Method and system for adaptively compensating closed-loop front-wheel steering control

• US 7,599,774 B2
• Filed: 03/10/2006
• Issued: 10/06/2009
• 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 (Motors Liquidation Co. GUC Trust)
• Inventors: Shin, Kwang-Keun, Chen, Shih-Ken
• Primary Examiner(s): Hellner; Mark
• Assistant Examiner(s): Algahaim; Helal A
• Application Number:
  US11/372,808
• Publication Number:
  US 20070213902A1
• Time in Patent Office: 1,306 Days
• Field of Search: 701 41- 43, 280/400, 280/419, 280/426, 280/442, 180418-420, 180443-446
• 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. An active front wheel steering control system for a vehicle having steerable front wheels and fixed rear wheels, comprising:

a vehicle steering wheel configured to generate a steering wheel angle signal corresponding to a steering wheel angle;

a steering actuator configured to control 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;

a real-time vehicle dynamics estimation subsystem configured to estimate vehicle dynamics parameters based upon signal inputs from vehicle sensors;

an open-loop control subsystem configured to provide the open-loop steering control signal corresponding to the steering wheel angle signal;

a closed-loop control subsystem configured to provide the closed-loop steering control signal based upon the estimated vehicle dynamics parameters;

a yaw rate feedback look-up table configured to provide an original yaw rate feedback angle signal; and

a yaw rate feedback adaptive compensation sub-system configured to provide a corrected yaw rate feedback angle signal based on the estimated vehicle dynamics parameters;

wherein the yaw rate feedback adaptive compensation sub-system is configured to provide the corrected yaw rate feedback angle signal in accordance with the relationship;

2. The system 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. An active front wheel steering control system for a vehicle having steerable front wheels and fixed rear wheels, comprising:

a vehicle steering wheel configured to generate a steering wheel angle signal corresponding to a steering wheel angle;

a steering actuator configured to control 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;

a real-time vehicle dynamics estimation subsystem configured to estimate vehicle dynamics parameters based upon signal inputs from vehicle sensors;

an open-loop control subsystem configured to provide the open-loop steering control signal corresponding to the steering wheel angle signal;

a closed-loop control subsystem configured to provide the closed-loop steering control signal based upon the estimated vehicle dynamics parameters;

a yaw acceleration feedback look-up table configured to provide an original yaw acceleration feedback angle signal;

a yaw acceleration feedback adaptive compensation sub-system configured to provide a corrected yaw acceleration feedback angle signal based on the estimated vehicle dynamics parameters;

wherein the yaw acceleration feedback adaptive compensation sub-system is configured to provide the corrected yaw acceleration feedback angle in accordance with the relationship;

4. The system 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. An active front wheel steering control system for a vehicle having steerable front wheels and fixed rear wheels, comprising:

a vehicle steering wheel configured to generate a steering wheel angle signal corresponding to a steering wheel angle;

a steering actuator configured to control 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;

a real-time vehicle dynamics estimation subsystem configured to estimate vehicle dynamics parameters based upon signal inputs from vehicle sensors;

an open-loop control subsystem configured to provide the open-loop steering control signal corresponding to the steering wheel angle signal;

a closed-loop control subsystem configured to provide the closed-loop steering control signal based upon the estimated vehicle dynamics parameters;

a side-slip feedback look-up table configured to provide an original side-slip feedback angle signal;

a side-slip feedback adaptive compensation sub-system configured to provide a corrected side-slip feedback angle signal based on the estimated vehicle dynamics parameters;

wherein the side-slip feedback adaptive compensation sub-system is configured to provide the corrected side-slip feedback angle signal in accordance with the relationship;

6. The system 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. An active front wheel steering control system for a vehicle having steerable front wheels and fixed rear wheels, comprising:

a vehicle steering wheel configured to generate a steering wheel angle signal corresponding to a steering wheel angle;

a steering actuator configured to control 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;

a real-time vehicle dynamics estimation subsystem configured to estimate vehicle dynamics parameters based upon signal inputs from vehicle sensors;

an open-loop control subsystem configured to provide the open-loop steering control signal corresponding to the steering wheel angle signal;

a closed-loop control subsystem configured to provide the closed-loop steering control signal based upon the estimated vehicle dynamics parameters;

a side-slip rate feedback look-up table configured to provide an original side-slip rate feedback angle signal;

a side-slip rate feedback adaptive compensation sub-system configured to provide a corrected side-slip rate feedback angle signal based on the estimated vehicle dynamics parameters;

wherein the side-slip rate feedback adaptive compensation sub-system is configured to provide the corrected side-slip rate feedback angle in accordance with the relationship;

8. The system 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.