Vehicle Roll Control Method Using Controllable Friction Force of MR Dampers

• US 20080281488A1
• Filed: 08/22/2007
• Published: 11/13/2008
• Est. Priority Date: 05/08/2007
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations Incorporated (Motors Liquidation Co. GUC Trust)
• Inventors: Ryu, Jihan, Namuduri, Chandra S.
• Granted Patent: US 8,855,856 B2
• Time in Patent Office: Days
• US Class Current: 701/38
• CPC Class Codes: B60G 17/016 characterised by their responsiveness, when the vehicle is travelling, to specific motion, a specific condition, or driver input B60G17/017 takes precedence
• CPC Class Codes: B60G 17/0162 mainly during a motion involving steering operation, e.g. cornering, overtaking B60G17/0164 takes precedence
• CPC Class Codes: B60G 17/0182 involving parameter estimation, e.g. observer, Kalman filter
• CPC Class Codes: B60G 2202/23 Friction Damper
• CPC Class Codes: B60G 2400/104 lateral or transversal with regard to vehicle
• CPC Class Codes: B60G 2400/204 Vehicle speed
• CPC Class Codes: B60G 2400/41 Steering angle
• CPC Class Codes: B60G 2500/102 stepwise
• CPC Class Codes: B60G 2600/02 Retarders, delaying means, dead zones, threshold values, cut-off frequency, timer interruption
• CPC Class Codes: B60G 2600/17 Proportional control, i.e. gain control
• CPC Class Codes: B60G 2600/18 Automatic control means
• CPC Class Codes: B60G 2800/012 Rolling condition
• CPC Class Codes: B60G 2800/9122 ARS - Anti-Roll System Control

Abstract

A system for providing vehicle roll control that controls the friction-force of dampers provided at the wheels of the vehicle. The system includes a lateral acceleration sensor for determining the lateral acceleration of the vehicle, a steering angle sensor for determining the steering angle of the vehicle and a speed sensor for determining the speed of the vehicle. The system calculates a current control signal for one or more of the dampers based on the lateral acceleration and/or the steering angle, and uses one or both of the current control signals to control the friction-force of the inside, outside or both of the dampers.

Claims

1. A roll control system for a vehicle, said system comprising:

a lateral acceleration sensor for determining the lateral acceleration of the vehicle and providing a lateral acceleration signal;

a speed sensor for determining the speed of the vehicle and providing a vehicle speed signal;

a sensor for measuring a steering angle of the vehicle and providing a steering angle signal;

a damper with controllable friction force provided at each wheel of the vehicle; and

a controller for reducing the roll motion of the vehicle when it is turning by controlling the friction response of one or more of the wheel dampers, said controller receiving the lateral acceleration signal, the vehicle speed signal and the steering angle signal, and calculating a friction control signal.

2. The system according to claim 1 wherein the dampers with controllable friction force are magnetorheological dampers or electrorheological dampers.

3. The system according to claim 1 wherein the controller calculates a first current control signal based on the lateral acceleration signal and a second current control signal based on the steering angle signal.

4. The system according to claim 3 wherein the controller uses the maximum of the first and second current control signals to provide the control signal to the dampers.

5. The system according to claim 1 wherein the controller provides the friction control signal to a damper at a front wheel and a rear wheel on an inside of the vehicle relative to a turn or to a damper at a front wheel and a rear wheel at an outside of the vehicle relative to the turn or both.

6. The system according to claim 1 wherein the controller provides different control signals to dampers at the front and rear wheels of the vehicle depending on the weight distribution in the vehicle.

7. The system according to claim 1 wherein the controller models the roll motion of the vehicle as a one degree-of-freedom dynamic model.

8. The system according to claim 1 wherein the controller calculates the friction control signal based on the lateral acceleration signal using the equation:

I_roll,ay=K_ay·

|a_y|

Where I_roll,ay is the control signal, K_ay is a gain and a_y is the lateral acceleration signal.

9. The system according to claim 1 wherein the controller determines the friction control signal based on the steering angle signal using the equation:

I_roll,δ

=K_δ

·

|δ

|

Where I_roll,δ

is the friction control signal, K_δ

is a gain value and δ

is the steering angle signal.

10. The system according to claim 9 wherein the gain value K_δ

is determined by lateral acceleration and a one degree-of-freedom model using the equation;

11. A roll control system for a vehicle, said system comprising:

a damper with controllable friction force provided at each wheel of the vehicle, said dampers being used for vehicle ride purposes; and

a controller for selectively providing a current control signal to one or more of the dampers with controllable friction force in response to lateral acceleration of the vehicle so as to reduce the roll motion of the vehicle.

12. The system according to claim 11 wherein the dampers with controllable friction force are magnetorheological dampers or electrorheological dampers.

13. The system according to claim 11 wherein the controller uses a steering angle signal of the vehicle in combination with a one degree-of-freedom model to determine the current control signal applied to the dampers.

14. The system according to claim 11 wherein the controller uses a vehicle lateral acceleration signal for determining the current control signal for the dampers.

15. The system according to claim 11 wherein the controller provides the current control signal to a front and rear damper on an inside of the vehicle relative to a turn or to a front and rear damper on an outside of the vehicle relative to a turn.

16. The system according to claim 11 wherein the controller provides different control signals to the dampers at the front and rear wheels of the vehicle depending on the weight distribution in the vehicle.

17. A method for controlling the roll motion of a vehicle, said method comprising:

providing a damper with controllable friction force at each wheel of the vehicle for ride control purposes;

determining a lateral acceleration of the vehicle;

determining a steering angle of the vehicle; and

providing a current control signal to one or more of the dampers in response to turning of the vehicle as determined by the lateral acceleration or the steering angle so as to control the roll motion of the vehicle.

18. The method according to claim 17 wherein providing a damper includes providing a magnetorheologiocal damper or an electrorheological damper.

19. The method according to claim 17 wherein providing a current control signal includes selecting the current control signal from a first current control signal based on the lateral acceleration and a second current control signal based on the steering angle.

20. The method according to claim 19 wherein providing a current control signal includes selecting the current control signal from the larger of the first current control signal and the second current control signal.