Tactile feedback control for steer-by-wire systems

• US 6,535,806 B2
• Filed: 09/21/2001
• Issued: 03/18/2003
• Est. Priority Date: 01/30/2001
• Status: Expired due to Term

• Current Assignee: GM Global Technology Operations Incorporated (General Motors Company), Steering Solutions IP Holding Corporation (Nexteer Automotive Group Ltd.)
• Original Assignee: Delphi Technologies, Inc. (BorgWarner Incorporated)
• Inventors: Kaufmann, Timothy W., Petrowski, James M., Millsap, Scott A.
• Primary Examiner(s): ARTHUR JEANGLAUDE, GERTRUDE
• Application Number:
  US09/960,552
• Publication Number:
  US 20020103589A1
• Time in Patent Office: 543 Days
• Field of Search: 701/41, 701/42, 701/43, 180/422, 180/443, 180/446, 180/445, 340/465
• US Class Current: 701/42
• CPC Class Codes: B62D 5/006 power actuated
• CPC Class Codes: B62D 6/008 Control of feed-back to the steering input member, e.g. simulating road feel in steer-by-wire applications

Abstract

A steer-by-wire system includes a steering wheel; a steering wheel sensor coupled to the steering wheel for sensing the position of the steering wheel and producing a signal indicative of the position of the steering wheel; a controller in signal communication with the steering wheel sensor for receiving the signal indicative of the position of the steering wheel from the steering wheel sensor and producing a signal indicative of a desired steering wheel feedback torque; and a tactile feedback device in signal communication with the controller for receiving the signal indicative of the desired steering wheel feedback torque and providing a corresponding torque to the steering wheel.

Claims

1. A steer-by-wire system comprising:

a steering wheel;

a steering wheel sensor disposed relative to said steering wheel for sensing a position thereof and producing a signal indicative of the position of said steering wheel;

a directional control unit for providing a signal indicative of an actual vehicular direction;

a controller in signal communication with said steering wheel sensor and said directional control unit, for receiving the signal indicative of the position of said steering wheel from said steering wheel sensor and the signal indicative of the actual vehicular direction from said directional control unit, and producing a signal indicative of a desired steering wheel feedback torque; and

a tactile feedback device in signal communication with said controller for receiving the signal indicative of the desired steering wheel feedback torque and providing a corresponding torque to said steering wheel.

2. A steer-by-wire system as defined in claim 1, wherein said directional control unit in signal communication with said controller receives a signal indicative of a desired vehicular direction.

3. A steer-by-wire system as defined in claim 2 wherein said controller receives a signal indicative of a vehicular speed.

4. A steer-by-wire system as defined in claim 3 wherein said controller receives a signal indicative of a selected operating mode.

5. A steer-by-wire system as defined in claim 2 wherein said controller receives a signal indicative of a selected operating mode.

6. A steer-by-wire system as defined in claim 5 wherein said controller receives a signal indicative of a vehicular speed.

7. A steer-by-wire system as defined in claim 1 wherein said controller receives a signal indicative of a vehicular speed.

8. A steer-by-wire system as defined in claim 7 wherein said controller receives a signal indicative of a selected operating mode.

9. A steer-by-wire system as defined in claim 1 wherein said controller receives a signal indicative of a selected operating mode.

10. A steer-by-wire system as defined in claim 9 wherein said controller receives a signal indicative of a vehicular speed.

11. A tactile feedback controller for a steer-by-wire system, the feedback controller comprising:

a tactile gain function;

an error gain function;

a first summing function for receiving a tactile gain from said tactile gain function and an error signal from said error gain function, and providing a net resistance command; and

a dynamic compensation function for receiving said net resistance command from said first summing function, and providing a compensated resistance command to a tactile resistance device.

12. A tactile feedback controller as defined in claim 11, further comprising:

a converter function; and

a second summing function in signal communication with said converter function, wherein said error gain function is in signal communication with said second summing function.

13. A tactile feedback controller as defined in claim 11, further comprising:

a command gain function for receiving signals indicative of steering wheel position, vehicle speed, and selected operating mode, and providing a signal indicative of a desired vehicular direction.

14. A tactile feedback controller as defined in claim 11, further comprising a second summing function in signal communication with said first summing function for receiving a signal indicative of a measured tactile feedback motor current corresponding to a steering wheel torque.

15. A tactile feedback controller as defined in claim 11, wherein said tactile gain function provides said tactile gain in association with a directional signal detected from a directional actuator.

16. A tactile feedback controller as defined in claim 15, wherein said error gain function provides said error signal obtained by comparing said directional signal from said directional actuator with a position signal from a steering device.

17. A method for providing tactile feedback in a steer-by-wire system, the method comprising:

receiving a signal indicative of vehicular direction;

providing a tactile gain in correspondence with the signal indicative of vehicular direction;

receiving a signal indicative of steering wheel position;

converting the signal indicative of vehicular direction into the coordinates of the signal indicative of steering wheel position;

determining the difference between the converted signal and the signal indicative of steering wheel position;

receiving a signal indicative of an operating mode;

providing an error gain in correspondence with the determined difference and the signal indicative of operating mode;

receiving a signal indicative of steering wheel velocity;

summing the tactile gain and the error gain with the signal indicative of steering wheel velocity; and

dynamically compensating the summed signal to provide a signal indicative of the desired tactile feedback torque.

18. A method as defined in claim 17 wherein the signal indicative of steering wheel velocity is received by sampling the time rate of change of the signal indicative of steering wheel position.

19. A method as defined in claim 17, further comprising:

subtracting from the summed signal a signal indicative of measured tactile feedback motor current.

20. A method as defined in claim 17, further comprising:

receiving a signal indicative of vehicular speed; and

providing a command gain in correspondence with at least one of the signals indicative of steering wheel position, vehicular speed and operating mode to produce a signal indicative of a desired vehicular direction.

21. A tactile feedback controller for a steer-by-wire system, the feedback controller comprising:

means for receiving a signal indicative of vehicular direction;

means for providing a tactile gain in correspondence with the signal indicative of vehicular direction;

means for receiving a signal indicative of steering wheel position;

means for converting the signal indicative of vehicular direction into the coordinates of the signal indicative of steering wheel position;

means for determining the difference between the converted signal and the signal indicative of steering wheel position;

means for receiving a signal indicative of an operating mode;

means for providing an error gain in correspondence with the determined difference and the signal indicative of operating mode;

means for receiving a signal indicative of steering wheel velocity;

means for summing the tactile gain and the error gain with the signal indicative of steering wheel velocity; and

means for dynamically compensating the summed signal to provide a signal indicative of the desired tactile feedback torque.

22. A tactile feedback controller as defined in claim 21, further comprising:

means for subtracting from the summed signal a signal indicative of measured tactile feedback motor current to compensate for steering wheel torque.