Distance measurement method and distance measurement system

Abstract

Provided are a distance measurement method and a distance measurement system which, when the distances between a plurality of communication stations are measured, can shorten the processing time required for distance measurement.　The distance measurement method is for the distance measurement system that includes: a first communication station; and a plurality of second communication stations that transmit signals of a plurality of frequencies to-and-from the first communication station to measure the distance to the first communication station. When the plurality of second communication stations receive a request signal from the first communication station, the second communication stations transmit distance measurement data representing the measured distance to the first communication station.

Description

[Technical Field]

[0001] The present disclosure relates to a ranging method and a ranging system. [Background technology]

[0002] Conventionally, there has been a control device that receives information on the radio wave conditions and distribution of multiple communication stations from a measuring mobile body that flies above multiple communication stations and receives radio waves output from the mobile base station, and that has a control unit that determines the position of the mobile base station based on the radio wave conditions and distribution of the multiple communication stations, and a transmission unit that notifies the mobile base station of information on the determined position (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2019-33409 Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, Patent Document 1 does not disclose any measures to shorten the processing time required for determining a position (distance measurement) when determining a moving position based on the radio wave conditions and the distribution of a plurality of communication stations.

[0005] Therefore, an object of the present invention is to provide a ranging method and a ranging system that can reduce the processing time required for ranging when measuring distances between a plurality of communication stations. [Means for solving the problem]

[0006] A ranging method of an embodiment of the present disclosure is a ranging method in a ranging system including a first communication station and a plurality of second communication stations that measure the distance to the first communication station by transmitting signals of multiple frequencies bidirectionally between the first communication station and the second communication station, and when the second communication stations receive a request signal from the first communication station, they transmit ranging data representing the measured distance to the first communication station. [Effects of the Invention]

[0007] It is possible to provide a ranging method and a ranging system that can reduce the processing time required for ranging when measuring distances between a plurality of communication stations. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 illustrates an example of the configuration of a distance measuring system according to an embodiment. [Figure 2] FIG. 1 is a diagram illustrating an example of an operation of the positioning system according to the embodiment. [Figure 3] FIG. 10 illustrates operations performed by a comparative positioning system. [Figure 4] FIG. 10 is a diagram illustrating an example of an operation of a positioning system according to a modified example of the embodiment. [Figure 5] FIG. 10 is a diagram illustrating the operation of a comparative positioning system. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment to which the distance measuring method and distance measuring system of the present disclosure are applied will be described.

[0010] <Embodiment> 1 is a diagram illustrating an example of the configuration of a distance measuring system 300 according to an embodiment. The distance measuring system 300 includes a distance measuring device 100 and a plurality of smartphones 200.

[0011] Each smartphone 200 includes a distance measuring device 200 A. The distance measuring device 100 cooperates with the distance measuring device 200 A of the smartphone 200 to perform distance measurement processing for measuring the distance between the distance measuring device 100 and the smartphone 200 .

[0012] The ranging device 100 is an example of a first communication station, and the multiple ranging devices 200A included in the multiple smartphones 200 are an example of multiple second communication stations. Here, as an example, a configuration will be described in which the ranging device 100 is a fixed station that does not move, and the ranging device 200A included in each smartphone 200 is a mobile station that can move. The fixed station is provided, for example, in a parked vehicle, a building, etc.

[0013] <Configuration of distance measuring device 100> The ranging device 100 includes three antennas 110, a communication unit 120, and an MCU (Micro Controller Unit) 130. The antenna 110 is connected to the communication unit 120 and receives a signal transmitted from the smartphone 200. Although FIG. 1 illustrates a configuration in which the ranging device 100 includes three antennas 110, the ranging device 100 may include four or more antennas 110. Two of the three antennas 110 are arranged on a first axis of two axes that are orthogonal to each other, two are arranged on a second axis of the two axes that are orthogonal to each other, and one of the antennas is arranged on both the first axis and the second axis.

[0014] The communication unit 120 includes an AFE (Analog Front End), an AD (Analog to Digital) converter, etc., and performs signal processing such as AD conversion on the signal received by the antenna 110 from the smartphone 200 and outputs the signal to the MCU 130.

[0015] The MCU 130 has a main control unit 131, a transmission / reception processing unit 132, a distance measurement unit 133, and a memory 134. The MCU 130 is realized by, for example, a microcomputer including a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), an internal bus, etc. The main control unit 131, the transmission / reception processing unit 132, and the distance measurement unit 133 are functional blocks representing the functions of a program executed by the MCU 130. The memory 134 is a functional representation of the memory of the MCU 130.

[0016] The main control unit 131 is a processing unit that controls the entire MCU 130, and performs processes other than those performed by the transmission / reception processing unit 132 and the ranging unit 133. The main control unit 131 performs the following processes: transmitting data representing the phase difference when a signal transmitted from the ranging device 200A is received by the three antennas 110 to the ranging device 200A; transmitting data representing the phase measured by the ranging unit 133 to the ranging device 200A; transmitting a request signal, which will be described later, to the ranging device 200A; and storing the ranging data received from the ranging device 200A in the memory 134. The ranging data is data representing the distance measured by the ranging unit 233 of the ranging device 200A.

[0017] The transmission / reception processing unit 132 transmits and receives signals to and from the distance measuring device 200A of the smartphone 200 in order to acquire data such as phase and frequency components required for the distance measuring unit 133 to perform distance measurement.

[0018] The distance measurement unit 133 performs distance measurement in a time of arrival (ToA) format using one of the three antennas 110. The distance measurement unit 133 measures the phase of a signal received from the distance measurement device 200A of the smartphone 200. Data indicating the measured phase is transmitted by the main control unit 131 to the distance measurement device 200A of the smartphone 200 via the transmission / reception processing unit 132.

[0019] The memory 134 stores programs, data, etc. required for the main control unit 131 and the transmission / reception processing unit 132 to execute processing for transmitting and receiving signals. The memory 134 also stores programs, data, etc. required for the distance measurement unit 133 to execute distance measurement processing, and stores data indicating the phase measured by the distance measurement unit 133. The memory 134 also stores distance measurement data received from the distance measurement device 200A.

[0020] <Configuration of distance measuring device 200A> The distance measuring device 200A includes an antenna 210, a communication unit 220, and an MCU 230. Each antenna 210 is connected to the communication unit 220 and receives a signal transmitted from the smartphone 200.

[0021] The ranging device 200A has, for example, a similar configuration to the ranging device 100, but differs from the ranging device 100 in that the ranging device 200A calculates the distance on its own. The antenna 210, the communication unit 220, and the MCU 230 are similar to the antenna 110, the communication unit 120, and the MCU 130 of the ranging device 100, respectively.

[0022] The MCU 130 has a main control unit 231, a transmission / reception processing unit 232, a distance measurement unit 233, an angle measurement unit 234, and a memory 235. The main control unit 231, the transmission / reception processing unit 232, the distance measurement unit 233, and the memory 235 are similar to the main control unit 131, the transmission / reception processing unit 132, the distance measurement unit 133, and the memory 134 of the MCU 130 of the distance measuring device 100, respectively, but differs from the distance measurement unit 133 in that the distance measurement unit 233 calculates a distance. The MCU 230 also differs from the MCU 130 in that it has an angle measurement unit 234.

[0023] The main control unit 231, the transmission / reception processing unit 232, the distance measurement unit 233, and the angle measurement unit 234 are functional blocks showing the functions of the program executed by the MCU 230. The memory 235 is a functional representation of the memory of the MCU 230.

[0024] The main control unit 231 is a processing unit that controls the entire MCU 230, and performs processes other than those performed by the transmission / reception processing unit 232, the distance measurement unit 233, and the angle measurement unit 234. When the main control unit 231 receives a request signal, which will be described later, from the distance measuring device 100, it transmits distance measurement data to the distance measuring device 100.

[0025] The transmission / reception processing unit 232 transmits and receives signals to and from the ranging device 100 in order to obtain data such as phase and frequency components, and phase difference data, which are necessary for the ranging unit 233 and the angle measuring unit 234 to perform ranging and angle measurement.

[0026] The ranging unit 233 performs ranging processing in cooperation with the ranging unit 133, transmits signals of multiple frequencies from the antenna 210 to the ranging device 100, and receives signals of multiple frequencies from the ranging device 100. The ranging unit 233 acquires data from the ranging device 100 indicating the phase of each frequency when the ranging device 100 receives the ranging signal.

[0027] The distance measuring unit 233 calculates the total phase (round-trip phase) for each frequency between the phase when the antenna 210 receives the signal of each frequency and the phase when the distance measuring device 100 receives the signal of each frequency, and measures the distance between the distance measuring device 100 and the smartphone 200 (distance measuring device 200A) from the relationship between the multiple frequencies and the round-trip phase at each frequency. The distance measuring unit 233 stores distance measurement data indicating the measured distance in the memory 235.

[0028] The angle measuring unit 234 measures the elevation angle and azimuth angle in a polar coordinate system of the position of the ranging device 100 relative to the ranging device 200A in the AoA (Angle of Arrival) format based on the data representing the phase difference transmitted from the ranging device 100. The data representing the phase difference transmitted from the ranging device 100 is data representing the phase difference when a signal transmitted by the ranging device 200A is received by the three antennas 110 of the ranging device 100. The data representing the phase difference transmitted from the ranging device 100 is transmitted from one of the three antennas 110 of the ranging device 100, and is received by the ranging device 200A by the antenna 210. The angle measuring unit 234 stores angle data representing the measured elevation angle and azimuth angle in the memory 235.

[0029] The memory 235 stores programs, data, etc. required for the main control unit 231 and the transmission / reception processing unit 232 to execute processing for transmitting and receiving signals. The memory 235 also stores programs, data, etc. required for the distance measurement unit 233 and the angle measurement unit 234 to execute distance measurement and angle measurement processing, and further stores distance measurement data and angle measurement data.

[0030] <Operation of the ranging system 300> Fig. 2 is a diagram showing an example of the operation of the distance measuring system 300. Fig. 2 shows the operations of the distance measuring device 100 (Anchor) and four distance measuring devices 200A (Tag1 to Tag4) in chronological order. In Fig. 2, the vertical axis is the time axis, and indicates the passage of time from top to bottom.

[0031] At time t1, Anchor (ranging device 100) performs Ranging (R1) with Tag1 (ranging device 200A). Ranging (R1) includes ranging for ranging and ranging for angle measurement. The time required for Ranging is, for example, 15 ms. Ranging (R2) to Ranging (R4) similarly include ranging for ranging and ranging for angle measurement.

[0032] Ranging for ranging is a process in which ranging device 200A transmits a ranging signal to ranging device 100, ranging device 100 transmits a ranging signal of the same frequency to ranging device 200A, and further transmits data representing the phase when ranging device 100 receives the ranging signal from ranging device 200A to ranging device 200A. This process is performed on ranging signals of multiple frequencies.

[0033] In the ranging for angle measurement, an angle measurement signal is transmitted from the antenna 210 to the ranging device 100, which receives the signal using the three antennas 110. The ranging device 100 then transmits data representing the phase difference between the signals received by the three antennas 110 to the ranging device 200A from one of the three antennas 110. The data representing the phase difference includes the phase difference between the signals received by the two antennas 110 arranged on the first axis and the phase difference between the signals received by the two antennas 110 arranged on the second axis. The ranging device 200A then receives the data representing the phase difference from the ranging device 100. In this way, the ranging for angle measurement is a process from transmitting the angle measurement signal from the antenna 210 to the ranging device 100 to receiving the data representing the phase difference by the ranging device 200A.

[0034] When Anchor (ranging device 100) completes Ranging (R1) with Tag1 (ranging device 200A), it performs Ranging (R2) with Tag2 (ranging device 200A) at time t2. Similarly, when Anchor (ranging device 100) completes Ranging (R2) with Tag2, it performs Ranging (R3) with Tag3 (ranging device 200A) at time t3. Furthermore, when Anchor (ranging device 100) completes Ranging (R3) with Tag3, it performs Ranging (R4) with Tag4 (ranging device 200A) at time t4. Ranging (R4) with Tag4 is completed before time t5.

[0035] In this way, the distance measuring device 100 performs a transmission process of bidirectionally transmitting distance measurement signals of multiple frequencies to each of the multiple distance measuring devices 200A in turn. The transmission process is a transmission and reception process in which the distance measuring device 100 transmits distance measurement signals of multiple frequencies in both directions to each of the multiple distance measuring devices 200A in turn, thereby transmitting and receiving data bidirectionally. In the transmission process, the distance measuring device 100 performs Ranging (R1) to (R4) with the multiple distance measuring devices 200A (Tag1 to Tag4). The distance measuring device 100 performs Ranging (R1) to (R4) with each of the multiple distance measuring devices 200A in turn in a time-division manner. Performing in a time-division manner means that the Ranging (R1) to (R4) between the distance measuring device 100 and each distance measuring device 200A do not overlap.

[0036] Furthermore, when Ranging is completed, each ranging device 200A performs ToA and AoA calculation processing. Tag1 performs ToA and AoA calculation processing (1) between times t2 and t4, and Tag2 performs ToA and AoA calculation processing (2) between times t3 and t5. Tag3 performs ToA and AoA calculation processing (3) from time t4 until shortly after time t5, and Tag4 performs ToA and AoA calculation processing (4) from time t5 until shortly before time t6. In FIG. 2, the time during which Tag1 to Tag4 perform ToA and AoA calculation processing is referred to as calculation processing time.

[0037] When Anchor (ranging device 100) completes ranging with Tag1 to Tag4, it transmits a request signal to Tag1 after time t5, and Tag1 transmits ranging data and angle data to the ranging device 100. Furthermore, when Anchor (ranging device 100) receives ranging data and angle data from Tag1, it transmits a request signal to Tag2, and Tag2 transmits ranging data and angle data to the ranging device 100. When Anchor (ranging device 100) receives ranging data and angle data from Tag2, it transmits a request signal to Tag3, and Tag3 transmits ranging data and angle data to the ranging device 100. When Anchor (ranging device 100) receives ranging data and angle data from Tag3, it transmits a request signal to Tag4, and Tag4 transmits ranging data and angle data to the ranging device 100.

[0038] In this way, the distance measuring device 100 transmits a request signal to each of the plurality of distance measuring devices 200A in turn, and the plurality of distance measuring devices 200A transmit distance measurement data and angle data to the distance measuring device 100 in the order in which the request signals were transmitted.

[0039] In other words, the distance measuring device 100 transmits a request signal to any one of the multiple distance measuring devices 200A, receives distance measurement data and angle data from that one distance measuring device 200A, and then transmits a request signal to any other one of the multiple distance measuring devices 200A, and receives distance measurement data and angle data from that other one distance measuring device 200A.

[0040] In other words, the ranging device 100 performs a transmission process to transmit signals of multiple frequencies in both directions in turn with each of the multiple ranging devices 200A, and then transmits a request signal to each of the multiple ranging devices 200A in a time-division manner according to the order in which the transmission process was performed, and receives ranging data and angle data.

[0041] Furthermore, the distance measuring device 100 transmits a request signal after the calculation processing time has elapsed for each of Tag 1 to Tag 4. Therefore, the distance measuring device 100 transmits a request signal for each of Tag 1 to Tag 4 after the calculation processing time required for each of Tag 1 to Tag 4 to calculate the distance has elapsed.

[0042] The distance measuring device 100 completes receiving the distance measurement data and angle data from Tag1 to Tag4 by time t6. The time required for the distance measuring device 100 to receive the distance measurement data and angle data from Tag1 to Tag4 after transmitting the request signal to Tag1 to Tag4 is, for example, 20 ms.

[0043] That is, the time required from when the distance measuring device 100 starts Ranging with Tag1 (distance measuring device 200A) at time t1 until when it receives distance measurement data and angle data from Tag4 at time t6 is 80 ms. This required time is synonymous with the total processing time.

[0044] <Operation of the comparative positioning system 30> Here, the operation of the comparative positioning system 30 will be described with reference to Fig. 3. Fig. 3 is a diagram showing the operation performed by the comparative positioning system 30. In the comparative positioning system 30, Anchor performs calculation processing of distance measurement and angle measurement using ToA and AoA. Note that the comparative positioning system 30 and the operation of the comparative positioning system 30 shown in Fig. 3 are not conventional technology.

[0045] Anchor performs ranging for each of Tag1 to Tag4, then performs calculations of distance and angle measurement using ToA and AoA, and after the calculations of distance and angle measurement using ToA and AoA are completed, performs ranging for the next tag.

[0046] 3, at time t11, Anchor starts Ranging (R1) with Tag1, and when Ranging (R1) with Tag1 is completed, it performs calculation processing (1) of ranging and angle measurement using ToA and AoA using phase data acquired in Ranging (R1) with Tag1, and obtains ranging data and angle measurement data. As an example, the total time required for Ranging (R1) and calculation processing (1) of ranging and angle measurement using ToA and AoA is 35 ms.

[0047] At time t12, Anchor starts Ranging (R2) with Tag2, and when Ranging (R2) with Tag2 is completed, it performs calculation process (2) of distance and angle measurement using ToA and AoA using the phase data acquired in Ranging (R2) with Tag2.

[0048] At time t13, Anchor starts Ranging (R3) with Tag3, and when Ranging (R3) with Tag3 is completed, it performs calculation process (3) of distance and angle measurement using ToA and AoA using the phase data acquired in Ranging (R3) with Tag3.

[0049] At time t14, Anchor starts Ranging (R4) with Tag4, and when Ranging (R4) with Tag4 is completed, Anchor performs calculation process (4) of distance and angle measurement by ToA and AoA using the phase data acquired in Ranging (R4) with Tag4. All processes are completed at time te.

[0050] In this way, if Anchor performs the distance and angle measurement calculation processes (1) to (4) using ToA and AoA, and Ranging (R1) to (R4) and the distance and angle measurement calculation processes (1) to (4) using ToA and AoA are performed in a time-division manner so as not to overlap in the time axis direction, the time required from when Anchor starts Ranging (R1) with Tag1 at time t11 until all processing is completed at time te is 140 ms (35 ms × 4).

[0051] <Comparison of the operations of the ranging system 300 and the comparative positioning system 30> As described above, in the ranging system 300 of the embodiment, the ranging device 100 (Anchor) does not perform the calculation processes (1) to (4) of ranging and angle measurement using ToA and AoA, but the ranging device 200A (Tag1 to Tag4) of the smartphone 200 performs the calculation processes (1) to (4) of ranging and angle measurement using ToA and AoA. The ranging device 100 performs Ranging (R1) to (R4) with Tag1 to Tag4 in order in a time-division manner, and when Ranging (R1) to (R4) is completed, Tag1 to Tag4 immediately perform the calculation processes (1) to (4) of ranging and angle measurement using ToA and AoA. In addition, in order to obtain distance measurement data and angle measurement data, the distance measurement device 100 transmits a request signal when the distance measurement and angle measurement calculation processes (1) to (4) using the ToA and AoA of each of Tag1 to Tag4 are completed, and receives distance measurement data and angle measurement data from each of Tag1 to Tag4.

[0052] By performing such processing, the distance measuring system 300 of the embodiment reduces the required time to 80 ms compared to the required time (140 ms) of the comparative positioning system 30. This means that the required time is reduced by more than 40%.

[0053] In the above, we have described a form in which the ranging device 200A (Tag1 to Tag4) performs calculation processing for ranging and angle measurement using ToA and AoA, but it is also possible for the ranging device 200A (Tag1 to Tag4) to perform calculation processing for ranging using ToA and not to perform calculation processing for angle measurement using AoA.

[0054] To perform ranging by ToA, ranging signals of multiple frequencies are transmitted bidirectionally between the ranging device 100 and each of the ranging devices 200A (Tags 1 to 4) during ranging ranging, and data indicating the phase at which the ranging device 100 received the ranging signal is transmitted to the ranging device 200A, which requires a long time. In contrast, to perform angle measurement by AoA, ranging signals of a single frequency are received once by the three antennas 110 during angle measurement ranging, and the ranging device 100 transmits data indicating the phase difference to the ranging device 200A, which then performs calculation processing for angle measurement. This requires a significantly shorter time than ToA ranging. Therefore, even when only ranging and not angle measurement are performed in the operations shown in FIGS. 2 and 3 , the effect of reducing the processing time of the ranging system 300 of the embodiment is the same as that of the comparative positioning system 30.

[0055] <Effects> As described above, the ranging method of the embodiment is a ranging method in a ranging system 300 including a ranging device 100 (an example of a first communication station) and multiple ranging devices 200A (an example of a second communication station) that measure the distance to the first communication station by bidirectionally transmitting ranging signals of multiple frequencies to and from the first communication station, and when the multiple second communication stations receive a request signal from the first communication station, they transmit ranging data indicating the measured distance to the first communication station. In this way, the ranging device 200A (an example of a second communication station) performs the calculation processing of ranging and angle measurement, thereby reducing the overall required time.

[0056] Therefore, it is possible to provide a distance measurement method that can reduce the processing time required for distance measurement when measuring distances between a plurality of communication stations (second communication stations).

[0057] Furthermore, the ranging device 100 (an example of a first communication station) performs a transmission / reception process to transmit ranging signals of multiple frequencies bidirectionally in turn with each of the multiple ranging devices 200A (an example of a second communication station), and each of the multiple second communication stations measures the distance to the first communication station based on the phase of the ranging signals of multiple frequencies in the transmission / reception process with the first communication station. Therefore, after performing a transmission / reception process in turn with each of the multiple ranging devices 200A (an example of a second communication station), the ranging device 100 can measure the distance based on the phase of the ranging signals traveling back and forth between the ranging device 100 (an example of a first communication station) and each of the multiple ranging devices 200A (an example of a second communication station).

[0058] Furthermore, the ranging device 100 (an example of a first communication station) transmits a request signal to each of the plurality of ranging devices 200A (an example of a second communication station) in turn, and the plurality of second communication stations transmit ranging data to the first communication station in the order in which the request signals were transmitted. Therefore, the ranging device 100 (an example of a first communication station) can obtain ranging data in turn from the plurality of ranging devices 200A (an example of a second communication station).

[0059] Furthermore, the ranging device 100 (an example of a first communication station) transmits a request signal to one of the second communication stations among the plurality of second communication stations, receives ranging data from the one second communication station, and then transmits a request signal to another one of the plurality of second communication stations and receives ranging data from the other one second communication station. Therefore, the transmission of the request signal to each second communication station and the reception of the ranging data are performed in a time-division manner, and the ranging device 100 (an example of a first communication station) can efficiently acquire ranging data.

[0060] Furthermore, the ranging device 100 (an example of a first communication station) performs a transmission / reception process to transmit ranging signals of multiple frequencies bidirectionally to each of the multiple second communication stations in turn, and then transmits a request signal and receives ranging data to each of the multiple second communication stations in a time-division manner according to the order in which the transmission / reception process was performed. Therefore, after the transmission / reception process with each second communication station is completed, the request signal can be transmitted and ranging data can be received, and the processing time can be shortened by effectively utilizing the communication time. Furthermore, since calculating distance takes time, the processing time can be shortened by transmitting a request signal and receiving ranging data to each of the multiple second communication stations in a time-division manner according to the order in which the transmission / reception process was performed, taking into account the time required for calculation and the order in which the calculation was performed.

[0061] Furthermore, the distance measuring device 100 (an example of a first communication station) transmits a request signal to each of the plurality of distance measuring devices 200A after the calculation processing time required for each of the plurality of distance measuring devices 200A to calculate the distance has elapsed. Therefore, at the timing when the calculation of the distance has been completed in each of the plurality of second communication stations, the request signal can be transmitted to each of the plurality of second communication stations in the order in which the transmission and reception processing was performed, and there is no waiting time for the calculation to be completed, making it possible to effectively utilize time and shorten the processing time.

[0062] The ranging system 300 includes a ranging device 100 (an example of a first communication station) and a plurality of second communication stations that measure the distance to the first communication station by transmitting ranging signals of multiple frequencies to and from the first communication station in both directions, and when the plurality of second communication stations receive a request signal from the first communication station, they transmit ranging data indicating the measured distance to the first communication station. In this way, the ranging device 200A (an example of a second communication station) performs the calculation processing of ranging and angle measurement, thereby reducing the overall required time.

[0063] Therefore, it is possible to provide a distance measuring system 300 that can reduce the processing time required for distance measurement when measuring distances between a plurality of communication stations (second communication stations).

[0064] <Modification> Fig. 4 is a diagram showing an example of the operation of a ranging system 300M according to a modified example of the embodiment. The ranging system 300M includes two ranging devices 100 (Anchors) and four ranging devices 200A (Tags 1 to 4), and each of the two ranging devices 100 performs processing for ranging and angle measurement with the four ranging devices 200A (Tags 1 to 4) in a time-division manner. Fig. 4 shows the operation of the two ranging devices 100 (Anchors) and the four ranging devices 200A (Tags 1 to 4) in chronological order. In Fig. 4, the vertical axis is the time axis, and the passage of time is shown from top to bottom.

[0065] The operation of the ranging system 300M is twice the operation of the ranging system 300 shown in Fig. 2 in the time axis direction, and the total processing time is 160 ms. Note that Fig. 4 does not show the transmission of the request signal and the reception of the ranging data and angle data performed between times t5 and t6 in Fig. 2, but these operations are performed in the same way.

[0066] Fig. 5 is a diagram showing the operation of a comparative positioning system 30M. The comparative positioning system 30M includes two anchors and Tags 1 to 4, and each of the two anchors performs processing for distance and angle measurement with Tags 1 to 4 in a time-division manner. Fig. 5 shows the operation of the two anchors and Tags 1 to 4 in chronological order. In Fig. 5, the vertical axis is the time axis, and the passage of time is shown from top to bottom.

[0067] The operation of the comparative positioning system 30M is twice the operation of the comparative positioning system 30 shown in FIG. 3 in the time axis direction, and the total processing time is 280 ms.

[0068] Thus, even when the number of anchors is increased to two, the distance measuring system 300M according to the modified embodiment can reduce the required time by 40% or more, from 280 ms to 160 ms, compared to the comparative positioning system 30M.

[0069] The above describes a ranging method and ranging system according to exemplary embodiments of the present disclosure. However, the present disclosure is not limited to the specifically disclosed embodiments, and various modifications and variations are possible without departing from the scope of the claims.

[0070] This international application claims priority based on Japanese Patent Application No. 2022-169070, filed on October 21, 2022, the entire contents of which are incorporated herein by reference. [Explanation of symbols]

[0071] 100 Distance measuring device (Anchor, an example of a first communication station) 110 Antenna 120 Communications Department 131 Main control unit 132 Transmission and reception processing unit 133 Ranging section 134 memory 200 smartphones 200A Distance Meter (Tag 1 to Tag 4, an example of a second communication station) 210 Antenna 220 Communications Department 231 Main control unit 232 Transmission and reception processing section 233 Ranging section 234 Angle measurement section 235 memory 300, 300M ranging system

Claims

1. a first communication station; a plurality of second communication stations that measure distances to the first communication stations by bidirectionally transmitting signals of a plurality of frequencies to the first communication stations; A ranging method in a ranging system including: When the plurality of second communication stations receive a request signal from the first communication station, the second communication stations transmit ranging data representing the measured distances to the first communication station; the first communication station transmits the request signal to each of the plurality of second communication stations in turn; the plurality of second communication stations transmit the ranging data to the first communication station in the order in which the request signals were transmitted; a ranging method in which the first communication station performs a transmission and reception process to transmit signals of the multiple frequencies bidirectionally with each of the multiple second communication stations in turn, and then transmits the request signal and receives the ranging data from each of the multiple second communication stations in a time-division manner in accordance with the order in which the transmission and reception process was performed.

2. the first communication station performs a transmission / reception process for transmitting signals of the plurality of frequencies bidirectionally to each of the plurality of second communication stations in turn; The ranging method according to claim 1 , wherein each of the second communication stations measures the distance to the first communication station based on phases of the signals of the multiple frequencies in the transmission / reception process with the first communication station.

3. 2. The ranging method according to claim 1, wherein the first communication station transmits the request signal to one second communication station among the plurality of second communication stations, receives the ranging data from the one second communication station, and then transmits the request signal to another second communication station among the plurality of second communication stations, and receives the ranging data from the other second communication station.

4. 4. The ranging method according to claim 1, wherein the first communication station transmits the request signal to each of the plurality of second communication stations after a calculation processing time required for each of the plurality of second communication stations to calculate the distance has elapsed.

5. a first communication station; a plurality of second communication stations that measure distances to the first communication stations by bidirectionally transmitting signals of a plurality of frequencies to the first communication stations; Including, When the plurality of second communication stations receive a request signal from the first communication station, the second communication stations transmit ranging data representing the measured distances to the first communication station; the first communication station transmits the request signal to each of the plurality of second communication stations in turn; the plurality of second communication stations transmit the ranging data to the first communication station in the order in which the request signals were transmitted; a ranging system in which the first communication station performs a transmission and reception process to transmit signals of the plurality of frequencies bidirectionally with each of the plurality of second communication stations in turn, and then transmits the request signal and receives the ranging data from each of the plurality of second communication stations in a time-division manner in accordance with the order in which the transmission and reception process was performed.

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