Vehicle lateral control system

• US 7,706,945 B2
• Filed: 08/13/2007
• Issued: 04/27/2010
• Est. Priority Date: 09/07/2005
• 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: Lee, Yong H., Deng, Weiwen
• Primary Examiner(s): Tran; Khoi
• Assistant Examiner(s): Peche; Jorge O
• Application Number:
  US11/838,032
• Publication Number:
  US 20080195280A1
• Time in Patent Office: 988 Days
• Field of Search: 701/71, 701/91, 701/93, 701/48, 701/36, 701/38, 701/41, 701/69, 701/23, 701/25, 701/70, 701/82, 701/83, 701/91.93, 180/197, 180/117, 180/119, 180/408, 180/445, 303/139, 303/146
• US Class Current: 701/41
• CPC Class Codes: B60T 2220/02 Driver type; Driving style; Driver adaptive features
• CPC Class Codes: B60T 2230/02 Side slip angle, attitude angle, floating angle, drift angle
• CPC Class Codes: B60T 2260/08 Coordination of integrated systems
• CPC Class Codes: B60T 2270/86 Optimizing braking by using ESP vehicle or tire model
• CPC Class Codes: B60T 8/1755 Brake regulation specially adapted to control the stability of the vehicle, e.g. taking into account yaw rate or transverse acceleration in a curve road vehicle drive control systems for control of driving stability otherwise than by controlling a particular sub-unit B60W30/02

Abstract

A vehicle lateral control system that integrates both vehicle dynamics and kinematics control. The system includes a driver interpreter that provides desired vehicle dynamics and predicted vehicle path based on driver input. Error signals between the desired vehicle dynamics and measured vehicle dynamics, and between the predicted vehicle path and the measured vehicle target path are sent to dynamics and kinematics control processors for generating a separate dynamics and kinematics command signals, respectively, to minimize the errors. The command signals are integrated by a control integration processor to combine the commands to optimize the performance of stabilizing the vehicle and tracking the path. The integrated command signal can be used to control one or more of front wheel assist steering, rear-wheel assist steering or differential braking.

Claims

1. A vehicle lateral control system for a vehicle, said system comprising:

a driver steering intent sensor for providing a driver steering intent signal;

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

a lateral acceleration sensor for providing a measured lateral acceleration signal of the lateral acceleration of the vehicle;

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

a target path sub-system for providing a target path signal indicative of a path of the vehicle;

a command interpreter processor responsive to the driver steering intent signal and generating a desired yaw rate signal or a desired side-slip signal;

a first subtractor responsive to the desired yaw signal and the measured yaw rate signal or the desired side-slip signal and a side-slip estimation signal, said first subtractor generating a dynamical error signal;

a motion/path prediction processor responsive to the driver steering intent signal and generating a predicted path signal of the predicted path of the vehicle;

a second subtractor responsive to the predicted path signal and the target path signal, and generating a kinematical error signal;

a dynamics control processor responsive to the dynamical error signal and generating a dynamics control command signal;

a kinematics control processor responsive to the kinematical error signal and generating a kinematics control command signal; and

a control integration processor responsive to the dynamics control command signal and the kinematics control command signal, said control integration processor integrating the dynamics control command signal and the kinematics control command signal into an integrated control command signal, wherein the integrated control command signal can be used to control front-wheel assist steering, rear-wheel assist steering and/or differential braking.

2. The system according to claim 1 wherein the command interpreter processor employs a two-degree of freedom bicycle model using a high coefficient of friction road surface to generate the desired yaw rate signal or the desired side-slip signal.

3. The system according to claim 1 wherein the motion/path prediction processor includes a vehicle dynamics estimation processor and a vehicle kinematics estimation processor, said vehicle dynamics estimation processor generating a vehicle state variable signal based on vehicle lateral velocity and vehicle yaw rate, and said vehicle kinematics estimation processor generating the predicted path signal based on the vehicle state variable signals.

4. The system according to claim 3 wherein the vehicle dynamics estimation processor employs a bicycle model and state feedback to generate the state variable signals.

5. The system according to claim 1 wherein the dynamics control processor employs proportional-integral-derivative control.

6. The system according to claim 1 wherein the kinematics control processor employs an optimal control process that minimizes a predefined cost function.

7. The system according to claim 1 wherein the driver steering intent sensor is a hand-wheel angle sensor.

8. The system according to claim 1 further comprising an actuator responsive to the integrated command signal from the control integration processor.

9. The system according to claim 8 wherein the actuator is selected from the group consisting of a front-wheel steering assist actuator, a rear-wheel steering assist actuator and/or a differential braking control actuator.

10. The system according to claim 1 wherein the target path sub-system is selected from the group consisting of a vision sub-system, a radar sub-system and a map sub-system with a GPS sensor.

11. The system according to claim 1 wherein the control integration processor transforms a slow data rate coordinate frame to a fast data rate coordinate frame.

12. A vehicle lateral control system for a vehicle, said system comprising:

a hand-wheel angle sensor for providing a driver steering intent signal;

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

a lateral acceleration sensor for providing a measured lateral acceleration signal of the lateral acceleration of the vehicle;

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

a target path sub-system for providing a target path signal indicative of a path of the vehicle;

a command interpreter processor responsive to the driver steering intent signal and generating a desired yaw rate signal or desired side-slip signal;

a first subtractor responsive to the desired yaw rate signal and the measured yaw rate signal or the desired side-slip signal and a side-slip estimation signal, and generating a dynamical error signal;

a motion/path prediction processor responsive to the driver steering intent signal and generating a predicted path signal of the predicted path of the vehicle, said motion/path prediction processor including a vehicle dynamics estimation processor and a vehicle kinematics estimation processor, said vehicle dynamic estimation processor generating a vehicle state variable signal based on vehicle lateral velocity and vehicle yaw rate, and said vehicle kinematics estimation processor generating the predicted path signal based on the vehicle state variable signal;

a second subtractor responsive to the predicted path signal and the target path signal, and generating a kinematical error signal;

a dynamics control processor responsive to the dynamical error signal and generating a dynamics control command signal;

a kinematics control processor responsive to the kinematical error signal and generating a kinematics control command signal;

a control integration processor responsive to the dynamics control command signal and the kinematics control command signal, said control integration processor integrating in the dynamics control command signal and the kinematics control command signal into an integrated control command signal; and

an actuator responsive to the integrated command signal from the control integration processor for controlling the vehicle, wherein the integrated control command signal can be used to control front-wheel assist steering, rear-wheel assist steering and/or differential braking.

13. The system according to claim 12 wherein the command interpreter processor employs a two-degree of freedom bicycle model using a high coefficient of friction road surface to generate the desired yaw rate signal or the desired side-slip signal.

14. The system according to claim 12 wherein the kinematics control processor employs an optimal control process that minimizes a predefined cost function.

15. The system according to claim 12 wherein the actuator is selected from the group consisting of a front-wheel steering assist actuator, a rear-wheel steering assist actuator and a differential braking control actuator.

16. The system according to claim 12 wherein the target path sub-system is selected from the group consisting of a vision sub-system, a radar sub-system and a map sub-system with a GPS sensor.