METHOD AND SYSTEM FOR ADAPTIVELY COMPENSATING CLOSED-LOOP FRONT-WHEEL STEERING CONTROL

• US 20090319130A1
• Filed: 08/25/2009
• Published: 12/24/2009
• Est. Priority Date: 03/10/2006
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations Incorporated (General Motors Company)
• Inventors: Shin, Kwang-Keun, Chen, Shih-Ken
• Granted Patent: US 7,809,484 B2
• Time in Patent Office: Days
• US Class Current: 701/42
• CPC Class Codes: B62D 6/007 adjustable by the driver, e.g. sport mode

Abstract

An active front-wheel vehicle steering control system that employs closed-loop control includes an adaptive compensation sub-system that compensates for changes in vehicle dynamic parameters. The control system includes a dynamic parameter estimation sub-system that provides an estimated front cornering compliance and rear cornering compliance based on a steering wheel angle signal, a vehicle lateral acceleration signal, a vehicle yaw rate signal and a vehicle speed signal. The closed-loop control includes active gain for each of vehicle yaw rate, yaw acceleration, side-slip and side-slip rate, all based on the vehicle speed and vehicle dynamic parameter changes for use in generating a steering angle control signal to the front wheels of the vehicle.

Claims

1. A method for active front wheel steering control for a vehicle having steerable front wheels and fixed rear wheels, comprising:

generating a steering wheel angle signal corresponding to a steering wheel angle;

controlling the steerable front wheels based upon a steering control signal comprising a combination of an open-loop steering control signal and a closed-loop steering control signal;

estimating vehicle dynamics parameters based upon signal inputs from vehicle sensors;

providing the open-loop steering control signal corresponding to the steering wheel angle signal;

providing the closed-loop steering control signal based upon the estimated vehicle dynamics parameters;

providing an original yaw rate feedback angle signal; and

providing a corrected yaw rate feedback angle signal based on the estimated vehicle dynamics parameters;

wherein the corrected yaw rate feedback angle signal is provided in accordance with the relationship;

2. The method according to claim 1 wherein the signal inputs from vehicle sensors comprise a steering wheel angle signal, a vehicle lateral acceleration signal, a vehicle yaw rate signal and a vehicle speed signal.

3. A method for active front wheel steering control for a vehicle having steerable front wheels and fixed rear wheels, comprising:

generating a steering wheel angle signal corresponding to a steering wheel angle;

controlling the steerable front wheels based upon a steering control signal comprising a combination of an open-loop steering control signal and a closed-loop steering control signal;

estimating vehicle dynamics parameters based upon signal inputs from vehicle sensors;

providing the open-loop steering control signal corresponding to the steering wheel angle signal;

providing the closed-loop steering control signal based upon the estimated vehicle dynamics parameters;

providing an original yaw acceleration feedback angle signal;

providing a corrected yaw acceleration feedback angle signal based on the estimated vehicle dynamics parameters;

wherein the corrected yaw acceleration feedback angle is provided in accordance with the relationship;

4. The method according to claim 3 wherein the signal inputs from vehicle sensors comprise a steering wheel angle signal, a vehicle lateral acceleration signal, a vehicle yaw rate signal and a vehicle speed signal.

5. A method for active front wheel steering control for a vehicle having steerable front wheels and fixed rear wheels, comprising:

generating a steering wheel angle signal corresponding to a steering wheel angle;

controlling the steerable front wheels based upon a steering control signal comprising a combination of an open-loop steering control signal and a closed-loop steering control signal;

estimating vehicle dynamics parameters based upon signal inputs from vehicle sensors;

providing the open-loop steering control signal corresponding to the steering wheel angle signal;

providing the closed-loop steering control signal based upon the estimated vehicle dynamics parameters;

providing an original side-slip feedback angle signal;

providing a corrected side-slip feedback angle signal based on the estimated vehicle dynamics parameters;

wherein the corrected side-slip feedback angle signal is provided in accordance with the relationship;

6. The method according to claim 5 wherein the signal inputs from vehicle sensors comprise a steering wheel angle signal, a vehicle lateral acceleration signal, a vehicle yaw rate signal and a vehicle speed signal.

7. A method for active front wheel steering control for a vehicle having steerable front wheels and fixed rear wheels, comprising:

generating a steering wheel angle signal corresponding to a steering wheel angle;

controlling the steerable front wheels based upon a steering control signal comprising a combination of an open-loop steering control signal and a closed-loop steering control signal;

estimating vehicle dynamics parameters based upon signal inputs from vehicle sensors;

providing the open-loop steering control signal corresponding to the steering wheel angle signal;

providing the closed-loop steering control signal based upon the estimated vehicle dynamics parameters;

providing an original side-slip rate feedback angle signal;

providing a corrected side-slip rate feedback angle signal based on the estimated vehicle dynamics parameters;

wherein the corrected side-slip rate feedback angle is provided in accordance with the relationship;

8. The method according to claim 7 wherein the signal inputs from vehicle sensors comprise a steering wheel angle signal, a vehicle lateral acceleration signal, a vehicle yaw rate signal and a vehicle speed signal.