METHODS AND SYSTEMS INVOLVING RETURN TORQUE

• US 20100286869A1
• Filed: 01/23/2009
• Published: 11/11/2010
• Est. Priority Date: 01/25/2008
• Status: Active Grant

• Current Assignee: GM Global Technology Operations Incorporated (Motors Liquidation Co. GUC Trust), Steering Solutions IP Holding Corporation (Nexteer Automotive Group Ltd.)
• Original Assignee: GM Global Technology Operations Incorporated (Motors Liquidation Co. GUC Trust)
• Inventors: Boudia, Abdellatif, Katch, Gregory J., Novo, Eduardo Audino
• Granted Patent: US 8,452,493 B2
• Time in Patent Office: Days
• US Class Current: 701/41
• CPC Class Codes: B62D 5/0466 for returning the steering wheel to neutral position

Abstract

A method of controlling a motor of a power steering system is provided. The method includes: estimating a scale factor based on a vehicle speed and a hand wheel torque; applying the scale factor to a return command; and generating a motor command signal based on the applying the scale factor.

Claims

1. A method of controlling a motor of a power steering system comprising:

estimating a scale factor based on a vehicle speed and a hand wheel torque;

applying the scale factor to a return command; and

generating a motor command signal based on the applying the scale factor.

2. The method of claim 1, further comprising estimating the return command based on the vehicle speed and a hand wheel angle.

3. The method of claim 2, wherein the estimating the return command is based on a lookup table that is indexed by the vehicle speed and the hand wheel angle.

4. The method of claim 2, wherein the estimating the return command is based on a plurality of lookup tables that are indexed by the hand wheel angle, and wherein the plurality of lookup tables are each associated with a discrete vehicle speed.

5. The method of claim 4, wherein the estimating the return command further comprises interpolating the return command based on return commands from two or more of the plurality of lookup tables.

6. The method of claim 1, wherein the estimating the scale factor is based on a lookup table that is indexed by the vehicle speed and the hand wheel torque.

7. The method of claim 1, wherein the estimating the scale factor is based on a plurality of lookup tables that are indexed by the hand wheel torque, and wherein the plurality of lookup tables are each associated with a discrete vehicle speed.

8. The method of claim 7, wherein the estimating the scale factor further comprises interpolating the scale factor based on scale factors from two or more of the plurality of lookup tables.

9. A system for controlling a motor of a power steering system comprising:

a scaling module that estimates a scale factor based on a vehicle speed and a hand wheel torque; and

a return command module that applies the scale factor to a return command, and that generates a motor command signal based on the applying the scale factor.

10. The system of claim 9, further comprising a hand wheel return module that estimates the return command based on the vehicle speed and a hand wheel angle.

11. The system of claim 10, wherein the hand wheel return module estimates the return command based on a lookup table that is indexed by the vehicle speed and the hand wheel angle.

12. The system of claim 10, wherein the hand wheel return module estimates the return command based on a plurality of lookup tables that are indexed by the hand wheel angle, and wherein the plurality of lookup tables are each associated with a discrete vehicle speed.

13. The system of claim 12, wherein the hand wheel return module estimates the return command by interpolating the return command based on return commands from two or more of the plurality of lookup tables.

14. The system of claim 9, wherein the scaling module estimates the scale factor based on a lookup table that is indexed by the vehicle speed and the hand wheel torque.

15. The system of claim 9, wherein the scaling module estimates the scale factor based on a plurality of lookup tables that are indexed by hand wheel torque, and wherein the plurality of lookup tables are each associated with a discrete vehicle speed.

16. The system of claim 15, wherein the scaling module estimates the scale factor by interpolating the scale factor based on scale factors from two or more of the plurality of lookup tables.

17. A power steering system comprising:

a hand wheel;

a motor coupled to the hand wheel; and

a controller that determines a scale factor based on a vehicle speed and a torque of the hand wheel, and that generates a motor command signal to the motor based on the scale factor.

18. The system of claim 17, wherein the controller determines a return command based the vehicle speed and an angle of the hand wheel, and further generates the motor command based on the return command.

19. The system of claim 18, wherein the controller applies the scale factor to the return command to generate the motor command signal.

20. The system of claim 17, wherein the controller determines the scale factor based on one or more lookup tables that are indexed by at least one of the vehicle speed and the torque of the hand wheel.