WO2023275923A1 - Receiver, communication system, and reception method - Google Patents

Receiver, communication system, and reception method Download PDF

Info

Publication number
WO2023275923A1
WO2023275923A1 PCT/JP2021/024327 JP2021024327W WO2023275923A1 WO 2023275923 A1 WO2023275923 A1 WO 2023275923A1 JP 2021024327 W JP2021024327 W JP 2021024327W WO 2023275923 A1 WO2023275923 A1 WO 2023275923A1
Authority
WO
WIPO (PCT)
Prior art keywords
receiving
transmitter
receiver
circuit
receiving antenna
Prior art date
Application number
PCT/JP2021/024327
Other languages
French (fr)
Japanese (ja)
Inventor
泰久 辻田
Original Assignee
太平洋工業株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 太平洋工業株式会社 filed Critical 太平洋工業株式会社
Priority to PCT/JP2021/024327 priority Critical patent/WO2023275923A1/en
Publication of WO2023275923A1 publication Critical patent/WO2023275923A1/en

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
    • H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
    • H04B7/08—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the receiving station

Definitions

  • the present disclosure relates to receivers, communication systems, and receiving methods.
  • the communication system disclosed in Patent Document 1 includes a transmitter and a receiver. Transmitters are provided on the wheels of the vehicle. A transmitter transmits a radio signal. The receiver is mounted on the vehicle. The receiver includes a receiving antenna and receiving circuitry. A receiving circuit acquires a radio signal via a receiving antenna.
  • a receiver that is arranged such that the relative positional relationship with the transmitter is constant.
  • the receiver comprises a plurality of receiving antennas configured to receive radio signals transmitted from the transmitter at predetermined transmission intervals, and configured to acquire the radio signals via the plurality of receiving antennas.
  • a switching circuit configured to selectively switch a receiving antenna connected to the receiving circuit among the plurality of receiving antennas; and a receiver control configured to control the switching circuit.
  • the receiver control device is configured to switch the receiving antenna connected to the receiving circuit according to the passage of time.
  • the receiving circuit can acquire the wireless signal by receiving the wireless signal with the receiving antenna connected to the receiving circuit.
  • a receiving circuit can acquire a radio signal by receiving the radio signal with at least one of the plurality of receiving antennas. Therefore, a situation in which the radio signal cannot be continuously received is less likely to occur.
  • the receiver control device may be configured to switch the receiving antenna connected to the receiving circuit at an interval longer than the transmission interval.
  • the receiver may further include a communication device that transmits information obtained from the radio signal to a server, and the server may include a database regarding the information.
  • a communication system comprising a transmitter and a receiver arranged such that the relative positional relationship with the transmitter is constant.
  • the transmitter includes a transmitter circuit configured to transmit a radio signal, and a transmitter controller configured to cause the transmitter circuit to transmit the radio signal at a predetermined transmission interval.
  • the receiver includes: a plurality of receiving antennas configured to receive the wireless signals; a receiving circuit configured to acquire the wireless signals via the plurality of receiving antennas; and the plurality of receiving antennas. a switching circuit configured to selectively switch a receiving antenna connected to the receiving circuit; and a receiver control device configured to control the switching circuit.
  • the receiver control device is configured to switch the receiving antenna connected to the receiving circuit according to the passage of time.
  • the receiving circuit can acquire the wireless signal. Therefore, a situation in which the radio signal cannot be continuously received is less likely to occur.
  • the receiver is attached to a ground-mounted structure, and the plurality of receiving antennas includes a first receiving antenna disposed on a first side with respect to the structure; a second receive antenna positioned on a second side opposite the first side to the structure, wherein the transmitter is positioned on the first side with respect to the structure 1 transmitter and a second transmitter located on said second side with respect to said structure.
  • the above communication system comprising a server, the receiver comprising a communication device configured to transmit information obtained from the radio signal to the server, the server comprising a database relating to the information. good too.
  • a receiving method is provided according to a third aspect of the present disclosure.
  • the receiving method includes disposing a receiver so that the relative positional relationship with the transmitter is constant, and setting a plurality of receiving antennas for receiving radio signals transmitted from the transmitter at predetermined transmission intervals.
  • a receiving circuit that acquires the radio signal via the plurality of receiving antennas, and a receiving antenna connected to the receiving circuit among the plurality of receiving antennas is changed over time. selectively switching in response.
  • the receiving circuit can acquire the wireless signal. Therefore, a situation in which the radio signal cannot be continuously received is less likely to occur.
  • FIG. 2 is a schematic configuration diagram of the communication system in FIG. 1;
  • FIG. 2 is a diagram showing the positional relationship between a first receiving antenna and a second receiving antenna provided in the receiver of FIG. 1;
  • FIG. 3 is a schematic diagram showing a database stored in the server of FIG. 2;
  • FIG. 3 is a flowchart of switching processing performed by the receiver control device of FIG. 2;
  • FIG. 3 is a time chart showing processing performed in the transmitter and receiver of FIG. 2;
  • FIG. FIG. 4 is a diagram showing the positional relationship between a first receiving antenna and a second receiving antenna;
  • FIG. 4 is a diagram showing directions of a first receiving antenna and a second receiving antenna;
  • the communication system 10 includes one or more transmitters 20, one or more receivers 30, and one or more servers 40.
  • a plurality of transmitters 20 are arranged along one or more lanes of the road R1.
  • the road R1 has two lanes L1 and L2.
  • the two lanes L1, L2 include a first lane L1 and a second lane L2.
  • the transmitters 20 are arranged along each of the first lane L1 and the second lane L2.
  • a plurality of transmitters 20 arranged along the first lane L1 constitute a first transmitter group TG1, and a plurality of transmitters 20 arranged along the second lane L2 constitute a second transmitter group TG2.
  • Road R1 is paved.
  • a vehicle V1 passes through the road R1.
  • the road R1 has a road surface RS1.
  • the road surface RS1, which is the ground, is the surface of the paved road R1.
  • the transmitters 20 are spaced apart from each other.
  • the transmitter 20 includes a battery 21, a sensor 22, a transmitter control device 23, a transmission circuit 26, and a transmission antenna 27.
  • the battery 21 is a power source for the transmitter 20.
  • Transmitter 20 is driven by power supplied from battery 21 .
  • the sensor 22 detects the state of the road surface RS1.
  • the sensor 22 of this embodiment is a temperature sensor that measures the temperature of the road surface RS1.
  • the transmitter control device 23 includes a processor 24 and a storage section 25 .
  • the processor 24 include an MPU (Micro Processing Unit), a CPU (Central Processing Unit), and a DSP (Digital Signal Processor).
  • the storage unit 25 includes RAM (Random Access Memory) and ROM (Read Only Memory). Storage unit 25 stores program code or instructions configured to cause processor 24 to perform processes.
  • the transmitter control device 23 may be configured by a hardware circuit such as ASIC or FPGA.
  • the processing circuitry, transmitter controller 23, may include one or more processors operating according to a computer program, one or more hardware circuits such as ASICs or FPGAs, or a combination thereof.
  • ROM and RAM or computer-readable media include any available media that can be accessed by a general purpose or special purpose computer.
  • the storage unit 25 stores an ID code indicating unique identification information of the corresponding transmitter 20 .
  • the transmitter control device 23 generates frames.
  • the transmitter control device 23 outputs the generated frame to the transmission circuit 26 .
  • a frame is digital data and is a data string of binary numbers.
  • a frame consists of data in a format defined by the protocol.
  • the frame format includes, for example, preamble, ID code, temperature data, status code, and error detection code. Temperature data is the measurement result of the sensor 22 .
  • the transmission circuit 26 transmits from the transmission antenna 27 a radio signal modulated according to the frame input from the transmitter control device 23 . Thereby, the measurement result of the sensor 22 is transmitted from the transmission circuit 26 .
  • a radio signal is a signal in a predetermined frequency band. Examples of frequency bands include the LF band, MF band, HF band, VHF band, UHF band, and 2.4 GHz band.
  • the transmitter controller 23 is configured to cause the transmitter circuit 26 to transmit radio signals at predetermined transmission intervals.
  • the predetermined transmission interval may be a predetermined constant interval, or may be an interval that randomly fluctuates between a predetermined upper limit and lower limit.
  • the receiver 30 is arranged so as to receive radio signals from the transmitter 20 .
  • the receiver 30 is arranged so as to receive radio signals from all the transmitters 20 of the first transmitter group TG1 and all the transmitters 20 of the second transmitter group TG2.
  • the receiver 30 is attached, for example, to a structure UP1 installed along the road R1. Examples of this type of structure UP1 include guardrails and utility poles.
  • the receiver 30 is attached to a structure UP1 provided along the first lane L1.
  • the receiver 30 includes a receiver control device 31, a receiving circuit 34, a plurality of receiving antennas 41 and 42, a switching circuit 35, and a communication device 38.
  • the receiver control device 31 includes a processor 32 and a storage section 33 .
  • Processors 32 may include, for example, MPUs, CPUs, and DSPs.
  • the storage unit 33 includes ROM and RAM. Storage unit 33 stores program code or instructions configured to cause processor 32 to perform processing.
  • the receiver control device 31 may be configured by a hardware circuit such as ASIC or FPGA.
  • the processing circuitry, receiver controller 31, may include one or more processors operating according to a computer program, one or more hardware circuits such as ASICs or FPGAs, or a combination thereof.
  • ROM and RAM or computer-readable media include any available media that can be accessed by a general purpose or special purpose computer.
  • the two receiving antennas 41 and 42 include a first receiving antenna 41 and a second receiving antenna 42 .
  • Each receiving antenna 41 , 42 receives the radio signal transmitted from each transmitter 20 .
  • any kind of antennas such as loop antennas and helical antennas may be used.
  • the first receiving antenna 41 and the second receiving antenna 42 may be of the same type, or may be of different types.
  • the first receiving antenna 41 and the second receiving antenna 42 are arranged at different positions. Two opposite directions along the first lane L1 and away from the structure UP1 are defined as a first direction and a second direction, respectively.
  • the first receiving antenna 41 is provided away from the structure UP1 in the first direction.
  • the second receiving antenna 42 is provided away from the structure UP1 in the second direction.
  • a first receiving antenna 41 is arranged on a first side with respect to the structure UP1.
  • a second receiving antenna 42 is arranged on a second side opposite the first side with respect to the structure UP1. It can be said that the first receiving antenna 41 and the second receiving antenna 42 are provided with the structure UP1 interposed therebetween.
  • the relative positional relationship between each transmitter 20 and receiver 30 is constant. Specifically, the relative positional relationship between each transmitter 20 and the two receiving antennas 41, 42 is constant.
  • the switching circuit 35 includes a first switch 36 and a second switch 37.
  • the first switch 36 and the second switch 37 for example, FETs (Field Effect Transistors) are used.
  • the first switch 36 is provided between the first receiving antenna 41 and the receiving circuit 34 .
  • a second switch 37 is provided between the second receiving antenna 42 and the receiving circuit 34 .
  • the first switch 36 is on, the first receiving antenna 41 is connected to the receiving circuit 34 .
  • the second switch 37 is on, the second receiving antenna 42 is connected to the receiving circuit 34 .
  • the receiver control device 31 selectively switches which of the first switch 36 and the second switch 37 is turned on. Therefore, when the first switch 36 is on, the second switch 37 is off.
  • the first switch 36 is off when the second switch 37 is on.
  • the switching circuit 35 selectively switches the receiving antenna connected to the receiving circuit 34 among the plurality of receiving antennas 41 and 42 .
  • the receiving circuit 34 acquires the radio signals received by the receiving antennas 41 and 42 .
  • the receiving circuit 34 demodulates the acquired radio signal to obtain data contained in the frame.
  • the receiving circuit 34 outputs data to the receiver control device 31 . Thereby, the receiver control device 31 acquires the measurement result of the sensor 22 .
  • the measurement results of sensor 22 are information obtained from radio signals.
  • the communication device 38 is a network device that includes a communication control unit, ports, etc., and is capable of transmitting and receiving information through the communication network NW.
  • the communication device 38 is connected to the server 40 via the communication network NW.
  • the server 40 has a database DB1.
  • the number of servers 40 may be plural or may be one.
  • the database DB1 is a set of data regarding the measurement results of the sensor 22. FIG.
  • the database DB1 created by the server 40 associates the measured temperature with the measurement time and the measurement position.
  • the measurement time is the time when the sensor 22 measures the temperature of the road surface RS1.
  • a measurement position is a position where each transmitter 20 is provided.
  • the position of each transmitter 20 is represented, for example, by coordinates in a coordinate system representing absolute positions on the earth.
  • a coordinate system of this kind can be, for example, a geographic coordinate system.
  • the location of each transmitter 20 may be specified from an ID code included in the radio signal. In order to realize this, information in which the ID code of each transmitter 20 is associated with the coordinates of the transmitter 20 is pre-stored in the server 40 or the receiver 30 . In this case, the receiver 30 or server 40 identifies the location of each transmitter 20 .
  • each transmitter 20 may transmit a radio signal including information indicating the position of each transmitter 20 .
  • the server 40 provides services to users. Services are provided as a cloud. A cloud is one form of computer usage that accumulates data and provides services. As a service, for example, provision of the database DB1 can be mentioned.
  • the server 40 may also provide the user with information on the road surface RS1 derived based on the database DB1.
  • the information on the road surface RS1 derived based on the database DB1 includes, for example, information on the freezing of the road surface RS1. Whether or not the road surface RS1 is frozen can be estimated from the measured temperature and the measured position. If the measured temperature is 0 degrees or less, it can be estimated that the measurement position associated with the measured temperature is frozen.
  • the server 40 or a management computer connected to the server 40 estimates whether the road surface RS1 is frozen.
  • the server 40 then provides the user with information on the road surface RS1 via the cloud.
  • the server 40 provides information on the road surface RS1 to the user through at least one of a web browser and an application.
  • Information about the road surface RS1 may be provided as text or as an image. Accordingly, when the measured temperature is 0 degrees or less, it is possible to alert the user that the road surface RS1 may be frozen.
  • the switching process performed by the receiver control device 31 will be explained.
  • the switching process is a process of switching the receiving antenna connected to the receiving circuit 34 between the first receiving antenna 41 and the second receiving antenna 42 .
  • the switching process is repeatedly performed at a predetermined control cycle.
  • step S10 the receiver control device 31 determines whether or not a predetermined time has passed.
  • the predetermined time is the elapsed time since the receiving antennas 41 and 42 were switched last time. If the determination result in step S10 is negative, the receiver control device 31 ends the switching process. The predetermined time is longer than the transmission interval of radio signals. If the determination result of step S10 is affirmative, the receiver control device 31 performs the process of step S11.
  • step S11 the receiver control device 31 switches between the receiving antennas 41 and 42. If the first switch 36 is on, the receiver control device 31 turns off the first switch 36 and turns on the second switch 37 . If the second switch 37 is on, the receiver control device 31 turns off the second switch 37 and turns on the first switch 36 .
  • the receiver control device 31 may provide a dead time during which both the switches 36 and 37 are turned off when switching between on and off of the switches 36 and 37 .
  • the receiving antenna connected to the receiving circuit 34 is alternately switched between the first receiving antenna 41 and the second receiving antenna 42 every predetermined time. As described above, in the receiving method of receiving the radio signal transmitted from the transmitter 20 using the receiver 30, the receiver control device 31 controls the receiving antenna 41, which is connected to the receiving circuit 34 as time elapses. Switch 42.
  • the transmitter 20 that is away from the structure UP1 in the first direction is the first transmitter 20A
  • the transmitter that is away from the structure UP1 in the second direction 20 is a second transmitter 20B.
  • a first transmitter 20A is arranged on a first side with respect to the structure UP1.
  • a second transmitter 20B is arranged on a second side opposite the first side with respect to the structure UP1.
  • a radio signal transmitted from the first transmitter 20A is easily received by the first receiving antenna 41 .
  • radio signals transmitted from the second transmitter 20B are difficult to be received by the first receiving antenna 41 . This is because the structure UP1 between the second transmitter 20B and the first receiving antenna 41 may block radio signals.
  • radio signals transmitted from the second transmitter 20B are likely to be received by the second receiving antenna 42 .
  • the receiving circuit 34 can acquire the radio signal. Thereby, the receiver control device 31 can obtain the measurement result of the sensor 22 . Specifically, when the first receiving antenna 41 is connected to the receiving circuit 34, it is difficult to receive the radio signal from the second transmitter 20B. Wireless signal may not be acquired. However, since the receiving antennas 41 and 42 connected to the receiving circuit 34 are switched over time, when the second receiving antenna 42 is connected to the receiving circuit 34, the radio signal from the second transmitter 20B is received. easier to do. This makes it less likely that the radio signal from each transmitter 20 cannot be received continuously.
  • the reception period R11 by the first reception antenna 41 and the reception period R21 by the second reception antenna 42 are switched at a predetermined time T1. Since the predetermined time T1 is longer than the radio signal transmission interval T2, each transmitter 20 transmits a radio signal at least once during one reception period R11, R21. During the reception period R11 of the first reception antenna 41, it is easy to receive the radio signal Se1 from the first transmitter 20A. During the reception period R21 of the second reception antenna 42, the radio signal Se2 from the second transmitter 20B is likely to be received. Therefore, it is unlikely that the radio signals Se1 and Se2 from the transmitters 20 cannot be received continuously.
  • the receiver 30 includes a plurality of receiving antennas 41 and 42.
  • the receiving circuit 34 can acquire the radio signal. Therefore, the receiver 30 can easily receive the radio signal transmitted from the transmitter 20 .
  • the position of the reception antenna is determined so that radio signals from all transmitters 20 can be received. is difficult.
  • by providing a plurality of receiving antennas 41 and 42 it is sufficient that at least one of the plurality of receiving antennas 41 and 42 can receive a radio signal, and a plurality of transmitters can be used without increasing the number of receivers 30. 20 can receive radio signals.
  • the receiving antenna connected to the receiving circuit 34 is switched among the plurality of receiving antennas 41 and 42 according to the passage of time.
  • the combiner can reduce the received voltage of the radio signal. In this embodiment, it is possible to avoid a drop in the received voltage caused by the coupler.
  • the receiving antenna having the higher reception level among the plurality of receiving antennas 41 and 42 is connected to the receiving circuit 34 . Therefore, when trying to receive radio signals using the diversity system, it is necessary to detect the reception levels of the reception antennas 41 and 42 . In order to detect the reception level, it is necessary to lengthen the transmission time of the radio signal. Therefore, when using the diversity method, it is necessary to lengthen the transmission time of the radio signal, and there is a possibility that the life of the battery 21 of the transmitter 20 will be shortened.
  • the receiving antennas 41 and 42 are simply switched according to the passage of time. Therefore, it is not necessary to detect the reception levels of the receiving antennas 41 and 42, and it is not necessary to lengthen the transmission time of the radio signal in order to detect the reception levels. Therefore, the service life of the battery 21 can be extended.
  • the receiver control device 31 switches the receiving antenna connected to the receiving circuit 34 at intervals longer than the radio signal transmission interval. If the reception antennas 41 and 42 are switched at an interval shorter than the radio signal transmission interval, there is a possibility that the reception antennas 41 and 42 are switched during reception of the radio signal. On the other hand, by switching the reception antennas 41 and 42 at intervals longer than the transmission interval of the radio signal, it is possible to suppress the switching between the reception antennas 41 and 42 during reception of the radio signal.
  • the receiver 30 includes a communication device 38 . Via communication device 38 , the measurements of sensor 22 can be transmitted to server 40 . Thereby, the measurement results can be stored in the server 40 .
  • the measurement result of the sensor 22 is transmitted from the transmitter 20 to the receiver 30, and further transmitted from the receiver 30 to the server 40.
  • the receiver 30 receives the measurement results of a plurality of transmitters 20, and the receiver 30 transmits the measurement results to the server 40, so that only the receiver 30 needs to be provided with the communication device 38.
  • FIG. Therefore, the manufacturing cost of the transmitters 20 can be reduced compared to the case where the communication device 38 is provided for each transmitter 20 . Also, the communication cost for communication with the server 40 can be reduced compared to the case where the communication device 38 is provided for each transmitter 20 .
  • the receiving antenna connected to the receiving circuit 34 may be switched in order as time elapses.
  • the receiving antenna connected to the receiving circuit 34 may be randomly switched over time.
  • the interval at which the receiving antennas 41 and 42 connected to the receiving circuit 34 are switched may be shorter than the interval at which the radio signals are transmitted.
  • the interval at which the receiving antennas 41 and 42 connected to the receiving circuit 34 are switched may be random. Even in this case, the interval at which the receiving antennas 41 and 42 connected to the receiving circuit 34 are switched may be longer than the radio signal transmission interval.
  • the switching circuit 35 may use an operational amplifier, a buffer, a mechanical relay, or a MEMS (Micro Electro Mechanical Systems) relay.
  • the first receiving antenna 41 and the second receiving antenna 42 may be provided apart from each other in the facing directions of the two lanes L1 and L2.
  • the distance from the transmitter 20 of the second transmitter group TG2 to the second receiving antenna 42 is shorter than the distance from the transmitter 20 of the second transmitter group TG2 to the first receiving antenna 41.
  • the second receiving antenna 42 facilitates reception of radio signals transmitted from the transmitters 20 of the second transmitter group TG2.
  • the second receiving antenna 42 is provided at a higher position than the first receiving antenna 41. If the second receiving antenna 42 is provided at a low position, there is a risk that the reception of the radio signal by the second receiving antenna 42 will be hindered by the vehicle V1 becoming an obstacle. By providing the second receiving antenna 42 at a position higher than the height assumed to be reached by the top of the vehicle V1, it is possible to prevent the vehicle V1 from obstructing the reception of the radio signal.
  • the directions of the first receiving antenna 41 and the second receiving antenna 42 may be different.
  • the plane of polarization of the first receiving antenna 41 and the plane of polarization of the second receiving antenna 42 may be different.
  • the types of the first receiving antenna 41 and the second receiving antenna 42 may be different.
  • the first receiving antenna 41 may be a loop antenna and the second receiving antenna 42 may be a helical antenna.
  • Different types of antennas have different planes of polarization and directivities. As a result, even if the first receiving antenna 41 and the second receiving antenna 42 are provided at the same position, the transmitters 20 that are likely to receive radio signals are different between the first receiving antenna 41 and the second receiving antenna 42. . Therefore, the degree of freedom of arrangement of the first receiving antenna 41 and the second receiving antenna 42 can be increased.
  • the transmitter 20 may be provided on unpaved ground.
  • the transmitter 20 may include a pressure sensor as the sensor 22 .
  • a pressure sensor is provided to measure the atmospheric pressure.
  • the pressure sensor measurement results may be transmitted to the server 40 .
  • the measurement results of the pressure sensor can be used, for example, for weather forecasting.
  • the transmitter 20 may include an acceleration sensor as the sensor 22 .
  • the acceleration sensor measures acceleration applied to the acceleration sensor.
  • the transmitter 20 is impacted.
  • a larger acceleration is applied to the acceleration sensor than when the vehicle V1 does not pass over the transmitter 20 . Therefore, when an accident occurs, checking the measurement result of the acceleration sensor at the time when the accident occurred can be useful for grasping the route that the vehicle V1 has passed.
  • the transmitter 20 may be provided at any location.
  • the transmitter 20 may be provided for the target whose temperature is to be measured.
  • a transmitter 20 may be provided above the traffic light. In this case, it is possible to determine whether or not snow is piled up on the traffic signal from the measurement result of the temperature sensor.
  • the transmitter 20 may be provided on the target whose tilt is to be detected.
  • an acceleration sensor is provided to detect gravitational acceleration. When the acceleration sensor tilts, the acceleration detected by the acceleration sensor changes. For this reason, if the transmitter 20 is provided for the target whose tilt is to be detected, the tilt of the target can be detected by the receiver 30 .
  • the transmitter 20 may be provided above the traffic light so that the receiver 30 can determine whether the traffic light has tilted.
  • the communication system 10 may not include the server 40 .
  • the receiver 30 may be configured to receive measurement results transmitted from multiple transmitters 20 and store the measurement results.
  • the communication system 10 may include at least one of a display section and a light emitting section. At least one of the display unit and the light emitting unit may be included in the receiver 30 or may be provided separately from the receiver 30 .
  • the receiver control device 31 may estimate the state of the road surface RS1 from the measurement result of the sensor 22, and control at least one of the display unit and the light emitting unit according to the state of the road surface RS1. If the sensor 22 is a temperature sensor, the receiver controller 31 may estimate whether the road surface RS1 is frozen.
  • the receiver control device 31 may estimate that the road surface RS1 is frozen when the measurement result of the sensor 22 is 0 degrees or less. Then, when the receiver control device 31 estimates that the road surface RS1 is frozen, it performs display on the display unit and light emission from the light emitting unit. As a result, the attention of people around the receiver 30 can be called.
  • ⁇ There may be only one transmitter 20 . Even in this case, even if one of the receiving antennas 41 and 42 becomes difficult to receive the radio signal due to the influence of an obstacle such as the vehicle V1, the other receiving antenna 41 or 42 receives the radio signal. be able to. Therefore, the influence of obstacles such as the vehicle V1 can be reduced.
  • DB1...Database 10...Communication system, 20...Transmitter, 23...Transmitter control device, 26...Transmitting circuit, 30...Receiver, 31...Receiver control device, 34...Receiving circuit, 35...Switching circuit, 38... Communication device, 40... Server, 41, 42... Receiving antenna.

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Arrangements For Transmission Of Measured Signals (AREA)

Abstract

A receiver (30) is disposed so as to have a uniform relative position to a transmitter (20). The receiver (30) comprises: a plurality of reception antennas (41, 42) that receive wireless signals transmitted from the transmitter (20) at prescribed transmission intervals; a reception circuit (34) that obtains wireless signals via the plurality of reception antennas (41, 42); a switching circuit (35) that selectively switches the reception antenna that connects to the reception circuit (34), among the plurality of reception antennas (41, 42); and a receiver control device (31) that is configured so as to control the switching circuit (35). The receiver control device (31) is configured so as to switch the reception antenna (41, 42) that is connected to the reception circuit (34), over time.

Description

受信機、通信システム及び受信方法Receiver, communication system and receiving method
　本開示は、受信機、通信システム及び受信方法に関する。 The present disclosure relates to receivers, communication systems, and receiving methods.
　特許文献１に開示の通信システムは、送信機と、受信機と、を備える。送信機は、車両の車輪に設けられている。送信機は、無線信号を送信する。受信機は、車両に搭載されている。受信機は、受信アンテナと、受信回路と、を備える。受信回路は、受信アンテナを介して無線信号を取得する。 The communication system disclosed in Patent Document 1 includes a transmitter and a receiver. Transmitters are provided on the wheels of the vehicle. A transmitter transmits a radio signal. The receiver is mounted on the vehicle. The receiver includes a receiving antenna and receiving circuitry. A receiving circuit acquires a radio signal via a receiving antenna.
特開２０１５－１５０９８０号公報JP 2015-150980 A
　送信機と受信機との相対的位置関係によっては、送信機から送信された無線信号を受信アンテナで受信しにくい。特許文献１のように、送信機が車輪に設けられている場合、車輪の回転によって送信機と受信機との相対的位置関係が変化する。このため、特許文献１の通信システムでは、送信機から送信された無線信号を継続して受信できない事態が生じにくい。一方で、送信機と受信機との相対的位置関係が変化しない場合、送信機から送信された無線信号を受信回路が継続して取得できない事態が生じ得る。 Depending on the relative positional relationship between the transmitter and receiver, it may be difficult for the receiving antenna to receive the radio signal transmitted from the transmitter. As in Patent Document 1, when the transmitter is provided on the wheel, the rotation of the wheel changes the relative positional relationship between the transmitter and the receiver. Therefore, in the communication system of Patent Document 1, it is unlikely that the radio signal transmitted from the transmitter cannot be received continuously. On the other hand, if the relative positional relationship between the transmitter and the receiver does not change, a situation may arise in which the receiving circuit cannot continuously acquire the radio signal transmitted from the transmitter.
　本開示の第一の態様によれば、送信機との相対的位置関係が一定となるように配置される受信機が提供される。前記受信機は、前記送信機から所定の送信間隔で送信される無線信号を受信するように構成された複数の受信アンテナと、前記複数の受信アンテナを介して前記無線信号を取得するように構成された受信回路と、前記複数の受信アンテナのうち前記受信回路に接続する受信アンテナを選択的に切り替えるように構成された切替回路と、前記切替回路を制御するように構成された受信機用制御装置と、を備える。前記受信機用制御装置は、時間経過に応じて前記受信回路に接続する前記受信アンテナを切り替えるように構成されている。 According to the first aspect of the present disclosure, there is provided a receiver that is arranged such that the relative positional relationship with the transmitter is constant. The receiver comprises a plurality of receiving antennas configured to receive radio signals transmitted from the transmitter at predetermined transmission intervals, and configured to acquire the radio signals via the plurality of receiving antennas. a switching circuit configured to selectively switch a receiving antenna connected to the receiving circuit among the plurality of receiving antennas; and a receiver control configured to control the switching circuit. a device; The receiver control device is configured to switch the receiving antenna connected to the receiving circuit according to the passage of time.
　時間経過に応じて受信回路に接続される受信アンテナを切り替えているため、受信回路に接続された受信アンテナで無線信号を受信することで、受信回路に無線信号を取得させることができる。複数の受信アンテナの少なくとも１つで無線信号を受信することで、受信回路に無線信号を取得させることができる。このため、無線信号を継続的に受信できない事態が生じにくい。 Since the receiving antenna connected to the receiving circuit is switched over time, the receiving circuit can acquire the wireless signal by receiving the wireless signal with the receiving antenna connected to the receiving circuit. A receiving circuit can acquire a radio signal by receiving the radio signal with at least one of the plurality of receiving antennas. Therefore, a situation in which the radio signal cannot be continuously received is less likely to occur.
　上記受信機について、前記受信機用制御装置は、前記送信間隔よりも長い間隔で前記受信回路に接続する前記受信アンテナを切り替えるように構成されていてもよい。 Regarding the receiver, the receiver control device may be configured to switch the receiving antenna connected to the receiving circuit at an interval longer than the transmission interval.
　上記受信機について、前記無線信号から得られた情報をサーバーに送信する通信装置をさらに備え、前記サーバーは、前記情報に関するデータベースを備えていてもよい。 The receiver may further include a communication device that transmits information obtained from the radio signal to a server, and the server may include a database regarding the information.
　本開示の第二の態様によれば、送信機と、前記送信機との相対的位置関係が一定となるように配置される受信機と、を備えた通信システムが提供される。前記送信機は、無線信号を送信するように構成された送信回路と、前記無線信号を所定の送信間隔で前記送信回路から送信させるように構成された送信機用制御装置と、を備える。前記受信機は、前記無線信号を受信するように構成された複数の受信アンテナと、前記複数の受信アンテナを介して前記無線信号を取得するように構成された受信回路と、前記複数の受信アンテナのうち前記受信回路に接続する受信アンテナを選択的に切り替えるように構成された切替回路と、前記切替回路を制御するように構成された受信機用制御装置と、を備える。前記受信機用制御装置は、時間経過に応じて前記受信回路に接続する前記受信アンテナを切り替えるように構成されている。 According to a second aspect of the present disclosure, there is provided a communication system comprising a transmitter and a receiver arranged such that the relative positional relationship with the transmitter is constant. The transmitter includes a transmitter circuit configured to transmit a radio signal, and a transmitter controller configured to cause the transmitter circuit to transmit the radio signal at a predetermined transmission interval. The receiver includes: a plurality of receiving antennas configured to receive the wireless signals; a receiving circuit configured to acquire the wireless signals via the plurality of receiving antennas; and the plurality of receiving antennas. a switching circuit configured to selectively switch a receiving antenna connected to the receiving circuit; and a receiver control device configured to control the switching circuit. The receiver control device is configured to switch the receiving antenna connected to the receiving circuit according to the passage of time.
　複数の受信アンテナの少なくとも１つで無線信号を受信することで、受信回路に無線信号を取得させることができる。このため、無線信号を継続的に受信できない事態が生じにくい。 By receiving a wireless signal with at least one of the plurality of receiving antennas, the receiving circuit can acquire the wireless signal. Therefore, a situation in which the radio signal cannot be continuously received is less likely to occur.
　上記通信システムについて、前記受信機は地面に設置された構造物に取り付けられ、前記複数の受信アンテナは、前記構造物に対して第１の側に配置される第１受信アンテナと、前記構造物に対して、第１の側とは反対の第２の側に配置される第２受信アンテナと、を含み、前記送信機は、前記構造物に対して前記第１の側に配置される第１送信機と、前記構造物に対して前記第２の側に配置される第２送信機と、を含んでいてもよい。 For the above communication system, the receiver is attached to a ground-mounted structure, and the plurality of receiving antennas includes a first receiving antenna disposed on a first side with respect to the structure; a second receive antenna positioned on a second side opposite the first side to the structure, wherein the transmitter is positioned on the first side with respect to the structure 1 transmitter and a second transmitter located on said second side with respect to said structure.
　上記通信システムについて、サーバーを備え、前記受信機は、前記無線信号から得られた情報を前記サーバーに送信するように構成された通信装置を備え、前記サーバーは、前記情報に関するデータベースを備えていてもよい。 The above communication system comprising a server, the receiver comprising a communication device configured to transmit information obtained from the radio signal to the server, the server comprising a database relating to the information. good too.
　本開示の第三の態様によれば、受信方法が提供される。受信方法は、送信機との相対的位置関係が一定となるように受信機を配置することと、前記送信機から所定の送信間隔で送信される無線信号を受信する複数の受信アンテナを前記受信機に設けることと、前記複数の受信アンテナを介して前記無線信号を取得する受信回路を前記受信機に設けることと、前記複数の受信アンテナのうち前記受信回路に接続する受信アンテナを時間経過に応じて選択的に切り替えることと、を備える。 A receiving method is provided according to a third aspect of the present disclosure. The receiving method includes disposing a receiver so that the relative positional relationship with the transmitter is constant, and setting a plurality of receiving antennas for receiving radio signals transmitted from the transmitter at predetermined transmission intervals. a receiving circuit that acquires the radio signal via the plurality of receiving antennas, and a receiving antenna connected to the receiving circuit among the plurality of receiving antennas is changed over time. selectively switching in response.
　複数の受信アンテナの少なくとも１つで無線信号を受信することで、受信回路に無線信号を取得させることができる。このため、無線信号を継続的に受信できない事態が生じにくい。 By receiving a wireless signal with at least one of the plurality of receiving antennas, the receiving circuit can acquire the wireless signal. Therefore, a situation in which the radio signal cannot be continuously received is less likely to occur.
通信システムを示す模式図。Schematic diagram showing a communication system. 図１の通信システムの概略構成図。FIG. 2 is a schematic configuration diagram of the communication system in FIG. 1; 図１の受信機が備える第１受信アンテナ及び第２受信アンテナの位置関係を示す図。FIG. 2 is a diagram showing the positional relationship between a first receiving antenna and a second receiving antenna provided in the receiver of FIG. 1; 図２のサーバーに記憶されたデータベースを示す模式図。FIG. 3 is a schematic diagram showing a database stored in the server of FIG. 2; 図２の受信機用制御装置が行う切替処理のフローチャート。FIG. 3 is a flowchart of switching processing performed by the receiver control device of FIG. 2; FIG. 図２の送信機及び受信機で行われる処理を示すタイムチャート。FIG. 3 is a time chart showing processing performed in the transmitter and receiver of FIG. 2; FIG. 第１受信アンテナ及び第２受信アンテナの位置関係を示す図。FIG. 4 is a diagram showing the positional relationship between a first receiving antenna and a second receiving antenna; 第１受信アンテナ及び第２受信アンテナの向きを示す図。FIG. 4 is a diagram showing directions of a first receiving antenna and a second receiving antenna;
　以下、受信機、通信システム及び受信方法の一実施形態について説明する。 An embodiment of a receiver, a communication system, and a receiving method will be described below.
　図１に示すように、通信システム１０は、１つ以上の送信機２０と、１つ以上の受信機３０と、１つ以上のサーバー４０と、を備える。 As shown in FIG. 1, the communication system 10 includes one or more transmitters 20, one or more receivers 30, and one or more servers 40.
　複数の送信機２０が、道路Ｒ１の１つ以上の車線に沿って配置されている。図１に示す例では、道路Ｒ１は２つの車線Ｌ１，Ｌ２を備える。２つの車線Ｌ１，Ｌ２は、第１車線Ｌ１及び第２車線Ｌ２を含む。送信機２０は、第１車線Ｌ１及び第２車線Ｌ２の各々に沿って配置されている。第１車線Ｌ１に沿って配置された複数の送信機２０は第１送信機群ＴＧ１であり、第２車線Ｌ２に沿って配置さられた複数の送信機２０は第２送信機群ＴＧ２である。道路Ｒ１は、舗装されている。道路Ｒ１には、車両Ｖ１が通過する。道路Ｒ１は、路面ＲＳ１を備える。地面である路面ＲＳ１は、舗装された道路Ｒ１の表面である。送信機２０は、互いに間隔を空けて配置されている。 A plurality of transmitters 20 are arranged along one or more lanes of the road R1. In the example shown in FIG. 1, the road R1 has two lanes L1 and L2. The two lanes L1, L2 include a first lane L1 and a second lane L2. The transmitters 20 are arranged along each of the first lane L1 and the second lane L2. A plurality of transmitters 20 arranged along the first lane L1 constitute a first transmitter group TG1, and a plurality of transmitters 20 arranged along the second lane L2 constitute a second transmitter group TG2. . Road R1 is paved. A vehicle V1 passes through the road R1. The road R1 has a road surface RS1. The road surface RS1, which is the ground, is the surface of the paved road R1. The transmitters 20 are spaced apart from each other.
　図２に示すように、送信機２０は、バッテリ２１と、センサ２２と、送信機用制御装置２３と、送信回路２６と、送信アンテナ２７と、を備える。 As shown in FIG. 2, the transmitter 20 includes a battery 21, a sensor 22, a transmitter control device 23, a transmission circuit 26, and a transmission antenna 27.
　バッテリ２１は、送信機２０の電力源である。送信機２０は、バッテリ２１から供給される電力によって駆動する。 The battery 21 is a power source for the transmitter 20. Transmitter 20 is driven by power supplied from battery 21 .
　センサ２２は、路面ＲＳ１の状態を検出する。本実施形態のセンサ２２は、路面ＲＳ１の温度を測定する温度センサである。 The sensor 22 detects the state of the road surface RS1. The sensor 22 of this embodiment is a temperature sensor that measures the temperature of the road surface RS1.
　送信機用制御装置２３は、プロセッサ２４と、記憶部２５と、を備える。プロセッサ２４としては、例えば、MPU(Micro Processing Unit)、CPU(Central Processing Unit)、及びDSP(Digital Signal Processor)を挙げることができる。記憶部２５は、RAM（Random Access Memory）及びROM（Read Only Memory）を含む。記憶部２５は、処理をプロセッサ２４に実行させるように構成されたプログラムコード又は指令を格納している。送信機用制御装置２３は、ASICやFPGA等のハードウェア回路によって構成されていてもよい。処理回路である送信機用制御装置２３は、コンピュータプログラムに従って動作する１つ以上のプロセッサ、ASICやFPGA等の１つ以上のハードウェア回路、或いは、それらの組み合わせを含み得る。ROM及びRAMすなわちコンピュータ可読媒体は、汎用または専用のコンピュータでアクセスできるあらゆる利用可能な媒体を含む。記憶部２５は、対応する送信機２０の固有の識別情報を示すＩＤコードを記憶している。 The transmitter control device 23 includes a processor 24 and a storage section 25 . Examples of the processor 24 include an MPU (Micro Processing Unit), a CPU (Central Processing Unit), and a DSP (Digital Signal Processor). The storage unit 25 includes RAM (Random Access Memory) and ROM (Read Only Memory). Storage unit 25 stores program code or instructions configured to cause processor 24 to perform processes. The transmitter control device 23 may be configured by a hardware circuit such as ASIC or FPGA. The processing circuitry, transmitter controller 23, may include one or more processors operating according to a computer program, one or more hardware circuits such as ASICs or FPGAs, or a combination thereof. ROM and RAM or computer-readable media include any available media that can be accessed by a general purpose or special purpose computer. The storage unit 25 stores an ID code indicating unique identification information of the corresponding transmitter 20 .
　送信機用制御装置２３は、フレームを生成する。送信機用制御装置２３は、生成したフレームを送信回路２６に出力する。フレームは、デジタルデータであり２進数のデータ列である。フレームは、プロトコルで規定されたフォーマットのデータで構成されている。フレームのフォーマットは、例えば、プリアンブル、ＩＤコード、温度データ、ステータスコード、及び誤り検出符号を含む。温度データは、センサ２２の測定結果である。 The transmitter control device 23 generates frames. The transmitter control device 23 outputs the generated frame to the transmission circuit 26 . A frame is digital data and is a data string of binary numbers. A frame consists of data in a format defined by the protocol. The frame format includes, for example, preamble, ID code, temperature data, status code, and error detection code. Temperature data is the measurement result of the sensor 22 .
　送信回路２６は、送信機用制御装置２３から入力されたフレームに応じた変調を行った無線信号を送信アンテナ２７から送信する。これにより、送信回路２６からセンサ２２の測定結果が送信される。無線信号は、所定の周波数帯の信号である。周波数帯としては、例えば、ＬＦ帯、ＭＦ帯、ＨＦ帯、ＶＨＦ帯、ＵＨＦ帯、及び２．４ＧＨｚ帯を挙げることができる。送信機用制御装置２３は、所定の送信間隔で送信回路２６から無線信号を送信させるように構成されている。所定の送信間隔は、予め定められた一定の間隔であってもよいし、予め定められた上限と下限との間でランダムに変動する間隔であってもよい。 The transmission circuit 26 transmits from the transmission antenna 27 a radio signal modulated according to the frame input from the transmitter control device 23 . Thereby, the measurement result of the sensor 22 is transmitted from the transmission circuit 26 . A radio signal is a signal in a predetermined frequency band. Examples of frequency bands include the LF band, MF band, HF band, VHF band, UHF band, and 2.4 GHz band. The transmitter controller 23 is configured to cause the transmitter circuit 26 to transmit radio signals at predetermined transmission intervals. The predetermined transmission interval may be a predetermined constant interval, or may be an interval that randomly fluctuates between a predetermined upper limit and lower limit.
　図１に示すように、受信機３０は、送信機２０からの無線信号を受信できるように配置されている。詳細にいえば、受信機３０は、第１送信機群ＴＧ１の全ての送信機２０、及び第２送信機群ＴＧ２の全ての送信機２０の無線信号を受信できるように配置されている。受信機３０は、例えば、道路Ｒ１に沿って設置された構造物ＵＰ１に取り付けられている。この種の構造物ＵＰ１としては、例えば、ガードレール、及び電柱が挙げられる。本実施形態では、受信機３０は、第１車線Ｌ１に沿って設けられた構造物ＵＰ１に取り付けられている。 As shown in FIG. 1, the receiver 30 is arranged so as to receive radio signals from the transmitter 20 . Specifically, the receiver 30 is arranged so as to receive radio signals from all the transmitters 20 of the first transmitter group TG1 and all the transmitters 20 of the second transmitter group TG2. The receiver 30 is attached, for example, to a structure UP1 installed along the road R1. Examples of this type of structure UP1 include guardrails and utility poles. In this embodiment, the receiver 30 is attached to a structure UP1 provided along the first lane L1.
　図２に示すように、受信機３０は、受信機用制御装置３１と、受信回路３４と、複数の受信アンテナ４１，４２と、切替回路３５と、通信装置３８と、を備える。 As shown in FIG. 2, the receiver 30 includes a receiver control device 31, a receiving circuit 34, a plurality of receiving antennas 41 and 42, a switching circuit 35, and a communication device 38.
　受信機用制御装置３１は、プロセッサ３２と、記憶部３３と、を備える。プロセッサ３２としては、例えば、MPU、CPU、及びDSPを挙げることができる。記憶部３３は、ROM及びRAMを含む。記憶部３３は、処理をプロセッサ３２に実行させるように構成されたプログラムコード又は指令を格納している。受信機用制御装置３１は、ASICやFPGA等のハードウェア回路によって構成されていてもよい。処理回路である受信機用制御装置３１は、コンピュータプログラムに従って動作する１つ以上のプロセッサ、ASICやFPGA等の１つ以上のハードウェア回路、或いは、それらの組み合わせを含み得る。ROM及びRAMすなわちコンピュータ可読媒体は、汎用または専用のコンピュータでアクセスできるあらゆる利用可能な媒体を含む。 The receiver control device 31 includes a processor 32 and a storage section 33 . Processors 32 may include, for example, MPUs, CPUs, and DSPs. The storage unit 33 includes ROM and RAM. Storage unit 33 stores program code or instructions configured to cause processor 32 to perform processing. The receiver control device 31 may be configured by a hardware circuit such as ASIC or FPGA. The processing circuitry, receiver controller 31, may include one or more processors operating according to a computer program, one or more hardware circuits such as ASICs or FPGAs, or a combination thereof. ROM and RAM or computer-readable media include any available media that can be accessed by a general purpose or special purpose computer.
　本実施形態において、受信アンテナ４１，４２は２つ設けられている。２つの受信アンテナ４１，４２は、第１受信アンテナ４１及び第２受信アンテナ４２を含む。各受信アンテナ４１，４２は、各送信機２０から送信された無線信号を受信する。受信アンテナ４１，４２としては、ループアンテナやヘリカルアンテナ等、どのような種類のアンテナを用いていてもよい。第１受信アンテナ４１と第２受信アンテナ４２とは、同一種類のアンテナであってもよいし、異なる種類のアンテナであってもよい。 In this embodiment, two receiving antennas 41 and 42 are provided. The two receiving antennas 41 , 42 include a first receiving antenna 41 and a second receiving antenna 42 . Each receiving antenna 41 , 42 receives the radio signal transmitted from each transmitter 20 . As the receiving antennas 41 and 42, any kind of antennas such as loop antennas and helical antennas may be used. The first receiving antenna 41 and the second receiving antenna 42 may be of the same type, or may be of different types.
　図３に示すように、第１受信アンテナ４１と、第２受信アンテナ４２とは、異なる位置に配置されている。第１車線Ｌ１に沿う方向であって構造物ＵＰ１から離れる互いに逆向きの２つの方向をそれぞれ第１方向及び第２方向とする。第１受信アンテナ４１は、構造物ＵＰ１から第１方向に離れて設けられている。第２受信アンテナ４２は、構造物ＵＰ１から第２方向に離れて設けられている。第１受信アンテナ４１は、構造物ＵＰ１に対して第１の側に配置されている。第２受信アンテナ４２は、構造物ＵＰ１に対して、第１の側とは反対の第２の側に配置されている。第１受信アンテナ４１と第２受信アンテナ４２とは、構造物ＵＰ１を間において設けられているといえる。各送信機２０と受信機３０との相対的位置関係は一定である。詳細にいえば、各送信機２０と２つの受信アンテナ４１，４２との相対的位置関係は一定である。 As shown in FIG. 3, the first receiving antenna 41 and the second receiving antenna 42 are arranged at different positions. Two opposite directions along the first lane L1 and away from the structure UP1 are defined as a first direction and a second direction, respectively. The first receiving antenna 41 is provided away from the structure UP1 in the first direction. The second receiving antenna 42 is provided away from the structure UP1 in the second direction. A first receiving antenna 41 is arranged on a first side with respect to the structure UP1. A second receiving antenna 42 is arranged on a second side opposite the first side with respect to the structure UP1. It can be said that the first receiving antenna 41 and the second receiving antenna 42 are provided with the structure UP1 interposed therebetween. The relative positional relationship between each transmitter 20 and receiver 30 is constant. Specifically, the relative positional relationship between each transmitter 20 and the two receiving antennas 41, 42 is constant.
　図２に示すように、切替回路３５は、第１スイッチ３６と、第２スイッチ３７と、を備える。第１スイッチ３６及び第２スイッチ３７としては、例えば、FET(Field Effect Transistor)が用いられる。第１スイッチ３６は、第１受信アンテナ４１と受信回路３４との間に設けられている。第２スイッチ３７は、第２受信アンテナ４２と受信回路３４との間に設けられている。第１スイッチ３６がオンの場合、第１受信アンテナ４１が受信回路３４に接続される。第２スイッチ３７がオンの場合、第２受信アンテナ４２が受信回路３４に接続される。受信機用制御装置３１は、第１スイッチ３６及び第２スイッチ３７のうちオンにするスイッチを選択的に切り替える。従って、第１スイッチ３６がオンのときには第２スイッチ３７はオフである。第２スイッチ３７がオンのときには第１スイッチ３６はオフである。これにより、切替回路３５は、複数の受信アンテナ４１，４２のうち受信回路３４に接続する受信アンテナを選択的に切り替える。 As shown in FIG. 2, the switching circuit 35 includes a first switch 36 and a second switch 37. As the first switch 36 and the second switch 37, for example, FETs (Field Effect Transistors) are used. The first switch 36 is provided between the first receiving antenna 41 and the receiving circuit 34 . A second switch 37 is provided between the second receiving antenna 42 and the receiving circuit 34 . When the first switch 36 is on, the first receiving antenna 41 is connected to the receiving circuit 34 . When the second switch 37 is on, the second receiving antenna 42 is connected to the receiving circuit 34 . The receiver control device 31 selectively switches which of the first switch 36 and the second switch 37 is turned on. Therefore, when the first switch 36 is on, the second switch 37 is off. The first switch 36 is off when the second switch 37 is on. Thereby, the switching circuit 35 selectively switches the receiving antenna connected to the receiving circuit 34 among the plurality of receiving antennas 41 and 42 .
　受信回路３４は、受信アンテナ４１，４２が受信した無線信号を取得する。受信回路３４は、取得した無線信号を復調して、フレームに含まれるデータを得る。受信回路３４は、データを受信機用制御装置３１に出力する。これにより、受信機用制御装置３１は、センサ２２の測定結果を取得する。センサ２２の測定結果は、無線信号から得られた情報である。 The receiving circuit 34 acquires the radio signals received by the receiving antennas 41 and 42 . The receiving circuit 34 demodulates the acquired radio signal to obtain data contained in the frame. The receiving circuit 34 outputs data to the receiver control device 31 . Thereby, the receiver control device 31 acquires the measurement result of the sensor 22 . The measurement results of sensor 22 are information obtained from radio signals.
　通信装置３８は、通信制御部やポート等を備え、通信網ＮＷを通じて情報の送受信を行うことができるネットワーク機器である。通信装置３８は、通信網ＮＷを介してサーバー４０に接続されている。 The communication device 38 is a network device that includes a communication control unit, ports, etc., and is capable of transmitting and receiving information through the communication network NW. The communication device 38 is connected to the server 40 via the communication network NW.
　サーバー４０は、データベースＤＢ１を備える。サーバー４０は、複数台であってもよいし、１台であってもよい。データベースＤＢ１は、センサ２２の測定結果に関するデータの集合である。 The server 40 has a database DB1. The number of servers 40 may be plural or may be one. The database DB1 is a set of data regarding the measurement results of the sensor 22. FIG.
　図４に示すように、サーバー４０が作成するデータベースＤＢ１は、測定温度に、測定時刻、及び測定位置を対応付けたものである。測定時刻は、センサ２２が路面ＲＳ１の温度を測定した時刻である。測定位置は、各送信機２０が設けられた位置である。各送信機２０の位置は、例えば、地球上の絶対位置を表す座標系の座標で表現される。この種の座標系としては、例えば、地理座標系を挙げることができる。各送信機２０の位置は、無線信号に含まれるＩＤコードから特定されてもよい。これを実現するために、各送信機２０のＩＤコードに送信機２０の座標を対応付けた情報が、サーバー４０、あるいは、受信機３０に予め記憶される。この場合、受信機３０、又はサーバー４０が各送信機２０の位置を特定する。また、各送信機２０の位置を示す情報を含む無線信号を各送信機２０が送信するようにしてもよい。 As shown in FIG. 4, the database DB1 created by the server 40 associates the measured temperature with the measurement time and the measurement position. The measurement time is the time when the sensor 22 measures the temperature of the road surface RS1. A measurement position is a position where each transmitter 20 is provided. The position of each transmitter 20 is represented, for example, by coordinates in a coordinate system representing absolute positions on the earth. A coordinate system of this kind can be, for example, a geographic coordinate system. The location of each transmitter 20 may be specified from an ID code included in the radio signal. In order to realize this, information in which the ID code of each transmitter 20 is associated with the coordinates of the transmitter 20 is pre-stored in the server 40 or the receiver 30 . In this case, the receiver 30 or server 40 identifies the location of each transmitter 20 . Also, each transmitter 20 may transmit a radio signal including information indicating the position of each transmitter 20 .
　サーバー４０は、ユーザーに対してサービスを提供する。サービスは、クラウドとして提供される。クラウドは、データを蓄積したり、サービスを提供したりするコンピュータの利用形態の１つである。サービスとしては、例えば、データベースＤＢ１の提供を挙げることができる。また、サーバー４０は、データベースＤＢ１に基づいて導出された路面ＲＳ１に関する情報をユーザーに提供してもよい。データベースＤＢ１に基づいて導出された路面ＲＳ１に関する情報は、例えば、路面ＲＳ１の凍結情報を含む。路面ＲＳ１が凍結しているか否かは、測定温度と、測定位置から推定することができる。測定温度が０度以下の場合、当該測定温度に対応付けられた測定位置は凍結していると推定することができる。路面ＲＳ１が凍結しているか否かの推定は、サーバー４０、又はサーバー４０に接続された管理コンピュータによって行われる。そして、サーバー４０は、クラウドによって路面ＲＳ１に関する情報をユーザーに提供する。サーバー４０は、ユーザーに対してウェブブラウザ及びアプリケーションの少なくとも一方で、路面ＲＳ１に関する情報を提供する。路面ＲＳ１に関する情報は、テキストで提供されてもよいし、画像で提供されてもよい。これにより、測定温度が０度以下の場合、路面ＲＳ１が凍結している可能性があることをユーザーに対して注意喚起することができる。 The server 40 provides services to users. Services are provided as a cloud. A cloud is one form of computer usage that accumulates data and provides services. As a service, for example, provision of the database DB1 can be mentioned. The server 40 may also provide the user with information on the road surface RS1 derived based on the database DB1. The information on the road surface RS1 derived based on the database DB1 includes, for example, information on the freezing of the road surface RS1. Whether or not the road surface RS1 is frozen can be estimated from the measured temperature and the measured position. If the measured temperature is 0 degrees or less, it can be estimated that the measurement position associated with the measured temperature is frozen. The server 40 or a management computer connected to the server 40 estimates whether the road surface RS1 is frozen. The server 40 then provides the user with information on the road surface RS1 via the cloud. The server 40 provides information on the road surface RS1 to the user through at least one of a web browser and an application. Information about the road surface RS1 may be provided as text or as an image. Accordingly, when the measured temperature is 0 degrees or less, it is possible to alert the user that the road surface RS1 may be frozen.
　受信機用制御装置３１が行う切替処理について説明する。切替処理は、第１受信アンテナ４１及び第２受信アンテナ４２のうち、受信回路３４に接続する受信アンテナを切り替える処理である。切替処理は、所定の制御周期で繰り返し行われる。 The switching process performed by the receiver control device 31 will be explained. The switching process is a process of switching the receiving antenna connected to the receiving circuit 34 between the first receiving antenna 41 and the second receiving antenna 42 . The switching process is repeatedly performed at a predetermined control cycle.
　図５に示すように、ステップＳ１０において、受信機用制御装置３１は、所定時間が経過したか否かを判定する。所定時間は、前回に受信アンテナ４１，４２の切り替えを行ってからの経過時間である。ステップＳ１０の判定結果が否定の場合、受信機用制御装置３１は、切替処理を終える。所定時間は、無線信号の送信間隔よりも長い。ステップＳ１０の判定結果が肯定の場合、受信機用制御装置３１は、ステップＳ１１の処理を行う。 As shown in FIG. 5, in step S10, the receiver control device 31 determines whether or not a predetermined time has passed. The predetermined time is the elapsed time since the receiving antennas 41 and 42 were switched last time. If the determination result in step S10 is negative, the receiver control device 31 ends the switching process. The predetermined time is longer than the transmission interval of radio signals. If the determination result of step S10 is affirmative, the receiver control device 31 performs the process of step S11.
　ステップＳ１１において、受信機用制御装置３１は、受信アンテナ４１，４２の切り替えを行う。受信機用制御装置３１は、第１スイッチ３６がオンであれば、第１スイッチ３６をオフにし、第２スイッチ３７をオンする。受信機用制御装置３１は、第２スイッチ３７がオンであれば、第２スイッチ３７をオフにし、第１スイッチ３６をオンする。受信機用制御装置３１は、両スイッチ３６，３７のオンとオフとを切り替える際に、両スイッチ３６，３７がともにオフになるデッドタイムを設けてもよい。受信回路３４に接続される受信アンテナが、所定時間毎に、第１受信アンテナ４１と第２受信アンテナ４２との間で交互に切り替えられる。上記したように、受信機３０を用いて送信機２０から送信される無線信号を受信する受信方法では、受信機用制御装置３１が時間経過に応じて受信回路３４に接続される受信アンテナ４１，４２を切り替える。 In step S11, the receiver control device 31 switches between the receiving antennas 41 and 42. If the first switch 36 is on, the receiver control device 31 turns off the first switch 36 and turns on the second switch 37 . If the second switch 37 is on, the receiver control device 31 turns off the second switch 37 and turns on the first switch 36 . The receiver control device 31 may provide a dead time during which both the switches 36 and 37 are turned off when switching between on and off of the switches 36 and 37 . The receiving antenna connected to the receiving circuit 34 is alternately switched between the first receiving antenna 41 and the second receiving antenna 42 every predetermined time. As described above, in the receiving method of receiving the radio signal transmitted from the transmitter 20 using the receiver 30, the receiver control device 31 controls the receiving antenna 41, which is connected to the receiving circuit 34 as time elapses. Switch 42.
　本実施形態の作用について説明する。 The action of this embodiment will be described.
　図３に示すように、第１送信機群ＴＧ１のうち、構造物ＵＰ１から第１方向に離れている送信機２０を第１送信機２０Ａ、構造物ＵＰ１から第２方向に離れている送信機２０を第２送信機２０Ｂとする。第１送信機２０Ａは、構造物ＵＰ１に対して第１の側に配置されている。第２送信機２０Ｂは、構造物ＵＰ１に対して、第１の側とは反対の第２の側に配置されている。第１送信機２０Ａから送信される無線信号は第１受信アンテナ４１で受信されやすい。一方で、第２送信機２０Ｂから送信される無線信号は第１受信アンテナ４１で受信されにくい。これは、第２送信機２０Ｂと第１受信アンテナ４１との間にある構造物ＵＰ１によって無線信号が遮られるおそれがあるためである。同様に、第２送信機２０Ｂから送信される無線信号は第２受信アンテナ４２で受信されやすい。一方で、第１送信機２０Ａから送信される無線信号は第２受信アンテナ４２で受信されにくい。仮に、第１受信アンテナ４１のみで無線信号を受信する場合、第２送信機２０Ｂの無線信号を継続的に受信回路３４が取得できない事態が生じ得る。第２受信アンテナ４２のみで無線信号を受信する場合、第１送信機２０Ａの無線信号を継続的に受信回路３４が取得できない事態が生じ得る。 As shown in FIG. 3, among the first transmitter group TG1, the transmitter 20 that is away from the structure UP1 in the first direction is the first transmitter 20A, and the transmitter that is away from the structure UP1 in the second direction 20 is a second transmitter 20B. A first transmitter 20A is arranged on a first side with respect to the structure UP1. A second transmitter 20B is arranged on a second side opposite the first side with respect to the structure UP1. A radio signal transmitted from the first transmitter 20A is easily received by the first receiving antenna 41 . On the other hand, radio signals transmitted from the second transmitter 20B are difficult to be received by the first receiving antenna 41 . This is because the structure UP1 between the second transmitter 20B and the first receiving antenna 41 may block radio signals. Similarly, radio signals transmitted from the second transmitter 20B are likely to be received by the second receiving antenna 42 . On the other hand, it is difficult for the second receiving antenna 42 to receive the radio signal transmitted from the first transmitter 20A. If a radio signal is received only by the first receiving antenna 41, a situation may arise in which the receiving circuit 34 cannot continuously acquire the radio signal of the second transmitter 20B. When the radio signal is received only by the second receiving antenna 42, a situation may occur in which the receiving circuit 34 cannot continuously acquire the radio signal of the first transmitter 20A.
　本実施形態のように、互いに異なる位置に設けられる第１受信アンテナ４１及び第２受信アンテナ４２の少なくとも一方で無線信号を受信できれば、受信回路３４に無線信号を取得させることができる。これにより、受信機用制御装置３１は、センサ２２の測定結果を得ることができる。詳細にいえば、第１受信アンテナ４１が受信回路３４に接続されている場合には、第２送信機２０Ｂからの無線信号を受信しにくいため、受信回路３４が一部の送信機２０からの無線信号を取得できない場合がある。しかしながら、受信回路３４に接続される受信アンテナ４１，４２は時間経過によって切り替わるため、第２受信アンテナ４２が受信回路３４に接続されている場合には、第２送信機２０Ｂからの無線信号を受信しやすくなる。これにより、各送信機２０からの無線信号を継続的に受信できない事態が生じにくくなる。 As in the present embodiment, if at least one of the first receiving antenna 41 and the second receiving antenna 42 provided at different positions can receive a radio signal, the receiving circuit 34 can acquire the radio signal. Thereby, the receiver control device 31 can obtain the measurement result of the sensor 22 . Specifically, when the first receiving antenna 41 is connected to the receiving circuit 34, it is difficult to receive the radio signal from the second transmitter 20B. Wireless signal may not be acquired. However, since the receiving antennas 41 and 42 connected to the receiving circuit 34 are switched over time, when the second receiving antenna 42 is connected to the receiving circuit 34, the radio signal from the second transmitter 20B is received. easier to do. This makes it less likely that the radio signal from each transmitter 20 cannot be received continuously.
　図６に示すように、第１受信アンテナ４１による受信期間Ｒ１１と、第２受信アンテナ４２による受信期間Ｒ２１とは、所定時間Ｔ１で切り替わる。所定時間Ｔ１は、無線信号の送信間隔Ｔ２よりも長いため、１つの受信期間Ｒ１１，Ｒ２１の間に、各送信機２０は少なくとも１回は無線信号を送信する。第１受信アンテナ４１の受信期間Ｒ１１には、第１送信機２０Ａからの無線信号Ｓｅ１を受信しやすい。第２受信アンテナ４２の受信期間Ｒ２１には第２送信機２０Ｂからの無線信号Ｓｅ２を受信しやすい。このため、各送信機２０からの無線信号Ｓｅ１，Ｓｅ２を継続して受信できない事態が生じにくい。 As shown in FIG. 6, the reception period R11 by the first reception antenna 41 and the reception period R21 by the second reception antenna 42 are switched at a predetermined time T1. Since the predetermined time T1 is longer than the radio signal transmission interval T2, each transmitter 20 transmits a radio signal at least once during one reception period R11, R21. During the reception period R11 of the first reception antenna 41, it is easy to receive the radio signal Se1 from the first transmitter 20A. During the reception period R21 of the second reception antenna 42, the radio signal Se2 from the second transmitter 20B is likely to be received. Therefore, it is unlikely that the radio signals Se1 and Se2 from the transmitters 20 cannot be received continuously.
　本実施形態の効果について説明する。 The effect of this embodiment will be explained.
　（１）受信機３０は、複数の受信アンテナ４１，４２を備える。複数の受信アンテナ４１，４２の少なくとも１つで無線信号を受信することで、受信回路３４に無線信号を取得させることができる。このため、送信機２０から送信された無線信号を受信機３０が受信しやすい。特に、複数の送信機２０から送信された無線信号を受信する受信機３０の場合、受信アンテナを１つのみとすると、全ての送信機２０の無線信号を受信できるように受信アンテナの位置を定めるのは困難である。これに対し、複数の受信アンテナ４１，４２を設けることで、複数の受信アンテナ４１，４２の少なくとも１つで無線信号を受信できればよく、受信機３０の数を増加させることなく、複数の送信機２０からの無線信号を受信できる。 (1) The receiver 30 includes a plurality of receiving antennas 41 and 42. By receiving a radio signal with at least one of the plurality of receiving antennas 41 and 42, the receiving circuit 34 can acquire the radio signal. Therefore, the receiver 30 can easily receive the radio signal transmitted from the transmitter 20 . In particular, in the case of a receiver 30 that receives radio signals transmitted from a plurality of transmitters 20, if there is only one reception antenna, the position of the reception antenna is determined so that radio signals from all transmitters 20 can be received. is difficult. On the other hand, by providing a plurality of receiving antennas 41 and 42, it is sufficient that at least one of the plurality of receiving antennas 41 and 42 can receive a radio signal, and a plurality of transmitters can be used without increasing the number of receivers 30. 20 can receive radio signals.
　（２）時間経過に応じて、複数の受信アンテナ４１，４２のうち受信回路３４に接続される受信アンテナを切り替えている。結合器で結合された複数の受信アンテナ４１，４２によって無線信号の受信を行う場合には、結合器が無線信号の受信電圧を低下させ得る。本実施形態では、結合器に起因する受信電圧の低下を回避できる。 (2) The receiving antenna connected to the receiving circuit 34 is switched among the plurality of receiving antennas 41 and 42 according to the passage of time. When radio signals are received by a plurality of receiving antennas 41 and 42 that are combined by a combiner, the combiner can reduce the received voltage of the radio signal. In this embodiment, it is possible to avoid a drop in the received voltage caused by the coupler.
　（３）複数の受信アンテナ４１，４２を用いて無線信号を受信する方式にダイバーシティ方式がある。ダイバーシティ方式では、複数の受信アンテナ４１，４２のうち、受信レベルの高い方の受信アンテナを受信回路３４に接続する。従って、ダイバーシティ方式を用いて無線信号を受信しようとすると、受信アンテナ４１，４２の受信レベルを検出する必要がある。受信レベルを検出するためには、無線信号の送信時間を長くする必要がある。従って、ダイバーシティ方式を用いる場合、無線信号の送信時間を長くする必要があり、送信機２０のバッテリ２１の寿命が短くなるおそれがある。これに対し、本実施形態では、時間経過に応じて受信アンテナ４１，４２を切り替えているだけである。よって、受信アンテナ４１，４２の受信レベルを検出する必要はなく、また受信レベルを検出するために無線信号の送信時間を長くするという必要もない。従って、バッテリ２１の長寿命化が図られる。 (3) There is a diversity method for receiving radio signals using a plurality of receiving antennas 41 and 42 . In the diversity system, the receiving antenna having the higher reception level among the plurality of receiving antennas 41 and 42 is connected to the receiving circuit 34 . Therefore, when trying to receive radio signals using the diversity system, it is necessary to detect the reception levels of the reception antennas 41 and 42 . In order to detect the reception level, it is necessary to lengthen the transmission time of the radio signal. Therefore, when using the diversity method, it is necessary to lengthen the transmission time of the radio signal, and there is a possibility that the life of the battery 21 of the transmitter 20 will be shortened. On the other hand, in this embodiment, the receiving antennas 41 and 42 are simply switched according to the passage of time. Therefore, it is not necessary to detect the reception levels of the receiving antennas 41 and 42, and it is not necessary to lengthen the transmission time of the radio signal in order to detect the reception levels. Therefore, the service life of the battery 21 can be extended.
　（４）受信機用制御装置３１は、無線信号の送信間隔よりも長い間隔で受信回路３４に接続する受信アンテナを切り替える。無線信号の送信間隔よりも短い間隔で受信アンテナ４１，４２の切り替えを行う場合、無線信号の受信中に受信アンテナ４１，４２の切り替えが行われてしまうおそれがある。これに対し、無線信号の送信間隔よりも長い間隔で受信アンテナ４１，４２の切り替えを行うことで、無線信号の受信中に受信アンテナ４１と，４２の切り替えが行われることを抑制できる。 (4) The receiver control device 31 switches the receiving antenna connected to the receiving circuit 34 at intervals longer than the radio signal transmission interval. If the reception antennas 41 and 42 are switched at an interval shorter than the radio signal transmission interval, there is a possibility that the reception antennas 41 and 42 are switched during reception of the radio signal. On the other hand, by switching the reception antennas 41 and 42 at intervals longer than the transmission interval of the radio signal, it is possible to suppress the switching between the reception antennas 41 and 42 during reception of the radio signal.
　（５）受信機３０は、通信装置３８を備える。通信装置３８を介して、センサ２２の測定結果をサーバー４０に送信することができる。これにより、測定結果をサーバー４０に蓄積することができる。 (5) The receiver 30 includes a communication device 38 . Via communication device 38 , the measurements of sensor 22 can be transmitted to server 40 . Thereby, the measurement results can be stored in the server 40 .
　（６）センサ２２の測定結果は、送信機２０から受信機３０に送信され、更に受信機３０からサーバー４０に送信される。複数の送信機２０の測定結果を受信機３０が受信し、受信機３０がサーバー４０に測定結果を送信することで、受信機３０にのみ通信装置３８を設ければよい。このため、送信機２０毎に通信装置３８を設ける場合に比べて、送信機２０の製造コストを低減することができる。また、送信機２０毎に通信装置３８を設ける場合に比べて、サーバー４０との通信による通信コストを低減することができる。 (6) The measurement result of the sensor 22 is transmitted from the transmitter 20 to the receiver 30, and further transmitted from the receiver 30 to the server 40. The receiver 30 receives the measurement results of a plurality of transmitters 20, and the receiver 30 transmits the measurement results to the server 40, so that only the receiver 30 needs to be provided with the communication device 38. FIG. Therefore, the manufacturing cost of the transmitters 20 can be reduced compared to the case where the communication device 38 is provided for each transmitter 20 . Also, the communication cost for communication with the server 40 can be reduced compared to the case where the communication device 38 is provided for each transmitter 20 .
　実施形態は、以下のように変更して実施することができる。各実施形態及び以下の変形例は、技術的に矛盾しない範囲で互いに組み合わせて実施することができる。 The embodiment can be changed and implemented as follows. Each embodiment and the following modifications can be implemented in combination with each other within a technically consistent range.
　・受信アンテナは、３つ以上であってもよい。この場合、時間経過に応じて受信回路３４に接続される受信アンテナが順番に切り替わるようにしてもよい。時間経過に応じて受信回路３４に接続される受信アンテナがランダムに切り替わるようにしてもよい。 · There may be three or more receiving antennas. In this case, the receiving antenna connected to the receiving circuit 34 may be switched in order as time elapses. The receiving antenna connected to the receiving circuit 34 may be randomly switched over time.
　・受信回路３４に接続される受信アンテナ４１，４２を切り替える間隔は、無線信号の送信間隔より短くてもよい。 · The interval at which the receiving antennas 41 and 42 connected to the receiving circuit 34 are switched may be shorter than the interval at which the radio signals are transmitted.
　・受信回路３４に接続される受信アンテナ４１，４２を切り替える間隔は、ランダムでもよい。この場合であっても、受信回路３４に接続される受信アンテナ４１，４２を切り替える間隔は無線信号の送信間隔より長くしてもよい。 · The interval at which the receiving antennas 41 and 42 connected to the receiving circuit 34 are switched may be random. Even in this case, the interval at which the receiving antennas 41 and 42 connected to the receiving circuit 34 are switched may be longer than the radio signal transmission interval.
　・切替回路３５としては、オペアンプ、バッファ、メカニカルリレー、又はMEMS(Micro Electro Mechanical Systems)リレーを用いたものであってもよい。 · The switching circuit 35 may use an operational amplifier, a buffer, a mechanical relay, or a MEMS (Micro Electro Mechanical Systems) relay.
　・図７に示すように、第１受信アンテナ４１と第２受信アンテナ４２とは、２つの車線Ｌ１，Ｌ２の向かい合う方向に互いに離れて設けられていてもよい。図７に示す例では、第２送信機群ＴＧ２の送信機２０から第２受信アンテナ４２までの距離は、第２送信機群ＴＧ２の送信機２０から第１受信アンテナ４１までの距離よりも短い。第２受信アンテナ４２によって第２送信機群ＴＧ２の送信機２０から送信される無線信号を受信しやすくなる。 · As shown in FIG. 7, the first receiving antenna 41 and the second receiving antenna 42 may be provided apart from each other in the facing directions of the two lanes L1 and L2. In the example shown in FIG. 7, the distance from the transmitter 20 of the second transmitter group TG2 to the second receiving antenna 42 is shorter than the distance from the transmitter 20 of the second transmitter group TG2 to the first receiving antenna 41. . The second receiving antenna 42 facilitates reception of radio signals transmitted from the transmitters 20 of the second transmitter group TG2.
　図７では、第２受信アンテナ４２を第１受信アンテナ４１よりも高い位置に設けている。第２受信アンテナ４２を低い位置に設けると、車両Ｖ１が障害物となることによって第２受信アンテナ４２による無線信号の受信が阻害されるおそれがある。第２受信アンテナ４２を車両Ｖ１の最上部が到達すると想定される高さよりも高い位置に設けることで、車両Ｖ１によって無線信号の受信が阻害されることを抑制できる。 In FIG. 7, the second receiving antenna 42 is provided at a higher position than the first receiving antenna 41. If the second receiving antenna 42 is provided at a low position, there is a risk that the reception of the radio signal by the second receiving antenna 42 will be hindered by the vehicle V1 becoming an obstacle. By providing the second receiving antenna 42 at a position higher than the height assumed to be reached by the top of the vehicle V1, it is possible to prevent the vehicle V1 from obstructing the reception of the radio signal.
　・図８に示すように、第１受信アンテナ４１と第２受信アンテナ４２の向きとを異ならせてもよい。言い換えれば、第１受信アンテナ４１の偏波面と第２受信アンテナ４２の偏波面とを異ならせてもよい。 · As shown in FIG. 8, the directions of the first receiving antenna 41 and the second receiving antenna 42 may be different. In other words, the plane of polarization of the first receiving antenna 41 and the plane of polarization of the second receiving antenna 42 may be different.
　・第１受信アンテナ４１と第２受信アンテナ４２の種類を異ならせてもよい。例えば、第１受信アンテナ４１をループアンテナとし、第２受信アンテナ４２をヘリカルアンテナとしてもよい。アンテナの種類が異なると、偏波面や指向性が異なる。これにより、第１受信アンテナ４１と第２受信アンテナ４２とを同様の位置に設けたとしても、第１受信アンテナ４１と第２受信アンテナ４２とで、無線信号を受信しやすい送信機２０が異なる。従って、第１受信アンテナ４１と第２受信アンテナ４２との配置の自由度を高めることができる。 · The types of the first receiving antenna 41 and the second receiving antenna 42 may be different. For example, the first receiving antenna 41 may be a loop antenna and the second receiving antenna 42 may be a helical antenna. Different types of antennas have different planes of polarization and directivities. As a result, even if the first receiving antenna 41 and the second receiving antenna 42 are provided at the same position, the transmitters 20 that are likely to receive radio signals are different between the first receiving antenna 41 and the second receiving antenna 42. . Therefore, the degree of freedom of arrangement of the first receiving antenna 41 and the second receiving antenna 42 can be increased.
　・送信機２０は、舗装されていない地面に設けられていてもよい。 · The transmitter 20 may be provided on unpaved ground.
　・送信機２０は、センサ２２として圧力センサを備えていてもよい。この場合、圧力センサは、大気圧を測定するように設けられる。圧力センサの測定結果は、サーバー４０に送信されてもよい。圧力センサの測定結果は、例えば、気象予報に用いることができる。 · The transmitter 20 may include a pressure sensor as the sensor 22 . In this case, a pressure sensor is provided to measure the atmospheric pressure. The pressure sensor measurement results may be transmitted to the server 40 . The measurement results of the pressure sensor can be used, for example, for weather forecasting.
　・送信機２０は、センサ２２として加速度センサを備えていてもよい。加速度センサは、加速度センサに加わる加速度を測定する。車両Ｖ１が送信機２０の上を通過した場合には、送信機２０に衝撃が加わる。これにより、車両Ｖ１が送信機２０の上を通過していない場合に比べて、加速度センサに大きな加速度が加わる。従って、事故が発生した場合に、事故が発生した時刻での加速度センサの測定結果を確認することで、車両Ｖ１が通過した経路の把握に役立てることができる。 · The transmitter 20 may include an acceleration sensor as the sensor 22 . The acceleration sensor measures acceleration applied to the acceleration sensor. When the vehicle V1 passes over the transmitter 20, the transmitter 20 is impacted. As a result, a larger acceleration is applied to the acceleration sensor than when the vehicle V1 does not pass over the transmitter 20 . Therefore, when an accident occurs, checking the measurement result of the acceleration sensor at the time when the accident occurred can be useful for grasping the route that the vehicle V1 has passed.
　・送信機２０は、どのような場所に設けられていてもよい。実施形態のように、センサ２２として温度センサを用いている場合、温度を測定したい対象に送信機２０を設ければよい。例えば、信号機の上に送信機２０を設けてもよい。この場合、温度センサの測定結果から、信号機の上に雪が積もっているか否かの判定を行うことができる。センサ２２として加速度センサを用いる場合、傾きを検出したい対象に送信機２０を設けてもよい。例えば、重力加速度を検出するように加速度センサを設ける。加速度センサが傾くと、加速度センサによって検出される加速度が変化する。このため、傾きを検出したい対象に送信機２０を設けると、対象が傾いたことを受信機３０で検出することができる。例えば、信号機の上に送信機２０を設けて、信号機に傾きが生じたか否かを受信機３０で判定できるようにしてもよい。 · The transmitter 20 may be provided at any location. When a temperature sensor is used as the sensor 22 as in the embodiment, the transmitter 20 may be provided for the target whose temperature is to be measured. For example, a transmitter 20 may be provided above the traffic light. In this case, it is possible to determine whether or not snow is piled up on the traffic signal from the measurement result of the temperature sensor. When an acceleration sensor is used as the sensor 22, the transmitter 20 may be provided on the target whose tilt is to be detected. For example, an acceleration sensor is provided to detect gravitational acceleration. When the acceleration sensor tilts, the acceleration detected by the acceleration sensor changes. For this reason, if the transmitter 20 is provided for the target whose tilt is to be detected, the tilt of the target can be detected by the receiver 30 . For example, the transmitter 20 may be provided above the traffic light so that the receiver 30 can determine whether the traffic light has tilted.
　・通信システム１０は、サーバー４０を備えていなくてもよい。この場合、受信機３０は、複数の送信機２０から送信された測定結果を受信して、当該測定結果を記憶するように構成されてもよい。また、通信システム１０は、表示部及び発光部の少なくとも一方を備えていてもよい。表示部及び発光部の少なくとも一方は、受信機３０が備えていてもよいし、受信機３０とは別体として設けられていてもよい。受信機用制御装置３１は、センサ２２の測定結果から路面ＲＳ１の状態を推定し、路面ＲＳ１の状態に応じて表示部及び発光部の少なくとも一方の制御を行ってもよい。センサ２２が温度センサであれば、受信機用制御装置３１は、路面ＲＳ１が凍結しているか否かを推定してもよい。例えば、受信機用制御装置３１は、センサ２２の測定結果が０度以下の場合には、路面ＲＳ１が凍結していると推定してもよい。そして、受信機用制御装置３１は、路面ＲＳ１が凍結していると推定した場合には、表示部への表示や発光部の発光を行う。これにより、受信機３０の周囲の人に対して、注意喚起を行うことができる。 · The communication system 10 may not include the server 40 . In this case, the receiver 30 may be configured to receive measurement results transmitted from multiple transmitters 20 and store the measurement results. Further, the communication system 10 may include at least one of a display section and a light emitting section. At least one of the display unit and the light emitting unit may be included in the receiver 30 or may be provided separately from the receiver 30 . The receiver control device 31 may estimate the state of the road surface RS1 from the measurement result of the sensor 22, and control at least one of the display unit and the light emitting unit according to the state of the road surface RS1. If the sensor 22 is a temperature sensor, the receiver controller 31 may estimate whether the road surface RS1 is frozen. For example, the receiver control device 31 may estimate that the road surface RS1 is frozen when the measurement result of the sensor 22 is 0 degrees or less. Then, when the receiver control device 31 estimates that the road surface RS1 is frozen, it performs display on the display unit and light emission from the light emitting unit. As a result, the attention of people around the receiver 30 can be called.
　・送信機２０は、１つのみであってもよい。この場合であっても、車両Ｖ１などの障害物の影響によって、いずれかの受信アンテナ４１，４２が無線信号を受信しにくくなっても、もう一方の受信アンテナ４１，４２で無線信号を受信することができる。従って、車両Ｖ１などの障害物の影響を低減できる。 · There may be only one transmitter 20 . Even in this case, even if one of the receiving antennas 41 and 42 becomes difficult to receive the radio signal due to the influence of an obstacle such as the vehicle V1, the other receiving antenna 41 or 42 receives the radio signal. be able to. Therefore, the influence of obstacles such as the vehicle V1 can be reduced.
　ＤＢ１…データベース、１０…通信システム、２０…送信機、２３…送信機用制御装置、２６…送信回路、３０…受信機、３１…受信機用制御装置、３４…受信回路、３５…切替回路、３８…通信装置、４０…サーバー、４１，４２…受信アンテナ。 DB1...Database, 10...Communication system, 20...Transmitter, 23...Transmitter control device, 26...Transmitting circuit, 30...Receiver, 31...Receiver control device, 34...Receiving circuit, 35...Switching circuit, 38... Communication device, 40... Server, 41, 42... Receiving antenna.

Claims (7)

  1. 　送信機との相対的位置関係が一定となるように配置される受信機であって、
    　前記送信機から所定の送信間隔で送信される無線信号を受信するように構成された複数の受信アンテナと、
    　前記複数の受信アンテナを介して前記無線信号を取得するように構成された受信回路と、
    　前記複数の受信アンテナのうち前記受信回路に接続する受信アンテナを選択的に切り替えるように構成された切替回路と、
    　前記切替回路を制御するように構成された受信機用制御装置と、を備え、
    　前記受信機用制御装置は、時間経過に応じて前記受信回路に接続する前記受信アンテナを切り替えるように構成されている、受信機。     A receiver arranged so that the relative positional relationship with the transmitter is constant,
    a plurality of receiving antennas configured to receive radio signals transmitted from the transmitter at predetermined transmission intervals;
    a receiving circuit configured to acquire the radio signal via the plurality of receiving antennas;
    a switching circuit configured to selectively switch a receiving antenna connected to the receiving circuit among the plurality of receiving antennas;
    a receiver controller configured to control the switching circuit;
    The receiver, wherein the receiver control device is configured to switch the receiving antenna connected to the receiving circuit according to the passage of time.
  2. 　前記受信機用制御装置は、前記送信間隔よりも長い間隔で前記受信回路に接続する前記受信アンテナを切り替えるように構成されている、請求項１に記載の受信機。 The receiver according to claim 1, wherein said receiver control device is configured to switch said receiving antenna connected to said receiving circuit at an interval longer than said transmission interval.
  3. 　前記無線信号から得られた情報をサーバーに送信する通信装置をさらに備え、
    　前記サーバーは、前記情報に関するデータベースを備える、請求項１又は請求項２に記載の受信機。     further comprising a communication device that transmits information obtained from the wireless signal to a server;
    3. A receiver according to claim 1 or claim 2, wherein said server comprises a database for said information.
  4. 　送信機と、
    　前記送信機との相対的位置関係が一定となるように配置される受信機と、を備えた通信システムであって、
    　前記送信機は、
    　　無線信号を送信するように構成された送信回路と、
    　　前記無線信号を所定の送信間隔で前記送信回路から送信させるように構成された送信機用制御装置と、を備え、
    　前記受信機は、
    　　前記無線信号を受信するように構成された複数の受信アンテナと、
    　　前記複数の受信アンテナを介して前記無線信号を取得するように構成された受信回路と、
    　　前記複数の受信アンテナのうち前記受信回路に接続する受信アンテナを選択的に切り替えるように構成された切替回路と、
    　　前記切替回路を制御するように構成された受信機用制御装置と、を備え、
    　前記受信機用制御装置は、時間経過に応じて前記受信回路に接続する前記受信アンテナを切り替えるように構成されている、通信システム。     a transmitter;
    A communication system comprising a receiver arranged so that the relative positional relationship with the transmitter is constant,
    The transmitter is
    a transmitter circuit configured to transmit a radio signal;
    a transmitter control device configured to transmit the radio signal from the transmission circuit at a predetermined transmission interval;
    The receiver is
    a plurality of receive antennas configured to receive the radio signal;
    a receiving circuit configured to acquire the radio signal via the plurality of receiving antennas;
    a switching circuit configured to selectively switch a receiving antenna connected to the receiving circuit among the plurality of receiving antennas;
    a receiver controller configured to control the switching circuit;
    The communication system, wherein the receiver control device is configured to switch the receiving antenna connected to the receiving circuit according to the passage of time.
  5. 　前記受信機は地面に設置された構造物に取り付けられ、
    　前記複数の受信アンテナは、
    　　前記構造物に対して第１の側に配置される第１受信アンテナと、
    　　前記構造物に対して、第１の側とは反対の第２の側に配置される第２受信アンテナと、を含み、
    　前記送信機は、
    　　前記構造物に対して前記第１の側に配置される第１送信機と、
    　　前記構造物に対して前記第２の側に配置される第２送信機と、を含む、請求項４に記載の通信システム。     The receiver is attached to a structure placed on the ground,
    The plurality of receiving antennas,
    a first receiving antenna positioned on a first side with respect to the structure;
    a second receive antenna positioned on a second side opposite the first side with respect to the structure;
    The transmitter is
    a first transmitter positioned on the first side with respect to the structure;
    and a second transmitter located on said second side with respect to said structure.
  6. 　前記通信システムはさらに、サーバーを備え、
    　前記受信機は、前記無線信号から得られた情報を前記サーバーに送信するように構成された通信装置を備え、
    　前記サーバーは、前記情報に関するデータベースを備える、請求項４又は請求項５に記載の通信システム。     The communication system further comprises a server,
    the receiver comprises a communication device configured to transmit information obtained from the wireless signal to the server;
    6. A communication system according to claim 4 or 5, wherein said server comprises a database relating to said information.
  7. 　送信機との相対的位置関係が一定となるように受信機を配置することと、
    　前記送信機から所定の送信間隔で送信される無線信号を受信する複数の受信アンテナを前記受信機に設けることと、
    　前記複数の受信アンテナを介して前記無線信号を取得する受信回路を前記受信機に設けることと、
    　前記複数の受信アンテナのうち前記受信回路に接続する受信アンテナを時間経過に応じて選択的に切り替えることと、を備える受信方法。     Arranging the receiver so that the relative positional relationship with the transmitter is constant;
    providing the receiver with a plurality of receiving antennas for receiving radio signals transmitted from the transmitter at predetermined transmission intervals;
    providing the receiver with a receiving circuit that acquires the radio signal via the plurality of receiving antennas;
    A receiving method comprising selectively switching a receiving antenna connected to the receiving circuit among the plurality of receiving antennas according to the passage of time.
PCT/JP2021/024327 2021-06-28 2021-06-28 Receiver, communication system, and reception method WO2023275923A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/JP2021/024327 WO2023275923A1 (en) 2021-06-28 2021-06-28 Receiver, communication system, and reception method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/JP2021/024327 WO2023275923A1 (en) 2021-06-28 2021-06-28 Receiver, communication system, and reception method

Publications (1)

Publication Number Publication Date
WO2023275923A1 true WO2023275923A1 (en) 2023-01-05

Family

ID=84690986

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2021/024327 WO2023275923A1 (en) 2021-06-28 2021-06-28 Receiver, communication system, and reception method

Country Status (1)

Country Link
WO (1) WO2023275923A1 (en)

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6313536A (en) * 1986-07-04 1988-01-20 Matsushita Electric Works Ltd Transmission/reception system
JP2003087868A (en) * 2001-09-14 2003-03-20 Toa Corp Wireless communication system
US20120302191A1 (en) * 2011-05-24 2012-11-29 Continental Automotive Systems Us, Inc. Receiver with antenna switching capability

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6313536A (en) * 1986-07-04 1988-01-20 Matsushita Electric Works Ltd Transmission/reception system
JP2003087868A (en) * 2001-09-14 2003-03-20 Toa Corp Wireless communication system
US20120302191A1 (en) * 2011-05-24 2012-11-29 Continental Automotive Systems Us, Inc. Receiver with antenna switching capability

Similar Documents

Publication Publication Date Title
Lee et al. RFID assisted vehicle positioning in VANETs
US8884821B2 (en) Apparatus and method for determining vehicle location
US8401713B2 (en) Determining relative spatial information between vehicles
US20070100537A1 (en) System for and method of updating traffic data using probe vehicles having exterior sensors
US20080065311A1 (en) System and method for exchanging positioning information between vehicles in order to estimate road traffic
US20110248867A1 (en) Method and apparatus for providing traffic information service using a mobile communication system
EP2096456B1 (en) Method and apparatus for determining whether a moving entity is moving in a predetermined direction
WO2019013948A1 (en) Method for power adaptation of the environment perception system
KR20080049082A (en) An intelligent transportation system and method
US20130044612A1 (en) Autonomous wi-fi based ranging device
JP2015229433A (en) Road surface condition detection device and road surface condition detection system
Lee et al. RF-GPS: RFID assisted localization in VANETs
Artail et al. Avoiding car-pedestrian collisions using a VANET to cellular communication framework
WO2023275923A1 (en) Receiver, communication system, and reception method
US8035561B2 (en) Communication apparatus
JP5570767B2 (en) Non-power measuring device and non-power measuring system
US11946759B2 (en) Electronic device, wireless communication method and computer-readable storage medium
Ma et al. Analysis of directional antenna for railroad crossing safety applications
JP5477350B2 (en) Wireless communication apparatus and wireless communication method
WO2023275924A1 (en) Temperature measurement device and temperature measurement system
JP4974426B2 (en) Information communication equipment
JP2011248598A (en) Intersection monitoring system and mobile terminal device
JP2011085524A (en) Position detection system
KR101202639B1 (en) Apparatus having function of notifying traffic information and operating method thereof
KR20160012745A (en) Traffic informatin collecting system using tpms sensor and method thereof

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 21948237

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE