ADAPTIVE SUSPENSION CONTROL FOR A MOTOR VEHICLE

• US 20090254249A1
• Filed: 03/31/2009
• Published: 10/08/2009
• Est. Priority Date: 04/02/2008
• 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: GHONEIM, Youssef, HELD, Veit
• Granted Patent: US 8,214,106 B2
• Time in Patent Office: Days
• US Class Current: 701/38
• CPC Class Codes: B60G 17/0152 characterised by the action on a particular type of suspension unit B60G17/01941 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 17/0164 mainly during accelerating or braking
• CPC Class Codes: B60G 17/018 characterised by the use of a specific signal treatment or control method
• CPC Class Codes: B60G 17/019 characterised by the type of sensor or the arrangement thereof B60G17/01941 takes precedence
• CPC Class Codes: B60G 2400/0523 Yaw rate
• CPC Class Codes: B60G 2400/0533 Yaw acceleration
• CPC Class Codes: B60G 2400/104 lateral or transversal with regard to vehicle
• CPC Class Codes: B60G 2400/106 longitudinal with regard to vehicle, e.g. braking
• 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 2500/20 Spring action or springs
• CPC Class Codes: B60G 2600/20 Manual control or setting means
• CPC Class Codes: B60G 2800/016 Yawing condition

Abstract

A suspension control system for a motor vehicle having a chassis and wheels connected to the chassis by a suspension system the stiffness of which is variable under the control of the suspension control system comprises a controller adapted to modify autonomously the stiffness of the suspension system depending on a current state of motion of the vehicle.

Claims

1. A system for controlling a suspension of a motor vehicle, comprising:

a chassis;

a wheel;

a suspension system coupling the wheel and the chassis; and

a suspension control system adapted to control a variable stiffness of the suspension system, the suspension control system comprising a controller adapted to autonomously modify the variable stiffness of the suspension system depending on a current state of motion of the motor vehicle.

2. The system of claim 1, wherein the controller is connected to a lateral acceleration sensor, adapted to distinguish between a high lateral acceleration state of motion and a low lateral acceleration state of motion, and adapted to set a higher stiffness of the suspension system in the high lateral acceleration state of motion as compared to the low lateral acceleration state of motion.

3. The system of claim 1, wherein the controller is coupled to a yaw rate sensor, adapted to distinguish between a high yaw rate state of motion and a low yaw rate state of motion, and adapted to set a higher stiffness of the suspension system in the high yaw rate state as compared to the low yaw rate state.

4. The system of claim 1, wherein the controller is adapted to estimate a side-slip rate of the motor vehicle to distinguish between a high side-slip rate state of motion and a low side-slip rate state of motion and further adapted to set a higher stiffness of the suspension system in the high side-slip rate state as compared to the low side-slip rate state.

5. The system of claim 4, wherein the controller is adapted to estimate the side-slip rate from a yaw rate measured by a yaw rate sensor and a lateral acceleration measured by a lateral acceleration sensor.

6. The system of claim 1, wherein the controller is coupled to a longitudinal acceleration sensor and adapted to distinguish between a high longitudinal acceleration state of motion and a low longitudinal acceleration state of motion and further adapted to set a higher stiffness of the suspension system in the high longitudinal acceleration state as compared to the low longitudinal acceleration state.

7. The system of claim 1, wherein the controller is coupled to a longitudinal acceleration sensor and adapted to distinguish between a positive longitudinal acceleration state of motion and a negative longitudinal acceleration state of motion and further adapted to set a higher stiffness of the suspension system in the negative longitudinal acceleration state as compared to the positive longitudinal acceleration state.

8. The system of claim 1, wherein the controller is adapted to distinguish between a high forward speed state of motion and a low forward speed state of motion and further adapted to set a higher stiffness of the suspension system in the low forward speed state as compared to the high forward speed state.

9. The system of claim 1, wherein the controller is connected to a steering wheel angle sensor and adapted to distinguish between a high steering wheel angular velocity state of motion and a low steering wheel angular velocity state of motion and further adapted to set a higher stiffness of the suspension system in the high steering wheel angular velocity state as compared to the low steering wheel angular velocity state.

10. The system of claim 1, wherein the controller is adapted to determine a time derivative of a yaw rate to distinguish between a high yaw rate derivative state and a low yaw rate derivative state and further adapted to set a higher stiffness of the suspension system in the high yaw rate derivative state as compared to the low yaw rate derivative state.

11. The system claim 1, wherein a state is assigned to one of a plurality of discrete stiffness values of the suspension system.

12. The system of claim 11, wherein the controller is adapted to store at least two maps for assigning a stiffness value to the state assigned to one of the plurality of discrete stiffness values of the suspension system and further adapted to receive a user input for allowing the user to select between the at least two maps.

13. A method for controlling a stiffness of a suspension system in a motor vehicle, comprising the steps of

determining a current state of motion of the motor vehicle;

and

setting the stiffness of the suspension system to a value associated to the current state of motion when a change of the current state of motion is observed.

14. A computer readable medium embodying a program product, said program product comprising:

a stiffness control program for controlling a stiffness of a suspension in a motor vehicle, the stiffness control program configured to;

determine a current state of motion of the motor vehicle; and

set the stiffness of a suspension system to a value associated to the current state of motion when a change of the current state of motion is observed.