Vehicle-trailer backing up system using active front steer

• US 7,154,385 B2
• Filed: 11/12/2004
• Issued: 12/26/2006
• Est. Priority Date: 11/12/2004
• Status: Expired due to Fees

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: General Motors Corporation (Motors Liquidation Co. GUC Trust)
• Inventors: Chin, Yuen-Kwok, Lin, William C., Lee, Yong H., Deng, Weiwen
• Primary Examiner(s): Hofsass, Jeffery
• Assistant Examiner(s): Labbees, Edny
• Application Number:
  US10/987,556
• Publication Number:
  US 20060103511A1
• Time in Patent Office: 774 Days
• Field of Search: 340/431, 340/671, 340/684, 340/691.5, 340/691.8, 340/435, 701/36, 701/41
• US Class Current: 340/431
• CPC Class Codes: B62D 13/06 for backing a normally drawn trailer
• CPC Class Codes: B62D 15/027 Parking aids, e.g. instruction means
• CPC Class Codes: B62D 5/008 Changing the transfer ratio between the steering wheel and the steering gear by variable supply of energy, e.g. by using a superposition gear
• CPC Class Codes: B62D 6/002 computing target steering angles for front or rear wheels B62D7/159 takes precedence

Abstract

A vehicle-trailer back-up control system that employs an active front steer sub-system. The system includes a smart hitch controller that receives a vehicle speed signal and a hand-wheel angle signal, and calculates a hitch angle command signal. The system further includes a hitch angle sensor that measures the hitch angle between the vehicle and the trailer that is compared to the hitch angle command signal to generate a hitch angle error signal. A PID control unit receives the hitch angle error signal, and generates a corrected road wheel angle signal based on proportional and derivative gains. The corrected road wheel angle signal is used to generate a motor angle signal that is applied to a steering actuator to be combined with the steering angle signal to generate the front wheel steering signal during a back-up maneuver.

Claims

1. A method for providing active front steering for a vehicle and trailer combination during a back-up maneuver, said method comprising:

determining a steering wheel angle signal indicative of a steering hand-wheel of the vehicle;

determining a vehicle speed signal indicative of the speed of the vehicle;

using the steering wheel angle signal and the vehicle speed signal to calculate a hitch angle command signal;

measuring an actual hitch angle between the vehicle and the trailer and providing a measured hitch angle signal;

comparing the hitch angle command signal to the measured hitch angle signal to provide an error signal;

determining a corrected front road wheel angle signal based on the error signal and the vehicle speed signal;

using the corrected road wheel angle signal to generate an actuator angle signal; and

using the actuator angle signal and the steering wheel angle signal to control an active front wheel steering actuator to steer the vehicle-trailer combination during the back-up maneuver.

2. The method according to claim 1 wherein controlling the front wheel steering actuator includes controlling an electric motor.

3. The method according to claim 1 wherein determining the corrected road wheel angle signal includes using a PID control unit.

4. The method according to claim 1 wherein using the steering wheel angle signal and the vehicle speed signal to calculate a hitch angle command signal includes employing a bicycle model to calculate the hitch angle command signal.

5. The method according to claim 1 wherein using the steering wheel angle and the vehicle speed signal to calculate a hitch angle command signal includes employing a kinematics model to calculate the hitch angle command signal.

6. The method according to claim 1 wherein the steering hand-wheel is decoupled from a steering gear of the vehicle to provide counter steering.

7. The method according to claim 1 further comprising determining whether a switch has been activated and the vehicle is in a reverse gear before using the actuator angle signal and the steering wheel angle signal to steer the vehicle.

8. A system for providing active front steering for a vehicle and trailer combination during a back-up maneuver, said system comprising:

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

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

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

a command interpreter responsive to the steering wheel angle signal and the vehicle speed signal, said command interpreter calculating a hitch angle command signal;

a comparator responsive to the hitch angle command signal and the measured hitch angle signal, said comparator providing an error signal;

a control unit responsive to the error signal and the vehicle speed signal, said control unit determining a corrected front road wheel angle signal;

a generator responsive to the corrected road wheel angle signal, said generator generating an actuator angle signal; and

an active front steering actuator responsive to the actuator angle signal and the steering wheel angle signal, said active front steering actuator providing a steering signal for steering the vehicle-trailer combination during the back-up maneuver.

9. The system according to claim 8 wherein the front steering actuator includes an electric motor.

10. The system according to claim 8 wherein the control unit is a PID control unit.

11. The system according to claim 8 wherein the command interpreter employs a bicycle model to calculate the hitch angle command signal.

12. The system according to claim 8 wherein the command interpreter employs a kinematics model to calculate the hitch angle command signal.

13. The system according to claim 8 wherein the steering hand-wheel is decoupled from a steering gear of the vehicle to provide counter steering.

14. The system according to claim 8 further comprising a switch for activating and deactivating the system.

15. A system for providing active front steering for a vehicle and trailer combination during a back-up maneuver, said system comprising:

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

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

an active front steering sub-system that uses the steering wheel angle signal and the measured hitch angle signal for providing an active steering signal for steering the vehicle-trailer combination during the back-up maneuver.

16. The system according to claim 15 wherein the active front steering sub-system employs a bicycle model or a kinematics model to calculate a hitch angle command signal that is compared to the measured hitch angle signal.

17. The system according to claim 15 wherein the front steering sub-system includes an electric motor for providing an active steering angle signal.

18. The system according to claim 15 wherein the front steering sub-system employs a PID control unit.

19. The system according to claim 15 wherein the steering hand-wheel is decoupled from a steering gear of the vehicle to provide counter steering.