Collision avoidance assistance system and collision avoidance assistance device

Abstract

The present application provides a collision avoidance assistance system and a collision avoidance assistance device. A collision avoidance assistance device (10) of a first vehicle of a collision avoidance assistance system (100) emits a first wireless signal indicating position information and speed information of the first vehicle. A collision avoidance assistance device of a second vehicle of the collision avoidance assistance system acquires the position information and speed information of the first vehicle based on the first wireless signal upon reception of the first wireless signal, and emits a second wireless signal indicating collision information in a case where it is determined based on the position information and speed information and position information and speed information of the first vehicle acquired by a peripheral information sensor device (70) of the second vehicle that the first vehicle and the second vehicle are likely to collide. The collision avoidance assistance device of the first vehicle implements a collision avoidance process for the first vehicle upon reception of the second wireless signal.

Description

TECHNICAL FIELD

[0001] The present application relates to a collision avoidance assistance system and a collision avoidance assistance device. BACKGROUND

[0002] There is known a technology of performing wireless communication (inter-vehicle communication) between two vehicles, each vehicle (own vehicle) acquiring information of a vehicle of an object side (vehicle of an object side) through the inter-vehicle communication, and using the acquired information of the vehicle of the object side for driving assistance of the own vehicle (for example, refer to Patent Literature 1).

[0003] Further, there is also known a collision avoidance assistance device configured to implement a collision avoidance process (for example, a process of braking a vehicle) for avoiding a collision between a vehicle traveling on a road of one side toward an intersection of two roads and a vehicle traveling on a road of the other side toward the intersection of the two roads (for example, refer to Patent Literature 1).

[0004] PRIOR ART DOCUMENTS

[0005] PATENT LITERATURE

[0006] Patent Literature 1: Japanese Patent Application Laid-Open No. 2015-97028

[0007] In the above-described collision avoidance assistance device, if it is not possible to determine a possibility of a collision (collision possibility) between a vehicle traveling on a road of one side toward an intersection of two roads and a vehicle traveling on a road of the other side toward the intersection of the two roads with high accuracy, the start of the collision avoidance process in each vehicle can be late, or conversely, can be early. If the start of the collision avoidance process is late, it is not possible to avoid a collision between the vehicles, and further, if the start of the collision avoidance process is early, unnecessary collision avoidance process is implemented. Therefore, in order to avoid the implementation of unnecessary collision avoidance process, and in order to avoid a collision between the vehicles, it is necessary to determine the collision possibility with high accuracy, and therefore it is necessary to acquire position information and speed information of the own vehicle with high accuracy, and it is necessary to acquire position information and speed information of the vehicle of the object side with high accuracy.

[0008] In a case where the own vehicle is equipped with a peripheral information sensor device such as a camera, a radar sensor, and the like, it is possible to use position information and speed information of the vehicle of the object side acquired using the peripheral information sensor device for the determination of the above-described collision possibility. However, in a scenario where two vehicles are traveling on respective roads toward an intersection, it is difficult to acquire position information and speed information of the vehicle of the object side with high accuracy based on information (autonomous sensor information) provided from the peripheral information sensor device of the own vehicle.

[0009] Therefore, it is considered to acquire the position information and the speed information of the subject vehicle through the inter-vehicle communication with the subject vehicle, and to determine the collision possibility using the position information and the speed information. However, there is a communication delay in the general inter-vehicle communication, and thus the simultaneity of the information of the inter-vehicle communication (i.e., the consistency of the value indicated by the information at the time when the information is acquired through the inter-vehicle communication and the actual value at the time point of the acquisition of the information) is low. Therefore, it is difficult to acquire the position information and the speed information of the subject vehicle with high precision based on the information acquired through the inter-vehicle communication with the subject vehicle (inter-vehicle communication information). SUMMARY

[0010] An object of the present application is to provide a collision avoidance assistance system and a collision avoidance assistance device that can avoid the implementation of unnecessary collision avoidance assistance and can more reliably avoid the collision of vehicles with each other in a scenario in which the vehicles are traveling toward a crossing on respective roads.

[0011] The collision avoidance assistance system of the present application includes a collision avoidance assistance device that is a first vehicle and that can transmit a wireless signal to the outside of the first vehicle, and a collision avoidance assistance device that is a second vehicle and that can receive the wireless signal transmitted to the outside of the first vehicle and can transmit a wireless signal to the outside of the second vehicle. Also, the collision avoidance assistance system of the present application is a system that avoids the collision of the first vehicle and the second vehicle.

[0012] The collision avoidance assistance device of the first vehicle transmits a first wireless signal to the outside of the first vehicle, wherein the first wireless signal indicates position information and speed information of the first vehicle and indicates identification information, and the identification information indicated by the first wireless signal indicates that the first wireless signal is a signal transmitted from the first vehicle.

[0013] The collision avoidance assistance device of the second vehicle acquires the position information and the speed information of the first vehicle based on the first wireless signal in a case where the first wireless signal is received, and transmits a second wireless signal to the outside of the second vehicle in a case where it is determined based on the acquired position information and speed information of the first vehicle and the position information and the speed information of the first vehicle acquired by a surrounding information sensor device mounted on the second vehicle that the first vehicle and the second vehicle can collide, wherein the second wireless signal indicates collision information indicating that the first vehicle and the second vehicle can collide and indicates identification information, and the identification information indicated by the second wireless signal indicates that the second wireless signal is a signal to the first vehicle.

[0014] And, the collision avoidance assistance device of the second vehicle acquires the position information and the speed information of the first vehicle based on the wireless signal emitted from the collision avoidance assistance device of the first vehicle. In other words, the collision avoidance assistance device of the second vehicle acquires the position information and the speed information of the first vehicle based on the information (inter-vehicle communication information) provided by the collision avoidance assistance device of the first vehicle in the wireless signal.

[0015] According to the collision avoidance assistance system of the present application, the collision avoidance assistance device of the second vehicle acquires the position information and the speed information of the first vehicle based on the wireless signal emitted from the collision avoidance assistance device of the first vehicle. In other words, the collision avoidance assistance device of the second vehicle acquires the position information and the speed information of the first vehicle based on the information (inter-vehicle communication information) provided by the collision avoidance assistance device of the first vehicle in the wireless signal.

[0016] And, the collision avoidance assistance device of the second vehicle acquires the position information and the speed information of the first vehicle by the periphery information sensor device of the second vehicle. In other words, the collision avoidance assistance device of the second vehicle acquires the position information and the speed information of the first vehicle based on the information (autonomous sensor information) provided by the periphery information sensor device of the second vehicle.

[0017] And, the collision avoidance assistance device of the second vehicle combines the inter-vehicle communication information and the autonomous sensor information to judge the possibility of collision (collision possibility) of the first vehicle and the second vehicle.

[0018] As described above, in order to judge the collision possibility of the vehicle traveling on the road on one side toward the intersection of two roads and the vehicle traveling on the road on the other side toward the intersection of two roads with high precision, it is necessary to acquire the position information and the speed information of the vehicle on the other side with high precision in addition to acquiring the position information and the speed information of the vehicle on one side with high precision. That is, in order to judge the collision possibility of the first vehicle traveling on the road on one side toward the intersection of two roads and the second vehicle traveling on the road on the other side toward the intersection of two roads with high precision, it is necessary to acquire the position information and the speed information of the second vehicle with high precision in addition to acquiring the position information and the speed information of the first vehicle with high precision.

[0019] The simultaneity of the information of the autonomous sensor information (i.e., the consistency of the value indicated by the information at the time of acquisition of the information and the actual value at the point of time of acquisition of the information) is higher than that of the information of the inter-vehicle communication information. Therefore, acquiring the position information and the speed information of the first vehicle based on the autonomous sensor information enables to acquire the position information and the speed information with higher simultaneity than acquiring the position information and the speed information of the first vehicle based on the inter-vehicle communication information.

[0020] However, in a case where the first vehicle and the second vehicle are traveling in a front-rear relationship in a traveling direction, the collision avoidance assist device of the vehicle at the rear (the second vehicle) can acquire position information and speed information of the vehicle at the front (the first vehicle) with high precision on the basis of autonomous sensor information, but in a scenario in which the first vehicle is traveling on one road toward an intersection at which two roads intersect and the second vehicle is traveling on the other road toward the intersection, it is difficult to acquire position information and speed information of the first vehicle with high precision on the basis of autonomous sensor information. That is, while there is an advantage in acquisition of position information and speed information of the first vehicle on the basis of autonomous sensor information in that simultaneity of information is high, there is a disadvantage in that it is difficult to acquire position information and speed information with high precision.

[0021] On the other hand, since the inter-vehicle communication information is information emitted by the collision avoidance assist device of the first vehicle, position information and speed information of the first vehicle acquired on the basis of the inter-vehicle communication information are themselves highly precise, but, as described above, simultaneity of the inter-vehicle communication information is low. That is, while there is an advantage in acquisition of position information and speed information of the first vehicle on the basis of the inter-vehicle communication information in that position information and speed information can be acquired with high precision, there is a disadvantage in that simultaneity of information is low.

[0022] Further, in a case where the first vehicle and the second vehicle are traveling in a front-rear relationship in a traveling direction, the collision avoidance assist device of the vehicle at the rear (the second vehicle) can always acquire autonomous sensor information related to the first vehicle, but in a scenario in which the first vehicle is traveling on one road toward an intersection at which two roads intersect and the second vehicle is traveling on the other road toward the intersection, there are cases in which autonomous sensor information related to the first vehicle cannot be acquired due to the first vehicle being hidden from the second vehicle behind an object or the like. Such a disadvantage also exists in acquisition of position information and speed information of the first vehicle on the basis of autonomous sensor information.

[0023] In this regard, even in a scenario in which the collision avoidance assist device of the second vehicle cannot acquire autonomous sensor information related to the first vehicle due to the first vehicle being hidden from the second vehicle or the like, the collision avoidance assist device of the second vehicle can acquire position information and speed information of the first vehicle on the basis of inter-vehicle communication information.

[0024] According to the collision avoidance assistance system of the present application, the collision avoidance assistance device of the second vehicle combines the inter-vehicle communication information and the autonomous sensor information to determine the collision possibility of the first vehicle and the second vehicle. Therefore, the drawbacks of acquisition of the position information and the speed information of the first vehicle based on the inter-vehicle communication information and the autonomous sensor information are complementary, and as a result, the collision possibility can be determined with high precision. Therefore, in such a scenario where the vehicles are traveling on respective roads toward an intersection, implementation of unnecessary collision avoidance processing can be avoided, and collision of the vehicles with each other can be more reliably avoided.

[0025] Note that, in the collision avoidance assistance system of the present application, the collision avoidance assistance device of the second vehicle can also be configured to implement, in a case where it is determined that the first vehicle and the second vehicle are likely to collide, collision avoidance processing for avoiding collision of the first vehicle and the second vehicle for the second vehicle.

[0026] Accordingly, in addition to implementing collision avoidance processing for the first vehicle, collision avoidance processing is also implemented for the second vehicle, and therefore collision of the first vehicle and the second vehicle can be more reliably avoided.

[0027] Further, in the collision avoidance assistance system of the present application, the position information is, for example, information acquired based on a GPS signal.

[0028] The GPS signal provides position information of a vehicle in a unified coordinate system. Therefore, by acquiring the position information of the first vehicle based on the GPS signal, the position information of the first vehicle can be acquired with high precision.

[0029] Further, in the collision avoidance assistance system of the present application, the speed information is, for example, information acquired based on a GPS signal.

[0030] The GPS signal provides speed information of a vehicle in a unified coordinate system. Therefore, by acquiring the speed information of the first vehicle based on the GPS signal, the speed information of the first vehicle can be acquired with high precision.

[0031] Further, in the collision avoidance assistance system of the present application, the speed information is, for example, a relative speed vector of the first vehicle and the second vehicle.

[0032] In order to determine the collision possibility of vehicles traveling on respective roads toward an intersection where the two roads intersect with high precision, it is effective to use a relative speed vector of the vehicles. According to the collision avoidance assistance system of the present application, the relative speed vector of the first vehicle and the second vehicle is used as the speed information, and therefore the collision possibility of the first vehicle and the second vehicle can be determined with high precision.

[0033] Further, in the collision avoidance assistance system of the present application, the periphery information sensor device is mounted on the second vehicle, for example, to detect the position and speed of the first vehicle existing in a prescribed angular range in front of the second vehicle.

[0034] For two vehicles that are traveling on respective roads toward an intersection at which the two roads intersect, even in a case where the detection angular range of the periphery information sensor device of each vehicle is limited to a fixed angular range in front of the vehicle, if the vehicle speeds of the vehicles are of the same order, when the periphery information sensor device of one vehicle can detect the other vehicle, the periphery information sensor device of the other vehicle can also detect the one vehicle. Therefore, if the vehicles can collide with each other, collision avoidance processing is started for the vehicles at approximately the same time, thereby avoiding collision of the vehicles with each other.

[0035] However, in a scenario such as where two vehicles are traveling on respective roads toward an intersection at which a priority road and a non-priority road intersect, in most cases, the vehicle speed of a vehicle traveling on the non-priority road is lower than the vehicle speed of a vehicle traveling on the priority road. Thus, there are scenarios in which the vehicle speed of one vehicle is lower than the vehicle speed of the other vehicle. In such a scenario, the periphery information sensor device of the vehicle with the higher vehicle speed (high-speed vehicle) starts detecting the object vehicle (i.e., the low-speed vehicle) earlier than the periphery information sensor device of the vehicle with the lower vehicle speed (low-speed vehicle), and if the high-speed vehicle and the low-speed vehicle can collide, collision avoidance processing is started, but the periphery information sensor device of the low-speed vehicle cannot determine the possibility of collision because it has not detected the object vehicle (i.e., the high-speed vehicle), and thus even if there is a possibility of collision, collision avoidance processing is not started. Therefore, when the location at which the periphery information sensor device of the high-speed vehicle starts detecting the low-speed vehicle is near the collision location of the vehicles, collision with the low-speed vehicle cannot be avoided by implementation of collision avoidance processing for the high-speed vehicle alone.

[0036] However, according to the collision avoidance assistance system of the present application, in a case where the first vehicle is a low-speed vehicle and the second vehicle is a high-speed vehicle, when the collision avoidance assistance device of the second vehicle starts collision avoidance processing in order to avoid collision with the first vehicle, the collision avoidance assistance device of the first vehicle is sent information (collision information) related to collision with the second vehicle, and the collision avoidance assistance device of the first vehicle starts collision avoidance processing for the first vehicle based on the collision information. Therefore, even in a case where the vehicle speed of the first vehicle is lower than the vehicle speed of the second vehicle, collision of the first vehicle with the second vehicle can be more reliably avoided.

[0037] The constituent elements of the present application are not limited to the embodiments of the present application described below with reference to the drawings. Other objects, other features, and other advantages of the present application will be readily understood from the description of the embodiments of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 is a diagram showing a collision avoidance assistance system of an embodiment of the present application.

[0039] Figure 2 is a diagram showing a scenario in which a collision avoidance assistance system of an embodiment of the present application functions.

[0040] Figure 3 is a diagram showing a collision avoidance assistance device of a collision avoidance assistance system of an embodiment of the present application.

[0041] Figure 4 is a flowchart showing a routine executed by each collision avoidance assistance device of a collision avoidance assistance system of an embodiment of the present application.

[0042] Figure 5 is a flowchart showing a routine executed by each collision avoidance assistance device of a collision avoidance assistance system of an embodiment of the present application.

[0043] Figure 6 is a flowchart showing a routine executed by each collision avoidance assistance device of a collision avoidance assistance system of an embodiment of the present application.

[0044] Figure 7 is a diagram showing a specific scenario in which a collision avoidance assistance system of an embodiment of the present application functions, Figure 7 (A) of FIG. 10 is a diagram showing a scenario in which one vehicle is traveling on a priority road toward an intersection of the priority road and a non-priority road, and another vehicle is traveling on a non-priority road toward the intersection of the priority road and the non-priority road, Figure 7 (B) of FIG. 10 is a diagram showing a scenario in which the two vehicles further approach the intersection.

[0045] EXPLANATION OF REFERENCE NUMERALS

[0046] 10: collision avoidance assistance device, 66: GPS device, 67: transceiver device, 70: peripheral information sensor device, 71: camera, 72: radar sensor, 90: ECU, 100: collision avoidance assistance system, 200: host vehicle, 230: object vehicle. DETAILED DESCRIPTION

[0047] Hereinafter, a collision avoidance assistance system of an embodiment of the present application will be described with reference to the drawings. As shown in FIG. 1, a collision avoidance assistance system 100 of the present embodiment is mounted on a host vehicle 200. The collision avoidance assistance system 100 includes a collision avoidance assistance device 10, a GPS device 66, a transceiver device 67, a peripheral information sensor device 70, a camera 71, and a radar sensor 72. Figure 1As shown, the collision avoidance assist system 100 of this invention includes a plurality of collision avoidance assist devices 10 mounted on each vehicle 200, and is a system that uses wireless communication (vehicle-to-vehicle communication) between these collision avoidance assist devices 10 to avoid collisions between the vehicles 200. Figure 2 As shown, the collision avoidance assist system 100 functions in scenarios where two or more vehicles 200 are traveling within the area where the collision avoidance assist device 10 can communicate with each other.

[0048] <ECU>

[0049] like Figure 3 As shown, the collision avoidance assist device 10 includes an ECU 90. ECU is short for Electronic Control Unit. The ECU 90 has a microcomputer as its main component. The microcomputer includes a CPU, ROM, RAM, non-volatile memory, and interfaces, etc. The CPU performs various functions by executing instructions, programs, or routines stored in the ROM.

[0050] <Driver, etc.>

[0051] The vehicle 200 is equipped with a drive unit 21, a braking unit 22 and a steering unit 23.

[0052] <Driver>

[0053] The drive unit 21 is a device that outputs driving force to the vehicle 200 to make the vehicle 200 move; for example, it is an internal combustion engine or a motor. The drive unit 21 is electrically connected to the ECU 90. The ECU 90 can control the driving force output from the drive unit 21 by controlling the operation of the drive unit 21.

[0054] <Brake Device>

[0055] Braking device 22 is a device that outputs braking force to vehicle 200 for braking vehicle 200; for example, it is a brake device. Braking device 22 is electrically connected to ECU 90. ECU 90 can control the braking force output from braking device 22 by controlling the operation of braking device 22.

[0056] <Steering mechanism>

[0057] Steering device 23 is a device that outputs steering force to vehicle 200 for steering purposes; for example, it is a power steering system. Steering device 23 is electrically connected to ECU 90. ECU 90 can control the steering force output from steering device 23 by controlling the operation of steering device 23.

[0058] <Sensors, etc.>

[0059] Moreover, the vehicle 200 is equipped with an accelerator pedal operation amount sensor 61, a brake pedal operation amount sensor 62, a steering angle sensor 63, a steering torque sensor 64, a vehicle speed sensor device 65, a GPS device 66, a transceiver device 67, and a peripheral information sensor device 70.

[0060] <Accelerator pedal operation amount sensor>

[0061] The accelerator pedal operation amount sensor 61 is electrically connected to the ECU 90. The accelerator pedal operation amount sensor 61 detects the operation amount of the accelerator pedal 31 and transmits information of the detected operation amount to the ECU 90. The ECU 90 acquires the operation amount of the accelerator pedal 31 as an accelerator pedal operation amount AP on the basis of the information. The ECU 90 acquires a requested driving force by calculation on the basis of the accelerator pedal operation amount AP and the running speed of the host vehicle 200. The requested driving force is a driving force requested to be output from the drive device 21. The ECU 90 controls the operation of the drive device 21 so as to output the requested driving force from the drive device 21 at the time of normal operation except when the collision avoidance process described later is implemented.

[0062] <Brake pedal operation amount sensor>

[0063] The brake pedal operation amount sensor 62 is electrically connected to the ECU 90. The brake pedal operation amount sensor 62 detects the operation amount of the brake pedal 32 and transmits information of the detected operation amount to the ECU 90. The ECU 90 acquires the operation amount of the brake pedal 32 as a brake pedal operation amount BP on the basis of the information. The ECU 90 acquires a requested braking force by calculation on the basis of the brake pedal operation amount BP. The requested braking force is a braking force requested to be output from the brake device 22. The ECU 90 controls the operation of the brake device 22 so as to output the requested braking force from the brake device 22 at the time of normal operation.

[0064] <Steering angle sensor>

[0065] The steering angle sensor 63 is electrically connected to the ECU 90. The steering angle sensor 63 detects the rotation angle of the steering wheel 33 of the host vehicle 200 with respect to a neutral position and transmits information of the detected rotation angle to the ECU 90. The ECU 90 acquires the rotation angle of the steering wheel 33 of the host vehicle 200 with respect to the neutral position as a steering angle SA on the basis of the information.

[0066] <Steering torque sensor>

[0067] The steering torque sensor 64 is electrically connected to the ECU 90. The steering torque sensor 64 detects a torque input by the driver to the steering shaft 34 via the steering wheel 33, and transmits information of the detected torque to the ECU 90. The ECU 90 acquires the torque input by the driver to the steering shaft 34 via the steering wheel 33 as the driver input torque TQ D on the basis of the information.

[0068] <Speed sensor device>

[0069] The speed sensor device 65 is a device that detects a traveling speed (vehicle speed) of the host vehicle 200, and is, for example, a wheel speed sensor provided to a wheel of the host vehicle 200. The speed sensor device 65 is electrically connected to the ECU 90. The speed sensor device 65 detects the vehicle speed of the host vehicle 200, and transmits a signal of information indicating the detected vehicle speed to the ECU 90. The ECU 90 acquires the traveling speed (vehicle speed SPD) of the host vehicle 200 on the basis of the information indicated by the signal (autonomous sensor information IF S).

[0070] The ECU 90 acquires a torque applied to the steering shaft 34 from the steering device 23 (assist steering torque TQ A) by computation on the basis of the acquired steering angle SA, driver input torque TQ D, and vehicle speed SPD. The assist steering torque TQ A is a torque applied to the steering shaft 34 in order to assist the steering operation of the driver on the steering wheel 33. The ECU 90 controls the operation of the steering device 23 in such a manner that the assist steering torque TQ A is output from the steering device 23.

[0071] <Speed sensor device>

[0072] The GPS device 66 is a device that receives a GPS signal SG G. The GPS device 66 is electrically connected to the ECU 90. The GPS device 66 receives the GPS signal SG G, and transmits the received GPS signal SG G to the ECU 90. The ECU 90 can acquire GPS information IF G indicated by the GPS signal SG G, and can acquire a position (coordinate position PO V) and a speed vector VC S of the host vehicle 200 on the basis of the GPS information IF G. The speed vector VC S of the host vehicle 200 is a parameter indicating the vehicle speed SPD and the traveling direction DR of the host vehicle 200. Note that the coordinate position PO V and the speed vector VC S of the host vehicle 200 acquired on the basis of the GPS information IF G are a position and a speed vector that are based on one coordinate system common to all vehicles 200.

[0073] <Transmitting / receiving device>

[0074] The transceiving device 67 is electrically connected to the ECU 90. The ECU 90 can transmit various wireless signals to the outside of the host vehicle 200 via the transceiving device 67. In addition, the ECU 90 can receive various wireless signals via the transceiving device 67.

[0075] <Peripheral Information Sensor Device>

[0076] The peripheral information sensor device 70 is a device that detects information of the periphery of the host vehicle 200, and in the present example, includes the video camera 71 and the radar sensor 72, but in addition thereto, can include an ultrasonic sensor (clearance sonar), and can include a laser radar (LiDAR) in place of the radar sensor 72. Note that the radar sensor 72 is, for example, a millimeter wave radar.

[0077] Although a plurality of video cameras 71 can be provided in the host vehicle 200 in a manner that enables photographing of all directions from the host vehicle 200, in the present example, one video camera 71 is provided in the host vehicle 200 in a manner that enables photographing of the front of the host vehicle 200. The video camera 71 can photograph a prescribed angular range in the up-down-left-right directions with the center of the host vehicle 200 in the width direction as the center, with the centerline extending in the front-rear direction of the host vehicle 200 as the center.

[0078] In addition, a plurality of radar sensors 72 can be provided in the host vehicle 200 in a manner that enables detection of objects in all directions from the host vehicle 200, but in the present example, one radar sensor 72 is provided in the host vehicle 200 in a manner that enables detection of objects in the front of the host vehicle 200. The radar sensor 72 can emit electromagnetic waves to a prescribed angular range in the up-down-left-right directions with the centerline of the host vehicle 200 as the center, and can receive electromagnetic waves (reflected waves) reflected by objects present in the range.

[0079] The peripheral information sensor device 70 is electrically connected to the ECU 90. The peripheral information sensor device 70 transmits a signal of information (autonomous sensor information IF_S) indicating an image photographed by the video camera 71 to the ECU 90, and transmits a signal of information (autonomous sensor information IF_S) indicating electromagnetic waves emitted by the radar sensor 72 and electromagnetic waves (reflected waves) received by the radar sensor 72 to the ECU 90. The ECU 90 acquires information of an image photographed by the video camera 71 as autonomous sensor information IF_S based on these signals, and acquires information (autonomous sensor information IF_S) of electromagnetic waves emitted by the radar sensor 72 and electromagnetic waves (reflected waves) received by the radar sensor 72.

[0080] The ECU 90 can sense objects (e.g., other vehicles) in front of the vehicle 200 based on the acquired autonomous sensor information IF_S. Furthermore, when the ECU 90 senses another vehicle as an object, it can obtain information such as "the distance between the other vehicle and the vehicle 200 (inter-vehicle distance DS_V)" and "the velocity vector VC_S (relative velocity vector VC_R) of the vehicle 200 relative to the other vehicle" based on the autonomous sensor information IF_S.

[0081] <The operation of the collision avoidance assist system>

[0082] Next, a summary of the operation of the collision avoidance assist system 100 will be explained. First, refer to... Figure 4 to Figure 6 The operation of each collision avoidance assist device 10 will be explained, and then, refer to Figure 7 A summary of the operation of each collision avoidance assist device 10 in a specific scenario is provided.

[0083] The collision avoidance assist device 10 has the functions of sending a vehicle driving information signal SG_V to the outside, sending a collision information signal SG_C to the outside, and implementing collision avoidance processing.

[0084] The vehicle driving information signal SG_V is a signal that indicates information related to the driving status of the vehicle 200 equipped with each collision avoidance assist device 10, and the collision information signal SG_C is a signal that indicates information related to a collision between two vehicles.

[0085] Furthermore, collision avoidance processing is a process used to avoid collisions between two vehicles, and in this example, it is either drive force suppression processing or forced braking processing. Drive force suppression processing is a process that limits the drive force applied to vehicle 200 to below a specified drive force or reduces the drive force applied to vehicle 200. Forced braking processing is a process that sets the drive force applied to vehicle 200 to zero and applies braking force to vehicle 200.

[0086] <Transmission of vehicle driving information signals>

[0087] Collision avoidance assist device 10 executes within a specified calculation cycle. Figure 4 The example shown. When starting Figure 4 In the example shown, the collision avoidance assist device 10 first obtains the coordinate position PO_V and velocity vector VC_S of the vehicle 200 based on the GPS information IF_G (step 405).

[0088] Then, the collision avoidance assist device 10 transmits a wireless signal (vehicle driving information signal SG_V) indicating the acquired coordinate position PO_V and velocity vector VC_S of the vehicle 200 to the outside via the transceiver 67 of the vehicle 200 (step 410). In this example, the vehicle driving information signal SG_V includes identification information indicating the source of the vehicle driving information signal SG_V (i.e., the collision avoidance assist device 10 that transmits the vehicle driving information signal SG_V).

[0089] <Issuance of collision information signals and implementation of collision avoidance procedures>

[0090] In addition, the collision avoidance assist device 10 executes within a specified calculation cycle. Figure 5 The example shown. When starting Figure 5 In the example shown, the collision avoidance assist device 10 first determines whether it has received a vehicle driving information signal SG_V from the collision avoidance assist device 10 of another vehicle 220 (step 505).

[0091] If no vehicle driving information signal SG_V is received from the collision avoidance assist device 10 of other vehicles 220 (the determination is "No" in step 505), the collision avoidance assist device 10 terminates the routine.

[0092] On the other hand, when a vehicle driving information signal SG_V is received from the collision avoidance assist device 10 of another vehicle 220 (a "yes" determination is made in step 505), the collision avoidance assist device 10 identifies the other vehicle 220 as the target vehicle 230, and obtains the coordinate position PO_V and velocity vector VC_S of the target vehicle 230 based on the vehicle driving information IF_V represented by the received vehicle driving information signal SG_V (step 510).

[0093] Next, the collision avoidance assist device 10 obtains the coordinate position PO_V and velocity vector VC_S of the vehicle 200 at that time point based on the GPS information IF_G provided from the GPS device 66 of the vehicle 200 (step 515).

[0094] The collision avoidance assist device 10 obtains the distance (inter-vehicle distance DS_V) between the vehicle 200 and the target vehicle 230 based on the coordinate position PO_V of the target vehicle 230 and the coordinate position PO_V of the vehicle 200 (step 520). Furthermore, the collision avoidance assist device 10 obtains the velocity vector VC_S of the target vehicle 230 relative to the vehicle 200 (relative velocity vector VC_R) based on the velocity vector VC_S of the target vehicle 230 and the velocity vector VC_S of the vehicle 200 (step 520).

[0095] Further, the collision avoidance assistance device 10 acquires "a distance between the host vehicle 200 and the subject vehicle 230 (inter-vehicle distance DS_V)" and "a speed vector VC_S of the subject vehicle 230 with respect to the host vehicle 200 (relative speed vector VC_R)" based on autonomous sensor information IF_S provided from the periphery information sensor device 70 of the host vehicle 200 (step 525).

[0096] The collision avoidance assistance device 10 performs a fusion process on "the inter-vehicle distance DS_V acquired based on the GPS information IF_G (inter-vehicle communication information)" and "the inter-vehicle distance DS_V acquired based on the autonomous sensor information IF_S", thereby acquiring an inter-vehicle distance DS_V with higher precision (step 530). Further, the collision avoidance assistance device 10 performs a fusion process on "the relative speed vector VC_R acquired based on the GPS information IF_G (inter-vehicle communication information)" and "the relative speed vector VC_R acquired based on the autonomous sensor information IF_S", thereby acquiring a relative speed vector VC_R with higher precision (step 530).

[0097] Then, the collision avoidance assistance device 10 acquires a predicted time to collision TTC based on the acquired inter-vehicle distance DS_V and the relative speed vector VC_R (step 535). The predicted time to collision TTC is a time predicted to be required until the host vehicle 200 collides with the subject vehicle 230 in a case where the host vehicle 200 and the subject vehicle 230 travel while maintaining the vehicle speeds at the point in time.

[0098] The collision avoidance assistance device 10 determines whether or not a process for avoiding a collision between the host vehicle 200 and the subject vehicle 230 (collision avoidance process) needs to be implemented based on the acquired predicted time to collision TTC (step 540). In the present example, the collision avoidance assistance device 10 determines whether or not the predicted time to collision TTC becomes equal to or less than a prescribed predicted time to collision TTCth, and determines that the collision avoidance process needs to be implemented in a case where the predicted time to collision TTC becomes equal to or less than the prescribed predicted time to collision TTCth, and determines that the collision avoidance process does not need to be implemented in a case where the predicted time to collision TTC is longer than the prescribed predicted time to collision TTCth.

[0099] In a case where it is determined that the collision avoidance process does not need to be implemented (YES determination in step 540), the collision avoidance assistance device 10 ends the routine.

[0100] On the other hand, if it is determined that collision avoidance processing is required (a "yes" determination in step 540), the collision avoidance assist device 10 obtains the requested speed limit value SPD_M (step 545). The requested speed limit value SPD_M is the upper limit value of the speed SPD of the target vehicle 230 that should be requested from the collision avoidance assist device 10 of the target vehicle 230 to avoid a collision between the vehicle 200 and the target vehicle 230.

[0101] Then, the collision avoidance assist device 10 transmits a wireless signal (collision information signal SG_C) to the outside world, indicating the acquired requested maximum speed limit value SPD_M and predicted arrival time TTC, as well as collision information IF_C (step 550). At this time, the collision information signal SG_C includes identification information indicating that the collision information signal SG_C is a signal heading towards the target vehicle 230.

[0102] Furthermore, the collision avoidance assist device 10 implements appropriate collision avoidance measures to avoid a collision between the vehicle 200 and the object vehicle 230 (step 555).

[0103] <Implementation of Collision Avoidance Handling>

[0104] In addition, the collision avoidance assist device 10 executes within a specified calculation cycle. Figure 6 The example shown. When starting Figure 6 In the routine shown, the collision avoidance assist device 10 first determines whether it has received a collision information signal SG_C, which includes identification information indicating that it is heading toward the vehicle 200 (step 605).

[0105] If a collision information signal SG_C, which includes identification information indicating that the vehicle is heading towards the vehicle 200, is not received (the determination is "No" in step 605), the collision avoidance assist device 10 terminates the routine.

[0106] On the other hand, when a collision information signal SG_C is received, which includes identification information indicating that the signal is heading towards the vehicle 200 (determined as "yes" in step 605), the collision avoidance assist device 10 obtains the requested speed limit value SPD_M and the predicted arrival time TTC based on the collision information IF_C represented by the collision information signal SG_C (step 610).

[0107] The collision avoidance assist device 10 performs appropriate collision avoidance processing (step 615) to avoid a collision between the vehicle 200 and other vehicles 220 that have issued a collision information signal SG_C, based on the obtained requested speed limit value SPD_M and predicted arrival time TTC.

[0108] <Specific Examples>

[0109] Next, with Figure 7 The operation of each collision avoidance assist device 10 will be explained using the scenario shown as an example. Figure 7 The scenario shown is that one vehicle (first vehicle 201) is traveling on non-priority road 301 toward the intersection of non-priority road 301 and priority road 302 (intersection 303), while the other vehicle (second vehicle 202) is traveling on priority road 302 toward the intersection of non-priority road 301 and priority road 302 (intersection 303).

[0110] The collision avoidance assist device 10 of the first vehicle 201 and the collision avoidance assist device 10 of the second vehicle 202 respectively send out vehicle driving information signals SG_V to the outside.

[0111] like Figure 7 As shown in (A), when the first vehicle 201 and the second vehicle 202 approach the intersection 303 and enter the area where the first vehicle 201 can communicate with the second vehicle 202, the collision avoidance assist device 10 of the second vehicle 202 receives the vehicle driving information signal SG_V issued by the collision avoidance assist device 10 of the first vehicle 201.

[0112] When the vehicle driving information signal SG_V is received, the collision avoidance assist device 10 of the second vehicle 202 obtains the "distance between the first vehicle 201 and the second vehicle 202 (inter-vehicle distance DS_V)" and the "velocity vector VC_S of the first vehicle 201 relative to the second vehicle 202 (relative velocity vector VC_R)" based on the vehicle driving information signal SG_V.

[0113] like Figure 7 As shown in (B), when the first vehicle 201 approaches the intersection 303 further, the surrounding information sensor device 70 of the second vehicle 202 detects information related to the first vehicle 201 as autonomous sensor information IF_S.

[0114] When the peripheral information sensor device 70 of the second vehicle 202 detects information related to the first vehicle 201 (autonomous sensor information IF_S), the collision avoidance assist device 10 of the second vehicle 202 obtains the "distance between the first vehicle 201 and the second vehicle 202 (inter-vehicle distance DS_V)" and the "velocity vector VC_S of the first vehicle 201 relative to the second vehicle 202 (relative velocity vector VC_R)" based on the autonomous sensor information IF_S.

[0115] The collision avoidance assist device 10 of the second vehicle 202 performs fusion processing on the inter-vehicle distance DS_V acquired on the basis of the GPS information IF_G (inter-vehicle communication information) and the inter-vehicle distance DS_V acquired on the basis of the autonomous sensor information IF_S, thereby acquiring an inter-vehicle distance DS_V with higher accuracy. Also, the collision avoidance assist device 10 of the second vehicle 202 performs fusion processing on the relative velocity vector VC_R acquired on the basis of the GPS information IF_G (inter-vehicle communication information) and the relative velocity vector VC_R acquired on the basis of the autonomous sensor information IF_S, thereby acquiring a relative velocity vector VC_R with higher accuracy.

[0116] The collision avoidance assist device 10 of the second vehicle 202 acquires a predicted time to collision TTC with respect to the first vehicle 201 on the basis of the acquired inter-vehicle distance DS_V and relative velocity vector VC_R, and determines whether or not collision avoidance processing needs to be implemented on the basis of the predicted time to collision TTC.

[0117] When it is determined that collision avoidance processing needs to be implemented, the collision avoidance assist device 10 of the second vehicle 202 acquires a requested maximum speed value SPD_M with respect to the first vehicle 201, and transmits a collision information signal SG_C indicating the requested maximum speed value SPD_M and the predicted time to collision TTC with respect to the first vehicle 201 acquired previously as collision information IF_C to the outside. The collision information signal SG_C includes identification information indicating that the collision information signal SG_C is a signal to the first vehicle 201. Also, at this time, the collision avoidance assist device 10 of the second vehicle 202 implements appropriate collision avoidance processing.

[0118] On the other hand, when the collision avoidance assist device 10 of the second vehicle 202 transmits the collision information signal SG_C, the collision avoidance assist device 10 of the first vehicle 201 receives the collision information signal SG_C. As described above, the collision information signal SG_C includes identification information indicating that the collision information signal SG_C is a signal to the first vehicle 201, so when the collision information signal SG_C is received, the collision avoidance assist device 10 of the first vehicle 201 acquires the requested maximum speed value SPD_M and the predicted time to collision TTC on the basis of the collision information signal SG_C. Then, the collision avoidance assist device 10 of the first vehicle 201 implements appropriate collision avoidance processing for avoiding collision of the first vehicle 201 with the second vehicle 202 on the basis of the requested maximum speed value SPD_M and the predicted time to collision TTC.

[0119] <Effects>

[0120] According to the collision avoidance assistance system 100, the collision avoidance assistance device 10 of one of the vehicles (the host vehicle 200, the second vehicle 202) acquires the position information and the speed information of the vehicle of the other party (the object vehicle 230, the first vehicle 201) based on the wireless signal emitted from the collision avoidance assistance device 10 of the vehicle of the other party. In other words, the collision avoidance assistance device 10 of the host vehicle 200 acquires the position information and the speed information of the object vehicle 230 based on the information (inter-vehicle communication information) provided by the collision avoidance assistance device 10 of the object vehicle 230 in a wireless signal.

[0121] Also, the collision avoidance assistance device 10 of the host vehicle 200 acquires the position information and the speed information of the object vehicle 230 by the periphery information sensor device 70 of the host vehicle 200. In other words, the collision avoidance assistance device 10 of the host vehicle 200 acquires the position information and the speed information of the object vehicle 230 based on the information (autonomous sensor information IF S) provided from the periphery information sensor device 70 of the host vehicle 200.

[0122] Then, the collision avoidance assistance device 10 of the host vehicle 200 combines the inter-vehicle communication information and the autonomous sensor information to judge the possibility of collision (collision possibility) of the host vehicle 200 with the object vehicle 230.

[0123] For example, if the possibility of collision (collision possibility) of the vehicle that is traveling on one of the roads toward the intersection at which the two roads intersect with the vehicle that is traveling on the other road toward the intersection at which the two roads intersect cannot be judged with high precision, the start of the collision avoidance process for avoiding the collision of the vehicles with each other in each vehicle can be late, or, on the contrary, can be early. If the start of the collision avoidance process is late, the collision of the vehicles with each other cannot be avoided, and, furthermore, if the start of the collision avoidance process is early, unnecessary collision avoidance process can be implemented. Therefore, in order to avoid the implementation of unnecessary collision avoidance process, and in order to avoid the collision of the vehicles with each other, it is necessary to determine the collision possibility with high precision, and therefore, it is necessary to acquire the position information and the speed information of the host vehicle with high precision, and it is necessary to acquire the position information and the speed information of the object vehicle with high precision.

[0124] The simultaneity of the information of the autonomous sensor information (i.e., the consistency of the value indicated by the information at the time of acquisition of the information with the actual value at the point of time of acquisition of the information) is higher than the simultaneity of the information of the inter-vehicle communication information. Therefore, compared with acquiring the position information and the speed information of the object vehicle based on the inter-vehicle communication information, acquiring the position information and the speed information of the object vehicle based on the autonomous sensor information enables acquiring the position information and the speed information with higher simultaneity.

[0125] However, in a case where two vehicles are traveling while maintaining a front-rear relationship in a traveling direction, the collision avoidance assist device of the rear vehicle (the host vehicle) can acquire position information and speed information of the front vehicle (the object vehicle) with high precision based on autonomous sensor information, but in a scenario where two vehicles are traveling on respective roads toward an intersection at which the two roads intersect, it is difficult to acquire the position information and the speed information of the object vehicle with high precision based on autonomous sensor information. That is, while there is an advantage that the position information and the speed information of the object vehicle are acquired with high simultaneity of information based on autonomous sensor information, there is a disadvantage that it is difficult to acquire the position information and the speed information with high precision.

[0126] On the other hand, since the inter-vehicle communication information is information emitted by the collision avoidance assist device of the object vehicle, the position information and the speed information of the object vehicle acquired based on the inter-vehicle communication information are inherently high in precision, but as described above, the inter-vehicle communication information is low in simultaneity. That is, while there is an advantage that the position information and the speed information of the object vehicle are acquired with high precision based on the inter-vehicle communication information, there is a disadvantage that the information is low in simultaneity.

[0127] Further, in a case where two vehicles are traveling while maintaining a front-rear relationship in a traveling direction, the collision avoidance assist device of the rear vehicle (the host vehicle) can always acquire autonomous sensor information related to the front vehicle (the object vehicle), but in a scenario where two vehicles are traveling on respective roads toward an intersection at which the two roads intersect, it is sometimes impossible to acquire autonomous sensor information related to the object vehicle due to a reason that the other vehicle (the object vehicle) is hidden behind an object or the like with respect to the one vehicle (the host vehicle). Such a disadvantage also exists in acquisition of the position information and the speed information of the object vehicle based on autonomous sensor information.

[0128] In this regard, even in a scenario where the collision avoidance assist device of the host vehicle cannot acquire autonomous sensor information related to the object vehicle due to a reason that the other vehicle (the object vehicle) is hidden with respect to the one vehicle (the host vehicle), the collision avoidance assist device of the host vehicle can acquire the position information and the speed information of the object vehicle based on the inter-vehicle communication information.

[0129] According to the collision avoidance assistance system 100, the collision avoidance assistance device 10 of the own vehicle 200 combines the inter-vehicle communication information and the autonomous sensor information to determine the possibility of collision (collision possibility) of the own vehicle 200 with the subject vehicle 230. Therefore, the disadvantages of acquisition of the position information and the speed information of the subject vehicle 230 based on the inter-vehicle communication information and the disadvantages of acquisition of the position information and the speed information of the subject vehicle 230 based on the autonomous sensor information are complementary, and as a result, the collision possibility can be determined with high precision. Therefore, in a scenario in which the vehicles are traveling on respective roads toward an intersection, unnecessary implementation of collision avoidance processing can be avoided, and collision of the vehicles with each other can be more reliably avoided.

[0130] Further, with respect to two vehicles that are traveling on respective roads toward an intersection at which the two roads intersect, even in a case in which the detection angle range of the peripheral information sensor device of each vehicle is limited to a fixed angle range in front of the vehicle, in a case in which the vehicles cannot see each other due to a building or the like in the vicinity of the intersection, if the vehicle speeds of the vehicles are of the same order, when the peripheral information sensor device of one vehicle can detect the other vehicle, the peripheral information sensor device of the other vehicle can also detect the one vehicle. Therefore, if the vehicles can collide with each other, collision avoidance processing is started for the vehicles at approximately the same time, and collision of the vehicles with each other is avoided.

[0131] However, for example, in a scenario in which two vehicles are traveling on respective roads toward an intersection at which a priority road and a non-priority road intersect, in most cases, the vehicle speed of the vehicle that is traveling on the non-priority road is lower than the vehicle speed of the vehicle that is traveling on the priority road. Thus, there are scenarios in which the vehicle speed of one vehicle is lower than the vehicle speed of the other vehicle. In such a scenario, the peripheral information sensor device of the vehicle with the higher vehicle speed (high-speed vehicle) starts to detect the subject vehicle (i.e., the low-speed vehicle) before the peripheral information sensor device of the vehicle with the lower vehicle speed (low-speed vehicle), and if the high-speed vehicle and the low-speed vehicle can collide, collision avoidance processing is started, but the peripheral information sensor device of the low-speed vehicle cannot determine the collision possibility because the subject vehicle (i.e., the high-speed vehicle) is not detected, and therefore, even if there is a collision possibility, collision avoidance processing is not started. Therefore, when the location at which the peripheral information sensor device of the high-speed vehicle starts to detect the low-speed vehicle is in the vicinity of the collision location of the vehicles, collision with the low-speed vehicle cannot be avoided by implementation of collision avoidance processing for the high-speed vehicle alone.

[0132] However, according to the collision avoidance assistance system 100, the collision avoidance assistance device 10 of the high-speed vehicle (the second vehicle 202) issues, to the collision avoidance assistance device 10 of the low-speed vehicle, information (collision information IF C) related to a collision with the high-speed vehicle when starting the collision avoidance process for avoiding a collision with the low-speed vehicle (the first vehicle 201), and the collision avoidance assistance device 10 of the low-speed vehicle starts appropriate collision avoidance processing based on the collision information IF C. Thus, a collision between the high-speed vehicle and the low-speed vehicle can be more reliably avoided.

[0133] Note that the present application is not limited to the above-described embodiments, and various modifications can be made within the scope of the present application.

Claims

1. A collision avoidance assist system, comprising: As a collision avoidance assist device for the first vehicle, a collision avoidance assist device capable of emitting wireless signals to the outside of the first vehicle. The system includes a collision avoidance assist device for the second vehicle, capable of receiving wireless signals emitted from the first vehicle and emitting wireless signals to the outside of the second vehicle, thereby preventing a collision between the first and second vehicles. The collision avoidance assist system is configured as follows: The collision avoidance assist device of the first vehicle emits a first wireless signal to the outside of the first vehicle, wherein the first wireless signal represents the position information and speed information of the first vehicle and represents identification information, and the identification information represented by the first wireless signal indicates that the first wireless signal is a signal emitted from the first vehicle. Upon receiving the first wireless signal, the collision avoidance assist device of the second vehicle acquires the position and speed information of the first vehicle based on the first wireless signal. If, based on the acquired position and speed information of the first vehicle and the position and speed information of the first vehicle obtained by a peripheral information sensor device mounted on the second vehicle, it determines that a collision between the first and second vehicles is possible, it emits a second wireless signal to the outside of the second vehicle and performs collision avoidance processing on the second vehicle to avoid a collision between the first and second vehicles. The second wireless signal represents collision information and identification information; the collision information indicates that a collision between the first and second vehicles is possible, and the identification information represents that the second wireless signal is directed towards the first vehicle. The second wireless signal includes a requested upper speed limit and a predicted time of arrival. The requested upper speed limit is the upper speed limit of the first vehicle that should be requested from the collision avoidance assist device of the first vehicle to avoid a collision between the second vehicle and the first vehicle. The predicted time of arrival is obtained based on the location information and the speed information and is predicted to be the time required until the second vehicle and the first vehicle collide, provided that the second vehicle and the first vehicle maintain the speeds at the time when the location information and the speed information were obtained, respectively. Upon receiving the second wireless signal, the collision avoidance assist device of the first vehicle performs collision avoidance processing on the first vehicle to avoid a collision between the first vehicle and the second vehicle based on the requested upper speed limit and the predicted time of arrival.

2. The collision avoidance assist system according to claim 1, wherein, The location information is obtained based on GPS signals.

3. The collision avoidance assist system according to claim 1, wherein, The speed information is obtained based on GPS signals.

4. The collision avoidance assist system according to any one of claims 1 to 3, wherein, The speed information is the relative speed vector between the first vehicle and the second vehicle.

5. The collision avoidance assist system according to any one of claims 1 to 3, wherein, The surrounding information sensor device is mounted on the second vehicle to detect the position and speed of the first vehicle within a specified angular range in front of the second vehicle.

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