Robust steering-pull torque compensation

• US 6,965,820 B2
• Filed: 09/18/2001
• Issued: 11/15/2005
• Est. Priority Date: 09/18/2001
• 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: Deng, Weiwen, Pattok, Kathryn L., Lin, William Chin-Woei, Colosky, Mark P., Chin, Yuen-Kwok, Chandy, Ashok, Amberkar, Sanket S.
• Primary Examiner(s): Black, Thomas G.
• Assistant Examiner(s): Broadhead, Brian J.
• Application Number:
  US09/954,886
• Publication Number:
  US 20030055543A1
• Time in Patent Office: 1,519 Days
• Field of Search: 701/41, 701/42, 701/43, 180/410, 180/420, 180/421, 180/443, 180/446, 280/89.11, 280/93.501
• US Class Current: 701/41
• CPC Class Codes: B62D 5/0472 for damping vibrations
• CPC Class Codes: B62D 6/04 responsive only to forces disturbing the intended course of the vehicle, e.g. forces acting transversely to the direction of vehicle travel

Abstract

A controller (32) for a vehicular system (10) that includes a hand-wheel (16) and an electric motor (34) includes a torque-assist function (56) responsive to a signal representing the torque applied to the hand-wheel (16) for providing a torque-assist command to the motor (34), and a steering-pull compensator (52) responsive to a signal representing a valid ignition cycle for modifying the torque-assist command to the motor (34) by an offset corresponding to a detected steering-pull condition; where the method of control includes receiving the signal indicative of the torque applied to the hand-wheel (16), providing a torque-assist command to the motor (34) in response to the received torque signal, detecting an enabling signal related to the signal representing a valid ignition cycle, quantifying a steering-pull condition in response to the received and detected signals, and modifying the torque-assist command to the motor (34) by an offset corresponding to the quantified steering-pull condition.

Claims

1. A controller for a vehicular system, the controller comprising:

a torque-assist function responsive to a signal indicative of an input device torque for providing a torque-assist command to an electric motor; and

a steering-pull compensator including a filter responsive to the signal indicative of input device torque, said compensator being responsive to a signal indicative of a valid detection cycle for modifying said torque-assist command to the electric motor by an offset corresponding to a detected steering-pull condition.

2. A controller as defined in claim 1, further comprising:

at least one summing function in signal communication with said torque-assist function and with said steering-pull compensator for summing the provided torque-assist command with the offset corresponding to a detected input device pull condition.

3. A controller as defined in claim 2, said steering-pull compensator comprising:

a function block for providing a signal to a non-inverting input of the summing function.

4. A controller as defined in claim 1, said steering-pull compensator comprising:

a memory switch configured such that an output signal there from is also received as an input at an input terminal.

5. A controller for a vehicular system, the controller comprising:

a torque-assist function responsive to a signal indicative of an input device torque for providing a torque-assist command to an electric motor; and

a steering-pull compensator including a condition processing block for determining if the vehicle is being driven in a substantially straight path, said compensator being responsive to a signal indicative of a valid detection cycle for modifying said torque-assist command to the electric motor by an offset corresponding to a detected steering-pull condition.

6. A controller for a vehicular system, the controller comprising:

a torque-assist function responsive to a signal indicative of an input device torque for providing a torque-assist command to an electric motor; and

a steering-pull compensator responsive to a signal indicative of a valid detection cycle for modifying said torque-assist command to the electric motor by an offset corresponding to a detected steering-pull condition, said steering-pull compensator further including an enable block for validating the detected steering-pull condition.

7. A controller as defined in claim 6, said steering-pull compensator comprising:

an enabling switch for receiving a binary control signal from said enable block.

8. A controller as defined in claim 7, said steering-pull compensator further comprising:

a delay unit for delaying the offset correction until the enabling switch transitions off-to-on.

9. A controller as defined in claim 8, said steering-pull compensator further comprising:

a summing function for adding the delayed offset correction to a previous offset value.

10. A method for controlling a vehicular system, the method comprising:

receiving a signal indicative of a torque applied to an input device;

providing a torque-assist command to a motor in response to the received torque signal;

detecting an enabling signal;

quantifying a steering-pull condition in response to the received and detected signals;

modifying the torque-assist command to the motor by an offset corresponding to the quantified steering-pull condition;

monitoring a vehicle ignition signal;

recognizing an off-to-on transition of the monitored ignition signal;

disabling the enabling signal in response to the recognized transition;

determining whetter at least one of the duration of the monitored ignition signal exceeds a threshold duration value and the distance traveled by the vehicle exceeds a threshold distance value; and

enabling the enabling signal in correspondence with said determining when the duration exceeds the threshold.

11. A method as defined in claim 10, further comprising:

recognizing a cycle as an off-to-on transition of the monitored ignition signal followed by an on-to-off transition of the monitored ignition signal; and

storing a steering-pull compensation value corresponding to the quantified condition into a memory location upon detecting of an enabled enabling signal for a recognized cycle.

12. A method as defined in claim 11, further comprising:

adding the stored steering-pull compensation value to the provided torque-assist command at the beginning of a cycle in accordance wit the steering-pull compensation value stored in a previous cycle.

13. A method as defined in claim 11, further comprising:

adding the stored steering-pull compensation value to the provided torque-assist command at the beginning of a cycle in accordance with the steering-pull compensation values stored in a plurality of previous cycles.

14. A method as defined in claim 11, further comprising:

retrieving at least one steering-pull compensation value stored in a previous cycle far analysis during vehicle service.

15. A method as defined in claim 11, further comprising:

writing a modified steering-pull compensation value corresponding to an adjusted vehicular mechanical specification into a memory location following corrective vehicle service.

16. A method as defined in claim 11, further comprising:

writing a zero steering-pull compensation value into a memory location following vehicle service.

17. A method as defined in claim 10 wherein the threshold duration value is about five minutes.

18. A method as defined in claim 10 wherein the threshold distance value is about three miles.

19. A vehicular system comprising:

an input device;

a controller in signal communication with said input device;

an electric motor in signal communication with said controller;

said controller comprising;

a torque-assist function responsive to a signal indicative of an input device torque for providing a torque-assist command to said electric motor; and

a steering-pull compensator including a filter responsive to the signal indicative of input device torque, said compensator being responsive to a signal indicative of a valid detection cycle for modifying said torque-assist command to said electric motor by an offset corresponding to a detected steering-pull condition.

20. A vehicular system as defined in claim 19, said controller further comprising:

at least one summing function in signal communication with said torque-assist function and with said steering-pull compensator for summing the provided torque-assist command with the offset corresponding to a detected input device pull condition.

21. A vehicular system as defined in claim 24, said steering-pull compensator comprising:

a function block for providing a signal to a non-inverting input of the summing function.

22. A vehicular system as defined in claim 19, said steering-pull compensator comprising:

a condition processing block for determining if the vehicle is being driven in a substantially straight path.

23. A vehicular system as defined in claim 19, said steering-pull compensator comprising:

an enable block for validating the detected steering-pull condition.

24. A vehicular system as defined in claim 23, said steering-pull compensator comprising:

an enabling switch for receiving a binary control signal from said enable block.

25. A vehicular system as defined in claim 23, said steering-pull compensator further comprising:

a delay unit for delaying the offset correction until the enabling switch transitions off-to-on.

26. A vehicular system as defined in claim 23, said steering-pull compensator further comprising:

a summing function for adding the delayed offset correction to a previous offset value.

27. A vehicular system as defined in claim 23, said steering-pull compensator comprising:

a memory switch for receiving its own output signal at its primary input terminal.