Travel control device for vehicle

Abstract

To reduce disturbance of traffic flow at an annular intersection and the risk of contact or collision with other traffic participants when a risk mitigation function is activated.SOLUTION: An autonomous driving device having a risk mitigation function RMF, which executes risk mitigation control to stop a vehicle 1 at a target stop position in a situation where it becomes difficult to continue autonomous driving by remote monitoring or remote operation, is configured to search for candidate target stop positions on the basis of position information of the vehicle 1 and map information in preparation for activation of the RMF during autonomous driving, set a plurality of candidate target stop positions T21-T42 including the candidate target stop position located on a route different from the target route of autonomous driving, set the candidate target stop positions T21-T42 outside an annular intersection RA when the annular intersection RA exists on the target route, and select the target stop position from among the plurality of candidate target stop positions T21-T42 when the RMF is activated near the annular intersection RA or within the annular intersection RA.SELECTED DRAWING: Figure 4

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 that is driving automatically through remote monitoring and remote operation. [Background technology]

[0002] Technology is being developed to operate unmanned vehicles under specific conditions using remotely monitored and remotely controlled automated driving devices. Remotely controlled automated driving systems are configured to monitor the driving of a vehicle operated by an automated driving device equipped with, for example, an Accelerator Control System (ACCS) or a continuous automatic steering system from a remote control base station and operate the vehicle as necessary. In such remotely controlled automated driving systems, if for some reason it becomes difficult to continue automated driving using remote monitoring and remote control 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] Incidentally, a roundabout is known as a type of intersection installed on roads. A roundabout is a type of intersection that connects multiple roads via a circular space, and is configured so that vehicles travel in one direction around a circular road around a central island in the center of the circular space. Generally, the circular road at a roundabout is not equipped with stop signs or traffic lights. As such, because a roundabout is different in form from a normal intersection, when a risk mitigation function is activated near or within the roundabout, it is desirable to safely guide vehicles to an evacuation area so as to avoid disrupting traffic flow or contact or collision with other traffic participants within or near the roundabout.

[0006] The present invention has been made in consideration of the above-mentioned circumstances, and its purpose is to reduce the risk of traffic flow disruption and contact / collision with other traffic participants when a risk mitigation function is activated near or within a roundabout. [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 through remote monitoring and remote operation, which 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 automatic driving through remote monitoring and remote operation.The automatic driving device is configured to, during the automatic driving, in preparation for the activation of the RMF, search for target stopping position candidates based on the vehicle's position information and map information, set multiple target stopping position candidates including target stopping position candidates located on a route different from the target route of the automatic driving, and if a roundabout is present on the target route, set a target stopping position candidate outside the roundabout, and when the RMF is activated near or within the roundabout, select a target stopping position from the multiple target stopping position candidates. [Effects of the Invention]

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

[0009] [Figure 1] FIG. 1 is a schematic diagram showing a vehicle driving control device according to one 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 device. [Figure 4] FIG. 4 is a diagram showing a plurality of target stop position candidates that are set in preparation for the case where RMF is activated near or within a roundabout. [Figure 5] FIG. 5 is a table showing an example of the priorities of a plurality of target stop position candidates. [Figure 6] FIG. 6 is a flowchart illustrating the flow of the RMF operation. DETAILED DESCRIPTION OF THE INVENTION

[0010] An embodiment of the present invention will be described in detail below with reference to the drawings. A cruise control device for a vehicle 1 according to this 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 device for the vehicle 1 is a remote-controlled automated driving system capable of automated driving through remote monitoring and remote 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. This embodiment is applicable not only to unmanned automated driving vehicles but also to manned automated driving vehicles.

[0011] 1 to 3, vehicle 1 equipped with a cruise control device according to this 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 components 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. Vehicle 1 further includes a communication device 25 for communicating remote operation commands, 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 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 external sensor 21 and the internal sensor 22 are configured to start operating at the same time as the start of the vehicle 1, and to constantly detect the surrounding environment and vehicle information.

[0017] 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.

[0018] The environmental state estimation unit 11 acquires the absolute position of the vehicle by matching the vehicle position information obtained by a positioning means 24, such as a Global Navigation Satellite System (GNSS), with the map information in the map information database 23. The environmental state estimation unit 11 estimates the positions of the lane markings of the vehicle 1'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. Note that instead of acquiring the absolute position of the vehicle 1 based on the vehicle position information obtained by the positioning means 24 and the map information in the map information database 23, the environmental state estimation unit 11 can also be configured to use Simultaneous Localization and Mapping (SLAM) to estimate the current position of the vehicle, or to determine the relative position of the vehicle 1 with respect to the lane markings of adjacent lanes obtained from the external sensor 21.

[0019] The environmental state estimation unit 11 is further configured to acquire information about road shapes, such as whether or not a roundabout exists on the road and whether or not there is an evacuation space around the roundabout where the vehicle can stop, based on map information from, for example, a map information database 23. Roundabouts will be described later. The environmental state estimation unit 11 also acquires the motion state of the vehicle 1 from internal data measured by the internal sensor 22.

[0020] 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 remote operation of the driving control device by the remote control base station 25R via the communication device 25, that is, when it becomes difficult to automatically drive the vehicle 1 through remote monitoring and remote operation.

[0021] 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 route of the vehicle 1 changes from the target route of the automated driving due to the activation of the RMF, the notification unit 17 may be configured to notify that the route (travel direction) of the vehicle 1 will change. The notification unit 17 may be configured to notify people inside and outside the vehicle that automated driving by remote monitoring and remote control 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.

[0022] 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.

[0023] 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.

[0024] 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. It is also possible to use, for example, an electric motor as a drive device for the vehicle 1 instead of or in addition to the engine 42.

[0025] [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 remotely controlled 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.

[0026] 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.

[0027] An operator of 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 of other vehicles traveling in the vehicle's lane and adjacent lanes, speed, presence or absence of pedestrians or bicycles, etc.) acquired by the external sensor 21 and internal information (vehicle speed, yaw rate, acceleration, etc.) acquired by the internal sensor 22.

[0028] 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.

[0029] The vehicle control unit 14 calculates the yaw rate γ and lateral acceleration (d 2 y / dt 2 ) the speed, attitude, and lateral displacement of the vehicle 1 after Δt seconds are estimated from the relationship. The vehicle control unit 14 provides a steering angle command to the EPS controller 31 via the automatic steering controller 16 so that the lateral displacement after Δt seconds will be yt, and provides a speed command to the ACC controller 15 so that the speed will be Vt after Δt seconds.

[0030] 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 operation device 10 while the automatic driving system is operating.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] 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.

[0037] [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.

[0038] Based on a signal from the environmental state estimation unit 11, the RMF unit 12 determines that it is necessary to activate the RMF when it becomes difficult to remotely monitor and remotely control the vehicle 1 by the remote control base station 25R due to a disconnection of communication with the remote control base station 25R, a malfunction of the communication device 25, etc., and activates the RMF to guide the vehicle 1 to a target stopping area and stop it. The target stopping area of the RMF is usually set as a space on the target route for autonomous driving where the vehicle 1 can be stopped.

[0039] Here, a roundabout, a type of intersection, may be installed on a road. A roundabout is a type of intersection where multiple roads are connected via a circular space, and is configured so that vehicles travel in one direction around a circular road around a central island in the center of the circular space (see Figure 4). At a roundabout, traffic on the circular road has priority. Vehicles entering a roundabout can enter the circular road at a slow speed without stopping if there are no vehicles traveling on the circular road.

[0040] If the RMF is activated near an intersection, there is a possibility that vehicle 1 may cross paths with other traffic participants at the intersection or disrupt traffic flow while being guided to the target stopping area while slowing down. In particular, because roundabouts differ in form from ordinary crossroads or T-junctions, if the RMF is activated near or within a roundabout, it is desirable to safely guide vehicle 1 to the target stopping area so as not to disrupt traffic flow at the roundabout or cause contact or collision with other traffic participants.

[0041] Therefore, in this embodiment, when RMF is activated near or within a roundabout, 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.

[0042] Here, the case where RMF is activated near a roundabout means, for example, a situation in which decelerating or stopping vehicle 1 by RMF activation causes vehicle 1 to stop in or near the roundabout, resulting in disruption of traffic flow at the roundabout and the risk of contact or collision with other traffic participants. Similar to normal intersections, a roundabout has a designated no-parking zone set within and around the roundabout. Therefore, for example, when vehicle 1 is at a stage (point or time) where it cannot stop before the no-parking zone of the roundabout even if it decelerates at a designated deceleration rate by RMF activation, it is determined that RMF will be activated near the roundabout.

[0043] That is, the RMF is activated to reduce the vehicle speed to a predetermined deceleration (for example, 4.0 m / s 2) can be defined as a predetermined area before the roundabout where vehicle 1 will stop in the no-parking zone of the nearest roundabout if it decelerates at a predetermined deceleration rate due to the operation of the RMF, if the roundabout does not have a no-parking zone. If the roundabout does not have a no-parking zone, vehicle 1 may be defined as a predetermined area before the roundabout where vehicle 1 will stop in the nearest roundabout if it decelerates at a predetermined deceleration rate due to the operation of the RMF. Furthermore, outside the roundabout (see FIG. 4), or if the roundabout has a no-parking zone, outside the no-parking zone, can be defined as outside the roundabout.

[0044] [Setting target stop position for RMF] The automatic driving device 10 is configured such that the environmental state estimation unit 11 acquires the vehicle's position by matching the vehicle's 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 stop position candidates during automatic driving based on the vehicle's position and surrounding map information in preparation for RMF activation. When RMF activates, a target stop position is selected from the multiple target stop position candidates, and the vehicle 1 is guided to and stopped at the selected target stop position. Below, we will explain how to set the target stop position for RMF when RMF is activated near or within a roundabout.

[0045] (1) Setting target stop position candidates The RMF unit 12 is configured to acquire information such as the shape of the roundabout, the number of roads connected to the roundabout, and parking spaces available around the roundabout, if a roundabout exists on the target route, based on road information obtained from the map information database 23, for example.

[0046] FIG. 4 shows an example of a roundabout RA where traffic rules dictate keeping to the left. The roundabout RA shown in FIG. 4 is configured so that four roads A1 to A4 are connected and vehicles travel clockwise on a circular road C around a central island B. Pedestrian crossings D1 and D3 are installed on roads A1 and A3, respectively. Note that when traffic rules dictate keeping to the right, vehicles travel counterclockwise on the circular road C of the roundabout RA. The following explanation will be given using an example of keeping to the left.

[0047] Vehicle 1 is located on road A1 just before entrance E1 of roundabout RA. In the example shown in Fig. 4, the target route for automated driving set by route generation unit 13 is set to, for example, a route that goes halfway around roundabout RA and enters road A3 from exit E3, as indicated by arrow P3.

[0048] When a roundabout RA exists on the target route for automated driving, the RMF unit 12 sets a target stop position candidate outside the roundabout RA. As the target stop position candidates for RMF, a plurality of target stop position candidates including areas on a route different from the global route (target route) set by the route generation unit 13 can be set. Specifically, a plurality of target stop position candidates are set on a plurality of roads extending from the exit of the roundabout RA.

[0049] The RMF unit 12 searches for available stopping spaces on the roads A2 to A4 connected beyond the exits E2 to E4 of the roundabout RA based on map information obtained from the map information database 23, for example, and sets target stopping position candidates. That is, the RMF unit 12 sets target stopping position candidates outside the exits E2 to E4 of the roundabout RA so that the target stopping position S is located outside the roundabout RA. Although not shown in Fig. 4, the roundabout RA can be completed and the vehicle can return to the road A1 where the vehicle 1 is located, so the target stopping position candidate can also be set on the road A1.

[0050] The target stopping position candidate can be set, for example, to the shoulder of the road on which the vehicle 1 is traveling, an alley adjacent to the road on which the vehicle 1 is traveling, or a parking space facing the road on which the vehicle 1 is traveling. When setting the target stopping position candidate to the shoulder of the road, it is desirable to ensure an area large enough to prevent the stopped vehicle 1 from protruding into the lane. When setting the target stopping position candidate to an alley or parking space, it is desirable to enable the vehicle 1 to move to the target stopping position without crossing into the oncoming lane.

[0051] In the example shown in Fig. 4, the RMF unit 12 sets two target stop position candidates T21, T22 on road A2 extending from exit E2 of roundabout RA. In addition, two target stop position candidates T31, T32 are set on road A3 extending from exit E3 of roundabout RA, and two target stop position candidates T41, T42 are set on road A4 extending from exit E4 of roundabout RA. The target stop position candidates T21, T22 set on road A2 and the target stop position candidates T41, T42 set on road A4 are located on a route different from the target route for automated driving. Hereinafter, the target stop position candidates T21, T22, T31, T32, T41, T42 may be collectively referred to as target stop position candidates T.

[0052] (2) Selecting the target stop position The RMF unit 12 is configured to set priorities for the plurality of target stop position candidates T set as described above, and to select the target stop position candidate T with the highest priority from the plurality of target stop position candidates T as the target stop position S. First, a method for setting the priorities will be described.

[0053] The priority of the target stop position candidate T is basically set so that when the RMF is activated near or within the roundabout RA, the target stop position candidate T that can reduce the risk of disruption of traffic flow at the roundabout RA and contact or collision with other traffic participants is more likely to be selected as the target stop position S. In other words, the priority of the target stop position candidate T is set so that the lower the risk with other traffic participants when guiding and stopping the vehicle 1 when the RMF is activated, the higher the priority.

[0054] Therefore, the RMF unit 12 sets priorities for each target stop position candidate T based on various conditions, such as the distance that the vehicle 1 will travel before reaching the target stop position S when the RMF is activated, whether there is a crosswalk installed beyond the exit of the roundabout RA, and the lateral acceleration that acts on the vehicle 1 when it exits the roundabout RA. Furthermore, the RMF unit 12 changes the method of setting priorities for selecting the target stop position S depending on the position of the vehicle 1 when the RMF is activated. Specifically, the method of setting priorities differs between when the RMF is activated near the roundabout RA and when the RMF is activated inside the roundabout RA.

[0055] A: When RMF operates near a roundabout RA If the current position of vehicle 1 is, for example, position 1A in Figure 4 and RMF is activated near a roundabout RA, i.e., if RMF is activated before entering the roundabout RA, the priority is determined taking into account the following three conditions. (a1) Travel distance from the exit of the roundabout RA to the target stop position candidate T (a2) Whether or not there is a crosswalk on the road leading from the exit of the roundabout RA (a3) Distance traveled on circular road C from the entrance to the exit of roundabout RA

[0056] Regarding condition (a1), the shorter the travel distance from the exit of the roundabout RA to the target stop position candidate T, the lower the risk of contact or collision with other traffic participants, such as other vehicles, and therefore the higher the priority is. Regarding condition (a2), the higher the priority is given to the target stop position candidate T set on a road where there is no crosswalk beyond the exit of the roundabout RA. If a crosswalk is set, there is a possibility that pedestrians, etc., may be crossing the crosswalk, and there is a possibility that vehicle 1 may come into contact with pedestrians, etc., when crossing the crosswalk. Therefore, the priority of the target stop position candidate T set on a road where there is no crosswalk is set higher than the priority of the target stop position candidate T set on a road where there is a crosswalk.

[0057] Regarding condition (a3), the shorter the travel distance on the circular road C from the entrance to the exit of the roundabout RA, the lower the risk of contact or collision with other traffic participants, such as other vehicles, and therefore the higher the priority of the target stopping position candidate T set on the road extending from the exit. Furthermore, among the above three conditions, condition (a1) is given the highest priority (highest priority for determining the priority), followed by condition (a2), and finally condition (a3) is considered (lowest priority for determining the priority) ((a1)>(a2)>(a3)).

[0058] B: When RMF operates within a roundabout RA If the current position of vehicle 1 is, for example, position 1B in Figure 4 and RMF is activated within a roundabout RA, i.e., if RMF is activated after entering the roundabout RA, the priority is determined taking into account the following three conditions. (b1) Travel distance from the exit of the roundabout RA to the target stop position candidate T (b2) Whether or not there is a crosswalk on the road leading from the exit of the roundabout RA (b3) The distance traveled on the circular road C to the exit where the vehicle can exit the roundabout RA within the specified lateral acceleration.

[0059] Regarding condition (b1), similar to condition (a1), the shorter the driving distance from the exit of the roundabout RA to the target stop position candidate T, the higher the priority. Regarding condition (b2), similar to condition (a2), the higher the priority is for a target stop position candidate T that is set on a road that does not have a pedestrian crossing beyond the exit of the roundabout RA.

[0060] Regarding condition (b3), when vehicle 1 exits a roundabout RA, among a plurality of exits that can be passed through within a predetermined range of lateral acceleration acting on vehicle 1, the shorter the travel distance on the circular road C from the vehicle's position within the roundabout RA to the exit, the higher the priority of the target stopping position candidate T set beyond that exit. Furthermore, among the above three conditions, condition (b1) is given the highest priority (highest priority for determining the priority), followed by condition (b2), and finally condition (b3) is considered (lowest priority for determining the priority) ((b1)>(b2)>(b3)).

[0061] Here, condition (b3) is adopted so that vehicle 1 can travel without sudden steering when guiding vehicle 1 to target stop position S. The predetermined lateral acceleration is, for example, a value similar to the lateral acceleration that is allowable to act on vehicle 1 when vehicle 1 is automatically traveling along the target route. When vehicle 1 is automatically traveling along the target route, route generation unit 13 of automatic traveling device 10 calculates the target vehicle speed of vehicle 1 so that it does not exceed the allowable lateral acceleration, in order to reduce the mental or physical stress on the occupants, even when vehicle 1 turns right or left, for example. Therefore, even when vehicle 1 is guided to target stop position S after exiting roundabout RA during RMF operation, it is preferable to control the behavior of vehicle 1 so that it does not exceed a predetermined lateral acceleration (e.g., approximately 0.1 G) that is similar to the allowable lateral acceleration used in normal automatic traveling.

[0062] Therefore, while guiding the vehicle 1 from its current position in the roundabout RA to the target stop position S, the RMF unit 12 determines whether the vehicle 1 can turn at the exit of the roundabout RA within a predetermined lateral acceleration, i.e., whether the vehicle 1 can be guided with safe steering control. For example, in the example shown in FIG. 4 , if the current position of the vehicle 1 is position 1B in the roundabout RA, sudden steering is required to exit from the nearest exit E2 of the roundabout RA as indicated by arrow P2. In this case, since lateral acceleration exceeding the predetermined lateral acceleration occurs, it is determined that the vehicle 1 at position 1B cannot turn at the exit E2 within the predetermined lateral acceleration. On the other hand, when exiting from exits E3 and E4, since there is a sufficient distance from the vehicle 1 at position 1B, sudden steering is not required, and it is determined that the vehicle 1 can turn at the exits E3 and E4 within the predetermined lateral acceleration. If there are multiple exits at which the vehicle 1 can turn within the predetermined lateral acceleration, the shorter the distance from the current position of the vehicle 1 in the roundabout RA to the exit, the higher the priority of the target stop position candidate T set beyond the exit.

[0063] The RMF unit 12 may also take into account the longitudinal deceleration of the vehicle 1 when determining whether the vehicle 1 can turn at the exit of the roundabout RA within a predetermined lateral acceleration. For example, in the example shown in FIG. 4 , if the RMF is activated when the vehicle 1 is at position 1B within the roundabout RA, the vehicle 1 must suddenly decelerate in order to exit the nearest exit E2 of the roundabout RA within a predetermined lateral acceleration. This may impose mental or physical stress on the occupants of the vehicle 1. Therefore, when exiting the roundabout RA to guide the vehicle 1 to a target stop position, the RMF unit 12 may further determine whether the vehicle 1 can turn at the exit of the roundabout RA within a predetermined longitudinal deceleration (e.g., approximately 0.2 G). In this way, the RMF unit 12 may set a priority order for the target stop position candidates T by taking into account, for example, the vehicle speed, longitudinal deceleration, lateral speed, and lateral acceleration of the vehicle 1. This allows the vehicle 1 to be safely guided without sudden deceleration or sudden steering, thereby reducing stress on the occupants.

[0064] A specific example of priorities set for multiple target stop position candidates T will be described with reference to Fig. 5. Fig. 5 shows the conditions (a1), (a2), and (a3) and priorities associated with multiple target stop position candidates T21, T22, T31, T32, T41, and T42 in "A: When RMF operates near roundabout RA." Note that the current position of vehicle 1 is position 1A just before entrance E1 of roundabout RA.

[0065] For target stop position candidate T21 set on road A2 connected to exit E2, (a1) the driving distance from exit E2 is 100 m, (a2) there is no pedestrian crossing on road A2 extending from exit E2, and (a3) the driving distance from entrance E1 to exit E2 is 50 m. For target stop position candidate T22 set on road A2 connected to exit E2, (a1) the driving distance from exit E2 is 300 m, (a2) there is no pedestrian crossing on road A2 extending from exit E2, and (a3) the driving distance from entrance E1 to exit E2 is 50 m.

[0066] Regarding target stop position candidate T31 set on road A3 connected to exit E3, (a1) the driving distance from exit E3 is 50 m, (a2) a crosswalk D3 is installed on road A3 extending from exit E3, and (a3) the driving distance from entrance E1 to exit E3 is 100 m. Regarding target stop position candidate T32 set on road A3 connected to exit E3, (a1) the driving distance from exit E3 is 100 m, (a2) a crosswalk D3 is installed on road A3 extending from exit E3, and (a3) the driving distance from entrance E1 to exit E3 is 100 m.

[0067] For target stop position candidate T41 set on road A4 connected to exit E4, (a1) the driving distance from exit E4 is 50 m, (a2) there is no pedestrian crossing on road A4 extending from exit E4, and (a3) the driving distance from entrance E1 to exit E4 is 200 m. For target stop position candidate T42 set on road A4 connected to exit E4, (a1) the driving distance from exit E4 is 300 m, (a2) there is no pedestrian crossing on road A4 extending from exit E4, and (a3) the driving distance from entrance E1 to exit E4 is 200 m.

[0068] Condition (a1) has the highest priority for determining the priority order. Therefore, first, considering condition (a1), the travel distance from exit E3 to target stop position candidate T31 set on road A3 and the travel distance from exit E4 to target stop position candidate T41 set on road A4 are 50 meters, which is the shortest. Therefore, these target stop position candidates T31, T41 have a higher priority than the other target stop position candidates. Next, considering condition (a2) for these target stop position candidates T31, T41, a crosswalk D3 is installed on road A3, where target stop position candidate T31 is set, while a crosswalk is not installed on road A4, where target stop position candidate T41 is set. Therefore, the priority order of target stop position candidate T41 is higher than that of target stop position candidate T31. As a result, the priority order of target stop position candidate T41 is set to be first, and the priority order of target stop position candidate T31 is set to be second.

[0069] Regarding the remaining target stop position candidates, when condition (a1) is considered, the travel distance from exit E2 to target stop position candidate T21 set on road A2 and the travel distance from exit E3 to target stop position candidate T32 set on road A3 are both 100 m, which is shorter, and therefore the target stop position candidate T21 has a higher priority. Next, when condition (a2) is considered for these target stop position candidates T21 and T32, there is no pedestrian crossing on road A3 on which target stop position candidate T21 is set, but there is pedestrian crossing D3 on road A3 on which target stop position candidate T32 is set. Therefore, the target stop position candidate T21 has a higher priority than the target stop position candidate T32. As a result, the priority of target stop position candidate T21 is set to third, and the priority of target stop position candidate T32 is set to fourth.

[0070] Regarding the remaining target stop position candidates, when condition (a1) is considered, the travel distance from exit E2 to target stop position candidate T22 set on road A2 and the travel distance from exit E4 to target stop position candidate T42 set on road A4 are both 300 m. Next, when condition (a2) is considered for these target stop position candidates T22 and T42, no crosswalks are installed on either road A3 on which target stop position candidate T22 is set or road A4 on which target stop position candidate T42 is set. Therefore, when condition (a3) is further considered, the travel distance (50 m) from entrance E1 to exit E2 of the roundabout RA for heading towards target stop position candidate T22 (distance on circular road C) is shorter than the travel distance (200 m) from entrance E1 to exit E4 of the roundabout RA for heading towards target stop position candidate T42. Therefore, the priority of target stop position candidate T22 is set to 5th, and the priority of target stop position candidate T42 is set to 6th.

[0071] As described above, the RMF unit 12 sets a priority order for each of the multiple target stop position candidates T, and selects the target stop position candidate T with the highest priority order from the multiple target stop position candidates T as the target stop position S. In the example shown in FIG. 5 , of the multiple target stop position candidates T21, T22, T31, T32, T41, and T42, the target stop position candidate T41 that is located outside the roundabout RA and has the highest priority order is selected as the target stop position S. As described above, the target route for automated driving is a route that enters road A3 from exit E3 as indicated by arrow P3, and therefore the target stop position S corresponding to target stop position candidate T41 set on road A4 will be located on the route indicated by arrow P4, which is different from the target route for automated driving.

[0072] [RMF operation flow during autonomous driving] Next, the flow of RMF operation when a situation arises during autonomous driving that makes remote monitoring and remote operation difficult will be described. Fig. 6 shows a flowchart illustrating the flow of RMF operation according to this embodiment. Note that the RMF unit 12 is configured to always set a plurality of target stop position candidates T in preparation for RMF operation, regardless of whether or not there is a roundabout RA on the target route. Here, a case will be described in which a roundabout RA exists ahead of the vehicle 1 on the target route, and the RMF is activated near or within the roundabout RA.

[0073] (1) Automatic driving operation by remote monitoring and remote control (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.

[0074] (2) Setting multiple target stop position candidates (step S102) The RMF unit 12 searches for target stop position candidates T 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 T along the global route to the destination in preparation for RMF operation. During automated driving, the RMF unit 12 sets multiple target stop position candidates T outside a roundabout RA that exists on the target route, i.e., on roads connected to the exit of the roundabout RA. The multiple target stop position candidates T are constantly updated, and the latest target stop position candidate T based on the current position of the vehicle 1 is set.

[0075] (3) Communication failure determination (step S104) While the automatic operation device 10 is operating through remote monitoring and remote control, 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 remote control of automatic driving by the automatic operation device 10, the process proceeds to step S106 to activate the RMF. On the other hand, if no communication failure has occurred and automatic driving through remote monitoring and remote control can be continued, the process returns to step S102 and automatic driving continues.

[0076] (4) Stopping remote monitoring and remote operation (steps S106 to S110) If it is determined that it has become difficult to continue automatic driving through remote monitoring and remote control, a flag indicating a communication failure is set (step S106), and at the same time, the alarm unit 17 notifies those inside and outside the vehicle that the operation (automatic driving) of the automatic driving device 10 through remote monitoring and remote control will be stopped (step S108), and the operation of the automatic driving device 10 through remote monitoring and remote control will be stopped (step S110).

[0077] (5) RMF operation notification (step S112) When the RMF is activated due to a situation where it is difficult to continue remote monitoring and remote 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.

[0078] (6) Selecting a target stop position (step S114) A target stop position S is selected from a plurality of target stop position candidates T. The RMF unit 12 sets priorities for each of the plurality of target stop position candidates T set in step S102 as described above, and selects the target stop position candidate T with the highest priority as the target stop position S. As a result, when the RMF is to be activated near or within the roundabout RA, a target stop position S located outside the roundabout RA is selected. The route generation unit 13 generates a target route for RMF activation to the selected target stop position S based on the host vehicle position information, map information, information about the shape of the roundabout RA, positions and speeds of other vehicles, the motion state of the host vehicle, etc. acquired by the environmental state estimation unit 11.

[0079] (7) RMF operation (step S116) 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.

[0080] (8) Determining whether or not the vehicle can stop at the target stop position S (step S118) 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 S120.

[0081] On the other hand, for example, if there is another vehicle at target stopping position S or construction work is being carried out near target stopping position S, it is determined that vehicle 1 cannot stop at target stopping position S due to obstacles around target stopping position S. In this case, the process returns to step S114 and a new target stopping position S is selected. For example, by setting a plurality of target stopping position candidates T for each of roads A2, A3, and A4 as shown in FIG. 4, in a situation where vehicle 1 cannot stop at the selected target stopping position S after exiting roundabout RA, a target stopping position candidate T that is set farther away than the selected target stopping position S can be quickly determined as an alternative target stopping position S.

[0082] (9) Deceleration and Stopping by RMF (Steps S120 to S124) The automatic operation device 10 activates a direction indicator (not shown) in the direction of the target stop position S (step S120). 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 S122). The automatic operation device 10 flashes hazard lights (not shown) (step S124).

[0083] (10) RMF completion determination (steps S126 to S128) The RMF unit 12 matches the position where the vehicle 1 has stopped with the target stopping 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 S122 and the vehicle travels to the target stopping position S. If the stopping position of the vehicle 1 matches the target stopping position S, the process determines that the RMF has been completed, and proceeds to step S128, where the RMF is stopped. This ends the series of RMF processes.

[0084] The driving control device for the vehicle 1 according to the present embodiment described above can achieve the following advantageous effects.

[0085] A driving control device of a vehicle 1 equipped with an automatic operation device 10 for performing automatic driving by remote monitoring and remote operation has a risk mitigation function (RMF) that performs risk mitigation control to stop the vehicle 1 at a target stopping position when a situation arises in which it is difficult to continue automatic driving by remote monitoring and remote operation. The automatic operation device 10 is configured to search for a target stopping position candidate T based on position information and map information of the vehicle 1 during automatic driving in preparation for activation of the RMF, set multiple target stopping position candidates T including a target stopping position candidate T located on a route different from the target route of automatic driving, set the target stopping position candidate T outside the roundabout RA if a roundabout RA is present on the target route, and select a target stopping position S from the multiple target stopping position candidates T when the RMF is activated near or within the roundabout RA.

[0086] Even if a roundabout RA is present on the target route for automated driving, the target stop position candidate T is not set within the roundabout RA. Therefore, when the RMF is activated near or within the roundabout RA, a target stop position S located outside the roundabout RA can be selected, and the vehicle 1 can be guided to a safe area and stopped. Multiple target stop position candidates T can also be set on routes different from the target route for automated driving. This prevents the vehicle 1 from stopping in a location that obstructs the passage of other traffic participants, regardless of the target route for automated driving, and also prevents the vehicle 1 from traveling in a location that poses a risk of inducing contact or collision with other traffic participants. Furthermore, since multiple target stop position candidates T are searched for during automated driving, if a situation arises in which it becomes difficult to continue automated driving by remote monitoring and remote control, such as in the case of a communication failure with the remote control base station 25R for remote monitoring and remote control, the target stop position S can be quickly selected when the RMF starts operating.

[0087] Multiple target stop position candidates T are set on multiple roads extending from the exit of the roundabout RA. This makes it possible to select a target stop position S from the multiple target stop position candidates T that can reduce the risk of disrupting traffic flow and contact with or inducing contact with other traffic participants, regardless of the target route of the automated driving.

[0088] The RMF unit 12 sets a plurality of target stop position candidates T on each of a plurality of roads extending from the exit of the roundabout RA. Two or more target stop position candidates T are set beyond one exit of the roundabout RA. As a result, for example, if an obstacle exists at the selected target stop position S and the vehicle 1 cannot stop, it is possible to select a target stop position candidate T on the same road as the target stop position S, and therefore the target stop position S can be quickly switched to stop the vehicle 1 safely.

[0089] The RMF unit 12 is configured to set a priority for each of the multiple target stop position candidates T, and select the target stop position candidate T with the highest priority from the multiple target stop position candidates T as the target stop position S. The shorter the distance from the exit of the roundabout RA to the target stop position candidate T, the higher the priority. By setting a higher priority when selecting the target stop position S as the distance from the exit of the roundabout RA to the target stop position candidate T is shorter, the distance traveled by the vehicle 1 with the RMF activated can be shortened, and the risk of contact with other traffic participants, etc. can be reduced.

[0090] The RMF unit 12 prioritizes the target stop position candidate T set on a road where a pedestrian crossing is not installed beyond the exit of the roundabout RA higher than the priority of the target stop position candidate T set on a road where a pedestrian crossing is installed beyond the exit of the roundabout RA. When a pedestrian crossing is installed, there is a possibility that pedestrians may be crossing the crosswalk, creating a risk of contact or collision with the pedestrians. Furthermore, when pedestrians are crossing the crosswalk, the vehicle 1 needs to wait until the pedestrians cross the crosswalk, which increases the time required to reach the target stop position S. Therefore, by increasing the priority of the target stop position candidate set on a road where a pedestrian crossing is not installed, the vehicle 1 is more likely to be selected as the target stop position S, thereby avoiding the risk of contact or collision with the pedestrians crossing the crosswalk and eliminating the time required to wait for the pedestrians crossing the crosswalk, and safely guiding the vehicle 1 to the target stop position S in a short time.

[0091] When the RMF is activated near a roundabout RA, the shorter the distance from the entrance E1 of the roundabout RA closest to the vehicle 1 to the exit of the roundabout RA, the higher the priority of the target stop position candidate T set on the road extending from that exit. This makes it possible to shorten the distance traveled by the vehicle 1 while the RMF is activated, and reduce the risk of contact or collision with other traffic participants.

[0092] When the RMF is activated within a roundabout RA, the RMF unit 12 assigns a higher priority to a target stop position candidate T set ahead of an exit among multiple exits from which the vehicle 1 can exit the roundabout RA within a predetermined lateral acceleration, the shorter the distance from the vehicle 1 to the exit. By selecting an exit that does not require sudden steering to move to a target stop position S set outside the roundabout RA, the burden on the occupants of the vehicle 1 can be reduced. Furthermore, if there are multiple exits that do not require sudden steering, the target stop position candidate T set ahead of the exit closest to the vehicle 1 is selected as the target stop position S, thereby shortening the distance traveled by the vehicle 1 with the RMF activated.

[0093] -Variations- (1) In the above-described embodiment, in preparation for the activation of the RMF, multiple target stop position candidates T were set for each of the multiple roads A2 to A4 beyond each of the exits E2 to E4 of the roundabout RA. However, this is not limited to this, and multiple target stop position candidates T may not be set for each of the multiple roads. For example, only one target stop position candidate T may be set for any of the multiple roads in the roundabout RA, or no target stop position candidate T may be set for any of the roads. Also, in the example shown in FIG. 4, two target stop position candidates T were set for each of the roads A2 to A4, but the number of target stop position candidates T set for each road is not limited to two and may be three or four. In other words, the RMF unit 12 may be configured to set one or more target stop position candidates T for at least one of the multiple roads extending from the exit of the roundabout RA, and to set multiple target stop position candidates T in relation to the roundabout RA.

[0094] (2) In order to select a target stop position S from among the target stop position candidates T, the RMF unit 12 may consider whether the target stop position candidate T is set on the target route for autonomous driving. For example, a target stop position candidate set on the target route can be given a higher priority than a target stop position candidate set on a route different from the target route. This makes it possible to reduce the sense of anxiety felt by the occupants of the vehicle 1 when the RMF is activated and the vehicle 1 is guided to a route different from the target route for autonomous driving. The condition of whether the target stop position candidate T is set on the target route for autonomous driving may be used in addition to, for example, the above-described conditions (a1) to (a3) and conditions (b1) to (b3), or may be used instead of, for example, the above-described condition (a3) or condition (b3).

[0095] (3) When RMF is activated near or within a roundabout RA, the route generation unit 13 may generate a target route for RMF activation so that the vehicle 1 travels along the side edge (outer edge) of the circular road C of the roundabout RA. For example, when the circular road C of the roundabout RA has multiple lanes, the target route for automated driving may be set so that the vehicle 1 travels along the lane closest to the center island B among the multiple lanes of the circular road C. In such a case, when it is determined that RMF will be activated near or within the roundabout RA, the route generation unit 13 changes the target route so that the vehicle 1 travels along the side edge of the circular road C of the roundabout RA.

[0096] If the vehicle 1 travels in the lane closest to the center island B (the innermost lane) of the circular road C, the driving distance to the exit of the roundabout RA will be shorter, but depending on the driving conditions of other vehicles traveling in adjacent lanes, for example, it may not be possible to move to the desired exit. Therefore, by changing the target route for automatic driving so that the vehicle travels in the lane closest to the side edge of the circular road C as the target route for RMF operation, the vehicle 1 can be guided more safely to the target stopping position S.

[0097] 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]

[0098] 1 vehicle 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 31 EPS controller 32 Engine Controller 33 ESP / ABS controller 34 Manual steering (steering wheel) 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 remote 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 autonomous driving through remote monitoring and remote operation, The automatic operation device is During the automatic driving, in preparation for the activation of the RMF, a search for a target stopping position candidate is performed based on position information and map information of the vehicle; setting a plurality of target stop position candidates including target stop position candidates located on a route different from the target route of the automatic driving, and if a roundabout is present on the target route, setting the target stop position candidate outside the roundabout; A vehicle cruise control device configured to select a target stopping position from the plurality of target stopping position candidates when the RMF is activated near or within a roundabout.

2. The vehicle cruise control device according to claim 1 , wherein the plurality of target stop position candidates are set on a plurality of roads extending from an exit of the roundabout.

3. The vehicle cruise control device according to claim 2 , wherein a plurality of target stop position candidates are set for each of the plurality of roads extending from an exit of the roundabout.

4. a priority order is set for each of the plurality of target stop position candidates, and the target stop position candidate with the highest priority order is selected as the target stop position from among the plurality of target stop position candidates, The vehicle cruise control device according to claim 2 , wherein the priority is higher as the distance from the exit of the roundabout to the target stop position candidate is shorter.

5. 5. The vehicle driving control device according to claim 4, wherein a priority of a target stop position candidate set on a road where a pedestrian crossing is not installed beyond the exit of the roundabout is higher than a priority of a target stop position candidate set on a road where a pedestrian crossing is installed beyond the exit of the roundabout.

6. 6. A vehicle driving control device according to claim 5, wherein when the RMF is activated near the roundabout, the shorter the distance from the entrance of the roundabout closest to the vehicle to the exit of the roundabout, the higher the priority of the target stopping position candidate set on the road extending from the exit.

7. 6. A vehicle driving control device according to claim 5, wherein, when the RMF is activated within the roundabout, the priority of a target stop position candidate set beyond an exit is increased the shorter the distance from the vehicle to the exit, among a plurality of exits from which the vehicle can exit the roundabout within a predetermined lateral acceleration.

8. The vehicle cruise control device according to claim 5 , wherein a priority of a target stop position candidate located on the target route is higher than a priority of a target stop position candidate located on a route different from the target route.

9. 9. The vehicle driving control device according to claim 1, wherein, when the RMF is activated near a roundabout or within the roundabout, the target route is changed so that the vehicle travels along a side edge of a circular road of the roundabout.

Images