Vehicle-trailer low-speed offtracking control

• US 20070152424A1
• Filed: 12/20/2005
• Published: 07/05/2007
• Est. Priority Date: 12/20/2005
• Status: Abandoned Application

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations LLC (General Motors Company)
• Inventors: Lee, Yong, Deng, Weiwen, Tian, Ming
• Application Number:
  US11/313,164
• Publication Number:
  US 20070152424A1
• Time in Patent Office: Days
• US Class Current: 280/432
• CPC Class Codes: B62D 13/00 Steering specially adapted for trailers combined traction and steering hitches B60D
• CPC Class Codes: B62D 53/005 Combinations with at least three axles and comprising two or more articulated parts articulated buses B62D47/025
• 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

An offtracking control system for a vehicle/trailer combination that properly steers the rear wheels of the vehicle to control the hitch angle between the vehicle and the trailer to prevent trailer offtracking. The control system generates a desired hitch angle and a time delay between the front wheels of the vehicle and the rear wheels of the trailer. A delay unit generates a hitch angle command from the desired hitch angle and the time delay. The hitch angle command is subtracted from a measured hitch angle to generate a hitch angle error signal. The hitch angle error signal is sent to a feedback controller that generates a closed-loop rear-wheel steering signal. The closed-loop rear-wheel steering signal is added to an open-loop rear-wheel steering signal to generate a rear-wheel steering command signal that prevents trailer offtracking.

Claims

1. A control system for preventing offtracking of a trailer being towed by a vehicle, said system comprising:

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

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

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

a hitch angle sensor for providing a signal of the measured hitch angle between the vehicle and the trailer;

a desired hitch angle sub-system responsive to the vehicle speed signal, the vehicle yaw rate signal, the hand-wheel angle signal and the measured hitch angle signal, said hitch angle sub-system generating a desired hitch angle signal;

a variable time delay sub-system responsive to the vehicle speed signal, the vehicle yaw rate signal, the hand-wheel angle signal and the hitch angle signal, said variable time delay sub-system generating a time delay signal between front wheels of the vehicle and rear wheels of the trailer;

a hitch angle command sub-system responsive to the desired hitch angle signal and the time delay signal, said hitch angle command sub-system generating a hitch angle command;

a differencer responsive to the hitch angle command and the measured hitch angle signal, said difference generating a hitch angle error signal; and

a controller responsive to the error signal, said controller generating a closed-loop rear-wheel steering signal.

2. The system according to claim 1 further comprising an adder, said adder being responsive to the closed-loop rear-wheel steering signal and an open-loop rear-wheel steering signal, said adder generating a rear-wheel steering command signal for steering rear wheels of the vehicle that prevents the offtracking.

3. The system according to claim 1 wherein the controller is a proportional-integral-derivative (PID) controller.

4. The system according to claim 1 wherein the system only prevents trailer offtracking for vehicle speeds less than a predetermined vehicle speed.

5. The system according to claim 4 wherein the predetermined vehicle speed is about 40 kph.

6. A control system for preventing offtracking of a trailer being towed by a vehicle, said system comprising:

a desired hitch angle sub-system for generating a desired hitch angle signal;

a variable time delay sub-system for generating a time delay signal between the vehicle and the trailer; and

a hitch angle command sub-system responsive to the desired hitch angle signal and the time delay signal, said hitch angle command sub-system generating a hitch angle command that is used to prevent the trailer offtracking.

7. The system according to claim 6 further comprising a vehicle speed sensor for providing a signal of the speed of the vehicle, a vehicle yaw rate sensor for providing a signal of the yaw rate of the vehicle, a hand-wheel angle sensor for providing a signal of the angle of a vehicle hand-wheel, and a hitch angle sensor for providing a signal of the measured hitch angle between the vehicle and the trailer, wherein the desired hitch angle sub-system and the variable time delay sub-system are responsive to the vehicle speed signal, the vehicle yaw rate signal, the hand-wheel angle signal and the measured hitch angle signal.

8. The system according to claim 6 further comprising a differencer responsive to the hitch angle command and the measured hitch angle signal, said difference generating a hitch angle error signal.

9. The system according to claim 8 further comprising a controller responsive to the error signal, said controller generating a closed-loop rear-wheel steering signal.

10. The system according to claim 9 further comprising an adder, said adder being responsive to the closed-loop rear-wheel steering signal and an open-loop rear-wheel steering signal, said adder generating a rear-wheel steering command signal for steering rear wheels of the vehicle that prevents the offtracking.

11. The system according to claim 9 wherein the controller is a proportional-integral-derivative (PI D) controller.

12. The system according to claim 6 wherein the system only prevents trailer offtracking for vehicle speeds less than a predetermined speed.

13. The system according to claim 6 wherein the time delay sub-system generates the time delay signal between front wheels of the vehicle and rear wheels of the trailer.

14. A method for preventing offtracking of a trailer being towed by a vehicle, said method comprising:

generating a desired hitch angle signal;

generating a time delay signal between the vehicle and the trailer; and

generating a hitch angle command from the desired hitch angle signal and the time delay signal that is used to prevent the trailer offtracking.

15. The method according to claim 14 wherein generating a desired hitch angle signal and generating a time delay signal between the vehicle and the trailer includes using a measured vehicle speed, a measured vehicle yaw rate, a measured hand-wheel angle and a measured hitch angle.

16. The method according to claim 14 further comprising generating a hitch angle error signal between the hitch angle command and a measured hitch angle.

17. The method according to claim 16 further comprising generating a closed-loop rear-wheel steering signal from the error signal.

18. The method according to claim 17 further comprising generating a rear-wheel steering command signal for steering rear wheels of the vehicle that prevents the offtracking by adding the closed-loop rear-wheel steering signal and an open-loop rear-wheel steering signal.

19. The method according to claim 14 wherein the method only prevents trailer offtracking for vehicle speeds less than a predetermined speed.

20. The method according to claim 14 wherein generating a time delay signal between the vehicle and the trailer includes generating the time delay signal between front wheels of the vehicle and rear wheels of the trailer.