Granted Patent B2

US 7,154,385 · App. 10/987,556 · Granted Dec 26, 2006

Abstract

Claims (38)

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.

Assignments (12)