Vehicle driving control device

Abstract

To reduce the risk of traffic flow disturbance at an intersection or contact / collision with other traffic participants during operation of a risk mitigation function.SOLUTION: In a running control device of a vehicle 1 having an automatic operation device with remote monitoring / operation, which has a risk mitigation function (RMF) for stopping the vehicle 1 at a target stop position when it is difficult to continue the remote monitoring / operation, and an override function for transferring to a manual operation mode by stopping automatic running by an occupant's operational intervention. On the basis of location information and map information on the vehicle 1, a plurality of target stop position candidates are searched, and when a target stop position candidate located on a route different from an automatic running target route PA is selected as a target stop position from among the plurality of target stop position candidates near an intersection, an override threshold which is a determination criterion of the occupant's or a passenger's operational intervention is changed to a value larger than the override threshold during non-operation of the RMF.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a vehicle driving control device, and more particularly to a risk reduction function for a vehicle during automatic driving through remote monitoring and operation. [Background technology]

[0002] Development is underway to develop technologies that will enable unmanned vehicles to be driven under specific conditions using remotely monitored and operated automated driving devices. Remotely operated automated driving systems are configured to monitor the driving of a vehicle operated by an automated driving device equipped with, for example, an Accelerated Control System (ACCS) or a continuous automatic steering system from a remote control base station and operate the vehicle as necessary. In such remotely operated automated driving systems, if for some reason it becomes difficult to continue remote monitoring and operation while the vehicle is being driven by the automated driving device, it is necessary to respond using the risk mitigation function (RMF) of the automated driving device installed in the vehicle.

[0003] For example, Patent Document 1 discloses that when an abnormality occurs in an autonomously driven vehicle, an evacuation site is searched for, a taxiway to the evacuation site is calculated, and the vehicle is controlled to travel along the taxiway by automatic steering. As the evacuation site, a space where the vehicle can be parked, such as a vacant lot or a parking lot of a commercial facility, is set. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-152963 Summary of the Invention [Problem to be solved by the invention]

[0005] However, if the RMF is activated near an intersection, there is a risk that the vehicle may cross paths with other traffic participants at the intersection, causing traffic flow disruptions and contact or collision with other traffic participants while guiding the vehicle to an evacuation location.

[0006] The present invention has been made in consideration of the above-described circumstances, and its purpose is to reduce the risk of traffic flow disruption at intersections and contact or collision with other traffic participants when the risk mitigation function is activated. [Means for solving the problem]

[0007] According to one aspect of the present invention, there is provided a driving control device for a vehicle equipped with an automatic driving device for performing automatic driving by remote monitoring and operation, and the driving control device has a risk mitigation function (RMF) that performs risk mitigation control to stop the vehicle at a target stopping position when it becomes difficult to continue remote monitoring and operation, and an override function that stops automatic driving by the automatic driving device and switches to a manual driving mode by operational intervention of a vehicle occupant or passenger, and the automatic driving device is always , the operation of the RMF Preparation The system is configured to search for multiple target stop position candidates based on the vehicle's position information and map information, and when the RMF is activated near an intersection, if a target stop position candidate located on a route different from the target route of the automatic driving is selected as the target stop position from among the multiple target stop position candidates, the system changes the override threshold, which is the criterion for determining whether the occupant or passenger should intervene, to a value greater than the override threshold when the RMF is not activated. [Effects of the Invention]

[0008] The vehicle cruise control device according to the present invention can reduce the risk of disruption of traffic flow at an intersection and contact or collision with other traffic participants when the risk reduction function is activated near an intersection. [Brief explanation of the drawings]

[0009] [Figure 1]FIG. 1 is a schematic diagram showing a vehicle cruise control system according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a schematic plan view showing a group of external sensors of a vehicle. [Figure 3] FIG. 3 is a block diagram showing a vehicle driving control system. [Figure 4] 4(a) and 4(b) are diagrams illustrating the relationship between the stopping position of a vehicle and other traffic participants around an intersection. [Figure 5] FIG. 5 is a diagram for explaining the selection of a target stopping position at a crossroads. [Figure 6] FIG. 6 is a diagram conceptually illustrating a risk occurrence situation due to override when RMF is activated. [Figure 7] FIG. 7 is a diagram illustrating the effect of changing the override threshold when the RMF is activated. [Figure 8] 8(a) to 8(d) are diagrams illustrating the relationship between the override threshold and the course change when the RMF is activated. [Figure 9] FIG. 9 is a flowchart illustrating the flow of the RMF operation according to the first embodiment. [Figure 10] FIG. 10 is a schematic diagram showing a vehicle driving control system according to the second embodiment of the present invention. [Figure 11] FIG. 11 is a diagram for explaining the selection of a target stopping position at a crossroads. DETAILED DESCRIPTION OF THE INVENTION

[0010] -First embodiment- A first embodiment of the present invention will be described in detail below with reference to the drawings. A cruise control system for a vehicle 1 according to the first embodiment is configured to be capable of performing automated driving equivalent to SAE (Society of Automotive Engineers) Level 4, which performs all driving operations within an operational design domain (ODD). The cruise control system for the vehicle 1 is a remote-controlled automated driving system capable of automated driving through remote monitoring and operation, and the vehicle 1 is envisioned to be a service car such as a taxi or rental car that provides an unmanned automated driving transportation service.

[0011] 1 to 3, a vehicle 1 equipped with a cruise control system according to a first embodiment includes, in addition to typical automobile components such as an engine and a body, external sensors 21 for detecting the environment around the vehicle, internal sensors 22 for detecting vehicle information, a map information database 23, positioning means 24, a group of controllers / actuators for speed control and steering control, an ACC controller 15 for controlling the distance between vehicles, an automatic steering controller 16 for automatic steering control, and an automatic driving device 10 for integrating these to perform route tracking control, in order to perform the recognition, judgment, and operation that have traditionally been performed by a driver on the vehicle side. The vehicle 1 also includes a communication device 25 for communicating remote control commands and vehicle information, vehicle position information, etc. with a remote control base station 25R.

[0012] The controller / actuator group for speed control and steering control includes an EPS (electric power steering) controller 31 for steering control, an engine controller 32 for acceleration / deceleration control, and an ESP / ABS controller 33. ESP (registered trademark; Electronic Stability Program) includes ABS (anti-lock braking system) to form a stability control system (vehicle behavior stabilization control system).

[0013] The external environment sensor 21 consists of multiple detection means for inputting the presence and relative distance of road dividing lines that define the current lane and adjacent lanes, other vehicles, obstacles, people, etc. around the current vehicle as external environment data such as image data or point cloud data into the automatic driving device 10.

[0014] For example, as shown in Fig. 2, the vehicle 1 is equipped with a millimeter-wave radar (211) and a camera (212) as forward detection means 211, 212, a LIDAR (laser image detection / ranging) as front-side detection means 213 and rear-side detection means 214, and a camera (back camera) as rear detection means 215. The external sensor 21 covers 360 degrees around the vehicle and is capable of detecting the positions and distances of other vehicles and obstacles within a predetermined range in each of the front, rear, left, and right directions of the vehicle, as well as the positions of lane markings in the vehicle's lane and adjacent lanes. Note that millimeter-wave radar (or LIDAR) can also be added as rear detection means.

[0015] The internal sensor 22 is made up of a plurality of detection means for measuring physical quantities that represent the motion state of the vehicle, such as a vehicle speed sensor, a yaw rate sensor, an acceleration sensor, etc. As shown in Fig. 3, the measured values ​​of the internal sensor 22 are input to the automatic driving device 10, the ACC controller 15, the automatic steering controller 16, and the EPS controller 31, and are processed together with the input from the external sensor 21.

[0016] The automatic operation device 10 includes an environmental state estimation unit 11, a risk mitigation function (RMF) unit 12, a route generation unit 13, and a vehicle control unit 14, and is composed of a computer for performing the functions described below, namely, a ROM that stores programs and data, a CPU that performs arithmetic processing, a RAM that reads the programs and data and stores dynamic data and arithmetic processing results, and an input / output interface.

[0017] The environmental state estimation unit 11 acquires the absolute position of the vehicle by matching the vehicle position information obtained by positioning means 24, such as a Global Navigation Satellite System (GNSS), with the map information in a map information database 23, and estimates the positions of lane markings in the vehicle's lane and adjacent lanes, and the positions and speeds of other vehicles, based on external data such as image data and point cloud data acquired by an external sensor 21. The environmental state estimation unit 11 also acquires the vehicle's motion state from internal data measured by an internal sensor 22.

[0018] The RMF unit 12 determines whether to activate a risk mitigation function (RMF) that safely stops the vehicle 1 within a target stopping area when road conditions or environmental conditions are outside the operation design domain (ODD) or when the system does not operate normally, based on information input from the environmental state estimation unit 11. In this embodiment, the RMF is configured to activate when it becomes difficult to continue remote monitoring and operation of the cruise control system by the remote control base station 25R via the communication device 25.

[0019] Before and during the RMF activation, the notification unit 17 notifies the occupants and passengers of the vehicle 1 and road users outside the vehicle. Furthermore, as will be described later, if the traveling direction of the vehicle 1 changes due to the activation of the RMF, the notification unit 17 may be configured to notify that the traveling direction will change. The notification unit 17 may also be configured to notify people inside and outside the vehicle that the autonomous traveling by remote monitoring and operation has stopped. The notification unit 17 may use visual methods such as turning on a lamp or displaying a text, and / or auditory methods such as outputting a voice.

[0020] The route generation unit 13 is configured to generate a target route from the vehicle position estimated by the environmental state estimation unit 11 to a destination. The route generation unit 13 searches for a route from the departure point to the destination based on the vehicle position information and map information, and generates a rough target route, a so-called global route. Furthermore, the route generation unit 13 generates a detailed target route, a so-called local route, for autonomous driving such as lane keeping, lane changes, and course changes, based on the positions of adjacent lane markings, the positions and speeds of other vehicles, and the motion state of the vehicle estimated by the environmental state estimation unit 11. The route generation unit 13 is further configured to generate a target route for RMF operation to a target stopping position when the vehicle 1 is stopped by RMF operation.

[0021] The vehicle control unit 14 calculates a target vehicle speed and a target steering angle based on the target route generated by the route generation unit 13, and transmits a speed command for constant speed driving or vehicle-to-vehicle distance maintenance / following driving to the ACC controller 15, and transmits a steering angle command for route following to the EPS controller 31 via the automatic steering controller 16.

[0022] The vehicle speed is also input to the EPS controller 31 and the ACC controller 15. Because the steering reaction force changes depending on the vehicle speed, the EPS controller 31 refers to a steering angle-steering torque map for each vehicle speed and sends a torque command to the steering mechanism 41. The engine controller 32, the ESP / ABS controller 33, and the EPS controller 31 control the engine 42, the brakes 43, and the steering mechanism 41, thereby controlling the longitudinal and lateral movements of the vehicle 1.

[0023] [Outline of the remote-controlled automated driving system] Next, an overview of the remote-controlled automated driving system will be described. The automated driving system in this embodiment is a remotely monitored and operated automated driving system, in which the traveling of vehicle 1 driven by the automated driving system is monitored by remote control base station 25R and is operated from remote control base station 25R as needed.

[0024] The autonomous driving system is a combination of an adaptive cruise control system (ACCS) and a continuous automatic steering system that automatically maintains and changes lanes continuously. The autonomous driving system can be executed when the ACC controller 15, which constitutes the adaptive cruise control system (ACC) together with the automatic driving device 10, and the automatic steering controller 16, which constitutes the continuous automatic steering system, are both operating.

[0025] An operator at the remote-controlled base station 25R sets a departure point and a destination before the vehicle 1 departs. The set departure point and destination are input from the remote-controlled base station 25R to the automatic driving device 10 of the vehicle 1 via the communication device 25. The route generation unit 13 generates a global route from the departure point to the destination based on the vehicle's position information and map information obtained from the environmental state estimation unit 11. Based on the generated global route, the route generation unit 13 generates a local route and a target vehicle speed based on external information (lanes, vehicle position, positions and speeds of other vehicles traveling in the lane in which the vehicle is traveling and adjacent lanes) obtained by the external sensor 21 and internal information (vehicle speed, yaw rate, acceleration) obtained by the internal sensor 22.

[0026] When the operator of the remote control base station 25R determines that the environmental conditions, road conditions, etc. are maintained within the system's operation design domain (ODD), he / she sends a start command to the automatic operation device 10 to cause the vehicle 1 to travel according to the generated target route and target vehicle speed.

[0027] The vehicle control unit 14 calculates the yaw rate γ and lateral acceleration (d 2 y / dt 2 ) the vehicle speed, attitude, and lateral displacement after Δt seconds are estimated from the relationship. Vehicle control unit 14 provides a steering angle command to EPS controller 31 via automatic steering controller 16 so that the lateral displacement after Δt seconds will be yt, and provides a speed command to ACC controller 15 so that the speed will be Vt after Δt seconds.

[0028] The ACC controller 15, automatic steering controller 16, EPS controller 31, engine controller 32, and ESP / ABS controller 33 operate independently of automatic steering, but can also be operated by command input from the automatic driving controller 10 while the automatic driving system is operating.

[0029] The ESP / ABS controller 33, which receives a deceleration command from the ACC controller 15, issues a hydraulic command to an actuator and controls the braking force of a brake 43, thereby controlling the vehicle speed. Furthermore, the engine controller 32, which receives an acceleration / deceleration command from the ACC controller 15, controls the actuator output (throttle opening) to issue a torque command to the engine 42, thereby controlling the driving force and thereby controlling the vehicle speed.

[0030] The ACC function (ACCS) functions as a combination of hardware and software, such as a millimeter wave radar as forward detection means 211 constituting the external sensor 21, the ACC controller 15, the engine controller 32, and the ESP / ABS controller 33.

[0031] In other words, if there is no preceding vehicle, the vehicle will travel at a constant speed with the ACC set speed (set speed) as the target vehicle speed.If the vehicle catches up with the preceding vehicle (if the preceding vehicle speed is equal to or lower than the ACC set speed), the vehicle will follow the preceding vehicle while maintaining a distance (set distance) according to the set time gap (time between vehicles = distance between vehicles / vehicle speed) in accordance with the speed of the preceding vehicle.

[0032] The continuous automatic steering system detects lane markings, the vehicle's position, and the positions and speeds of other vehicles traveling in adjacent lanes using the environmental state estimation unit 11 of the automatic operation device 10, based on image data and point cloud data acquired by external sensors 21 and vehicle information acquired by internal sensors 22. Based on this information, the continuous automatic steering system performs steering control using the EPS controller 31 via the automatic steering controller 16 to perform lane keeping control to keep the vehicle in the center of the lane and lane change control to cross lane markings.

[0033] That is, upon receiving a steering angle command from the automatic steering controller 16, the EPS controller 31 refers to a map of vehicle speed-steering angle-steering torque, issues a torque command to the actuator (EPS motor), and gives the steering mechanism 41 the target front wheel steering angle.

[0034] As described above, the autonomous driving system is a system configured by combining longitudinal control (speed control, inter-vehicle distance control) by the ACC controller 15 and lateral control (lane keeping control, lane change control) by the automatic steering controller 16. The remote-controlled autonomous driving system monitors the traveling of the vehicle 1 by the remote control base station 25R, and controls the traveling of the vehicle 1 according to remote control commands from the remote control base station 25R.

[0035] [Risk Mitigation Function (RMF) for Automated Driving Systems] While the autonomous driving system is operating, the environmental state estimation unit 11 constantly monitors whether the vehicle's running state, surrounding environmental conditions, etc. are maintained within the operation design domain (ODD) of the system, based on external information acquired through the external sensor 21, vehicle information acquired by the internal sensor 22, the communication status with the remote control base station 25R, etc. If the vehicle is outside the ODD or if the system is not operating normally, it is required to activate the RMF, which safely stops the vehicle 1 within the target stopping area.

[0036] Based on a signal from the environmental state estimation unit 11, the RMF unit 12 determines to activate the RMF when it becomes difficult for the remote control base station 25R to remotely monitor and operate the vehicle 1 due to, for example, a disconnection of communication with the remote control base station 25R or a failure of the communication device 25, and activates the RMF to guide the vehicle 1 to a target stopping area and stop it. The target stopping area for the RMF is usually set as a space on the target route for automated driving where the vehicle 1 can be stopped. However, if the RMF is activated near an intersection, there is a possibility that the vehicle 1 may cross paths with other traffic participants at the intersection or disrupt traffic flow while decelerating and guiding the vehicle 1 to the target stopping area on the target route.

[0037] The relationship between the stopping position of vehicle 1 and other traffic participants around an intersection will be explained with reference to Figures 4(a) and (b). Figures 4(a) and (b) respectively show examples of RMF operation near a crossroads intersection and a T-junction intersection without traffic lights. Note that while traffic rules include keeping to the left and keeping to the right, the following explanation will use keeping to the left as an example.

[0038] 4(a), the target route for vehicle 1 is set to a route that turns right at intersection C1, as indicated by arrow PA. In this example, in addition to vehicle 1, there may be a vehicle 2 moving straight to the right entering intersection C1 from the right on path P2, a vehicle 3 moving straight to the left entering intersection C1 from the left on path P3, and an oncoming vehicle 4 moving straight from the oncoming lane entering intersection C1 on path P4 around intersection C1. If it becomes difficult to continue communication between vehicle 1 and remote-controlled base station 25R near intersection C1, RMF unit 12 determines that RMF activation is necessary.

[0039] When a target stop position S is set on the target route after turning right at intersection C1, vehicle 1 turns right along route PA due to RMF activation in automatic driving device 10, and is then guided to target stop position S along the RMF route indicated by arrow PB and stopped there. In this case, when vehicle 1 turns right at intersection C1, there is a risk of crossing with a vehicle 2 moving straight to the right, a vehicle 3 moving straight to the left, and an oncoming vehicle 4 moving straight. In other words, by setting target stop area S on the target route for automatic driving when RMF is activated, multiple crossing points are created where there is a possibility of crossing with other traffic participants. As a result, at intersection C1, there is a risk of contact or collision with other traffic participants in a risk area RA, as shown in FIG. 4(a).

[0040] In the example of a T-junction shown in Fig. 4(b), the target route for vehicle 1 is set to a route that turns right at intersection C2, as indicated by arrow PA. In addition to vehicle 1, there is a possibility that, around intersection C2, there is a vehicle 2 moving straight to the right that is entering intersection C2 from the right on path P2, and a vehicle 3 moving straight to the left that is entering intersection C2 from the left on path P3. Here, if it becomes difficult to continue communication between vehicle 1 and remote-controlled base station 25R near intersection C2, RMF unit 12 determines that RMF activation is necessary.

[0041] When a target stopping area S is set on the target route after turning right at intersection C2, vehicle 1 turns right along route PA due to RMF activation of automatic operation device 10, and is then guided to target stopping position S along the route for RMF indicated by arrow PB, where it stops. In this case, when vehicle 1 turns right at intersection C2, there is a risk that vehicle 1 will intersect with vehicle 2 moving straight to the right and vehicle 3 moving straight to the left. In other words, by setting target stopping position S on the target route when RMF is activated, multiple intersections at which vehicle 1 may intersect with other traffic participants are created, and as shown in Figure 4(b), at intersection C2, there is a risk of contact or collision with other traffic participants in a risk area RA.

[0042] In this way, when RMF is activated near an intersection, if vehicle 1 turns right at the intersection, an intersection will occur with vehicle 2 moving straight to the right, vehicle 3 moving straight to the left, and / or oncoming vehicle 4. At such an intersection, there is a risk of contact or collision between vehicle 1 and other traffic participants. Furthermore, if the stopping position of vehicle 1 due to RMF is set in an area just before or just after the intersection, there is a possibility that it will disrupt the traffic flow of other traffic participants.

[0043] Therefore, in the first embodiment, when RMF is activated near an intersection, a target stopping position for RMF is set in an area that can reduce the risk of contact or collision between vehicle 1 and other traffic participants and further suppress the impact on the traffic flow of other traffic participants.

[0044] Here, the case where RMF operates near an intersection means, for example, a situation where, if RMF is activated to decelerate and stop vehicle 1, vehicle 1 will stop at or near the intersection, resulting in disruption of traffic flow at the intersection and the risk of contact or collision with other traffic participants. For example, if RMF is activated to decelerate vehicle 1 at a predetermined deceleration rate, but vehicle 1 is at a stage (point or time) where it is not possible to stop vehicle 1 before a no-stopping zone near an intersection, which will be described later, it is determined that RMF will operate near the intersection. In other words, if RMF is activated to decelerate vehicle 1 at a predetermined deceleration rate (for example, 4.0 m / s 2 ), a predetermined area before the intersection where the vehicle 1 will stop in a no-stop area can be defined as the vicinity of the intersection.

[0045] Note that even in the so-called "near an intersection," if the vehicle 1 is already traveling in a lane dedicated to turning right or left to follow the target route for automatic driving, or if automatic steering is occurring due to automatic driving, the vehicle may be excluded from the operation of RMF near an intersection, as described below. This is because changing the route for RMF when the vehicle is already preparing to turn right or left could increase the risk.

[0046] The setting of the target stop position for the RMF in the first embodiment will be described below.

[0047] [Setting target stop position for RMF] In the first embodiment, the target stop position for the RMF is set according to the following basic policy. (1) Reducing intersections with other traffic participants By setting multiple target stopping position candidates, intersections with other traffic participants are reduced. (2) Reducing the impact on traffic flow of other traffic participants By setting up a no-stopping area in a predetermined area around the intersection, including the intersection, the impact on the traffic flow of other traffic participants is reduced. (3) Determining the target stopping position by comparing risk factors The target stopping position is determined by comparing the risk factors of a plurality of target stopping position candidates.

[0048] The setting of the target stop position for the RMF will be described in detail below.

[0049] (1) Reducing intersections with other traffic participants The automatic driving device 10 is configured such that the environmental state estimation unit 11 acquires the vehicle position by matching the vehicle position information from the positioning means 24 with the map information in the map information database 23, and the RMF unit 12 constantly searches for multiple target stopping position candidates based on the vehicle position and surrounding map information during automatic driving in preparation for RMF activation.

[0050] When the RMF is activated near a crossroads intersection, the possible travel directions for the target route PA are going straight through the intersection, turning left, or turning right. As the target stop position candidates for the RMF, positions on a route different from the global route set by the automated driving device 10 may be set in consideration of reducing intersections with other traffic participants.

[0051] Therefore, the RMF unit 12 sets multiple target stop position candidates in areas that can be reached only by a route that goes straight through the intersection or a route that turns left, and does not set target stop position candidates on routes that turn right at the intersection.

[0052] (2) Reducing the impact on traffic flow of other traffic participants At intersections and their vicinity, no-stopping sections (no-stopping areas) A are set up, which are excluded from the search for target stopping position candidates. If vehicle 1 is stopped at an intersection or just before or just after it due to RMF activation, there is a possibility that the traffic flow of other traffic participants will be disrupted. Therefore, by setting up no-stopping sections A, the impact on the traffic flow of other traffic participants is reduced. Since no target stopping position candidates are set in no-stopping sections A, the no-stopping sections A can also be said to be a range that is excluded from the setting of target stopping positions.

[0053] An appropriate range is set for no stopping zone A to reduce the impact on the traffic flow of other traffic participants at the intersection. For example, the no stopping zone A at and near the intersection can be set to the area inside the edge of the intersection road, the area inside the stop line at an intersection with a stop line, the area within a specified distance (e.g., 6 meters) from the edge of the intersection road at an intersection without a stop line or a crosswalk, the area inside the crosswalk at an intersection without a stop line but with a crosswalk, or a no parking zone.

[0054] Note that no prohibited direction is set ahead in the traveling direction to be excluded from the search for target stop position candidates. That is, at a crossroads intersection, it is also possible to set a target stop position for RMF in the direction of a right turn, i.e., in the traveling direction in which the vehicle 1 needs to cross an oncoming lane.

[0055] (3) Determining the target stopping position by comparing risk factors Next, the determination of a target stop position by comparing risk factors of a plurality of target stop position candidates will be described.

[0056] As explained in (1) and (2) above, the RMF unit 12 sets multiple target stop position candidates in consideration of reducing intersections and reducing the impact on traffic flow. For each of the multiple set target stop position candidates, the RMF unit 12 calculates a risk factor RF that indicates the level of risk for the vehicle 1 from its current position to reach the target stop position candidate. The risk factor RF takes a larger value as the risk increases.

[0057] Specifically, the risk factor RF is calculated as the sum (Rf1+Rf2+Rf3) of point Rf1, which relates to the number of intersections between vehicle 1 and other traffic participants at and near the intersection, point Rf2, which relates to the predicted driving distance from vehicle 1's current position to each target stopping position candidate, and point Rf3, which relates to the predicted driving time from vehicle 1's current position to each target stopping position candidate.

[0058] The points Rf1 related to the number of intersections are calculated based on the number of intersections with other traffic participants on the route from the current position of vehicle 1 to the target stop position candidate, based on the viewpoint that the greater the number of intersections between vehicle 1 and other traffic participants, the higher the risk of contact or collision. For example, 10 points are added for one intersection, 20 points for two intersections, and 50 points for five intersections. For example, 10 points are added for each additional intersection. The number of intersections can be determined based on, for example, map information or external information acquired by the external sensor 21. In this embodiment, when the route of the vehicle 1 crosses a driving lane, it is determined that there is a possibility of an intersection with another vehicle, regardless of whether or not there is an actual vehicle, and the number of intersections is counted. Also, when the route of the vehicle 1 crosses a crosswalk, it is determined that there is a possibility of an intersection with a pedestrian, regardless of whether or not there is a pedestrian, and the number of intersections is counted. That is, the maximum number of intersections is counted based on the vehicle's position information obtained by the positioning means 24, such as the GNSS, and the route of the vehicle 1 acquired from the map information in the map information database 23 and road conditions.

[0059] The points Rf2 related to the predicted travel distance are calculated based on the predicted travel distance from the current position of vehicle 1 to the target stop position candidate, based on the viewpoint that the longer the distance until vehicle 1 stops, the higher the risk of contact or collision. For example, 0.5 points are added for a predicted travel distance of 10 meters, 1 point for 20 meters, and 2.5 points for 50 meters, and so on. For every 10 meters of the predicted travel distance, 0.5 points are added. The predicted travel distance can be estimated, for example, based on map information of the vehicle's position and the surrounding area.

[0060] The points Rf3 related to the predicted traveling time are calculated based on the predicted traveling time from the current position of vehicle 1 to the target stopping position candidate, based on the viewpoint that the longer it takes for vehicle 1 to stop, the higher the risk of contact or collision. One point is added for every 10 seconds of predicted traveling time, such as 1 point if the predicted traveling time is 10 seconds, 2 points if it is 20 seconds, and 5 points if it is 50 seconds. For example, but not limited to, the predicted traveling time may be calculated as follows: if vehicle 1 is traveling at a speed of 40 km / h and the RMF is activated, and the deceleration is 4.0 m / s 2 After decelerating to 10 km / h, the vehicle will continue to travel at a constant speed and then gradually decelerate (for example, deceleration of 1.96 m / s) just before reaching the target stop position candidate. 2 ) and stop at the target stop position candidate.

[0061] Note that the specific values ​​of the point Rf1 related to the number of intersections, the point Rf2 related to the predicted travel distance, and the point Rf3 related to the predicted travel time are merely examples, and it is of course possible to use values ​​other than those mentioned above. However, it is preferable to weight the points so that the weights increase in the order of the point Rf1 related to the number of intersections, the point Rf3 related to the predicted travel time, and the point Rf2 related to the predicted travel distance. This takes into consideration the fact that the greater the number of intersections where there is a possibility of intersection with other traffic participants, the higher the risk, and further that the longer the travel time until stopping at the target stop position, the greater the risk is thought to be compared to when the travel distance is long.

[0062] Furthermore, if the risk factors of multiple target stop position candidates have the same value, the target stop position S is selected in the following order of priority based on the direction of travel to the target stop position candidate: a direction going straight through the intersection, a direction in which the vehicle 1 turns at the intersection without crossing the oncoming lane, and a direction in which the vehicle 1 crosses the oncoming lane and turns at the intersection.

[0063] The RMF unit 12 compares the risk factors RF calculated for a plurality of target stop position candidates, and selects as the target stop position S the target stop position candidate with the smallest risk factor RF.

[0064] An example of selecting a target stop position S at an intersection C1, which is a crossroad without traffic lights, will be described with reference to Figure 5. In the example shown in Figure 5, in addition to vehicle 1 just before intersection C1, there may be vehicle 2 moving straight to the right, vehicle 3 moving straight to the left, and oncoming vehicle 4 moving straight around intersection C1. Crosswalks are provided on the road and intersecting roads that vehicle 1 passes through intersection C1. There may be pedestrians attempting to cross crosswalk D1 just before the intersection, pedestrians attempting to cross crosswalk D2 beyond the intersection, pedestrians attempting to cross crosswalk D3 where a left turn is to be made, and pedestrians attempting to cross crosswalk D4 where a right turn is to be made. The target route PA planned by automatic operation device 10 of vehicle 1 is a route PA that goes straight, turns left, or turns right through intersection C1.

[0065] 5, the RMF unit 12 sets a target stop position candidate T1 in a stop possible section B on the route going straight through the intersection C1, and sets a target stop position candidate T2 in a stop possible section B further ahead of the target stop position candidate T1. Also, it sets a target stop position candidate T3 in a stop possible section B on the route turning left at the intersection C1, and sets a target stop position candidate T4 in a stop possible section B on the route turning right at the intersection C1.

[0066] For target stop position candidate T1, there are four intersection points: an intersection point with vehicle 2 moving straight to the right in risk area RA1, an intersection point with vehicle 3 moving straight to the left in risk area RA2, an intersection point with a pedestrian attempting to cross crosswalk D1 in risk area RA3, and an intersection point with a pedestrian attempting to cross crosswalk D2 in risk area RA4. Therefore, the score Rf1 related to the number of intersection points is 40. If the predicted travel distance from the current position of vehicle 1 to target stop position candidate T1 is 100 meters and the predicted travel time is 33 seconds, the score Rf2 related to the predicted travel distance is 5 and the score Rf3 related to the predicted travel time is 3.3. In this case, the risk factor RF of target stop position candidate T1 is 48.3 (= Rf1 + Rf2 + Rf3).

[0067] As with target stop position candidate T1, target stop position candidate T2 has four intersection points: an intersection point with vehicle 2 moving straight to the right, an intersection point with vehicle 3 moving straight to the left, and an intersection point with pedestrians crossing crosswalks D1 and D2. Therefore, the score Rf1 related to the number of intersection points is 40. If the predicted travel distance from the current position of vehicle 1 to target stop position candidate T2 is 200 meters and the predicted travel time is 69 seconds, the score Rf2 related to the predicted travel distance is 10 and the score Rf3 related to the predicted travel time is 6.9. In this case, the risk factor RF of target stop position candidate T2 is 56.9 (= Rf1 + Rf2 + Rf3).

[0068] For target stop position candidate T3, there are three intersection points: an intersection with vehicle 2 moving straight to the right in risk area RA1, an intersection with a pedestrian attempting to cross crosswalk D1 in risk area RA3, and an intersection with a pedestrian attempting to cross crosswalk D3 in risk area RA5, so the point Rf1 related to the number of intersection points is 30. If the predicted travel distance from the current position of vehicle 1 to target stop position candidate T3 is 100 meters and the predicted travel time is 33 seconds, then the point Rf2 related to the predicted travel distance is 5 and the point Rf3 related to the predicted travel time is 3.3. In this case, the risk factor RF of target stop position candidate T1 is 38.3 (= Rf1 + Rf2 + Rf3).

[0069] For target stop position candidate T4, there are five intersection points: an intersection with vehicle 2 moving straight to the right in risk area RA1, an intersection with vehicle 3 moving straight to the left and an intersection with oncoming vehicle 4 in risk area RA6, an intersection with a pedestrian attempting to cross crosswalk D1 in risk area RA3, and an intersection with a pedestrian attempting to cross crosswalk D4 in risk area RA7, so the score Rf1 related to the number of intersection points is 50. If the predicted travel distance from the current position of vehicle 1 to target stop position candidate T4 is 100 meters and the predicted travel time is 33 seconds, then the score Rf2 related to the predicted travel distance is 5 and the score Rf3 related to the predicted travel time is 3.3. In this case, the risk factor RF of target stop position candidate T1 is 58.3 (= Rf1 + Rf2 + Rf3).

[0070] The RMF unit 12 compares the risk factors RF calculated for each of the plurality of target stop position candidates T1 to T4, and selects as the target stop position S the target stop position candidate T3 on the left turn route that has the smallest risk factor RF.

[0071] [Autonomous driving system override function] The cruise control system of the vehicle 1 has an override function that stops the automatic cruise by the automatic operation device 10 and transitions to a manual driving mode when an occupant or passenger of the vehicle 1 intervenes. That is, if a steering override is executed by an occupant or passenger during automatic cruise by the automatic operation device 10, the automatic steering control described above is stopped and the system transitions to a manual driving mode, allowing manual steering 34 (see FIG. 3). Furthermore, if an acceleration override is executed by an occupant or passenger during automatic cruise by the automatic operation device 10, or a deceleration override is executed by an occupant or passenger, the acceleration / deceleration control described above is stopped and the system transitions to a manual driving mode, allowing manual acceleration / deceleration operations 35, 36 (see FIG. 3). The manual steering operation 34 and the manual acceleration / deceleration operations 35, 36 can be detected, for example, by an internal sensor 22.

[0072] In principle, this type of override function can be executed even while the RMF is operating. However, if the RMF is activated near an intersection and a target stopping position is set that is on a route different from the global route to the destination, a panicked driver or passenger may perform a steering override or acceleration / deceleration override, creating a risk.

[0073] With reference to Figure 6, a risk situation due to override when RMF is activated near an intersection will be described. In the example shown in Figure 6, in addition to vehicle 1 just before intersection C1, there are vehicle 2 moving straight to the right and vehicle 4 moving straight on the opposite side around intersection C1, which is a crossroad without traffic lights. Crosswalks are provided on the road going straight through intersection C1 and on the intersecting road from vehicle 1, and there are pedestrians H1 and H2 about to cross crosswalk D1 and D2, respectively, where vehicle 1 will turn right. The target route PA planned by automatic operation device 10 of vehicle 1 is a route that turns right at intersection C1.

[0074] The RMF unit 12 sets a target stop position candidate T1 on the route going straight through the intersection C1, a target stop position candidate T2 on the route turning left, and a target stop position candidate T3 on the route turning right. For the target stop position candidate T1 on the route going straight, there is an intersection with the vehicle 2 moving straight to the right in the risk area RA1. For the target stop position candidate T2 on the route turning left, there is an intersection with the vehicle 2 moving straight to the right in the risk area RA1 and an intersection with the pedestrian H2 in the risk area RA3. Furthermore, for the target stop position candidate T3 on the route turning right, there is an intersection with the vehicle 2 moving straight to the right in the risk area RA1, an intersection with the oncoming vehicle 4 moving straight, and an intersection with the pedestrian H1 in the risk area RA2.

[0075] The RMF unit 12 calculates a risk factor RF for each of the target stop position candidates T1 to T3, and selects the target stop position candidate T1 on the straight route with the smallest risk factor RF as the target stop position S. In this case, since the target stop position S is located on the straight route PB, which is different from the right-turn route that is the target route PA for automated driving, if the RMF is activated near an intersection, the vehicle 1 will continue straight without turning right at the intersection C1. Since this behavior of the vehicle 1 differs from what the occupants or passengers had predicted, there is a possibility that the occupants or passengers in a panic will intervene by performing inappropriate steering operation or acceleration / deceleration operation.

[0076] If an inappropriate override while the RMF is in operation causes the vehicle's direction of travel to deviate from the target route PB for the RMF in the straight-ahead direction in the direction of a right turn, there is a risk of contact or collision with an oncoming vehicle 4 moving straight. In this way, if a lane change is made at an intersection by a steering override while the RMF is in operation, it may disrupt traffic flow and induce contact or collision with other traffic participants. In addition, if acceleration or deceleration is made at an intersection by an acceleration / deceleration override while the RMF is in operation, it may also disrupt traffic flow and induce contact or collision with other traffic participants.

[0077] Therefore, in the first embodiment, when RMF is activated near an intersection, the override threshold, which is the criterion for determining whether an occupant or passenger intervenes in the operation, is changed to a value greater than the override threshold when RMF is not activated. This makes it less likely that an override will be executed even if an occupant or passenger intervenes in the steering operation or acceleration / deceleration operation while RMF is activated. As a result, as shown in FIG. 7, even if an occupant or passenger intervenes in the steering operation or acceleration / deceleration operation while RMF is activated, the vehicle 1 can be guided to the target stop position S in the straight direction and stopped without deviating from the target path PB for RMF. Since there is no need to change course or accelerate or decelerate at an intersection, it is possible to reduce disruption of traffic flow and the risk of contact or collision with other traffic participants.

[0078] [Setting the override threshold when RMF is activated] As described above, when the RMF is operating near an intersection, the override threshold serving as the criterion for determining operation intervention by the driver or passenger is set to a value greater than the override threshold when the RMF is not operating (normal condition). Regarding acceleration / deceleration operation intervention, the acceleration override threshold OEr when the RMF is operating is set to a value greater than the acceleration override threshold OEd when the RMF is not operating (OEd < OEr), and the deceleration override threshold OPr when the RMF is operating is set to a value greater than the deceleration override threshold OPd when the RMF is not operating (OPd < OPr).

[0079] Regarding steering operation intervention, the right steering override threshold OTrr and the left steering override threshold OTrl when the RMF is operating are each set to a value greater than the right steering override threshold OTdr and the left steering override threshold OTdl when the RMF is not operating (OTdr = OTdl < OTrr, OTdr = OTdl < OTrl). Furthermore, the magnitude relationship between the right steering override threshold OTrr and the left steering override threshold OTrl when the RMF is operating is set according to the pattern of the route change due to RMF operation.

[0080] Hereinafter, referring to FIGS.

[0081] 8(a) to

[0081] 8(d), the setting of the steering override threshold according to the route change pattern when the RMF is operating will be described.

[0081] As shown in FIG.

[0081] 8(a), when the target route PA of the automatic driving is in the right turn direction and the target route for the RMF is the straight-ahead route PB1 or the left turn route PB2, it is assumed that a rightward steering operation intervention is performed to follow the target route PA. Therefore, the right steering override threshold OTrr when the RMF is operating is set to a value greater than the left steering override threshold OTrl (OTrl < OTrr) so as to avoid an override due to a sudden right steering by the driver or passenger.

[0082] As shown in Figure 8(b), when the target route PA for autonomous driving is a left turn and the target route for RMF is a straight route PB1 or a right turn route PB2, it is assumed that left steering operation intervention will be performed to follow the target route PA. Therefore, to avoid override by sudden left steering by the driver or passenger, the left steering override threshold OTrl when RMF is activated is set to a value larger than the right steering override threshold OTrr (OTrr <OTrl)。

[0083] As shown in Figure 8(c), when the target route PA for autonomous driving is a straight-ahead direction and the target route for RMF is a route PB in a right-turn direction, it is assumed that left steering operation intervention will be performed to follow the target route PA. Therefore, to avoid override by sudden left steering by the driver or passenger, the left steering override threshold OTrl when RMF is activated is set to a value larger than the right steering override threshold OTrr (OTrr <OTrl)。

[0084] As shown in Figure 8(d), when the target route PA for autonomous driving is a straight-ahead direction and the target route for RMF is a route PB in a left-turn direction, it is assumed that a right-hand steering operation intervention will be performed to follow the target route PA. Therefore, to avoid an override by a sudden right-hand steering by a driver or passenger, the right-hand steering override threshold OTrr when RMF is activated is set to a value larger than the left-hand steering override threshold OTrl (OTrl <OTrr)。

[0085] [RMF operation flow during autonomous driving] Next, the flow of RMF operation when a situation arises in which remote monitoring and operation is difficult during autonomous driving will be described. Fig. 9 shows a flowchart illustrating the flow of RMF operation according to the first embodiment.

[0086] (1) Automatic driving operation by remote monitoring and operation (Step S100) In response to a start command from the operator of the remote control base station 25R, automatic traveling is performed by the automatic traveling device 10. The automatic traveling device 10 controls the traveling of the vehicle 1 in accordance with the generated target route and target vehicle speed.

[0087] (2) Setting multiple target stop position candidates (step S101) The RMF unit 12 searches for target stop position candidates based on the vehicle's own position information from the positioning means 24 and the map information in the map information database 23, and sets multiple target stop position candidates along the global route to the destination in preparation for RMF activation. The RMF unit 12 sets multiple target stop position candidates at all times (for example, at predetermined intervals) during automated driving, not just near intersections. The multiple target stop position candidates are constantly updated, and the latest target stop position candidates based on the current position of the vehicle 1 are set.

[0088] (3) Communication failure determination (step S110) During operation of the automatic operation device 10 by remote monitoring and operation, the RMF unit 12 constantly (for example, at predetermined intervals) determines whether communication with the remote control base station 25R via the communication device 25 is normal and whether automatic driving can be continued. If it is determined that a communication failure such as a failure of the communication device 25 or a cutoff in communication with the remote control base station 25R has made it difficult to continue remote monitoring and operation of automatic driving by the automatic operation device 10, the process proceeds to step S111 to activate the RMF. On the other hand, if no communication failure has occurred and remote monitoring and operation can be continued, the process returns to step S101 and automatic driving continues.

[0089] (4) Remote monitoring and operation stop (steps S111 to S113) If it is determined that it has become difficult to continue remote monitoring and operation, a flag indicating a communication failure is set (step S111), and at the same time, the alarm unit 17 notifies those inside and outside the vehicle that the operation (automatic driving) of the automatic operation device 10 through remote monitoring and operation will be stopped (step S112), and the operation of the automatic operation device 10 through remote monitoring and operation will be stopped.

[0090] (5) RMF operation notification (step S120) When the RMF is activated due to a situation where it is difficult to continue remote monitoring and operation, the notification unit 17 notifies the crew and passengers of the vehicle 1. The notification unit 17 may also be configured to notify the outside of the vehicle.

[0091] (6) Selecting a target stop position (step S125) A target stop position S is selected from a plurality of target stop position candidates. The RMF unit 12 calculates the risk factor RF for each of the plurality of target stop position candidates set in step S101 as described above, and selects the target stop position candidate with the lowest risk factor RF as the target stop position S. The route generation unit 13 generates a target route for RMF operation to the selected target stop position S based on the host vehicle position information, map information, adjacent lane marking positions, other vehicle positions and speeds, the vehicle motion state, etc. acquired by the environmental state estimation unit 11.

[0092] If the target route for RMF operation differs from the target route for automatic driving, the notification unit 17 also notifies the crew and passengers of the vehicle 1 that the route will be changed due to RMF operation.

[0093] (7) Change the override threshold (step S126) The right steering override threshold OTdr and left steering override threshold OTdl under normal circumstances are changed to the right steering override threshold OTrr and left steering override threshold OTrl when RMF is activated, depending on the pattern of lane changes due to RMF activation. Note that if lane changes do not occur due to RMF activation, it is considered unlikely that a panicked crew member or passenger will intervene in the steering operation, so the steering override thresholds are not changed, and the right steering override threshold OTdr and left steering override threshold OTdl when RMF is not activated (normally) are used as they are.

[0094] In addition, the acceleration override threshold OEd and deceleration override threshold OPd in ​​normal operation are changed to the acceleration override threshold OEr and deceleration override threshold OPr in RMF operation, respectively.

[0095] (8) RMF operation (step S127) The RMF starts operating to safely stop vehicle 1 within the target stopping area. The RMF is a function that drives vehicle 1 under its own power to the target stopping position S according to the target route for RMF operation, and then decelerates and stops it.

[0096] (9) Determining whether or not the vehicle can stop at the target stop position S (step S128) The RMF unit 12 detects the presence or absence of obstacles around the target stopping position S based on obstacle information around the target stopping position S provided from the external sensor 21 via the environmental state estimation unit 11, and determines whether or not it is possible to stop at the target stopping position S. If no obstacles are present around the target stopping position S, it determines that stopping is possible and proceeds to step S130.

[0097] On the other hand, for example, if there is another vehicle at the target stopping position S or if construction work is being carried out near the target stopping position S, it is determined that the vehicle 1 cannot stop at the target stopping position S due to obstacles around the target stopping position S. In this case, the process returns to step S125 and a new target stopping position S is selected.

[0098] (10) Deceleration and Stopping by RMF (Steps S130 to S132) The automatic operation device 10 activates a direction indicator (not shown) in the direction of the target stop position S (step S130). The vehicle control unit 14 performs speed control and steering control so that the vehicle 1 travels while decelerating according to the target route for RMF operation, and stops the vehicle at the target stop position S (step S131). The automatic operation device 10 flashes hazard lights (not shown) (step S132).

[0099] (11) RMF Completion Determination (Steps S133 to S134) The RMF unit 12 matches the position where the vehicle 1 has stopped with the target stop position S based on the vehicle position information and map information, and determines whether they match. If they do not match, the process returns to step S131 and the vehicle travels to the target stop position S. If the stop position of the vehicle 1 matches the target stop position S, the process determines that the RMF has been completed, and proceeds to step S134, where the RMF is stopped. This ends the series of RMF processes.

[0100] The cruise control device for the vehicle 1 according to the first embodiment described above can achieve the following advantageous effects.

[0101] The cruise control device of the vehicle 1 equipped with the automatic operation device 10 for performing automatic driving through remote monitoring and operation has a risk mitigation function (RMF) that performs risk mitigation control to stop the vehicle 1 at a target stopping position when it becomes difficult to continue remote monitoring and operation, and an override function that stops automatic driving by the automatic operation device 10 and switches to manual driving mode through operational intervention by a driver or passenger of the vehicle 1. The automatic operation device 10 is configured to search for multiple target stopping position candidates based on the position information and map information of the vehicle 1 in preparation for RMF activation during automatic driving, and when RMF activates near an intersection, if a target stopping position candidate located on a route different from the target route PA of the automatic driving is selected as the target stopping position S from the multiple target stopping position candidates, change the override threshold, which is the criterion for determining operational intervention by the driver or passenger, to a value larger than the override threshold when the RMF is not activated.

[0102] When a communication failure occurs near an intersection making it difficult to remotely monitor and operate the automatic operation device 10 and the RMF is activated, the override threshold, which is the criterion for determining whether to intervene, can be changed to a value greater than the override threshold when the RMF is not activated, thereby preventing override by panicked crew members or passengers due to the activation of the RMF.

[0103] The override thresholds include steering override thresholds that are criteria for determining whether to intervene in a steering operation, and the steering override thresholds OTrr and OTrl when the RMF is activated near an intersection are such that the steering override threshold in the direction to turn at the intersection along the target route is greater than the steering override threshold in the opposite direction to the direction to turn at the intersection along the target route. This makes it possible to reduce the risk of disruption of traffic flow and contact or collision with other traffic participants due to steering override by panicked occupants or passengers when the RMF is activated and the vehicle 1 proceeds in a direction different from the original destination of the automated driving.

[0104] The override thresholds include an acceleration override threshold that serves as a criterion for determining whether to intervene in an acceleration operation, and when the RMF is activated, if the steering override thresholds OTdr, OTdl when the RMF is not activated are changed to the steering override thresholds OTrr, OTrl when the RMF is activated, the acceleration override threshold is set to a value OEr that is larger than the acceleration override threshold OEd when the RMF is not activated. By increasing the acceleration override threshold in conjunction with a change in the steering override threshold, it is possible to prevent a sudden acceleration override by a panicked occupant or passenger, and it is possible to improve driving safety when the RMF is activated and allow the vehicle 1 to reach the target stopping position.

[0105] The override thresholds include a deceleration override threshold that is a criterion for determining whether to intervene in a deceleration operation, and when the RMF is activated, if the steering override thresholds OTdr, OTdl when the RMF is not activated are changed to the steering override thresholds OTrr, OTrl when the RMF is activated, the deceleration override threshold is set to a value OPr that is larger than the deceleration override threshold OPd when the RMF is not activated. By increasing the deceleration override threshold in conjunction with a change in the steering override threshold, it is possible to prevent a sudden deceleration override by a panicked crew member or passenger, and it is possible to improve driving safety when the RMF is activated and allow the vehicle 1 to reach the target stopping position.

[0106] When the RMF is operating, the acceleration override threshold OEr is set to a value larger than the deceleration override threshold OPr during RMF operation. If an acceleration override occurs due to a panicked driver or passenger, it may result in sudden acceleration while turning at an intersection. Therefore, by setting the acceleration override threshold OEr to a value larger than the deceleration override threshold OPr, it becomes difficult for an acceleration override to occur, enhancing the driving safety during RMF operation and enabling the vehicle 1 to reach the target stop position.

[0107] -Variation of the First Embodiment- In the first embodiment described above, when the RMF is operating near an intersection, the override threshold serving as the criterion for determining operation intervention by the driver or passenger is set to a value larger than the override threshold during non-RMF operation (normal operation). In addition to this, the override threshold during RMF operation may be set to different values before and after the steering by the RMF at the intersection.

[0108] A specific setting method will be described below. The steering override thresholds OTrr and OTrl during RMF operation include the first RMF steering override thresholds OTrr1 and OTrl1, and the second RMF steering override thresholds OTrr2 and OTrl2 that are larger than the first RMF steering override thresholds OTrr1 and OTrl1 (OTrr1 < OTrr2, OTrl1 < OTrl2). The acceleration override threshold OEr during RMF operation includes the first RMF acceleration override threshold OEr1 and the second RMF acceleration override threshold OEr2 that is larger than the first RMF acceleration override threshold OEr1 (OEr1 < OEr2). The deceleration override threshold OPr during RMF operation includes the first RMF deceleration override threshold OPr1 and the second RMF deceleration override threshold OPr2 that is larger than the first RMF deceleration override threshold OPr1 (OPr1 < OPr2).

[0109] From the time when the RMF is activated near an intersection until before steering by the RMF occurs at the intersection, first RMF steering override thresholds OTrr1, OTrl1, first RMF acceleration override threshold OEr1, and first RMF deceleration override threshold OPr1 are set. After steering by the RMF occurs at the intersection, the first RMF steering override thresholds OTrr1, OTrl1, first RMF acceleration override threshold OEr1, and first RMF deceleration override threshold OPr1 are changed to second RMF steering override thresholds OTrr2, OTrl2, second RMF acceleration override threshold OEr2, and second RMF deceleration override threshold OPr2.

[0110] After steering occurs due to RMF activation, the steering override threshold, acceleration override threshold, and deceleration override threshold are set to large values ​​(OTrr2, OTrl2, OEr2, OPr2) to prevent override due to panicked crew or passenger intervention. On the other hand, before steering to change direction at an intersection when RMF is activated (for example, before the intersection edge), the steering override threshold, acceleration override threshold, and deceleration override threshold are set to small values ​​(OTrr1, OTrl1, OEr1, OPr1). This allows the manager in the driver's seat of vehicle 1 to perform evacuation operations at his or her discretion when it is determined that the time required to reach the target stopping position will be extended due to congestion, etc. Note that this manager is normally not involved in driving vehicle 1 and is only in the car to respond to emergencies, and it is assumed that the manager will use the evacuation operations to evacuate vehicle 1 to a parking lot of a facility directly next to it.

[0111] -Second embodiment- A second embodiment of the present invention will be described below with reference to the drawings. The basic configuration of a vehicle cruise control system according to the second embodiment is the same as that of the first embodiment described above. Differences from the first embodiment will be mainly described below. In the second embodiment, a target stop position S for RMF is determined based on real-time information about the surroundings of the vehicle acquired using V2X communication technology or the like.

[0112] 10 schematically illustrates a cruise control system for a vehicle 100 according to the second embodiment. The cruise control system for a vehicle 100 according to the second embodiment further includes a V2X unit 26 that receives sensing information about the surroundings of the vehicle via V2X communication 26R.

[0113] V2X (Vehicle to Everything) is a wireless communication technology that connects vehicles with everything, and is a general term for communication between vehicles (V2V: Vehicle to Vehicle), communication between vehicles and roadside infrastructure (V2I: Vehicle to Infrastructure), communication between vehicles and pedestrians (V2P: Vehicle to Pedestrian), and communication between vehicles and networks (V2N: Vehicle to Network).

[0114] The V2X unit 26 is configured to receive other vehicle information from other vehicles via V2V, receive traffic information (e.g., traffic congestion information, road construction information, etc.) from roadside devices via V2I, detect the presence or absence of pedestrians or bicycles with smartphones via V2P, and receive map information and the like from an external server (not shown) via V2N. In this embodiment, the V2X unit 26 is configured to acquire, as sensing information around the vehicle itself, information on the presence or absence of other traffic participants (other vehicles, pedestrians, bicycles, etc.) around intersections in particular. The sensing information around the vehicle 100 received by the V2X unit 26 is input to the environmental state estimation unit 11.

[0115] The RMF unit 12 determines a target stopping position when the RMF is activated, taking into consideration real-time information on the presence or absence of other traffic participants around the intersection, which is input from the V2X unit 26 via the environmental state estimation unit 11. Note that for intersections with good visibility in suburban areas, information on the presence or absence of other traffic participants (other vehicles, pedestrians, bicycles, etc.) around the intersection can also be obtained from image data from the camera (on-board camera) 212 as sensing information around the vehicle.

[0116] In the second embodiment, real-time information regarding the presence or absence of other traffic participants around the intersection, acquired by the V2X unit 26 or the on-board camera 212, is reflected in the calculation of the point Rf1 regarding the number of intersections. That is, of the maximum number of risk areas based on the vehicle position information obtained by the positioning means 24, such as GNSS, and the road structure acquired from the map information in the map information database 23, only risk areas where the presence of other traffic participants is detected are counted as the number of intersections. Here, with regard to pedestrians near the intersection, the presence or absence of pedestrians approaching the intersection, waiting at the intersection, or crossing the crosswalk at the intersection is detected from the sensing information. Pedestrians leaving the intersection, even if they are near the intersection, are determined to have no possibility of intersecting with the vehicle 100, and are not counted as part of the number of intersections.

[0117] Selection of a target stop position S at an intersection C1, which is a crossroad without traffic lights, will be described with reference to Fig. 11. In the example shown in Fig. 11, a vehicle 100 is present just before the intersection C1, and a crosswalk is provided on the road going straight through the intersection C1 as seen from the vehicle 100 and on the intersecting road. Sensing information from the V2X unit 26 and / or the on-board camera 212 detects that there are no other vehicles about to enter the intersection C1 in the vicinity of the intersection C1, and further detects the presence of a pedestrian H1 about to cross crosswalk D1 ahead of the intersection C1, and a pedestrian H2 about to cross crosswalk D2 ahead of the intersection C1. The target route PA planned by the automatic operation device 10 of the vehicle 1 is a route PA that goes straight, turns left, or turns right through the intersection C1.

[0118] 11, the RMF unit 12 sets a target stop position candidate T1 in a stop possible section B on the route going straight through the intersection C1, and sets a target stop position candidate T2 in a stop possible section B further ahead of the target stop position candidate T1. Also, it sets a target stop position candidate T3 in a stop possible section B on the route turning left at the intersection C1, and sets a target stop position candidate T4 in a stop possible section B on the route turning right at the intersection C1.

[0119] For the target stop position candidate T1, the number of intersections is one, an intersection with a pedestrian H1 beyond the intersection C1 in the risk area RA1. Because sensing information from the V2X unit 26 and / or the in-vehicle camera 212 detects that there are no other vehicles entering the intersection C1 in the vicinity of the intersection C1, the number of intersections with other vehicles is zero. Therefore, the score Rf1 related to the number of intersections is 10. If the predicted travel distance from the current position of vehicle 1 to the target stop position candidate T1 is 100 meters and the predicted travel time is 33 seconds, the score Rf2 related to the predicted travel distance is 5 and the score Rf3 related to the predicted travel time is 3.3. In this case, the risk factor RF of the target stop position candidate T1 is 18.3 (= Rf1 + Rf2 + Rf3).

[0120] As with target stop position candidate T1, the number of intersections for target stop position candidate T2 is one, with pedestrian H1 beyond intersection C1 in risk area RA1. Therefore, the point Rf1 related to the number of intersections is 10. If the predicted travel distance from the current position of vehicle 1 to target stop position candidate T2 is 200 meters and the predicted travel time is 69 seconds, the point Rf2 related to the predicted travel distance is 10 and the point Rf3 related to the predicted travel time is 6.9. In this case, the risk factor RF of target stop position candidate T2 is 26.9 (= Rf1 + Rf2 + Rf3).

[0121] For target stop position candidate T3, the number of intersections is one, with pedestrian H2 at the left turn destination in risk area RA2, and the point related to the number of intersections is Rf1 = 10. If the predicted travel distance from the current position of vehicle 1 to target stop position candidate T3 is 100 meters and the predicted travel time is 33 seconds, the point related to the predicted travel distance is Rf2 = 5 and the point related to the predicted travel time is Rf3 = 3.3. In this case, the risk factor RF of target stop position candidate T1 is 18.3 (= Rf1 + Rf2 + Rf3).

[0122] For target stop position candidate T4, the maximum number of intersections is five when not taking into account sensing information from the V2X unit 26 and / or the onboard camera 212. Specifically, there may be an intersection with a vehicle 2 moving straight to the right, an intersection with a vehicle 3 moving straight to the left, an intersection with an oncoming vehicle 4 moving straight, an intersection with a pedestrian crossing the crosswalk just before intersection C1, and an intersection with a pedestrian crossing the crosswalk after turning right.

[0123] 11, however, the number of intersections is zero because the sensing information from the V2X unit 26 and / or the in-vehicle camera 212 detects that there are no other traffic participants in the right-turn direction. Therefore, the point Rf1 regarding the number of intersections is calculated as Rf1=0.

[0124] If the predicted travel distance from the current position of the vehicle 100 to the target stop position candidate T4 is 100 meters and the predicted travel time is 33 seconds, then the point Rf2 for the predicted travel distance is 5 and the point Rf3 for the predicted travel time is 3.3. In this case, the risk factor RF of the target stop position candidate T1 is 8.3 (=Rf1+Rf2+Rf3).

[0125] The RMF unit 12 compares the risk factors RF calculated for each of the plurality of target stop position candidates T1 to T4, and selects as the target stop position S the target stop position candidate T4 on the right turn route that has the smallest risk factor RF.

[0126] If a situation arises during automatic driving where remote monitoring and operation are difficult, the automatic driving device 10 activates the RMF in accordance with the flowchart of Fig. 9, as in the first embodiment described above, and causes the vehicle 100 to automatically drive to and stop at the target stop position S. When the RMF is activated, the override threshold is changed from the override threshold when the RMF is not activated (normally) to the override threshold when the RMF is activated, as in the first embodiment described above.

[0127] As described above, since a search for multiple target stop position candidates is executed during automated driving, target stop position S can be selected promptly when RMF operation starts. When RMF operates near an intersection, the presence or absence of pedestrians near the intersection can be grasped in real time and reflected in the number of intersection points based on sensing information acquired by V2X communications 26, 26R in urban areas and cities, and sensing information acquired from images by on-board camera 212 in intersections with good visibility in suburban areas. This makes it possible to select, as target stop position S, a target stop position candidate that minimizes the number of intersections with pedestrians, thereby minimizing the risk of disrupting traffic flow and inducing contact or collision with other traffic participants.

[0128] Furthermore, pedestrians detected by V2X communications 26, 26R and / or on-board camera 212 may be approaching an intersection, waiting at an intersection, or crossing a crosswalk at the intersection. By not counting pedestrians leaving an intersection as part of the number of intersection points, the number of intersection points at which pedestrians may cross can be accurately determined.

[0129] The system is configured to obtain information on the presence or absence of pedestrians at the intersection as well as information on other vehicles approaching the intersection using V2X communications 26, 26R and / or on-board camera 212, and based on the pedestrian detection information and information on the other vehicles, select, from among multiple target stopping position candidates, a target stopping position candidate that minimizes the number of intersections between vehicle 100, pedestrians, and other vehicles and that allows vehicle 100 to stop, as target stopping position S. By obtaining information on not only pedestrians near the intersection but also other vehicles approaching the intersection in real time, it is possible to further reduce the risk of disrupting traffic flow and inducing contact or collision with other traffic participants.

[0130] After selecting the target stop position, information about the vicinity of the target stop position S is continuously acquired by V2X communications 26, 26R and / or the on-board camera 212, and if an obstacle is detected on the route to the target stop position S, a target stop position candidate located on another route is selected as the new target stop position S. If there is an obstacle on the route to the target stop position S, such as congestion, waiting at a railroad crossing, or the presence of another vehicle at the target stop position, it is expected that the time required to reach the target stop position S will be extended. In such a case, by switching to a target stop position S on another route, it is possible to quickly reach the target stop position S and stop the vehicle.

[0131] -Variations- (1) In the above-described embodiment, when the RMF is activated near an intersection, the override threshold is changed so that an override due to operation intervention by a vehicle occupant or passenger is less likely to occur. However, this is not limited to when the RMF is activated near an intersection, and the override threshold may be changed in a similar manner to the above-described embodiment in situations where the RMF activation is required to change lanes or directions, such as on multi-lane roads. Furthermore, in the above-described embodiment, the intersection is a crossroads, but the present invention can also be applied to intersections where the intersection is a T-junction or a five-way intersection.

[0132] (2) In the above-described embodiment, in preparation for RMF activation, a plurality of target stop position candidates are constantly searched for, and the target stop position S is selected from the plurality of target stop position candidates. Since it is anticipated that an obstacle may exist around the target stop position S, making it impossible to stop, it is preferable to have a large number of target stop position candidates. From the viewpoint of the processing load on the RMF unit 12, the number of target stop position candidates may be set to at least two, and if it is impossible to stop at the selected target stop position S, a target stop position candidate located on the same route may be added.

[0133] (3) In the above-described embodiment, the determination of the target stop position S when the RMF is activated near an intersection has been described. However, the method for determining the target stop position S according to the above-described embodiment can be applied not only to the vicinity of an intersection but also to situations where the activation of the RMF requires a lane change or a course change, such as on a multi-lane road.

[0134] (4) In the above-described embodiment, the risk factor RF is calculated as the sum of the point Rf1 related to the number of intersections, the point Rf2 related to the predicted travel distance, and the point Rf3 related to the predicted travel time. However, this is not limited to this, and the risk factor RF may be calculated using at least one of the point Rf1 related to the number of intersections, the point Rf2 related to the predicted travel distance, and the point Rf3 related to the predicted travel time. Furthermore, the risk factor RF may be calculated based on factors other than the number of intersections, the predicted travel distance, and the predicted travel time.

[0135] (5) In the above-described embodiment, the traffic rule is to keep to the left, but this embodiment can also be applied to cases where the traffic rule is to keep to the right. In cases where the traffic rule is to keep to the right, turning right at an intersection means turning in a direction that does not cross the oncoming lane, and turning left at an intersection means turning in a direction that crosses the oncoming lane.

[0136] (6) In the above-described embodiment, a no-stop section (no-stop area) A in which no target stop position is set is provided at the intersection and its vicinity. In addition, a no-stop direction in which no target stop position is set ahead of the traveling direction may be set at the intersection. For example, a traveling direction in which the vehicle 1 must cross an oncoming lane may be set as a no-stop direction. Specifically, at a three-way intersection (T-junction) and a four-way intersection (crossroads), a right-turn direction may be set as a no-stop direction, and at a five-way intersection, a right-turn direction and a right-turn or left-turn direction with an intersection angle of more than 90 degrees may be set as a no-stop direction. Because no target stop position is set in a no-stop direction, the no-stop direction can also be said to be a traveling direction that is excluded from the search for target stop position candidates.

[0137] (7) In the second embodiment described above, information regarding the presence or absence of pedestrians around the intersection is acquired using sensing information from the V2X communications 26, 26R and the in-vehicle camera 212. In this case, in addition to the presence or absence of pedestrians, the number of pedestrians may also be detected, and if pedestrians are present, the score Rf1 related to the number of intersection points may be calculated based on the number of pedestrians. For example, the greater the number of pedestrians, the greater the value of the score Rf1 related to the number of intersection points.

[0138] (8) In the second embodiment described above, the driving control system of the vehicle 100 is configured to use sensing information from both the V2X communications 26, 26R and the on-board camera 212. However, this is not limited thereto, and the driving control system may be configured to use sensing information from at least one of the V2X communications 26, 26R and the on-board camera 212.

[0139] Although several embodiments of the present invention have been described above, it should be noted that the present invention is not limited to the above-described embodiments, and various modifications and variations are possible within the scope of the present invention. [Explanation of symbols]

[0140] 1,100 vehicles 10 Automatic operation device 11 Environmental state estimation unit 12 RMF section 13 Route generation unit 14 Vehicle control unit 15 ACC controller 16 Autopilot Controller 17. Information Department 21 External Sensor 22 Internal Sensors 23 Map Information Database 24 Positioning Method (GNSS) 25 Communication Device 26 V2X units 31 EPS controller 32 Engine Controller 33 ESP / ABS controller 34 Manual steering (handle) 35 Manual operation (accelerator pedal) 36 Manual operation (brake pedal)

Claims

1. A vehicle driving control device equipped with an automatic driving device for performing automatic driving by remote monitoring and operation, A risk mitigation function (RMF) that executes risk mitigation control to stop the vehicle at a target stopping position when it becomes difficult to continue remote monitoring and operation; An override function that stops automatic driving by the automatic driving device and switches to manual driving mode by operational intervention of a vehicle occupant or passenger; In those having The automatic operation device is During the automatic driving, a search for a plurality of target stopping position candidates is always performed based on the position information and map information of the vehicle in preparation for the activation of the RMF; A vehicle driving control device configured to change an override threshold, which is a criterion for determining whether the occupant or passenger should intervene, to a value greater than the override threshold when the RMF is not activated, when a target stop position candidate located on a route different from the target route of the automatic driving is selected as the target stop position from among the plurality of target stop position candidates when the RMF is activated near an intersection.

2. the override threshold includes a steering override threshold that is a criterion for determining whether to intervene in a steering operation, 2. The vehicle cruise control device according to claim 1, wherein the steering override threshold when the RMF is activated near the intersection is such that the steering override threshold in a direction to turn through the intersection along the target route is greater than the steering override threshold in a direction opposite to the direction to turn through the intersection along the target route.

3. The override threshold includes an acceleration override threshold that is a criterion for determining whether to intervene in an acceleration operation, 3. The vehicle driving control device according to claim 2, wherein, when the RMF is activated, if the steering override threshold is changed from the steering override threshold when the RMF is not activated to the steering override threshold when the RMF is activated, the acceleration override threshold is set to a value greater than the acceleration override threshold when the RMF is not activated.

4. The override threshold includes a deceleration override threshold that is a criterion for determining whether to intervene in a deceleration operation, 4. The vehicle driving control device according to claim 3, wherein, when the RMF is activated, if the steering override threshold is changed from the steering override threshold when the RMF is not activated to the steering override threshold when the RMF is activated, the deceleration override threshold is set to a value greater than the deceleration override threshold when the RMF is not activated.

5. The vehicle cruise control device according to claim 4 , wherein the acceleration override threshold when the RMF is activated is set to a value greater than the deceleration override threshold when the RMF is activated.

6. the steering override threshold during activation of the RMF includes a first RMF steering override threshold and a second RMF steering override threshold greater than the first RMF steering override threshold; the acceleration override threshold during activation of the RMF includes a first RMF acceleration override threshold and a second RMF acceleration override threshold greater than the first RMF acceleration override threshold; the deceleration override threshold during activation of the RMF includes a first RMF deceleration override threshold and a second RMF deceleration override threshold greater than the first RMF deceleration override threshold; setting the first RMF steering override threshold, the first RMF acceleration override threshold, and the first RMF deceleration override threshold from the time of activation of the RMF near the intersection to the time before steering occurs at the intersection; 6. The vehicle cruise control device according to claim 5, wherein after steering occurs at the intersection, the first RMF steering override threshold, the first RMF acceleration override threshold, and the first RMF deceleration override threshold are changed to the second RMF steering override threshold, the second RMF acceleration override threshold, and the second RMF deceleration override threshold.

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