JP6324430B2 - Positioning system - Google Patents

Description

  The present invention relates to a positioning system that transmits acoustic signals from a plurality of transmitters and measures the position of the receiver based on the acoustic signals received by the receiver.

  Conventionally, various techniques have been proposed for measuring the position of a moving object existing in a monitoring space. As one of them, an acoustic signal such as an ultrasonic wave is transmitted from a plurality of transmitters installed in a monitoring space, and based on the acoustic signal received by the receiver carried on the moving object and the arrangement of the transmitter, Some measure the position, that is, the position of the moving object.

  For example, Patent Document 1 discloses a system that transmits ultrasonic signals from a plurality of relay stations and measures the position of the mobile terminal in the monitoring space based on the phase difference from the starting point of the ultrasonic signal received by the mobile terminal. Is disclosed. In the system described in Patent Document 1, a plurality of relay stations are arranged discretely or meshed at intervals in the vertical and horizontal directions, and each relay station is assigned by a time slot assigned in time division. Transmit ultrasonic signals in order.

JP 2011-117880 A

  When the position of a moving object existing in a monitoring space is measured using a plurality of transmitters, the number of transmitters necessary to cover the space increases as the monitoring space becomes wider. For this reason, when each transmitter transmits ultrasonic signals in order as in the system described in Patent Document 1, as the monitoring space becomes wider, until all transmitters finish transmitting ultrasonic signals. It takes a long time. That is, there is a high possibility that the position of the moving object will change greatly by the time all the transmitters have finished transmitting the ultrasonic signal. Therefore, based on the ultrasonic signal received by the receiver carried by the moving object. As a result, it is difficult to accurately measure the position of the moving object.

  Therefore, the present invention has been made in view of the above problems, and provides a positioning system capable of accurately measuring the position of a moving object carrying a receiver even when the monitoring space is wide. For the purpose.

  In order to achieve such an object, the present invention is a positioning system for measuring the position of a receiver in a monitoring space, each of which is arranged at a predetermined installation position in the monitoring space, and in a group to which the own device belongs. A plurality of first acoustic signals that are transmitted in a transmission order that is unique and overlapped between groups, and that transmit a second acoustic signal with a group time difference unique to the group to which the own device belongs from the transmission of the first acoustic signal A transmitter that receives the first acoustic signal and the second acoustic signal, a storage unit that stores the installation position, the transmission order, and the group time difference of each of the plurality of transmitters, Detecting the first acoustic signal and the second acoustic signal having a predetermined intensity or more received by the receiver as a first reception signal and a second reception signal, respectively, The transmission unit of the first reception signal is identified by comparing the time difference between the first reception signal and the second reception signal with the transmission order and the group time difference stored in the storage unit, And a signal analyzer that measures the position of the receiver from the installation position of the transmission source stored in the transmission source, and the plurality of transmitters receive at least the first reception signal from any of the transmission sources. The transmitters having the same transmission order are separated from each other by a distance at which the first reception signal from the transmitter having the same transmission order as the transmission source is not detected at the detected position in the monitoring space. A positioning system characterized by the above is provided.

  In addition, each of the plurality of transmitters preferably transmits the first acoustic signal and the second acoustic signal in mutually different frequency bands.

  ADVANTAGE OF THE INVENTION According to this invention, even if monitoring space is wide area, the position of the receiver which received the said acoustic signal can be correctly measured using the acoustic signal transmitted from the some transmitter.

It is a figure which shows typically the monitoring space in this Embodiment. It is a figure which shows the whole structure of the positioning system in this Embodiment. It is a figure which shows the functional block diagram of the transmitter in this Embodiment. It is a figure which shows typically the transmission timing of the acoustic signal in this Embodiment. It is a figure which shows the functional block diagram of the receiver in this Embodiment. It is a figure which shows typically arrangement | positioning of the transmitter in this Embodiment. It is a figure which shows typically the other example of arrangement | positioning of a transmitter. It is a figure which shows the received waveform of the receiver in this Embodiment. It is a figure which shows the received waveform in the time slot in this Embodiment. It is a flowchart of the synchronous signal transmission process in this Embodiment. It is a flowchart of the acoustic signal transmission process in this Embodiment. It is a flowchart of the positioning process in this Embodiment.

  Embodiments of a positioning system according to the present invention will be described below. FIG. 1 is a diagram schematically showing a monitoring space in the present embodiment. In the present embodiment, an example of a positioning system that measures the position of a person 5 existing in a monitoring space using the indoor area of a wide-area facility as a monitoring space (region 6 indicated by a dotted line) will be described. The positioning system in the present embodiment transmits acoustic signals from a plurality of transmitters 3 installed at a predetermined interval (for example, at an interval of 4 meters) on the ceiling of the facility, and the acoustic signals received by the receiver 4 existing in the facility. Based on the above, the position of the receiver 4 is measured. At this time, in this embodiment, the position of the receiver 4 is measured as the position of the person 5 by carrying or mounting the receiver 4 on the person 5. In the present embodiment, as shown in FIG. 1, a total of 36 transmitters 3 are installed in the monitoring space.

  In addition, although this Embodiment demonstrates the positioning system which measures the position of a person indoors, the positioning system of this invention is not restricted to this embodiment. For example, it may be used for positioning outdoors, or a receiver may be attached to an article such as a cargo instead of a person and used for positioning the article.

<System configuration>
FIG. 2 is a diagram showing an overall configuration of the positioning system 1 in the present embodiment. As shown in FIG. 2, the positioning system 1 includes a management device 2, a plurality of transmitters 3, and a receiver 4 that is carried by a moving object such as a person.

  In the positioning system 1, the management device 2 and the plurality of transmitters 3 are connected by a communication network. The communication network may be realized by wired connection or may be realized by wireless connection. Moreover, you may make it connect the management apparatus 2 and the receiver 4 with a communication network as needed.

  Hereinafter, each configuration of the positioning system 1 will be described in detail with reference to the drawings.

<Management device 2>
As illustrated in FIG. 2, the management device 2 includes a communication unit 21, a storage unit 22, and a synchronization signal transmission unit 23. In the present embodiment, the management device 2 transmits a synchronization signal to the plurality of transmitters 3. Specifically, the synchronization signal transmission unit 23 refers to the positioning cycle stored in the storage unit 22, and transmits all the transmitters 3 constituting the positioning system 1 via the communication unit 21 in the cycle. Send synchronization signals all at once. In the present embodiment, the positioning system 1 measures the position of the receiver 4 once every time the synchronization signal is transmitted from the synchronization signal transmission unit 23 to the plurality of transmitters 3 once. That is, the positioning cycle stored in the storage unit 22 is information corresponding to a cycle in which the positioning system 1 performs positioning. Here, the positioning cycle is set in consideration of “the time from when the synchronization signal is transmitted until all transmitters 3 constituting the positioning system 1 transmit the acoustic signal and the reverberation component attenuates”, Prestored in the storage unit 22.

The storage unit 22 includes a semiconductor device such as a ROM (Read Only Memory) and a RAM (Random Access Memory), and a memory device such as a hard disk. As described above, the storage unit 22 stores the positioning cycle. In addition, the storage unit 22 stores information necessary for each process of the positioning system 1, and transmits the transmitter 3 and the receiver 4 via the communication unit 21. The information may be transmitted / received to / from.

The synchronization signal transmission unit 23 includes at least one processor such as a CPU (Central Processing Unit), a DSP (Digital Signal Processor), an MCU (Micro Control Unit), and its peripheral circuits. As described above, the synchronization signal transmission unit 23 transmits the synchronization signal to all the transmitters 3 constituting the positioning system 1 according to the positioning cycle stored in the storage unit 22. In the present embodiment, the synchronization signal transmission unit 23 is described as one of the configurations of the management device 2, but the positioning system 1 is configured with the synchronization signal transmission unit 23 as a device different from the management device 2. May be. In this case, the synchronization signal transmission unit 23 is connected to the management device 2 and the transmitter 3 through a communication network, refers to the positioning cycle stored in the storage unit 22 of the management device 2, and transmits a synchronization signal to the transmitter 3. Can be sent.

<Transmitter 3>
A plurality of transmitters 3 are installed in the monitoring space, and each transmits an acoustic signal to the monitoring space at a predetermined timing. FIG. 3 is a functional block diagram of the transmitter 3 in the present embodiment. As shown in FIG. 3, the transmitter 3 includes a communication unit 31, a storage unit 32, a transmission control unit 33, and an acoustic signal transmission unit 34.

  The communication unit 31 transmits and receives various types of information to and from the management device 2. In the present embodiment, the communication unit 31 receives the synchronization signal transmitted from the synchronization signal transmission unit 23 of the management device 2.

  The storage unit 32 includes a semiconductor memory such as a ROM and a RAM, and a memory device such as a hard disk. The storage unit 32 stores various information such as a program for executing each process in the transmitter 3, setting data, and generated data. For example, the storage unit 32 stores two types of IDs (group ID and transmission order ID) related to the transmitter 3 and a signal transmission cycle. Hereinafter, these pieces of information will be described in detail.

  First, the group ID will be described. The plurality of transmitters 3 constituting the positioning system 1 are divided into a predetermined number of groups each including a predetermined number of transmitters 3 in advance. The group ID is an ID for identifying the group to which the transmitter 3 belongs. That is, the same group ID is stored in the storage unit 32 of the transmitter 3 belonging to the same group. In this embodiment, the group ID is a continuous integer of 1 or more. For example, a plurality of transmitters 3 constituting the positioning system 1 are divided into four groups (group 1, group 2, group 3, group 4). In this case, group IDs for identifying each group are “1”, “2”, “3”, and “4”, respectively.

  Next, the transmission order ID will be described. The transmission order ID is an ID for identifying the transmission order of the transmitters 3 in the group to which the transmission order ID belongs. Each transmitter 3 transmits acoustic signals to the monitoring space in the order determined by the transmission order ID. Here, the transmission order IDs are assigned different IDs between transmitters 3 with the same group, but the same IDs are allowed to be assigned between transmitters 3 with different groups. ing. That is, in the positioning system 1, transmitters 3 belonging to different groups are allowed to simultaneously transmit acoustic signals to the monitoring space, and these transmitters 3 are assigned the same transmission order ID. . In this embodiment, the transmission order ID is a continuous integer starting from 1 (the number of transmitters 3 constituting the group is the upper limit). For example, in the present embodiment, all the 36 transmitters 3 installed in the monitoring space are divided into four groups composed of nine transmitters 3. For this reason, the transmission order ID given to the transmitter 3 is an integer from 1 to 9.

  The transmission order ID will be described more specifically. A transmission order ID “1” is assigned to the transmitter 3 having the first transmission order of the acoustic signals in the group 1, and the second transmission order is transmitted in the group 1. The transmission order ID “2” is assigned to the machine 3, and similarly, the transmission order ID “9” is assigned to the transmitter 3 having the last transmission order in the group 1. A transmission order ID “1” is assigned to the transmitter 3 having the first transmission order of the acoustic signals in the group 2, and a transmission order ID “2” is assigned to the transmitter 3 having the second transmission order in the group 2. Similarly, the transmission order ID “9” is assigned to the transmitter 3 having the last transmission order in the group 2. Similarly, transmission order IDs are assigned to the groups 3 and 4 as well. Here, in the present embodiment, the transmitters 3 to which the same transmission order ID is assigned transmit acoustic signals to the monitoring space at the same time. For example, the group 1 to which the transmission order ID “1” is assigned. Transmitter 3, a group 3 transmitter 3 with a transmission order ID “1”, a group 3 transmitter 3 with a transmission order ID “1”, and a transmission order ID “1” The transmitter 3 of group 4 transmits an acoustic signal simultaneously to the monitoring space.

  Next, the signal transmission cycle will be described. The signal transmission cycle is a transmission interval of acoustic signals between the transmitters 3 in which the transmission order is continuous. In the present embodiment, the signal transmission period is information corresponding to a transmission interval of a main band signal (described later) included in the acoustic signal. The signal transmission cycle is set in consideration of the reverberation time of the monitoring space where the positioning system 1 is installed. Specifically, the signal transmission cycle includes a direct wave of the acoustic signal transmitted from the transmitter 3, a reverberation component of the acoustic signal transmitted from the transmitter 3 whose transmission order is one before the transmitter 3, and Is set to a length considering the time until the reverberation component of the acoustic signal transmitted immediately before is sufficiently attenuated. That is, the signal transmission cycle is set to a short time in a monitoring space with a short reverberation time, and is set longer as the reverberation time becomes longer. For example, in this embodiment, the signal transmission cycle is 50 ms.

  The group ID, transmission order ID, and signal transmission cycle described above are stored in advance in the storage unit 32 of each transmitter 3. However, the method by which the transmitter 3 acquires these pieces of information is not particularly limited, and an existing technique may be used. For example, the group ID and the transmission order ID may be stored in the storage unit 32 by reading the state of a dip switch (not shown) provided in each transmitter 3. The storage unit 22 of the management device 2 stores in advance the group IDs and transmission order IDs of all the transmitters 3 constituting the positioning system 1 and the signal transmission period of the positioning system 1. The own group ID, transmission order ID, and signal transmission cycle may be acquired via the communication unit 31 and stored in the storage unit 32.

  The transmission control unit 33 is configured to include at least one processor such as a CPU, DSP, MCU, and its peripheral circuits. The transmission control unit 33 refers to the group ID, the transmission order ID, and the signal transmission cycle stored in the storage unit 32 and controls transmission of the acoustic signal in the transmitter 3. Specifically, the transmission control unit 33 generates digital data of the acoustic signal, and transmits the acoustic signal to the monitoring space at a timing determined by the group ID, the transmission order ID, and the signal transmission cycle. Is output to an acoustic signal transmitter 34 described later. Hereinafter, the acoustic signal transmitted from the transmitter 3 will be described in detail.

  First, the format of the acoustic signal transmitted by the transmitter 3 will be described. In the present embodiment, a baseband TSP (Time Stretched Pulse) frequency-modulated into an ultrasonic band is transmitted as an acoustic signal. Here, it is preferable to select a continuous band including both a band having a high sound pressure in the transmitter 3 and a band having a high sensitivity of the receiver 4 as the band to be frequency-modulated.

  Although details will be described later, the acoustic signal of the present embodiment includes a first signal that is a signal in a first frequency band (hereinafter referred to as a main band) and a second frequency band (hereinafter referred to as a subband). The second signal, which is a signal of Here, the main band and the subband are selected from the above-described preferable frequency bands, respectively. For example, in this embodiment, 24 kHz to 28 kHz is a main band, and 28 kHz to 32 kHz is a subband.

  Note that the format of the acoustic signal transmitted from the transmitter 3 is not limited to that described above. For example, instead of TSP, a signal obtained by frequency-modulating an M sequence may be used as the acoustic signal. Also, an encoded signal or burst pulse signal using BPSK (Binary Phase Shift Keying) or QPSK (Quad Phase Shift Keying) may be used without using a wideband signal such as TSP or M-sequence. In this case, a general ultrasonic transmission element of 25 kHz and 40 kHz may be used in the transmitter 3, and an ultrasonic reception element of the same frequency may be used in the receiver 4, and one of 25 kHz and 40 kHz is a main band, The other band may be a subband. In the present embodiment, an ultrasonic band signal is used as the acoustic signal, but an audible band signal may be used.

  Next, the first signal and the second signal described above will be described in detail. The transmission control unit 33 refers to the group ID stored in the storage unit 32 and controls to transmit an acoustic signal specific to the group ID. Specifically, the transmission control unit 33 generates digital data of the first signal and the second signal in the signal format described above, and these signals are transmitted to the monitoring space at a time interval determined for each group ID. As described above, the digital data of the first signal and the digital data of the second signal are output to the acoustic signal transmission unit 34 at the time interval. In the present embodiment, a signal composed of the first signal and the second signal is referred to as an “acoustic signal”. The time interval may be stored in the storage unit 32 in association with the group ID, or the time interval value may be stored as the group ID value. The time interval associated with the group ID may be 0 or more.

  The time interval between the first signal and the second signal is set to be as short as possible within a range in which the receiver 4 can distinguish different time intervals for each group ID. For example, in this embodiment, when the receiver 4 has a resolution capable of identifying a time difference of 1 ms, if the group ID is “1”, the time interval is “1 ms”, and if the group ID is “2”. The time interval may be “2 ms”, the time interval may be “3 ms” if the group ID is “3”, and the time interval may be “4 ms” if the group ID is “4”. As described above, in the present embodiment, transmission control unit 33 generates the first signal and the second signal in different frequency bands (main band and subband). As a result, the receiver 4 can distinguish the first signal and the second signal without being affected by the reverberation components of each other, so that the time interval between the first signal and the second signal is further shortened. It becomes possible to set to. Note that the first signal and the second signal may be transmitted in the same frequency band.

  Next, the transmission timing of the acoustic signal in the transmitter 3 will be described. The transmitter 3 refers to the transmission order ID and the signal transmission period stored in the storage unit 32, and transmits the acoustic signal in the order determined by the transmission order ID and the period determined by the signal transmission period. Specifically, when the transmission control unit 33 of each transmitter 3 receives the synchronization signal from the management device 2 via the communication unit 31, first, the transmission control unit 33 controls to transmit the SYNC signal to the monitoring space. That is, digital data of the SYNC signal is generated and output to the acoustic signal transmission unit 34 described later. The SYNC signal may be a pulse signal generated in the main band described above. Thereafter, the transmission control unit 33 waits until it reaches its own transmission timing determined by the transmission order ID, and controls to transmit the first signal among the generated acoustic signals to the monitoring space at the transmission timing. After that, when the time interval determined by the group ID has elapsed, control is performed so that the second signal among the generated acoustic signals is transmitted to the monitoring space, and the acoustic signal is transmitted again until the synchronization signal is received from the management device 2. Wait. For example, in the present embodiment, when the transmission order ID is i and the signal transmission cycle is T, the transmission control unit 33 controls the transmission of the SYNC signal, and then waits for i · T and outputs the acoustic signal. Control to send. Thereby, the transmitter 3 of the positioning system 1 can transmit the acoustic signal in the order determined by the transmission order ID and in the period determined by the signal transmission period. Further, every time a synchronization signal is transmitted from the management device 2, all the transmitters 3 constituting the positioning system 1 can transmit the acoustic signal once.

  Here, the transmission timing of the acoustic signal will be described more specifically with reference to FIG. FIG. 4 is a diagram schematically showing the transmission timing of the acoustic signal in the present embodiment. As described above, since the positioning system 1 according to the present embodiment divides all 36 transmitters 3 into four groups each including nine transmitters 3, FIG. For each of the four groups, the transmission timings of the acoustic signals transmitted from the nine transmitters 3 belonging to each group are shown. In FIG. 4, the black arrow represents the transmission time of the first signal, and the white arrow represents the transmission time of the second signal. The numbers surrounded by circles correspond to the transmission order ID of the transmitter 3. Circled 1 indicates an acoustic signal of the transmitter 3 to which transmission order ID = 1 is assigned. Similarly, circled 2, 3 and 9 indicate transmission order ID = 2, 3 respectively. , 9 are acoustic signals of the transmitter 3 assigned. In addition, illustration is abbreviate | omitted about the acoustic signal of the transmitter 3 to which transmission order ID = 4-8 was provided.

  As shown in FIG. 4, first, when the transmitter 3 receives a synchronization signal from the management device 2, it transmits a SYNC signal. The SYNC signal is transmitted from all transmitters 3 at the same time. Thereafter, when the signal transmission cycle T elapses from the transmission time point of the SYNC signal, the transmitters 3 having the transmission order ID “1” of each group simultaneously transmit the first signal. When the time interval Dn (n = 1 to 4) determined by each group ID has elapsed, the second signal is transmitted. Specifically, the transmitter 3 having the transmission order ID “1” in the group 1 transmits the second signal at the time interval D1, and the transmitter 3 having the transmission order ID “1” in the group 2 is the second signal at the time interval D2. The transmitter 3 with the transmission order ID “1” of the group 3 transmits the second signal at the time interval D3, and the transmitter 3 with the transmission order ID “1” of the group 4 is the second at the time interval D4. Send a signal. Thereafter, when 2T elapses from the transmission time point of the SYNC signal, the transmitters 3 having the transmission order ID “2” of each group simultaneously transmit the first signal. Then, similarly to the transmitter 3 of the group 1, the second signal is transmitted when a time interval Dn (n = 1 to 4) determined by each group ID has elapsed. Thereafter, similarly, the transmitters 3 having the transmission order IDs “3” to “9” sequentially transmit the first signal and the second signal. Each transmitter 3 waits for transmission of an acoustic signal from the management device 2 until it receives a synchronization signal again. That is, when the transmitter 3 having the transmission order ID “9” finishes transmitting the acoustic signal, the transmitter 3 of the positioning system 1 waits for the transmission of the acoustic signal until the synchronization signal is transmitted again from the management device 2. .

  Returning to FIG. 3, the acoustic signal transmission unit 34 of the transmitter 3 will be described.

  The acoustic signal transmission unit 34 includes a DA converter, a power amplifier, and a speaker. The acoustic signal transmission unit 34 transmits the acoustic signal to the monitoring space every time digital data of the acoustic signal is output from the transmission control unit 33. Specifically, when digital data of an acoustic signal is input from the transmission control unit 33, the digital data is converted into analog data by a DA converter, the analog data is amplified by a power amplifier, and then from a speaker. Send. That is, in this embodiment, every time digital data of the SYNC signal, the first signal, and the second signal generated by the transmission control unit 33 is input to the acoustic signal transmission unit 34, the digital data is converted into analog data. Convert and send from the speaker. Since the transmission control unit 33 outputs the digital data of each signal to the acoustic signal transmission unit at the transmission timing of each signal described above, the acoustic signal transmission unit 34 transmits each signal to the monitoring space at each transmission timing. It becomes possible to transmit.

  The positioning system 1 of the present invention divides a plurality of transmitters 3 constituting the system into a predetermined number of groups each including a predetermined number of transmitters 3, and the transmitters 3 are transmitted in a transmission order determined within the group. An acoustic signal is transmitted to the monitoring space. At this time, since the transmitters 3 in the same transmission order in each group simultaneously transmit the acoustic signals to the monitoring space, the time required for all the transmitters 3 constituting the positioning system 1 to finish transmitting the acoustic signals is 1 It depends on the number of transmitters 3 constituting one group and the signal transmission cycle. That is, if the number of transmitters 3 is reduced, the time required for all the transmitters 3 to finish transmitting acoustic signals can be shortened. Of course, in the positioning system 1 of the present invention, since the first signal and the second signal are transmitted at a time interval determined for each group ID, the maximum value of the time interval increases as the number of groups increases. However, in the positioning system of the present invention, since the interference can be eliminated by generating the first signal and the second signal in different frequency bands, the time interval between the first signal and the second signal is set to a short time. be able to. That is, according to the positioning system 1 of the present invention, even if the number of groups increases, it is possible to keep the time required for all the transmitters 3 constituting the positioning system 1 to finish transmitting the acoustic signal in a short time. Become. Conventionally, each transmitter that constitutes a system transmits an acoustic signal in order, so that as the number of transmitters necessary to cover the area of the monitoring space increases, all the transmitters 3 become acoustic. It takes a long time to complete the transmission of the signal. That is, conventionally, as the monitoring space becomes wider, there is a problem that the time required for all the transmitters 3 to finish transmitting the acoustic signal becomes longer. However, according to the present invention, as described above, even when the monitoring space becomes a wide area, the time required for all the transmitters 3 constituting the positioning system 1 to finish transmitting the acoustic signal is kept short. Is possible.

  In addition, when the monitoring space becomes wider, in the positioning system 1 of the present invention, it is necessary to set more groups, so the time interval between the first signal and the second signal that increases as the number of groups increases, There is a possibility that the influence on the time required for all the transmitters 3 to finish transmitting the acoustic signal cannot be ignored. However, since the acoustic signal of the present invention is not limited to the one composed of the first signal and the second signal, the acoustic signal transmitted from the transmitter 3 is composed of the first signal, the second signal, and the third signal. Thus, the frequency band of the third signal may be different from the main band and the subband. Then, as the time interval determined according to the group ID, the time interval between the first signal and the second signal and the time interval between the first signal and the third signal may be adopted. Thereby, even if the number of groups is further increased, it is possible to keep the time required for all the transmitters 3 constituting the positioning system 1 to finish transmitting the acoustic signal in a short time.

<Receiver 4>
The receiver 4 is present in the monitoring space and receives the acoustic signal transmitted from the transmitter 3. In the present embodiment, the receiver 4 is carried or worn by a person existing in the monitoring space, and measures its own position in the monitoring space based on the received acoustic signal. Then, the receiver 4 outputs the measured position of itself as the position of the person. FIG. 5 is a functional block diagram of the receiver 4 in the present embodiment. As shown in FIG. 5, the receiver 4 includes an acoustic signal receiving unit 41, a storage unit 42, a signal analysis unit 43, and an output unit 44.

  The acoustic signal receiving unit 41 includes a microphone, a microphone amplifier, and an A / D converter. The acoustic signal receiving unit 41 receives the acoustic signal transmitted from the transmitter 3 as needed. Specifically, the acoustic signal receiving unit 41 collects an acoustic signal transmitted to the monitoring space with a microphone, amplifies analog data of the collected sound with a microphone amplifier, and then uses an A-D converter. Convert to digital data. Then, the acoustic signal receiving unit 41 outputs the converted digital data to the signal analyzing unit 43 described later. Note that digital data may be output to the signal analysis unit 43 via the storage unit 42 described later.

  The storage unit 42 includes a semiconductor memory such as a ROM and a RAM, and a memory device such as a hard disk. The storage unit 42 stores various information such as a program for executing each process in the receiver 4, setting data, and generated data. For example, the storage unit 42 stores height information, a group ID table, a transmission order ID table, and arrangement information of the transmitter 3. Hereinafter, these pieces of information will be described in detail. Note that the storage unit 42 also stores the signal transmission cycle in the same manner as the storage unit 32 of the transmitter 3.

  First, height information will be described. The height information is information indicating the height from the floor surface of the receiver 4 in the monitoring space, and is used when the position of the receiver 4 is measured by the signal analysis unit 43 described later. In the present embodiment, since the receiver 4 is carried or worn by a person, the height information includes the height from the floor surface to the hand of the person and the height from the floor surface to the mounting position of the receiver 4. It is set in consideration and stored in the storage unit 42 in advance.

  Next, the group ID table will be described. The group ID table is a table in which the group ID is associated with the time interval between the first signal and the second signal described above. The group ID table is referred to by a signal analysis unit 43 to be described later, and identifies the group to which the transmitter 3 that transmitted the sound signal belongs from the time interval between the first signal and the second signal of the sound signal received by the receiver 4. Used to do. Hereinafter, the time interval associated with the group ID is referred to as “group time difference”.

  The group ID table according to the present embodiment includes a group ID “1” and a group time difference “1 ms”, a group ID “2” and a group time difference “2 ms”, a group ID “3” and a group time difference “3 ms”, and a group ID. “4” and the group time difference “4 ms” are associated with each other.

  Next, the transmission order ID table will be described. The transmission order ID table is a table in which the transmission order ID is associated with the time slot number of the acoustic signal received by the receiver 4. In the present embodiment, the signal analysis unit 43 described later divides the digital data input from the acoustic signal reception unit 41 into a plurality of time slots for analysis. Specifically, the signal analysis unit 43 monitors the SYNC signal included in the digital data. When the SYNC signal is detected, the signal analysis unit 43 divides the digital data at the interval of the signal transmission period T described above from the detection time of the SYNC signal. Signal analysis. This divided unit is defined as a time lot. For example, in the present embodiment, a time slot “1” is defined as a time slot “1” from a point in time when the signal transmission cycle T has elapsed from the position of the SYNC signal to a point in time from which the signal transmission cycle T has elapsed. A time slot “2” is defined from the end point to the time point at which the signal transmission period T elapses, and the time slot “9” is similarly divided to analyze the acoustic signal. As described above, after transmitting the SYNC signal, the transmitter 3 transmits acoustic signals in the order determined by the transmission order ID at intervals of the signal transmission period T. For this reason, the signal analysis unit 43 confirms the reception timing from the SYNC signal, that is, the time slot from which the SYNC signal is detected, and thereby the transmitter 3 that has transmitted the acoustic signal. Can be identified.

  The transmission order ID table in the present embodiment includes a transmission order ID “1” and a time slot “1”, a transmission order ID “2” and a time slot “2”, a transmission order ID “3”, and a time slot “3”. ”, Transmission order ID“ 4 ”and time slot“ 4 ”, transmission order ID“ 5 ”and time slot“ 5 ”, transmission order ID“ 6 ”and time slot“ 6 ”, transmission order ID“ 7 ”and time slot This is a table in which “7”, transmission order ID “8” and time slot “8”, transmission order ID “9”, and time slot “9” are associated with each other.

  Next, arrangement information will be described. The arrangement information is information indicating the arrangement of the transmitter 3 in the monitoring space. The arrangement information is referred to by a signal analysis unit 43 described later, and is used for measuring the position of the receiver 4. In the present embodiment, as the arrangement information, the transmission order ID of each transmitter 3, the group ID, the installation height from the floor surface, and the two-dimensional coordinates (X, Y) when the floor surface of the monitoring space is the XY plane. It is associated.

  Here, the arrangement of the transmitter 3 in the monitoring space will be described in detail. As described above, in the positioning system 1 of the present embodiment, the transmitters 3 having the same transmission order ID belonging to different groups simultaneously transmit acoustic signals to the monitoring space. For this reason, the transmitters 3 to which the same transmission order ID is assigned are installed at positions that are not adjacent to each other in the monitoring space and at a predetermined distance or more so that these simultaneously transmitted acoustic signals do not interfere with each other. .

  FIG. 6 is a diagram schematically showing the arrangement of the transmitter 3 in the present embodiment. In FIG. 6, a white circle indicates the position of the transmitter 3, and a number surrounded by a white circle corresponds to the transmission order ID of the transmitter 3. In addition, transmitters 3 to which the same group ID is assigned are shown surrounded by dotted lines. As shown in FIG. 6, the positioning system 1 in the present embodiment is composed of a total of 36 transmitters 3 and is divided into four groups composed of 9 transmitters 3. And the transmitter 3 with the same transmission order ID is arrange | positioned in the position which is not adjacent mutually, and the predetermined distance or more away. The positioning system 1 of the present invention arranges the transmitter 3 in this way, so that the acoustic signals transmitted simultaneously from the transmitter 3 do not interfere with each other.

  For example, as shown in FIG. 6, when the receiver 4 is present at the position of the black circle 4 a, compared to the position of the transmitter 3 to which the transmission order ID “1” of the group ID “1” is given, Transmitter 3 to which the transmission order ID “1” of the group ID “2” is assigned, Transmitter 3 to which the transmission order ID “1” of the group ID “3” is assigned, Transmission order ID “of the group ID“ 4 ” The transmitter 3 to which “1” is assigned has a long distance to the receiver 4. For this reason, even if these transmitters 3 transmit an acoustic signal at the same time, the receiver 4 first transmits the acoustic signal transmitted from the transmitter 3 to which the transmission order ID “1” of the group ID “1” is assigned. Then, the acoustic signal transmitted from the transmitter 3 to which the transmission order ID “1” of another group is assigned is received with a time difference and attenuation of the signal strength. That is, even if the transmitter 3 to which the transmission order ID “1” is assigned transmits the acoustic signal simultaneously to the monitoring space, the receiver 4 is installed near the receiver 4 from the reception timing and signal strength. It is possible to distinguish between the transmitter 3 and other transmitters 3. In addition, the predetermined distance is the reception waveform of the acoustic signal transmitted from the transmitter 3 located closest to the receiver 4 among the acoustic signals transmitted simultaneously, and the acoustic signal transmitted from the other transmitter 3. The received waveform may be a value that can be distinguished from the signal intensity by the receiver 4.

  When the receiver 4 exists at the position of the black circle 4b, the distance from the transmitter 3 to which the transmission order ID “1” of each group is assigned to the receiver 4 is substantially the same. In this case, since the acoustic signals transmitted simultaneously from the transmitter 3 to which the transmission order ID “1” is assigned are received at the receiver 4 with substantially the same and similar signal strength, it is possible to distinguish them. It becomes difficult. However, as shown in FIG. 6, in the positioning system 1 of the present invention, the transmitters 3 to which the same transmission order ID is assigned are installed at positions that are not adjacent to each other. Accordingly, even if the receiver 4 cannot distinguish the acoustic signal of the transmitter 3 to which the transmission order ID “1” is assigned, the transmitter 3 to which another transmission order ID is assigned, for example, shown in FIG. As described above, the acoustic signal transmitted from the transmitter 3 to which the transmission order IDs “5”, “6”, and “8” are assigned can be distinguished from the reception timing and the signal intensity. That is, the receiver 4 can measure the position of the receiver 4 based on these distinguishable acoustic signals.

  The arrangement of the transmitter 3 is not limited to the example described above. For example, in this embodiment, the transmitters 3 constituting the positioning system 1 are divided into four groups composed of nine transmitters 3. However, the number and groups of transmitters 3 constituting one group are divided. The number may be changed as appropriate in consideration of the monitoring purpose, the shape of the monitoring space, the area of the monitoring space, and the like. Further, the arrangement of the transmitters 3 may be different for each group.

  FIG. 7 is a diagram schematically illustrating another arrangement example of the transmitter 3. FIG. 7A shows an example in which the transmitters 3 constituting the positioning system 1 are divided into two groups composed of seven transmitters 3. FIG. 7B shows the positioning system 1. The example which divided | segmented the transmitter 3 to comprise into two groups comprised from the five transmitters 3 is shown. As shown in FIG. 7, the number of transmitters 3 constituting the group and the arrangement of the transmitters 3 for each group are different, but each transmitter 3 satisfies the above-described arrangement condition and is given the same transmission order ID. It can be seen that the transmitted transmitters are arranged at positions that are not adjacent to each other and at a predetermined distance or more. Although not shown, the number of transmitters 3 configured for each group may be varied. For example, the positioning system 1 may be realized by using seven transmitters 3 with the group ID “1” and five transmitters with the group ID “2”. Further, the transmitters 3 to which the same group ID is assigned as in the present embodiment may not be arranged so as to be gathered in the vicinity in the monitoring space. For example, the transmitters 3 may be arranged so that a plurality of transmitters 3 having different group IDs are adjacent to each other.

  The height information, the group ID table, the transmission order ID table, and the arrangement information of the transmitter 3 described above are stored in advance in the storage unit 32 of the receiver 4. However, the method by which the receiver 4 acquires these pieces of information is not particularly limited. For example, height information, a group ID table, a transmission order ID table, and arrangement information of the transmitter 3 are stored in advance in the storage unit 22 of the management device 2, and the receiver 4 receives these information via a communication network. May be acquired and stored in the storage unit 42.

  Next, returning to FIG. 5, the signal analysis unit 43 of the receiver 4 will be described.

  The signal analysis unit 43 includes at least one processor such as a CPU, DSP, MCU, and its peripheral circuits. The signal analysis unit 43 analyzes the acoustic signal received by the receiver 4 and measures the position of the receiver 4 in the monitoring space. Specifically, in this embodiment, the digital data input from the acoustic signal receiving unit 41 is divided into a plurality of time slots as described above, and each time slot is analyzed. In this embodiment, since the transmitter 3 transmits a signal obtained by modulating the baseband TSP into the ultrasonic band, the signal analysis unit 43 demodulates the input digital data to the baseband and then transmits the time slot. Analyze. In the present embodiment, since two types of frequency bands (main band and subband) are used, the signal analysis unit 43 demodulates the signal into a main band signal and a subband signal.

  The signal analysis unit 43 analyzes each time slot, and compares the signal strength of the pulse in the time slot, the time difference from the time slot start point in the main band to the predetermined pulse (first time difference), the predetermined pulse and subband of the main band The time difference (second time difference) between the predetermined pulses is calculated.

  Here, the analysis of the time slot will be described in detail with reference to FIGS. FIG. 8 is a diagram showing a reception waveform of the receiver 4 in the present embodiment. FIG. 9 is a diagram showing a received waveform in a time slot in the present embodiment.

  First, the signal analysis unit 43 detects a SYNC signal from the received waveform of the digital data input from the acoustic signal reception unit 41. Since the SYNC signal is a pulse signal of only the main band as described above, the signal analysis unit 43 detects a time point when the main band becomes equal to or higher than a predetermined intensity (hereinafter, SYNC intensity). Then, in the subband, when no signal exists within a predetermined time (for example, signal transmission cycle T) from the detection time, the detection time is set as the reception time of the SYNC signal. In FIG. 8, the time indicated by the arrow is the time when the SYNC signal is received.

  Then, when the SYNC signal is detected, the signal analysis unit 43, as shown in FIG. 8, performs signal transmission from the starting point with the time when the signal transmission period T has elapsed from the receiving point as the starting point of the time slot “1”. The time point at which the period T has elapsed is the end point of the time slot “1”. Thereafter, the end point of the time slot “1” is set as the starting point of the time slot “2”, and the time point when the signal transmission cycle L has elapsed from the starting point is set as the end point of the time slot “2”. Similarly, the same number of time slots as the number of transmission order IDs are defined. In FIG. 8, the time slots “4” to “9” are not shown.

  In FIG. 9, the received waveform of the time slot “1” shown in FIG. 8 is shown in an enlarged manner. The signal analysis unit 43 confirms the signal intensity of the pulse in the time slot, and first detects a time point when the pulse of the main band first becomes a predetermined intensity (first signal intensity) or more. Then, the signal analysis unit 43 obtains a time difference sn (n = 1 to 9) from the time slot start time point to the detected time point. This time is defined as a first time difference. S1 shown in FIG. 9 is the first time difference in the time slot “1”. As described above, the transmitter 3 of the positioning system 1 in the present embodiment has the same transmission order ID, and the transmitter 3 is installed at a position more than a predetermined distance. Can be regarded as the reception time of the direct wave of the first signal transmitted from the transmitter 3 closest to the receiver 4 among the transmitters 3 having the same transmission order ID. Note that the value of the first signal strength is the reception waveform of the first signal transmitted from the transmitter 3 existing closest to the receiver 4 in consideration of the distance between the transmitters 3 having the same transmission order ID. And the reception waveform of the first signal transmitted from the other transmitter 3 may be set in advance to values that can be distinguished by the receiver 4.

  Next, the signal analysis unit 43 confirms the signal intensity of the sub-band pulse in the time slot, and first detects a time when the intensity becomes equal to or higher than a predetermined intensity (second signal intensity). Then, the signal analysis unit 43 obtains a time difference dn (n = 1 to 9) from the time point when the main band pulse first becomes equal to or higher than the first signal intensity. This time difference is the second time difference. D1 shown in FIG. 9 is the second time difference in the time slot “1”. As described above, the transmitter 3 of the positioning system 1 according to the present embodiment is installed at a position separated by a predetermined distance or more because the transmitter 3 having the same transmission order ID is located within the time slot. Can be regarded as the reception time point of the direct wave of the second signal transmitted from the transmitter 3 closest to the receiver 4 among the transmitters 3 having the same transmission order ID. Note that the value of the second signal strength is the reception waveform of the second signal transmitted from the transmitter 3 existing closest to the receiver 4 in consideration of the distance between the transmitters 3 having the same transmission order ID. And the received waveform of the second signal transmitted from the other transmitter 3 may be set in advance to values that can be distinguished by the receiver 4.

  In the present embodiment, when obtaining the first time difference and the second time difference, the time when the pulse first becomes equal to or higher than the first signal strength or the time when the pulse first becomes equal to or higher than the second signal strength in the time slot. Using. However, it is not limited to this. For example, the first time difference and the second time difference may be obtained by using the reception time point of the pulse that appears first in the time slot without using the signal strength of the pulse. In this case, when the transmitter 3 is arranged, the distance (predetermined distance) between the transmitters 3 having the same transmission order ID is set to “the first signal and the second signal transmitted from the same transmitter 3 are always continuous. Thus, the distance may be such that the receiver 4 can receive the signal. In this case, the value of the predetermined distance may be appropriately determined in consideration of the maximum value of the time interval (group time difference) between the first signal and the second signal set for each group ID.

  After obtaining the first time difference and the second time difference for each time slot, the signal analysis unit 43 selects a plurality of time slots (effective time slots) used for positioning of the receiver 4 from the time slots. In the present embodiment, the signal analysis unit 43 selects three valid time slots. This is because the signal analysis unit 43 in the present embodiment measures the position of the receiver 4 based on the principle of triangulation, and the installation positions of the three transmitters 3 and the sound transmitted from the transmitter 3. This is because the time required for the signal to be received by the receiver (first time difference) is required for positioning. At this time, since three transmitters 3 used for positioning are preferably selected from those installed near the receiver 4, the signal analysis unit 43 sets the position of the receiver 4 as an effective time slot. A time slot in which an acoustic signal transmitted from the transmitter 3 installed near is included is selected. Therefore, in the present embodiment, time slots in which the first time difference in the time slot is short and the signal intensity of the pulse used for calculating the first time difference is equal to or greater than a predetermined intensity (effective intensity) are effective time slots. Select 3 as The pulse used for calculating the first time difference in the effective time slot corresponds to an example of “first received signal”.

  When selecting the effective time slot, the signal analysis unit 43 specifies the transmitter 3 that is the transmission source of the pulse used for calculating the first time difference for each effective time slot. First, the signal analysis unit 43 refers to the transmission order ID table stored in the storage unit 42 and identifies the transmission order ID of the transmitter 3 as the transmission source from the time slot number of the valid time slot. Here, as described above, the positioning system 1 according to the present embodiment is used for calculating the first time difference only by the time slot number because the transmitter 3 having the same transmission order ID transmits the acoustic signal at the same time. It cannot be determined which group the pulse belongs to the acoustic signal transmitted from the transmitter 3 belonging to. Therefore, the signal analysis unit 43 uses the second time difference to identify the group. Specifically, the signal analysis unit 43 refers to the group ID table stored in the storage unit 42, compares the group time difference of the table with the second time difference of the effective time slot, and associates it with the closest group time difference. The group ID being specified is specified. The signal analysis unit 43 specifies the transmitter 3 used for positioning from the transmission order ID and the group ID specified in this way. For example, in the diagram shown in FIG. 6, when the receiver 4 exists in 4a, first, time slots “1”, “2”, “4” are selected as effective time slots, and then transmitted from the time slot number. The order IDs “1”, “2”, and “4” are specified. Then, from the second time difference of each effective time slot, the transmitter 3 with the group ID “1” transmission order ID “1”, the transmitter 3 with the group “1” transmission order ID “2”, and the group ID “1”. The transmitter 3 having the transmission order ID “4” is specified as the transmitter 3 used for positioning. The sub-band pulse used for calculating the second time difference in the effective time slot corresponds to an example of “second received signal”.

  When the signal analysis unit 43 identifies the three transmitters 3 used for positioning, the height information of the receiver 4 stored in the storage unit 42 and the installation height and two-dimensional coordinates of the transmitter 3 included in the arrangement information are stored. The position of the receiver 4 is calculated based on the principle of triangulation using these information and the first time difference of each transmitter 3. That is, in the present embodiment, the position of the receiver 4 is measured as two-dimensional coordinates (X, Y) when the floor surface is the XY plane. In this embodiment, the position of the receiver 4 is measured using the principle of triangulation. However, the measurement method is not limited to this, and the transmitter 3 used for positioning is identified by the above-described method, What is necessary is just to measure the position of the receiver 4 using the position of the specified transmitter 3.

  After calculating the position of the receiver 4, the signal analysis unit 43 sequentially outputs the calculation results to the output unit 44.

  Next, returning to FIG. 5, the output unit 44 of the receiver 4 will be described.

  When the position of the receiver 4 is input from the signal analysis unit 43, the output unit 44 outputs the position to an external device. In the present embodiment, the measured position of the receiver 4 is displayed on a display device (not shown) such as a liquid crystal display. At this time, since the receiver 4 in the present embodiment is possessed or worn by a person, the output unit 44 possesses the position of the receiver 4 measured by the signal analysis unit 43. Display as the position of a person. The output destination and output method of the output unit 44 are not limited to this. For example, a communication unit (not shown) that communicates with an external device is provided in the receiver 4 so that the position of the receiver 4 (position of the person) measured by the signal analysis unit 43 is output via the communication network. It may be.

  In this embodiment, the storage unit 42, the signal analysis unit 43, and the output unit 44 are described as one of the configurations of the receiver 4. However, the storage unit 42, the signal analysis unit 43, and the output unit 44 are received. The positioning system 1 may be configured as a device different from the machine 4. In this case, the apparatus is connected to the receiver 4 through a communication network, and sequentially analyzes the digital data output from the acoustic signal receiver 41 of the receiver 4 to measure the position of the receiver 4. Good.

  In addition, as described above, when the third signal is increased as a signal constituting the acoustic signal in order to cover a wider monitoring space, the signal analysis unit 43, like the second time difference, By analyzing the frequency band to calculate the third time difference, and referring to the group ID table in the storage unit 42, the group ID associated with the time interval between the first signal and the third signal is specified. Good.

<System operation>
Hereinafter, the operation of the positioning system 1 in the present embodiment will be described. First, the synchronization signal transmission process of the management apparatus 2 will be described with reference to FIG. FIG. 10 is a flowchart of the synchronization signal transmission process in the present embodiment.

  When the positioning system 1 starts operating, first, the synchronization signal transmission unit 23 of the management device 2 transmits a synchronization signal to the plurality of transmitters 3 via the communication unit 21. At this time, the synchronization signal transmitter 23 starts measuring time (S101).

  Thereafter, the synchronization signal transmission unit 23 refers to the positioning cycle stored in the storage unit 22 and determines whether or not the positioning cycle has been reached (S102). When the positioning period is reached (S102, YES), the process proceeds to step S101, and a new synchronization signal is transmitted to the plurality of transmitters 3. At this time, the time measurement is reset and time measurement is started again. When the positioning cycle has not been reached (S102, NO), the transmission of the synchronization signal is waited until the positioning cycle is reached.

  Next, the acoustic signal transmission process of the transmitter 3 will be described with reference to FIG. FIG. 11 is a flowchart of the acoustic signal transmission process in the present embodiment.

  When the positioning system 1 starts operation, the transmission control unit 33 of the transmitter 3 generates digital data of the first signal and the second signal (S201). And the transmission control part 33 determines whether the synchronous signal was received from the management apparatus 2 via the communication part 31 (S202). When the synchronization signal is received (S202, YES), digital data of the SYNC signal is generated and output to the acoustic signal transmission unit 34. The acoustic signal transmission unit 34 that has received the input transmits a SYNC signal to the monitoring space (S203). When the synchronization signal is not received (S202, NO), the transmission of the SYNC signal is waited until the synchronization signal is received.

  When the transmission control unit 33 controls the transmission of the SYNC signal, the transmission control unit 33 starts timing and determines whether it is the transmission timing of the first signal (S204). Specifically, in the present embodiment, the signal transmission cycle “T” and the transmission order ID “i” stored in the storage unit 32 are referenced to determine whether or not the time T · i has elapsed. When the time T · i has passed (S204, YES), it is determined that the transmission timing of the first signal has come, and the generated digital data of the first signal is output to the acoustic signal transmission unit 34. The acoustic signal transmission unit 34 that has received the input transmits the first signal to the monitoring space (S205). When the time T · i has not elapsed (S204, NO), it is determined that it is not the transmission timing of the first signal, and the transmission of the first signal is waited until the time T · i has elapsed.

  When the transmission control unit 33 controls the transmission of the first signal, the transmission control unit 33 resets the time measurement and starts the time measurement again. Then, it is determined whether it is the transmission timing of the second signal (S206). Specifically, in the present embodiment, the group ID stored in the storage unit 32 is referred to and it is determined whether or not the time associated with the group ID (group time difference) has elapsed. When the group time difference has elapsed (S206, YES), it is determined that the transmission timing of the second signal has come, and the generated digital data of the second signal is output to the acoustic signal transmission unit 34. The acoustic signal transmission unit 34 that has received the input transmits the second signal to the monitoring space (S207). If the group time difference has not elapsed (S206, NO), it is determined that it is not the transmission timing of the second signal, and the transmission of the second signal is waited until the group time difference has elapsed. When controlling the transmission of the second signal, the transmission control unit 33 sets the time count to 0, returns to step S202, and waits until the synchronization signal is received again.

  Next, the positioning process of the receiver 4 will be described with reference to FIG. FIG. 12 is a flowchart of the positioning process in the present embodiment.

  When the receiver 4 starts operating, the acoustic signal receiver 41 collects sound in the monitoring space and sequentially outputs digital data to the signal analyzer 43. The signal analysis unit 43 determines whether or not the SYNC signal is included in the input digital data (S301, S302). When the SYNC signal is detected (S302, YES), the time slot is divided by the number of transmission order IDs by referring to the signal transmission cycle and transmission order ID table in the storage unit 42 (S303). If the SYNC signal is not detected (S302, NO), the process returns to step S301, and the SYNC signal detection process is repeated until the SYNC signal is detected.

  When dividing the time slot, the signal analysis unit 43 performs the processing from step S305 to step S306 for each time slot. When Steps S305 to S306 are completed for all time slots, the process proceeds to Step S308 (S304, S307). The signal analysis unit 43 analyzes the signal for the time slot to be processed and calculates a first time difference (S305). Thereafter, the signal is analyzed for the time slot to be processed, and the second time difference is calculated (S306).

  When the signal analysis unit 43 calculates the first time difference and the second time difference for all the time slots, the signal analysis unit 43 selects a predetermined number of effective time slots from the time slots. In the present embodiment, three valid time lots are selected (S308).

  When the selection of the valid time slot is completed, the signal analysis unit 43 refers to the transmission order ID table in the storage unit 42 and identifies the transmission order ID corresponding to the time slot number for each valid time slot. Thereafter, the group ID table in the storage unit 42 is referred to, and for each effective time slot, the group time difference stored in the group ID table is compared with the second time difference to identify the group ID. The signal analysis unit 43 identifies the transmitter 3 used for positioning based on the identified transmission order ID and group ID. Then, the signal analysis unit 43 refers to the arrangement information stored in the storage unit 42 and acquires the specified installation height and two-dimensional coordinates of the transmitter 3. The signal analysis unit 43 measures the position of the receiver 4 based on the height information stored in the storage unit 42, the specified installation height and two-dimensional coordinates of the transmitter 3, and the first time difference of each effective time slot. . The signal analysis unit 43 outputs the measured position information to the output unit 44 (S309).

  When receiving the position of the receiver 4 from the signal analysis unit 43, the output unit 44 outputs the position to the outside as the position of the person who owns the receiver 4. In the present embodiment, the position of the person is displayed on the display device (S310). When the output process is completed, the process returns to step S301, and the SYNC signal detection process is repeated until the SYNC signal is detected again.

  As described above, according to the positioning system 1 in the present embodiment, even if the number of transmitters 3 constituting the system is increased, the time required for all the transmitters 3 to finish transmitting acoustic signals, that is, The time required for measuring the position of the receiver 4 can be kept short. For this reason, even if the monitoring space is a wide area, the position of the receiver 4 that moves in the monitoring space, that is, the position of the moving object can be accurately measured.

DESCRIPTION OF SYMBOLS 1 Positioning system, 2 Management apparatus, 3 Transmitter, 4 Receiver, 5 Person, 6 area | region, 21 Communication part, 22 Storage part, 23 Synchronization signal transmission part, 31 Communication part, 32 Storage part, 33 Transmission control part, 34 Acoustic signal transmission unit, 41 Acoustic signal reception unit, 42 Storage unit, 43 Signal analysis unit, 44 Output unit

Claims (2)

A positioning system for measuring the position of a receiver in a monitoring space,
Each of the first acoustic signals is arranged in a predetermined installation position in the monitoring space, and is transmitted in a transmission order that is unique and overlapped between the groups to which the own device belongs. A plurality of transmitters for transmitting a second acoustic signal at a group time difference specific to the group to which the own device belongs from transmission;
A receiver for receiving the first acoustic signal and the second acoustic signal;
A storage unit storing the installation position of each of the plurality of transmitters, the transmission order, and the group time difference;
The first acoustic signal and the second acoustic signal having a predetermined intensity or more received by the receiver are detected as a first reception signal and a second reception signal, respectively, and the reception order of the first reception signal and the first reception signal The transmission time of the first reception signal is identified by comparing the time difference between the second reception signal and the second reception signal with the transmission order and the group time difference stored in the storage unit, and stored in the storage unit A signal analysis unit for measuring the position of the receiver from the installation position of the transmission source;
With
The plurality of transmitters may receive the first reception from a transmitter having the same transmission order as the transmission source at a position in the monitoring space where the first reception signal from any of the transmission sources is detected. A positioning system, wherein transmitters having the same transmission order are spaced apart by a distance where no signal is detected. The positioning system according to claim 1,
Each of the plurality of transmitters transmits the first acoustic signal and the second acoustic signal in different frequency bands from each other.

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