JP7515782B2 - Vehicle Control Systems - Google Patents

Description

The present invention relates to a vehicle control system, and in particular to a vehicle control system that uses a sensor to detect the position of a road edge and pulls the vehicle over to the road edge to stop it.

Conventionally, vehicle control systems have been developed that can safely stop a vehicle by automatically detecting an abnormality in the driver or by having the passenger press an emergency button when the driver is unable to drive safely. For example, Patent Document 1 discloses an emergency evacuation system that determines a target stopping position, such as within an intersection or on the roadside, when the driver's level of consciousness decreases, and stops the vehicle at the target stopping position. In the conventional technology described in Patent Document 1, a millimeter wave sensor detects obstacles such as guardrails, soundproof walls, and curbs, and a front camera sensor detects road markings such as white lines, and these are used to determine the target stopping position for the vehicle.

JP 2009-163434 A

In conventional technology such as the system of Patent Document 1, various sensors used to detect obstacles and road markings each have advantages and disadvantages. For example, when a monocular camera is used as a forward camera sensor, the angle from the vehicle to the object can be accurately detected, but the distance to the object has a relatively large error. On the other hand, a millimeter wave sensor can relatively accurately detect the distance from the vehicle to the object, but errors may occur in the angle from the vehicle to the object due to radio wave diffraction, etc. Therefore, in order to detect the position of the road edge so that the vehicle can pull over to the road edge and stop in an emergency, it is necessary to improve the reliability of road edge detection using a sensor.

The present invention has been made to solve the problems with the conventional technology described above, and aims to provide a vehicle control system that can obtain a reliable roadside position when pulling the vehicle over to the roadside and stopping it.

In order to achieve the above-mentioned object, the vehicle control system of the present invention is a vehicle control system that detects the position of a roadside edge using a sensor and pulls the vehicle over to the roadside and stops the vehicle, and has a camera that photographs the area in front of the vehicle, a radar that scans the area around the vehicle to measure the position of a measured object, and a controller configured to control the steering and braking devices of the vehicle to pull the vehicle over to the roadside and stop the vehicle based on the image photographed by the camera and the position information of the measured object measured by the radar, wherein the controller is configured to acquire coordinates of multiple positions on the roadside based on the image photographed by the camera, acquire coordinates of multiple positions on the roadside based on the position information of the measured object measured by the radar, combine the coordinates of the multiple positions on the roadside acquired based on the image photographed by the camera and the coordinates of the multiple positions on the roadside acquired based on the position information of the measured object measured by the radar to generate a sequence of coordinate points of the multiple positions on the roadside, control the steering device so that the vehicle approaches the sequence of coordinate points, and control the braking device so that the vehicle stops after it approaches the sequence of coordinate points.
In the present invention thus configured, the controller moves the vehicle closer to the coordinate point sequence that combines the coordinates of the road edge from the camera and the radar, so that the vehicle can be moved closer to the road edge without coming into contact with the coordinates that protrude further toward the road. Therefore, even if the coordinates of the road edge from the camera and the radar each contain an error, the vehicle will not be moved too close to the road edge. In other words, a highly reliable road edge position can be obtained.

The vehicle control system of the present invention can obtain a highly reliable roadside position when pulling the vehicle over to the roadside and stopping it.

1 is a schematic configuration diagram of a vehicle to which a vehicle control system according to an embodiment of the present invention is applied. 1 is a block diagram showing an electrical configuration of a vehicle control system according to an embodiment of the present invention. 4 is a flowchart of an automatic vehicle stop process executed by the vehicle control system according to the embodiment of the present invention. 1 is a plan view showing a sequence of road edge coordinate points detected when the vehicle control system according to the embodiment of the present invention executes an automatic vehicle stop process. FIG. 1 is a plan view showing a virtual line and the movement of a vehicle when an automatic stop process is executed by a vehicle control system according to an embodiment of the present invention. FIG. 10 is a time chart showing a change in the lateral movement speed of a virtual line when the vehicle control system according to the embodiment of the present invention executes an automatic stopping process.

The vehicle control system according to an embodiment of the present invention will be described below with reference to the attached drawings.

<System Configuration>
First, the overall configuration of a vehicle to which a vehicle control system according to an embodiment of the present invention is applied will be described with reference to Figures 1 and 2. Figure 1 is a schematic diagram of a vehicle to which a vehicle control system according to an embodiment of the present invention is applied. Figure 2 is a block diagram showing the electrical configuration of the vehicle control system according to the embodiment of the present invention.

As shown in FIG. 1, reference numeral 1 denotes a vehicle to which the vehicle control system according to this embodiment is applied. The vehicle 1 has an engine 31 that generates driving force, a brake 32 that brakes the vehicle 1, and an electric power steering 33. The vehicle 1 is also provided with a camera 21 that captures images of the area ahead of the vehicle 1, and a radar 22 that detects obstacles around the vehicle 1.

2, the vehicle 1 is provided with a vehicle speed sensor 23 that detects the vehicle speed, an acceleration sensor 24 that detects the acceleration in the traveling direction of the vehicle 1, a yaw rate sensor 25 that detects the yaw rate of the vehicle 1, a steering angle sensor 26 that detects the steering angle of the vehicle 1, an accelerator sensor 27 that detects the operation of the accelerator pedal (e.g., the accelerator opening), a brake sensor 28 that detects the operation of the brake pedal (e.g., the amount of depression of the brake pedal), a positioning system 29 that detects the position of the vehicle 1, and a navigation system 30. Image data captured by the camera 21, position information of obstacles detected by the radar 22, position information acquired by the positioning system 29, information on the position of emergency parking lanes acquired from the navigation system 30, and detection data detected by each sensor are output to the controller 10.

The camera 21 captures the surroundings of the vehicle 1 and outputs image data. Based on the image data received from the camera 21, the controller 10 identifies objects (e.g., road dividing lines (e.g., white and yellow lines including lane boundaries, outer roadway lines, and outermost vehicle lane lines), road edges (boundaries between the road and other objects, e.g., boundaries between pavement and soil, guard rails, curbs, etc.), other vehicles, pedestrians, traffic lights, signs, stop lines, intersections, obstacles, etc.).

The radar 22 measures the position and speed of objects (particularly road edges (boundaries between roads and other objects, such as boundaries between pavement and soil, guard rails, curbs, etc.), other vehicles, pedestrians, obstacles, etc.). For example, a millimeter wave radar can be used as the radar 22. The radar 22 transmits radio waves to the vicinity of the vehicle 1 and receives reflected waves that are generated when the transmitted waves are reflected by objects. Then, based on the transmitted waves and received waves, the radar 22 measures the direction and distance from the vehicle 1 to the object, and the relative speed between the vehicle 1 and the object. Note that instead of such a radar 22, a laser radar, ultrasonic sensor, etc. may be used to measure the distance to the object and the relative speed.

As shown in FIG. 2, the controller 10 receives inputs of image data captured by the camera 21, position information of obstacles detected by the radar 22, position information acquired by the positioning system 29, information on the positions of emergency parking lanes acquired from the navigation system 30, and detection data detected by the sensors 23 to 28.

The controller 10 is composed of a computer that includes one or more processors 10a (typically a CPU), various programs that are interpreted and executed on the processor (including basic control programs such as an OS, and application programs that are started on the OS and realize specific functions), and memory 10b such as a ROM or RAM for storing programs and various data.

Specifically, the controller 10 mainly outputs control signals to the engine 31, the brake 32, and the electric power steering 33 based on image data captured by the camera 21, position information of obstacles detected by the radar 22, position information acquired by the positioning system 29, information on the position of emergency parking lanes acquired from the navigation system 30, and detection data detected by the sensors 23 to 28, to control these. For example, the controller 10 controls the spark plug, fuel injection valve, throttle valve, etc. of the engine 31 to adjust the ignition timing, fuel injection timing, and fuel injection amount of the engine 31. The controller 10 also controls, for example, the hydraulic pump and valve unit of the brake 32 to generate a braking force in the brake 32. The controller 10 also controls the motor of the electric power steering 33 to change the traveling direction of the vehicle 1.

<Vehicle Control>
Next, the automatic stopping process of the vehicle 1 performed by the vehicle control system will be described with reference to FIG. 3 to FIG.
Fig. 3 is a flowchart of the automatic stop processing executed by the vehicle control system according to the embodiment of the present invention. Fig. 4 is a plan view showing a sequence of road edge coordinate points detected when the vehicle control system according to the embodiment of the present invention executes the automatic stop processing. Fig. 5 is a plan view showing the movement of the virtual line and the vehicle when the vehicle control system according to the embodiment of the present invention executes the automatic stop processing. Fig. 6 is a time chart showing the change in the lateral movement speed of the virtual line when the vehicle control system according to the embodiment of the present invention executes the automatic stop processing.

The automatic stopping process in FIG. 3 is a process for moving vehicle 1 from the lane in which it is traveling to the edge of the road and stopping it when vehicle 1 is traveling in a lane adjacent to the edge of the road at a predetermined vehicle speed (e.g., 20 km/h) or less. For example, if the emergency button on vehicle 1 is pressed while traveling in the passing lane of a highway, or if a driver abnormality is detected by the driver monitoring system, controller 10 changes vehicle 1 to a lane adjacent to the edge of the road using known automatic driving control, and decelerates vehicle 1 to a predetermined vehicle speed while traveling in that lane. After that, the automatic stopping process in FIG. 3 is started and executed by controller 10.

As shown in FIG. 3, when the automatic stopping process is started, in step S11, the controller 10 acquires various information about the vehicle 1, including image data captured by the camera 21 described above, position information of obstacles detected by the radar 22, position information acquired by the positioning system 29, information on the position of emergency parking lanes acquired from the navigation system 30, and information corresponding to the detection data detected by each of the sensors 23 to 28.

Next, in step S12, the controller 10 detects the lane markings of the road on which the vehicle 1 is traveling, based on the image data input from the camera 21 in step S11. In the example shown in Figures 4 and 5, the controller 10 detects the lane markings OL (outer lane markings) and lane markings BL (lane boundary lines).

Next, in step S13, the controller 10 acquires the coordinates of multiple positions on the road edge on the side to which the vehicle 1 is to be pulled over (the left side of the vehicle 1 when the vehicle is traveling on a road with left-hand traffic) based on the image data input from the camera 21 in step S11. For example, the controller 10 detects the edge of the curb that forms the road edge based on the brightness of the image data. Then, the controller 10 acquires the coordinates of multiple positions on the edge in a plane coordinate system with the current position of the vehicle 1 as the reference point. If the camera 21 is a stereo camera, the coordinates of multiple positions on the road edge can be acquired in real time. Also, if the camera 21 is a monocular camera, the coordinates of multiple positions on the road edge can be calculated by the principle of triangulation using the change in the viewpoint position of the camera 21 accompanying the traveling of the vehicle 1. The coordinates of multiple positions on the road edge acquired here are shown in FIG. 4(a). In the example of FIG. 4(a), the coordinates of multiple positions on the road edge E acquired based on the image data of the camera 21 are indicated by black circles.

Next, in step S14, the controller 10 acquires the coordinates of multiple positions on the road edge E on the side to which the vehicle 1 is to be pulled over (the left side of the vehicle 1 if the vehicle is traveling on a road with left-hand traffic) based on the obstacle position information input from the radar 22 in step S11. For example, the controller 10 detects the edge of the curb that forms the road edge based on the intensity of the reflected wave received by the radar 22 and the phase difference with the transmitted wave. Then, the controller 10 acquires the coordinates of multiple positions on the edge in a plane coordinate system with the current position of the vehicle 1 as the reference point. In the example of FIG. 4(a), the coordinates of multiple positions on the road edge E acquired based on the data from the radar 22 are indicated by black squares.

Next, in step S15, the controller 10 combines the coordinates of the multiple positions on the road end E acquired in step S13 based on the image data of the camera 21 with the coordinates of the multiple positions on the road end E acquired in step S14 based on the data from the radar 22 to generate a sequence of coordinate points of the multiple positions on the road end E. The sequence of coordinate points of the multiple positions on the road end E generated here is indicated by hollow triangles in Figure 4 (b).

Next, in step S16, the controller 10 generates a pair of left and right virtual lines extending from the sides of the vehicle 1 toward the front along the lane markings detected in step S12. An example of the pair of left and right virtual lines generated here is shown in Fig. 5(a). In the example of Fig. 5(a), the controller 10 generates a left virtual line IL L (shown by a thick solid line) so as to overlap with a lane marking OL (outer lane marking) on the left side in the traveling direction of the lane in which the vehicle 1 is traveling (i.e., the side closer to the road edge E), and generates a right virtual line IL _R (shown by a dashed line) so as to overlap with a lane marking BL (lane boundary line) on the right side in the traveling direction of the lane in which the vehicle ₁ is traveling (i.e., the side farther from the road edge E).

Next, in step S17, the controller 10 starts controlling the electric power steering 33 so that the vehicle 1 travels along the midpoint between the pair of _{left and right virtual lines. In the example of Fig. 5(a) showing the state in which the pair of left and right virtual lines are generated in step S16, the controller 10 sets the midpoint between the left virtual line IL L} and the right virtual line IL _R as the target travel trajectory TP (indicated by a dashed line). Then, the controller 10 determines the steering assist torque by the electric power steering 33 and controls the motor of the electric power steering 33 so that the vehicle 1 travels along the target travel trajectory TP.

Next, in step S18, the controller 10 moves the left virtual line IL _L in parallel toward the road end E, and then in step S19, moves the left virtual line IL _L to a position closest to the coordinate points that protrude most toward the road side among the sequence of coordinate points of the multiple positions on the road end E generated in step S15, and fixes it at that position.

In the example of FIG. 5, the left virtual line IL _L , which overlaps with the dividing line OL closest to the road edge E as shown in FIG. 5(a), moves toward the road edge E as shown in FIG. 5(b), and is fixed at a position close to the coordinate P that is the most protruding toward the road side among the coordinate point sequence of multiple positions on the road edge E. The "position close to the coordinate P" is a position that is a predetermined distance M away from the coordinate P toward the road side in the width direction of the road shoulder. The predetermined distance M can be determined in consideration of the interval required for a person to pass between the vehicle 1 and the road edge E, and is, for example, M=0.2 m. As the left virtual line IL _L moves, the target driving trajectory TP, which is set at the midpoint of the interval between the left virtual line IL _L and the right virtual line IL _R , also moves toward the road edge E. The moving speed of the target driving trajectory TP at this time is 1/2 the speed of the moving speed profile of the left virtual line IL _L.

FIG. 6 is a time chart showing the change in the lateral moving speed (speed profile) of the virtual line. In FIG. 6, the horizontal axis indicates time, and the vertical axis indicates the lateral moving speed of the virtual line. On the horizontal axis, T0 indicates the start time of the movement of the left virtual line IL _L , T1 indicates the end time of the movement of the left virtual line IL _L and the start time of the movement of the right virtual line IL _R , and T2 indicates the end time of the movement of the right virtual line IL _R. In FIG. 6, the speed profile of the left virtual line IL _L is shown by a curve G11. That is, according to the speed profile G11, the left virtual line IL _L starts moving at time T0, and then moves toward the road edge E while gradually increasing its speed. Thereafter, as the left virtual line IL _L approaches the road edge E, the increase rate of the moving speed decreases, and at time T1, the moving speed becomes maximum, and the left virtual line IL _L reaches a position close to the coordinate P that protrudes most toward the road side among the coordinate point sequence of multiple positions on the road edge E, and is fixed at that position (state of FIG. 5(b)). That is, the moving speed of the left virtual line IL _L becomes 0.

As described above, as the left virtual line IL _L moves, the target traveling path TP, which is set in the middle of the gap between the left virtual line IL _L and the right virtual line IL _R , moves at half the speed of the speed profile of the left virtual line IL _L. That is, in Fig. 6, the speed profile of the target traveling path TP is represented by a curve G31, which is half the speed of the speed profile G11. That is, after starting to move at time T0, the target traveling path TP moves toward the road edge E while gradually increasing its speed. Thereafter, as the left virtual line IL _L approaches the road edge E, the rate of increase in the moving speed decreases, and the moving speed reaches a maximum value at time T1.

After step S19, the process proceeds to step S20, where the controller 10 moves the right virtual line IL _R in parallel toward the road edge E, and then, in step S21, fixes the right virtual line IL _R at a position spaced apart from the left virtual line IL _L by the vehicle width of the vehicle 1 (i.e., the position of the side of the vehicle 1 opposite the road edge E). In the example of FIG. 5, the right virtual line IL R, which overlaps with the dividing line BL adjacent to the side opposite the road edge E of the vehicle 1 as shown in FIG. 5(a) and _FIG . 5(b), moves toward the road edge E as shown in FIG. 5(c), and is fixed at the position of the right side of the vehicle 1. As the right virtual line IL _R moves, the target running path TP, which is set at the middle of the interval between the left virtual line IL _L and the right virtual line IL _R , also moves toward the road edge E. The moving speed of the target running path TP at this time is half the speed of the speed profile of the right virtual line IL _R , similar to the movement of the left virtual line IL _L. The position at which the right virtual line IL _R is fixed is a position away from the left virtual line IL _L by the vehicle width of the vehicle 1, so that the vehicle width direction position of the vehicle 1 is fixed at a position sandwiched between the left virtual line IL _L and the right virtual line IL _R , as shown in FIG. 5( c).

6, the speed profile of the right virtual line IL _R is shown by a curve G21. That is, according to the speed profile G21, at time T1, the right virtual line IL _R starts moving at the same speed as the moving speed at which the left virtual line IL _L reached a position close to the coordinate P. Thereafter, the right virtual line IL R moves toward the road edge E while gradually decreasing the speed, and at time T2, the moving speed becomes 0, and the right virtual line IL _R reaches a position separated from the left virtual line IL _L by the vehicle width of the vehicle 1 (i.e., a position on the side of the vehicle 1 opposite the road edge E) and is fixed at that position (the state in FIG. 5(c)).

As described above, with the movement of the right virtual line IL _R , the target traveling locus TP, which is set in the middle of the interval between the left virtual line IL _L and the right virtual line IL _R , moves at a speed half that of the speed profile of the right virtual line IL _R. That is, in FIG. 6, the speed profile of the target traveling locus TP is represented by a curve G31, which is half the speed of the speed profile G21. That is, the target traveling locus TP moves toward the road edge E while gradually decreasing the speed from time T1. Thereafter, as the right virtual line IL _R approaches the side of the vehicle 1 opposite to the road edge E, the rate of decrease in the moving speed decreases, and the moving speed becomes 0 at time T2. In addition, since the moving speed when the left virtual line IL _L reaches a position close to the coordinate P at time T1 is the same as the moving speed when the right virtual line IL _R starts moving at time T1, the moving speed of the target traveling locus TP smoothly continues before and after time T1. In other words, the vehicle 1's widthwise movement speed is almost constant before and after time T1 and does not change discontinuously, thereby preventing the occupants from feeling uneasy or uncomfortable due to unstable behavior of the vehicle 1.

After step S21, the process proceeds to step S22, where the controller 10 stops the vehicle 1. For example, the controller 10 controls the engine 31 and the brakes 32 so that a predetermined deceleration (e.g., deceleration of 0.2 G or less) occurs until the vehicle speed becomes 0. After the vehicle 1 stops, the controller 10 ends the automatic stop process.

<Modification>
Next, a further modification of the embodiment of the present invention will be described.
In the above-described embodiment, the vehicle 1 equipped with the vehicle control system is described as being equipped with an engine 31 as a power source that generates driving force. However, instead of or together with the engine 31, the vehicle 1 may be equipped with a battery and a motor as a power source.

In addition, in the above-described embodiment, a millimeter wave radar is used as the radar 22, but a radar that uses a different measurement principle, such as a laser radar, may be used instead of or together with the millimeter wave radar.

<Action and effect>
Next, effects of the vehicle control system according to each of the above-described embodiments of the present invention and the modified examples of the embodiments of the present invention will be described.

The controller 10 acquires coordinates of multiple positions on the road end E based on the image captured by the camera 21, acquires coordinates of multiple positions on the road end E based on the position information of the measured object measured by the radar 22, combines the coordinates of multiple positions on the road end E acquired based on the image captured by the camera 21 with the coordinates of multiple positions on the road end E acquired based on the position information of the measured object measured by the radar 22 to generate a sequence of coordinate points of multiple positions on the road end E, controls the electric power steering 33 so that the vehicle 1 approaches the sequence of coordinate points, and controls the brake 32 so that the vehicle 1 stops after approaching the sequence of coordinate points. In other words, the controller 10 makes the vehicle 1 approach the sequence of coordinate points that combines the coordinates of the road end E from each of the camera 21 and the radar 22, so that the vehicle 1 can approach the road end E without coming into contact with the coordinates that protrude further toward the road side. Therefore, even if the coordinates of the road end E from each of the camera 21 and the radar 22 each contain an error, the vehicle 1 does not approach the road end E excessively. This means that highly reliable roadside positions can be obtained.

REFERENCE SIGNS LIST 1 vehicle 10 controller 10a processor 10b memory 21 camera 22 radar 23 vehicle speed sensor 24 acceleration sensor 25 yaw rate sensor 26 steering angle sensor 27 accelerator sensor 28 brake sensor 29 positioning system 30 navigation system 31 engine 32 brake 33 electric power steering E road edge IL _L left virtual line IL _R right virtual line OL lane marking BL lane marking TP target driving trajectory

Claims (1)

A vehicle control system that detects a road edge position by a sensor and stops a vehicle at the road edge,
A camera that captures an image of the area in front of the vehicle;
a radar for scanning the periphery of the vehicle to measure the position of an object to be measured;
a controller configured to control a steering device and a braking device of the vehicle to move the vehicle to a roadside and stop the vehicle based on the image captured by the camera and the position information of the object measured by the radar;
having
The controller:
Acquiring coordinates of a plurality of positions on the road edge based on the images captured by the camera;
acquiring coordinates of a plurality of positions on the road edge based on position information of the object measured by the radar;
generating a sequence of coordinate points of the multiple positions on the road edge by combining the coordinates of the multiple positions on the road edge obtained based on the image captured by the camera and the coordinates of the multiple positions on the road edge obtained based on the position information of the object measured by the radar;
controlling the steering device so that the vehicle approaches the sequence of coordinate points;
and controlling the braking device so that the vehicle is stopped after the vehicle approaches the sequence of coordinate points.
A vehicle control system comprising:

Images