AUTONOMOUS DRIVING CONTROL SYSTEM FOR VEHICLE

• US 20140222278A1
• Filed: 08/23/2012
• Published: 08/07/2014
• Est. Priority Date: 08/25/2011
• Status: Active Grant

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Fujita, Susumu
• Granted Patent: US 9,182,761 B2
• Time in Patent Office: Days
• US Class Current: 701/25
• CPC Class Codes: B60W 2554/4041 Position
• CPC Class Codes: B60W 2554/801 Lateral distance
• CPC Class Codes: B60W 2554/804 Relative longitudinal speed
• CPC Class Codes: B60W 2556/20 Data confidence level
• CPC Class Codes: B60W 30/09 Taking automatic action to avoid collision, e.g. braking and steering
• CPC Class Codes: G05D 1/0212 with means for defining a desired trajectory involving a plurality of land vehicles G05D1/0287
• CPC Class Codes: G08G 1/165 for passive traffic, e.g. including static obstacles, trees
• CPC Class Codes: G08G 1/166 for active traffic, e.g. moving vehicles, pedestrians, bikes

Abstract

Information regarding a vehicle is acquired by a vehicle information acquisition unit provided in the vehicle, and an object to be avoided is detected by an avoidance-target object detection unit. On the basis of the vehicle information and the distance and angle of the object to be avoided, the location and amount of movement of the object to be avoided are calculated by a peripheral information recognition unit, and the calculation accuracy of the location and amount of movement of the object to be avoided are determined by a driving maneuver determination unit. On the basis of the calculation accuracy of the location and amount of movement of the object to be avoided, a driving maneuver for avoiding the object to be avoided is determined, and autonomous driving control is implemented in accordance with the driving maneuver that is determined.

Claims

1. An autonomous driving control system for a vehicle for detecting the positions of an own vehicle and an avoidance object existing around the own vehicle, determining a course to a destination, and carrying out autonomous driving control, comprising:

a driving strategy determination unit configured to determine a driving strategy to avoid the avoidance object according to a distance between the own vehicle and the avoidance object and computation accuracy levels of a position and moving amount of the avoidance object, wherein

the autonomous driving control system controls the own vehicle according to a control instruction value that is determined to execute autonomous driving control on the own vehicle and corresponds to the driving strategy determined by the driving strategy determination unit.

2. The autonomous driving control system for a vehicle according to claim 1, wherein if it is determined that the computation accuracy of the position of the avoidance object is high and the avoidance object is at a near distance and that the computation accuracy of the moving amount of the avoidance object is low,

a driving strategy is chosen to avoid the avoidance object as an object that approaches at a predetermined speed.

3. The autonomous driving control system for a vehicle according to claim 2, wherein

if it is determined that the computation accuracy of the position of the avoidance object is high and the avoidance object is at a near distance and that the computation accuracy of the moving amount of the avoidance object is high,

a driving strategy is chosen to avoid the avoidance object as an object that moves at a detected speed.

4. The autonomous driving control system for a vehicle according to claim 1, wherein

if it is determined that the computation accuracy of the position of the avoidance object is high and the avoidance object is at a far distance and that the computation accuracy of the moving amount of the avoidance object is low,

a driving strategy is chosen to avoid the avoidance object as an object that is stationary.

5. The autonomous driving control system for a vehicle according to claim 4, wherein

if it is determined that the computation accuracy of the position of the avoidance object is high and the avoidance object is at a far distance and that the computation accuracy of the moving amount of the avoidance object is high,

a driving strategy is chosen to avoid the avoidance object as an object that moves at a detected speed.

6. The autonomous driving control system for a vehicle according to claim 1, wherein the driving strategy determination unit has:

a system configuration database that stores the computation accuracy of a position of the avoidance object, the computation accuracy of a moving amount thereof, and a system configuration to execute a driving strategy corresponding to these pieces of computation accuracy; and

a system operation level judgment part that judges and determines a system configuration to execute autonomous driving control according to the computation accuracy of the position of the avoidance object and the computation accuracy of the moving amount thereof.

7. The autonomous driving control system for a vehicle according to claim 6, wherein the driving strategy determination unit judges that:

(i) the computation accuracy of the position of the avoidance object is high if the position of the avoidance object is directly obtained and if the avoidance object and own vehicle are detected at a distance equal to or lower than a distance threshold;

(ii) the computation accuracy of the position of the avoidance object is low if the position of the avoidance object is not directly obtained and if the avoidance object and own vehicle are detected at a distance greater than the distance threshold;

(iii) the computation accuracy of the moving amount of the avoidance object is high if it is judged that the computation accuracy of the position of the avoidance object and that of a moving amount of the own vehicle are high; and

(iv) the computation accuracy of the moving amount of the avoidance object is low if it is judged that the computation accuracy of at least one of the position of the avoidance object and the moving amount of the own vehicle is low.

8. The autonomous driving control system for a vehicle according to claim 6, wherein the driving strategy determination unit judges that:

the detection accuracy of the moving amount of the own vehicle is high if the own vehicle is not driving on a slippery road; and

the detection accuracy of the moving amount of the own vehicle is low if the own vehicle is driving on a slippery road.

9. The autonomous driving control system for a vehicle according to claim 7, wherein:

the system operation level judgment part has an position accuracy judgment part of own vehicle, the position accuracy judgment part of own vehicle judging

that the detection accuracy of a position of the own vehicle is high if the position of the own vehicle is detected in the order of a first threshold that is preset as a judgment value to judge a detection accuracy level of the position of the own vehicle and

that the detection accuracy of the position of the own vehicle is low if the position of the own vehicle is detected in the order of a second threshold that is preset as a judgment value to judge a detection accuracy level of the position of the own vehicle; and

the driving strategy determination unit determines a driving strategy involving driving control to a predetermined destination according to the detection accuracy of the position of the own vehicle judged by the position accuracy judgment part of own vehicle.

10. The autonomous driving control system for a vehicle according to claim 7, wherein the driving strategy determination unit avoids the avoidance object according to a recognition state of the moving amount of the avoidance object at the timing determined by a predetermined collision time (TTC) and vehicle-to-vehicle time interval (THW).

11. The autonomous driving control system for a vehicle according to claim 9, wherein

if the position accuracy judgment part of own vehicle determines that the detection accuracy of the position of the own vehicle is low, the driving control to the predetermined destination is suspended for a judged period and only the driving control to avoid the avoidance object is carried out.

12. The autonomous driving control system for a vehicle according to claim 11, wherein when the detection accuracy of the position of the own vehicle is judged to be low and only the driving control to avoid the avoidance object is carried out, the suspended driving control to the destination is resumed if the detection accuracy of the position of the own vehicle is judged to have been changed from low to high and is updated accordingly.

13. The autonomous driving control system for a vehicle according to claim 1, wherein

when the driving strategy determined by the driving strategy determination unit is changed, if control instruction values corresponding to a plurality of candidate driving strategies to be chosen after the change include a control instruction value that contains a motion vector that is similar to a motion vector of the own vehicle contained in a control instruction value corresponding to the driving strategy executed before the change, a control instruction value to be selected after the change contains the similar motion vector.

14. The autonomous driving control system for a vehicle according to claim 1 further comprising:

a vehicle information acquisition unit acquiring at least the position, speed, and steering angle of the own vehicle;

an avoidance object detection unit detecting the avoidance object from among objects existing around the own vehicle and detecting a distance and an angle between the detected avoidance object and the own vehicle; and

a peripheral information recognition unit recognizing a driving course along which the own vehicle can drive, computing the position of the avoidance object with respect to the own vehicle according to the position of the own vehicle acquired by the vehicle information acquisition unit and the distance and angle between the avoidance object and the own vehicle detected by the avoidance object detection unit, and computing the moving amount of the avoidance object according to the computed position of the avoidance object and a moving amount of the own vehicle computed according to the speed and steering angle of the own vehicle acquired by the vehicle information acquisition unit.

15. An autonomous driving control system for a vehicle for detecting the positions of an own vehicle and objects existing around the own vehicle, determining a course to a destination, and carrying out autonomous driving control, characterized in that the system includes:

a vehicle information acquisition means that acquires at least the position, speed, and steering angle of the own vehicle;

an avoidance object detection means that detects an avoidance object from among the objects existing around the own vehicle and detects a distance and an angle between the detected avoidance object and the own vehicle;

a peripheral information recognition means that recognizes a driving course along which the own vehicle can drive, computes a position of the avoidance object with respect to the own vehicle according to the position of the own vehicle acquired by the vehicle information acquisition means and the distance and angle between the avoidance object and the own vehicle detected by the avoidance object detection means, and computes a moving amount of the avoidance object according to the computed position of the avoidance object and a moving amount of the own vehicle computed according to the speed and steering angle of the own vehicle acquired by the vehicle information acquisition means;

a driving strategy determination means that determines the computation accuracy of the position of the avoidance object according to a comparison result of the distance between the own vehicle and the avoidance object with a distance threshold and whether or not the position of the avoidance object has been directly obtained, determines the computation accuracy of the moving amount of the avoidance object according to the computation accuracy of the position of the avoidance object and that of the moving amount of the own vehicle, and determines a driving strategy to specify driving control to avoid the avoidance object according to the computation accuracy of each of the position and moving amount of the avoidance object; and

a control instruction value determination means that determines and outputs a control instruction value to control the own vehicle so that autonomous driving control corresponding to the driving strategy determined by the driving strategy determination means is executed on the own vehicle.