JP7650584B2 - Collision avoidance control device - Google Patents

Description

The present invention relates to a device that is mounted on a vehicle and performs control to avoid collisions between the vehicle and an object.

Collision avoidance control is known, which is installed in vehicles such as automobiles to determine the possibility of a collision between the vehicle and an object, and if there is a high possibility of a collision, to slow down or stop the vehicle to avoid the collision.

Collision avoidance control is required not only to avoid rear-end collisions with objects ahead of the vehicle when the vehicle is traveling straight ahead, but also to avoid collisions with moving objects such as pedestrians or two-wheeled vehicles crossing the intersection when the vehicle is turning at an intersection and traveling straight ahead in the same direction as the vehicle before turning. However, there is no established control for avoiding collisions between a vehicle turning at an intersection and a moving object crossing the intersection, and various proposals have been made by vehicle manufacturers and others (see, for example, Patent Document 1).

JP 2017-224164 A

The object of the present invention is to provide a collision avoidance control device that can avoid a collision between a vehicle and a moving object when the vehicle turns at an intersection, without putting the moving object crossing the intersection at risk of colliding with the vehicle.

In order to achieve the above object, the collision avoidance control device of the present invention is a device that is mounted on a vehicle and performs control to avoid collision between the vehicle and an object, and includes a position estimation means for estimating the position of the vehicle, an object recognition means for recognizing objects present in a target area around the vehicle, and a vehicle speed adjustment means for slowing down or stopping the vehicle so that it does not enter the intersection when it is determined that the vehicle's movement path is a path that turns at an intersection ahead from the position estimated by the position estimation means, the object recognized by the object recognition means is a moving body moving toward the intersection, and there is a possibility that the vehicle will collide with the moving body in the intersection.

With this configuration, when a vehicle is turning at an intersection ahead and there is a possibility that the vehicle will collide with a moving object within the intersection, the vehicle will slow down or stop so that it does not enter the intersection.

One possible control for avoiding a collision between a vehicle and a moving object in an intersection is to stop the vehicle just before the moving object's path through the intersection. In this control, the vehicle changes direction (steers) while slowing down and stops with its front facing the moving object. Therefore, even if a collision between the vehicle and the moving object can be avoided, the vehicle will approach the moving object, and the moving object will face the risk of colliding with the vehicle.

When there is a possibility of a collision between a vehicle turning at an intersection and a moving object crossing the intersection, if the vehicle does not enter the intersection, the vehicle will not approach the moving object, and the moving object will not be exposed to the risk of a collision with the vehicle, and a collision between the vehicle and the moving object can be avoided.

The vehicle speed adjustment means may determine that there is a possibility of a collision between the vehicle and the moving body when, on the high-precision map, the path traveled by the moving body and the path traveled by the vehicle intersect within an intersection and it is predicted that the vehicle and the moving body will arrive at the intersection at the same time.

The vehicle's travel route is a route planned in advance from information obtained by placing the vehicle on a high-precision map, and the travel route information includes the target vehicle speed at each point on the travel route. Therefore, the time it takes for the vehicle to reach an intersection can be accurately calculated from the target vehicle speed at each point. As a result, it is possible to accurately predict whether the vehicle and the moving object will arrive at the intersection at the same time, and to accurately determine the possibility of a collision between the vehicle and the moving object.

According to the present invention, when a vehicle turns at an intersection, it is possible to avoid a collision between the vehicle and a moving object crossing the intersection without putting the moving object at risk of colliding with the vehicle.

1 is a block diagram showing an electrical configuration of a vehicle equipped with a collision avoidance control device according to an embodiment of the present invention; FIG. 2 is a block diagram showing a functional configuration of an autonomous driving ECU. 11 is a flowchart showing a procedure for a left turn collision avoidance process. 1 is a diagram illustrating the positions of a vehicle and a moving object when the vehicle turns left at an intersection, showing a state at the start of a left-turn collision avoidance process. FIG. FIG. 2 is a diagram illustrating the positions of a vehicle and a moving object when the vehicle turns left at an intersection, in which the vehicle is stopped at a stopping position just before the intersection.

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

<Vehicle configuration>
FIG. 1 is a block diagram showing the electrical configuration of a vehicle 1 equipped with a collision avoidance control device according to an embodiment of the present invention.

Vehicle 1 is equipped with an autonomous driving function and can travel autonomously without the user's driving operations.

Vehicle 1 is equipped with multiple ECUs (Electronic Control Units) to control various parts. Each ECU has a microcontroller unit (microcomputer), which includes, for example, a CPU, a non-volatile memory such as a flash memory, and a volatile memory such as a DRAM (Dynamic Random Access Memory).

The multiple ECUs include a drive ECU 11, a steering ECU 12, a brake ECU 13, a meter ECU 14, and a body ECU 15. The drive ECU 11, the steering ECU 12, the brake ECU 13, the meter ECU 14, and the body ECU 15 are connected to enable communication according to a CAN (Controller Area Network) communication protocol, i.e., CAN communication.

The drive ECU 11 is a control unit that controls the drive device 21 of the vehicle 1. The drive device 21 may be configured to have an engine as a drive source, a motor as a drive source, or both an engine and a motor as drive sources. The drive device 21 includes a transmission that changes the speed of the drive force from the drive source and outputs it as necessary.

The steering ECU 12 is a control unit that controls the steering device 22 of the vehicle 1. The steering device 22 is, for example, an electric power steering device that applies the torque of an electric motor to a steering mechanism. The steering mechanism includes, for example, a rack-and-pinion steering gear, and is configured such that when the rack shaft moves in the vehicle width direction due to the torque of the electric motor, the left and right steered wheels turn left and right in accordance with the movement of the rack shaft.

The brake ECU 13 is a control unit that controls the braking device 23 of the vehicle 1. The braking device 23 may be hydraulic or electric. The hydraulic braking device 23 is equipped with a brake actuator, and the function of this brake actuator distributes hydraulic pressure to the wheel cylinders of the brakes provided on each wheel, and the hydraulic pressure applies braking force from each brake to the wheels, including the drive wheels.

The meter ECU 14 is a control unit that controls each part of the meter panel (not shown) of the vehicle 1. The meter panel is provided with instruments that display vehicle speed and engine RPM, as well as displays such as a liquid crystal display for displaying various information. In addition, an emergency stop switch 24 that is operated to issue an instruction to stop the automatic driving in an emergency is connected to the meter ECU 14.

The body ECU 15 is a control unit that controls various parts of the vehicle 1 that need to operate even when the ignition switch is off, such as the left and right turn signals and the door lock motors.

The multiple ECUs also include an autonomous driving ECU 31, a lidar ECU 32, and a monocular camera ECU 33 as control units for the autonomous driving function.

The automatic driving ECU 31 is the control center for automatic driving control. The automatic driving ECU 31 is connected to the drive ECU 11, steering ECU 12, brake ECU 13, meter ECU 14, and body ECU 15 so as to be able to communicate via CAN.

An omnidirectional lidar (LiDAR: Light Detection And Ranging) 34 is connected to the autonomous driving ECU 31, for example, via an Ethernet standard communication cable. The omnidirectional lidar 34 emits laser light in all directions 360°, receives reflected light from objects present within the search range with an optical sensor, and outputs a detection signal according to the reflected light. The detection signal from the omnidirectional lidar 34 is input to the autonomous driving ECU 31.

The GPS receiver 35 is also connected to the automatic driving ECU 31 via, for example, a USB (Universal Serial Bus) standard communication cable. The GPS receiver 35 is a receiver that receives positioning signals from GPS (Global Positioning System) satellites. The positioning signals received by the GPS receiver 35 are input from the GPS receiver 35 to the automatic driving ECU 31.

The LIDAR ECU 32 is connected to the autonomous driving ECU 31 so as to be able to communicate with it, for example, via an Ethernet standard communication cable. Six LIDARs 36 are connected to the LIDAR ECU 32. The LIDARs 36 irradiate a search range with laser light, receive reflected light from objects present within the search range with an optical sensor, and output a detection signal according to the reflected light. The LIDARs 36 are, for example, disposed at the left end, center, and right end of the front bumper of the vehicle 1, and the left end, center, and right end of the rear bumper. The detection signals output from each LIDAR 36 are input to the LIDAR ECU 32. The LIDAR ECU 32 processes the detection signals output from each LIDAR 36, and transmits the data obtained by the processing to the autonomous driving ECU 31.

The monocular camera ECU 33 is communicatively connected to the autonomous driving ECU 31 via, for example, a USB standard communication cable. A monocular camera 37 is connected to the monocular camera ECU 33. The monocular camera 37 is a camera that can continuously capture still images of the search range in front of the vehicle 1 at a predetermined frame rate. The monocular camera ECU 33 receives image signals of still images that are continuously output from the monocular camera 37. The monocular camera ECU 33 processes the image signals input from the monocular camera 37, and transmits the image data obtained by this processing to the autonomous driving ECU 31.

<Autonomous driving ECU>
FIG. 2 is a block diagram showing the functional configuration of the automatic driving ECU 31.

The autonomous driving ECU 31 includes an object recognition unit 41, a self-position estimation unit 42, a surrounding information integration unit 43, a route planning unit 44, a safety confirmation unit 45, and a vehicle control unit 46. These functional processing units are realized in software by program processing, or by hardware such as a logic circuit.

The object recognition unit 41 recognizes objects such as other vehicles and pedestrians around the vehicle 1 from information on the distance to the object (vehicle, pedestrian, building, curb, or other obstacle) obtained from the detection signal of the omnidirectional lidar 34 and from images captured by the monocular camera 37.

The self-position estimation unit 42 estimates the position (self-position) of the vehicle 1 by matching the point cloud data acquired from the detection signal of the omnidirectional lidar 34 with high-precision map data (point cloud data) 47, which is data of a high-precision map. The high-precision map is a high-precision three-dimensional map, and the high-precision map data 47 includes information such as road width, dividing lines, shoulder lines, stop lines at intersections (traffic lights), crosswalks, and signs. The high-precision map data 47 may be stored in a memory built into the microcomputer of the automatic driving ECU 31, or may be stored in a HDD (Hard Disk Drive) connected to the automatic driving ECU 31. The self-position estimation unit 42 also integrates the self-position estimated by matching the point cloud data with the self-position based on the positioning signal received by the GPS receiver 35 to improve the estimation accuracy of the self-position.

The surrounding information integration unit 43 receives as input the object recognition results by the object recognition unit 41, the self-position estimation results by the self-position estimation unit 42, and data obtained by processing the detection signals output from each LIDAR 36 by the LIDAR ECU 32 (see FIG. 1). High-precision map data 47 is also input to the surrounding information integration unit 43. The surrounding information integration unit 43 creates surrounding information integrated map data in which the vehicle 1, vehicles other than the vehicle 1, and objects such as pedestrians are arranged on a high-precision map. The surrounding information integration unit 43 then outputs the map information and object recognition information to an HMI (Human Machine Interface) device 48 such as a display arranged inside the vehicle 1.

The surrounding information integrated map data is input to the route planning unit 44 from the surrounding information integration unit 43. From the surrounding information integrated map data, the route planning unit 44 plans a route for moving the vehicle 1 to the target location and a target vehicle speed at each point on the route. The route planning unit 44 then outputs the planned route (hereinafter referred to as the "planned route") and planned route data including the target vehicle speed to the HMI device 48.

The safety confirmation unit 45 receives surrounding information integrated map data from the surrounding information integration unit 43. The safety confirmation unit 45 also receives planned route data from the route planning unit 44. The safety confirmation unit 45 confirms the safety of the route of the vehicle 1 from the surrounding information integrated map data and the planned route data.

The vehicle control unit 46 receives planned route data from the route planning unit 44. The vehicle control unit 46 also receives the results of the check by the safety check unit 45. Based on the planned route data and the check results for safety on the route of the vehicle 1, the vehicle control unit 46 outputs commands to ECUs that control the operation of each part of the vehicle 1, such as the drive ECU 11, steering ECU 12, and brake ECU 13, so that the vehicle 1 travels along the planned route.

<Collision avoidance processing when turning left>
4A and 4B are diagrams illustrating the positions of the vehicle 1 and the moving object M when the vehicle 1 turns left at an intersection C. In the flowchart of FIG.

For example, if the planned route planned by the route planning unit 44 includes a left turn at an intersection C when the vehicle 1 is traveling autonomously using the autonomous driving function, the autonomous driving ECU 31 starts a left turn collision avoidance process when the vehicle 1 reaches a position a predetermined distance before the intersection C, and first the safety confirmation unit 45 performs a pre-left turn safety confirmation process (step S11). The intersection C is a crossroads, a T-junction, or a portion where multiple roads intersect. The intersection C refers to, for example, a portion enclosed by lines connecting the end points (starting points) of the side lines of the roads on the intersection side, and if the roads intersecting at the intersection C have stop lines or crosswalks, the intersection C refers to a portion closer to the center of the intersection C than the stop lines and including the crosswalk.

In the pre-left-turn safety confirmation process, for example, as shown by the two-dot chain line in FIG. 4A, a rectangular area from the center of the vehicle 1 in the vehicle width direction to its left is set as target area A, and it is confirmed whether or not a moving body M proceeding toward intersection C is recognized by the object recognition unit 41 in target area A. Target area A is set, for example, to the width from the center of the vehicle 1 in the vehicle width direction to the edge of the road, and includes the area from the vehicle 1 to just before the intersection C and an area of a certain length behind the vehicle 1. If a sidewalk is provided, target area A includes the sidewalk.

If there is no moving object M in the target area A proceeding toward the intersection C, it is determined that safety has been confirmed before the vehicle 1 starts to turn left, and the result of the pre-left-turn safety check is OK (YES in step S12). In this case, the vehicle control unit 46 performs a left-turn execution process. In the left-turn execution process, the vehicle control unit 46 controls the operation of each part of the vehicle 1 via the drive ECU 11, steering ECU 12, brake ECU 13, etc. so that the vehicle 1 turns left at the intersection C and proceeds (step S13). After the left-turn execution process, the left-turn collision avoidance process ends.

When a moving object M moving toward an intersection C is present in the target area A, the moving path of the moving object M is predicted on the high-precision map on the assumption that the moving object M will cross the intersection C. When the predicted moving path (hereinafter referred to as the "predicted path") intersects with the planned path of the vehicle 1 that turns left at the intersection C within the intersection C, the vehicle arrival time until the vehicle 1 reaches the intersection of the planned path and the predicted path is calculated from the target vehicle speed at each point included in the information on the planned path of the vehicle 1. In addition, the moving object arrival time until the moving object M reaches the intersection of the planned path and the predicted path is calculated from the moving speed of the moving object M. Then, the vehicle arrival time and the moving object arrival time are compared, and if the difference between them is equal to or less than a predetermined value, it is predicted that the vehicle 1 and the moving object M will arrive at the intersection of the planned path and the predicted path at the same time, and the result of the safety check before the left turn is judged to be NG (NO in step S12). On the other hand, if the difference between the vehicle arrival time and the moving object arrival time is greater than a predetermined value, it is determined that even if the vehicle 1 turns left at the intersection C and proceeds, a collision between the vehicle 1 and the moving object M will not occur, and the result of the pre-left-turn safety check is determined to be OK (YES in step S12).

If the result of the safety check before turning left is NG, the route planning unit 44 judges whether to decelerate and stop the vehicle 1 (step S14). In other words, it is determined whether to perform a stopping process in which the vehicle 1 is decelerated and stopped, or a deceleration process in which the vehicle 1 is only decelerated but not stopped. The decision as to whether to perform a stopping process or a deceleration process is based on the distances from the vehicle 1 and the moving body M to the intersection C and the moving speeds of the vehicle 1 and the moving body M. Specifically, it is determined whether the moving body M will pass through the intersection between the predicted route of the moving body M and the planned route of the vehicle 1 by the time the vehicle 1 enters the intersection C only by decelerating the vehicle 1. If it is determined that the moving body M will pass through, it is determined to perform a deceleration process (NO in step S14). If it is determined that the moving body M will not pass through, it is determined to perform a stopping process (YES in step S14).

In the deceleration process, the vehicle control unit 46 controls the operation of each part of the vehicle 1 so that the vehicle 1 decelerates (step S15: deceleration process). While the deceleration process is being performed, the safety confirmation unit 45 repeatedly performs the pre-left turn safety confirmation process (step S11). Then, when the moving body M disappears from the target area A while the vehicle 1 is decelerating due to the deceleration process, it is determined that safety has been confirmed before the vehicle 1 starts to turn left, and the result of the pre-left turn safety confirmation is OK (YES in step S12), and the left turn execution process is performed by the vehicle control unit 46 (step S13).

In the stopping process, the route planning unit 44 sets the position immediately before the intersection C as the stopping position, and re-plans the route so that the vehicle 1 stops temporarily at the stopping position. Then, according to the re-planned planned route, the vehicle control unit 46 controls the operation of each part of the vehicle 1 so that the vehicle 1 stops at the stopping position (step S16: stopping process).

After the stopping process is started, it is determined whether the stopping process is completed, that is, whether the vehicle 1 has stopped at the stopping position (step S17). If the stopping process is not completed (NO in step S17), the safety confirmation unit 45 performs the pre-left turn safety confirmation process again (step S11). If the moving body M is no longer present in the target area A before the stopping process is completed, that is, before the vehicle 1 stops, the safety confirmation unit 45 determines that the pre-left turn safety confirmation is OK (YES in step S12), assuming that safety has been confirmed before the vehicle 1 starts to turn left. In this case, the vehicle control unit 46 performs the left turn execution process (step S13). After the left turn execution process, the left turn collision avoidance process ends.

If safety is not confirmed in the pre-left-turn safety confirmation process (NO in step S12), it is determined again whether to decelerate and stop vehicle 1 (step S14). For example, if the moving speed of moving body M increases and a situation arises in which moving body M can pass the intersection between the predicted route of moving body M and the planned route of moving body 1 before entering intersection C simply by decelerating vehicle 1, the stop process is switched to the deceleration process (NO in step S14).

When the stopping process continues and the vehicle 1 stops at the stopping position just before the intersection C as shown in FIG. 4B, it is determined that the stopping process is completed (YES in step S17). After that, the vehicle control unit 46 controls the operation of each part of the vehicle 1 so that the vehicle 1 is maintained stopped at the stopping position (step S18: stop maintenance process).

After the stop maintenance process is started, the safety confirmation unit 45 performs a departure safety confirmation process (step S19). In the departure safety confirmation process, it is confirmed whether the moving body M has passed through the intersection between the predicted path of the moving body M and the planned path of the vehicle 1.

If the moving body M has not yet passed the intersection between the predicted route of the moving body M and the planned route of the vehicle 1 (NO in step S20), the safety confirmation unit 45 judges that the result of the safety confirmation (start safety confirmation) when the vehicle 1 starts is NG (NO in step S12). The start safety confirmation process is repeated until the result of the start safety confirmation is OK, that is, until the moving body M has passed the intersection between the predicted route of the moving body M and the planned route of the vehicle 1.

When the moving body M has passed through the intersection between the predicted route of the moving body M and the planned route of the vehicle 1, the safety confirmation unit 45 judges that the result of the departure safety confirmation is OK (YES in step S20). Then, the vehicle control unit 46 performs a left turn execution process (step S13), and the vehicle 1 starts moving. After starting, the vehicle 1 enters the intersection C, turns left at the intersection C, and proceeds. After the left turn execution process, the left turn collision avoidance process ends.

<Action and effect>
As described above, when vehicle 1 turns at an intersection C ahead and there is a possibility that vehicle 1 will collide with a moving body M within the intersection C, vehicle 1 will slow down or stop so that vehicle 1 will not enter the intersection C.

As a control for avoiding a collision between vehicle 1 and moving body M at intersection C, for example, control for stopping vehicle 1 just before the moving path of moving body M at intersection C can be considered. In this control, vehicle 1 decelerates while changing its direction of travel (while steering) at intersection C, and stops with its front facing moving body M. Therefore, even if a collision between vehicle 1 and moving body M can be avoided, vehicle 1 approaches moving body M, so moving body M faces the risk of a collision with vehicle 1.

When there is a possibility of a collision between vehicle 1 turning at intersection C and moving body M crossing intersection C, vehicle 1 does not enter intersection C, so vehicle 1 does not approach moving body M, and therefore it is possible to avoid a collision between vehicle 1 and moving body M without putting moving body M at risk of colliding with vehicle 1.

When, on the high-precision map, the planned route along which the moving body M will travel and the predicted route of the vehicle 1 intersect at an intersection C, and it is predicted that the vehicle 1 and the moving body M will arrive at the intersection C at the same time, it is determined that there is a possibility that the vehicle 1 and the moving body M will collide. The planned route is a route that is planned in advance from information obtained by placing the vehicle 1 on the high-precision map, and the information on the planned route includes the target vehicle speed at each point on the planned route. Therefore, the time until the vehicle 1 reaches the intersection C can be accurately calculated from the target vehicle speed at each point. As a result, it is possible to accurately predict whether the vehicle 1 and the moving body M will arrive at the intersection C at the same time, and the possibility of a collision between the vehicle 1 and the moving body M can be accurately determined.

<Modification>
Although one embodiment of the present invention has been described above, the present invention can be embodied in other forms.

For example, in the above embodiment, the case where the vehicle 1 turns left at the intersection C and proceeds is taken up, but even when the vehicle 1 turns right at the intersection C and proceeds, a process similar to the left turn collision avoidance process is performed, thereby making it possible to avoid a collision between the vehicle 1 and the moving body M. In this case, instead of the left turn safety confirmation process, a right turn safety confirmation process is performed, and a rectangular area from the center of the vehicle 1 in the vehicle width direction to its right side is set as the target area A, and it is confirmed whether the moving body M proceeding toward the intersection C is recognized in the target area A by the object recognition unit 41, and if the moving body M is recognized, the possibility of a collision between the vehicle 1 and the moving body M is determined.

Although vehicle 1 equipped with an autonomous driving function has been described, the present invention may also be applied to vehicles that are not equipped with an autonomous driving function and that are equipped with a collision avoidance function using collision avoidance control.

In addition, various design modifications can be made to the above-mentioned configuration within the scope of the claims.

1: Vehicle 31: Autonomous driving ECU (collision avoidance control device)
41: Object recognition unit (object recognition means)
42: Self-position estimation unit (position estimation means)
45: Safety confirmation section (vehicle speed adjustment means)
46: Vehicle control unit (vehicle speed adjustment means)
47: High-precision map data A: Target area C: Intersection M: Moving object

Claims (1)

A device mounted on a vehicle and performing control to avoid a collision between the vehicle and an object,
A position estimation means for estimating a position of the vehicle;
an object recognition means for recognizing objects present in a target area around the vehicle;
a vehicle speed adjustment means for slowing down or stopping the vehicle so as not to enter the intersection when it is determined that the movement route of the vehicle is a route that turns at an intersection ahead from the position estimated by the position estimation means, an object recognized by the object recognition means is a moving body moving toward the intersection, and there is a possibility that the vehicle will collide with the moving body in the intersection,
the target area includes an area from the vehicle to just before the intersection and an area of a certain length behind the vehicle,
The vehicle speed adjustment means is
when, on the high-precision map, the path along which the moving body will travel and the path along which the vehicle will travel intersect at the intersection and it is predicted that the vehicle and the moving body will arrive at the intersection of a predicted path along which the moving body will travel and the path along which the vehicle will travel at the same time, it is determined that there is a possibility of a collision between the vehicle and the moving body;
A collision avoidance control device that determines whether the moving body will be able to pass the intersection between the predicted route and the travel route by the time the vehicle enters the intersection by decelerating the vehicle alone, and if it is determined that the moving body will pass the intersection, performs a deceleration process that only decelerates the vehicle but does not stop it, and if it is determined that the moving body will not pass the intersection, performs a stop process that decelerates the vehicle and stops it.

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