Control device for vehicle

• US 10,358,128 B2
• Filed: 01/24/2018
• Issued: 07/23/2019
• Est. Priority Date: 03/16/2017
• Status: Active Grant

• Current Assignee: Subaru Corp.
• Original Assignee: Subaru Corp.
• Inventors: Yoneda, Takeshi, Ienaga, Hiroshi, Kobayashi, Takahiro, Sakaguchi, Shinichi
• Primary Examiner(s): Black, Thomas G
• Assistant Examiner(s): Louie, Wae L
• Application Number:
  US15/879,205
• Publication Number:
  US 20180265081A1
• Time in Patent Office: 545 Days
• Field of Search: 701 70
• CPC Class Codes: B60T 2201/022 Collision avoidance systems
• CPC Class Codes: B60T 2210/12 Friction
• CPC Class Codes: B60T 7/12 for automatic initiation; for initiation not subject to will of driver or passenger limiting speed of vehicles other than rail vehicles B60K31/00
• CPC Class Codes: B60T 7/22 initiated by contact of vehicle, e.g. bumper, with an external object, e.g. another vehicle , or by means of contactless obstacle detectors mounted on the vehicle
• CPC Class Codes: B60T 8/17 Using electrical or electronic regulation means to control braking detecting or indicating faulty operation B60T8/885
• CPC Class Codes: B60W 2552/40 Coefficient of friction
• CPC Class Codes: B60W 30/09 Taking automatic action to avoid collision, e.g. braking and steering
• CPC Class Codes: B60W 30/0956 the prediction being responsive to traffic or environmental parameters
• CPC Class Codes: B60W 40/068 Road friction coefficient

Abstract

A control device for a vehicle includes a predictor and a controller. The predictor is configured to predict, on the basis of change information, whether or not the vehicle will collide with a frontward obstacle, on the condition that a brake operation by a driver has been performed. The change information is information regarding a change in a friction coefficient of a road surface frontward of the vehicle. The controller is configured to control brake power of the vehicle on the basis of the change information, on the condition that a prediction is made that the vehicle will collide with the obstacle.

Claims

1. A control device for a vehicle, the control device comprising:

a predictor configured to predict, on a basis of change information, whether or not the vehicle will collide with a frontward obstacle, on a condition that a brake operation by a driver has been performed, the change information including information regarding a change in a friction coefficient of a road surface frontward of the vehicle; and

a controller configured to, after the brake operation by the driver is performed, control a brake power of the vehicle on the basis of the change information, on a condition that a prediction is made that the vehicle will collide with the obstacle.

2. The control device for the vehicle according to claim 1, wherein the controller controls the brake power of the vehicle, to bring a braking distance of the vehicle to a value decided on a basis of a driver'"'"'s intended braking distance, on the condition that the prediction is made that the vehicle will collide with the obstacle.

3. The control device for the vehicle according to claim 2, wherein the change information further includes information indicating a distance from the vehicle to a point of decrease, and information indicating the friction coefficient of the road surface frontward of the point of decrease, the point of decrease being a point at which the friction coefficient of the road surface decreases frontward of the vehicle.

4. The control device for the vehicle according to claim 3, wherein the predictor includes:

a distance calculation unit configured to calculate a predicted braking distance on the basis of the change information, the predicted braking distance being a predicted value of the braking distance of the vehicle; and

a collision prediction unit configured to predict whether or not the vehicle will collide with the obstacle, on a basis of a comparison result of a distance from the vehicle to the obstacle with the predicted braking distance.

5. The control device for the vehicle according to claim 4, wherein the distance calculation unit applies, as a predicted value of deceleration of the vehicle frontward of the point of decrease, deceleration corresponding to the friction coefficient of the road surface frontward of the point of decrease.

6. The control device for the vehicle according to claim 3, wherein the controller includes:

a deceleration calculation unit configured to calculate target deceleration on the basis of the change information, the target deceleration being target values of deceleration frontward and rearward of the point of decrease; and

a brake power control unit configured to control the brake power of the vehicle, to bring the deceleration of the vehicle to the target deceleration.

7. The control device for the vehicle according to claim 6, wherein the deceleration calculation unit calculates, as the target deceleration frontward of the point of decrease, deceleration corresponding to the friction coefficient of the road surface frontward of the point of decrease.

8. The control device for the vehicle according to claim 6, wherein the deceleration calculation unit calculates, as the target deceleration rearward of the point of decrease, deceleration having a larger absolute value than an absolute value of current deceleration of the vehicle.

9. The control device for the vehicle according to claim 1, wherein the change information further includes information indicating a distance from the vehicle to a point of decrease calculated based on a detection result of a distribution of the friction coefficient of the road surface frontward of the vehicle, and information indicating the friction coefficient of the road surface frontward of the point of decrease calculated based on the detection result of the distribution of the friction coefficient of the road surface frontward of the vehicle, the point of decrease being a point at which the friction coefficient of the road surface decreases frontward of the vehicle.

10. The control device for the vehicle according to claim 3, wherein the predictor includes:

a distance calculation unit configured to calculate a predicted braking distance on the basis of the change information, the predicted braking distance being a predicted value of the braking distance of the vehicle; and

a collision prediction unit configured to predict whether or not the vehicle will collide with the obstacle, on a basis of a comparison result of a distance from the vehicle to the obstacle with the predicted braking distance.

11. The control device for the vehicle according to claim 10, wherein the distance calculation unit applies, as a predicted value of deceleration of the vehicle frontward of the point of decrease, deceleration corresponding to the friction coefficient of the road surface frontward of the point of decrease.

12. The control device for the vehicle according to claim 9, wherein the controller includes:

a deceleration calculation unit configured to calculate target deceleration on the basis of the change information, the target deceleration being target values of deceleration frontward and rearward of the point of decrease; and

a brake power control unit configured to control the brake power of the vehicle, to bring the deceleration of the vehicle to the target deceleration.

13. The control device for the vehicle according to claim 12, wherein the deceleration calculation unit calculates, as the target deceleration frontward of the point of decrease, deceleration corresponding to the friction coefficient of the road surface frontward of the point of decrease.

14. The control device for the vehicle according to claim 12, wherein the deceleration calculation unit calculates, as the target deceleration rearward of the point of decrease, deceleration having a larger absolute value than an absolute value of current deceleration of the vehicle.

15. The control device for the vehicle according to claim 1, wherein the controller controls the brake power of the vehicle only after the brake operation by the driver is performed.

16. The control device for the vehicle according to claim 1, wherein the obstacle is stationary.

17. The control device for the vehicle according to claim 1, wherein the road surface frontward of the vehicle includes a road that extends from the vehicle to the obstacle.

18. A control device for a vehicle, the control device comprising:

a circuitry configured to;

predict, on a basis of change information, whether or not the vehicle will collide with a frontward obstacle, on a condition that a brake operation by a driver has been performed, the change information including information regarding a change in a friction coefficient of a road surface frontward of the vehicle; and

control brake power of the vehicle, after the brake operation by the driver is performed, on the basis of the change information, on a condition that a prediction is made that the vehicle will collide with the obstacle.

19. The control device for the vehicle according to claim 18, wherein the circuitry controls the brake power of the vehicle only after the brake operation by the driver is performed.

20. The control device for the vehicle according to claim 18, wherein the road surface frontward of the vehicle includes a road that extends from the vehicle to the obstacle.