Roadside Relay Device, Traffic Management System, and Log Collection Method

Abstract

A device according to an embodiment of the present disclosure comprises: a first communication unit for communication with a management device; a second communication unit for communication with an information source device; a third communication unit for communication with a vehicle; and a communication control unit that extracts provision information for the vehicle from a reception frame of the second communication unit and outputs a transmission frame including the extracted provision information to the third communication unit, wherein the communication control unit determines the outcome of a condition related to the availability of the provision information on the basis of vehicle information included in a reception frame of the third communication unit and, if the condition is enacted, performs log collection of the provision information.

Description

Technical Field

[0001] The present disclosure relates to a roadside relay device, a traffic management system, and a log collection method. This application claims priority based on Japanese Application No. 2021-056626 filed on March 30, 2021, and incorporates by reference all the descriptions contained in the said Japanese application.

Background Art

[0002] Patent Document 1 describes a wireless communication system in which a roadside radio connected to a central device and a traffic signal controller belonging to a traffic control system receives signal information of an inflow road of an intersection from the traffic signal controller and provides the received signal information to a vehicle by vehicle-to-roadside communication. Patent Document 2 describes a traffic control system including a central device installed in a traffic control center, one or more line concentration devices (relay devices), and one or more terminal devices (traffic signal controllers, optical beacons, vehicle sensors, and traffic information boards).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

[0004] An apparatus according to an aspect of the present disclosure includes a first communication unit for communication with a management device, a second communication unit for communication with an information source device, a third communication unit for communication with a vehicle, and a communication control unit that extracts vehicle-provided information from a received frame of the second communication unit and outputs a transmission frame including the extracted provided information to the third communication unit. The communication control unit determines whether a condition leading to the availability of the provided information is satisfied based on vehicle information included in a received frame of the third communication unit, and when the condition is satisfied, executes log collection of the provided information.

[0005] A system according to one aspect of the present disclosure is a traffic management system including a management device, a roadside relay device that communicates with the management device, and an information source device that communicates with the management device via the roadside relay device. The roadside relay device performs relay processing for wirelessly transmitting vehicle-provided information received from the information source device to a vehicle, determines whether a condition leading to the availability of the provided information is satisfied based on vehicle information received from the vehicle, and performs log collection of the provided information when execution is permitted if the condition is satisfied.

[0006] A method according to one aspect of the present disclosure is a log collection method executed in a traffic management system including a management device, a roadside relay device that communicates with the management device, and an information source device that communicates with the management device via the roadside relay device. The roadside relay device includes a step of wirelessly transmitting vehicle-provided information received from the information source device to a vehicle, a step of determining whether a condition leading to the availability of the provided information is satisfied based on vehicle information received from the vehicle, and a step of performing log collection of the provided information when the condition is satisfied. Relay The device includes a step of determining whether a condition leading to the availability of the provided information is satisfied based on vehicle information received from the vehicle, and Relay The device includes a step of performing log collection of the provided information when the condition is satisfied.

[0007] The present disclosure can be realized not only as a system and device having the above-described characteristic configuration, but also as a program for causing a computer to execute such a characteristic configuration. Further, the present disclosure can be realized as a semiconductor integrated circuit that realizes part or all of the system and device.

Brief Description of Drawings

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DETAILED DESCRIPTION OF THE INVENTION

[0009] <PROBLEMS TO BE SOLVED BY THE PRESENT DISCLOSURE> If signal information provided for vehicles is collected as a log and managed by a central device, it becomes possible to determine whether the cause of a traffic accident is on the infrastructure side or the vehicle side. Therefore, it is preferable that the roadside radio also transmits signal information, which is information provided for vehicles, to the central device. However, signal information is a type of dynamic information that requires low latency. In a method of simply transmitting such dynamic information to the central device 1, it is necessary to adopt a broadband line and a storage device with a huge data capacity, resulting in high line costs and equipment costs.

[0010] The present disclosure aims to enable logging of information provided for vehicles while suppressing communication and equipment costs.

[0011] <Effect of the present disclosure> According to the present disclosure, it is possible to collect logs of information provided for vehicles while suppressing communication and equipment costs.

[0012] <Outline of embodiments of the present disclosure> The outline of the embodiments of the present disclosure will be listed and described below. (1) The apparatus according to the present embodiment includes a first communication unit for communicating with a management device, a second communication unit for communicating with an information source device, a third communication unit for communicating with a vehicle, and a communication control unit that extracts information provided for the vehicle from the received frame of the second communication unit and outputs a transmission frame including the extracted information provided for the vehicle to the third communication unit. The communication control unit determines whether a condition leading to the availability of the information provided for the vehicle is satisfied based on the vehicle information included in the received frame of the third communication unit, and when the condition is satisfied, executes logging of the information provided for the vehicle Roadside relay device.

[0013] According to the roadside relay device of the present embodiment, since the communication control unit executes logging of the information provided for the vehicle when the condition leading to the availability of the information provided for the vehicle is satisfied, information provided for the vehicle that has no possibility of being used by the vehicle is excluded from the collection target. Therefore, according to the roadside relay device of the present embodiment, it is possible to collect logs of information provided for vehicles while suppressing communication and equipment costs.

[0014] (2) In the roadside relay device of the present embodiment, it is preferable that the condition includes at least one of the following first condition and second condition. First condition: The vehicle is present within the service target area of the information provided for the vehicle Second condition: A condition different from the first condition leading to the availability of the information provided for the vehicle

[0015] The reason for including the above-mentioned first condition is that vehicles outside the service target area cannot appropriately utilize the received provided information even if they receive it. Therefore, the presence of a vehicle within the area can be regarded as one of the conditions related to the availability of the provided information. The reason for including the above-mentioned second condition is that even when the first condition is satisfied, there may be cases where the availability of the provided information is clearly absent, such as when the vehicle rejects the service based on the provided information. Therefore, it is effective to consider the second condition from a different perspective from the first condition.

[0016] (3) In the roadside Relay device of this embodiment, when the vehicle information includes the traveling position of the vehicle, the communication control unit may determine whether the first condition is met based on whether the traveling position is within the service target area. The reason is that since the traveling position included in the vehicle information almost accurately represents the current position of the vehicle, it is considered that it can be used for determining whether the first condition is met without any problems.

[0017] (4) In the roadside relay device of this embodiment, when the vehicle information includes the vehicle type of the vehicle, it is preferable to include in the second condition that the vehicle type matches the service target vehicle type on the infrastructure side. The reason is that when the vehicle type included in the vehicle information matches the service target vehicle type on the infrastructure side, the vehicle is highly likely to utilize the provided information for the vehicle.

[0018] (5) In the roadside relay device of this embodiment, when the vehicle information includes the service type being used by the vehicle, it is preferable to include in the second condition that the service type matches the service type on the infrastructure side. The reason is that when the service type included in the vehicle information matches the service type on the infrastructure side, the vehicle is highly likely to utilize the provided information for the vehicle.

[0019] (6) In the roadside relay device of the present embodiment, when the vehicle information includes a service setting state indicating permission or rejection of service use, it is preferable to include in the second condition that the service setting state is permission. The reason is that when the service setting state included in the vehicle information is permission, there is a high possibility that the vehicle will use the provided information for the vehicle.

[0020] (7) In the roadside relay device of the present embodiment, when the vehicle information includes the traveling direction of the vehicle, it is preferable to include in the second condition that the traveling direction matches the service target direction on the infrastructure side. The reason is that when the traveling direction included in the vehicle information matches the service target direction on the infrastructure side, there is a high possibility that the vehicle will use the provided information for the vehicle.

[0021] (8) In the roadside relay device of the present embodiment, when the vehicle information includes the planned route of the vehicle, it is preferable to include in the second condition that the planned route matches the service target route on the infrastructure side. The reason is that when the planned route included in the vehicle information matches the service target route on the infrastructure side, there is a high possibility that the vehicle will use the provided information for the vehicle.

[0022] (9) In the roadside relay device of the present embodiment, when the operation state of the information source device is included in the management target of the management device, the communication control unit can perform relay processing of extracting the state information of the information source device from the received frame of the second communication unit and outputting a transmission frame including the extracted state information to the first communication unit, and regarding the relay processing of the state information, it is preferable to execute regardless of whether the first and second conditions are satisfied. The reason is that when the operation state of the information source device is the management target of the management device, the state information of the information source device should be preferentially transmitted to the management device.

[0023] (10) The system according to this embodiment is a traffic management system including the roadside relay devices (1) to (9) described above. Therefore, the traffic management system of this embodiment has the same operational effects as the roadside relay devices (1) to (9) described above.

[0024] (11) The method according to this embodiment is a log collection method executed by the roadside relay devices (1) to (9) described above. Therefore, the log collection method of this embodiment has the same operational effects as the roadside relay devices (1) to (9) described above.

[0025] <Details of Embodiments of the Present Disclosure> Hereinafter, details of embodiments of the present disclosure will be described with reference to the drawings. Note that at least a part of the embodiments described below may be arbitrarily combined.

[0026] 〔Overall Configuration of System〕 FIG. 1 is a block diagram showing an example of the overall configuration of a traffic control system 10. As shown in FIG. 1, the traffic control system 10 of this embodiment includes a central device 1 and a plurality of communication devices 2 and 3 which are roadside communication nodes that communicate with the central device 1.

[0027] The central device 1 of this embodiment also functions as the "management device" of the provision information S2 for vehicles described later. In this sense, it can also be said that the traffic control system 10 is a "traffic management system 11" for managing the provision information S2 for vehicles. The plurality of communication devices 2 and 3 include one or more roadside relay devices 2 and one or more information source devices 3 connected to the roadside relay devices 2.

[0028] The information source devices 3 connected to the roadside relay devices 2 include at least one of a traffic signal controller 3A and a roadside sensor 3B. Traffic control devices other than the illustrated information source devices 3, such as ultrasonic vehicle sensors and traffic information boards, may be connected to the roadside relay devices 2. The central device (management device) 1 is installed at a traffic control center or the like. The roadside relay device 2 is installed at an intersection or a road relatively far from the central device 1. The information source device 3 is installed at an intersection or a road relatively close to the roadside relay device 2.

[0029] In the present embodiment, when focusing on one communication device 2, 3, the communication performed on the central device 1 side (the left side in FIG. 1) as viewed from the own device is referred to as "upper-side communication", and the communication path and transmission method adopted for the upper-side communication are referred to as "upper-side communication path" and "upper-side transmission method", respectively. Similarly, when focusing on one communication device 2, 3, the communication performed on the side opposite to the central device 1 as viewed from the own device (the right side in FIG. 1) is referred to as "lower-side communication", and the communication path and transmission method adopted for the lower-side communication are referred to as "lower-side communication path" and "lower-side transmission method", respectively.

[0030] The upper-side transmission method of the roadside relay device 2 is, for example, the "UD type transmission method". The UD type transmission method is a transmission method capable of IP (Internet Protocol) communication in accordance with the "UD type interface standard" defined by the New Traffic Management System Association (UTMS Association). The lower-side transmission method of the roadside relay device 2 is, for example, the "U type transmission method". The U type transmission method is a serial communication transmission method that cannot perform IP communication in accordance with the "U type interface standard" defined by the UTMS Association.

[0031] The lower-side transmission method of the roadside relay device 2 is not limited to the U type transmission method, and may be other transmission methods defined by the UTMS Association (for example, the M type transmission method or the S9 type transmission method). The lower-side transmission method of the roadside relay device 2 may be the same method as the upper-side transmission method (for example, the UD type transmission method). When two or more information source devices 3 are connected to one roadside relay device 2, the lower-side transmission method may have at least two types of transmission methods mixed.

[0032] The central device 1 is composed of, for example, a server device, and has a communication device (not shown) capable of communicating based on a predetermined lower-level transmission method. The roadside relay device 2 is a communication device having a relay function for communication between the central device 1 and the information source device 3. The upper-level communication path of the roadside relay device 2 is a wired medium (communication cable) 4 such as a dedicated line. A communication node such as a router may be interposed between the central device 1 and the roadside relay device 2. Also, the upper-level communication path of the roadside relay device 2 may include a wireless medium conforming to a standard such as LTE (Long Term Evolution) or the fifth-generation mobile communication system (5G).

[0033] The lower-level communication path of the roadside relay device 2 includes a wired medium (communication cable) 5 such as a dedicated line or a private line. Therefore, at least one information source device 3 can be connected to the roadside relay device 2 via the wired medium 5. The lower-level communication path of the roadside relay device 2 also includes a wireless medium 6. The roadside relay device 2 can also communicate wirelessly with a vehicle 7 traveling on the road via the wireless medium 6. The wireless medium 6 is composed of, for example, a wireless medium in a predetermined frequency band conforming to a standard such as ITS (Intelligent Transport Systems) or LTE (Long Term Evolution).

[0034] The traffic signal controller 3A is a control device that controls the power supply to the traffic signal lights at an intersection. The central device 1 generates control information for the traffic signal controller 3A and transmits it to the roadside relay device 2. The roadside relay device 2 transfers the received control information to the traffic signal controller 3A. The traffic signal controller 3A determines the timing of switching the light color of the traffic signal lights according to the received control information. The control information generated by the central device 1 is, for example, a signal control command defined in the "U-shaped traffic signal controller U-shaped communication application standard" determined by the UTMS Association.

[0035] The traffic signal controller 3A can generate status information S1 indicating the operating state (such as control information) of itself. The traffic signal controller 3A transmits its status information S1 to the roadside relay device 2. The roadside relay device 2 transfers the received status information S1 to the central device 1. The status information (control information) S1 generated by the traffic signal controller 3A is, for example, signal control execution information and signal operation status information defined in the above-mentioned "U-shaped traffic signal controller U-shaped communication application standard".

[0036] The traffic signal controller 3A can generate signal information representing the current or future light color state of the signal lamp. The traffic signal controller 3A transmits the generated signal information to the roadside relay device 2. The signal information is a type of information provided for vehicles (hereinafter may be abbreviated as "provided information" S2). Therefore, the roadside relay device 2 provides the signal information to the vehicle 7 traveling on the road by wirelessly transmitting (for example, broadcasting) the received signal information.

[0037] The roadside sensor 3B is composed of, for example, an image-type vehicle sensor or a millimeter-wave radar, and can generate sensor information including the current positions of moving objects (such as the vehicle 7 and the pedestrian 8) on the road. The roadside sensor 3B transmits the sensor information to the roadside relay device 2. The roadside sensor 3B can generate status information S1 indicating the operating state (such as the presence or absence of a fault) of itself. The roadside sensor 3B transmits its status information S1 to the roadside relay device 2. The roadside relay device 2 transfers the received status information S1 to the central device 1.

[0038] The sensor information is a type of information provided for vehicles S2. Therefore, the roadside relay device 2 provides the sensor information to the vehicle 7 traveling on the road by wirelessly transmitting (for example, broadcasting) the received sensor information. The provided information S2 in this embodiment is dynamic information. Dynamic information refers to dynamic data that requires a delay time within 1 second. For example, sensor information including the current position of a moving object and signal information utilized as ITS pre-read information correspond to dynamic information.

[0039] Vehicle 7 has an in-vehicle device that communicates using the wireless medium 6. The in-vehicle device includes a navigation device that alerts the driver by screen display or voice using the vehicle-provided information (such as signal information and sensor information) S2 provided from the roadside relay device 2. When vehicle 7 is, for example, a level 4 or higher automated driving vehicle, the vehicle-provided information (such as signal information and sensor information) S2 is also used for the control of automated driving.

[0040] The in-vehicle device of vehicle 7 enables vehicle-to-vehicle communication and road-to-vehicle communication through a wireless communication system such as ITS or LTE-V2X (Vehicle to X). The transmission information of vehicle 7 includes vehicle information S3 representing the current position, speed, and driving state of the host vehicle. When the roadside relay device 2 receives the vehicle information S3 from vehicle 7, it can transfer the received vehicle information S3 to the central device 1. However, the transfer of the vehicle information S3 to the central device 1 may not be performed. Note that the content of the vehicle information S3 (Figure 5) used for determining whether to collect the provided information S2 will be described later.

[0041] 〔Internal Configuration of Roadside Relay Device〕 Figure 2 is a block diagram showing an example of the internal configuration of the roadside relay device 2. As shown in Figure 2, the roadside relay device 2 includes a housing 20 and a plurality of electronic devices housed in the housing 20. The plurality of electronic devices includes an upper-side communication unit 21, a plurality of lower-side communication units 22, 23, a communication control unit 24, a storage unit 25, and a synchronization processing unit 26. Each of the communication units 21 to 23, the storage unit 25, and the synchronization processing unit 26 is electrically connected to the communication control unit 24.

[0042] Among the plurality of lower-side communication units 22, 23, the lower-side communication unit 22 is a communication interface (wired communication unit) that transmits and receives transmission signals via the wired medium 5. The lower-side communication unit 23 is a communication interface (wireless communication unit) that transmits and receives transmission signals via the wireless medium 6. In Fig. 2, two lower - side wired communication units 22 are illustrated as examples, but three or more wired communication units 22 may be mounted on one roadside relay device 2.

[0043] The upper - side communication unit 21 is a communication interface (first communication unit) for communication with the central device 1. The upper - side communication unit 21 executes predetermined signal processing (such as modulation / demodulation and AD / DA conversion) based on the upper - side transmission method. The lower - side communication unit 22 is a communication interface (second communication unit) for communication with the information source devices 3 (traffic signal controller 3A and roadside sensor 3B in Fig. 2). The lower - side communication unit 22 executes predetermined signal processing (such as modulation / demodulation and AD / DA conversion) based on the lower - side transmission method.

[0044] The lower - side communication unit 23 is a communication interface (third communication unit) for communication with the vehicle 7. The lower - side communication unit 23 executes predetermined signal processing (such as modulation / demodulation and AD / DA conversion) based on the lower - side transmission method.

[0045] The upper - side communication unit (first communication unit) 21 demodulates the transmission signal (carrier signal) input from the upper - side communication path composed of the wired medium 4 to reproduce the received frame. The upper - side communication unit 21 outputs the reproduced received frame to the communication control unit 24. The upper - side communication unit (first communication unit) 21 modulates the transmission frame input from the communication control unit 24 into a transmission signal of a predetermined frequency. The upper - side communication unit 21 outputs the modulated transmission signal to the upper - side communication path composed of the wired medium 4.

[0046] The lower - side communication unit (second communication unit) 22 demodulates the transmission signal (carrier signal) input from the lower - side communication path composed of the wired medium 5 to reproduce the received frame. The lower - side communication unit 22 outputs the reproduced received frame to the communication control unit 24. The lower - side communication unit (second communication unit) 22 modulates the transmission frame input from the communication control unit 24 into a transmission signal of a predetermined frequency. The lower - side communication unit 22 outputs the modulated transmission signal to the lower - side communication path composed of the wired medium 5.

[0047] The lower - side communication unit (the third communication unit) 23 demodulates the transmission signal (carrier signal) input from the lower - side communication path composed of the wireless medium 6 and regenerates the received frame. The lower - side communication unit 23 outputs the regenerated received frame to the communication control unit 24. The lower - side communication unit (the third communication unit) 23 modulates the transmission frame input from the communication control unit 24 into a transmission signal of a predetermined frequency. The lower - side communication unit 23 sends the modulated transmission signal to the lower - side communication path composed of the wireless medium 6.

[0048] The communication control unit 24 is composed of an arithmetic processing device including a CPU (Central Processing Unit) and a RAM (Random Access Memory), etc. The communication control unit 24 may include an integrated circuit such as an FPGA (Field - Programmable Gate Array). The communication control unit 24 reads the computer program stored in the storage unit 25 into the main memory (RAM) and performs various information processes according to the program.

[0049] The storage unit 25 is composed of an auxiliary storage device including non - volatile memories such as an HDD (Hard Disk Drive) and an SDD (Solid State Drive). The storage unit 25 may include a flash ROM (Read Only Memory), a USB (Universal Serial Bus) memory, or an SD card, etc.

[0050] The communication control unit 24 has a relay function for communication frames. Specifically, the communication control unit 24 determines to which of the communication units 21 - 23 to output the transmission frame including the information extracted from the received frame input from the communication units 21 - 23 according to the preset path information. The communication control unit 24 has a format conversion function for communication frames. Specifically, the communication control unit 24 performs format conversion from the upper - side transmission method to the lower - side transmission method on the down - link frame relayed from the upper - side communication unit 21 to the lower - side communication units 22, 23.

[0051] Conversely, the communication control unit 24 performs format conversion from the lower-side transmission method to the upper-side transmission method on the upstream frame relayed from the lower-side communication units 22 and 23 to the upper-side communication unit 21. However, when the upper-side transmission method and the lower-side transmission method are the same (for example, when both are the UD type transmission method), the communication control unit 24 does not perform the above format conversion, and routing based on the MAC address, IP address, etc. is performed.

[0052] In the roadside relay device 2 of the present embodiment, the communication control unit 24 performs the following relay processes 1 to 3 for each of the above pieces of information S1 to S3. Relay process 1: Relay the status information S1 from the lower-side communication unit 22 to the upper-side communication unit 21 Specifically, when the received frame input from the lower-side communication unit 22 includes the status information S1, the communication control unit 24 generates a transmission frame including the status information S1 extracted from the received frame, and outputs the generated transmission frame to the upper-side communication unit 21.

[0053] Relay process 2: Relay the provided information S2 from the lower-side communication unit 22 to the lower-side communication unit 23 Specifically, when the received frame input from the lower-side communication unit 22 includes the provided information S2, the communication control unit 24 generates a transmission frame including the provided information S2 extracted from the received frame, and outputs the generated transmission frame to the lower-side communication unit 23.

[0054] Relay process 3: Relay the vehicle information S3 from the lower-side communication unit 23 to the upper-side communication unit 21 Specifically, when the received frame input from the lower-side communication unit 22 includes the vehicle information S3, the communication control unit 24 generates a transmission frame including the vehicle information S3 extracted from the received frame, and outputs the generated transmission frame to the upper-side communication unit 21.

[0055] However, as an operation mode of the traffic control system 10, there may be a case where the above relay process is not executed. In this embodiment, the communication control unit 24 of the roadside relay device 2 can also execute "limited log collection" regarding the provision information S2 for vehicles. The details of this process will be described later.

[0056] The synchronization processing unit 26 is a processing unit for achieving time synchronization with other communication nodes such as the central device 1 by a predetermined synchronization method. The communication control unit 24 determines the reception time and transmission timing of communication frames according to the local time generated by the synchronization processing unit 26. As the synchronization method of the synchronization processing unit 26, for example, a synchronization method based on the output of a GNSS (Global Navigation Satellite System) receiver, a synchronization method using communication frames such as NTP (Network Time Protocol) and PTP (Precision Time Protocol), etc. can be adopted.

[0057] 〔Necessity and problems of management of provision information〕 In the current traffic control system 10, in many cases, the management target of the central device 1 is only the status information (control information, presence or absence of failure, etc.) S1 of the information source device 3, and the provision information S2 for vehicles is not the management target of the central device 1. In this case, for example, as shown in FIG. 1, the roadside relay device 2 wirelessly transmits the provision information (signal information, sensor information, etc.) S2 for vehicles received from the information source device 3 to the vehicle 7 by broadcast or the like, but does not transmit it to the central device 1.

[0058] However, when autonomous driving (especially at level 4 or above) using the provision information S2 becomes widespread, in order to determine whether the cause of a traffic accident is on the infrastructure side or the vehicle side, it becomes important what kind of provision information S2 was provided at what timing. In addition, as the spread of the safe driving support system progresses, even when the driver is a human, there may be a lawsuit in which it is claimed that the provision information S2 is the cause of an accident. Therefore, there is a demand that the provision information S2 for vehicles should also be the management target of the central device 1.

[0059] Therefore, it is conceivable that the roadside relay device 2 wirelessly transmits the provision information S2 for the vehicle to the central device 1 while also transmitting it to the central device 1, and the central device 1 stores the received provision information S2 for the vehicle in the storage device. However, since the provision information S2 such as signal information and sensor information is dynamic information with a large temporal change, it is wirelessly transmitted at a relatively short cycle (for example, at intervals of 100 ms) so that the vehicle 7 can perform real-time processing.

[0060] For this reason, in the method where the roadside relay device 2 simply transmits the provision information S2 consisting of dynamic information to the central device 1, it is necessary to connect the central device 1 and the roadside relay device 2 with a broadband line, and a storage device with a huge data capacity is required. Therefore, there is a problem that the line cost and the equipment cost become high.

[0061] 〔Outline of Limited Log Collection〕 In view of the above problems, in the present embodiment, the communication control unit 24 of the roadside relay device 2 determines the presence or absence of the vehicle 7 that can use the provision information S2 based on the vehicle information S3, and performs log collection of the provision information S2 only when the vehicle 7 exists. This is "limited log collection". In this way, if only the provision information S2 that can actually be used is collected, it can be transmitted to the central device 1 even with a relatively low-speed communication line, and the data capacity of the storage device of the central device 1 can also be reduced.

[0062] FIG. 3 is a flowchart showing an example of limited log collection. The communication control unit 24 of the roadside relay device 2 executes the process of FIG. 3 for each provision information S2 during operation. Further, the communication control unit 24 executes the process of FIG. 3 at a cycle equal to or shorter than the transmission cycle (for example, 100 ms) of the provision information S2 for the vehicle. Hereinafter, the vehicle 7 estimated to have the possibility of using the provision information S2 for the vehicle is referred to as the "target vehicle", and the vehicle 7 estimated to have no possibility of using the provision information S2 for the vehicle is referred to as the "non-target vehicle".

[0063] As shown in FIG. 3, the communication control unit 24 first determines whether it has received the vehicle-provided information S2 from the information source device 3 (step ST11). This determination is made, for example, based on whether a received frame including the provided information S2 has been input from the lower-level communication unit 22. If the determination result in step ST11 is negative, the communication control unit 24 ends the process. If the determination result in step ST11 is positive, the communication control unit 24 determines whether the "first condition" is satisfied (step ST12).

[0064] The first condition is one of the conditions for stating that there is a target vehicle (leading to the availability of the provided information S2). In the present embodiment, the first condition is that the vehicle 7 exists within the service target area of the provided information S2. The "service target area" is an area on the road set for each provided information S2. Since a vehicle 7 outside the area cannot appropriately use the provided information S2 even if it receives it, the presence of the vehicle 7 within the area is one of the conditions for stating that there is a target vehicle.

[0065] For example, in the case of a service that provides signal information on the inflow road in the first direction among the four inflow roads at a crossroads intersection, the service target area is the road section from the stop line on the inflow road in the first direction to a point upstream by a predetermined distance (for example, 150 m). In the case of a service that provides the vehicle 7 with sensor information including the current position of the pedestrian 8 passing through the crosswalk at the right turn destination, the service target area is the road section corresponding to, for example, the length of the right turn lane on the inflow road.

[0066] In the case of a service that provides the vehicle 7 with sensor information including the current position of the pedestrian 8 passing through the crosswalk at the left turn destination, the service target area is the road section from the stop line on the inflow road including the left turn lane to a point upstream by a predetermined distance (for example, 80 m). In the case of a service that provides sensor information including the current position of other vehicles traveling on intersecting roads to vehicle 7 in order to prevent collision accidents at signal - free intersections, the service target area is a road section from a point upstream of the intersection by a predetermined distance (for example, 80 m) to a certain point.

[0067] When the determination result of step ST12 is negative, the communication control unit 24 ends the process. When the determination result of step ST12 is positive, the communication control unit 24 further determines whether the "second condition" is satisfied (step ST13). Thus, in this embodiment, as one of the conditions for being able to say that there is a target vehicle (leading to the availability of the provided information S2), a second condition different from the first condition is added.

[0068] The reason is that even when vehicle 7 is in a state of being within the service target area (a state satisfying the first condition), for example, if vehicle 7 rejects the service by the provided information S2, the provided information S2 is not used. Specific examples of the second condition to be added to the first condition exist in plurality according to the type of vehicle information S3. Details of the second condition will be described later.

[0069] When the determination result of step ST13 is negative, the communication control unit 24 ends the process. When the determination result of step ST13 is positive, the communication control unit 24 executes log collection of the provided information S2 (step ST14). The log collection of the provided information S2 is a process of adding time information to the acquired provided information S2, dividing the provided information S2 with time information by type, and storing it in the storage unit 25. The time information is, for example, the reception time (date and time) of the reception frame including the provided information S2.

[0070] When the data accumulation amount of the provided information S2 with time information in the communication control unit 24 of the roadside relay device 2 reaches a predetermined amount or more, the communication control unit 24 reads out the provided information S2 from the storage unit 25 and transmits it to the central device 1. Specifically, the communication control unit 24 generates a transmission frame including the provided information S2 read from the storage unit 25, and inputs the generated transmission frame to the upper communication unit 21. It is preferable to execute the transmission process of such provided information S2 during a time period when the communication bandwidth of the upper communication path is not congested.

[0071] 〔Communication State Change of Road-Side Relay Device〕 FIG. 4 is an explanatory diagram showing the communication state change of the road-side relay device 2. As shown in FIG. 4, when a target vehicle exists (when there is availability of the provided information S2), the road-side relay device 2 executes log collection of the provided information S2. Thereafter, the road-side relay device 2 transmits the provided information S2 with the collected time information to the central device 1. The central device 1 accumulates the provided information S2 with the time information received from the road-side relay device 2 in its own database.

[0072] When no target vehicle exists (when there is no availability of the provided information S2), that is, when only non-target vehicles exist or there are no vehicles, the road-side relay device 2 does not execute log collection of the provided information S2. The determination of whether there are no vehicles can be made, for example, by the fact that vehicle information S3 has not been continuously received over a predetermined period (for example, 2 minutes).

[0073] Note that the road-side relay device 2 executes the following relay processes 1 and 2 regardless of whether a target vehicle exists or not. Also, in the case of an operation in which the road-side relay device 2 executes the following relay process 3, the road-side relay device 2 executes the relay process 3 regardless of whether a target vehicle exists or not. Relay Process 1: State Information S1 from Information Source Device 3 → Relay to Central Device 1 Relay Process 2: Provided Information S2 from Information Source Device 3 → Relay to Vehicle 7 Relay Process 3: Vehicle Information S3 from Vehicle 7 → Relay to Central Device 1

[0074] 〔Specific Example of Vehicle Information〕 FIG. 5 is a table showing an example of the vehicle information S3 used for determining the existence or non-existence of a target vehicle. As shown in FIG. 5, the items of the vehicle information S3 transmitted by the vehicle 7 include "travel position", "vehicle type", "service type", "service setting status", "travel direction", and "planned route information".

[0075] The "travel position" is position information (latitude, longitude, altitude, etc.) representing the current position of the vehicle 7. The position information of the vehicle 7 is obtained from a GNSS receiver or the like included in the in-vehicle device of the vehicle 7. The "vehicle type" is identification information for identifying the vehicle 7 by size and use. The contents of the vehicle type include, for example, motorcycles, ordinary vehicles, large vehicles, private cars, freight vehicles, taxis, route buses, ambulances, and police cars.

[0076] The "service type" is identification information representing the service actually used by the vehicle 7 among the services provided by the infrastructure side. The contents of the service type include, for example, information provision service on the current lighting state of traffic lights, information provision service on the future lighting state of traffic lights, information provision service on crosswalk pedestrians, etc. The "service setting status" is identification information representing the permission or rejection status of service use, set by the user of the vehicle 7. "Service setting status = ON" represents service permission, and "service setting status = OFF" represents service rejection.

[0077] The "travel direction" is angle information representing the travel direction of the vehicle 7 during travel. The travel direction is represented by an angle clockwise with true north as 0 degrees, for example. The travel direction is obtained from a GNSS receiver or a gyro sensor included in the in-vehicle device of the vehicle 7. The "planned route" is route information planned for the vehicle 7 to travel. The planned route information is composed of, for example, link data corresponding to roads and node data corresponding to intersections.

[0078] 〔Conditions for determining the existence of the target vehicle〕 FIG. 6 is a table summarizing the types and contents of the conditions used for determining the existence of the target vehicle. As shown in FIG. 6, the types of conditions include the "area condition" which is the first condition, and the "vehicle type condition", "service type condition", "status condition", "orientation condition", and "route condition" which are the second conditions.

[0079] The area condition (first condition) is that the running position of the vehicle information S3 exists within the service target area. Therefore, when the running position does not exist within the service target area, the roadside relay device 2 does not execute the log collection of the provided information S2 that adopts the service target area. FIG. 7 is an explanatory diagram showing a determination example based on the area condition (first condition). The "wireless antenna" in FIG. 7 indicates the antenna position of the roadside relay device 2, and the "wireless area" indicates the radio wave reception area of the roadside relay device 2. This is the same for FIGS. 8 to 12.

[0080] As shown in FIG. 7, assume an intersection J1 where the service target area is set on the northward (upward in FIG. 7) inflow road. In this case, by the determination based on the area condition (first condition), when the running position of the vehicle information S3 is within the service target area, the log collection of the provided information S2 that adopts the area can be executed. Conversely, when the running position of the vehicle information S3 is outside the service target area, the log collection of the provided information S2 that adopts the area is not executed.

[0081] The vehicle type condition (second condition) is that the vehicle type of the vehicle information S3 matches the service target vehicle type on the infrastructure side. Therefore, at intersections where services limited to specific vehicle types (for example, route buses) are provided, when there is no vehicle 7 of the specific vehicle type, the roadside relay device 2 does not execute the log collection of the provided information S2 regarding the service.

[0082] FIG. 8 is an explanatory diagram showing a determination example based on the vehicle type condition (second condition). As shown in FIG. 8, assume an intersection J2 that provides services for private cars. In this case, based on the determination according to the vehicle type condition (the second condition), when the vehicle type in the vehicle information S3 is a private car, the log collection of the service provision information S2 for private cars can be executed. Conversely, when the vehicle type in the vehicle information S3 is a route bus, the log collection of the service provision information S2 for private cars is not executed.

[0083] The service type condition (the second condition) is that the service type in the vehicle information S3 matches the service type on the infrastructure side. Therefore, when there is no vehicle 7 using a specific service at an intersection where the specific service (for example, a signal information provision service) is provided, the roadside relay device 2 does not execute the log collection of the service provision information S2 for the service.

[0084] FIG. 9 is an explanatory diagram showing a determination example based on the service type (the second condition). As shown in FIG. 9, assume a case where the service type used by the vehicle 7 is a signal information service. In this case, based on the determination according to the service type condition (the second condition), when it is the intersection J3 where the service type being provided is the signal information service, the log collection of the service provision information S2 for the signal information service can be executed. Conversely, when it is the intersection J4 where the service type being provided is a pedestrian information service, the log collection of the service provision information S2 for the pedestrian information service is not executed.

[0085] The state condition (the second condition) is that the service setting state in the vehicle information S3 is ON (service permitted). Therefore, when there is no vehicle 7 whose service setting state is being set to ON, the roadside relay device 2 does not execute the log collection of the service provision information S2 regarding the service.

[0086] FIG. 10 is an explanatory diagram showing a determination example based on the state condition (the second condition). As shown in FIG. 10, assume an intersection J5 that provides a signal information service. In this case, based on the determination according to the state condition (second condition), when the service setting state of the vehicle information S3 is ON (service permitted), the log collection of the provision information S2 of the signal information service can be executed. Conversely, when the service setting state of the vehicle information S3 is OFF (service prohibited), the log collection of the provision information S2 of the signal information service is not executed.

[0087] The azimuth condition (second condition) is that the traveling azimuth of the vehicle information S3 coincides with the service target azimuth on the infrastructure side. Therefore, when there is no vehicle 7 traveling toward the service target azimuth defined for each service, the roadside relay device 2 does not execute the log collection of the provision information S2 that adopts the service target azimuth.

[0088] FIG. 11 is an explanatory diagram showing a determination example based on the azimuth condition (second condition). As shown in FIG. 11, assume an intersection J6 where the service target azimuth is set to the north direction of the inflow road (the upward direction in FIG. 7). In this case, based on the determination according to the azimuth condition (second condition), when the traveling azimuth of the vehicle information S3 coincides with the service target azimuth, the log collection of the provision information S2 that adopts the target azimuth can be executed. Conversely, when the traveling azimuth of the vehicle information S3 does not coincide with the service target azimuth, the log collection of the provision information S2 that adopts the target azimuth is not executed.

[0089] The route condition (second condition) is that the planned route of the vehicle information S3 coincides with the service target route on the infrastructure side. Therefore, when there is no vehicle 7 traveling on the service target route defined for each service, the roadside relay device 2 does not execute the log collection of the provision information S2 that adopts the service target route.

[0090] FIG. 12 is an explanatory diagram showing a determination example based on the route condition (second condition). As shown in FIG. 12, assume an intersection J7 where the service target route is set to a route that goes straight northward (upward in FIG. 12) at the intersection J7. In this case, based on the determination according to the route condition (the second condition), when the planned route (going straight) of the vehicle information S3 matches the service target route (going straight), the log collection of the provided information S2 that adopts the target route can be executed. Conversely, when the planned route (turning right) of the vehicle information S3 does not match the service target route (going straight), the log collection of the provided information S2 that adopts the target route is not executed.

[0091] As is clear from the above, summarizing the content of the "limited log collection" executed by the communication control unit 24 of the roadside relay device 2 is as follows. The communication control unit 24 of the roadside relay device 2 determines whether the "first condition" (area condition) and the "second condition" (at least one of the vehicle type condition, service type condition, state condition, azimuth condition, and route condition) are satisfied for each type of the provided information S2 for vehicles, and executes the log collection of the provided information S2 of the type only when the determination result is affirmative.

[0092] However, the limited log collection executed by the communication control unit 24 of the roadside relay device 2 is not limited to the process of taking the first condition and the second condition as AND conditions, and may be a process performed when any one of the conditions is satisfied. That is, the communication control unit 24 of the roadside relay device 2 may execute log collection when only the first condition is satisfied or when only the second condition is satisfied.

[0093] [Modification example of traffic management system] FIG. 13 is a block diagram showing a modification example of the traffic management system 11. In the modification example of FIG. 13, the traffic management system 11 is composed of a communication network of a different system from the traffic control system 10 including the central device 1. That is, the traffic management system 11 includes a management device 12 which is a server device different from the central device 1, a roadside relay device 2, and an information source device 3. Therefore, the roadside relay device 2 belongs to the traffic management system 11 but does not belong to the traffic control system 10.

[0094] The information source device 3 connected to the roadside relay device 2 includes at least one of the traffic signal controller 3A and the roadside sensor 3B. The traffic control system 10 includes a central device 1 installed in a traffic control center or the like, and a traffic signal controller 3A that communicates with the central device 1 via a dedicated network 13. In the example of FIG. 13, the roadside sensor 3B is not connected to the dedicated network 13, but the roadside sensor 3B may be connected to the network 13.

[0095] The management device 12 is a server device such as an on-premises server or a cloud server, and has a communication device (not shown) capable of communicating based on a predetermined lower-side transmission method. The roadside relay device 2 is a communication device having a relay function for communication between the management device 12 and the information source device 3. The management device 12 and the roadside relay device 2 are connected via a public network 14 including the Internet. Note that the upper-side communication path of the roadside relay device 2 may include a wireless medium conforming to a standard such as LTE or 5G.

[0096] The lower-side communication path of the roadside relay device 2 includes a wired medium (communication cable) 5 such as a dedicated line or a private line. Therefore, at least one information source device 3 can be connected to the roadside relay device 2 via the wired medium 5. Note that the roadside relay device 2 may communicate with the information source device 3 via a wireless medium 6. The lower-side communication path of the roadside relay device 2 also includes a wireless medium 6. The roadside relay device 2 can also wirelessly communicate with a vehicle 7 traveling on the road via the wireless medium 6. The wireless medium 6 is composed of, for example, a wireless medium in a predetermined frequency band conforming to a standard such as ITS or LTE.

[0097] The traffic signal controller 3A transmits the status information S1 of its own device to the central device 1 of the traffic control system 10, but transmits the signal information to the roadside relay device 2 of the traffic management system 11. The signal information is a type of the information S2 provided for vehicles. Therefore, the roadside relay device 2 wirelessly transmits (for example, broadcasts) the received signal information to provide the signal information to the vehicle 7 traveling on the road.

[0098] The roadside sensor 3B transmits the sensor information to the roadside relay device 2. The sensor information is a type of the information S2 provided for vehicles. Therefore, the roadside relay device 2 wirelessly transmits (for example, broadcasts) the received sensor information to provide the sensor information to the vehicle 7 traveling on the road. The in-vehicle device of the vehicle 7 can perform vehicle-to-vehicle communication and vehicle-to-roadside communication through a wireless communication system such as ITS or LTE-V2X. The transmission information of the vehicle 7 includes vehicle information S3 representing the current position, speed, and driving state of the host vehicle.

[0099] The vehicle information S3 includes, for example, the information shown in FIG. 5 and is used for determining whether to collect the log of the provided information S2. Specifically, the roadside relay device 2 shown in FIG. 13 also has a communication control unit 24 (see FIG. 2) capable of executing the above-mentioned "limited log collection". That is, the communication control unit 24 determines the presence or absence of the vehicle 7 that can use the provided information S2 based on the vehicle information S3, and performs the log collection of the provided information S2 only when the vehicle 7 exists. The collected provided information S2 is transmitted to the management device 12 and stored in the database.

[0100] [Other Modification Examples] The embodiments disclosed this time are illustrative in all respects and not restrictive. The scope of the rights of the present invention is not limited to the above-described embodiments, but includes all modifications within the scope equivalent to the configurations described in the claims. For example, in the above-described embodiment, an external type wireless communication device may be adopted as the lower-level communication unit (wireless communication unit) 23 of the roadside relay device 2, and the wireless communication device may be connected to the lower-level connection unit 22 by a communication cable.

[0101] In the above-described embodiment, the case where the upper-side communication unit (first communication unit) 21, the lower-side communication unit (second communication unit) 22, and the lower-side communication unit (third communication unit) 23, which are components of the roadside relay device 2, are composed of three communication interfaces (devices) has been exemplified. However, these communication units 21 to 23 may be communication units integrated into one or two devices, for example, where the layers 3 and below of the OSI reference model are common.

Explanation of Signs

[0102] 1 Central device (management device) 2 Roadside relay device (communication device) 3 Information source device (communication device) 3A Traffic signal controller (information source device) 3B Roadside sensor (information source device) 4 Wired medium (communication cable) 5 Wired medium (communication cable) 6 Wireless medium 7 Vehicle 8 Pedestrian 10 Traffic control system (traffic management system) 11 Traffic management system 12 Management device 13 Dedicated network 14 Public network 20 Housing 21 Upper-side communication unit (wired communication unit, first communication unit) 22 Lower-side communication unit (wired communication unit, second communication unit) 23 Lower-side communication unit (wireless communication unit, third communication unit) 24 Communication control unit 25 Storage unit 26 Synchronization processing unit S1 Status information S2 Provision information for vehicles S3 Vehicle information

Claims

1. a first communication unit for communicating with a management device; a second communication unit for communicating with an information source device; a third communication unit for communicating with a vehicle; a communication control unit configured to extract vehicle-provided information from a received frame of the second communication unit and output a transmission frame including the extracted provided information to the third communication unit; wherein the communication control unit is a roadside relay device that determines whether a condition leading to the availability of the provided information is satisfied based on vehicle information included in a received frame of the third communication unit, and executes log collection of the provided information when the condition is satisfied.

2. The roadside relay device according to claim 1, wherein the condition includes at least one of the following first condition and second condition. First condition: the vehicle is present within a service target area for vehicle-provided information Second condition: a condition different from the first condition leading to the availability of vehicle-provided information

3. the vehicle information includes the traveling position of the vehicle, wherein the communication control unit determines whether the first condition is satisfied based on whether the traveling position is within the service target area, according to the roadside relay device of claim 2.

4. the vehicle information includes the vehicle type of the vehicle, wherein the second condition includes the vehicle type matching the service target vehicle type on the infrastructure side, according to the roadside relay device of claim 2 or claim 3.

5. the vehicle information includes the service type being used by the vehicle, wherein the second condition includes the service type matching the service type on the infrastructure side, according to any one of claims 2 to 4 of the roadside relay device.

6. the vehicle information includes a service setting state indicating permission or rejection of service use, wherein the second condition includes the service setting state being permission, according to any one of claims 2 to 5 of the roadside relay device.

7. the vehicle information includes the traveling direction of the vehicle, wherein the second condition includes the traveling direction matching the service target direction on the infrastructure side, according to any one of claims 2 to 6 of the roadside relay device.

8. the vehicle information includes the planned route of the vehicle, wherein the second condition includes the planned route matching the service target route on the infrastructure side, according to any one of claims 2 to 7 of the roadside relay device.

9. the management target of the management device includes the operating state of the information source device, wherein the communication control unit It is possible to perform relay processing for extracting the status information of the information source device from the received frame of the second communication unit and outputting a transmission frame including the extracted status information to the first communication unit. The roadside relay device according to any one of claims 1 to 8, wherein the relay processing of the status information is executed regardless of whether the condition is satisfied.

10. A management device, A roadside relay device that communicates with the management device, A traffic management system comprising an information source device that communicates with the management device via the roadside relay device, wherein The roadside relay device, Relay processing for wirelessly transmitting vehicle-provided information received from the information source device to the vehicle, Determining whether a condition leading to the availability of the provided information is satisfied based on the vehicle information received from the vehicle, A traffic management system that performs log collection of the provided information that is permitted to be executed when the condition is satisfied.

11. A management device, A roadside relay device that communicates with the management device, A log collection method executed in a traffic management system comprising an information source device that communicates with the management device via the roadside relay device, wherein The roadside relay device wirelessly transmits vehicle-provided information received from the information source device to the vehicle, The roadside relay device determines whether a condition leading to the availability of the provided information is satisfied based on the vehicle information received from the vehicle, The roadside relay device includes steps of performing log collection of the provided information when the condition is satisfied.

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