Systems and methods involving quadrant dependent active damping

• US 8,296,011 B2
• Filed: 12/12/2007
• Issued: 10/23/2012
• 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: Steering Solutions IP Holding Corporation (Nexteer Automotive Group Ltd.)
• Inventors: Hales, Michael K, Champagne, Anthony J
• Primary Examiner(s): Nguyen, John
• Assistant Examiner(s): WHALEN, MICHAEL F
• Application Number:
  US11/955,347
• Publication Number:
  US 20090157258A1
• Time in Patent Office: 1,777 Days
• Field of Search: 180/443, 180/446, 701/41, 701/42
• 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 includes a first adjustable deadband center and imparts a defined first hysteresis in the system, the first adjustable deadband center adjusts based on a value of the first signal and whether the value is increasing or decreasing;

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 includes a second adjustable deadband center and imparts a defined second hysteresis in the system, the second adjustable deadband center adjusts on a value of the second signal and whether the value is increasing or decreasing;

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 active damping signal is partially defined by the first signal and the second signal.

6. 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 includes a first adjustable deadband center and imparts a defined first hysteresis in the system, the first adjustable deadband center adjusts based on a value of the first signal and whether the value is increasing or decreasing;

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 includes a second adjustable deadband center and imparts a defined second hysteresis in the system, the second adjustable deadband center adjusts on a value of the second signal and whether the value is increasing or decreasing;

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, 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.

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 includes a first adjustable deadband center and imparts a defined first hysteresis in the system, the first adjustable deadband center adjusts based on a value of the first signal and whether the value is increasing or decreasing, 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 includes a second adjustable deadband center and imparts a defined second hysteresis in the system, multiply the first signal with the second signal resulting in a product signal, the second adjustable deadband center adjusts based on a value of the second signal and whether the value is increasing or decreasing, 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 active damping signal is partially defined by the first signal and the second signal.

12. 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 includes a first adjustable deadband center and imparts a defined first hysteresis in the system, the first adjustable deadband center adjusts based on a value of the first signal and whether the value is increasing or decreasing, 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 includes a second adjustable deadband center and imparts a defined second hysteresis in the system, multiply the first signal with the second signal resulting in a product signal, the second adjustable deadband center adjusts based on a value of the second signal and whether the value is increasing or decreasing, 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, 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.

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 includes an adjustable deadband center and imparts a defined hysteresis in the system, the adjustable deadband center adjusts based on a value of the signal and whether the value is increasing or decreasing;

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, 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.