Obstacle avoidance control apparatus

• US 7,860,653 B2
• Filed: 09/20/2007
• Issued: 12/28/2010
• Est. Priority Date: 10/05/2006
• Status: Active Grant

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Joe, Shinichiro, Deguchi, Yoshitaka
• Primary Examiner(s): Black; Thomas G
• Assistant Examiner(s): Chen; Shelley
• Application Number:
  US11/858,338
• Publication Number:
  US 20080086269A1
• Time in Patent Office: 1,195 Days
• Field of Search: 701/301
• US Class Current: 701/301
• CPC Class Codes: B60W 10/20 including control of steering systems
• CPC Class Codes: B60W 2050/0031 Mathematical model of the vehicle
• CPC Class Codes: B60W 2520/105 Longitudinal acceleration
• CPC Class Codes: B60W 2520/125 Lateral acceleration
• CPC Class Codes: B60W 2520/14 Yaw
• CPC Class Codes: B60W 2520/28 Wheel speed
• CPC Class Codes: B60W 2540/10 Accelerator pedal position
• CPC Class Codes: B60W 2540/18 Steering angle
• CPC Class Codes: B60W 2552/40 Coefficient of friction
• CPC Class Codes: B60W 2554/00 Input parameters relating to objects
• CPC Class Codes: B60W 2710/207 Steering angle of wheels
• CPC Class Codes: B60W 2720/20 Sideslip angle
• CPC Class Codes: B60W 30/09 Taking automatic action to avoid collision, e.g. braking and steering
• CPC Class Codes: B60W 40/04 Traffic conditions
• CPC Class Codes: B62D 15/0265 Automatic obstacle avoidance by steering

Abstract

An obstacle avoidance control apparatus is provided with an obstacle detecting section, a first obstacle proximity distance prediction section, a second obstacle avoidance direction determining section, a target vehicle body slip angle setting section and a vehicle behavior controlling section. The obstacle detecting section detects preceding obstacles. The first obstacle proximity distance prediction section predicts a closest proximity distance between the host vehicle and a first (closest) obstacle. The second obstacle avoidance direction determining section determines a second obstacle avoidance direction to avoid the second obstacle. The target vehicle body slip angle setting section sets a target vehicle body slip angle, such that the host vehicle faces further inward of the turning direction as the proximity distance increases. The vehicle behavior controlling section controls the host vehicle so that an actual vehicle body slip angle coincides with the target vehicle body slip angle at the time of closest proximity.

Claims

1. An obstacle avoidance control apparatus comprising:

an obstacle detecting section arranged to detect first and second obstacles in front of a host vehicle, with the second obstacle being detected as being farther in front of the host vehicle than the first obstacle;

a first obstacle proximity distance prediction section configured to predict a first obstacle proximity distance between the host vehicle and the first obstacle at a time of closest proximity between the host vehicle and the first obstacle;

a second obstacle avoidance direction determining section configured to determine a second obstacle avoidance direction that is predicted to avoid the second obstacle;

a target vehicle body slip angle setting section configured to set a target vehicle body slip angle in a direction at the time of closest proximity with respect to a vehicle body center of the host vehicle, such that the host vehicle faces further inward of the second obstacle avoidance turning direction as the first obstacle proximity distance increases; and

a vehicle behavior controlling section configured to control a vehicle behavior of the host vehicle so that an actual vehicle body slip angle with respect to the vehicle body center at the time of closest proximity coincides with the target vehicle body slip angle at the time of closest proximity.

2. The obstacle avoidance control apparatus according to claim 1, wherein

the target vehicle body slip angle setting section is further configured to set the target vehicle body slip angle at the time of closest proximity so as to approach zero as the first obstacle proximity distance decreases.

3. The obstacle avoidance control apparatus according to claim 1, wherein

the target vehicle body slip angle setting section is further configured to predict a turning radius of a predicted course to be taken by the host vehicle until the host vehicle approaches the second obstacle upon avoiding the first obstacle, and

the target vehicle body slip angle setting section is further configured to set the target vehicle body slip angle in the direction at the time of closest proximity to increase such that the host vehicle faces further inward of the second obstacle turning direction as the turning radius of the predicted course decreases.

4. The obstacle avoidance control apparatus according to claim 1, wherein

the target vehicle body slip angle setting section is further configured to predict a vehicle transverse acceleration rate of the host vehicle along a predicted course to be taken by the host vehicle until the host vehicle approaches the second obstacle upon avoiding the first obstacle, and

the target vehicle body slip angle setting section is further configured to set the target vehicle body slip angle in the direction at the time of closet proximity to increase such that the host vehicle faces further inward of the second obstacle turning direction as the vehicle transverse acceleration rate of the host vehicle increases.

5. The obstacle avoidance control apparatus according to claim 1, wherein

the target vehicle body slip angle setting section is further configured to predict the yaw angle of the host vehicle when the host vehicle is in a prescribed proximity to the second obstacle, and

the target vehicle body slip angle setting section is further configured to set the target vehicle body slip angle at the prescribed proximity to the second obstacle to be equal to or less than a vehicle body slip angle at which the predicted yaw angle is achieved.

6. The obstacle avoidance control apparatus according to claim 1, wherein

the target vehicle body slip angle setting section is further configured to set the target vehicle body slip angle at the time of closest proximity to zero when the second obstacle is not detected.

7. The obstacle avoidance control apparatus according to claim 1, wherein

the target vehicle body slip angle setting section is further configured to estimate a coefficient of friction of a road surface, and

the target vehicle body slip angle setting section is further configured to increase the target vehicle body slip angle at the time of closest proximity as the coefficient of friction of the road surface value decreases.

8. An obstacle avoidance control apparatus comprising:

means for detecting first and second obstacles in front of a host vehicle, and for detecting the second obstacle being farther in front of the host vehicle than the first obstacle;

means for predicting a first obstacle proximity distance between the host vehicle and the first obstacle at a time of closest proximity between the host vehicle and the first obstacle;

means for determining a second obstacle avoidance direction that is predicted to avoid the second obstacle;

means for setting a target vehicle body slip angle in a direction at the time of closest proximity with respect to a vehicle body center of the host vehicle, such that the host vehicle faces further inward of the second obstacle avoidance turning direction as the first obstacle proximity distance increases; and

means for controlling a vehicle behavior of the host vehicle so that an actual vehicle body slip angle with respect to the vehicle body center at the time of closest proximity coincides with the target vehicle body slip angle at the time of closest proximity.

9. An obstacle avoidance control method comprising:

detecting first and second obstacles in front of a host vehicle, with the second obstacle being detected as being farther in front of the host vehicle than the first obstacle;

predicting a first obstacle proximity distance between the host vehicle and the first obstacle at a time of closest proximity between the host vehicle and the first obstacle;

determining a second obstacle avoidance direction that is predicted to avoid the second obstacle;

setting a target vehicle body slip angle in a direction at the time of closest proximity with respect to a vehicle body center of the host vehicle, such that the host vehicle faces further inward of the second obstacle avoidance turning direction as the first obstacle proximity distance increases; and

controlling a vehicle behavior of the host vehicle so that an actual vehicle body slip angle with respect to the vehicle body center at the time of closest proximity coincides with the target vehicle body slip angle at the time of closest proximity.