Roadside Machine

Abstract

To provide a roadside machine capable of identifying an on-vehicle device loading vehicle from among vehicles proceeding to a traffic intersection and providing particular driving support information to the on-vehicle device loading vehicle proceeding to the traffic intersection.SOLUTION: A roadside machine 2 is installed at a traffic intersection and has a roadside machine communication unit 21, a roadside machine memory 22, and a roadside machine control unit 23. The roadside machine 2 comprises: acquiring information of an on-vehicle device loading vehicle, proceeding to a traffic intersection, from an on-vehicle device 3 by radio communication; detecting information of individual vehicles proceeding to the traffic intersection on the basis of output of first to fourth sensor modules 5A to 5D; determining that any one of the individual vehicles is the same vehicle as the on-vehicle device loading vehicle on the basis of the information of the on-vehicle device loading vehicle and the information of the individual vehicles; and transmitting to the on-vehicle device loading vehicle driving support information acquired based on the information of the on-vehicle device loading vehicle and the information of the individual vehicles.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a roadside unit that is installed at an intersection and can configure an intersection driving support system in cooperation with an on-board device mounted on a vehicle (particularly an autonomous vehicle). [Background technology]

[0002] Patent document 1 describes an on-board device that acquires detection information from an object detection sensor transmitted from a roadside unit installed at an intersection, and outputs an alarm if it determines, based on the acquired detection information, that an object is present or is moving in the direction in which the vehicle is traveling across the oncoming lane at the intersection. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-58868 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the technology described in Patent Document 1, the vehicle-mounted device needs to extract and process information corresponding to the vehicle itself from the detection information transmitted from the roadside device, which results in a large processing load. Therefore, the applicant is considering providing driving assistance to a vehicle equipped with the vehicle-mounted device (i.e., a vehicle equipped with an on-board device) by providing individual information from the roadside device to the vehicle-mounted device. In this case, the roadside device needs to identify the vehicle equipped with the on-board device, but cannot identify the vehicle equipped with the on-board device based only on the detection information from the object detection sensor.

[0005] The present invention has been made in consideration of the above circumstances, and aims to provide a roadside unit that can identify vehicles equipped with on-board units from among vehicles heading toward an intersection, and can provide individual driving assistance information to vehicles equipped with on-board units heading toward the intersection. [Means for solving the problem]

[0006] According to one aspect of the present invention, there is provided a roadside device, which acquires signal control information of a traffic light installed at an intersection, acquires information of a vehicle equipped with an on-board unit heading towards the intersection by wireless communication, detects information of each vehicle heading towards the intersection based on an output of a sensor module, and determines that one of the vehicles is the same vehicle as the on-board unit vehicle based on the information of the on-board unit vehicle and the information of each vehicle; predicting a future position of the vehicle equipped with the on-board unit based on information of the vehicle equipped with the on-board unit and taking into account the signal control information; predicting a future position of each of the vehicles based on information of each of the vehicles and taking into account the signal control information; and comparing the predicted future position of the vehicle equipped with the on-board unit with the predicted future positions of each of the vehicles. The vehicle-mounted device is configured to transmit the obtained driving assistance information to the vehicle equipped with the vehicle-mounted device. Effect of the Invention

[0007] According to the present invention, it is possible to provide a roadside unit that can identify vehicles equipped with on-board units from among vehicles heading toward an intersection, and can provide individual driving assistance information to vehicles equipped with on-board units heading toward the intersection. [Brief description of the drawings]

[0008] [Figure 1] 1 is a block diagram of an intersection driving assistance system according to an embodiment of the present invention. [Diagram 2] 1 is a diagram showing an example of an intersection to which the intersection driving assistance system is applied; [Diagram 3] 13 is a flowchart showing an example of an intersection situation grasping process. [Figure 4] 10 is a flowchart showing an example of a vehicle-mounted device-equipped vehicle recognition process; [Diagram 5] 10 is a diagram for explaining a first contact determination process for a vehicle equipped with an on-board unit heading toward the intersection. FIG. [Figure 6] 6 is a flowchart showing an example of the first contact determination process (including driving support information creation / transmission process). [Figure 7] 10 is a diagram for explaining the second contact determination process for a vehicle equipped with an on-board unit and waiting to turn right within the intersection. FIG. [Figure 8]6 is a flowchart showing an example of the second contact determination process (including driving support information creation / transmission process). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

[0010] Fig. 1 is a block diagram showing a configuration of an intersection driving assistance system according to an embodiment of the present invention. As shown in Fig. 1, the intersection driving assistance system 1 according to the embodiment is mainly composed of a roadside device 2 installed at an intersection and an on-board device 3 mounted on a vehicle. The intersection driving assistance system 1 is configured to transmit driving assistance information related to the intersection from the roadside device 2 to the on-board device 3 (in other words, a vehicle equipped with the on-board device, which is a vehicle equipped with the on-board device 3) by road-to-vehicle communication.

[0011] In the following, a case will be described in which the vehicle equipped with the on-board device is an autonomous vehicle equipped with an autonomous driving device. However, this is not limited to this, and the vehicle equipped with the on-board device may be a driving assistance vehicle equipped with a driving assistance device that assists the driver in driving. In this case, the autonomous driving device in the following description will be read as the driving assistance device.

[0012] Referring to FIG. 1, in this embodiment, the roadside unit 2 has a roadside unit communication unit 21 that performs wireless communication with the outside, a roadside unit memory 22 that stores various information, and a roadside unit control unit 23 that executes various processes.

[0013] The roadside unit 2 also has means for acquiring time information, such as a Global Navigation Satellite System (GNSS) receiver (not shown), and is electrically connected, by wire or wirelessly, to a signal controller 4 that controls a plurality of traffic lights installed at the intersection X, and to a plurality of sensor modules (first to fourth sensor modules 5A to 5D in this case). Therefore, the roadside unit 2 can acquire time information, acquire signal control information from the signal controller 4, and acquire outputs (detection results) of the first to fourth sensor modules 5A to 5D.

[0014] Fig. 2 is a diagram showing an example of an intersection to which the intersection driving assistance system 1 is applied. As shown in Fig. 2, in this embodiment, the intersection X is a four-way (cross) intersection, and first to fourth vehicle traffic lights 41A to 41D and first to fourth pedestrian traffic lights 61A to 61D are installed at the intersection X. These traffic lights 41A to 41D and 61A to 61D are controlled by a traffic light controller 4.

[0015] The first to fourth vehicle traffic lights 41A to 41D are so-called double-sided traffic lights, and have signal lights on both the front and back sides. The first to fourth vehicle traffic lights 41A to 41D are attached to the first to fourth signal poles 43A to 43D via support arms 42A to 42D, respectively. The first to fourth pedestrian traffic lights 61A to 61D are attached to the first to fourth signal poles 43A to 43D via support arms 62A to 62D, respectively.

[0016] The road-side unit 2 and the signal controller 4 are attached, for example, to any of the first to fourth signal poles 43A to 43D (here, the second signal pole 43B). However, this is not limited thereto, and the road-side unit 2 and the signal controller 4 may be attached to different signal poles, or the road-side unit 2 and the signal controller 4 may be integrated (contained in one housing). Alternatively, the road-side unit 2 and / or the signal controller 4 may be installed at a location other than the first to fourth signal poles 43A to 43D.

[0017] The first to fourth sensor modules 5A to 5D monitor the intersection X and a predetermined range of the road leading to the intersection X from an obliquely upward direction. The road leading to the intersection X refers to a road on which vehicles travel toward the intersection X. The predetermined range is not particularly limited, but may be, for example, a range of approximately 150 to 200 m upstream from the intersection X.

[0018] In this embodiment, each of the first to fourth sensor modules 5A to 5D has a GNSS receiver 51, a road surface detection unit 52, and an object detection unit 53 (see FIG. 1). The GNSS receiver 51 is mainly used to acquire position information and time information. The road surface detection unit 52 includes, for example, a road surface condition sensor, and detects the road surface condition (deformation such as unevenness, dryness, wetness, snow accumulation, freezing, etc.) of the road in the monitoring range. The object detection unit 53 includes, for example, an image sensor (camera), a LiDAR sensor, and an image processing unit, and detects the presence and position of an object (particularly a vehicle) in the monitoring range based on a feature amount, etc. That is, each of the first to fourth sensor modules 5A to 5D can continuously detect the road surface condition of the road in its own monitoring range and the position of each vehicle present in its own monitoring range.

[0019] Each of the first to fourth sensor modules 5A to 5D is configured to output the detection result together with time information periodically, that is, at predetermined time intervals, to the roadside unit 2. In other words, the roadside unit 2 inputs the outputs (detection results) of the first to fourth sensor modules 5A to 5D at the predetermined time intervals. The predetermined time interval is not particularly limited, but is 200 ms in this embodiment.

[0020] Referring to FIG. 2, in this embodiment, the first sensor module 5A is attached to a support arm 42A that supports the first vehicle traffic light 41A. The first sensor module 5A is installed so as to overlook the first road 40A from diagonally above, and monitors the predetermined range of the first road 40A and a part of the intersection X (mainly a part in which the first road 40A is extended into the intersection X). The first road 40A is a road leading to the intersection X, in which the traffic volume and the like are controlled by the first vehicle traffic light 41A, and is located on the opposite side of the intersection X from the first sensor module 5A, and has two vehicle lanes 40A-1 and 40A-2. The first sensor module 5A can detect the presence and position of each vehicle traveling on the first road 40A toward the intersection X, detect the vehicle and its position that has stopped in the intersection X after traveling on the first road 40A, and detect the road surface conditions of the intersection X and the first road 40A. The detection result of the first sensor module 5A is output to the roadside unit 2 at the predetermined time intervals.

[0021] The second sensor module 5B is attached to a support arm 42B that supports the second vehicle traffic light 41B. The second sensor module 5B is installed so as to overlook the second road 40B from diagonally above, and monitors the predetermined range of the second road 40B and a part of the intersection X (mainly a part where the second road 40B is extended into the intersection X). The second road 40B is a road leading to the intersection X, in which the traffic volume and the like are controlled by the second vehicle traffic light 41B, and is located on the opposite side of the intersection X from the second sensor module 5B. The second sensor module 5B can detect the presence and position of a vehicle traveling on the second road 40B toward the intersection X, detect a vehicle and its position that has stopped in the intersection X after traveling on the second road 40B, and detect the road surface conditions of the intersection X and the second road 40B. The detection result of the second sensor module 5B is output to the roadside device 2 at the predetermined time intervals.

[0022] The third sensor module 5C is attached to a support arm 42C that supports the third vehicle traffic light 41C. The third sensor module 5C is installed so as to overlook the third road 40C from diagonally above, and monitors the predetermined range of the third road 40C and a part of the intersection X (mainly a part where the third road 40C is extended into the intersection X). The third road 40C is a road leading to the intersection X, in which the traffic volume and the like are controlled by the third vehicle traffic light 41C, and is located on the opposite side of the intersection X from the third sensor module 5C, and has two vehicle lanes 40C-1 and 40C-2. The third sensor module 5C can detect the presence and position of a vehicle traveling on the third road 40C toward the intersection X, detect the position of a vehicle that has stopped in the intersection X after traveling on the third road 40C, and detect the road surface conditions of the intersection X and the third road 40C. The detection result of the third sensor module 5C is output to the roadside device 2 at the predetermined time intervals.

[0023] The fourth sensor module 5D is attached to a support arm 42D that supports the fourth vehicle traffic light 41D. The fourth sensor module 5D is installed so as to overlook the fourth road 40D from diagonally above, and monitors the predetermined range of the fourth road 40D and a part of the intersection X (mainly a part in which the fourth road 40D is extended into the intersection X). The fourth road 40D is a road leading to the intersection X in which the traffic volume and the like are controlled by the fourth vehicle traffic light 41D, and is located on the opposite side of the intersection X from the fourth sensor module 5D. The fourth sensor module 5D can detect the presence and position of a vehicle traveling on the fourth road 40D toward the intersection X, detect a vehicle and its position that has stopped in the intersection X after traveling on the fourth road 40D, and detect the road surface conditions of the intersection X and the fourth road 40D. The detection result of the fourth sensor module 5D is output to the roadside device 2 at the predetermined time intervals.

[0024] 1, the roadside device communication unit 21 of the roadside device 2 has a communication area including at least the monitoring ranges of the first to fourth sensor modules 5A to 5D centered on the intersection X. In this embodiment, the roadside device communication unit 21 is configured to periodically broadcast a response request and to receive a response from the vehicle-mounted device 3 to the response request.

[0025] The roadside device memory 22 stores information (such as map data) relating to at least the intersection X and the first to fourth roads 40A to 40D. The roadside device memory 22 also has an area reserved for storing various types of information acquired by the roadside device 2.

[0026] When the roadside device communication unit 21 receives a response from the vehicle-mounted device 3 to the response request, the roadside device control unit 23 establishes wireless communication (session) with the vehicle-mounted device 3 that is the source of the response via the roadside device communication unit 21. Here, the vehicle-mounted device 3 that transmits the response to the response request is usually the vehicle-mounted device 3 of the vehicle equipped with the vehicle that has entered the communication area from outside the communication area, that is, the vehicle-mounted device 3 mounted on the vehicle equipped with the vehicle heading toward the intersection X. Therefore, the roadside device control unit 23 can establish the wireless communication (session) with the vehicle equipped with the vehicle (the vehicle-mounted device 3 of the vehicle equipped with the vehicle) heading toward the intersection X, and obtain information on the vehicle equipped with the vehicle equipped with the vehicle heading toward the intersection X through the established wireless communication (session). Note that the information on the vehicle equipped with the vehicle equipped with the vehicle obtained by the roadside device control unit 23 includes the vehicle ID of the vehicle equipped with ...

[0027] Furthermore, the roadside device control unit 23 inputs (acquires) the outputs (detection results) of the first to fourth sensor modules 5A to 5D at predetermined intervals (200 ms) and acquires signal control information at predetermined timing from the signal controller 4. The signal control information includes the timing (time) of switching the light color and the duration of each light color in each of the first to fourth vehicle traffic lights 41A to 41D and the first to fourth pedestrian traffic lights 61A to 61D.

[0028] The roadside unit control unit 23 is configured to appropriately store the acquired information in the roadside unit memory 22 and to execute various processes as described below based on the acquired information (including the information stored in the roadside unit memory 22).

[0029] 1, in this embodiment, the vehicle-mounted device 3, like the roadside device 2, has an in-vehicle communication unit 31 that performs wireless communication with the outside, an in-vehicle memory 32 that stores various information, and an in-vehicle control unit 33 that executes various processes. The vehicle-mounted device 3 is electrically connected to an automatic driving device 6 mounted on the vehicle equipped with the vehicle-mounted device together with itself (i.e., the vehicle-mounted device 3). The automatic driving device 6 is a device that appropriately acquires information required for automatic driving and performs automatic driving of the vehicle equipped with the vehicle-mounted device. The information required for automatic driving includes information acquired from various sensors, information provided by the vehicle-mounted device 3 (acquired via the vehicle-mounted device 3), and the like.

[0030] In this embodiment, the automatic driving device 6 acquires the speed of the vehicle equipped with the on-board device, the acceleration of the vehicle equipped with the on-board device, the position and time information of the vehicle equipped with the on-board device, etc. from a speed sensor, an acceleration sensor, a GNSS receiver, etc. (not shown) mounted on the vehicle equipped with the on-board device. Therefore, the on-board device 3 can acquire the speed, acceleration, position, etc. of the vehicle equipped with the on-board device as the status information of the vehicle equipped with the on-board device from the automatic driving device 6 together with the time information. However, this is not limited to this, and the on-board device 3 may acquire the status information of the vehicle equipped with the on-board device directly from the speed sensor, the acceleration sensor, the GNSS receiver, etc.

[0031] In this embodiment, the automatic driving device 6 is configured to drive the vehicle equipped with the on-board device at a set speed along a preset travel route (including a travel lane; the same applies below). Therefore, the on-board device 3 can obtain the travel route and the set speed of the vehicle equipped with the on-board device from the automatic driving device 6 as route information of the vehicle equipped with the on-board device.

[0032] The vehicle-mounted device 3 (vehicle-mounted device control unit 33) is configured to transmit a response to the response request to the roadside device 2 (roadside device communication unit 21) via the vehicle-mounted device communication unit 31 when the vehicle-mounted device communication unit 31 receives the response request broadcast from the roadside device 2 (roadside device communication unit 21). In this embodiment, the vehicle-mounted device 3 (vehicle-mounted device control unit 33) is configured to transmit information about the vehicle equipped with the vehicle, including time information, to the roadside device 2 (roadside device communication unit 21) when the vehicle-mounted device communication unit 31 receives an information transmission request transmitted from the roadside device 2 (roadside device communication unit 21). The transmitted information about the vehicle equipped with the vehicle includes the vehicle ID of the vehicle equipped with ...

[0033] Next, a description will be given of the processes executed by the roadside device control unit 23 (i.e., the roadside device 2). In this embodiment, the roadside device control unit 23 mainly executes an intersection situation recognition process, an on-board device equipped vehicle recognition process, an identical vehicle determination process, and a driving support information creation / transmission process.

[0034] [Intersection situation understanding processing] The roadside device control unit 23 grasps the situation of the intersection X based on the outputs of the first to fourth sensor modules 5A to 5D. Specifically, in this embodiment, the roadside device control unit 23 grasps the situation of the intersection X by detecting the road surface conditions of the intersection X and the roads leading to the intersection X (detection of road surface conditions), detecting information on each vehicle heading to the intersection X (detection of vehicle information), and predicting the future positions of each vehicle heading to the intersection X (prediction of future positions).

[0035] (Detection of road surface conditions) The road-side device control unit 23 detects road surface conditions such as deformation such as unevenness, dryness, wetness, snow accumulation, and freezing of the intersection X and the roads (first to fourth roads 40A to 40D) leading to the intersection X based on the outputs of the first to fourth sensor modules 5A to 5D.

[0036] (Vehicle information detection) The roadside device control unit 23 detects information on each vehicle heading toward the intersection X based on the outputs of the first to fourth sensor modules 5A to 5D. Specifically, the roadside device control unit 23 detects the current position of each vehicle heading toward the intersection X based on the outputs of the first to fourth sensor modules 5A to 5D, and stores the detected current positions of each vehicle in the roadside device memory 22. The roadside device control unit 23 also calculates (detects) a movement vector (movement speed, movement direction) of each vehicle heading toward the intersection X based on the (latest) current position of each vehicle heading toward the intersection X and the (past) current position of each vehicle heading toward the intersection X detected previously. However, this is not limited to this, and the roadside device control unit 23 may detect (calculate) the movement vector of each vehicle heading toward the intersection X based on the (latest) current position of each vehicle heading toward the intersection X and the past multiple current positions of each vehicle heading toward the intersection X including the current position of each vehicle heading toward the intersection detected previously. That is, in this embodiment, the road-side device control unit 23 detects the current position and movement vector of each vehicle heading toward the intersection X as information about each vehicle heading toward the intersection X.

[0037] (Prediction of future position) The roadside device control unit 23 predicts the future position of each vehicle heading for the intersection X based on the (latest) current position of each vehicle heading for the intersection X detected and the movement vector of each vehicle heading for the intersection X detected (calculated), taking into account the signal control information from the signal controller 4. In this embodiment, the roadside device control unit 23 predicts (calculates) the future position of each vehicle heading for the intersection X up to n seconds ahead (for example, 15 to 20 seconds ahead) in units of the predetermined time (200 ms) starting from the (latest) current position of each vehicle heading for the intersection X. Specifically, the roadside device control unit 23 assumes that each vehicle heading for the intersection X moves straight from its current position to the intersection X, appropriately adjusts the movement speed of each vehicle heading for the intersection X by taking into account the signal control information from the signal controller 4, and then predicts (calculates) the future position of each vehicle heading for the intersection X up to n seconds ahead in units of the predetermined time (200 ms). However, this is not limited to this. The roadside device control unit 23 may predict (calculate) the future position of each vehicle heading towards the intersection X, further taking into account the surface conditions of the intersection X and the road leading to the intersection X.

[0038] Fig. 3 is a flowchart showing an example of an intersection situation grasping process executed by the roadside device control unit 23 (i.e., the roadside device 2). In Fig. 13, in step S1, it is determined whether or not the outputs (detection results) of the first to fourth sensor modules 5A to 5D have been input. Then, when the outputs of the first to fourth sensor modules 5A to 5D have been input, the process proceeds to step S2.

[0039] In step S2, the road surface conditions (such as deformation such as unevenness, dryness, wetness, snow accumulation, and freezing) of the intersection X and the roads (the first to fourth roads 40A to 40D) leading to the intersection X are detected based on the outputs of the first to fourth sensor modules 5A to 5D input in step S1.

[0040] In step S3, the current positions of the vehicles heading toward the intersection X are detected based on the outputs of the first to fourth sensor modules 5A to 5D.

[0041] In step S4, the motion vector (movement speed and movement direction) of each vehicle heading toward the intersection X is detected (calculated). Specifically, the motion vector of each vehicle heading toward the intersection X is detected (calculated) based on the current position of each vehicle heading toward the intersection X detected in step S3 and the (past) current position of each vehicle heading toward the intersection X detected in the previous step S3.

[0042] In step S5, the future position of each vehicle heading for the intersection X is predicted (calculated) based on the current position of each vehicle heading for the intersection X detected in step S3, the movement vector (movement speed, movement direction) of each vehicle heading for the intersection X detected (calculated) in step S4, and the signal control information from the signal controller 4. Specifically, the current position detected in step S3 is used as a starting point, and the future position up to n seconds ahead is predicted (calculated) in units of a predetermined time (200 ms) while adjusting the movement speed based on the signal control information. Note that the future position of each vehicle heading for the intersection X may be predicted (calculated) taking into account the intersection X detected in step S2 and the road surface condition of the road leading to the intersection X. The predicted (calculated) future position of each vehicle heading for the intersection X is stored in the roadside device memory 22. Then, when the process of step S5 is completed, the process returns to step S1.

[0043] Although detailed explanation is omitted here, the information (including future position) of each vehicle stored in the roadside unit memory 22 is cleared, for example, when the corresponding vehicle moves out of the monitoring range of the first to fourth sensor modules 5A to 5D.

[0044] [Vehicle identification processing with on-board device] In this embodiment, the roadside device control unit 23 grasps the vehicle equipped with the in-vehicle unit heading for the intersection X by acquiring information of the vehicle equipped with the in-vehicle unit heading for the intersection X via the wireless communication (session). Specifically, the roadside device control unit 23 periodically (e.g., every 200 ms) transmits the information transmission request to the vehicle equipped with the in-vehicle unit (the in-vehicle unit 3) heading for the intersection X via the roadside device communication unit 21, and receives information of the vehicle equipped with the in-vehicle unit transmitted from the in-vehicle unit 3 of the vehicle equipped with the in-vehicle unit that received the information transmission request. As a result, the roadside device control unit 23 periodically (e.g., every 200 ms) acquires information of the vehicle equipped with the in-vehicle unit heading for the intersection X, i.e., the vehicle ID of the vehicle equipped with the in-vehicle unit, status information of the vehicle equipped with the in-vehicle unit (speed, acceleration, position, etc.) and route information of the vehicle equipped with the in-vehicle unit (travel route, set speed, etc.).

[0045] Further, the roadside device control unit 23 predicts the future position of the vehicle equipped with an on-board unit heading towards the intersection X based on the acquired information of the vehicle equipped with an on-board unit heading towards the intersection X, taking into account the signal control information from the signal controller 4. Specifically, in this embodiment, the roadside device control unit 23 predicts (calculates) the future position of the vehicle equipped with an on-board unit heading towards the intersection X up to the n seconds ahead in the predetermined time unit, as in the case of each vehicle heading towards the intersection X, starting from the current position of the vehicle equipped with an on-board unit heading towards the intersection X, while adjusting the speed based on the signal control information. However, this is not limited to this. The roadside device control unit 23 may predict (calculate) the future position of the vehicle equipped with an on-board unit heading towards the intersection X, further taking into account the road surface conditions of the intersection X and the road leading to the intersection X.

[0046] Fig. 4 is a flowchart showing an example of an on-board unit vehicle recognition process executed by the roadside unit control unit 23 (i.e., the roadside unit 2). This process is executed for each on-board unit vehicle. In Fig. 4, in step S11, it is determined whether or not wireless communication (session) has been established with the on-board unit vehicle (the on-board unit 3) heading toward the intersection X. Then, if the wireless communication (session) has been established, the process proceeds to step S12.

[0047] In step S12, information on the vehicle equipped with an on-board unit heading for the intersection X is acquired by the wireless communication (session), i.e., the vehicle ID, status information (speed, acceleration, position, etc.) and route information (travel route and set speed, etc.) of the vehicle equipped with an on-board unit heading for the intersection X. Specifically, as described above, the information transmission request is transmitted to (the on-board unit 3 of) the vehicle equipped with an on-board unit heading for the intersection X, thereby acquiring information on the vehicle equipped with an on-board unit heading for the intersection X. The acquired information on the vehicle equipped with an on-board unit heading for the intersection X is stored (updated) in the roadside unit memory 22.

[0048] In step S13, the future position of the vehicle equipped with an on-board unit heading towards the intersection X is predicted (calculated) based on the information of the vehicle equipped with an on-board unit acquired in step S12 and the signal control information from the signal controller 4. Specifically, the future position of the vehicle equipped with an on-board unit heading towards the intersection X is predicted (calculated) up to the n seconds ahead in units of a predetermined time (200 ms). The predicted (calculated) future position of the vehicle equipped with an on-board unit heading towards the intersection X is stored in the roadside unit memory 22. Then, when the processing of step S13 ends, the process returns to step S11.

[0049] Although detailed explanation is omitted here, the information (including future position) of the vehicle equipped with the on-board unit stored in the roadside unit memory 22 is cleared, for example, when the vehicle equipped with the on-board unit moves outside the communication area of ​​the roadside unit 2 (its roadside unit communication unit 21).

[0050] [Identical vehicle determination process] As described above, in this embodiment, the roadside device control unit 23 detects (calculates) information on each vehicle heading to the intersection X based on the outputs of the first to fourth sensor modules 5A to 5D (intersection situation grasping process). In addition, the roadside device control unit 23 acquires information on the vehicle equipped vehicle heading to the intersection X by the wireless communication (session) (vehicle equipped vehicle grasping process). Here, the vehicle equipped vehicle heading to the intersection X is nothing but a vehicle heading to the intersection X. Therefore, the roadside device control unit 23 acquires information on one vehicle equipped vehicle twice (duplicately), and as a result, there is a risk of erroneously grasping the situation of the intersection X (mistaking one vehicle equipped with an in-vehicle device for two vehicles). In addition, as described later, in this embodiment, when the roadside device control unit 23 determines whether or not there is a possibility of a contact accident between the vehicle equipped with an in-vehicle device and another vehicle, if the roadside device control unit 23 misidentifies one vehicle equipped with an in-vehicle device as two vehicles (the vehicle equipped with an in-vehicle device and the other vehicle), there is a risk of determining (i.e., erroneously determining) that the two vehicles will contact each other.

[0051] To eliminate such a concern, in this embodiment, the roadside device control unit 23 executes an identical vehicle determination process to determine that any one of the vehicles heading toward the intersection X is the same vehicle as the vehicle equipped with the in-vehicle unit, thereby preventing one vehicle equipped with the in-vehicle unit from being mistaken for two vehicles. Specifically, the roadside device control unit 23 determines that any one of the vehicles heading toward the intersection X is the same vehicle as the vehicle equipped with the in-vehicle unit in the following manner.

[0052] The roadside device control unit 23 compares the information of the vehicle equipped with the in-vehicle device heading for the intersection X acquired through the wireless communication (session) (see step S12 in FIG. 14) with the information of each vehicle equipped with the in-vehicle device heading for the intersection X detected based on the output of the first to fourth sensor modules 5A to 5D (see steps S3 and S4 in FIG. 13). This comparison is performed for each vehicle equipped with the in-vehicle device. Then, the roadside device control unit 23 extracts from each vehicle a vehicle whose current position is closest (approximately the same) to the position of the vehicle equipped with the in-vehicle device and whose moving direction is along the moving path of the vehicle equipped with the in-vehicle device, and determines that the extracted vehicle is the same vehicle as the vehicle equipped with the in-vehicle device. As a result, the roadside device control unit 23 recognizes (treats) the extracted vehicle and the vehicle equipped with the in-vehicle device as the same vehicle (vehicle equipped vehicle), eliminating the above-mentioned concern.

[0053] [Driving assistance information creation / transmission processing] In this embodiment, the roadside device control unit 23 creates corresponding signal information as driving assistance information and transmits it by wireless communication to the vehicle equipped with the on-board unit heading toward the intersection X. The corresponding signal information is signal control information related to a traffic light that the vehicle equipped with the on-board unit heading toward the intersection X should follow. For example, when the vehicle equipped with the on-board unit is traveling on the first road 40A (vehicle lane 40A-1 or 40A-2), the corresponding signal information is signal control information related to the first vehicle traffic light 41A, and when the vehicle equipped with the on-board unit is traveling on the fourth road 40D, the corresponding signal information is signal control information related to the fourth vehicle traffic light 41D.

[0054] Furthermore, in this embodiment, the roadside unit control unit 23 executes a contact determination process to determine whether or not there is a possibility of a contact accident (including a collision accident; the same applies below) between the vehicle equipped with the on-board unit and another vehicle, and if it is determined that there is a possibility of the contact accident, creates driving assistance information to avoid the contact accident or information to reduce damage caused by the contact accident, and transmits the information to the vehicle equipped with the on-board unit via wireless communication.

[0055] The roadside unit control unit 23 basically compares the predicted future position of the vehicle equipped with an onboard unit heading toward the intersection X with the predicted future positions of each vehicle heading toward the intersection X, and if there is a vehicle among the vehicles heading toward the intersection X that is predicted to be located at approximately the same position as the vehicle equipped with an onboard unit at the same time (in other words, within the same position range set as a range that can be considered to be the same position), it determines that there is a possibility of a collision accident between the vehicle equipped with an onboard unit and another vehicle.

[0056] Here, a collision accident between an on-board unit vehicle and another vehicle is particularly likely to occur when the on-board unit vehicle travels across an oncoming road portion within an intersection X, i.e., when the on-board unit vehicle turns right at the intersection X. Hereinafter, a collision determination process will be specifically described for a case where the on-board unit vehicle V1 travels across an oncoming road portion XC within the intersection X (turns right at the intersection X). Note that, although a case where the on-board unit vehicle V1 is traveling or has traveled on the first road 40A will be described here, the same applies to an on-board unit vehicle traveling or has traveled on the second road 40B, the third road 40C, or the fourth road 40D.

[0057] FIG. 5 is a diagram for explaining a contact determination process (hereinafter referred to as "first contact determination process") for an on-board unit vehicle heading toward an intersection X. In FIG. 5, an on-board unit vehicle V1 traveling on a first road 40A (vehicle lane 40A-2) toward the intersection X is about to turn right at the intersection X. That is, the on-board unit vehicle V1 is about to cross an oncoming road portion XC in the intersection X. In this case, the future position of the on-board unit vehicle is predicted on the arrow indicated by a dashed line in the figure. The on-coming road portion XC in the intersection X refers to a road portion in the intersection X where a vehicle travels in the opposite direction to the on-board unit vehicle V1 in the intersection X and where the on-board unit vehicle V1 enters when turning right. In this case, the on-board unit vehicle V1 is an extension of a third road 40C (vehicle lane 40C-1) corresponding to an on-coming road of the first road 40A (vehicle lane 40A-2) on which the on-board unit vehicle V1 is traveling, into the intersection X.

[0058] In this case, the roadside unit control unit 23 determines whether or not there is a risk of contact (including collision; the same applies below) with another vehicle when the vehicle V1 equipped with the onboard unit turns right at the intersection X, specifically, determines the possibility of a contact accident between the vehicle V1 equipped with the onboard unit traveling on the first road 40A (its vehicle lane 40A-2) and the vehicle VO traveling on the third road 40C (its vehicle lane 40C-1), which corresponds to the oncoming road of the first road 40A (its vehicle lane 40A-2).

[0059] In this embodiment, the roadside device control unit 23 predicts the time when the on-board device vehicle V1 reaches a right turn start position Xs (corresponding to the future position of the on-board device vehicle V1) at the intersection X and the time when the on-board device vehicle V1 passes through a right turn end position Xe (corresponding to the future position of the on-board device vehicle V1) at the intersection X (exits the intersection X) based on the information of the on-board device vehicle V1 and the signal control information from the signal controller 4. That is, the roadside device control unit 23 predicts the time when the on-board device vehicle V1 starts to turn right at the intersection X (hereinafter referred to as the "intersection right turn start time") and the time when the on-board device vehicle V1 finishes turning right at the intersection X (hereinafter referred to as the "intersection right turn end time"). This prediction is performed every time the roadside device control unit 23 acquires information of the on-board device vehicle V1, and the intersection right turn start time and the intersection right turn end time are updated.

[0060] In addition, the roadside unit control unit 23 checks the predicted future position of each vehicle heading toward the intersection X, in particular, the predicted future position of the vehicle VO traveling toward the intersection X on the third road 40C (the vehicle lane 40C-1), which corresponds to the oncoming road of the first road 40A (the vehicle lane 40A-2) on which the vehicle V1 equipped with the onboard unit is traveling.

[0061] Then, if there is a vehicle VO that is predicted to be located in the oncoming road portion XC between the intersection right turn start time and the intersection right turn end time, the roadside unit control unit 23 determines that there is a possibility of a contact accident between the vehicle V1 equipped with the onboard unit and another vehicle (here, vehicle VO).

[0062] Here, the roadside device control unit 23 may adjust the intersection right turn start time and / or the intersection right turn end time by taking into consideration the road surface condition of the target road corresponding to the vehicle V1, which changes the vehicle speed and the braking distance depending on the road surface condition. The target road corresponding to the vehicle V1 refers to at least one of the first road 40A (particularly the vehicle lane 40A-2) on which the vehicle V1 is traveling, the road in the intersection X, and the third road 40C corresponding to the oncoming road of the first road 40A (the vehicle travels in the opposite direction to the vehicle V1). For example, when the road surface condition of the target road is wet, the roadside device control unit 23 can adjust the intersection right turn end time to be later than when the road surface condition of the target road is dry, and can adjust the intersection right turn end time to be further later when the road surface condition of the target road is snowy or icy.

[0063] When the roadside unit control unit 23 determines that there is a possibility of a collision accident between the vehicle V1 equipped with an on-board unit and another vehicle, it creates driving assistance information, such as information for avoiding the collision accident or information for reducing damage caused by the collision accident, depending on the risk of the collision accident, and transmits the created driving assistance information to the vehicle V1 equipped with an on-board unit (the on-board unit 3).

[0064] For example, if the vehicle V1 equipped with an onboard unit is likely to collide with another vehicle (here, vehicle VO) if it continues traveling at the current speed, but the vehicle V1 equipped with an onboard unit can avoid a collision accident with the other vehicle (vehicle VO) by decelerating at about 0.2 G (in other words, if the vehicle V1 equipped with an onboard unit can stop by the right turn start position Xs), the roadside unit control unit 23 creates driving assistance information (hereinafter referred to as "first driving assistance information") instructing the vehicle V1 to perform normal deceleration and transmits it to the vehicle V1 equipped with an onboard unit.

[0065] In addition, if there is a high possibility that the vehicle V1 equipped with an onboard unit will come into contact with another vehicle (vehicle VO) if it continues traveling at the current speed, but if the vehicle V1 equipped with an onboard unit can avoid a collision accident with the other vehicle (vehicle VO) by decelerating at about 0.3 G, the roadside unit control unit 23 creates driving assistance information (hereinafter referred to as "second driving assistance information") instructing the vehicle V1 to decelerate more strongly and transmits it to the vehicle V1 equipped with an onboard unit.

[0066] Furthermore, if there is a high possibility that the vehicle V1 equipped with an onboard unit will come into contact with another vehicle (vehicle VO) if it continues traveling at the current speed, but if the vehicle V1 equipped with an onboard unit can avoid a collision accident with the other vehicle (vehicle VO) by decelerating at 0.5G, the roadside unit control unit 23 creates driving assistance information (hereinafter referred to as "third driving assistance information") instructing the vehicle V1 to rapidly decelerate, and transmits it to the vehicle V1 equipped with an onboard unit.

[0067] Furthermore, if there is a high possibility that a collision accident with another vehicle (vehicle VO) cannot be avoided even if the vehicle V1 equipped with the onboard unit decelerates at 0.5G, the roadside unit control unit 23 creates driving assistance information (hereinafter referred to as "fourth driving assistance information") instructing the vehicle V1 to decelerate to the maximum extent possible in order to reduce damage caused by a collision accident with another vehicle (vehicle VO) and transmits the information to the vehicle V1 equipped with the onboard unit.

[0068] 6 is a flowchart showing an example of a first contact determination process (including a driving support information creation / transmission process) for a vehicle equipped with an on-board unit heading toward an intersection X. This flowchart is started, for example, when wireless communication (session) is established between the roadside unit 2 and the on-board unit 3 of the on-board unit vehicle V1.

[0069] In FIG. 6, in step S21, information on the vehicle V1 equipped with the in-vehicle device, that is, status information (speed, acceleration, position, etc.) and route information (travel route, set speed, etc.) of the vehicle V1 equipped with the in-vehicle device are acquired.

[0070] In step S22, it is determined whether or not the vehicle V1 is about to turn right at the intersection X based on the information (particularly the travel route) of the vehicle V1 acquired in step S21. If the vehicle V1 is about to turn right at the intersection X, the process proceeds to step S23. On the other hand, if the vehicle V1 is not about to turn right at the intersection X or if the vehicle V1 has completed turning right at the intersection X, the process ends.

[0071] In step S23, it is determined whether or not there is a possibility that the vehicle V1 equipped with the on-board unit will come into contact with another vehicle when the vehicle V1 makes a right turn, that is, whether or not there is a possibility of a contact accident between the vehicle V1 equipped with the on-board unit and another vehicle. Specifically, the roadside device control unit 23 predicts the intersection right turn start time and intersection right turn end time of the vehicle V1 equipped with the on-board unit based on the information of the vehicle V1 equipped with the on-board unit acquired in step S21 and the signal control information from the signal control unit 4. In addition, the roadside device control unit 23 checks the predicted future positions of each vehicle heading toward the intersection X (particularly, the vehicle VO traveling toward the intersection X on the third road 40C). Then, if there is a vehicle VO that is predicted to be located in the oncoming road portion XC between the intersection right turn start time and the intersection right turn end time, the roadside device control unit 23 determines that there is a possibility of a contact accident between the vehicle V1 equipped with the on-board unit and another vehicle. If it is determined that there is a possibility of a collision accident between the vehicle V1 equipped with the on-board unit and another vehicle, the process proceeds to step S24, and if it is determined that there is no possibility of a collision accident between the vehicle V1 equipped with the on-board unit and another vehicle, the process returns to step S21.

[0072] In step S24, driving support information is created to avoid a collision between the vehicle V1 equipped with the on-board device and another vehicle or to reduce damage caused by a collision between the vehicle V1 equipped with the on-board device and another vehicle. The created driving support information is any one of the first to fourth driving support information.

[0073] In step S25, the driving assistance information created in step S24 is transmitted to the vehicle V1 equipped with the on-board device. Then, when the process of step S25 ends, the process returns to step S21.

[0074] FIG. 7 is a diagram for explaining the contact determination process (hereinafter referred to as "second contact determination process") for an on-board unit equipped vehicle waiting to turn right at an intersection X. In FIG. 7, the on-board unit equipped vehicle V1, which has been traveling on the first road 40A (the vehicle lane 40A-2 of the first road 40A), is waiting at the intersection X to turn right at the intersection X. In other words, the on-board unit equipped vehicle V1 is stopped at the right turn start position Xs at the intersection X. In this case, the future position of the on-board unit equipped vehicle is predicted on the arrow indicated by the dashed line in the figure.

[0075] In this case, the roadside device control unit 23 calculates the time required for the vehicle V1 equipped with the on-board device to pass the right turn end position Xe (to exit the intersection X) when starting from the right turn start position Xs with a standard acceleration (hereinafter referred to as the "intersection passing time"). The calculated intersection passing time varies depending on factors such as the size of the intersection X, but is generally 6 to 10 seconds. Note that the roadside device control unit 23 may use a preset intersection passing time instead of calculating the intersection passing time.

[0076] In addition, the roadside unit control unit 23 checks the predicted future position of each vehicle heading toward the intersection X, in particular, the predicted future position of the vehicle VO traveling toward the intersection X on the third road 40C (the vehicle lane 40C-1), which corresponds to the oncoming road of the first road 40A (the vehicle lane 40A-2) on which the vehicle V1 equipped with the onboard unit is traveling.

[0077] Then, the roadside unit control unit 23 determines that there is a possibility of a collision accident between the vehicle V1 equipped with an onboard unit and another vehicle if there is a vehicle VO that is predicted to be located within the oncoming road section XC between the current time and the time when the vehicle V1 equipped with an onboard unit enters the intersection, which is the current time plus the time required to pass through the intersection.

[0078] Here, the roadside unit control unit 23 may take into consideration that the acceleration of the vehicle V1 equipped with an on-board unit varies depending on the road surface condition, and adjust the intersection required passage time and therefore the intersection passage time by taking into account the road surface condition of the target road corresponding to the vehicle V1 equipped with an on-board unit, particularly the road within the intersection X. For example, the roadside unit control unit 23 may adjust the intersection required passage time to be longer (the intersection passage time to be later) when the road surface condition of the target road is wet compared to when the road surface condition of the target road is dry.

[0079] When the roadside unit control unit 23 determines that there is a possibility of a collision accident between the vehicle V1 equipped with an on-board unit and another vehicle, it creates driving assistance information instructing the vehicle V1 to continue waiting to turn right (instructing the vehicle to prohibit starting) in order to avoid the collision accident, and transmits the information to the vehicle V1 equipped with an on-board unit (the on-board unit 3). On the other hand, when the roadside unit control unit 23 determines that there is no possibility of a collision accident between the vehicle V1 equipped with an on-board unit and another vehicle, it creates driving assistance information permitting a right turn (starting), and transmits the information to the vehicle V1 equipped with an on-board unit (the on-board unit 3).

[0080] 8 is a flowchart showing an example of a second contact determination process (including a driving support information creation / transmission process) for an on-board unit equipped vehicle waiting to turn right at an intersection X. This process is started, for example, when it is confirmed that the on-board unit equipped vehicle V1 has started waiting to turn right at the intersection X (when it is confirmed that the vehicle has stopped at the right turn start position Xs).

[0081] In FIG. 8, in step S31, the intersection passing time of the vehicle V1 equipped with the on-board unit, that is, the time required for the vehicle V1 equipped with the on-board unit to pass the right turn end position Xe (to exit the intersection X) after starting from the right turn start position Xs, is calculated.

[0082] In step S32, the intersection exit time of the vehicle V1 equipped with the on-board device is calculated by adding the intersection passing time calculated in step S31 to the current time.

[0083] In step S33, it is determined whether or not there is a possibility that the vehicle V1 equipped with the on-board unit will come into contact with another vehicle when the vehicle V1 equipped with the on-board unit starts, that is, whether or not there is a possibility of a collision accident between the vehicle V1 equipped with the on-board unit and another vehicle. Specifically, the roadside device control unit 23 checks the predicted future positions of each vehicle heading toward the intersection X (particularly, the vehicle VO traveling on the third road 40C toward the intersection X). Then, when there is a vehicle VO that is predicted to be located in the oncoming road portion XC between the current time and the intersection exit time calculated in step S32, the roadside device control unit 23 determines that there is a possibility of a collision accident between the vehicle V1 equipped with the on-board unit and another vehicle. If it is determined that there is a possibility of a collision accident between the vehicle V1 equipped with the on-board unit and another vehicle, the process proceeds to step S34, and if it is determined that there is no possibility of a collision accident between the vehicle V1 equipped with the on-board unit and another vehicle, the process proceeds to step S36.

[0084] In step S34, driving support information instructing the driver to continue waiting for a right turn is created, and in step S35, the driving support information created in step S34 is transmitted to the vehicle V1 (the on-board device 3 of the on-board device). Then, when the process of step S35 ends, the process returns to step S32.

[0085] In step S36, driving assistance information for permitting a right turn (start) is created, and in step S37, the driving assistance information created in step S36 is transmitted to the vehicle V1 (the on-board device 3 of the on-board device). Then, when the process of step S37 ends, this flowchart ends.

[0086] In the intersection driving assistance system 1 according to the embodiment, the roadside device 2 acquires information of the on-board device-equipped vehicle heading for the intersection X by wireless communication, detects information of each vehicle heading for the intersection X based on the output (detection results) of the first to fourth sensor modules 5A to 5D, determines that one of the vehicles is the same vehicle as the on-board device-equipped vehicle based on the acquired information of the on-board device-equipped vehicle and the detected information of each vehicle, and transmits driving assistance information obtained based on the acquired information of the on-board device-equipped vehicle and the detected information of each vehicle to the on-board device-equipped vehicle. Therefore, according to the roadside device 2 in the present embodiment, it is possible to identify the on-board device-equipped vehicle from among the vehicles heading for the intersection X, and provide individual driving assistance information to the on-board device-equipped vehicle.

[0087] Here, the information on the vehicle equipped with the on-board unit includes status information (speed, acceleration, position, etc.) of the vehicle equipped with the on-board unit and route information (movement route and set speed, etc.) of the vehicle equipped with the on-board unit, and the information on each vehicle includes the movement vector (movement speed and movement direction) of each vehicle and the position (current position) of each vehicle. Therefore, the roadside unit 2 can easily and accurately determine that the vehicle is the same as the vehicle equipped with the on-board unit among the vehicles heading toward the intersection X. For example, the roadside unit 2 can extract, from among the vehicles, a vehicle whose position (current position) approximately matches the position of the vehicle equipped with the on-board unit and whose movement direction is along the movement route of the vehicle equipped with the on-board unit, and determine that the extracted vehicle is the same as the vehicle equipped with the on-board unit.

[0088] Furthermore, the roadside unit 2 determines whether there is a possibility of a future collision accident between the vehicle equipped with the on-board unit and other vehicles based on the information of the vehicle equipped with the on-board unit and the information of each vehicle, and if it determines that there is a possibility of the collision accident, transmits information for avoiding the collision accident or information for reducing damage caused by the collision accident to the vehicle equipped with the on-board unit as the driving support information. Therefore, it is possible to significantly reduce the occurrence of collision accidents between the vehicle equipped with the on-board unit and other vehicles at intersection X, and even if a collision accident between the vehicle equipped with the on-board unit and other vehicles does occur, it is possible to significantly reduce the damage.

[0089] Although the embodiment of the present invention has been described above, the present invention is not limited to the above-mentioned embodiment, and it is needless to say that modifications and changes can be made based on the technical concept of the present invention. [Explanation of symbols]

[0090] Reference Signs List 1... intersection driving assistance system, 2... roadside unit, 3... vehicle-mounted unit, 4... traffic light controller, 5A-5D... first to fourth sensor modules, 6... automatic driving device, 21... roadside unit communication unit, 22... roadside unit memory, 23... roadside unit control unit, 31... vehicle-mounted unit communication unit, 32... vehicle-mounted unit memory, 33... vehicle-mounted unit control unit, 40A-40D... first to fourth roads, 41A-41D... first to fourth vehicle traffic lights, V1... vehicle equipped with vehicle-mounted unit, VO... vehicle, X... intersection, XC... oncoming road portion, Xe... right turn end position, Xs... right turn start position

Claims

1. 1. A roadside unit that acquires signal control information of traffic lights installed at an intersection, acquires information of vehicles equipped with an on-board unit heading towards the intersection via wireless communication, detects information of each vehicle heading towards the intersection based on the output of a sensor module, determines that one of the vehicles is the same vehicle as the on-board unit vehicle based on the information of the vehicle equipped with an on-board unit and the information of each vehicle, predicts a future position of the vehicle equipped with an on-board unit taking into account the signal control information based on the information of the vehicle equipped with an on-board unit, predicts a future position of each of the vehicles taking into account the signal control information based on the information of the vehicle equipped with an on-board unit, and transmits driving assistance information obtained by comparing the predicted future position of the vehicle equipped with an on-board unit with the predicted future positions of each of the vehicles to the on-board unit vehicle.

2. The roadside unit according to claim 1 , wherein the roadside unit is integrated with a traffic light controller that controls the traffic light.

3. The information on the vehicle equipped with the on-board device includes a position, a speed, and a moving route of the vehicle equipped with the on-board device, The information of each vehicle includes a current position and a movement vector of each vehicle. The roadside unit according to claim 1 .

4. The roadside unit according to claim 3, wherein among the vehicles, a vehicle whose current position is closest to the position of the vehicle equipped with the vehicle-mounted unit and whose moving direction is along the moving path of the vehicle equipped with the vehicle-mounted unit is determined to be the same vehicle as the vehicle equipped with the vehicle-mounted unit.

5. A roadside unit as described in claim 4, which determines whether or not there is a possibility of a collision accident between the vehicle equipped with the onboard unit and other vehicles based on a comparison between a predicted future position of the vehicle equipped with the onboard unit and the predicted future positions of each of the vehicles, and if it determines that there is a possibility of the collision accident, transmits information for avoiding the collision accident or information for reducing damage caused by the collision accident to the vehicle equipped with the onboard unit as the driving assistance information.

6. 6. The roadside unit according to claim 5, wherein the roadside unit determines that there is a possibility of the collision accident when there is a vehicle among the vehicles that is predicted to be located at approximately the same position as the vehicle equipped with the on-board unit at the same time.

7. 7. The roadside device according to claim 5, further comprising: a road surface condition of a road leading to the intersection detected from an output of the sensor module; and a road surface condition of the road leading to the intersection detected from an output of the sensor module;

8. 8. The roadside device according to claim 1, wherein the vehicle equipped with the on-board device is an autonomous vehicle.

Images