SYSTEMS AND METHODS INVOLVING QUADRANT DEPENDENT ACTIVE DAMPING

• US 20090157258A1
• Filed: 12/12/2007
• Published: 06/18/2009
• Est. Priority Date: 12/12/2007
• 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: Delphi Technologies, Inc. (BorgWarner Incorporated)
• Inventors: Hales, Michael K, Champagne, Anthony J
• Granted Patent: US 8,296,011 B2
• Time in Patent Office: Days
• US Class Current: 701/41
• CPC Class Codes: B62D 5/0463 calculating assisting torque from the motor based on driver input
• 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 method for controlling a steering system, including, receiving a first signal representative of a torque applied to a steering wheel, receiving a second signal representative of a motor velocity of a motor operatively linked to the steering wheel, multiplying the first signal with the second signal resulting in a product signal, applying a backlash function to the product signal, wherein the backlash function imparts a defined hysteresis in the system, multiplying a defined first-third quadrant scaling factor with an active damping signal, and sending a resultant motor command signal to the motor responsive to determining that the product signal is a positive signal, and multiplying a defined second-fourth quadrant scaling factor with the active damping signal, and sending the resultant motor command signal to the motor responsive to determining that the product signal is a negative signal.

Claims

1. A method for controlling a power steering system, the method including:

receiving a first signal representative of a torque applied to a steering wheel;

applying a first backlash function to the first signal, wherein the first backlash function imparts a defined first hysteresis in the system;

receiving a second signal representative of a motor velocity of a motor operatively linked to the steering wheel;

applying a second backlash function to the second signal, wherein the second backlash function imparts a defined second hysteresis in the system;

multiplying the first signal with the second signal resulting in a product signal;

multiplying a defined first-third quadrant scaling factor with an active damping signal, and sending a resultant motor command signal to the motor responsive to determining that the product signal is a positive signal; and

multiplying a defined second-fourth quadrant scaling factor with the active damping signal, and sending the resultant motor command signal to the motor responsive to determining that the product signal is a negative signal.

2. The method of claim 1, further comprising:

filtering the first signal with a first low-pass filter responsive to receiving the first signal; and

filtering the second signal with a second low-pass filter responsive to receiving the second signal.

3. The method of claim 1, further comprising:

adding a second damping signal to the resultant motor command signal to define a scaled motor command signal; and

sending the scaled motor command signal to the motor.

4. The method of claim 1, further comprising:

adding a second torque signal to the resultant motor command signal to define a scaled motor command signal; and

sending the scaled motor command signal to the motor.

5. The method of claim 1, wherein the first backlash function is defined as a current output=y, a current input=x, a previous output=yprev, and a deadband, d:

if x<

yprev−

d/2, y=x+d/2,

else if x<

=yprev−

d/2, y=yprev

else y=x−

d/2.

6. The method of claim 1, wherein the active damping signal is partially defined by the first signal and the second signal.

7. A power steering system, comprising:

a steering wheel;

a motor operatively linked to the steering wheel;

a torque sensor operatively linked to the motor;

a processor configured to receive a first signal from the torque sensor representative of a torque applied to the steering wheel, apply a first backlash function to the first signal, wherein the first backlash function imparts a defined first hysteresis in the system, receive a second signal from the motor representative of a motor velocity of a motor operatively linked to the steering wheel, convert the second signal to represent a motor velocity of the motor, apply a second backlash function to the second signal, wherein the second backlash function imparts a defined second hysteresis in the system, multiply the first signal with the second signal resulting in a product signal, multiply a defined first-third quadrant scaling factor with an active damping signal, and send a resultant motor command signal to the motor responsive to determining that the product signal is a positive signal, and multiply a defined second-fourth quadrant scaling factor with the active damping signal, and send the resultant motor command signal to the motor responsive to determining that the product signal is a negative signal.

8. The system of claim 7, wherein the processor is further operative to:

filter the first signal with a first low-pass filter responsive to converting the first signal; and

filter the second signal with a second low-pass filter responsive to converting the second signal.

9. The system of claim 7, wherein the processor is further operative to:

add a second damping signal to the resultant motor command signal to define a scaled motor command signal; and

send the scaled motor command signal to the motor.

10. The system of claim 7, wherein the processor is further operative to:

adding a second torque signal to the resultant motor command signal to define a scaled motor command signal; and

sending the scaled motor command signal to the motor.

11. The system of claim 7, wherein the first backlash function is defined as a current output=y, a current input=x, a previous output=yprev, and a deadband, d:

if x<

yprev−

d/2, y=x+d/2,

else if x<

=yprev+d/2, y=yprev

else y=x−

d/2.

12. The system of claim 7, wherein the active damping signal is partially defined by the first signal and the second signal.

13. A method for controlling a power steering system, the method including:

receiving a first signal representative of a torque applied to a steering wheel;

receiving a second signal representative of a motor velocity of a motor operatively linked to the steering wheel;

multiplying the first signal with the second signal resulting in a product signal;

applying a backlash function to the product signal wherein the backlash function imparts a defined hysteresis in the system;

multiplying a defined first-third quadrant scaling factor with an active damping signal, and sending a resultant motor command signal to the motor responsive to determining that the product signal is a positive signal; and

multiplying a defined second-fourth quadrant scaling factor with the active damping signal, and sending the resultant motor command signal to the motor responsive to determining that the product signal is a negative signal.

14. The method of claim 15, further comprising filtering the product signal with a low-pass filter responsive to receiving the signal.

15. The method of claim 13, further comprising:

adding a second damping signal to the resultant motor command signal to define a scaled motor command signal; and

sending the scaled motor command signal to the motor.

16. The method of claim 13, further comprising:

adding a second torque signal to the resultant motor command signal to define a scaled motor command signal; and

sending the scaled motor command signal to the motor.

17. The method of claim 13, wherein the first backlash function is defined as a current output=y, a current input=x, a previous output=yprev, and a deadband, d:

if x<

yprev−

d/2, y=x+d/2,

else if x<

=yprev+d/2, y=yprev

else y=x−

d/2.