 has a built-in clock, and these built-in clocks can be synchronized to a reference time using the method described below.By synchronizing these clocks, it is possible to obtain accurate location information for multiple second devices at the same time.

[0024] Furthermore, the first device 1 can function as the first device 1 with respect to multiple second devices 2, and when multiple second devices 2 exist, each of these multiple second devices 2 can function as the first device with respect to multiple other second devices. In other words, if the exact position of a second device can be identified, the distance between that second device and the other second devices can be calculated and used to identify the positions of the other second devices. In this embodiment, a case will be described in which only the first device is used to identify the location of the second device.

[0025] (Regarding the first device) 3, the first device 1 includes a control unit 11, an RF chip 12, and an oscillator 13, all of which are connected via a bus. The first device 1 also includes a RAM 14 and a storage unit 15, all of which are connected to the control unit 11 via a bus.

[0026] The control unit 11 is composed of a CPU and a ROM, and executes a program stored in the ROM to control the first device 1. The RF chip 12 is equipped with at least a clock 16, but may also be equipped with a phase detector. The RF chip 12 also has a function for processing the transmission and reception of wireless signals, and data received by the RF chip 12 is subjected to arithmetic processing by the control unit 11. The RAM 14 is a work area for the control unit 11, and the storage unit 15 is a memory area for saving programs, data, etc.

[0027] Oscillator 13 oscillates at a predetermined frequency and outputs a signal that provides operational timing for each component of the device. Oscillator 13 can be a crystal oscillator or an atomic oscillator. Clock 16 uses the output signal from oscillator 13 as a source of oscillation to clock and output the time. The time clocked by clock 16 is controlled by control unit 11 to be transmitted to second device 2 via RF chip 12. If a phase detector is further provided, it detects the phase of the carrier wave constituting the information received from second device 2 and also detects the phase of the signal transmitted by oscillator 13 of first device 1.

[0028] RF chip 12 is capable of transmitting and receiving data to and from other computer devices. Data received by this RF chip 12 is stored in RAM 14 or storage unit 15 and is subjected to arithmetic processing by control unit 11. When three-dimensional position information of first device 1 is received via RF chip 12, it is also stored in RAM 14 or storage unit 15 and is controlled by control unit 11 to be transmitted to second device 2 via RF chip 12.

[0029] In the indoor positioning system S, the installation location of the first device 1 is not particularly limited, but since it is used to identify the current location of people inside commercial facilities or high-rise buildings, it is preferable to install it in the above-mentioned location that is visible to as many people as possible, and the installation location can be selected appropriately depending on the infrastructure situation inside the commercial facility or building that uses the indoor positioning system S.

[0030] The first device 1 needs to have its three-dimensional position information identified, but if only planar position information is available, it is a good idea to prepare three-dimensional position information that also includes information on the height at which the first device 1 is installed.

[0031] In order to obtain three-dimensional position information of people in a building, the first devices 1 do not need to be installed on the same plane, and it is preferable that adjacent first devices 1 are installed at different heights. For example, even when the first devices 1 are attached to walls indoors, it is preferable to vary the installation height of the first devices 1 for each wall, manage the installation height of the first devices 1 for each floor, and use this as position information (three-dimensional position information) of the installation location of the first devices 1.

[0032] Furthermore, it is desirable that the first device 1 be installed comprehensively within the building, and in order to cover the entire area within the building, it is advisable to appropriately place the first device 1 in an area where GPS radio waves can be easily received.

[0033] In addition, the location information of the installation location of the first device 1 may be associated with identification information that can identify the first device 1 and stored in its own storage unit 15, or may be stored in the storage unit 33 of the server device 3, or may be made available via the communication network 4 from another management server that manages the location information.

[0034] (Regarding the second device) Next, we will explain the second device 2. This second device 2 is carried by everyone indoors and is configured as an integrated part of an admission pass, bracelet, badge, etc., and may be loaned out, or the application of this system may be installed on a smartphone carried by a person indoors and used as a substitute. The second device 2 may be carried by being attached directly to the person or by being placed in a bag or the like; however, if it is attached to a portable item, the person's location cannot be tracked if the portable item is separated from the person, so it is preferable that it be worn at all times as a bracelet, badge, or the like.

[0035] 4, the second device 2 includes a control unit 21, an RF chip 22, and an oscillator 23, all of which are connected via a bus. The second device 2 also includes a RAM 24 and a storage unit 25, all of which are connected to the control unit 21 via a bus.

[0036] The RF chip 22 includes at least a clock 26 and may optionally include a phase detector.

[0037] The control unit 21 is configured with a CPU and a ROM, and executes programs stored in the storage unit 25 to control the second device 2. The RAM 24 is a work area for the control unit 21, and the storage unit 25 is a memory area for saving programs and data. The control unit 21 performs arithmetic processing based on the programs and data read from the RAM 24 and the storage unit 25, as well as data input from an input unit (not shown).

[0038] The RF chip 22 is capable of transmitting and receiving data to and from other computer devices. Data received by the RF chip 22 is loaded into the RAM 24 and is then subjected to arithmetic processing by the control unit 21.

[0039] Oscillator 23 oscillates at a predetermined frequency and outputs a signal that provides operational timing for each component of the device. Oscillator 23 can be a crystal oscillator or an atomic oscillator. Clock 26 uses the output signal from oscillator 23 as a source of oscillation to clock and output the time. The time clocked by the clock is controlled by control unit 21 to be transmitted to first device 1 via RF chip 22. If a phase detector is provided, it detects the phase of the carrier wave constituting the information received from first device 1 and also detects the phase of the signal oscillated by oscillator 23 of second device 2.

[0040] (About the server) Next, the server device 3 of the present invention will be described. The server device 3 can acquire location information from the second device 2.

[0041] The acquired location information is stored in the server device 3 as location information of the person (second device 2) indoors. The location information of the person (second device 2) is transmitted to the server device 3, for example, from the second device 2 in association with identification information that can identify the second device 2 and the time when the location information was identified. Note that the server device 3 may enable communication between the first device 1 and the second device 2 via smart meters installed in commercial facilities, buildings, etc.

[0042] 5 is a block diagram showing the configuration of a server device 3 according to an embodiment of the present invention. The server device 3 includes at least a control unit 31, a RAM 32, a storage unit 33, and a communication interface 34, all of which are connected via an internal bus. The server device 3 also includes a database 35 for storing information received from the first device 1 and the second device 2. The location information of the first device 1 may also be compiled into a database and stored in the database 35.

[0043] The control unit 31 is composed of a CPU, a ROM, etc., and executes programs stored in the storage unit 33 to control the server device 3. The control unit 31 also has an internal timer that measures time. The RAM 32 is the work area of ​​the control unit 31. The storage unit 33 is a memory area for saving programs and data. The control unit 31 reads out the programs and data from the storage unit 33 or the RAM 32, and executes various controls in this control unit according to the programs based on information received from the first device 1 or the second device 2, etc.

[0044] (Distance calculation process) Next, a process for calculating the distance between first device 1 and second device 2 using the above configuration will be described.

[0045] This distance calculation process is a process of calculating the distance between each first device 1 and the second device 2 based on the propagation time Tp of the information or signal between each first device 1 and the second device 2 when the first device 1 and the second device 2 are within a distance range in which they can send and receive information or signals to each other.

[0046] The distance calculation process is executed at predetermined time intervals (for example, every minute) or whenever a predetermined condition is met, and involves steps S1 to S16 as shown in Fig. 6. For convenience, the case where the distance between one first device 1 and one second device 2 is calculated will be described here.

[0047] First, information or a signal is transmitted from the first device 1 to the second device 2 (step S1). The information or signal transmitted from the first device 1 to the second device 2 is not particularly limited.

[0048] The first device 1 clocks the time (T11) when the information or signal is transmitted in step S1 (step S2), and stores this clocked time in the memory or storage unit 15 in the control unit 11 (step S3).

[0049] Thereafter, in response to this, second device 2 receives the information or signal from first device 1 (step S4). Second device 2 clocks the time (T21) at which the information or signal was received in step S4 (step S5). Then, the clocked time (including the measured phase if the phase is measured) is stored in memory or storage unit 25 within control unit 21 (step S6).

[0050] Next, second device 2 transmits information or a signal to first device 1 (step S7). There are no particular limitations on the information or signal transmitted from second device 2 to first device 1. Second device 2 clocks the time (T22) at which the information or signal was transmitted in step S7 (step S8). The clocked time is then stored in memory or storage unit 25 within control unit 21 (step S9).

[0051] First device 1 receives the information or signal transmitted in step S7 (step S10). First device 1 clocks the time (T12) at which the information or signal was received in step S10 (step S11). Then, the clocked time (including the measured phase if the phase is measured) is stored in memory or storage unit 15 within control unit 11 (step S12).

[0052] Thereafter, the first device 1 transmits the information stored in step S3 about the time (T11) when the signal was transmitted in step S1 and the information stored in step S12 about the time (T12) when the signal was received in step S10 to the second device 2 via the RF chip 12 of the first device 1 (step S13). At this time, the location information of the first device 1 is also transmitted to the second device 2.

[0053] Then, the second device 2 receives information regarding the time (T11) when the first device 1 transmitted the information or signal in step S1, and information regarding the time (T12) when the first device received the information or signal in step S10 (step S14).

[0054] Next, the second device 2 calculates the distance between the first device 1 and the second device 2 (step S15). This distance calculation is performed as follows.

[0055] After transmitting information regarding the clock time (T11) of the first device to the second device 2 via radio waves, the difference between this and the clock time (T21) of the second device 2 when this information is received by the second device 2 is recorded on the second device side as ΔTa. That is, if the clock time of the first device when the information or signal is transmitted from the first device 1 to the second device 2 is defined as T11, and the clock time of the second device when the information or signal transmitted from the first device 1 is received and clocked by the second device 2 is defined as T21, and the difference between these is defined as ΔTa, then this ΔTa (the difference in transmission and reception times when the information or signal is transmitted from the first device 1 to the second device 2) is the difference between the clock times of the first device 1 and the second device 2 (time difference: T20-T10) plus the propagation time (propagation delay) Tp, and so the relationship shown in Equation 1 is obtained. This time difference (T20-T10) will be zero if the clocks of the first device 1 and the second device 2 are synchronized, but here we assume that a time difference (T20-T10) exists (they are not synchronized). [Formula 1] ΔTa=T21-T11=(T20-T10)+Tp

[0056] In order to find this propagation time Tp, the second device 2 also sends information about the time on its clock (T22) to the first device 1, and the difference between this and the time on the clock of the first device 1 (T12) when it is received by the first device 1 is recorded as ΔTb on the first device side. That is, if the time on the clock of the second device when information or a signal is transmitted from the second device 2 to the first device 1 is defined as T22, and the time on the clock of the first device 1 when the information or signal transmitted from the second device 2 is received and clocked by the first device 1 is defined as T12, and the difference between these is defined as ΔTb, then this ΔTb (the difference in transmission and reception times when information or a signal is transmitted from the second device 2 to the first device 1) is the difference between the time on the clock of the first device 1 and the time on the clock of the second device 2 (time difference: T10-T20) plus the propagation time (propagation delay) Tp, and so the relationship shown in Equation 2 is obtained. Here too, the time difference (T10-T20) will be zero if the clocks of the first device 1 and the second device 2 are synchronized, but here we assume that a time difference (T10-T20) exists (they are not synchronized). [Formula 2] ΔTb=T12−T22=(T10−T20)+Tp

[0057] If the time difference between the clocks (T20-T10) and (T10-T20) is added when transmitting from the first device to the second device, then the same amount of time difference will be subtracted when transmitting from the second device to the first device. Therefore, to calculate the propagation time Tp, the terms for the time differences (T20-T10) and (T10-T20) are canceled out by adding together equations 1 and 2, resulting in the relationship given by equation 3. [Formula 3] Tp=(ΔTa+ΔTb) / 2 =((T21-T11)+(T12-T22)) / 2

[0058] Therefore, the propagation time Tp can be calculated based only on the time read by the clock of the first device 1 and the time read by the clock of the second device 2.

[0059] Incidentally, the time difference (T10-T20) between the clock of the first device 1 and the clock of the second device 2 is expressed by the relationship in Equation 4, which is calculated by subtracting Equation 1 from Equation 2. [Formula 4] (T10-T20)=(ΔTa−ΔTb) / 2

[0060] Thereafter, the propagation time calculated by Equation 3 is multiplied by the propagation speed (for example, high speed) of the information or signal to calculate the separation distance between the first device 1 and the second device 2 (step S15).

[0061] Then, the distance between first device 1 and second device 2 calculated in step S15 is stored in the memory in control unit 21 or storage unit 25 (step S16). By executing step S16, the distance calculation process ends.

[0062] Therefore, since equation (3) for calculating the propagation time Tp does not include a term for the time difference (time difference: T20-T10) between the clock of the first device 1 and the clock of the second device 2, the propagation time for information or signals to propagate between the first device 1 and the second device 2 can be calculated regardless of whether there is a time difference between the clock of the first device 1 and the clock of the second device 2 (independent of the time difference (time difference: T10-T20) between the clock of the first device 1 and the clock of the second device 2).

[0063] [Location identification process] Next, we will explain the process of identifying the position of a person wearing second device 2. This position identification process is a process of identifying the position of second device 2 based on the distances between each of multiple first devices 1 and second device 2 calculated in the distance calculation process. Since second device 2 is carried by a person indoors, it can be said that this is a process of identifying the position of a person indoors.

[0064] This position determination process is preferably performed immediately after the distance calculation process is completed. Furthermore, in order to determine the position of the second device 2, it is assumed that the distance calculation device has calculated the distances between one second device 2 and each of the multiple first devices 1.

[0065] In other words, when obtaining three-dimensional position information of a person inside a building (obtaining x, y, z coordinates), it is possible to determine the position of the second device 2 using a well-known multi-point surveying calculation method based on the distance between one second device 2 and at least four first devices 1 and the position information of each of the four first devices 1 used to calculate this distance. Therefore, this system can identify the three-dimensional position of the second device 2 if it can obtain four or more pieces of distance data between the first device 1 and the second device 2. Therefore, it is advisable to appropriately distribute the first devices 1 so that the second device 2 can send and receive information or signals to at least four first devices 1 even if the second device 2 moves. In particular, in areas where positional accuracy is required, it is necessary to adjust the number and three-dimensional positions of the first devices 1 in advance so that the required accuracy can be obtained.

[0066] 7 shows a flowchart of a location specification process according to an embodiment of the present invention. This location specification process can be executed by any of the first device 1, the second device 2, or the server device 3. When the location specification process is executed by the first device 1 or the server device 3, the distance between each of the multiple first devices 1 and the second device 2 and the location information of the first device 1 can be associated with the identification information of the second device 2 and transmitted to the first device 1 or the server device 3 for use.

[0067] First, in order to perform the position identification process, distance information for at least four different first devices 1 and second devices 2 must be acquired at the same or similar times. Here, "similar times" refers to times when the calculated times of the four distances between the first devices 1 and second devices 2 that identify the position of the second device 2 are within a range that does not cause any problems in tracking the movement of the second device. If the distances are not calculated at the same or similar times (for example, when the times at which the propagation times of information or signals between each of the multiple first devices 1 and the second device 2 are measured are the same or similar times), it will be difficult to accurately identify the location of the second device 2 (a person indoors) assuming that the second device 2 is moving.

[0068] First, it is determined whether or not four or more pieces of data on the distance between the first device 1 and the second device 2 have been acquired within a predetermined time range (step S21).

[0069] If four or more pieces of distance data between the first device 1 and the second device 2 are not obtained within a specified time range, accurate three-dimensional position information cannot be obtained even using this position identification method, so the system waits until four or more pieces of distance data are obtained within the specified time range. On the other hand, if four or more pieces of data on the distance between the first device 1 and the second device 2 are acquired within a predetermined time range, three-dimensional position information can be obtained with high accuracy using this position identification method that utilizes wireless two-way time transfer, so the current position of the second device 2 is identified using the above-mentioned multipoint surveying calculation method (step S22), and a display process is performed (step S23), such as displaying the current position of a person (second device 2) indoors on a display screen (not shown) of the server device 3. At the same time, the position information of the second device 2 is preferably stored in the storage unit 33 of the server device 3 together with the calculated time for later use in processing.

[0070] Therefore, if there are four or more first devices 1 that can send and receive signals to a second device 2 carried by a person indoors within a specified time range, the three-dimensional position of the second device 2 is identified by a position identification process based on the distance between each first device 1 and second device 2 calculated by the distance calculation process and the position information of each first device 1 used in this distance calculation.As the person carrying the second device 2 moves, the four first devices 1 that can calculate the distance are switched in sequence, making it possible to continuously capture the position of the second device 2. In this way, if there are four or more first devices 1 capable of calculating distance, it becomes possible to identify the three-dimensional position of the second device 2, and by adjusting the installation locations and installation heights of the first devices and scattering them appropriately, it becomes possible to capture the position of the displacing second device in real time.

[0071] By performing the above processing on all people (people carrying the second device) inside the facility, accurate three-dimensional position information of all people inside can be obtained.For example, as shown in Figure 8, it is possible to switch between display (a) in which the positions of people (positions of the second device 2) are superimposed on an illustration of the facility with all floors projected from the side, and display (b) in which the positions of people are superimposed on a floor plan of a specified floor (1st floor in this example), thereby making it possible to grasp the locations of people in three dimensions.

[0072] In a conventional method of calculating propagation time based on the difference between the transmission time of a transmitting device (corresponding to the first device) and the reception time of a receiving device (corresponding to the second device), even if multiple transmitting devices are time-synchronized, the time between the transmitting device and the receiving device is not synchronized, so if there is a time difference between the two devices, the calculated propagation time will differ from the actual propagation time. In other words, if the receiving device is different, the calculated propagation time may differ. In contrast, according to the present system, the propagation time is calculated based on the transmission and reception times in each direction between the first device 1 and the second device 2, and the distance between the first device 1 and the second device 2 is calculated, so there is no inconvenience of the calculated propagation times being different even if there is a time difference between the first device 1 and the second device 2.

[0073] Furthermore, if the second device 2 carried by each person is not time-synchronized, the location information of everyone in the building at a certain time recorded on the server side will not be accurate (there will be a discrepancy between the location known on the server side at a certain time and the actual location at that time), which could result in incorrect guidance or information being sent in an emergency such as a fire. In an emergency, a one-second delay in response can significantly affect the risk of damage, so all devices (first device 1, second device 2) must be time-synchronized in order for the server side to issue appropriate response instructions at the appropriate time. Therefore, by synchronizing the time of the second device 2 with the time of the first device based on the time difference in equation (4), it becomes possible to synchronize the time of all first devices and second devices by synchronizing the time of multiple first devices at a predetermined timing. This makes it possible to collect accurate location information of all people indoors at the same time, allowing for more accurate response in emergencies.

[0074] Therefore, by using the above indoor positioning system, This technology makes it possible to monitor the movements of people indoors even in blind spots or places where cameras are not installed, which was difficult with conventional surveillance cameras, thereby ensuring security. By using this system, it is possible to minimize the need for security guards to patrol and guard the facility, and also to establish a 24-hour monitoring system. Since it is possible to grasp people's movements indoors in real time, which cannot be covered by entrance and exit management, it becomes possible to adequately respond to security and emergencies. In addition, since camera surveillance is no longer necessary, the privacy of people inside the building is not affected and there is no need to take privacy measures. Even in an emergency, the exact location of people indoors can be determined, making it possible to quickly provide appropriate guidance and information to each person individually via the second device.

[0075] (Example of use of this system) The following systems can be constructed using the indoor positioning system described above. First, we will explain a system that uses this system to propose the optimal route to an indoor destination. This system further includes a facility information database 40 (shown by the dashed line in FIG. 5) in addition to the configuration shown in FIG. The facility information database 40 stores layout information for each floor, such as the indoor floor plan, the location of elevators and stairs, the width and length of each passage, and passable and non-passable areas.

[0076] Using this facility information database 40, in emergencies that require a rapid response, such as fires and earthquakes, it is also possible to perform the processing shown in Fig. 9. That is, in the case of a fire, the server device 3 determines whether or not an emergency has occurred based on the activation of fire detectors or sprinklers, etc. In the case of an earthquake, it determines whether or not an emergency has occurred based on the magnitude and duration of shaking caused by the earthquake (step S30). If it is determined that the situation is not an emergency, real-time location information obtained from the second device 2 carried by each person is collected together with time information and stored in the database 35 (step S31).

[0077] On the other hand, if it is determined that an emergency has occurred, the location information of all people in the building (location information of the second device 2) is collected in real time using the second device 2 carried by each person (step S32), and an evacuation point (evacuation exit) is set as the destination based on each person's current location (step S33), and the facility information stored in the facility information database 40 is referenced to calculate the shortest and most optimal evacuation route from the current location to the destination. At this time, the shortest and safest route is calculated from the facility information, taking into consideration conditions such as the width of the aisles, the layout of the equipment, and the number of people on the same floor (step S34). Then, information about the calculated route is transmitted to the second device 2, and based on that, the route is displayed in a visible manner on the display unit of the second device 2 (for example, see the dashed line in Figure 8(b)), and the direction in which to move from the current position is announced by voice, thereby providing guidance along the calculated route (step S35). When setting the destination and calculating the route, the nearest emergency exit from each person's current location may be selected, or the optimal route may be calculated taking into account overcrowding and impassable areas.

[0078] Therefore, with the above system, even in an emergency, accurate location information of people inside commercial facilities or high-rise buildings can be collected in real time, making it possible to accurately grasp the locations and movements of people inside, and also to provide appropriate guidance and information individually according to each person's location.

[0079] This system is also effective for enhancing security in commercial facilities and buildings. Since the server device 3 can grasp the exact location of people inside the building in real time, as shown in Fig. 10, by monitoring the location of the second device 2 carried by each person (step S40), it is possible to determine whether anyone is behaving suspiciously (step S41) and whether anyone is entering a prohibited area (step S42).

[0080] Here, suspicious behavior includes staying in the same place for a long period of time, or frequently passing near places where confidential information is stored or where cash is kept. In addition, entering a non-permitted area refers to entering an area that requires prior permission without obtaining permission, and may include deviating from permitted areas or routes. If the server device 3 determines that there is suspicious activity or that there has been an intrusion into a prohibited area, it sends a warning to the security guard (step S43) and also provides the security guard with location information of the suspicious person (step S44).

[0081] Therefore, the above system makes it possible to collect accurate location information of people inside commercial facilities and high-rise buildings in real time, making it possible to grasp suspicious movements and intrusions into unauthorized areas without having to deploy security guards. Security guards tend to be limited in scope, but if this system is used instead, it will be possible to provide 24-hour security throughout the entire building. [Explanation of symbols]

[0082] 1 1st device 2 Second device 3. Server equipment S Indoor Positioning System

Claims

1. An indoor positioning system that identifies a position of a person indoors by using a plurality of first devices that are installed indoors and whose positions within the indoors are identified, and a second device that is carried by the person indoors, distance calculation means for calculating a distance between each of the plurality of first devices and the second device based on a time of transmission and reception of information or signals in both directions between each of the plurality of first devices and the second device; a position specifying means for specifying a position of the second device based on the distance between each of the first devices and the second device calculated by the distance calculation means and the position information of each of the first devices; An indoor positioning system comprising:

2. a facility information database for storing facility information including the indoor floor map; a destination setting means for setting a destination within the indoor area by referring to the facility information database, with the location of the second device identified by the location identifying means as a starting point; a route determination means for determining a route from the starting point to the destination set by the destination setting means by referring to the facility information database; a route guidance means for providing guidance via the second device on the route to the destination determined by the route determination means; 2. The indoor positioning system according to claim 1, further comprising:

3. a behavior determination means for determining suspicious behavior of a person carrying the second device based on the location information of the second device identified by the location identification means; an area determination means for determining whether or not a person carrying the second device has entered a prohibited area based on the location information of the second device identified by the location identification means; an alarm issuing means for transmitting an alarm and providing location information of a person carrying the second device when the behavior determining means determines that the person carrying the second device is making a suspicious movement or when the area determining means determines that the person carrying the second device has entered a prohibited area; and 2. The indoor positioning system according to claim 1, further comprising:

4. The distance calculation means The difference between the time on the clock of the first device when the first device transmits information or a signal and the time on the clock of the second device when the second device receives the information or signal transmitted from the first device; The difference between the time on the clock of the second device when the second device transmits information or a signal and the time on the clock of the first device when the first device receives the information or signal transmitted from the second device.

2. The indoor positioning system according to claim 1, further comprising: a signal processing unit for processing the information or signal between the first device and the second device; a signal processing unit for processing the information or signal between the first device and the second device; and a signal processing unit for processing the information or signal between the first device and the second device based on the signal processing unit;

5. 1. An indoor positioning method for identifying a position of a person indoors by using a plurality of first devices installed indoors and whose indoor positions are identified, and a second device carried by the person indoors, a distance calculation step of calculating a distance between each of the plurality of first devices and the second device based on a time of transmission and reception of information or signals in both directions between each of the plurality of first devices and the second device; a position specifying step of specifying a position of the second device based on the distances between the first device and the second device calculated in the distance calculation step and position information of the first device; An indoor positioning method comprising:

6. a facility information database for storing facility information including the indoor floor map; a destination setting step of setting the indoor destination by referring to the facility information database, with the location of the second device identified by the location identifying step as a starting point; a route determination step of determining a route from the starting point to the destination set in the destination setting step by referring to the facility information database; a route guidance step of guiding, via the second device, the route to the destination determined in the route determination step; 6. The indoor positioning method according to claim 5, further comprising:

7. a behavior determination step of determining suspicious behavior of a person carrying the second device based on the location information of the second device identified by the location identification step; an area determination step of determining whether or not a person carrying the second device has entered a unauthorized area based on the location information of the second device identified by the location identification step; an alarm issuing step of transmitting an alarm and providing location information of the person in question when the behavior determining step determines that the person carrying the second device is making a suspicious movement or when the area determining step determines that the person carrying the second device has entered a unauthorized area; 6. The indoor positioning method according to claim 5, further comprising:

8. An indoor positioning program used in an indoor positioning system that identifies a position of a person indoors by using a plurality of first devices that are installed indoors and whose indoor positions are identified, and a second device that is carried by the person indoors, On the computer, distance calculation means for calculating a distance between each of the plurality of first devices and the second device based on a time of transmission and reception of information or signals in both directions between each of the plurality of first devices and the second device; a position specifying means for specifying a position of the second device based on the distance between each of the first devices and the second device calculated by the distance calculation means and the position information of each of the first devices; Indoor positioning program for executing the above.

9. The indoor positioning system includes a facility information database that stores facility information including the indoor floor map; The computer, a destination setting means for setting a destination within the indoor area by referring to the facility information database, with the location of the second device identified by the location identifying means as a starting point; a route determination means for determining a route from the starting point to the destination set by the destination setting means by referring to the facility information database; a route guidance means for providing guidance via the second device on the route to the destination determined by the route determination means; 9. The indoor positioning program according to claim 8, further comprising:

10. The computer, a behavior determination means for determining suspicious behavior of a person carrying the second device based on the location information of the second device identified by the location identification means; an area determination means for determining whether or not a person carrying the second device has entered a prohibited area based on the location information of the second device identified by the location identification means; an alarm issuing means for transmitting an alarm and providing location information of a person carrying the second device when the behavior determining means determines that the person carrying the second device is making a suspicious movement or when the area determining means determines that the person carrying the second device has entered a prohibited area; and 9. The indoor positioning program according to claim 8, further comprising:

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