Vehicle-trailer stability and handling performance improvement using rear-wheel steering control

• US 7,640,089 B2
• Filed: 04/06/2005
• Issued: 12/29/2009
• Est. Priority Date: 04/06/2005
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations Incorporated (Motors Liquidation Co. GUC Trust)
• Inventors: Chin, Yuen-Kwok, Lee, Yong H., Deng, Weiwen, Rule, David S.
• Primary Examiner(s): Camby; Richard M.
• Application Number:
  US11/100,016
• Publication Number:
  US 20060229782A1
• Time in Patent Office: 1,728 Days
• Field of Search: 701 41- 43, 180441-446
• US Class Current: 701/42
• CPC Class Codes: B62D 13/00 Steering specially adapted for trailers combined traction and steering hitches B60D
• CPC Class Codes: B62D 6/003 in order to control vehicle yaw movement, i.e. around a vertical axis B62D6/007 takes precedence
• CPC Class Codes: B62D 7/159 characterised by computing methods or stabilisation processes or systems, e.g. responding to yaw rate, lateral wind, load, road condition

Abstract

A vehicle steering control system for a vehicle/trailer combination that provides rear-wheel steering assist to improve the vehicle/trailer combination stability and handling performance. The control system provides an open-loop feed-forward control signal based on hand-wheel angle and vehicle speed. The control system includes a vehicle yaw rate command interpreter that provides a vehicle closed-loop feedback control signal based on the yaw rate of the vehicle, a trailer yaw rate command interpreter that provides a trailer closed-loop feedback control signal based on the yaw rate of the trailer, and a vehicle lateral acceleration command interpreter that provides a closed-loop feedback control signal based on the lateral acceleration of the vehicle. The closed-loop feedback signals are added together and then combined with the open-loop feed-forward control signal to provide the rear-wheel steering assist.

Claims

1. A control system for providing a rear-wheel steering assist signal for rear wheels on a vehicle, said system comprising:

a hand-wheel sensor for providing a hand-wheel angle signal of the position of a vehicle hand-wheel;

a vehicle speed sensor for providing a vehicle speed signal of the speed of the vehicle;

a vehicle yaw rate sensor for providing a measured vehicle yaw rate signal of the yaw rate of the vehicle;

a vehicle yaw rate command interpreter responsive to the hand-wheel angle signal and the vehicle speed signal, said vehicle yaw rate command interpreter generating a vehicle yaw rate command signal;

a differencer responsive to the vehicle yaw rate command signal and the measured vehicle yaw rate signal, said differencer generating a vehicle yaw rate error signal; and

a vehicle yaw rate feedback controller responsive to the vehicle yaw rate error signal, said vehicle yaw rate feedback controller generating a vehicle yaw rate feedback signal for the rear-wheel steering assist signal.

2. The system according to claim 1 wherein the vehicle yaw rate feedback controller is a proportional-integral-derivative (PID) controller.

3. The system according to claim 1 wherein the system attempts to maintain a zero side-slip at a hitch point between the vehicle and a trailer.

4. The system according to claim 1 wherein vehicle yaw rate command interpreter derives a vehicle un-damped natural frequency and vehicle damping ratio from a second-order model.

5. The system according to claim 1 wherein the vehicle yaw rate command interpreter generates a vehicle steady-state signal used for calculating the vehicle yaw rate command signal.

6. The system according to claim 5 wherein the vehicle yaw rate command interpreter includes a second-order filter that is responsive to the vehicle steady-state signal, a vehicle un-damped natural frequency and a vehicle damping ratio that are used for calculating the vehicle yaw rate command signal.