Vehicle steering control method and performance

• US 7,769,512 B2
• Filed: 02/12/2007
• Issued: 08/03/2010
• Est. Priority Date: 02/12/2007
• Status: Active Grant

• Current Assignee: Deere & Company
• Original Assignee: Deere & Company
• Inventors: Norris, William Robert, Reid, John Franklin, Gilmore, Brian Joseph, Romig, Bernard Edwin
• Primary Examiner(s): Beaulieu; Yonel
• Application Number:
  US11/673,644
• Publication Number:
  US 20080195281A1
• Time in Patent Office: 1,268 Days
• Field of Search: 701/41, 701/44, 701/27, 180/6.2, 700/50, 706/9
• US Class Current: 701/44
• CPC Class Codes: B60W 2050/0014 Adaptive controllers
• CPC Class Codes: B60W 2050/0057 Frequency analysis, spectral techniques or transforms
• CPC Class Codes: B60W 40/09 Driving style or behaviour
• CPC Class Codes: B60W 40/105 Speed
• CPC Class Codes: B62D 6/007 adjustable by the driver, e.g. sport mode
• CPC Class Codes: G05B 13/0275 using fuzzy logic only

Abstract

A vehicle steering control method including the steps of obtaining a heading error, obtaining a velocity value, obtaining a distance error, applying the heading error, inputting a measure of operator aggressiveness and defuzzifying an output from a steering rule base. The velocity value and the distance error are applied along with the heading error to fuzzy logic membership functions to produce an output that is applied to a steering rule base. A measure of the operator aggressiveness is input to the steering rule base. An output from the steering rule base is defuzzified to produce a steering signal.

Claims

1. A vehicle steering control method, comprising the steps of:

obtaining a heading error;

obtaining a velocity value;

obtaining a distance error;

applying said heading error, said velocity value and said distance error to fuzzy logic membership functions to produce an output that is applied to a steering rule base;

inputting a measure of operator aggressiveness to said steering rule base;

defuzzifying an output from said steering rule base to produce a steering signal;

receiving said steering signal by a vehicle control unit; and

steering a vehicle by said vehicle control unit using said steering signal.

2. The method of claim 1, further comprising the step of inputting an operator reaction time to said vehicle control unit.

3. The method of claim 1, further comprising the step of generating at least one of said heading error, said velocity value and said distance error by comparing a required path to a current position of the vehicle.

4. The method of claim 3, further comprising the step of using operator experience/perception information by said fuzzy logic membership functions.

5. The method of claim 1, further comprising the step of establishing a required path which serves as an input to said obtaining a distance error step.

6. The method of claim 5, wherein said establishing a required path step also serves as an input to said obtaining a velocity value step.

7. The method of claim 5, further comprising the step of using feedback information to establish a current position of the vehicle as an input to said obtaining a distance error step.

8. The method of claim 7, wherein said using feedback information step also serves as an input to said obtaining a velocity value step.

9. The method of claim 8, further comprising the step of obtaining at least one of an orientation, a location and a velocity to input to at least one of said obtaining a velocity value step and said obtaining a distance error step.

10. A vehicle steering control method, comprising the steps of:

applying a steering angle, a velocity error and a distance error to fuzzy logic membership functions to produce an output that is applied to a steering rule base;

inputting a measure of operator aggressiveness to said steering rule base;

defuzzifying an output from said steering rule base to produce a steering signal;

receiving said steering signal by a vehicle control unit; and

steering a vehicle by said vehicle control unit using said steering signal.

11. The method of claim 10, further comprising the step of inputting an operator reaction time to said vehicle control unit.

12. The method of claim 10, further comprising the step inputting a maximum turn rate of the vehicle to said vehicle control unit.

13. The method of claim 12, further comprising the step of using operator experience/perception information by said fuzzy logic membership functions.

14. The method of claim 10, further comprising the step of establishing a required path which serves as an input to obtain said distance error.

15. The method of claim 14, wherein said establishing a required path step also serves as an input to obtain said velocity error.

16. The method of claim 14, further comprising the step of using feedback information to establish a current position of the vehicle to obtain said distance error.

17. The method of claim 16, wherein said feedback information also serves as an input to obtain said velocity error.

18. The method of claim 17, further comprising the step of obtaining at least one of an orientation, a location and a velocity in said using feedback information step.