JP7508270B2 - Vehicle driving support method and driving support device - Google Patents

Description

The present invention relates to a vehicle driving assistance method and driving assistance device.

A technology is known that dynamically changes the target time interval with the vehicle ahead based on the time interval with the following vehicle when changing lanes, thereby controlling the time interval with both the vehicle ahead and the following vehicle so that it does not fall below the limit time interval, thereby enabling smooth driving that takes into consideration both the vehicle ahead and the following vehicle (Patent Document 1).

JP 2019-38322 A

However, with the above-mentioned conventional technology, there is a risk that the vehicle may stop straddling the lane, especially when the vehicle ahead stops while the vehicle is changing lanes, causing a traffic disruption for other vehicles, such as the following vehicle.

The problem that this invention aims to solve is to provide a driving assistance method and device that does not interfere with the traffic of other vehicles.

The present invention solves the above problem by setting a target inter-vehicle distance between the vehicle and the preceding vehicle to a first target inter-vehicle distance when a detected preceding vehicle stops and the vehicle stops behind the preceding vehicle, determining whether or not it is necessary to set a second target inter-vehicle distance smaller than the set first target inter-vehicle distance as the target inter-vehicle distance based on the situation of the vehicle when the vehicle stops behind the preceding vehicle at the first target inter-vehicle distance or the situation of other vehicles or pedestrians, and if it is determined that it is necessary to set the second target inter-vehicle distance, setting the target inter-vehicle distance to the second target inter-vehicle distance, controlling the driving of the vehicle so that the inter-vehicle distance between the vehicle and the preceding vehicle becomes the second target inter-vehicle distance , adjusting the inter-vehicle distance, and if it is determined that the vehicle cannot complete a lane change from the vehicle's own lane to an adjacent lane, setting the target inter-vehicle distance to the second target inter-vehicle distance .

The present invention makes it possible to prevent one's own vehicle from interfering with the traffic of other vehicles.

1 is a block diagram showing a driving assistance system including a vehicle driving assistance method and a driving assistance device according to the present invention; 4 is a flowchart showing an information processing procedure in the driving assistance system of FIG. 1 . FIG. 3A is a plan view (part 1) showing an example of a driving scene in which autonomous control of driving operation is performed by the driving assistance system shown in FIG. 1 . FIG. 3B is a plan view (part 2) showing an example of a driving scene in which autonomous control of driving operation is performed by the driving assistance system shown in FIG. 1 . FIG. 4A is a plan view showing an example of an unsuitable stopping area according to the present embodiment. FIG. 4B is a plan view showing another example of an unsuitable stopping area according to the present embodiment. FIG. 4C is a plan view showing yet another example of the unsuitable stopping area according to the present embodiment. FIG. 4D is a plan view showing yet another example of the unsuitable stopping area according to the present embodiment. FIG. 4E is a plan view showing yet another example of an unsuitable stopping area according to the present embodiment. FIG. 5A is a plan view (part 1) showing another example of a driving scene in which autonomous control of driving operation is performed by the driving assistance system shown in FIG. 1 . FIG. 5B is a plan view (part 2) showing another example of a driving scene in which autonomous control of driving operation is performed by the driving assistance system shown in FIG. 1 . FIG. 6A is a plan view (part 1) showing yet another example of a driving scene in which autonomous control of driving operation is performed by the driving assistance system shown in FIG. 1 . FIG. 6B is a plan view (part 2) showing yet another example of a driving scene in which autonomous control of driving operation is performed by the driving assistance system shown in FIG. 1 . FIG. 6C is a plan view (part 3) showing yet another example of a driving scene in which autonomous control of driving operation is performed by the driving assistance system shown in FIG. 1 . FIG. 7A is a flowchart showing an example of a subroutine of step S7 shown in FIG. FIG. 7B is a flowchart showing an example of a subroutine of step S8 shown in FIG. FIG. 8 is a flow chart showing another example of the subroutine of step S7 shown in FIG. FIG. 9 is a flow chart showing yet another example of the subroutine of step S7 shown in FIG. FIG. 10A is a plan view (part 1) showing an example of a driving scene in which autonomous control of driving operation is performed by a driving assistance system according to a comparative example of the present invention. FIG. 10B is a plan view (part 2) showing an example of a driving scene in which autonomous control of driving operation is performed by a driving assistance system according to a comparative example of the present invention.

The following describes an embodiment of the present invention with reference to the drawings.

The vehicle driving support method and vehicle driving support device according to the present invention can be applied to autonomous driving control that autonomously executes vehicle speed control and vehicle steering control, and can also be applied to a navigation system that presents an appropriate driving route when the driver is driving manually to support the driver's manual driving. When applied to autonomous vehicle driving control, it can be applied to cases where both speed control and steering control are autonomously controlled, or where one of speed control and steering control is autonomously controlled and the other is manually controlled. An example of applying the vehicle driving support method and vehicle driving support device according to the present invention to a vehicle equipped with an autonomous driving control function is described below.

Figure 1 is a block diagram showing the configuration of a driving assistance system 1000. The driving assistance system 1000 of this embodiment includes a driving assistance device 100 and a vehicle control device 200. The driving assistance device 100 of this embodiment includes a communication device 111, and the vehicle control device 200 also includes a communication device 211. The driving assistance device 100 and the vehicle control device 200 exchange information with each other via wired communication or wireless communication.

More specifically, the driving assistance system 1000 of this embodiment includes a detection device 1, a navigation device 2, map information 3 stored in a readable recording medium, a vehicle information detection device 4, an environment recognition device 5, an object recognition device 6, a driving assistance device 100, and a vehicle control device 200. As shown in FIG. 1, the detection device 1, the navigation device 2, the map information 3 stored in a readable recording medium, the vehicle information detection device 4, the environment recognition device 5, the object recognition device 6, and the driving assistance device 100 are connected to each other by a CAN (Controller Area Network) or other in-vehicle LAN to exchange information with each other.

The detection device 1 of this embodiment detects information about the driving environment including the presence of obstacles located around the host vehicle, such as the entire periphery in front of, to the sides of, and behind the host vehicle, and other conditions around the host vehicle. The detection device 1 of this embodiment includes an imaging device for recognizing environmental information around the host vehicle, such as a camera equipped with an imaging element such as a CCD, an ultrasonic camera, or an infrared camera. The imaging device of this embodiment is installed on the host vehicle, captures images of the surroundings of the host vehicle, and obtains image data including target vehicles that are present around the host vehicle.

The detection device 1 of this embodiment includes a distance measuring device, which calculates the relative distance and relative speed between the vehicle and an object. Information on the object detected by the distance measuring device is output to the processor 10. The distance measuring device may be a type known at the time of filing, such as a laser radar, a millimeter wave radar (LRF, etc.), a LiDAR (light detection and ranging) unit, or an ultrasonic radar.

The detection device 1 of this embodiment can employ one or more imaging devices and a distance measuring device. The detection device 1 of this embodiment has a sensor fusion function that integrates or synthesizes information from multiple different devices, such as detection information from the imaging device and detection information from the distance measuring device, to supplement information that is missing in the detection information and generate environmental information around the vehicle. This sensor fusion function may be incorporated into the environment recognition device 5, object recognition device 6, or other controllers or logic.

The objects detected by the detection device 1 include lane boundaries, center lines, road markings, medians, guardrails, curbs, side walls of expressways, road signs, traffic lights, crosswalks, construction sites, accident sites, and traffic restrictions. The objects detected by the detection device 1 include automobiles (other vehicles) other than the host vehicle, motorcycles, bicycles, and pedestrians. The objects detected by the detection device 1 include obstacles. Obstacles are objects that may affect the running of the host vehicle. The detection device 1 detects at least information about obstacles. The position information of the object detected by the detection device 1 can be detected based on self-position information, such as GPS, which is the position where the host vehicle is running, and the relative position (distance and direction) between the host vehicle and the object. The object detected by the detection device 1 can also be detected by correlating the position information of the object with map information based on map information, self-position information, which is the position where the host vehicle is running using odometry, and the relative position (distance and direction) between the host vehicle and the object.

The navigation device 2 of this embodiment refers to map information 3 and calculates the driving lane/driving route from the current position detected by the vehicle information detection device 4 to the destination. The driving lane or driving route is a linear diagram that identifies the road, direction (uphill/downhill) and lane on which the vehicle is traveling. The driving route includes information about the driving lane. Hereinafter, the driving lane may be abbreviated to lane.

The map information 3 of this embodiment is stored in a readable state in a recording medium provided in the driving support device 100, the in-vehicle device, or the server device, and is used for route generation and/or driving control. The map information 3 of this embodiment includes road information, facility information, and their attribute information. The road information and road attribute information include information such as road width, curvature radius, road shoulder structures, road traffic regulations (speed limit, lane change permission or not), road merging points, branching points, and positions where the number of lanes increases or decreases. The map information 3 of this embodiment is so-called high-definition map information, and the high-definition map information makes it possible to grasp the movement trajectory for each lane. The high-definition map information includes two-dimensional position information and/or three-dimensional position information at each map coordinate, road/lane boundary information at each map coordinate, road attribute information, lane uphill/downhill information, lane identification information, and destination lane information.

The map information 3 of this embodiment also includes information on lane boundaries that indicate the boundaries between the lane on which the vehicle is traveling and other lane boundaries. The lane on which the vehicle is traveling is the road on which the vehicle is traveling, and the form of the lane is not particularly limited. Lane boundaries exist on both the left and right sides of the traveling direction of the vehicle. The form of the lane boundary is not particularly limited, and examples include road markings and road structures. Examples of lane boundaries on road markings include lane boundaries and center lines. Examples of lane boundaries on road structures include median strips, guard rails, curbs, tunnels, or side walls of expressways. Note that lane boundaries are preset in the map information 3 for points where lane boundaries cannot be clearly identified (for example, within intersections). The preset lane boundaries are imaginary lane boundaries and are not actually existing road markings or road structures.

The host vehicle information detection device 4 of this embodiment acquires detection information related to the state of the host vehicle. The state of the host vehicle includes the current position, speed, acceleration, attitude, and vehicle performance of the host vehicle. These may be acquired from the vehicle control device 200 of the host vehicle, or from each device of the host vehicle. The host vehicle information detection device 4 of this embodiment acquires the current position of the host vehicle based on information acquired from the GPS (Global Positioning System) unit, gyro sensor, and odometry of the host vehicle. The host vehicle information detection device 4 of this embodiment also acquires the speed and acceleration of the host vehicle from the vehicle speed sensor of the host vehicle. The host vehicle information detection device 4 of this embodiment also acquires attitude data of the host vehicle from the inertial measurement unit (IMU) of the host vehicle.

The environment recognition device 5 of this embodiment recognizes object recognition information obtained from the position information acquired by the detection device 1, image information and distance measurement information around the host vehicle, and information about the environment constructed based on map information. The environment recognition device 5 of this embodiment generates environmental information around the host vehicle by integrating multiple pieces of information. The object recognition device 6 of this embodiment also uses the map information 3 and the image information and distance measurement information around the host vehicle acquired by the detection device 1 to predict the recognition and movement of objects around the host vehicle.

The vehicle control device 200 of this embodiment is an on-board computer such as an electronic control unit (ECU), and electronically controls the drive mechanism 210 that governs the driving of the vehicle. The vehicle control device 200 controls the drive device, braking device, and steering device included in the drive mechanism 210 to drive the host vehicle according to the target vehicle speed and target driving route. A control command based on the driving plan of the host vehicle is input to the vehicle control device 200 from the driving assistance device 100. The target vehicle speed, target driving route, and driving plan of the host vehicle will be described later.

The drive mechanism 210 in this embodiment includes an electric motor and/or an internal combustion engine as a driving source, a power transmission device including a drive shaft and an automatic transmission that transmits the output from these driving sources to the drive wheels, a drive device that controls the power transmission device, a braking device that brakes the wheels, and a steering device that controls the total steering wheel according to the steering angle of the steering wheel (so-called handle). A control signal corresponding to the target vehicle speed is input from the driving support device 100 to the vehicle control device 200. The vehicle control device 200 generates each control signal for these drive mechanisms 210 based on the control signal input from the driving support device 100, and executes driving control including acceleration and deceleration of the vehicle. By transmitting control information to the drive device of the drive mechanism 210, the vehicle speed control can be controlled autonomously.

The vehicle control device 200 of this embodiment also uses one or more of the lane information stored in the map information 3, the information recognized by the environment recognition device 5, and the information acquired by the object recognition device 6 to control the steering device of the drive mechanism 210 so that the vehicle travels while maintaining a predetermined lateral position (position in the left-right direction of the vehicle) with respect to the target travel route. The steering device has a steering actuator, and the steering actuator includes a motor attached to the steering column shaft. A control signal corresponding to the target travel route is input from the driving support device 100 to the vehicle control device 200. The steering device of the drive mechanism 210 performs steering control of the vehicle based on the control signal input from the vehicle control device 200. By transmitting control information to the steering device of the drive mechanism 210, the vehicle steering control can be controlled autonomously.

The driving support device 100 of this embodiment controls the driving of the vehicle to execute control to assist the driving of the vehicle. As shown in FIG. 1, the driving support device 100 of this embodiment includes a processor 10. The processor 10, which is a control device, is a computer that includes a ROM 12, which is a read only memory (ROM) that stores a program for executing driving control of the vehicle, a CPU 11, which is a central processing unit (CPU) that functions as the driving support device 100 by executing the program stored in the ROM 12, and a RAM 13, which is a random access memory (RAM) that functions as an accessible storage device. The processor 10 of this embodiment controls various functions through the cooperation of software for realizing the above functions and the above hardware. The processor 10 includes a communication device 111 and an output device 110, and outputs various output or input commands, information reading permission or information provision commands to the vehicle control device 200, the navigation device 2, the map information 3, the vehicle information detection device 4, the environment recognition device 5, and the object recognition device 6. The processor 10 exchanges information with the detection device 1, the navigation device 2, the map information 3, the vehicle information detection device 4, the environment recognition device 5, the object recognition device 6, and the vehicle control device 200.

The processor 10 of this embodiment includes a destination setting unit 120, a route planning unit 130, a driving plan unit 140, a driveable area calculation unit 150, a route calculation unit 160, and a driving behavior control unit 170, each of which performs its own function. The processor 10 of this embodiment is configured by software for realizing or executing the processing of each of the destination setting unit 120, the route planning unit 130, the driving plan unit 140, the driveable area calculation unit 150, the route calculation unit 160, and the driving behavior control unit 170, in cooperation with the hardware described above.

The control procedure by the processor 10 of this embodiment will be described with reference to FIG. 2. FIG. 2 is a flowchart showing the information processing procedure of the driving assistance system according to this embodiment. An overview of the autonomous driving control process executed by the driving assistance device 100 will be described with reference to FIG. 2.

2, the processor 10 executes a process of acquiring the current position of the vehicle based on the detection result of the vehicle information detection device 4 by the destination setting unit 120, and executes a process of setting the destination of the vehicle by the destination setting unit 120 in the following step S2. The destination may be input by the user or may be predicted by another device. In the following step S3, the processor 10 acquires various detection information including the map information 3 by the route planning unit 130. In the following step S4, the processor 10 sets a driving lane (or a driving route) for the destination set by the destination setting unit 120 by the route planning unit 130. The processor 10 sets the driving lane by the route planning unit 130 using the map information 3 and the self-position information as well as information obtained from the environment recognition device 5 and the object recognition device 6. The processor 10 sets the road on which the vehicle will travel by the route planning unit 130, but is not limited to the road, and sets the lane on which the vehicle will travel within the road.

In the next step S5, the processor 10 executes a process of planning the driving behavior of the vehicle at each point on the route using the driving plan unit 140. The driving plan specifies driving behavior such as proceed (GO) or stop (No-GO) at each point. For example, when turning right at an intersection, it executes a determination as to whether to stop at the stop line and a determination as to whether to proceed with respect to vehicles in the oncoming lane.

In the next step S6, in order to execute the driving action planned in step S5, the processor 10 executes a process in which the drivable area calculation unit 150 calculates the drivable area around the vehicle (also called the drivable area) using the map information 3, the vehicle's own position information, and information obtained from the environment recognition device 5 and the object recognition device 6. The drivable area is not limited to the lane in which the vehicle is traveling, but may be a lane adjacent to the lane in which the vehicle is traveling (also called an adjacent lane). In addition, the drivable area may be an area in which the vehicle can travel, and may be an area of the road other than that recognized as a lane.

In the next step S7, the processor 10 executes a process of generating a target driving route along which the vehicle will travel, using the route calculation unit 160. In addition, the processor 10 calculates a target vehicle speed and a profile of the target vehicle speed when traveling along the target driving route, using the driving behavior control unit 170. The processor 10 may calculate a target deceleration and target acceleration for the current vehicle speed, and their profiles, instead of or in addition to the target vehicle speed. The calculated target vehicle speed may be fed back to the target driving route generation process to generate a target driving route so as to suppress changes in the vehicle's behavior and movements (behaviors) that may cause the vehicle's occupants to feel uncomfortable. The generated target driving route may be fed back to the target vehicle speed calculation process to calculate the target vehicle speed so as to suppress changes in the vehicle's behavior and movements (behaviors) that may cause the vehicle's occupants to feel uncomfortable.

In step S8, the processor 10 executes a process of formulating a driving plan for driving the vehicle along the generated target driving route. The processor 10 also executes a process of formulating a driving plan for driving the vehicle at the calculated target vehicle speed. Then, in step S9, the output device 110 of the processor 10 outputs control commands and control command values based on the driving plan to the vehicle control device 200 via the communication device 111, and operates the drive mechanism 210, which is a variety of actuators.

The vehicle control device 200 inputs longitudinal and lateral forces that control the vehicle's driving position based on command values from the processor 10. In accordance with these inputs, the vehicle body behavior and wheel behavior are controlled so that the vehicle drives autonomously while following a target driving route. Based on these controls, at least one of the drive actuator and brake actuator of the vehicle body drive mechanism 210, and if necessary, the steering actuator of the steering device, operate autonomously, and autonomous driving control is performed to reach the destination. Of course, the drive mechanism 210 can also be operated according to command values based on manual operation.

[Setting target distance]
In the driving support device 100 of this embodiment, the route calculation unit 160 calculates a target driving route and a target vehicle speed profile in the driving area calculated by the driving area calculation unit 150. In the calculation process of the target driving route, in order to avoid contact between the vehicle and another vehicle, the stopping position of the vehicle is set so as to leave a predetermined distance between the vehicle and the preceding vehicle. Hereinafter, the calculation process of the target driving route of the driving support device 100 by the route calculation unit 160 will be described using the driving scenes shown in Figs. 10A to 10B as examples. Note that the distance between the vehicle and the preceding vehicle refers to the distance from the front end of the vehicle to the rear end of the preceding vehicle.

Figures 10A and 10B are plan views showing driving scenes assuming driving in an urban area. On the roads shown in Figures 10A and 10B, a vehicle drives from the left side to the right side of the drawings. In the driving scene shown in Figure 10A, the host vehicle V1 is driving at a current position Pc on the host vehicle lane L1, and is to change lanes from the host vehicle lane L1 to the adjacent lane L2. In addition, there is a traffic light ahead of the road on which the host vehicle V1 is driving, and the traffic light indicates a stop signal. In response to the stop signal, other vehicles V3 and V4 are stopped in the host vehicle lane L1, and another vehicle V5 is stopped in the adjacent lane L2. In addition, a preceding vehicle V2 of the host vehicle V1 is driving on the adjacent lane L2, and the preceding vehicle V2 drives from a current position Q1 shown by a solid line to a position Q2 shown by a dashed line, and stops at position Q2 in response to the stop signal.

In such a situation, the driving support device 100 of this embodiment detects the driving position and vehicle speed of the preceding vehicle V2 using a detection device 1 such as an imaging device or a distance measuring device. In addition, the driving position and vehicle speed of the host vehicle V1 are detected using a host vehicle information detection device 4 such as a GPS unit, map information 3, and a vehicle speed sensor. Then, using an environment recognition device 5 and an object recognition device 6, it is determined whether the host vehicle V1 will change lanes to a position behind the preceding vehicle V2 based on the vehicle speed difference between the host vehicle V1 and the preceding vehicle V2 and the positional relationship between the host vehicle V1 and the preceding vehicle V2. For example, if the host vehicle V1 is running parallel to the preceding vehicle V2 at a speed faster than the preceding vehicle V2, it is determined that the host vehicle V1 will change lanes to a position in front of the preceding vehicle V2. On the other hand, if the vehicle speed of the host vehicle V1 is slower than that of the preceding vehicle V2 and the preceding vehicle V2 is running ahead of the host vehicle V1, it is determined that the host vehicle V1 will change lanes to a position behind the preceding vehicle V2.

In the driving scene of FIG. 10A, it is assumed that the host vehicle V1 has determined to change lanes to a position behind the preceding vehicle V2. The host vehicle V1 will change lanes to the rear of the preceding vehicle V2 stopped at position Q2, and the driving support device 100 sets the target inter-vehicle distance between the host vehicle V1 and the preceding vehicle V2 to, for example, the first target inter-vehicle distance D1 shown in FIG. 10B, and sets the stop position Px of the host vehicle V1. The stop position Px can be set to, for example, the position Px shown by the dashed line in FIG. 10B. After setting the stop position Px, the driving support device 100 generates a trajectory Tx traveling from the current position Pc to the stop position Px. For the stop position Px shown in FIG. 10B, for example, the trajectory Tx shown in FIG. 10B can be generated. Then, the driving assistance device 100 autonomously controls the driving behavior of the host vehicle V1 using the vehicle control device 200 via the driving behavior control unit 170 so that the host vehicle V1 drives along the trajectory Tx.

When the host vehicle V1 travels along the trajectory Tx shown in FIG. 10B and stops at the stop position Px, the host vehicle V1 does not approach the preceding vehicle V2 any further in order to make the inter-vehicle distance between the host vehicle V1 and the preceding vehicle V2 less than the first target inter-vehicle distance D1. Therefore, in the autonomous control based on the trajectory Tx, the host vehicle V1 stops straddling the host lane L1 and the adjacent lane L2. As a result, the host vehicle V1 may interfere with the travel of the following vehicle traveling on the host lane L1. In addition, in order for the host vehicle V1 to resume traveling from the stop position Px, the preceding vehicle V2 that has stopped at position Q2 must resume traveling, and until then, the host vehicle V1 will be in an unstable state of being stopped straddling the host lane L1 and the adjacent lane L2.

Therefore, the driving support device 100 of this embodiment is configured so that when the host vehicle V1 stops behind the leading vehicle V2 traveling on the host lane L1 or the adjacent lane L2, the host vehicle V1 does not obstruct traffic of other vehicles such as following vehicles, as shown in Fig. 3. That is, the driving support device 100 of this embodiment detects the leading vehicle V2 traveling ahead of the host vehicle V1 on the host vehicle V1 traveling on the host vehicle lane L1 or the adjacent lane L2 of the host vehicle L1, and when the detected leading vehicle V2 stops and the host vehicle V1 stops behind the leading vehicle V2, the target inter-vehicle distance between the host vehicle V1 and the leading vehicle V2 is set to the first target inter-vehicle distance D1. Then, based on the situation of the host vehicle V1 when the host vehicle V1 stops behind the preceding vehicle V2 at the first target inter-vehicle distance D1, it is determined whether or not the target inter-vehicle distance needs to be set to a second target inter-vehicle distance D2 that is smaller than the first target inter-vehicle distance D1, and if it is determined that the second target inter-vehicle distance D2 needs to be set, the target inter-vehicle distance is set to the second target inter-vehicle distance D2, and the driving of the host vehicle V1 is controlled to adjust the inter-vehicle distance so that the inter-vehicle distance between the host vehicle V1 and the preceding vehicle V2 becomes the second target inter-vehicle distance D2. The autonomous control of the driving operation by the driving assistance device 100 will be described below using the driving scenes shown in Figures 3A to 3B as examples.

Figures 3A-3B are plan views showing driving scenes similar to those in Figures 10A-10B. As in Figure 10A, in the driving scene of Figure 3A, when the host vehicle V1 changes lanes from the host vehicle lane L1 to the adjacent lane L2, the host vehicle V1 changes lanes to the rear of the preceding vehicle V2 stopped at position Q2. The driving support device 100 according to this embodiment sets the target inter-vehicle distance between the host vehicle V1 and the preceding vehicle V2 to a first target inter-vehicle distance D1, sets a first position P1 where the inter-vehicle distance between the host vehicle V1 and the preceding vehicle V2 is the first target inter-vehicle distance D1, and generates a first trajectory T1 that travels from the current position Pc shown by the solid line to the first position P1 shown by the dashed line. The host vehicle V1 travels along the first trajectory T1 shown in Figure 3A by autonomous control and reaches the first position P1.

When the vehicle reaches the first position P1, the driving support device 100 judges whether or not it is necessary to set the target inter-vehicle distance to the second target inter-vehicle distance D2, which is smaller than the first target inter-vehicle distance D1. In this judgment, the route calculation unit 160 of the driving support device 100 judges, for example, whether the lane change of the vehicle V1 has been completed. If the lane change from the vehicle's own lane L1 to the adjacent lane L2 has been completed at the time of reaching the first position P1, the vehicle does not interfere with the traffic of other vehicles and there is no need to further shorten the inter-vehicle distance, so the target inter-vehicle distance is set to the first target inter-vehicle distance D1. On the other hand, if the vehicle V1 is unable to complete the lane change from the vehicle's own lane L1 to the adjacent lane L2 and stops behind the preceding vehicle V2 in a state of straddling lanes, for example, there is a risk of interfering with the traffic of other vehicles, so the target inter-vehicle distance is set to the second target inter-vehicle distance D2, which is shorter than the first target inter-vehicle distance D1. In the driving scene shown in FIG. 3A, the lane change has not been completed, so as shown in FIG. 3B, a second target inter-vehicle distance D2 that is shorter than the first target inter-vehicle distance D1 is set as the target inter-vehicle distance, thereby preventing the traffic of other vehicles traveling in the own lane L1 from being disrupted.

Alternatively, when determining whether or not it is necessary to set the target inter-vehicle distance to the second target inter-vehicle distance D2, the vehicle stop position where the host vehicle V1 will stop may be calculated from the detected vehicle speed difference between the host vehicle V1 and the preceding vehicle V2 and the positional relationship between the host vehicle V1 and the preceding vehicle V2 when determining whether or not it is necessary to set the second target inter-vehicle distance D2, and the vehicle stop position may be used to determine whether or not it is necessary to set the second target inter-vehicle distance D2. For example, if it is determined that stopping at the calculated stop position will result in stopping across the host vehicle lane L1 and the adjacent lane L2, the driving assistance device 100 sets the target inter-vehicle distance to the second target inter-vehicle distance D2.

The driving support device 100 sets a second position P2 where the inter-vehicle distance between the host vehicle V1 and the preceding vehicle V2 is a second target inter-vehicle distance D2, and generates a second trajectory T2 along which the host vehicle V1 travels from the first position P1 shown by a solid line to the second position P2 shown by a dashed line in FIG. 3B. The host vehicle V1 travels along the second trajectory T2 shown in FIG. 3B, for example, by autonomous control, and reaches the second position P2. As a result, the host vehicle V1 will be fully inside the adjacent lane L2 when it stops at the second position P2, and there will be no risk of interfering with the travel of the following vehicle Vf of the host vehicle V1 traveling on the host vehicle lane L1. In this embodiment, the host vehicle V1 being fully inside the adjacent lane L2 means that the entire body of the host vehicle V1 is included in the adjacent lane L2 when the host vehicle V1 is viewed from above.

[Setting unsuitable stopping areas]
In the example of Fig. 3, the host vehicle V1 stops at the distance of the first target inter-vehicle distance D1 from the rear of the preceding vehicle V2, and is unable to complete lane change from the host vehicle lane L1 to the adjacent lane L2. Therefore, it is determined that the target inter-vehicle distance needs to be set to the second target inter-vehicle distance D2 based on the surrounding conditions of the stopped host vehicle V1. However, the criteria for determining whether or not the target inter-vehicle distance D2 needs to be set are not limited to the example of Fig. 3. For example, as shown in Fig. 4A, in a drivable area R1, which is an area in which the host vehicle V1 can travel, a stopping inappropriate area R2, which is an area in which the host vehicle V1 stops and obstructs traffic of traffic participants other than the host vehicle V1, such as other vehicles or pedestrians, is set, and it is determined whether or not a part of the host vehicle V1 is included in the stopping inappropriate area R2. If it is determined that a part of the host vehicle V1 is included in the stopping inappropriate area R2, the second target inter-vehicle distance D2 can be set. Hereinafter, the stopping inappropriate area R2 will be described using the examples shown in Figs. 4A to 4E. Additionally, a method for determining whether or not it is necessary to set the second target inter-vehicle distance D2 based on the situation of other vehicles or pedestrians around the host vehicle V1 will also be described.

Figure 4A is a plan view showing an example of an inappropriate stopping area R2 when the host vehicle V1 changes lanes from the host lane L1 to the adjacent lane L2. Figure 4A is a plan view showing a driving scene similar to that shown in Figures 3A and 3B, in which the preceding vehicle V2 has already stopped and the host vehicle V1 has reached the first position P1.

When calculating the unsuitable stopping area R2, the drivable area calculation unit 150 of the driving support device 100 sets the drivable area R1 shown by the dashed line in FIG. 4A. For example, the drivable area R1 is set to an area of the lane of the road on which the vehicle V1 is traveling, where the vehicle V1 does not come into contact with other vehicles that are stopped. In the case of the drivable area R1 shown in FIG. 4A, an area of the vehicle lane L1 and the adjacent lane L2 where the rear ends of the stopped preceding vehicles V2 and other vehicles V3 can be avoided from coming into contact with the front end of the vehicle V1 is set as the drivable area R1. In order to prevent the rear ends of the stopped preceding vehicles V2 and other vehicles V3 from coming into contact with the front end of the vehicle V1, the front end E1 of the drivable area R1 in the driving direction is set to a position with a predetermined distance from the rear ends of the preceding vehicles V2 and other vehicles V3. The predetermined distance is an appropriate distance that can avoid contact between the vehicle V1 and the preceding vehicles V2 and other vehicles V3.

Next, the route calculation unit 160 of the driving support device 100 sets the unsuitable stopping area R2. As the unsuitable stopping area R2, for example, an area of the lane of the road on which the host vehicle V1 is traveling is set, in the drivable area R1, where the host vehicle V1 will obstruct the traffic of other vehicles if it stops. In the driving scene shown in FIG. 4A, the host vehicle V1 changes lanes from the host vehicle lane L1 to the adjacent lane L2. At this time, if the host vehicle V1 stops in the host vehicle lane L1 without completing the lane change, it will obstruct the traffic of the following vehicle Vf traveling in the host vehicle lane L1. Therefore, in this case, the hatched area in the host vehicle lane L1 of the drivable area R1 shown by the dashed line in FIG. 4A is set as the unsuitable stopping area R2.

The driving assistance device 100 then determines whether or not at least a portion of the host vehicle V1 is included in the unsuitable stopping area R2. This determination is made using a detection device 1, such as an imaging device or a distance measuring device, and a host vehicle information detection device 4. Specifically, the determination is made using the distance between the host vehicle V1 and the lane recognized by the imaging device, and the distance between the host vehicle V1 and a curb on the road detected by the distance measuring device. If it is determined that the host vehicle V1 is not included in the unsuitable stopping area R2, the target inter-vehicle distance is not set to the second target inter-vehicle distance D2, and the host vehicle V1 is stopped at the first position P1 shown by a solid line in FIG. 4A. On the other hand, as shown in FIG. 4A, when it is determined that at least a part of the host vehicle V1 is included in the unsuitable stopping area R2, the driving support device 100 sets a second position P2 where the inter-vehicle distance between the host vehicle V1 and the preceding vehicle V2 is a second target inter-vehicle distance D2, and generates a second trajectory T2 that travels from the first position P1 shown by the solid line to the second position P2 shown by the dashed line. By traveling along the second trajectory T2 by autonomous control in this way, the host vehicle V1 can move to a position that is not included in the unsuitable stopping area R2, and there is no risk of impeding the travel of the following vehicle Vf traveling in the host vehicle lane L1.

Figure 4B is a plan view showing an example of an unsuitable stopping area R2 when the vehicle's lane L1 branches into a main line and a branch line ahead in the driving direction. On the road shown in Figure 4B, the vehicle travels from the left side to the right side of the drawing. The road on which the vehicle V1 travels includes the vehicle's lane L1 and an adjacent lane L2, and the vehicle's lane L1 branches into the main lane L1 and a branch line Lb at a branch point B. In addition, there is a traffic light ahead in the driving direction on the road shown in Figure 4B, and the traffic light is showing a stop signal such as a red light.

In the driving scene of FIG. 4B, the host vehicle V1 travels on the host lane L1 from the left side to the right side of the drawing, and enters the branch line Lb from the host lane L1. Another vehicle V3 is stopped on the branch line Lb in response to a stop signal, and a preceding vehicle V2 that has entered the branch line Lb from the host lane L1 is stopped behind the other vehicle V3. In this case, when the host vehicle V1 enters the branch line Lb from the host lane L1, the host vehicle V1 will enter behind the stopped preceding vehicle V2 on the branch line Lb. At this time, the driving support device 100 sets the target inter-vehicle distance between the host vehicle V1 and the preceding vehicle V2 to the first target inter-vehicle distance D1, sets a first position P1 where the inter-vehicle distance between the host vehicle V1 and the preceding vehicle V2 is the first target inter-vehicle distance D1, and generates a trajectory from the current position to the first position P1. The vehicle V1 then travels along the generated trajectory and reaches the first position P1.

When the host vehicle V1 reaches the first position P1, the driving support device 100 uses the unsuitable stopping area R2 to determine whether or not it is necessary to set the target inter-vehicle distance to a second target inter-vehicle distance D2 that is smaller than the first target inter-vehicle distance D1. First, the driving support device 100 sets the drivable area R1 shown by the dashed line in FIG. 4B. The drivable area R1 can be set in the same manner as in the scene shown in FIG. 4A. In the driving scene shown in FIG. 4B, the drivable area R1 is set to an area among the host vehicle lane L1, the adjacent lane L2, and the branch line Lb in which contact between the rear end of the stopped preceding vehicle V2 and the front end of the host vehicle V1 can be avoided.

Next, the driving assistance device 100 sets the unsuitable stopping area R2. The unsuitable stopping area R2 can be set in the same manner as the scene shown in FIG. 4A. In the driving scene shown in FIG. 4B, the host vehicle V1 enters the branch line Lb from the host lane L1. If the host vehicle V1 stops in the host lane L1 without completing the entry into the branch line Lb, the vehicle V1 will obstruct the traffic of the following vehicle Vf traveling in the host lane L1. Therefore, in this case, the region of the host lane L1 out of the drivable area R1 is set as the unsuitable stopping area R2. That is, in FIG. 4B, the area indicated by the dashed line and hatched is the unsuitable stopping area R2.

Then, the driving support device 100 judges whether or not at least a part of the host vehicle V1 is included in the unsuitable stopping area R2. The judgment method is the same as that of the driving scene shown in FIG. 4A. If it is judged that the host vehicle V1 is not included in the unsuitable stopping area R2, the target inter-vehicle distance is not set to the second target inter-vehicle distance D2. On the other hand, as shown in FIG. 4B, if it is judged that at least a part of the host vehicle V1 is included in the unsuitable stopping area R2, the driving support device 100 sets the target inter-vehicle distance to the second target inter-vehicle distance D2, sets a second position P2 where the inter-vehicle distance between the host vehicle V1 and the preceding vehicle V2 is the second target inter-vehicle distance D2, and generates a second trajectory T2 that travels from the first position P1 shown by the solid line in FIG. 4B to the second position P2 shown by the dashed line. Then, the host vehicle V1 travels along the second trajectory T2 to the second position P2, moving to a position that is not included in the unsuitable stopping area R2, and will no longer impede the travel of the following vehicle Vf traveling in the host vehicle lane L1.

The case where the vehicle V1 enters the branch line Lb from the vehicle lane L1 has been described with reference to FIG. 4B. In contrast, the case where the vehicle V1 continues to travel on the vehicle lane L1, which is the main line, after passing the branch point B will be described below with reference to FIG. 4C. In the travel scene of FIG. 4C, the vehicle V3 is stopped in the vehicle lane L1, the vehicles V4 and V5 are stopped in the adjacent lane L2, and the preceding vehicle V2 is stopped behind the other vehicle V3, following a stop signal. In this case, the vehicle V1 traveling on the vehicle lane L1 will stop behind the preceding vehicle V2 stopped on the vehicle lane L1. Therefore, the driving support device 100 sets the target inter-vehicle distance between the vehicle V1 and the preceding vehicle V2 to the first target inter-vehicle distance D1, sets the first position P1 at which the inter-vehicle distance between the vehicle V1 and the preceding vehicle V2 is the first target inter-vehicle distance D1, and generates a trajectory from the current travel position to the first position P1. The vehicle V1 travels along the generated trajectory and reaches the first position P1.

When the host vehicle V1 reaches the first position P1, the driving support device 100 uses the unsuitable stopping area R2 to determine whether or not it is necessary to set the target inter-vehicle distance to the second target inter-vehicle distance D2. First, the driving support device 100 sets the drivable area R1 shown by the dashed line in FIG. 4C. The setting of the drivable area R1 is the same as that in the scene shown in FIG. 4B. In the driving scene shown in FIG. 4C, the drivable area R1 is set to an area among the host vehicle lane L1, adjacent lane L2, and branch line Lb in which contact between the rear ends of the stopped preceding vehicle V2 and other vehicle V4 and the front end of the host vehicle V1 can be avoided.

Next, the driving assistance device 100 sets the unsuitable stopping area R2. The unsuitable stopping area R2 can be set in the same manner as the scene shown in FIG. 4B. In the driving scene shown in FIG. 4B, the vehicle V1 travels in the own lane L1 even after passing the branch point B. In this case, at the branch point B between the own lane L1 and the branch line Lb, the following vehicle Vf attempts to enter the branch line Lb from the own lane L1, but if the own vehicle V1 stops at the branch point B, it becomes an obstacle and the following vehicle Vf cannot enter the branch line Lb. Therefore, in the driving scene shown in FIG. 4C, the region of the branch line Lb and the region in the own lane L1 where the following vehicle Vf entering the branch line Lb from the own lane L1 travels to enter the branch line Lb are set as the unsuitable stopping area R2. The area of the branch line Lb is, for example, the hatched area R2a shown by a dashed line in FIG. 4C, and the area through which the following vehicle Vf travels to enter the branch line Lb is, for example, the hatched area R2b shown by a dashed line in FIG. 4C.

Then, the driving support device 100 judges whether or not at least a part of the host vehicle V1 is included in the unsuitable stopping area R2. The judgment method is the same as the driving scene shown in FIG. 4B. If it is judged that at least a part of the host vehicle V1 is not included in the unsuitable stopping area R2, the second target inter-vehicle distance D2 is not set. On the other hand, as shown in FIG. 4C, if it is judged that a part (or all) of the host vehicle V1 is included in the unsuitable stopping area R2, the driving support device 100 sets the target inter-vehicle distance to the second target inter-vehicle distance D2, sets a second position P2 where the inter-vehicle distance between the host vehicle V1 and the preceding vehicle V2 is the second target inter-vehicle distance D2, and generates a second trajectory T2 that travels from the first position P1 shown by the solid line in FIG. 4C to the second position P2 shown by the dashed line. By traveling to the second position P2 along the second trajectory T2, the host vehicle V1 can move to a position that is not included in the unsuitable stopping area R2. As a result, the following vehicle Vf entering the branch line Lb from the own lane L1 does not need to stop temporarily at position Pf1 in order to enter the branch line Lb. In other words, by moving the own vehicle V1 to the second position P2, the following vehicle Vf can pass behind the own vehicle V1 without stopping and travel from position Pf1 of the own lane L1 to position Pf2 of the branch line Lb, for example, along the trajectory Tf.

Figure 4D is a plan view showing an example of an unsuitable stopping area R2 when the vehicle V1 is traveling in an urban area. On the road shown in Figure 4D, the vehicle travels from the left to the right of the drawing. The road on which the vehicle V1 is traveling has two lanes, the vehicle's own lane L1 and the adjacent lane L2, and there is an intersection C that intersects with other roads. A pedestrian crossing CW1 is located ahead of the intersection C in the direction of travel, and a pedestrian crossing CW2 is located behind the intersection C in the direction of travel. In addition, a stop-prohibited area NS exists on the adjacent lane L2 side ahead of the pedestrian crossing CW1 in the direction of travel. At this time, another vehicle V3 is stopped in the vehicle's own lane L1, and a leading vehicle V2 is stopped behind the other vehicle V3. In this embodiment, the stop-prohibited area refers to an area where the vehicle can pass inside the sign, but cannot stop within the sign, such as an area installed in front of a fire station on a road.

In the driving scene shown in FIG. 4D, the host vehicle V1 travels from the left side of the drawing to the right side on the host vehicle lane L1, passes through the intersection C, and stops at the first position P1 where the inter-vehicle distance from the preceding vehicle V2 is the first target inter-vehicle distance D1. When the host vehicle V1 reaches the first position P1 shown by the solid line, the driving support device 100 determines whether or not it is necessary to set the target inter-vehicle distance to the second target inter-vehicle distance D2 by using the stopping inappropriate region R2. First, the driving support device 100 sets the drivable region R1 shown by the dashed line in FIG. 4D. The drivable region R1 can be set in the same way as in the scene shown in FIG. 4A. In the driving scene shown in FIG. 4D, the drivable region R1 is set to an area in the host vehicle lane L1 and the adjacent lane L2 where the rear end of the stopped preceding vehicle V2 can avoid contact with the front end of the host vehicle V1.

Next, the driving support device 100 sets the unsuitable stopping areas R2a to R2d. In the driving scenes shown in Figures 4A, 4B, and 4C, the unsuitable stopping area R2 was set for one other vehicle, but in the driving scene shown in Figure 4D, multiple unsuitable stopping areas are set for each traffic participant, such as a vehicle or a pedestrian. First, for the intersection C, if the vehicle V1 stops in the intersection C, it will obstruct the traffic of vehicles traveling on other roads. Therefore, in Figure 4D, the unsuitable stopping area R2a, which is hatched and shown by a dashed line, is set at the position of the intersection C in the drivable area R1. In addition, for the crosswalks CW1 and CW2, if the vehicle V1 stops in the crosswalk CW1 or CW2, it will obstruct pedestrians crossing the road on which the vehicle V1 is traveling through the crosswalk CW1 or CW2. Therefore, hatched and unsuitable stopping areas R2b and R2c are set at the positions of the crosswalks CW1 and CW2 within the drivable area R1. Furthermore, with regard to the stopping prohibition portion NS, if the host vehicle V1 were to stop in the stopping prohibition portion NS, the host vehicle V1 would become an obstacle, and emergency vehicles such as fire engines and ambulances would not be able to be dispatched. Therefore, a hatched and unsuitable stopping area R2d is set at the position of the stopping prohibition portion NS.

Then, the driving support device 100 judges whether or not at least a part of the host vehicle V1 is included in the unsuitable stopping area R2. The judgment method is the same as that of the driving scene shown in FIG. 4A. If it is judged that at least a part of the host vehicle V1 is not included in the unsuitable stopping area R2, the target inter-vehicle distance is not set to the second target inter-vehicle distance D2. On the other hand, as shown in FIG. 4D, if it is judged that a part (or all) of the host vehicle V1 is included in the unsuitable stopping area R2b set for the crosswalk CW1, the driving support device 100 sets the target inter-vehicle distance to the second target inter-vehicle distance D2, sets a second position P2 where the inter-vehicle distance between the host vehicle V1 and the preceding vehicle V2 is the second target inter-vehicle distance D2, and generates a second trajectory T2 that travels from the first position P1 shown by the solid line to the second position P2 shown by the dashed line. By traveling along the second trajectory T2 to the second position P2, the vehicle V1 can move to a position where the rear of the vehicle V1 is not included in the crosswalk CW1. This allows the vehicle V1 to avoid blocking pedestrians from crossing the road at the crosswalk CW1.

Figure 4E is a plan view showing another example of an unsuitable stopping area R2 when the vehicle V1 is traveling in an urban area. The road shown in Figure 4E has two lanes, and a vehicle traveling in the vehicle lane L1 travels from the left to the right of the drawing, and a vehicle traveling in the oncoming lane Lo travels from the right to the left of the drawing. In addition, a sidewalk SW is present on the left side of the vehicle lane L1 in the traveling direction, and facilities F1 and F2, such as stores and public facilities, where vehicles can enter, are located adjacent to the sidewalk. At this time, a preceding vehicle V2a is stopped in the vehicle lane L1, and an oncoming vehicle Vo is traveling in the oncoming lane Lo. In addition, the oncoming vehicle Vo is traveling at the current position Po1, and in order to enter the facility F1, it is assumed that the oncoming vehicle Vo travels along a trajectory To from the current position Po1 shown by the solid line to the position Po2 shown by the dashed line. At that time, the oncoming vehicle Vo crosses the vehicle lane L1 and the sidewalk SW.

In the driving scene shown in FIG. 4E, the host vehicle V1a travels from the left side to the right side of the drawing on the host lane L1 and stops at a first position P1a where the distance between the host vehicle V1a and the preceding vehicle V2a is the first target distance D1. When the host vehicle V1 reaches the first position P1a, the driving support device 100 determines whether or not it is necessary to set the target distance to the second target distance D2 using the unsuitable stopping area R2. To do this, the driving support device 100 first sets a drivable area R1 shown by a dashed line in FIG. 4E. The drivable area R1 can be set in the same way as in the scene shown in FIG. 4A. In the driving scene shown in FIG. 4E, the drivable area R1 is set as an area of the host lane L1 where the rear end of the stopped preceding vehicle V2a and the front end of the host vehicle V1a can be avoided. In addition, because the vehicle V1a must cross the sidewalk SW when entering facilities F1 and F2, the portion of the sidewalk SW adjacent to facilities F1 and F2 is also set as part of the drivable area R1.

Next, the driving support device 100 sets the unsuitable stopping area R2a. The unsuitable stopping area R2 is an area in the drivable area R1 where the vehicle V1 stops and obstructs the traffic of other traffic participants. If the vehicle V1 stops at a position where the facility F1 is present on the left side of the driving direction, that is, in front of the facility F1, the oncoming vehicle Vo cannot enter the facility F1 because the vehicle V1 becomes an obstacle. Therefore, the driving support device 100 sets the unsuitable stopping area R2 in the drivable area R1 where the oncoming vehicle Vo entering the facility F1 travels along the trajectory To. In the case of the driving scene shown in FIG. 4E, for example, the hatched area R2a shown by the dashed line in FIG. 4E is set as the unsuitable stopping area. When the unsuitable stopping area R2 is set in consideration of the surrounding driving environment such as the sidewalk SW and the facility F1 as in the driving scene shown in FIG. 4E, in addition to the detection result of the detection device 1, map information 3 such as high-definition map information can be used.

Then, the driving support device 100 judges whether or not at least a part of the host vehicle V1 is included in the unsuitable stopping area R2a. This judgment method is the same as the driving scene shown in FIG. 4A, but when the surrounding driving environment is taken into consideration as in the driving scene shown in FIG. 4E, not only the detection result of the detection device 1 but also map information 3 such as high-definition map information and the detection result of the host vehicle information detection device 4 can be used. If it is determined that at least a part of the host vehicle V1 is not included in the unsuitable stopping area R2a, the target inter-vehicle distance is not set to the second target inter-vehicle distance D2. On the other hand, as shown in FIG. 4E, if it is determined that a part (or all) of the host vehicle V1 is included in the unsuitable stopping area R2a, the driving support device 100 sets the target inter-vehicle distance to the second target inter-vehicle distance D2 and sets the second position P2a where the inter-vehicle distance between the host vehicle V1a and the preceding vehicle V2a is the second target inter-vehicle distance D2. Then, a second trajectory T2a is generated that travels from a first position P1a shown by a solid line in FIG. 4E to a second position P2a shown by a dashed line. By traveling along the second trajectory T2a to the second position P2a, the host vehicle V1a can move to a position where it does not become an obstacle when an oncoming vehicle Vo enters the facility F1.

In the driving scene shown in FIG. 4E, when an oncoming vehicle Vo enters facility F1, the area through which the oncoming vehicle Vo travels to enter facility F1 is set as an unsuitable stopping area R2a. On the other hand, when the host vehicle V1 enters the facility, the sidewalk SW between the road on which the host vehicle V1 travels and the facility is set as an unsuitable stopping area.

For example, in the driving scene shown in FIG. 4E, assume that the host vehicle V1b traveling in the host vehicle lane L1 is about to turn left and enter facility F2 when a leading vehicle V2b is stopped ahead of the host vehicle V1b. Also, assume that the host vehicle V1b stops at a first position P1b shown by a solid line where the vehicle distance from the leading vehicle V2b is the first target vehicle distance D1, in order to set the vehicle distance from the leading vehicle V2b to the first target vehicle distance D1 that has already been set. In this case, the rear of the host vehicle V1b will extend onto the sidewalk SW, obstructing the passage of pedestrians on the sidewalk SW. Therefore, as shown in FIG. 4E, the driving support device 100 sets the area of the sidewalk SW adjacent to facility F2 in the drivable area R1 as an unsuitable stopping area R2b.

Then, the driving support device 100 judges whether or not at least a part of the host vehicle V1b is included in the unsuitable stopping area R2b. This judgment method is the same as when the oncoming vehicle Vo enters the facility F1. If it is judged that at least a part of the host vehicle V1b is not included in the unsuitable stopping area R2b, the target inter-vehicle distance is not set to the second target inter-vehicle distance D2. On the other hand, as shown in FIG. 4E, if it is judged that a part (or all) of the host vehicle V1b is included in the unsuitable stopping area R2b, the driving support device 100 sets the target inter-vehicle distance to the second target inter-vehicle distance D2, sets a second position P2b where the inter-vehicle distance between the host vehicle V1b and the preceding vehicle V2b is the second target inter-vehicle distance D2, and generates a second trajectory T2b that travels from the first position P1b shown by the solid line to the second position P2b shown by the dashed line. By traveling along the second trajectory T2b to the second position P2b, the host vehicle V1b can move to a position where it does not obstruct pedestrians on the sidewalk SW.

[Setting of target inter-vehicle distance by following vehicle]
When the driving support device 100 of the present embodiment detects a following vehicle Vf following the host vehicle V1, the driving support device 100 determines whether or not at least a part of the following vehicle Vf is included in the unsuitable stopping region R2, and when it is determined that a part or all of the following vehicle Vf following the host vehicle V1 is included in the unsuitable stopping region R2, the target inter-vehicle distance may be set to the second target inter-vehicle distance D2 so that the following vehicle Vf is not included in the unsuitable stopping region R2. This makes it possible to prevent the following vehicle Vf following the host vehicle V1 from interfering with the running of other vehicles following further behind. Hereinafter, a method of adjusting the inter-vehicle distance based on the following vehicle Vf and the unsuitable stopping region R2 will be described with reference to FIGS. 5A to 5B.

Figures 5A and 5B are plan views showing driving scenes assuming driving in an urban area. On the roads shown in Figures 5A and 5B, a vehicle drives from the left side to the right side of the drawings, and there is a traffic light ahead of the roads shown in Figures 5A and 5B, and the traffic light is indicating a stop signal. In the driving scene shown in Figure 5A, the host vehicle V1 changes lanes to the rear of the preceding vehicle V2 and stops at the first position P1 shown by a solid line. Specifically, when other vehicles V3 and V4 are stopped in the host vehicle lane L1 in response to a stop signal, the host vehicle V1 drives in the host vehicle lane L1, the preceding vehicle V2 drives in the adjacent lane L2, and after the preceding vehicle V2 stops in response to the stop signal, the host vehicle V1 changes lanes to the rear of the preceding vehicle V2 and stops at the first position P1.

Here, when the vehicle V1 changes lanes from the own lane L1 to the adjacent lane L2, the driving area R1 shown by the dashed line in FIG. 5A and the stopping unsuitable area R2 shown by the dashed line and hatched are set, as in the case shown in FIG. 4A. Furthermore, a following vehicle Vf traveling at a current position Pf1 shown by a solid line exists in the own lane L1, and this following vehicle Vf changes lanes from the own lane L1 to the adjacent lane L2. In this case, when the following vehicle Vf changes lanes from the own lane L1 to the adjacent lane L2, it changes lanes to the rear of the own vehicle V1 stopped at the position P1 shown by the solid line. At that time, the following vehicle Vf changes lanes along the trajectory Tf, but in order to secure a distance between the vehicle V1 and the following vehicle V1, it may stop at the position Pf2 shown by the dashed line, for example, and not be able to complete the lane change. As a result, the following vehicle Vf may stop at position Pf2, which is included in the unsuitable stopping area R2 set by the host vehicle V1, and may impede the travel of other vehicles following behind the following vehicle Vf.

In this embodiment, when the driving support device 100 detects the following vehicle Vf shown in FIG. 5A by the detection device 1, it determines whether or not at least a part of the following vehicle Vf is included in the unsuitable stopping area R2 set when the host vehicle V1 changes lanes. For this determination, the detection device 1, such as an imaging device or a distance measuring device, the environment recognition device 5, and the object recognition device 6 can be used. For example, the imaging device is used to recognize the traveling position of the following vehicle Vf in the host lane L1. If it is determined that a part or all of the following vehicle Vf is not included in the unsuitable stopping area R2, the target inter-vehicle distance is not set to the second target inter-vehicle distance D2. On the other hand, if it is determined that a part or all of the following vehicle Vf is included in the unsuitable stopping area R2, the target inter-vehicle distance is set to the second target inter-vehicle distance D2 so that the following vehicle Vf is not included in the unsuitable stopping area R2. For example, the driving assistance device 100 sets a second position P2 shown by a dashed line in FIG. 5A, and generates a second trajectory T2 traveling from the first position P1 to the second position P2.

The host vehicle V1 travels along the second trajectory T2 and stops at the second position P2 shown by the solid line in FIG. 5B. This allows the host vehicle V1 to approach the leading vehicle V2 and close the distance between the leading vehicle V2. As the host vehicle V1 moves forward in this way, a space is created behind the host vehicle V1 in the adjacent lane L2 for the following vehicle Vf to travel. The following vehicle Vf can stop at a position that is not included in the unsuitable stopping area R2 by traveling along the trajectory Tf, for example, from position Pf2 shown by the solid line in FIG. 5B to position Pf3 shown by the dashed line within that space. As a result, the following vehicle Vf will no longer impede the travel of other vehicles following behind.

In the example shown in Figures 5A-5B, a method for setting the second target inter-vehicle distance D2 by the following vehicle Vf has been described assuming that the following vehicle Vf is actually detected. However, the presence of the following vehicle Vf may be assumed before the following vehicle is detected, and it may be determined whether or not at least a portion of the assumed following vehicle Vf is included in the unsuitable stopping area R2. If it is determined that at least a portion of the assumed following vehicle Vf is included in the unsuitable stopping area R2, the target inter-vehicle distance between the host vehicle V1 and the preceding vehicle V2 is set to the second target inter-vehicle distance D2 so that the entire assumed following vehicle Vf is not included in the unsuitable stopping area R2.

[Adjusting distance]
The driving support device 100 of this embodiment does not necessarily have to reach the set second position P2 when traveling along the second locus T2. In other words, when it is determined that it is no longer necessary to shorten the inter-vehicle distance between the host vehicle V1 and the leading vehicle V2 during traveling from the first position P1 to the second position P2, such as when there is no longer a risk of interfering with the traveling of the following vehicle Vf traveling on the host vehicle lane L1, the host vehicle V1 may stop before the second position P2. Hereinafter, a method of adjusting the inter-vehicle distance will be described with reference to Figures 6A to 6C. In this embodiment, slow driving refers to traveling at a speed (for example, 5 to 10 km/h) at which the host vehicle can immediately stop.

Figures 6A to 6C are driving scenes that assume driving in an urban area, and on the roads shown in Figures 6A to 6C, a vehicle drives from the left side to the right side of the drawing. Also, there is a traffic light ahead of the roads shown in Figures 6A to 6C, and the traffic light is indicating a stop signal. In the driving scene shown in Figure 6A, other vehicles V3 and V4 are stopped in the own lane L1, and other vehicle V5 is stopped in the adjacent lane L2 in response to the stop signal. At this time, leading vehicle V2 drives from the left side to the right side of the drawing on the adjacent lane L2 and stops behind other vehicle V5, and after leading vehicle V2 has stopped, the own vehicle V1 changes lanes from the own lane L1 to the adjacent lane L2, to a position behind leading vehicle V2.

In this case, the driving support device 100 of this embodiment sets the target inter-vehicle distance between the host vehicle V1 and the preceding vehicle V2 to the first target inter-vehicle distance D1, sets a first position P1 where the inter-vehicle distance between the host vehicle V1 and the preceding vehicle V2 is the first target inter-vehicle distance D1, and generates a first trajectory T1 along which the host vehicle V1 travels from the current position Pc shown by the solid line to the first position P1 shown by the dashed line. Here, the first trajectory T1 shown in FIG. 6A is set so that the steering to the right starts earlier and the amount of steering is smaller than that shown in FIG. 3A. Therefore, the attitude of the host vehicle V1 when traveling along the first trajectory T1 and reaching the first position P1 has a smaller inclination of the vehicle body with respect to the traveling direction when viewed from above (i.e., the yaw angle formed by the traveling direction of the road and the center line of the host vehicle V1) than that shown in FIG. 3A, and the portion included in the host vehicle lane L1 is smaller.

When the vehicle reaches the first position P1, the driving support device 100 judges whether or not it is necessary to set the target inter-vehicle distance to the second target inter-vehicle distance D2. For example, if the judgment is based on whether or not the lane change has been completed as in the case of Figs. 3A-3B, the lane change has not been completed in the driving scene shown in Fig. 6A, so the target inter-vehicle distance is set to the second target inter-vehicle distance D2. Here, the second target inter-vehicle distance D2 is set to the shortest distance that can be set as the target inter-vehicle distance, for example, as shown in Fig. 6B. After setting the second target inter-vehicle distance D2, a second position P2 is set at which the inter-vehicle distance between the vehicle V1 and the preceding vehicle V2 is the shortest distance that can be set, and a second trajectory T2 is generated that travels from the first position P1 shown by the solid line in Fig. 6B to the second position P2 shown by the dashed line. Then, the vehicle V1 travels to the second position P2 along the second trajectory T2, and thus does not interfere with the travel of the following vehicle Vf shown in Fig. 6B.

However, in order for the host vehicle V1 to completely enter the adjacent lane L2, the host vehicle V1 does not necessarily have to approach the leading vehicle V2 to the second target inter-vehicle distance D2 shown in Fig. 6B. For example, if the host vehicle V1 travels along the second trajectory T2 shown in Fig. 6B and reaches the third position P3 shown by the dashed line in Fig. 6C, at that point the host vehicle V1 will have completely entered the adjacent lane L2 and will not interfere with the travel of the following vehicle Vf traveling in the host vehicle lane L1. Therefore, in order to adjust the inter-vehicle distance as necessary, the driving assistance device 100 of this embodiment stops the host vehicle V1 at a first position P1 where the inter-vehicle distance between the host vehicle V1 and the preceding vehicle V2 is a first target inter-vehicle distance D1, then slows down the host vehicle V1 from the first position P1 to a second position P2 where the inter-vehicle distance is a second target inter-vehicle distance D2, and if it is determined during this slow-down that it is no longer necessary to reduce the inter-vehicle distance, stops the host vehicle V1.

In order to determine that it is no longer necessary to shorten the inter-vehicle distance, the driving assistance device 100 determines, for example, whether the lane change of the host vehicle V1 from the own lane L1 to the adjacent lane L2 is completed, or whether at least a part of the host vehicle V1 is included in the unsuitable stopping area R2. In other words, if it is determined that the lane change of the host vehicle V1 from the own lane L1 to the adjacent lane L2 is completed, or if it is determined that the entire host vehicle V1 is not included in the unsuitable stopping area R2, it is determined that it is not necessary to further shorten the inter-vehicle distance with the preceding vehicle V2, and the host vehicle V1 is stopped just before the second position P2. On the other hand, if it is determined that the lane change of the host vehicle V1 from the own lane L1 to the adjacent lane L2 is not completed, or if it is determined that at least a part of the host vehicle V1 is included in the unsuitable stopping area R2, the driving assistance of the host vehicle V1 along the second trajectory T2 is continued. Instead of stopping at the first position P1 and then starting to move slowly, the host vehicle V1 may reach a position a predetermined distance from the first position P1 and then start moving slowly from a position a predetermined distance from the first position P1 without stopping. The predetermined distance is an appropriate distance that allows the host vehicle V1 to maintain a sufficient distance from the preceding vehicle V2 and the following vehicle Vf even when moving slowly.

Alternatively, instead of the second target inter-vehicle distance D2, a third target inter-vehicle distance D3 shown in FIG. 6C, which is shorter than the first target inter-vehicle distance D1 and longer than the second target inter-vehicle distance D2, may be set as the target inter-vehicle distance, a third position P3 may be set at which the inter-vehicle distance between the host vehicle V1 and the preceding vehicle V2 is the third target inter-vehicle distance D3, a third trajectory T3 running from the first position P1 to the third position P3 may be generated, and the inter-vehicle distance between the host vehicle V1 and the preceding vehicle V2 may be adjusted by autonomously controlling the running operation of the host vehicle V1 so that the host vehicle V1 runs along the third trajectory T3. Here, the third target inter-vehicle distance D3 when the host vehicle V1 changes lanes from the host lane L1 to the adjacent lane L2 is an inter-vehicle distance at which a stopping position at which the host vehicle V1 can enter the adjacent lane L2 can be set, and can be set to an appropriate inter-vehicle distance that is shorter than the first target inter-vehicle distance D1 and longer than the second target inter-vehicle distance D2. In addition, when an unsuitable stopping area R2 is set, the vehicle distance can be set to an appropriate distance that allows the host vehicle V1 to set a stopping position that is not included in the unsuitable stopping area R2, and is shorter than the first target vehicle distance D1 and longer than the second target vehicle distance D2.

In this way, for example, by driving the host vehicle V1 along the third trajectory T3 shown in FIG. 6C from the first position P1 shown by the solid line to the third position P3 shown by the dashed line, the host vehicle V1 enters the adjacent lane L2 and there is no risk of interfering with the travel of the following vehicle Vf traveling in the host lane L1. In other words, the vehicle distance between the host vehicle V1 and the preceding vehicle V2 can be shortened by an amount necessary to not interfere with the travel of the following vehicle Vf traveling in the host lane L1, without approaching the preceding vehicle V2 to the shortest possible distance. In addition, in order to maintain the vehicle distance and avoid contact with the preceding vehicle V2, after the host vehicle V1 has traveled to the third position P3, the vehicle distance between the host vehicle V1 and the preceding vehicle V2 may be adjusted so that the vehicle distance is not shorter than the third target vehicle distance D3.

[Target Inter-Vehicle Distance Setting Process]
Next, the process of setting the target inter-vehicle distance in this embodiment will be described with reference to Figures 7A to 7B, 8 and 9. Figures 7A to 7B, 8 and 9 are flowcharts showing the process of adjusting the inter-vehicle distance in the processor 10 in this embodiment. Note that the autonomous control process described below is executed at predetermined time intervals by the driving assistance device 100 in this embodiment.

Figure 7A is an example of a subroutine of step S7 shown in Figure 2. When setting the target inter-vehicle distance between the host vehicle V1 and the preceding vehicle V2 in step S7, the processor 10 of this embodiment uses the route calculation unit 160 to perform processing, for example, according to the procedure shown in Figure 7A.

In step S701, the detection device 1, the environment recognition device 5, and the object recognition device 6 are used to detect a preceding vehicle V2 traveling in the own lane L1 or the adjacent lane L2. If the preceding vehicle V2 is not detected, the process proceeds to step S711. On the other hand, if the preceding vehicle V2 is detected, the process proceeds to step S702.

In step S702, it is determined whether the host vehicle V1 will stop at a position behind the stopped preceding vehicle V2. If the host vehicle V1 will stop at a position in front of the preceding vehicle V2, the process proceeds to step S711. On the other hand, if the host vehicle V1 will stop at a position behind the stopped preceding vehicle V2, the process proceeds to step S703.

In step S703, the target inter-vehicle distance between the host vehicle V1 and the preceding vehicle V2 is set to a first target inter-vehicle distance D1, and a first position P1 is set. In the following step S704, a first trajectory T1 for traveling to the first position P1 is generated.

In step S705, when the host vehicle V1 is viewed in a plan view, it is determined whether or not at least a portion of the host vehicle V1 is included in the unsuitable stopping area R2 at the first position P1. This determination is made using the detection device 1, the environment recognition device 5, and the object recognition device 6. If it is determined that a portion or all of the host vehicle V1 is not included in the unsuitable stopping area R2, the process proceeds to step S8 in FIG. 2, where a driving plan is created for traveling along the first trajectory T1. On the other hand, if it is determined that at least a portion of the host vehicle V1 is included in the unsuitable stopping area R2 at the first position P1, the process proceeds to step S706.

In step S706, the target inter-vehicle distance between the host vehicle V1 and the preceding vehicle V2 is set to a second target inter-vehicle distance D2, and a second position P2 is set. In the following step S707, a second trajectory T2 for traveling to the second position P2 is generated. After the second trajectory T2 is generated, the process proceeds to step S8 in FIG. 2, where a driving plan is created.

If the process proceeds from step S701 or step S702 to step S711, a driving route that satisfies predetermined conditions is calculated, and the process proceeds to step S8 in FIG. 2 to create a driving plan.

Figure 7B is an example of a subroutine of step S8 shown in Figure 2. When the processor 10 of this embodiment generates the second trajectory T2 in step S707, the processor 10 performs processing, for example, according to the procedure shown in Figure 7B, using the driving behavior control unit 170.

In step S801, a driving plan for traveling along the second trajectory T2 is created. In the following step S802, when the vehicle V1 is viewed in a plan view, it is determined whether or not at least a part of the vehicle V1 is included in the unsuitable stopping area R2 at the second position P2. The detection device 1, the environment recognition device 5, and the object recognition device 6 are used for this determination. If it is determined that at least a part of the vehicle V1 is included in the unsuitable stopping area R2 at the second position P2, the process proceeds to step S9 in FIG. 2, where the vehicle V1 travels along the second trajectory T2 and stops at the second position P2 according to the driving plan created in step S801. On the other hand, if it is determined that a part or all of the vehicle V1 is not included in the unsuitable stopping area R2 at the second position P2, the process proceeds to step S803.

In step S803, the host vehicle V1 is caused to travel along the second trajectory T2. Then, in the following step S804, it is determined whether or not at least a portion of the host vehicle V1 is included in the unsuitable stopping area R2. If it is determined that at least a portion of the host vehicle V1 is included in the unsuitable stopping area R2, the process returns to step S803. Steps S803 and S804 are repeated while the host vehicle V1 travels along the second trajectory T2 until it is determined in step S804 that a portion or all of the host vehicle V1 is not included in the unsuitable stopping area R2.

If it is determined in step S804 that the host vehicle V1 is not within the unsuitable stopping area R2, the process proceeds to step S805, where a driving plan is created to stop the host vehicle V1 when the host vehicle V1 is no longer within the unsuitable stopping area R2. The process then proceeds to step S9, where the host vehicle V1 stops.

Figure 8 is another example of the subroutine of step S7 shown in Figure 2. The subroutine shown in Figure 8 is the subroutine shown in Figure 7A with steps S708 to S710 added after step S707. When setting the target inter-vehicle distance between the host vehicle V1 and the preceding vehicle V2 in step S7, the processor 10 of this embodiment may use the route calculation unit 160 to perform processing, for example, according to the procedure shown in Figure 8.

In step S701, the detection device 1, the environment recognition device 5, and the object recognition device 6 are used to detect a preceding vehicle V2 traveling in the own lane L1 or the adjacent lane L2. If the preceding vehicle V2 is not detected, the process proceeds to step S711. On the other hand, if the preceding vehicle V2 is detected, the process proceeds to step S702.

In step S702, it is determined whether the host vehicle V1 will stop at a position behind the stopped preceding vehicle V2. If it is determined that the host vehicle V1 will stop at a position in front of the preceding vehicle V2, the process proceeds to step S711. On the other hand, if it is determined that the host vehicle V1 will stop at a position in front of the preceding vehicle V2, the process proceeds to step S703.

In step S703, the target inter-vehicle distance between the host vehicle V1 and the preceding vehicle V2 is set to a first target inter-vehicle distance D1, and a first position P1 is set. In the following step S704, a first trajectory T1 for traveling to the first position P1 is generated.

In step S705, when the host vehicle V1 is viewed in a plan view, it is determined whether or not a part of the host vehicle V1 is included in the unsuitable stopping area R2 at the first position P1. If it is determined that the host vehicle V1 is not included in the unsuitable stopping area R2, the process proceeds to step S8 in FIG. 2, where a driving plan is created for traveling along the first trajectory T1. On the other hand, if it is determined that a part of the host vehicle V1 is included in the unsuitable stopping area R2 at the first position P1, the process proceeds to step S706.

In step S706, the target inter-vehicle distance between the host vehicle V1 and the preceding vehicle V2 is set to a second target inter-vehicle distance D2, and a second position P2 is set. In the following step S707, a second trajectory T2 for traveling to the second position P2 is generated.

After generating the second trajectory T2 in step S707, in step S708, it is determined whether or not at least a portion of the host vehicle V1 is included in the unsuitable stopping area R2 at the second position P2. If it is determined that a portion or all of the host vehicle V1 is included in the unsuitable stopping area R2 at the second position P2, the process proceeds to step S8 in FIG. 2, where a driving plan is created for traveling along the second trajectory T2. On the other hand, if it is determined that at least a portion of the host vehicle V1 is not included in the unsuitable stopping area R2 at the second position P2, the process proceeds to step S709.

In step S709, the target inter-vehicle distance between the host vehicle V1 and the preceding vehicle V2 is set to a third target inter-vehicle distance D3, and a third position P3 is set. In the following step S710, a third trajectory T3 for traveling to the third position P3 is generated. Then, the process proceeds to step S8 in FIG. 2, and a driving plan for traveling along the third trajectory T3 is created. Note that when the process proceeds from step S701 or step S702 to step S711, the process is the same as the flowchart in FIG. 7A.

Figure 9 is yet another example of the subroutine of step S7 shown in Figure 2. The subroutine shown in Figure 9 executes steps S705a to S705c instead of step S705 in the subroutine shown in Figure 7A. When setting the target inter-vehicle distance between the host vehicle V1 and the preceding vehicle V2 in step S7, the processor 10 of this embodiment may use the route calculation unit 160 to perform processing, for example, according to the procedure shown in Figure 9.

In step S701, the detection device 1, the environment recognition device 5, and the object recognition device 6 are used to detect a preceding vehicle V2 traveling in the own lane L1 or the adjacent lane L2. If the preceding vehicle V2 is not detected, the process proceeds to step S711. On the other hand, if the preceding vehicle V2 is detected, the process proceeds to step S702.

In step S702, it is determined whether the host vehicle V1 will stop at a position behind the stopped preceding vehicle V2. If it is determined that the host vehicle V1 will stop at a position in front of the preceding vehicle V2, the process proceeds to step S711. On the other hand, if it is determined that the host vehicle V1 will stop at a position in front of the preceding vehicle V2, the process proceeds to step S703.

In step S703, the target inter-vehicle distance between the host vehicle V1 and the preceding vehicle V2 is set to a first target inter-vehicle distance D1, and a first position P1 is set. In the following step S704, a first trajectory T1 for traveling to the first position P1 is generated.

After generating the first trajectory T1 in step S704, in step S705a, it is determined whether or not the lane change of the host vehicle V1 has been completed at the first position P1. If it is determined that the lane change has not been completed, the process proceeds to step S706. On the other hand, if it is determined that the lane change has been completed, the process proceeds to step S705b.

In step S705b, the detection device 1 is used to detect a following vehicle Vf following the host vehicle V1. If a following vehicle Vf following the host vehicle V1 is not detected, the process proceeds to step S8 in FIG. 2, where a driving plan for traveling along the first trajectory is created. On the other hand, if a following vehicle Vf following the host vehicle V1 is detected, the process proceeds to step S705c.

In step S705c, when a following vehicle Vf following the host vehicle V1 stops, it is determined whether or not at least a portion of the following vehicle Vf is included in the stopping inappropriate area R2. If it is determined that a portion or all of the following vehicle Vf is not included in the stopping inappropriate area R2, the process proceeds to step S8 in FIG. 2, where a driving plan for traveling along the first trajectory is created. On the other hand, if it is determined that at least a portion of the following vehicle Vf is included in the stopping inappropriate area R2, the process proceeds to step S706.

When the process proceeds from step S705a or step S705c to step S706, the target inter-vehicle distance between the host vehicle V1 and the preceding vehicle V2 is set to a second target inter-vehicle distance D2, and a second position P2 is set. In the following step S707, a second trajectory T2 for traveling to the second position P2 is generated. Then, the process proceeds to step S8 in FIG. 2, and a driving plan for traveling along the second trajectory T2 is created.

If the process proceeds from step S701 or step S702 to step S711, a driving route that satisfies predetermined conditions is calculated, and the process proceeds to step S8 in FIG. 2 to create a driving plan.

[Embodiments of the invention]
As described above, according to the vehicle driving assistance method and assistance device of this embodiment, a preceding vehicle V2 traveling in front of the host vehicle V1 in the host vehicle V1's lane L1 or in the lane adjacent to the host vehicle V1 is detected, and when the detected preceding vehicle V2 stops and the host vehicle V1 stops behind the preceding vehicle V2, a target inter-vehicle distance between the host vehicle V1 and the preceding vehicle V2 is set to a first target inter-vehicle distance D1, and based on the situation of the host vehicle V1 when the host vehicle V1 stops behind the preceding vehicle V2 at the first target inter-vehicle distance D1 or the situation of another vehicle or pedestrian, it is determined whether or not it is necessary to set the target inter-vehicle distance to a second target inter-vehicle distance D2 that is smaller than the first target inter-vehicle distance, and when it is determined that the second target inter-vehicle distance D2 needs to be set, the target inter-vehicle distance is set to the second target inter-vehicle distance D2, and the driving of the host vehicle is controlled so that the inter-vehicle distance between the host vehicle V1 and the preceding vehicle V2 becomes the second target inter-vehicle distance D2, thereby adjusting the inter-vehicle distance. This allows the vehicle V1 to travel to a position where it does not interfere with the traffic of other vehicles, particularly the following vehicle Vf traveling in the vehicle's lane L1, thereby avoiding becoming an obstacle to the traffic of other vehicles, such as the following vehicle Vf.

In addition, according to the vehicle driving assistance method and assistance device of this embodiment, when the host vehicle V1 is unable to complete a lane change from the host lane L1 to the adjacent lane L2, the target inter-vehicle distance is set to the second target inter-vehicle distance D2. This prevents the host vehicle V1 from stopping across the host lane L1 and the adjacent lane L2, thereby avoiding obstruction to the traffic of other vehicles such as the following vehicle Vf.

In addition, according to the vehicle driving assistance method and assistance device of this embodiment, in the driveable area R1 in which the host vehicle V1 can drive, an unsuitable stopping area R2 is set in which the host vehicle V1 will impede traffic for other vehicles or pedestrians if the host vehicle V1 stops, and it is determined whether at least a portion of the host vehicle V1 is included in the unsuitable stopping area R2. If it is determined that at least a portion of the host vehicle V1 is included in the unsuitable stopping area R2, the target inter-vehicle distance is set to the second target inter-vehicle distance D2. As a result, the host vehicle V1 drives to a position that is not included in the unsuitable stopping area R2, and therefore it is possible to avoid becoming an obstacle to traffic for other vehicles such as the following vehicle Vf.

In addition, according to the vehicle driving assistance method and assistance device of this embodiment, when the host vehicle V1 changes lanes from the host vehicle lane L1 to the adjacent lane L2, the host vehicle lane L1 is set as an unsuitable stopping area R2. This makes it possible to prevent the host vehicle V1 from stopping across the host vehicle lane L1 and the adjacent lane L2, and to avoid interfering with the traffic of other vehicles such as the following vehicle Vf.

In addition, according to the vehicle driving support method and support device of this embodiment, when the host lane L1 branches into a main line and a branch line Lb ahead, the main line is set as an unsuitable stopping area R2 when the host vehicle V1 is traveling on the branch line Lb, and when the host vehicle V1 is traveling on the main line, the branch line Lb and a position on the main line where a vehicle entering the branch line Lb from the main line is traveling are set as unsuitable stopping areas R2. As a result, when the host lane L1 branches into the main line and the branch line Lb ahead, the host vehicle V1 stops at a position that does not interfere with the traveling of the following vehicle Vf traveling on the host lane L1, and therefore can avoid becoming an obstacle to the traffic of other vehicles such as the following vehicle Vf.

In addition, according to the vehicle driving support method and support device of this embodiment, at least one of the crosswalk CW, intersection C, and no-stopping area NS that exist within the drivable area R1 is set as an unsuitable stopping area R2. As a result, when the vehicle V1 is traveling in an urban area, the vehicle V1 stops at a position that does not impede the traffic of other vehicles, such as pedestrians or emergency vehicles, and thus can avoid becoming an obstacle to the traffic of other vehicles.

In addition, according to the vehicle driving support method and support device of this embodiment, when a facility F exists along the road on which the host vehicle V1 is traveling, in a situation where another vehicle is entering the facility F, the area where the other vehicle will travel to enter the facility F is set as an unsuitable stopping area R2, and in a situation where the host vehicle V1 is entering the facility F, the sidewalk SW existing between the road and the facility F is set as an unsuitable stopping area R2. As a result, the host vehicle V1 travels to a position where it does not interfere with the travel of an oncoming vehicle Vo entering the facility F1 along the road, so that it is possible to avoid becoming an obstacle to the traffic of the oncoming vehicle Vo. In addition, when the host vehicle V1 enters the facility F2 along the road, it is possible to stop the vehicle at a position where it does not become an obstacle to pedestrians on the sidewalk SW.

In addition, according to the vehicle driving support method and support device of this embodiment, the unsuitable stopping area R2 is set using high-resolution map information or the detection results of the detection device 1. This makes it possible to accurately set the unsuitable stopping area R2.

In addition, according to the vehicle driving support method and support device of this embodiment, when a following vehicle Vf following the host vehicle V1 is detected, it is determined whether or not at least a part of the following vehicle Vf is included in the unsuitable stopping area R2, and when it is determined that a part or all of the following vehicle Vf following the host vehicle V1 is included in the unsuitable stopping area R2, the target inter-vehicle distance is set to the second target inter-vehicle distance D2 so that the following vehicle Vf is no longer included in the unsuitable stopping area R2. This makes it possible to create space for the following vehicle Vf following the host vehicle V1 to enter the adjacent lane L2, and allows the following vehicle Vf to stop in a position that does not interfere with the driving of other vehicles following the following vehicle Vf.

In addition, according to the vehicle driving support method and support device of this embodiment, it is assumed that there is a following vehicle Vf following the host vehicle V1, and it is determined whether or not at least a part of the assumed following vehicle Vf is included in the stopping unsuitable area R2. If it is determined that a part or all of the assumed following vehicle Vf is included in the stopping unsuitable area R2, the target inter-vehicle distance is set to the second target inter-vehicle distance D2 so that the assumed following vehicle Vf is not included in the stopping unsuitable area R2. As a result, before the following vehicle Vf following the host vehicle V1 is detected, a space can be created for the following vehicle Vf to enter the adjacent lane L2, so that when the following vehicle Vf following the host vehicle V1 is actually detected, the detected following vehicle Vf can be stopped in a position that does not interfere with the driving of other vehicles following the following vehicle Vf.

In addition, according to the vehicle driving assistance method and assistance device of this embodiment, when determining whether the host vehicle V1 will stop behind the leading vehicle V2, the stopping position where the host vehicle V1 will stop is calculated, and the stopping position is used to determine whether it is necessary to set the target inter-vehicle distance to a second target inter-vehicle distance D2 that is smaller than the first target inter-vehicle distance D1. This makes it possible to accurately determine whether it is necessary to set the second target inter-vehicle distance D2 using the detected stopping position.

In addition, according to the vehicle driving support method and support device of this embodiment, the host vehicle V1 is stopped at the first position P1 where the vehicle distance is the first target vehicle distance D1, and then the host vehicle V1 is slowed down from the first position P1 to the second position P2 where the vehicle distance is the second target vehicle distance D2, and if it is determined during the slowing down that it is no longer necessary to shorten the vehicle distance, the host vehicle V1 is stopped. As a result, the host vehicle V1 approaches the leading vehicle V2 while reducing its vehicle speed, so that contact with the leading vehicle V2 can be further avoided. In addition, it is possible to avoid a situation in which the host vehicle V1 unnecessarily approaches the leading vehicle V2. Furthermore, if the host vehicle V1 approaches the leading vehicle V2 too close, the leading vehicle V2 will obstruct the imaging area of the detection device 1, increasing the blind spot in the detection area of the detection device 1, but this can be suppressed.

In addition, according to the vehicle driving support method and support device of this embodiment, after the host vehicle V1 reaches a position at a predetermined distance from the first position P1 where the vehicle distance is the first target vehicle distance D1, the host vehicle V1 is slowed down from the position at the predetermined distance from the first position P1 to the second position P2 where the vehicle distance is the second target vehicle distance D2, and if it is determined during the slowing down that it is no longer necessary to shorten the vehicle distance, the host vehicle V1 is stopped. As a result, the host vehicle V1 approaches the leading vehicle V2 at a reduced speed, so that contact with the leading vehicle V2 can be further avoided. In addition, it is possible to avoid a situation in which the host vehicle V1 approaches the leading vehicle V2 unnecessarily. Furthermore, it is possible to suppress an increase in the blind spot of the detection area of the detection device 1 caused by the leading vehicle V2, which occurs when the host vehicle V1 approaches the leading vehicle V2.

In addition, according to the vehicle driving support method and support device of this embodiment, when the second target inter-vehicle distance D2 is the shortest distance that can be set as the target inter-vehicle distance, a third target inter-vehicle distance D3 is set that is shorter than the first target inter-vehicle distance D1 and longer than the second target inter-vehicle distance D2, and the driving of the host vehicle V1 is controlled so that the inter-vehicle distance becomes the third target inter-vehicle distance D3, and the inter-vehicle distance is adjusted. As a result, the host vehicle V1 approaches the preceding vehicle V2 while reducing its vehicle speed, so that contact with the preceding vehicle V2 can be further avoided. In addition, it is possible to avoid a situation in which the host vehicle V1 unnecessarily approaches the preceding vehicle V2. Furthermore, it is possible to suppress an increase in the blind spot of the detection area of the detection device 1 caused by the preceding vehicle V2, which occurs when the host vehicle V1 approaches the preceding vehicle V2.

In addition, according to the vehicle driving support method and support device of this embodiment, the vehicle distance is adjusted so that the vehicle distance is not shorter than the third target vehicle distance D3. This makes it possible to avoid a situation in which the host vehicle V1 unnecessarily approaches the leading vehicle V2.

REFERENCE SIGNS LIST 1000 Driving support system 1 Detection device 2 Navigation device 3 Map information 4 Vehicle information detection device 5 Environment recognition device 6 Object recognition device 100 Driving support device 10 Processor 11 CPU
12...ROM
13...RAM
110: Output device 111: Communication device 120: Destination setting unit 130: Route planning unit 140: Driving planning unit 150: Driveable area calculation unit 160: Route calculation unit 170: Driving behavior control unit 200: Vehicle control device 210: Drive mechanism 211: Communication device B: Branch point C: Intersection CW, CW1, CW2: Crosswalk D1: First target inter-vehicle distance D2: Second target inter-vehicle distance D3: Third target inter-vehicle distance E1: End L1: Own lane L2: Adjacent lane Lb: Branch line Lo: Oncoming lane NS: Stopping prohibition portion P1, P1a, P1b: First position P2, P2a, P2b: Second position P3: Third position Pc: Current position Pf1, Pf2, Pf3: Position (following vehicle)
Po1, Po2...position (oncoming vehicle)
Px: Stop position Q1, Q2: Position (preceding vehicle)
R1: Drivable area R2, R2a, R2b, R2c, R2d: Unsuitable stopping area SW: Sidewalk T1: First trajectory T2, T2a, T2b: Second trajectory T3: Third trajectory Tf: Trajectory (following vehicle)
To...Trajectory (oncoming vehicle)
Tx...Trajectory (Comparative Example)
V1, V1a, V1b... own vehicles V2, V2a, V2b... preceding vehicles V3, V4, V5... other vehicles Vf... following vehicle Vo... oncoming vehicle

Claims (7)

A vehicle driving support method executed by a processor, comprising:
The processor,
Detecting a preceding vehicle traveling ahead of the host vehicle in a lane in which the host vehicle is traveling or in a lane adjacent to the host vehicle;
When the detected preceding vehicle stops and the host vehicle stops behind the preceding vehicle, a target inter-vehicle distance between the host vehicle and the preceding vehicle is set to a first target inter-vehicle distance;
determining whether or not it is necessary to set the target inter-vehicle distance to a second target inter-vehicle distance that is smaller than the first target inter-vehicle distance, based on a state of the host vehicle when the host vehicle stops behind the preceding vehicle at the first target inter-vehicle distance or a state of another vehicle or a pedestrian;
When it is determined that the target inter-vehicle distance needs to be set to the second target inter-vehicle distance, the target inter-vehicle distance is set to the second target inter-vehicle distance;
controlling travel of the host vehicle so that a vehicle-to-vehicle distance between the host vehicle and the preceding vehicle becomes the second target vehicle-to-vehicle distance, and adjusting the vehicle-to-vehicle distance ;
A vehicle driving support method , comprising: when it is determined that the host vehicle cannot complete a lane change from the host vehicle lane to the adjacent lane, setting the target inter-vehicle distance to the second target inter-vehicle distance . The processor,
When determining whether or not the host vehicle will stop behind the preceding vehicle, a stop position where the host vehicle will stop is calculated;
The vehicle driving support method according to claim 1 , further comprising: determining whether or not it is necessary to set the second target inter-vehicle distance, which is smaller than the first target inter-vehicle distance, using the calculated vehicle stop position. The processor,
After stopping the host vehicle at a first position where the inter-vehicle distance becomes the first target inter-vehicle distance, the host vehicle is caused to move slowly from the first position to a second position where the inter-vehicle distance becomes the second target inter-vehicle distance;
3. The vehicle driving support method according to claim 1 , further comprising the step of: stopping the host vehicle when it is determined that it is no longer necessary to reduce the inter-vehicle distance during slow driving. The processor,
after the host vehicle has reached a position that is a predetermined distance from a first position where the vehicle distance becomes the first target vehicle distance, the host vehicle is caused to move slowly from the position that is the predetermined distance from the first position to a second position where the vehicle distance becomes the second target vehicle distance;
3. The vehicle driving support method according to claim 1 , further comprising the step of: stopping the host vehicle when it is determined that it is no longer necessary to reduce the inter-vehicle distance during slow driving. The processor,
3. The vehicle driving assistance method according to claim 1 or 2, further comprising the steps of: when the second target inter-vehicle distance is the shortest distance that can be set as the target inter-vehicle distance, setting a third target inter-vehicle distance that is shorter than the first target inter-vehicle distance and longer than the second target inter-vehicle distance; controlling the driving of the host vehicle so that the inter-vehicle distance becomes the third target inter-vehicle distance; and adjusting the inter-vehicle distance. The processor,
The vehicle driving support method according to claim 5 , further comprising controlling driving of the host vehicle to adjust the inter-vehicle distance so that the inter-vehicle distance does not become shorter than the third target inter-vehicle distance. Detecting a preceding vehicle traveling ahead of the host vehicle in a lane in which the host vehicle is traveling or in a lane adjacent to the host vehicle;
When the detected preceding vehicle stops and the host vehicle stops behind the preceding vehicle, a target inter-vehicle distance between the host vehicle and the preceding vehicle is set to a first target inter-vehicle distance;
determining whether or not it is necessary to set the target inter-vehicle distance to a second target inter-vehicle distance that is smaller than the first target inter-vehicle distance, based on a state of the host vehicle when the host vehicle stops behind the preceding vehicle at the first target inter-vehicle distance or a state of another vehicle or a pedestrian;
When it is determined that it is necessary to set the second target inter-vehicle distance, the target inter-vehicle distance is set to the second target inter-vehicle distance;
A vehicle driving support device including a processor for controlling driving of the host vehicle and adjusting the inter-vehicle distance so that the inter-vehicle distance between the host vehicle and the preceding vehicle becomes the second target inter-vehicle distance,
A vehicle driving assistance device, wherein the processor sets the target inter-vehicle distance to the second target inter-vehicle distance when it determines that the vehicle cannot complete a lane change from the vehicle's own lane to the adjacent lane .

Images