Methods and systems for aligning a steering system of a vehicle

Patent metadata

Field	Value
Publication number	US-9663142-B2
Application number	US-201514845779-A
Country	US
Kind code	B2
Filing date	Sep 4, 2015
Priority date	Dec 11, 2013
Publication date	May 30, 2017
Grant date	May 30, 2017

Abstract

Methods and systems are provided for aligning a steering system of a vehicle. In one embodiment, a method includes: determining when the vehicle is driving a straight-line path; determining a steering wheel position error when the vehicle is driving the straight-line path; computing a rear wheel steering offset based on the steering wheel position error and a closed loop control method; and generating a control signal to a rear wheel steering system based on the rear wheel steering offset.

First claim

What is claimed is:

1. A method of aligning a steering system of a vehicle, the method comprising:
determining when the vehicle is driving a straight-line path; and
determining a steering wheel position error when the vehicle is driving the straight-line path;
computing a rear wheel steering offset based on the steering wheel position error and a closed loop control method; and
generating a control signal to a rear wheel steering system based on the rear wheel steering offset.

2. The method of claim 1 , wherein the computing the rear wheel steering offset is based on proportional control.

3. The method of claim 1 , wherein the computing the rear wheel steering offset is based on integral control.

4. The method of claim 1 , wherein the computing the rear wheel steering offset is based on derivative control.

5. The method of claim 1 , further comprising applying a low pass filter to the steering wheel position error and wherein the computing the rear wheel steering offset is based on the filtered steering wheel position error.

6. The method of claim 5 , wherein the computing the rear wheel steering offset comprises applying at least one of a proportional coefficient, and integral coefficient, and a derivative coefficient to the filtered steering wheel position error.

7. The method of claim 1 , wherein the determining the steering wheel position error is based on a steering wheel position when the vehicle is driving the straight-line path and a predefined steering wheel position.

8. The method of claim 1 , wherein the determining when the vehicle is driving a straight-line path is based on at least one of compass data, global position system data, yaw velocity data, tire rotational speed data.

9. A system for aligning a steering system of a vehicle, comprising:
a rear wheel steering system; and
a control module that determines a steering wheel position error when the vehicle is driving the straight-line path, that computes a rear wheel steering offset based on the steering wheel position error and a closed loop control method, and that generates a control signal to the rear wheel steering system based on the rear wheel steering offset.

10. The system of claim 9 , wherein the control module computes the rear wheel steering offset based on proportional control.

11. The system of claim 9 , control module computes the rear wheel steering offset based on integral control.

12. The system of claim 9 , wherein the control module computes the rear wheel steering offset based on derivative control.

13. The system of claim 9 , wherein the control module applies a low pass filter to the steering wheel position error and wherein control module computes the rear wheel steering offset based on the filtered steering wheel position error.

14. The system of claim 13 , wherein the control module computes the rear wheel steering offset based on at least one of proportional control, integral control, and derivative control of the filtered steering wheel position error.

15. The system of claim 9 , wherein the control module determines the steering wheel position error based on a steering wheel position when the vehicle is driving the straight-line path and a predefined desired steering wheel position.

16. The system of claim 9 , wherein the control module determines when the vehicle is driving a straight-line path based on data from at least one of a compass, a global position system, a yaw velocity sensor, and a tire speed sensor.

17. The system of claim 9 , wherein the rear wheel steering system adjusts an angle of rear wheels of the vehicle based on the rear wheel steering offset.

18. The system of claim 17 , further comprising a front wheel steering system that controls an angle of front wheels of the vehicle to a substantially similar angle offset when the angle of the rear wheels is adjusted to the rear wheel angle offset.

19. A vehicle, comprising:
a rear wheel steering system;
a front wheel steering system; and
a control module that determines a misalignment associated with the front wheel steering system, and that generates a control signal to the rear wheel steering system based on the misalignment and a closed loop control method.

20. The vehicle of claim 19 , wherein the control module computes a rear wheel steering offset based on at least one of proportional control, integral control, and derivative control.

Assignees

• Gm Global Tech Operations Llc

Inventors

• Pastor Stephen R
• Amatyakul Phanu
• Kim Keun Jae

Classifications

• B62D7/159

  characterised by computing methods or stabilisation processes or systems, e.g. responding to yaw rate, lateral wind, load, road condition · CPC title

• B62D9/00

  Steering deflectable wheels not otherwise provided for (steering positon indicators B62D15/02) · CPC title

• B62D6/002 Primary

  computing target steering angles for front or rear wheels (B62D7/159 takes precedence) · CPC title