MODEL BASED PREDICTIVE CONTROL FOR AUTOMATED LANE CENTERING/CHANGING CONTROL SYSTEMS

• US 20100228420A1
• Filed: 03/06/2009
• Published: 09/09/2010
• Est. Priority Date: 03/06/2009
• 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, Jin-Woo
• Granted Patent: US 8,190,330 B2
• Time in Patent Office: Days
• US Class Current: 701/26
• CPC Class Codes: B62D 1/28 non-mechanical , e.g. following a line or other known markers
• CPC Class Codes: B62D 15/0255 Automatic changing of lane, e.g. for passing another vehicle

Abstract

A system and method for providing steering control for lane changing and lane centering purposes in an autonomous or semi-autonomous vehicle system. A vehicle vision system calculates roadway lane marking information, such as lateral offset, yaw angle and roadway curvature with respect to the vehicle'"'"'s centered coordinate system. The roadway is then modeled as a second order polynomial equation. The method then predicts roadway lateral position and yaw angle over a pre-defined lane change completion time using a vehicle dynamic model. The method then compares a predicted vehicle path with a desired vehicle path to generate an error value, and calculates a steering angle command to minimize the error value, where the steering angle command is calculated as a function of vehicle lateral position, vehicle lateral speed, vehicle yaw rate and vehicle yaw angle. The steering angle command is then sent to the vehicle steering system.

Claims

1. A method for providing vehicle steering control in an autonomous or semi-autonomous vehicle driving system, said method comprising:

determining roadway lane marking information of a roadway on which the vehicle is traveling;

modeling the roadway using the roadway lane marking information;

predicting a vehicle path using the roadway model;

providing a desired vehicle path;

comparing the predicted vehicle path and the desired vehicle path to generate a path error value; and

generating a steering angle command based on the path error value where the steering angle command is a function of vehicle lateral position, vehicle lateral speed, vehicle yaw rate and vehicle yaw angle.

2. The method according to claim 1 wherein modeling the roadway includes modeling the roadway as a second order polynomial equation.

3. The method according to claim 1 wherein determining roadway lane marking information includes determining vehicle lateral position, roadway curvature and vehicle yaw angle.

4. The method according claim 1 wherein predicting the vehicle path using the roadway model includes predicting the roadway lateral position and vehicle yaw angle.

5. The method according to claim 4 wherein predicting the roadway lateral position and the vehicle yaw angle includes using the equation:

6. The method according to claim 1 wherein providing the desired vehicle path includes providing the desired vehicle path using a roadway lateral offset of the vehicle and a vehicle heading angle.

7. The method according to claim 6 wherein providing a desired vehicle path includes generating a fifth order polynomial path based on the equation:

y_d(t)=a₅x_d⁵(t)+a₄x_d⁴(t)+a₃x_d³(t)+a₂x_d²(t)+a₁x_d¹(t)+a₀

where y is the lateral offset.

8. The method according to claim 1 wherein providing a steering angle command includes providing a steering angle command defined by the equation:

9. A method for providing vehicle steering control in an autonomous or semi-autonomous vehicle driving system, said method comprising:

determining roadway lane marking information of a roadway on which the vehicle is traveling including determining vehicle lateral position, roadway curvature and vehicle yaw angle;

modeling the roadway as a second order polynomial equation using the roadway lane marking information;

predicting a vehicle path using the roadway model including predicting a roadway lateral offset and a vehicle yaw angle;

providing a desired vehicle path;

comparing the predicted vehicle path and the desired vehicle path to generate a path error value; and

generating a steering angle command based on the path error value, wherein providing a steering angle command includes providing a steering angle command defined by the equation;

10. The method according to claim 9 wherein predicting a roadway lateral position and vehicle yaw angle includes using the equation:

11. The method according to claim 9 wherein determining a desired vehicle path includes generating a fifth order polynomial path based on the equation:

y_d(t)=a₅x_d⁵(t)+a₄x_d⁴(t)+a₃x_d³(t)+a₂x_d²(t)+a₁x_d¹(t)+a₀

where y is the lateral offset.

12. A system for providing vehicle steering control in an autonomous or semi-autonomous vehicle driving system, said system comprising:

means for determining roadway lane marking information of a roadway on which the vehicle is traveling;

means for modeling the roadway using the roadway lane marking information;

means for predicting a vehicle path using the roadway model;

means for providing a desired vehicle path;

means for comparing the predicted vehicle path and the desired vehicle path to generate a path error value; and

means for generating a steering angle command based on the path error value where the steering angle command is a function of vehicle lateral position, vehicle lateral speed, vehicle yaw rate and vehicle yaw angle.

13. The system according to claim 12 wherein the means for modeling the roadway models the roadway as a second order polynomial equation.

14. The system according to claim 12 wherein the means for determining roadway lane marking information determines vehicle lateral position, roadway curvature and vehicle yaw angle.

15. The system according to claim 12 wherein the means for predicting the vehicle path predicts a roadway lateral position and a vehicle yaw angle over a predetermined steering completion time.

16. The system according to claim 15 wherein the means for predicting the roadway lateral position and the vehicle yaw angle uses the equation:

17. The system according to claim 12 wherein the means for providing the desired vehicle path provides the desired vehicle path using a roadway lateral offset of the vehicle and a vehicle heading angle.

18. The system according to claim 12 wherein the means for determining a desired vehicle path includes generating a fifth order polynomial path based on the equation:

y_d(t)=a₅x_d⁵(t)+a₄x_d⁴(t)+a₃x_d³(t)+a₂x_d²(t)+a₁x_d¹(t)+a₀

where y is the lateral offset.

19. The system according to claim 12 wherein the means for providing a steering angle command provides a steering angle command defined by the equation: