Control of independent steering actuators to improve vehicle stability and stopping

• US 20010032748A1
• Filed: 02/12/2001
• Published: 10/25/2001
• Est. Priority Date: 02/11/2000
• 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. (Aptiv PLC)
• Inventors: Demerly, Jon Dee
• Granted Patent: US 6,719,087 B2
• Time in Patent Office: Days
• US Class Current: 180/402
• CPC Class Codes: B60T 2260/02 Active Steering, Steer-by-Wire
• CPC Class Codes: B60T 2270/402 Back-up
• CPC Class Codes: B60T 8/1755 Brake regulation specially adapted to control the stability of the vehicle, e.g. taking into account yaw rate or transverse acceleration in a curve road vehicle drive control systems for control of driving stability otherwise than by controlling a particular sub-unit B60W30/02
• CPC Class Codes: B60T 8/885 using electrical circuitry
• CPC Class Codes: B62D 11/08 using brakes or clutches as main steering-effecting means
• CPC Class Codes: B62D 11/183 Control systems therefor
• CPC Class Codes: B62D 17/00 Means on vehicles for adjusting camber, castor, or toe-in
• CPC Class Codes: B62D 5/003 Backup systems, e.g. for manual steering B62D5/30 takes precedence
• CPC Class Codes: B62D 6/002 computing target steering angles for front or rear wheels B62D7/159 takes precedence
• CPC Class Codes: B62D 9/007 Emergency systems using the steering system for braking

Abstract

An independent steering and/or braking control to improve motor vehicle stability and stopping utilizes a steer-by-wire system that includes a steering input system, a controller in electronic communication with the steering input system, and a plurality of roadwheel systems. Each of the roadwheel systems is in electronic communication with the controller, and each roadwheel system includes a steering actuator and a steerable wheel rotatably and operably connected to the steering actuator. The steerable wheel is configured to be angled independent of other steerable wheels and relative to a direction of travel of the motor vehicle. A method of stopping the motor vehicle as it travels includes angling a pair of the steerable wheels thereof in opposing directions. The direction of the motor vehicle can also be controlled by angling the pair of steerable wheels in opposing directions and adjusting the angle of the pair of steerable wheels If the motor vehicle is articulating a turn, its direction of travel can also be controlled by angling one of the steerable wheels and steering with the other of the steerable wheels. In addition, the angle of the steerable wheels can be adjusted to compensate for lateral disturbance without driver involvement.

Claims

1. A steer-by-wire system for a motor vehicle, comprising:

a steering input system;

a controller in electronic communication with said steering input system; and

a plurality of roadwheel systems, each being in electronic communication with said controller, and each of said roadwheel systems comprising,

a steering actuator, and

a steerable wheel rotatably and operably connected to said steering actuator, said steerable wheel being configured to be angled relative to a direction of travel of said motor vehicle.

2. The steer-by-wire system of

claim 1

wherein said steering input system comprises:

a steering column;

a steering device disposed on said steering column;

a resistance torque mechanism operably connected to said steering column; and

at least one sensor disposed on said steering column, said at least one sensor being in electronic communication with said controller.

3. The steer-by-wire system of

claim 2

wherein electronic communication is maintained between said steering actuator and said resistance torque mechanism through said controller.

4. The steer-by-wire system of

claim 1

wherein said controller comprises:

at least one input port, said at least one input port being configured to receive inputs;

a normal steering control in electronic communication with said at least one input port; and

a failed brake steering control device in electronic communication with said at least one input port.

5. The steer-by-wire system of

claim 4

wherein said failed brake steering control device comprises:

a first failed brake steering controller in electronic communication with said steering actuator; and

a second failed brake steering controller in electronic communication with said steering actuator.

6. The steer-by-wire system of

claim 5

wherein said first failed brake steering controller is configured to allow for the braking of said motor vehicle followed by the steering of said motor vehicle.

7. The steer-by-wire system of

claim 5

wherein said second failed brake steering controller is configured to allow for the steering of said motor vehicle followed by the braking of said motor vehicle.

8. The steer-by-wire system of

claim 4

wherein said steering actuator is in electrical communication with said normal steering control and said failed brake steering control.

9. The steer-by-wire system of

claim 1

wherein said steerable wheel is configured to turn up to about 40 degrees out of a straight line direction of travel of said motor vehicle.

10. The steer-by-wire system of

claim 1

wherein a number of independent inputs may be made into a corresponding number of steering actuators to effectuate compensation for lateral disturbances experienced by said motor vehicle.

11. A method of decelerating a moving motor vehicle, comprising:

angling a pair of steerable wheels in opposing directions.

12. The method of stopping a moving motor vehicle of

claim 11

wherein said angling of said pair of steerable wheels is toward each other.

13. A method of directional control of a moving motor vehicle, comprising:

angling a pair of steerable wheels in opposing directions to brake said motor vehicle; and

adjusting an angle of said pair of said steerable wheels to control a direction of said motor vehicle.

14. A method of directional control of a motor vehicle moving through a turn, comprising:

angling a first steerable wheel; and

steering said motor vehicle with a second steerable wheel.

15. The method of directional control of

claim 14

wherein said first steerable wheel is positioned proximate an outside of said turn and wherein said second steerable wheel is positioned proximate an inside of said turn.

16. The method of directional control of

claim 14

further comprising:

adjusting said first steerable wheel and said second steerable wheel based on lateral response experienced by said motor vehicle.