JPWO2016020960A1 - Position detection system and position detection method - Google Patents

Abstract

The position detection system includes a transmitter (104) that is held by each of a plurality of moving bodies and wirelessly transmits a detection signal (151), and a plurality of receivers that receive the detection signal (151). Each of the transmitters (104) wirelessly transmits the detection signal (151) at a first interval in the first mode, and transmits the detection signal (151) in a second mode shorter than the first interval in the second mode. When wireless transmission is performed at intervals and the mode switching signal (152) is received, the operation mode is switched from the first mode to the second mode.

Description

  The present invention relates to a position detection system for detecting the position of a moving body.

  As a lost child search system for searching for lost children, a signal periodically transmitted from a transmitter such as a wireless IC tag carried by the monitoring subject is received by a receiver such as an IC tag reader installed in the facility. A method for detecting a lost child is known (for example, see Patent Document 1).

JP 2011-76242 A

  However, when such a lost child search system is used in an amusement park or the like where the number of monitoring subjects (for example, children) is very large, the number of signals transmitted from the transmitter increases, and wireless signal congestion occurs. There is.

  Further, in such a position detection system such as a lost child search system, it is desired that the usage time during battery driving can be extended by reducing the power consumption of the transmitter.

  Then, an object of this invention is to provide the position detection system which can suppress the congestion of a radio signal and can reduce the power consumption of a transmitter.

  In order to achieve the above object, a position detection system according to an aspect of the present invention is a position detection system for detecting the position of a moving body, and is held by each of the plurality of moving bodies and receives a detection signal. The transmitter includes a transmitter that wirelessly transmits and a plurality of receivers that receive the detection signal, and the position detection system is the transmitter that is held by a target moving body among the plurality of moving bodies. The designation of the target transmitter is accepted, the operation mode of the transmitter is changed from the first mode in which the detection signal is wirelessly transmitted at a first interval, and the detection signal is wirelessly transmitted at a second interval shorter than the first interval. A first mode switching signal for switching to the second mode to be transmitted is wirelessly transmitted to the target transmitter, and when the target transmitter receives the first mode switching signal, the operation mode is changed to the first mode. From one mode to the above The position detection system further switches the position of the target transmitter based on which of the plurality of receivers has received the detection signal from the target transmitter. Generate information to show.

  According to this configuration, when the target transmitter held by the target mobile body is instructed, the target transmitter transmits the detection signal at short intervals. Thereby, the position of the target transmitter can be detected with high accuracy. Moreover, by setting the transmission interval of the detection signal of the transmitters other than the target transmitter to be long, it is possible to suppress radio signal congestion and reduce the power consumption of the transmitter.

  For example, when the receiver receives the detection signal from the target transmitter, the receiver wirelessly transmits the first mode switching signal to the target transmitter, and the transmitter can receive a radio signal. An operation state that is a state and a standby state in which a wireless signal cannot be received, and the operation state is established during a predetermined period after the detection signal is transmitted in the first mode. The first mode switching signal may be received.

  According to this configuration, the transmitter transits to an operation state in which a radio signal can be received in a predetermined period after transmitting the detection signal. Thereby, the power consumption of a transmitter can be reduced. Further, the receiver transmits a first mode switching signal triggered by reception of the detection signal. As a result, it is possible to prevent an unnecessary first mode switching signal from being transmitted from the receiver, thereby reducing power consumption of the receiver and reducing congestion of radio signals.

  For example, the position detection system includes a management device that generates the information indicating the position of the target transmitter, and the receiver receives the detection signal from the target transmitter among the plurality of transmitters. A notification signal indicating that the detection signal from the target transmitter has been received is wirelessly transmitted to the management device, and the detection is performed from a transmitter other than the target transmitter among the plurality of transmitters. When receiving a signal for use, it is not necessary to wirelessly transmit a signal indicating that the signal for detection has been received from the transmitter to the management device.

  According to this configuration, only the notification signal for the detection signal transmitted from the target transmitter is transmitted to the management device, and the notification signal for the detection signal transmitted from a transmitter other than the target transmitter is transmitted to the management device. Not. Thereby, since the number of notification signals transmitted can be suppressed, congestion of radio signals can be suppressed.

  For example, the position detection system accepts designation of a plurality of target transmitters, wirelessly transmits the first mode switching signal to the plurality of target transmitters, and the plurality of target transmitters are in the first mode. When the switching signal is received, the operation mode is switched from the first mode to the second mode, and the plurality of target transmitters wirelessly transmit the detection signals at different timings in the second mode. May be.

  According to this configuration, it is possible to reduce congestion of radio signals when a plurality of transmitters operate in the second mode.

  For example, the position detection system wirelessly transmits timing information indicating different transmission timings to the plurality of target transmitters, and the plurality of target transmitters are based on the transmission timings indicated by the received timing information, The detection signal may be transmitted wirelessly at different timings.

  According to this configuration, it is possible to change the transmission timing of detection signals by a plurality of transmitters at an arbitrary timing.

  For example, the position detection system may determine a plurality of transmission timings using reception times at which the receiver has received the plurality of detection signals transmitted from the plurality of target transmitters.

  According to this configuration, the transmission timings of the detection signals by the plurality of transmitters can be varied without synchronizing the plurality of transmitters.

  For example, each of the plurality of target transmitters may transmit the detection signal when receiving the detection signal transmitted from another target transmitter.

  According to this configuration, the transmission timings of the detection signals by the plurality of transmitters can be varied without synchronizing the plurality of transmitters.

  For example, the position detection system transmits, to the target transmitter, switching time information for designating a switching time for switching the operation mode from the first mode to the second mode. The operation mode may be switched from the first mode to the second mode at the switching time after receiving the first mode switching signal.

  According to this configuration, the operation mode of the transmitter can be changed at an arbitrary timing.

  For example, the position detection system transmits, to the receiver, switching time information for designating a switching time for switching the operation mode from the first mode to the second mode, and the receiver At the time, the first mode switching signal may be wirelessly transmitted to the target transmitter.

  According to this configuration, the operation mode of the transmitter can be changed at an arbitrary timing.

  For example, the position detection system further includes a second mode switching signal for switching the operation mode of the transmitter from the first mode or the second mode to a third mode that does not transmit the detection signal. Wirelessly transmitting to the target transmitter, and the target transmitter may switch the operation mode from the first mode or the second mode to the third mode when receiving the second mode switching signal. Good.

  According to this configuration, it is possible to further suppress congestion of radio signals and further reduce power consumption of the transmitter.

  A position detection system according to one embodiment of the present invention is a position detection system for detecting the position of a moving body, and is held by each of the plurality of moving bodies, and a transmitter that wirelessly transmits a detection signal. A plurality of receivers for receiving the detection signals, wherein the position detection system wirelessly transmits an operation mode of a target transmitter which is one of the plurality of transmitters at a first interval. Acquiring first switching time information for designating a first switching time for switching to the second mode in which the detection signal is wirelessly transmitted at a second interval shorter than the first interval from the first mode to be transmitted; The target transmitter switches the operation mode from the first mode to the second mode at the first switching time, and the position detection system further includes any one of the plurality of receivers. The target transmission Based on the one detection signal is received from, generates information indicating the position of said target transmitter.

  According to this configuration, the target transmitter transmits the detection signal at short intervals after the instructed switching time. Thereby, the position of the target transmitter can be detected with high accuracy. Moreover, by setting the transmission interval of the detection signal of the transmitters other than the target transmitter to be long, it is possible to suppress radio signal congestion and reduce the power consumption of the transmitter.

  For example, the position detection system further specifies a second switching time for switching the operation mode of the target transmitter from the first mode or the second mode to a third mode in which the detection signal is not transmitted. The second transmitter time information is acquired, and the target transmitter may switch the operation mode from the first mode or the second mode to the third mode at the second switch time.

  According to this configuration, it is possible to further suppress congestion of radio signals and further reduce power consumption of the transmitter.

  In addition, a position detection method according to an aspect of the present invention includes a transmitter that is held by each of a plurality of moving bodies and that wirelessly transmits a detection signal, and a plurality of receivers that receive the detection signal. A position detection method in a detection system, comprising: an accepting step of accepting designation of a target transmitter that is the transmitter held by a target mobile body among the plurality of mobile bodies; and an operation mode of the transmitter A first mode switching signal for switching from the first mode in which the detection signal is wirelessly transmitted at a first interval to the second mode in which the detection signal is wirelessly transmitted at a second interval shorter than the first interval. Wirelessly transmitting to the target transmitter, and when the target transmitter receives the first mode switching signal, the operation mode of the target transmitter is changed from the first mode to the second mode. A transmission interval control step for switching and information indicating the position of the target transmitter is generated based on which of the plurality of receivers has received the detection signal from the target transmitter. Information generating step.

  According to this, when the target transmitter held by the target mobile body is instructed, the target transmitter transmits the detection signal at short intervals. Thereby, the position of the target transmitter can be detected with high accuracy. Moreover, by setting the transmission interval of the detection signal of the transmitters other than the target transmitter to be long, it is possible to suppress radio signal congestion and reduce the power consumption of the transmitter.

  In addition, a position detection method according to an aspect of the present invention includes a transmitter that is held by each of a plurality of moving bodies and that wirelessly transmits a detection signal, and a plurality of receivers that receive the detection signal. A position detection method in a detection system, wherein an operation mode of a target transmitter that is one of a plurality of transmitters is changed from a first mode in which the detection signal is wirelessly transmitted at a first interval. An acquisition step of acquiring first switching time information for designating a first switching time for switching to a second mode in which radio transmission is performed at a second interval shorter than the first interval; and the target transmitter includes the first switching At a time, a transmission interval control step for switching the operation mode from the first mode to the second mode, and at any one of the plurality of receivers, the detection signal from the target transmitter is received. The Based on Taka, including an information generation step of generating information indicating a position of the target transmitter.

  According to this, after the instructed switching time, the target transmitter transmits the detection signal at short intervals. Thereby, the position of the target transmitter can be detected with high accuracy. Moreover, by setting the transmission interval of the detection signal of the transmitters other than the target transmitter to be long, it is possible to suppress radio signal congestion and reduce the power consumption of the transmitter.

  Note that these comprehensive or specific aspects may be realized by a system, a method, an integrated circuit, a computer program, or a recording medium such as a computer-readable CD-ROM, and the system, method, integrated circuit, and computer program. Also, any combination of recording media may be realized.

  INDUSTRIAL APPLICABILITY The present invention can provide a position detection system that can suppress congestion of radio signals and reduce power consumption of a transmitter.

FIG. 1 is a diagram illustrating a configuration of a lost child search system according to an embodiment. FIG. 2 is a block diagram of the transmitter according to the embodiment. FIG. 3 is a block diagram of a receiver according to the embodiment. FIG. 4 is a block diagram of the management apparatus according to the embodiment. FIG. 5 is a diagram illustrating an operation of the lost child search system according to the embodiment. FIG. 6 is a diagram illustrating a configuration of a detection signal according to the embodiment. FIG. 7 is a diagram illustrating a configuration of a lost child designation signal according to the embodiment. FIG. 8 is a diagram illustrating the transmission interval of the detection signal in each mode according to the embodiment. FIG. 9 is a diagram illustrating transition of the wireless reception state in the transmitter according to the embodiment. FIG. 10 is a diagram illustrating a configuration of a notification signal according to the embodiment. FIG. 11 is a diagram illustrating a state in which a detection signal is wirelessly transmitted by the transmitter according to the embodiment. FIG. 12 is a diagram illustrating a display example of lost child information according to the embodiment. FIG. 13 is a flowchart illustrating the operation of the management apparatus according to the embodiment. FIG. 14 is a flowchart illustrating the operation of the receiver according to the embodiment. FIG. 15 is a flowchart showing the operation of the transmitter according to the embodiment. FIG. 16 is a diagram illustrating the transmission timing of the detection signal according to the embodiment. FIG. 17 is a diagram illustrating a delay time setting operation by the position detection system according to the embodiment. FIG. 18 is a diagram illustrating a mode switching operation by the position detection system according to the embodiment. FIG. 19 is a diagram illustrating a configuration of a designation signal according to the embodiment.

  Hereinafter, embodiments will be specifically described with reference to the drawings.

  Note that each of the embodiments described below shows a specific example of the present invention. The numerical values, shapes, materials, constituent elements, arrangement positions and connecting forms of the constituent elements, steps, order of steps, and the like shown in the following embodiments are merely examples, and are not intended to limit the present invention. In addition, among the constituent elements in the following embodiments, constituent elements that are not described in the independent claims indicating the highest concept are described as optional constituent elements.

  In the lost child search system according to the present embodiment, the transmitter has a normal mode (first mode) and a search mode (second mode) in which the transmission interval of detection signals is shorter than that in the normal mode. Furthermore, when a lost child occurs, only the transmitter carried by the lost child is set to the search mode. Thereby, the said lost child search system can reduce the power consumption of a transmitter while suppressing the congestion of a radio signal.

  First, the configuration of the lost child search system according to the present embodiment will be described.

  FIG. 1 is a diagram showing a configuration of a lost child search system 100 according to the present embodiment.

  The lost child search system 100 shown in FIG. 1 is used in facilities such as an amusement park or a theme park, for example. The lost child search system 100 is a system for searching for lost children, and includes a management device 102, a plurality of receivers 103, and a plurality of transmitters 104.

  Each of the plurality of transmitters 104 is carried by a monitoring subject (for example, a child). For example, when entering amusement park or the like, the transmitter 104 is attached to the body or personal belongings of the person to be monitored. Specifically, the transmitter 104 is a bracelet type (watch type) worn on the arm of the monitoring subject or a necklace type hung around the neck of the monitoring subject. Alternatively, the transmitter 104 may be a name tag type or the like.

  The transmitter 104 periodically transmits a detection signal 151 by radio. The radio signal used in this radio transmission is, for example, a radio signal conforming to IEEE 802.15.4, for example, a 2.4 GHz band, a 920 MHz band, or a 950 MHz band radio signal. That is, the radio signal used in the lost child search system 100 is a radio signal having a relatively narrow radio communication range (for example, about 200 to 300 m). Note that other wireless signals such as Bluetooth (registered trademark) may be used.

  The plurality of receivers 103 are arranged in the facility and receive detection signals 151 periodically transmitted from the transmitter 104. It should be noted that at least a part of the plurality of receivers 103 may be carried by a supervisor (for example, facility staff) or the like.

  When receiving the detection signal 151, the receiver 103 notifies the management apparatus 102 that the detection signal 151 has been detected. Specifically, the receiver 103 transmits a notification signal 153 indicating that the detection signal 151 has been detected to the management apparatus 102.

  The management apparatus 102 is, for example, a PC (personal computer) installed in a facility. The management apparatus 102 receives the notification signal 153 transmitted from the receiver 103, and detects the position of the monitoring target person using information included in the notification signal 153. In addition, the management apparatus 102 displays lost child information indicating the position of the monitoring target person (lost child).

  Hereinafter, the configuration of each apparatus will be described. First, the configuration of the transmitter 104 will be described.

  FIG. 2 is a block diagram showing the configuration of the transmitter 104. The transmitter 104 includes a wireless transmission unit 111, a wireless reception unit 112, a transmission interval control unit 113, and a power supply unit 114.

  The wireless transmission unit 111 periodically wirelessly transmits the detection signal 151. The wireless transmission unit 111 has a normal mode and a search mode. The wireless transmission unit 111 wirelessly transmits the detection signal 151 at a first interval in the normal mode, and wirelessly transmits the detection signal 151 at a second interval shorter than the first interval in the search mode.

  The wireless reception unit 112 receives the mode switching signal 152 wirelessly transmitted from the receiver 103.

  The transmission interval control unit 113 switches the operation mode (normal mode and search mode) of the wireless transmission unit 111 according to the mode switching signal 152.

  The power supply unit 114 is a power supply that supplies power to the transmitter 104, and is, for example, a battery or a battery. That is, the transmitter 104 can be operated only by power supply from the inside (or power generated inside) without receiving power supply from the outside.

  Next, the configuration of the receiver 103 will be described.

  FIG. 3 is a block diagram illustrating a configuration of the receiver 103. The receiver 103 includes a communication unit 121, a lost child setting control unit 122, a lost child transmitter storage unit 123, a wireless transmission unit 124, a wireless reception unit 125, a reception intensity measurement unit 126, a position measurement unit 127, A notification signal generation unit 128 and a relay unit 129 are provided.

  The communication unit 121 communicates with the management apparatus 102. For example, the plurality of receivers 103 form a wireless network, and the plurality of receivers 103 include a parent device and a child device (relay device). A signal wirelessly transmitted from the slave unit is transmitted to the master unit directly or via one or more slave units. The parent device that has received the signal transmits the signal to the management apparatus 102 via the network. Note that the frequency band and communication method of the wireless signal used in this wireless network may be the same as or different from the frequency band and communication method of the detection signal 151. Further, the communication method between the receiver 103 and the management apparatus 102 may be wireless communication not via a repeater, or a wired connection may be used for a part or all of it. For example, the receiver 103 and the management apparatus 102 may be connected via the Internet or Wi-Fi (registered trademark).

  The communication unit 121 receives the lost child designation signal 154 transmitted from the management device 102 and indicating the lost child transmitter (search target transmitter) that is the transmitter 104 carried by the lost child. In addition, the communication unit 121 transmits a notification signal 153 to the management apparatus 102.

  The lost child setting control unit 122 registers a lost child transmitter based on the lost child designation signal 154. Specifically, the lost child setting control unit 122 stores information for specifying the lost child transmitter in the lost child transmitter storage unit 123.

  The wireless transmission unit 124 wirelessly transmits a mode switching signal 152 to the lost child transmitter based on the control of the lost child setting control unit 122.

  The wireless reception unit 125 receives the detection signal 151 wirelessly transmitted from the transmitter 104.

  The reception intensity measurement unit 126 measures the reception radio wave intensity of the radio signal received by the radio reception unit 125.

  The position measuring unit 127 measures the position where the receiver 103 is arranged. For example, the position measurement unit 127 has a GPS (Global Positioning System) function, and measures the position where the receiver 103 is disposed using the GPS function. Note that the receiver 103 may not include the position measurement unit 127.

  The notification signal generation unit 128 generates a notification signal 153 when the wireless reception unit 125 receives the detection signal 151 from the lost child transmitter. This notification signal 153 is transmitted to the management apparatus 102 by the communication unit 121.

  The relay unit 129 performs processing for relaying the notification signal 153 and the lost child designation signal 154 transmitted from the other receivers 103 to the management apparatus 102.

  Note that not all of the plurality of receivers 103 need to have all of the above functions. For example, there may be a device having only a relay function. Further, the function of the receiver 103 may be realized by a plurality of devices obtained by dividing the function by function or signal processing.

  Here, the communication unit 121, the wireless transmission unit 124, and the wireless reception unit 125 are individually described. However, the communication between the management apparatus 102 and the receiver 103, and the communication between the receiver 103 and the transmitter 104 are described. When the same wireless communication method is used for communication, the communication unit 121, the wireless transmission unit 124, and the wireless reception unit 125 may be realized by a single processing unit.

  Next, the configuration of the management apparatus 102 will be described.

  FIG. 4 is a block diagram illustrating a configuration of the management apparatus 102. The management apparatus 102 includes a reception unit 131, a lost child designation unit 132, a communication unit 133, a receiver position storage unit 134, a lost child information generation unit 135, and a display unit 136.

  The accepting unit 131 accepts information for specifying a lost child receiver designated by a user operation or the like.

  The lost child designation unit 132 generates a lost child designation signal 154 for designating the lost child receiver received by the reception unit 131.

  The communication unit 133 communicates with the plurality of receivers 103. Specifically, the communication unit 133 transmits the lost child designation signal 154 to the plurality of receivers 103. Further, the communication unit 133 receives the notification signal 153 transmitted from the receiver 103.

  The receiver position storage unit 134 stores the positions of the plurality of receivers 103. For example, the receiver position storage unit 134 includes information indicating the position of the receiver 103 included in the notification signal 153 transmitted from the receiver 103 or the position of the receiver 103 transmitted in advance from the receiver 103. Is stored. The receiver position storage unit 134 may store information indicating the positions of the plurality of receivers 103 input in advance by a user operation or the like.

  The lost child information generation unit 135 generates lost child information indicating the position of the lost child transmitter by using the information included in the notification signal 153 and the position information of the receiver 103 that is the transmission source of the notification signal 153.

  The display unit 136 displays lost child information.

  The configuration of the lost child search system 100 is not limited to the configuration shown in FIG.

  For example, a plurality of management devices 102 may exist. Also, some of the plurality of management devices 102 may be mobile terminals (for example, smartphones) carried by facility staff or guardians. For example, the function of the management apparatus 102 may be realized by a guardian installing an application (application program) on a smartphone.

  Further, the function of the management apparatus 102 may be realized by a plurality of devices. For example, a part of the function of the management apparatus 102 may be realized by a PC installed in a facility, and the other part may be realized by a smartphone carried by a guardian. Specifically, the lost child information is generated by a device (for example, a PC), and the generated lost child information is transmitted to another device (for example, a smartphone) via a network or the like. It may be displayed.

  In the above description, the receiver 103 and the management apparatus 102 are individually described. However, the receiver 103 and the management apparatus 102 may be configured as a single apparatus. In other words, at least one of the receivers 103 may have at least part of the function of the management apparatus 102, or the management apparatus 102 may have at least part of the function of the receiver 103.

  For example, a smartphone carried by a staff member or guardian may have both functions of the management device 102 and the receiver 103. For example, the functions of the management device 102 and the receiver 103 may be realized by connecting an external device to a smartphone and installing an application on the smartphone. In this case, the external device includes, for example, a wireless transmission unit 124, a wireless reception unit 125, and a reception intensity measurement unit 126 included in the receiver 103. The external device may include functions other than these. In addition, the application may be stored in an external device or acquired via a network. Moreover, an application may be automatically installed in a smart phone by attaching an external device to the smart phone.

  When the management device 102 and the receiver 103 are realized as a single device, signal transmission between the management device 102 and the receiver 103 is performed within the device. In other words, the transmission of the notification signal 153 and the lost child designation signal 154 described above includes not only transmission between devices via a network or the like but also transmission of signals within the device.

  In addition, when entering an amusement park or the like, a guardian may pre-install an external device on his / her smartphone and install an application. Thereby, when the guardian loses sight of the monitoring subject (child), he / she can immediately display the position of the monitoring subject on the smartphone by operating the smartphone.

  Further, the external device is associated with a specific transmitter 104, and the associated external device and transmitter 104 may be distributed to a guardian. In this case, only the positional information of the associated transmitter 104 is displayed from the smartphone to which the external device is attached. As a result, an operation for designating the transmitter 104 is not necessary, and the operation on the smartphone can be simplified.

  In addition, the management apparatus 102 may have a function of setting information on the transmitter 104 or the receiver 103, a function of setting a transmission interval, and the like.

  Hereinafter, the operation of the lost child search system 100 will be described.

  FIG. 5 is a diagram illustrating operations performed by the lost child search system 100. Here, for simplification of description, operations of one management apparatus 102, two receivers 103A and 103B, and one transmitter 104 will be described.

  In the initial state, the transmitter 104 is set to the normal mode (S101). In the normal mode, the transmitter 104 transmits the detection signal 151 at a relatively long interval (for example, every one minute) (S102).

  FIG. 6 is a diagram illustrating a configuration of the detection signal 151. As shown in FIG. 6, the detection signal 151 includes a transmitter ID 161 </ b> A for identifying the transmitter 104 that is the transmission source of the detection signal 151.

  Here, it is assumed that a lost child has occurred. Information specifying the lost child transmitter carried by the lost child is input to the management apparatus 102 by the user. For example, a transmitter ID unique to the transmitter 104 is input to the management apparatus 102 (S103).

  The management apparatus 102 transmits a lost child designation signal 154 that identifies the input lost child transmitter to the plurality of receivers 103A and 103B (S104). FIG. 7 is a diagram showing the configuration of the lost child designation signal 154. As shown in FIG. As shown in FIG. 7, for example, the lost child designation signal 154 includes a transmitter ID 161B of the lost child transmitter.

  The receivers 103A and 103B that have received the lost child designation signal 154 register the lost child transmitter designated by the lost child designation signal 154 (S105). Specifically, the receivers 103 </ b> A and 103 </ b> B retain the transmitter ID 161 </ b> B of the lost child transmitter included in the lost child designation signal 154 in the lost child transmitter storage unit 123.

  In a state where the lost child transmitter is registered, the detection signal 151 transmitted from the registered lost child transmitter is received in any of the plurality of receivers 103 (S106). For example, in the example of FIG. 5, a lost child transmitter exists near the receiver 103B, and the detection signal 151 is received by the receiver 103B.

  The receiver 103B that has received the detection signal 151 from the lost child transmitter transmits a mode switching signal 152 to the lost child transmitter (S107).

  The lost child transmitter that has received the mode switching signal 152 switches the operation mode from the normal mode to the search mode (S108). In the search mode, the transmitter 104 transmits the detection signal 151 at short intervals (for example, every 5 seconds) (S109).

  FIG. 8 is a diagram illustrating transmission intervals of the detection signal 151 in the normal mode and the search mode. As shown in FIG. 8, in the normal mode, the transmitter 104 transmits a detection signal 151 at an interval T1. In the search mode, the transmitter 104 transmits the detection signal 151 at an interval T2 shorter than the interval T1. For example, the interval T2 is less than or equal to half of the interval T1. The interval T2 may be 1/10 or less of the interval T1.

  Although FIG. 8 shows a case where the interval T1 in the normal mode is constant, the interval T1 is not constant and may be changed periodically or randomly. Thereby, it can suppress that the signal 151 for a detection is simultaneously transmitted from the some transmitter 104. FIG. Similarly, the interval T2 in the search mode may not be constant.

  Further, the transmitter 104 may have a function of switching the frequency band of the detection signal 151. In this case, the radio signal congestion can be reduced by setting the frequency bands used by the plurality of transmitters 104 to different bands.

  FIG. 9 is a diagram illustrating transition of a radio signal reception state in the transmitter 104. The transmitter 104 has an operation state in which a radio signal can be received and a standby state in which a radio signal cannot be received. In the standby state, the power consumption of the transmitter 104 is lower than that in the operating state. As shown in FIG. 9, the transmitter 104 is in an operating state during a predetermined period T3 after transmitting the detection signal 151 in the normal mode, and is in a standby state during other periods. For example, the length of the period T3 is 100 milliseconds.

  In this period T3, the mode switching signal 152 is transmitted from the receiver 103B, and the transmitter 104 receives the mode switching signal 152.

  Note that the same operation may be performed in the search mode.

  As described above, the transmitter 104 changes to an operation state in which a radio signal can be received only in a period immediately after the detection signal 151 is transmitted. Thereby, the power consumption of the transmitter 104 can be reduced. The receiver 103B transmits a mode switching signal 152 triggered by the reception of the detection signal 151. Thereby, it is possible to prevent the unnecessary mode switching signal 152 from being transmitted from the receiver 103B, so that the power consumption of the receiver 103B can be reduced and the congestion of the radio signal can be reduced.

  Note that the mode switching signal 152 may be transmitted and received by a method other than the above. For example, the transmitter 104 may always operate in an operating state. Alternatively, the transmitter 104 periodically transitions to the operating state, and the receiver 103B continuously transmits the mode switching signal 152 until the transmitter 104 transitions to the operating state and receives the mode switching signal 152. Also good. However, in such a case, since a plurality of receivers 103 need to continuously transmit the mode switching signal 152, congestion of radio signals occurs. On the other hand, by using the above method, transmission of such an unnecessary mode switching signal 152 can be suppressed.

  The receiver 103B that has received the detection signal 151 in step S106 transmits a notification signal 153 to the management apparatus 102 (S110). FIG. 10 is a diagram illustrating a configuration of the notification signal 153. As shown in FIG. 10, the notification signal 153 includes a receiver ID 162, a transmitter ID 161 </ b> C, received radio wave intensity information 163, and receiver position information 164.

  The receiver ID 162 is the receiver 103 that has received the detection signal 151 and indicates the receiver 103 that has transmitted the notification signal 153.

  The transmitter ID 161C indicates the transmitter 104 that is the transmission source of the detection signal 151.

  The received radio wave intensity information 163 indicates the received radio wave intensity of the detection signal 151 received by the receiver 103B.

  The receiver position information 164 indicates the current position of the receiver 103B. For example, when the receiver 103B is a smartphone or the like, the receiver position information 164 is the position information of the receiver 103B measured by the GPS or the like that the smartphone has. When the receiver 103B is a stationary device, the receiver position information 164 may not be included in the notification signal 153.

  Note that the notification signal 153 may include information other than the above. For example, the notification signal 153 may include information indicating the time when the detection signal 151 is received.

  The management apparatus 102 that has received the notification signal 153 uses the information included in the notification signal 153 to generate lost child information indicating the position of the lost child transmitter, and displays the lost child information (S111).

  FIG. 11 is a diagram illustrating a state where the detection signal 151 is wirelessly transmitted by the transmitter 104. As shown in FIG. 11, only the receiver 103 arranged within a predetermined range (within the wireless communication range of the transmitter 104) from the transmitter 104 among the plurality of receivers 103 receives the detection signal 151. In the example shown in FIG. 5, the detection signal 151 is received only by the receiver 103B, but may be received by a plurality of receivers 103A to 103D as shown in FIG. In this case, each of the plurality of receivers 103 </ b> A to 103 </ b> D transmits a notification signal 153 to the management apparatus 102. The management apparatus 102 generates lost child information using the plurality of notification signals 153.

  The lost child information generation unit 135 included in the management apparatus 102 generates lost child information indicating the position of the transmitter 104 using one or more notification signals 153 received by the communication unit 133. Specifically, the lost child information generation unit 135 uses the received radio wave intensity of the detection signal 151 in the receiver 103 indicated by the received radio wave intensity information 163 included in the notification signal 153 and the position of the receiver 103. The position of the transmitter 104 is calculated. Here, as the position of the receiver 103, the positions of the plurality of receivers 103 indicated by the plurality of receiver position information 164 included in the notification signal 153, or a plurality of receptions stored in the receiver position storage unit 134. The position of the vessel 103 is used.

  Note that the received radio wave intensity changes according to the distance between the receiver 103 and the transmitter 104 (the shorter the distance, the higher the received radio wave intensity). Therefore, the lost child information generation unit 135 can determine the position of the transmitter 104 from the received radio wave intensity and the position of the receiver 103 with respect to the plurality of receivers 103.

  The display unit 136 displays the position of the transmitter 104 detected by the lost child information generation unit 135. FIG. 12 is a diagram illustrating a display example of the position of the transmitter 104 (lost child transmitter). As shown in FIG. 12, the display unit 136 displays the position 171 of the lost child transmitter two-dimensionally. Further, the position 172 of the receiver 103 and the position 173 of the management apparatus 102 may be displayed together. Note that these pieces of information may be displayed on the floor plan or the like if they are indoors, and may be displayed on the map information if they are outdoors.

  Although an example in which the position of the lost child transmitter is displayed two-dimensionally is shown here, it may be displayed three-dimensionally.

  Further, the lost child information generation unit 135 transmits the lost child only from information indicating whether or not each receiver 103 has received the detection signal 151 (or information indicating whether the received radio wave intensity is equal to or higher than a predetermined threshold). The position of the vessel may be detected. That is, the lost child information generation unit 135 may not use the received radio wave intensity information 163. For example, the lost child information may be information indicating the receiver 103 that has received the detection signal 151. For example, in the example illustrated in FIG. 12, the receiver 103 that has received the detection signal 151 may be highlighted instead of displaying the position 171 of the lost child transmitter.

  The lost child information generation unit 135 may not use the position information of the receiver 103. For example, when a staff member who carries the receiver 103 (for example, a smartphone) is in a building, position measurement using GPS cannot be performed. In such a case, or when the receiver 103 does not include the position measurement unit 127, the lost child information generation unit 135 indicates whether or not the detection signal 151 has been received by each receiver 103 as lost child information. Only information may be generated, or only information indicating the receiver 103 that has received the detection signal 151 may be generated.

  Moreover, information other than the above may be included in the lost child information. For example, the display unit 136 may display the received radio wave intensity. Further, the lost child information generation unit 135 may generate information indicating the moving direction or moving speed of the lost child transmitter based on the plurality of notification signals 153 received in time series.

  The description will be given again with reference to FIG.

  After transmitting the notification signal 153 in step S110, the receiver 103B receives the detection signal 151 transmitted from the search mode transmitter 104 (S109), and generates the notification signal 153 based on the received detection signal 151. Then, the generated notification signal 153 is transmitted to the management apparatus 102 (S112). The management apparatus 102 updates the lost child information based on the newly received notification signal 153, and displays the updated lost child information (S113).

  Thereafter, these processes are repeatedly executed until the lost child is protected.

  As described above, in the lost child search system 100 according to the present embodiment, the transmitter 104 has the normal mode and the search mode in which the transmission interval of the detection signal 151 is shorter than that in the normal mode. Furthermore, when a lost child occurs, only the lost child transmitter carried by the lost child is set to the search mode. Thereby, the position of the lost child transmitter can be searched with high accuracy. In addition, since the transmission interval of the detection signal 151 of the transmitter 104 other than the stray transmitter is set to be long, congestion of radio signals can be suppressed and power consumption of the transmitter 104 can be reduced.

  Moreover, in the lost child search system 100 according to the present embodiment, only the notification signal 153 for the detection signal 151 transmitted from the lost child transmitter is transmitted to the management device 102 and transmitted from the transmitter 104 other than the lost child transmitter. The notification signal 153 for the detection signal 151 is not transmitted to the management apparatus 102. Thereby, since the number of the notification signals 153 transmitted can be suppressed, congestion of radio signals can be suppressed. This is particularly effective when a plurality of receivers 103 construct a wireless network and relay processing is performed.

  Although an example in which the receiver 103 does not transmit the notification signal 153 related to other than the lost child transmitter to the management apparatus 102 has been described here, the receiver 103 transmits the notification signal 153 related to all the transmitters 104 to the management apparatus 102. However, the management apparatus 102 may manage the positions of all the transmitters 104.

  In the above description, the case where there is one lost child transmitter has been described as an example, but a plurality of lost child transmitters may be set at the same time.

  Hereinafter, an operation flow in each apparatus will be described.

  First, the operation of the management apparatus 102 will be described. FIG. 13 is a flowchart showing an operation flow of the management apparatus 102.

  First, the reception unit 131 waits for the designation of a lost child transmitter, which is the transmitter 104 carried by the lost monitoring subject, among a plurality of monitoring subjects (S201).

  When the reception unit 131 receives the designation of the lost child transmitter (Yes in S201), the lost child specification unit 132 notifies the plurality of receivers 103 of the lost child transmitter. Specifically, the lost child designation unit 132 generates a lost child designation signal 154, and the communication unit 133 transmits the lost child designation signal 154 to the plurality of receivers 103 (S202).

  Next, the management apparatus 102 stands by until a notification signal 153 is received from any of the receivers 103 (S203). When the notification signal 153 is received (Yes in S203), the lost child information generation unit 135 determines which receiver 103 of the plurality of receivers 103 has received the detection signal 151 from the lost child transmitter. The lost child information indicating the position of the lost child transmitter is generated (S204). Specifically, the lost child information generation unit 135 generates lost child information using the position information of the receiver 103 that has received the detection signal 151 from the lost child transmitter (S204).

  Specifically, the lost child information generation unit 135 uses the receiver position information 164 included in the notification signal 153 to specify the position of the receiver 103 that has received the detection signal 151 from the lost child transmitter. Alternatively, the lost child information generation unit 135 uses the receiver ID 162 included in the notification signal 153 to specify the position of the receiver 103 that has received the detection signal 151 from the lost child transmitter. For example, in the receiver position storage unit 134, position information (for example, two-dimensional coordinates or three-dimensional coordinates) of the receiver 103 that is associated with each of the plurality of receiver IDs and identified by the receiver ID. It is remembered. The lost child information generation unit 135 acquires the position information of the receiver 103 that is associated with the receiver ID 162 included in the notification signal 153 from the receiver position storage unit 134. Note that the position information stored in the receiver position storage unit 134 may include the latitude and longitude of the position where the receiver 103 is disposed, or the latitude, longitude, and altitude. Further, the position information may include a name such as a building or a place as the receiver 103 is arranged. Further, the position information may include information indicating the floor in the building where the receiver 103 is arranged. The position information may include a name unique to the receiver 103.

  The lost child information generation unit 135 generates lost child information indicating that a lost child transmitter is present in the vicinity of the identified position of the receiver 103.

  Further, the lost child information generation unit 135 estimates the distance from the position of the receiver 103 to the lost child transmitter by using the received intensity indicated by the received radio wave intensity information 163 included in the notification signal 153, thereby obtaining the lost child transmitter. Is estimated. Specifically, the lost child information generation unit 135 determines that the lost child transmitter exists closer to the receiver 103 as the reception strength is higher.

  When a plurality of notification signals 153 are received from the plurality of receivers 103, the lost child information generation unit 135 uses the information included in the plurality of notification signals 153 and the position information of the plurality of receivers 103. Estimate the position of the lost child transmitter.

  Further, when there are a plurality of lost child transmitters, the lost child information generation unit 135 refers to the transmitter ID 161C included in the notification signal 153, identifies the target lost child transmitter of the notification signal 153, and transmits the lost child information. For each device, the position of the lost child transmitter is estimated.

  The display unit 136 displays the generated lost child information (S205). When there are a plurality of lost child transmitters, the display unit 136 may display the lost child information of the designated lost child transmitters, or simultaneously display the positions of the plurality of lost child transmitters in one screen. May be.

  Next, the management apparatus 102 determines whether or not the lost child search process is completed (S206). For example, when an instruction to end the lost child search process is input by a user operation on the management apparatus 102, the management apparatus 102 determines to end the lost child search process (Yes in S206). For example, an instruction to end the lost child search process and information (for example, transmitter ID) specifying the transmitter 104 to end the lost child search process are input.

  Note that an instruction to end the lost child search process may be input via another device. For example, when a predetermined operation is performed on the receiver 103 or the transmitter 104 (lost child transmitter), an instruction to end the lost child search process may be transmitted to the management device 102. Moreover, the timing at which the determination process (S206) of the end of the lost child search process is performed may be an arbitrary timing.

  When there is no instruction to end the lost child search process (No in S206), the processes after Step S203 are performed again. Accordingly, the lost child information is updated every time the management apparatus 102 receives the notification signal 153.

  Note that the lost child transmitter acceptance processing (S201 and S202), the lost child information generation processing (S203 to S205), and the lost child search operation end processing (S206) may be performed independently (in parallel).

  Next, the operation of the receiver 103 will be described. FIG. 14 is a flowchart showing the operation flow of the receiver 103.

  First, the receiver 103 waits for a notification of a lost child transmitter from the management apparatus 102. Specifically, the receiver 103 waits for the communication unit 121 to receive the lost child designation signal 154 from the management apparatus 102 (S221).

  When the communication unit 121 receives the lost child designation signal 154 from the management apparatus 102 (Yes in S221), the lost child setting control unit 122 registers the transmitter 104 designated by the received lost child designation signal 154 as a lost child transmitter. (S222). Specifically, the lost child setting control unit 122 stores the transmitter ID 161 </ b> B included in the lost child designation signal 154 in the lost child transmitter storage unit 123.

  Next, the receiver 103 waits until receiving the detection signal 151 from the lost child transmitter (S223 and S224). Specifically, when the wireless reception unit 125 receives the detection signal 151, the lost child setting control unit 122 transmits the transmitter ID 161 </ b> A included in the detection signal 151 stored in the lost child transmitter storage unit 123. If it matches, it determines with having received the detection signal 151 from the lost child transmitter.

  When the detection signal 151 from the lost child transmitter is received (Yes in S223 and Yes in S224), the wireless transmission unit 124 switches the mode switching signal 152 for switching the operation mode of the transmitter 104 from the normal mode to the search mode. Is wirelessly transmitted to the lost child transmitter (S225).

  Further, as described above, the mode switching signal 152 is transmitted during an operation period in which the transmitter 104 can receive a radio signal immediately after the transmitter 104 transmits the detection signal 151. The mode switching signal 152 is transmitted when the detection signal 151 from the lost child transmitter is first received after the lost child transmitter is registered. For example, the mode switching signal 152 includes a transmitter ID of a lost child transmitter.

  When a plurality of lost child transmitters are registered, the lost child setting control unit 122 includes a plurality of transmitters whose transmitter ID 161A included in the detection signal 151 is stored in the lost child transmitter storage unit 123. It is confirmed whether or not it matches any of the IDs. If they match, the mode switching signal 152 including the matching transmitter ID is generated.

  When the wireless reception unit 125 receives the detection signal 151 from the lost child transmitter, the notification signal generation unit 128 notifies the management device 102 that the detection signal 151 from the lost child transmitter has been received (S223). Yes and Yes in S224). For example, the notification signal generation unit 128 generates a notification signal 153 indicating that the detection signal 151 from the lost child transmitter has been received, and controls the communication unit 121 so that the generated notification signal 153 is transmitted to the management apparatus 102. Radio transmission is performed for the destination (S226).

  Next, the receiver 103 stands by until receiving the next detection signal 151 from the lost child transmitter (S227 and S228). When the detection signal 151 is received from the lost child transmitter (Yes in S227 and Yes in S228), the communication unit 121 wirelessly transmits the notification signal 153 to the management apparatus 102 (S229).

  Next, the receiver 103 determines whether or not the lost child search process is completed (S230). For example, when an instruction to end the lost child search process is input by a user operation on the receiver 103, the receiver 103 determines to end the lost child search process (Yes in S230). Note that an instruction to end the lost child search process may be input via another device (for example, the management device 102 or the transmitter 104). In addition, the timing at which the end of the lost child search process determination process (S230) is performed may be any timing.

  When the lost child search process is completed (Yes in S230), the lost child setting control unit 122 cancels the registration of the lost child transmitter that has completed the search (S231). Specifically, the lost child setting control unit 122 deletes the transmitter ID of the lost child transmitter that has been searched from the lost child transmitter storage unit 123.

  When there is no instruction to end the lost child search process (No in S230), the processes after Step S227 are performed again. Thereby, the receiver 103 transmits the notification signal 153 to the management apparatus 102 every time it receives the detection signal 151 from the lost child transmitter.

  In this way, the communication unit 121 wirelessly transmits the notification signal 153 when receiving the detection signal 151 from the lost child transmitter among the plurality of transmitters 104, and other than the lost child transmitter among the plurality of transmitters 104. When the detection signal 151 is received from the transmitter 104, a signal indicating that the detection signal 151 has been received from the transmitter 104 is not wirelessly transmitted to the management apparatus 102. Thereby, congestion of radio signals is reduced.

  Note that registration of the lost child transmitter and transmission processing of the mode switching signal 152 (S221 to S225), transmission processing of the notification signal 153 (S227 to S229), and termination processing of the lost child search operation (S230 to S231) are independent ( In parallel).

  Next, the operation of the transmitter 104 will be described. FIG. 15 is a flowchart showing an operation flow of the transmitter 104.

  First, the transmission interval control unit 113 sets the operation mode of the transmitter 104 to the normal mode as an initial state (S241).

  In the normal mode, the wireless transmission unit 111 wirelessly transmits the detection signal 151 at the first interval (long interval) (S242). Further, this operation is repeated until the mode switching signal 152 is received (No in S243).

  When the wireless reception unit 112 receives the mode switching signal 152 (Yes in S243), the transmission interval control unit 113 switches the operation mode of the transmitter 104 from the normal mode to the search mode (S244). For example, the transmission interval control unit 113 switches the operation mode from the normal mode to the search mode when the transmitter ID included in the received mode switching signal 152 matches its own transmitter ID.

  In the search mode, the wireless transmission unit 111 wirelessly transmits the detection signal 151 at a second interval shorter than the first interval (S245). Further, this operation is repeated until the lost child search process is completed (No in S246).

  On the other hand, when an instruction to end the lost child search process is input (Yes in S246), the transmission interval control unit 113 switches the operation mode of the transmitter 104 from the search mode to the normal mode (S241). Thereafter, the processing after step S242 is performed again.

  For example, the end of the lost child search process is instructed by operating a reset switch (for example, manual or magnetic switch) provided in the transmitter 104. Note that the end of the lost child search process may be instructed via another device (for example, the management device 102 or the receiver 103). Moreover, the timing at which the determination process (S246) of the end of the lost child search process is performed may be an arbitrary timing.

  The instruction to end the lost child search process for the management device 102, the receiver 103, and the transmitter 104 may be performed based on an operation on a single device (for example, an operation on the management device 102). You may perform based on operation with respect to an apparatus. For example, an operation to the management apparatus 102 instructs the management apparatus 102 and the plurality of receivers 103 to end the lost child search process, and an operation to the transmitter 104 instructs the transmitter 104 to end the lost child search process. It may be done.

  In addition, as an instruction to end the lost child search process for the transmitter 104, a process similar to the protocol for switching the operation mode of the transmitter 104 described above may be performed. In other words, the receiver 103 receives a signal instructing the end of the lost child search process (the operation mode of the transmitter 104 as the search mode) immediately after receiving the detection signal 151 from the lost child transmitter (period T3 in FIG. 9). To the normal mode) may be wirelessly transmitted to the lost child transmitter. In the search mode, the transmitter 104 may shift to the operating state every time the detection signal 151 is transmitted in the search mode, or once every predetermined number of transmissions. You may move to the operating state.

  Although the lost child search system according to the embodiment of the present invention has been described above, the present invention is not limited to this embodiment.

  For example, the detection signal 151 may include mode information indicating the operation mode of the transmitter 104 when the detection signal 151 is transmitted. In this case, the receiver 103 that has received the detection signal 151 from the lost child transmitter refers to the mode information included in the detection signal 151, and when the operation mode of the lost child transmitter is the normal mode, the lost child transmission is performed. A mode switching signal 152 is transmitted to the device. Thereby, when the lost child transmitter cannot correctly receive the mode switching signal 152, the receiver 103 can transmit the mode switching signal 152 again.

  In addition, each signal described above may include header information including information indicating the type of the signal. Each signal may include a flag for notifying that the transmission source device is waiting to receive a signal. For example, the detection signal 151 includes information indicating whether or not the transmission source transmitter 104 is waiting to receive the mode switching signal 152 (indicating whether or not the transmission device 104 is in an operating state). May be.

  Moreover, although the example which applies this invention to the lost child search system which searches for a lost child was described in the said description, this invention is applicable also to the system which searches the designated person among several people. Further, the present invention can be applied not only to a person but also to a system for searching for a moving body such as an animal or a movable object. That is, the transmitter 104 may be held (carried or mounted) on each of a plurality of moving bodies. Furthermore, the present invention can also be applied to a position detection system for detecting the position of a moving body.

  That is, the position detection system according to the present embodiment is a system for detecting the position of a moving body, which is held by each of the plurality of moving bodies and transmits a detection signal wirelessly, A plurality of receivers for receiving signals. The said position detection system receives designation | designated of the object transmitter which is a transmitter currently hold | maintained at the object mobile body among several mobile bodies. The position detection system changes the operation mode of the transmitter from a first mode in which a detection signal is wirelessly transmitted at a first interval to a second mode in which a detection signal is wirelessly transmitted at a second interval shorter than the first interval. A first mode switching signal for switching is wirelessly transmitted to the target transmitter. When the target transmitter receives the first mode switching signal, the target transmitter switches the operation mode from the first mode to the second mode. The position detection system further generates information indicating the position of the target transmitter based on which of the plurality of receivers has received the detection signal from the target transmitter.

  For example, the position detection system according to the present embodiment can be used in concert venues and event venues in addition to the amusement parks described above. In this case, the transmitter 104 described above is distributed and held to visitors and the like.

  When an administrator or a visitor wants to search for a specific person in the hall, a transmitter carried by a person to be searched from a terminal such as a personal computer, a smartphone, or a tablet terminal as in the above-described lost child search system. 104 is designated. Thereby, the operation mode of the transmitter 104 carried by the search target person is switched to the second mode (search mode). Then, the position of the search target person is displayed on the terminal by the above-described processing.

  In addition to the current position of the search target person, the action trajectory of the search target person may be displayed as the displayed information.

  Further, by using the above system at an event venue or the like, the manager and visitors can grasp which area is crowded and which area is crowded. Furthermore, the manager can prevent many visitors from moving to the venue at once based on such information. Specifically, the administrator can instruct some visitors to wait without moving to the area. In addition, when it is confirmed that the congestion has been alleviated, the manager can sequentially instruct visitors to enter.

  For example, such an instruction to a visitor can be realized when the transmitter 104 or a terminal to which the transmitter 104 is connected or incorporated has a communication function. In addition, the instruction to the visitor may be given by at least one of video and audio. For example, the transmitter 104 may include at least one of a display unit (such as a liquid crystal display), a lighting device (such as an LED), a buzzer, and a vibrator, and may notify the visitor via these.

  In the above case, the transmitter 104 carried by a visitor in a crowded area among a plurality of visitors may be set to the search mode (second mode) described above. Alternatively, among the plurality of visitors, the transmitter 104 carried by at least one of the visitors who have been given the standby instruction and the visitors who have been given the movement instruction is in the search mode (first 2 mode). Alternatively, the transmitter 104 carried by a visitor who is scheduled to be moved next among the visitors who are instructed to wait may be set to the search mode (second mode) described above.

  As a result, the manager can accurately check the situation of the crowded area and can realize a prompt instruction to the visitors.

  Also, when a visitor leaves from a concert venue or the like, the same processing as described above may be performed.

  In addition, when a plurality of transmitters 104 are set to the search mode at the same time, there is a possibility that radio signals are congested by the plurality of transmitters 104. On the other hand, in the position detection system according to the present embodiment, as shown in FIG. 16, the plurality of transmitters 104 wirelessly transmit detection signals 151 at different timings in the search mode.

  Hereinafter, a plurality of methods for realizing this processing will be described.

  First, the first method will be described. In the first method, each transmitter 104 holds delay information indicating different delay times (timing not to be crowded) in advance. Each transmitter 104 transmits the detection signal 151 at a timing delayed by the delay time indicated by the held delay information from the reference timing in the search mode.

  In this case, it is necessary to synchronize a plurality of transmitters 104. For example, a signal indicating a reference timing is transmitted to a plurality of transmitters 104 periodically or at a predetermined timing, and each transmitter 104 determines a reference timing using the signals. .

  In this case, different delay times may be set for all the transmitters 104 included in the position detection system, or the plurality of transmitters 104 are divided into a plurality of groups, and each group is different from each other. A delay time may be set.

  Also, this delay time may be fixedly set to a value unique to the transmitter 104 or may be switched by operating a switch or the like provided in the transmitter 104. Further, information indicating this delay time may be wirelessly transmitted from the management apparatus 102 when an event occurs.

  Next, the second method will be described. The second method is a method of wirelessly transmitting the delay time from the management apparatus 102 to the transmitter 104. FIG. 17 is a diagram showing the flow of this processing.

  Here, for simplification of description, operations of one management apparatus 102, one receiver 103, and three transmitters 104A, 104B, and 104C will be described.

  First, the plurality of transmitters 104A to 104C are set to the search mode (S301). Each of the transmitters 104A to 104C transmits the detection signal 151 at a predetermined interval. The receiver 103 that has received these detection signals 151 transmits a notification signal 153 to the management apparatus 102 (S302). Here, the notification signal 153 includes reception time information indicating the reception time when the receiver 103 receives the detection signal 151 in addition to the transmitter ID 161A for identifying the transmitter 104 of the transmission source of the detection signal 151. Including. The plurality of receivers 103 are synchronized, and reception times based on a common reference are detected.

  The management apparatus 102 determines the delay times of the plurality of transmitters 104A to 104C using the reception times indicated by the reception time information included in the plurality of notification signals 153 (detection signals 151) (S303). Specifically, as shown in FIG. 16, the management apparatus 102 delays the plurality of transmitters 104A to 104C so that the transmission timings of the detection signals 151 transmitted from the plurality of transmitters 104A to 104C are different from each other. Determine the time. More specifically, when the reception times of the two detection signals 151 are the same or close to each other, the management apparatus 102 delays so that the transmission time of the transmitter 104 that is the transmission source of one detection signal 151 is delayed. Set the time.

  Next, the management apparatus 102 wirelessly transmits delay information indicating the determined delay time of each transmitter to the transmitters 104A to 104C via the receiver 103 (S304). Each of the transmitters 104A to 104C sets the delay time indicated by the received delay information in its own device (S305).

  The delay time need not be set for all the transmitters 104A to 104C, and may be set for one or more transmitters as necessary.

  Thereafter, the transmitters 104A to 104C transmit the detection signal 151 at a timing based on the set delay time (S306).

  With the above processing, the transmission timings of the detection signals 151 transmitted from the plurality of transmitters 104 can be varied as shown in FIG. In addition, the second method does not need to perform a process of synchronizing a plurality of transmitters 104 when compared with the first method, so that power consumption during operation can be reduced and congestion of radio signals can be reduced. it can.

  In addition, here, an example in which the delay information indicating the delay time is transmitted to the transmitter 104 has been described. However, transmission time setting information indicating the transmission time of the detection signal 151 is transmitted to the transmitter 104, and the transmitter 104 The transmission timing may be adjusted based on the transmission time setting information. In this case, the detection signal 151 includes transmission time information indicating a transmission time when the detection signal 151 is transmitted from the transmitter 104. The transmission time information is included in the notification signal 153 and transmitted to the management apparatus 102. The management apparatus 102 generates transmission time setting information using the reception time information and transmission time information.

  That is, the position detection system wirelessly transmits timing information (delay information indicating delay time or transmission time information indicating transmission time) indicating different transmission timings to the plurality of transmitters 104. The plurality of transmitters 104 wirelessly transmit the detection signals at different timings based on the transmission timing indicated by the received timing information.

  In addition, the position detection system determines a plurality of transmission timings using reception times at which the receiver 103 receives the plurality of detection signals 151 transmitted from the plurality of transmitters 104.

  Next, the third method will be described. In the third method, each transmitter 104 holds a different random number in advance. In the search mode, each transmitter 104 determines a transmission timing using a stored random number, and transmits a detection signal 151 at the determined transmission timing.

  Next, the fourth method will be described. In the fourth method, each transmitter transmits the detection signal 151 when receiving the detection signal 151 transmitted from another transmitter. Thereby, the timing which the signal 151 for a detection is transmitted from each transmitter can be shifted.

  For example, the transmission order of the detection signal 151 is set in advance to the plurality of transmitters 104. Specifically, the management apparatus 102 wirelessly transmits information indicating the transmission order to each transmitter 104. For example, this information indicates the transmitter ID of the immediately preceding transmitter 104 in the transmission order. This information may be information indicating the transmission order of all or part of the transmitters 104 included in the position detection system. Further, this transmission order may be set in advance for each transmitter 104.

  Each transmitter 104 transmits the detection signal 151 when receiving the detection signal 151 transmitted from the immediately preceding transmitter 104 in the transmission order.

  In addition, each transmitter 104 transmits a detection signal 151 when the detection signal 151 transmitted from the immediately preceding transmitter 104 cannot be received in the transmission order even after a predetermined time has elapsed. Thereby, it is possible to prevent the transmission of the detection signal 151 from being interrupted when each transmitter 104 cannot receive the detection signal 151 from the immediately preceding transmitter 104.

  For example, when the transmitter 104 cannot receive the detection signal 151 transmitted from the immediately preceding transmitter 104 in the order of transmission even after a predetermined time has elapsed since the transmission of the previous detection signal 151. The detection signal 151 is transmitted. Further, when the transmitter 104 holds the information of the transmitter 104 that is two before in the transmission order, the transmitter 104 receives the detection signal 151 transmitted from the transmitter 104 that is two before in the transmission order. Thus, the detection signal 151 may be transmitted when the detection signal 151 transmitted from the immediately preceding transmitter 104 cannot be received in the transmission order even after a predetermined time has elapsed.

  In this way, when there is a transmitter 104 that cannot receive the detection signal 151 transmitted from the immediately preceding transmitter 104 in the transmission order, the management apparatus 102 changes the transmission order, and each transmitter 104 In addition, the changed transmission order may be notified.

  Further, the transmitter 104 that has transmitted the detection signal 151 may shift to a sleep mode that consumes less power than the normal mode until the next transmission. Thereby, the lifetime of a battery can be extended. Further, the transmission order may be changed every predetermined number of times or every time. Thereby, the lifetime of the battery of the some transmitter 104 can be averaged.

  Further, when receiving the detection signal 151, the management apparatus 102 may return an ACK or the like to the transmitter 104 of the transmission source. In this case, each transmitter 104 transmits the detection signal 151 again when ACK cannot be received. Note that the receiver 103 may return ACK or the like to the transmitter 104 of the transmission source. Further, such ACK processing is not limited to the cases of the first to fourth methods, and may be applied to any of the communication protocols described in the present embodiment.

  As shown in FIG. 16, the transmission timing of the detection signal 151 can be shifted by any of the first to fourth methods described above. Thereby, for example, in a concert hall or an event hall, congestion (interference) of radio signals when a plurality of transmitters 104 are simultaneously set to the search mode can be suppressed.

  In the above description, the processing for shifting the transmission timing is performed in the search mode, but the same processing may be performed in the normal mode.

  In addition, the transmission timings of the plurality of transmitters 104 may be shifted after the transmission timings are set for the plurality of transmitters 104 by any of the first to fourth methods described above. In such a case, for example, the deviation may be corrected by a method similar to the second method.

  That is, the notification signal 153 includes reception time information indicating a reception time when the receiver 103 receives the detection signal 151. In addition, the plurality of receivers 103 are synchronized, and reception times based on a common reference are detected.

  The management device 102 stores ideal transmission timings of the plurality of transmitters 104. Alternatively, the management apparatus 102 stores ideal transmission intervals (reception intervals) of the detection signals 151 transmitted from the plurality of transmitters 104, and calculates ideal transmission timing using the transmission intervals. To do.

  The management apparatus 102 determines whether the reception time indicated by the reception time information included in the plurality of notification signals 153 is within an allowable range based on the ideal transmission timing.

  When the reception time is outside the allowable range, the management apparatus 102 instructs the transmitter 104 to correct the transmission timing. Specifically, the management apparatus 102 wirelessly transmits correction information indicating a transmission instruction correction instruction (for example, delay time) of the transmitter 104 to the transmitter 104 via the receiver 103. The transmitter 104 corrects the transmission timing in accordance with the correction instruction indicated by the received correction information.

  Note that these determination processing and correction instructions may be performed by the receiver 103, not by the management apparatus 102. In this case, the ideal transmission timing and transmission interval may be stored in the receiver 103 in advance, or may be transmitted from the management apparatus 102 to the receiver 103. The transmitter 104 stores the ideal transmission timing and transmission interval, and may be transmitted from the transmitter 104 to the receiver 103 or the management apparatus 102.

  Further, the detection signal 151 further includes transmission time information indicating the transmission time at which the detection signal 151 is transmitted from the transmitter 104, and the receiver 103 compares the transmission time with the reception time. It may be determined whether the reception time is within an allowable range. The transmission time information is included in the notification signal 153 and transmitted to the management apparatus 102. The management apparatus 102 may perform the same determination using the reception time and the transmission time.

  In the above description, the example in which the transmitter 104 switches the operation mode when receiving the mode switching signal 152 has been described. However, the transmitter 104 may switch the operation mode at a designated time. The operation in this case will be described below.

  FIG. 18 is a diagram showing the operation in this case. Here, for simplification of description, operations of one management apparatus 102, two receivers 103A and 103B, and one transmitter 104 will be described.

  First, the transmitter 104 operates in the normal mode (S401), and transmits the detection signal 151 at a predetermined cycle (S402). When receiving the detection signal 151, the receiver 103B transmits a notification signal 153 to the management apparatus 102 (S403).

  Based on the received notification signal 153, the management apparatus 102 displays position information indicating the position of the transmitter 104 (S404). In addition, when the some transmitter 104 exists, the information which shows each position of the some transmitter 104 is displayed.

  Next, the user of the management apparatus 102 performs an operation of selecting the transmitter 104 for switching the operation mode and an operation for designating a switching time for switching the operation mode. For example, the user selects the transmitter 104 that switches the operation mode by selecting one or more transmitters 104 displayed on the two-dimensional map. The user may select the transmitter 104 that switches the operation mode by selecting one or more transmitters 104 displayed in the list.

  Thereby, the management apparatus 102 receives the transmitter 104 which switches an operation mode, and the switching time which switches an operation mode (S405). Next, the management apparatus 102 transmits a designation signal indicating the transmitter 104 for switching the operation mode and the switching time for switching the operation mode to the plurality of receivers 103A and 103B (S406).

  FIG. 19 is a diagram illustrating the configuration of the designation signal. As shown in FIG. 19, the designation signal includes a transmitter ID 161B of a transmitter whose operation mode is to be switched, and switching time information 165 for designating a switching time for switching the operation mode. The switching time information 165 may be information indicating an absolute time, or may be information indicating a waiting time from when the switching time information 165 is received until the operation mode is switched. Further, the switching time information 165 may indicate only the time when the operation mode is switched from the normal mode to the search mode, or may indicate the time range when the operation mode is switched to the search mode. In other words, the switching time information 165 may indicate a time when the operation mode is switched from the normal mode to the search mode and a time when the operation mode is returned to the normal mode after the operation mode is switched to the search mode. The switching time information 165 may indicate only the time at which the operation mode is switched from the search mode to the normal mode.

  Receiving the designation signal, the receivers 103A and 103B register the transmitter and switching time designated by the designation signal (S407). When the detection signal 151 transmitted from the registered transmitter is received in any of the plurality of receivers 103 in a state where the transmitter is registered, the receiver 103B receives the mode switching signal (S408). 152 is transmitted to the transmitter 104 (S409). The details of the series of processes are the same as those shown in FIG.

  In this case, a mode switching signal 152 including switching time information 165 is transmitted to the transmitter 104. Further, the method for transmitting the switching time information 165 to the transmitter 104 is not limited to this method, and other methods described above may be used.

  In addition to the switching time information 165, the designation signal and mode switching signal 152 may include the timing information (delay information or transmission time information) described above. Note that the timing at which the timing information is transmitted does not have to be the same as that of the mode switching signal 152. For example, the timing information may be transmitted to the transmitter 104 before the mode switching signal 152 is transmitted.

  The transmitter that has received the mode switching signal 152 waits until the switching time indicated by the switching time information 165 (S410), and switches the operation mode from the normal mode to the search mode at the switching time (S411). The transmitter 104 may operate in the normal mode instead of waiting in step S410.

  In the search mode, the transmitter 104 transmits the detection signal 151 at short intervals (S412). The receiver 103B that has received the detection signal 151 transmits a notification signal 153 to the management apparatus 102 (S413). The management apparatus 102 updates the location information based on the newly received notification signal 153, and displays the updated location information (S414).

  As described above, the transmitter 104 can be switched to the search mode at the time registered in advance. For example, when restricting entrance to a plurality of visitors at a concert venue and an event venue, the transmitter 104 carried by a target visitor to be instructed to enter can be sequentially switched to the search mode.

  In addition, the timing which sets switching time is not limited to the said timing, Arbitrary timing may be sufficient. For example, the switching time may be set before distributing the transmitter 104 to visitors. In this case, the method for setting the switching time may be other than the method using the wireless communication described above. For example, the switching time may be set by operating a button or a switch provided in the transmitter 104.

  In the above description, the switching time information 165 is transmitted to the transmitter 104 in advance. However, the receiver 103 transmits the mode switching signal 152 to the transmitter 104 at the timing when the switching time is reached. Also good. In this case, the mode switching signal 152 may not include the switching time information 165.

  In the above description, the switching time information 165 is transmitted when the receiver 103 receives the detection signal 151, but the receiver 103 receives the switching time when receiving another signal from the transmitter 104. Information 165 may be transmitted to transmitter 104.

  In the above description, the case where two modes (normal mode and search mode) having different transmission intervals of the detection signal 151 are switched has been described as an example. However, the present invention is also applied to switching between three or more modes. Can be applied. Further, the three or more modes may include a sleep mode (third mode) in which the detection signal 151 is not transmitted. For example, in a concert venue or the like, the transmitter 104 possessed by the visitor currently guiding is set to the search mode, and the transmitter 104 possessed by the waiting attendant is set to the normal mode. Further, the transmitter 104 possessed by the visitor after the guidance is performed is set to the sleep mode. Moreover, when leaving the concert, all the transmitters 104 are set to the normal mode or the search mode again.

  That is, the position detection system further switches the operation mode of the transmitter 104 from the first mode (normal mode) or the second mode (search mode) to the third mode (sleep mode) in which the detection signal 151 is not transmitted. A mode switching signal 152 (second mode switching signal) for wireless transmission is transmitted to the target transmitter. When receiving the second mode switching signal, the target transmitter switches the operation mode from the first mode or the second mode to the third mode. This processing can further eliminate congestion of radio signals.

  Note that when switching to the third mode, the switching time may be set in the same manner as described above. Also in this case, the switching time information 165 for designating the switching time may be information indicating an absolute time, and the waiting time from when the switching time information 165 is received to when the operation mode is switched is set. It may be the information shown.

  In addition, the first mode, the second mode, and the third mode may be switched by operating a button or the like received by the transmitter 104. For example, the operation mode may be switched to the first or second mode by operating a button or the like in the third mode.

  As described above, the position detection system according to the present embodiment is a system for detecting the position of a moving body, which is held by each of the plurality of moving bodies, and a transmitter 104 that wirelessly transmits a detection signal. And a plurality of receivers 103 that receive the detection signal 151.

  The position detection system changes the operation mode of the target transmitter, which is one of the plurality of transmitters 104, from the first mode in which the detection signal 151 is wirelessly transmitted at the first interval, and the detection signal 151 from the first interval. Switching time information 165 (first switching time information) for designating a first switching time for switching to the second mode for wireless transmission at a short second interval is acquired.

  For example, the position detection system transmits the acquired switching time information 165 to the target transmitter, and the target transmitter receives the mode switching signal 152 and then changes the operation mode from the first mode to the first mode at the first switching time. Switch to 2 mode. Alternatively, the position detection system transmits the acquired switching time information 165 to the receiver 103, and the receiver 103 wirelessly transmits the mode switching signal 152 to the target transmitter at the first switching time. Alternatively, the target transmitter obtains preset switching time information 165.

  The target transmitter switches the operation mode from the first mode to the second mode at the first switching time. The position detection system further generates information indicating the position of the target transmitter based on which of the plurality of receivers 103 has received the detection signal 151 from the target transmitter.

  The position detection system further includes a second switching for specifying a second switching time for switching the operation mode of the target transmitter from the first mode or the second mode to the third mode in which the detection signal 151 is not transmitted. Get time information. The target transmitter switches the operation mode from the first mode or the second mode to the third mode at the second switching time. This processing can further eliminate congestion of radio signals.

  Each processing unit included in each device included in the lost child search system or the position detection system according to the above-described embodiment is typically realized as an LSI that is an integrated circuit. These may be individually made into one chip, or may be made into one chip so as to include a part or all of them.

  Further, the circuit integration is not limited to LSI, and may be realized by a dedicated circuit or a general-purpose processor. An FPGA (Field Programmable Gate Array) that can be programmed after manufacturing the LSI or a reconfigurable processor that can reconfigure the connection and setting of circuit cells inside the LSI may be used.

  Moreover, you may implement | achieve part or all of the function of each apparatus contained in the lost child search system or position detection system which concerns on the said embodiment, when processors, such as CPU, run a program.

  Furthermore, the present invention may be the above program or a non-transitory computer-readable recording medium on which the above program is recorded. Needless to say, the program can be distributed via a transmission medium such as the Internet.

  In addition, the present invention can be realized not only as a lost child search system or a position detection system, but also as a transmitter, a receiver, or a management device included in the lost child search system or the position detection system. In addition, the present invention can be realized as a lost child search method or a position detection method that uses characteristic means included in such a lost child search system or position detection system as a step, or such a characteristic step is executed by a computer. It can also be realized as a program to be executed.

  Moreover, all the numbers used above are illustrated for specifically explaining the present invention, and the present invention is not limited to the illustrated numbers.

  In addition, division of functional blocks in the block diagram is an example, and a plurality of functional blocks can be realized as one functional block, a single functional block can be divided into a plurality of functions, or some functions can be transferred to other functional blocks. May be. In addition, functions of a plurality of functional blocks having similar functions may be processed in parallel or time-division by a single hardware or software.

  In addition, the order in which the steps shown in the flowchart are executed is for the purpose of illustrating the present invention specifically, and may be in an order other than the above. Also, some of the above steps may be executed simultaneously (in parallel) with other steps.

  As described above, the lost child search system and the position detection system according to one or a plurality of aspects have been described based on the embodiment, but the present invention is not limited to this embodiment. Unless it deviates from the gist of the present invention, various modifications conceived by those skilled in the art have been made in this embodiment, and forms constructed by combining components in different embodiments are also within the scope of one or more aspects. May be included.

  The present invention can be applied to a lost child search system or a position detection system used in an amusement park or the like.

DESCRIPTION OF SYMBOLS 100 Lost child search system 102 Management apparatus 103, 103A, 103B, 103C, 103D, 103E Receiver 104, 104A, 104B, 104C Transmitter 111, 124 Wireless transmission part 112, 125 Wireless reception part 113 Transmission interval control part 114 Power supply part 121 133 Communication Unit 122 Lost Child Setting Control Unit 123 Lost Child Transmitter Storage Unit 126 Reception Strength Measurement Unit 127 Position Measurement Unit 128 Notification Signal Generation Unit 129 Relay Unit 131 Reception Unit 132 Lost Child Designation Unit 134 Receiver Position Storage Unit 135 Lost Child Information Generation Unit 136 Display unit 151 Detection signal 152 Mode switching signal 153 Notification signal 154 Lost child designation signal 161A, 161B, 161C Transmitter ID
162 Receiver ID
163 Received signal strength information 164 Receiver position information 165 Switching time information

Claims (14)

A position detection system for detecting the position of a moving object,
A transmitter that is held in each of a plurality of mobile units and wirelessly transmits a detection signal;
A plurality of receivers for receiving the detection signal,
The position detection system includes:
Accepting designation of a target transmitter that is the transmitter held by the target mobile body among the plurality of mobile bodies,
To switch the operation mode of the transmitter from the first mode in which the detection signal is wirelessly transmitted at a first interval to the second mode in which the detection signal is wirelessly transmitted at a second interval shorter than the first interval. Wirelessly transmitting the first mode switching signal to the target transmitter,
When the target transmitter receives the first mode switching signal, the target transmitter switches the operation mode from the first mode to the second mode,
The position detection system further includes:
A position detection system that generates information indicating a position of the target transmitter based on which of the plurality of receivers has received the detection signal from the target transmitter. When the receiver receives the detection signal from the target transmitter, the receiver wirelessly transmits the first mode switching signal to the target transmitter,
The transmitter is
An operating state in which radio signals can be received and a standby state in which radio signals cannot be received;
The position detection system according to claim 1, wherein the operation state is set during a predetermined period after the detection signal is transmitted in the first mode, and the first mode switching signal is received during the period. The position detection system includes a management device that generates the information indicating the position of the target transmitter,
The receiver is
When the detection signal from the target transmitter is received among the plurality of transmitters, a notification signal indicating that the detection signal from the target transmitter has been received is wirelessly transmitted to the management device. ,
When the detection signal is received from a transmitter other than the target transmitter among the plurality of transmitters, a signal indicating that the detection signal has been received from the transmitter is not wirelessly transmitted to the management device. The position detection system according to claim 1 or 2. The position detection system includes:
Accepts designation of a plurality of said target transmitters,
Wirelessly transmitting the first mode switching signal to the plurality of target transmitters;
The plurality of target transmitters switch the operation mode from the first mode to the second mode when receiving the first mode switching signal,
The position detection system according to claim 1, wherein the plurality of target transmitters wirelessly transmit the detection signals at different timings in the second mode. The position detection system includes:
Wirelessly transmitting timing information indicating different transmission timings to the plurality of target transmitters,
The position detection system according to claim 4, wherein the plurality of target transmitters wirelessly transmit the detection signals at different timings based on the transmission timing indicated by the received timing information. The position detection system includes:
The position detection system according to claim 5, wherein a plurality of the transmission timings are determined using reception times at which the receiver has received the plurality of detection signals transmitted from the plurality of target transmitters. The position detection system according to claim 4, wherein each of the plurality of target transmitters transmits the detection signal when receiving the detection signal transmitted from another target transmitter. The position detection system transmits, to the target transmitter, switching time information for designating a switching time for switching the operation mode from the first mode to the second mode,
The target transmitter switches the operation mode from the first mode to the second mode at the switching time after receiving the first mode switching signal. Position detection system. The position detection system transmits, to the receiver, switching time information for designating a switching time for switching the operation mode from the first mode to the second mode,
The position detection system according to any one of claims 1 to 7, wherein the receiver wirelessly transmits the first mode switching signal to the target transmitter at the switching time. The position detection system further includes:
Wirelessly transmitting a second mode switching signal for switching the operation mode of the transmitter from the first mode or the second mode to a third mode that does not transmit the detection signal to the target transmitter;
The target transmitter, when receiving the second mode switching signal, switches the operation mode from the first mode or the second mode to the third mode. The described position detection system. A position detection system for detecting the position of a moving object,
A transmitter that is held in each of a plurality of mobile units and wirelessly transmits a detection signal;
A plurality of receivers for receiving the detection signal,
The position detection system is configured to transmit the detection signal from the first mode in which an operation mode of a target transmitter that is one of the plurality of transmitters is wirelessly transmitted at a first interval. Obtaining first switching time information for designating a first switching time for switching to a second mode for wireless transmission at a second interval shorter than the interval;
The target transmitter switches the operation mode from the first mode to the second mode at the first switching time,
The position detection system further includes:
A position detection system that generates information indicating a position of the target transmitter based on which of the plurality of receivers has received the detection signal from the target transmitter. The position detection system further includes:
Obtaining second switching time information for specifying a second switching time for switching the operation mode of the target transmitter from the first mode or the second mode to a third mode in which the detection signal is not transmitted;
The position detection system according to claim 11, wherein the target transmitter switches the operation mode from the first mode or the second mode to the third mode at the second switching time. A position detection method in a position detection system that includes a transmitter that is held in each of a plurality of mobile bodies and wirelessly transmits a detection signal, and a plurality of receivers that receive the detection signal,
An accepting step of accepting designation of a target transmitter that is the transmitter held by the target mobile body among the plurality of mobile bodies;
To switch the operation mode of the transmitter from the first mode in which the detection signal is wirelessly transmitted at a first interval to the second mode in which the detection signal is wirelessly transmitted at a second interval shorter than the first interval. A wireless transmission step of wirelessly transmitting the first mode switching signal to the target transmitter;
A transmission interval control step of switching the operation mode of the target transmitter from the normal mode to the second mode when the target transmitter receives the first mode switching signal;
An information generation step of generating information indicating a position of the target transmitter based on which of the plurality of receivers has received the detection signal from the target transmitter. Method. A position detection method in a position detection system that includes a transmitter that is held in each of a plurality of mobile bodies and wirelessly transmits a detection signal, and a plurality of receivers that receive the detection signal,
The operation mode of the target transmitter, which is one of the plurality of transmitters, from the first mode in which the detection signal is wirelessly transmitted at a first interval, and the detection signal is transmitted at a second interval shorter than the first interval An acquisition step of acquiring first switching time information for designating a first switching time for switching to the second mode for wireless transmission in
A transmission interval control step in which the target transmitter switches the operation mode from the first mode to the second mode at the first switching time;
An information generation step of generating information indicating a position of the target transmitter based on which of the plurality of receivers has received the detection signal from the target transmitter. Method.

Images