US 2006/0136112 A1Published application

Active front steer control for vehicle stability enhancement

AssigneeGeneral Motors Corporation

InventorsWilliam Lin, Youssef Ghoneim

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Abstract

An AFS control system that combines and weights yaw rate feedback and side-slip rate feedback to provide increased vehicle stability enhancement control. The AFS system includes a yaw rate sub-system that generates a desired yaw rate signal. The AFS system also includes a side-slip rate sub-system that generates a desired side-slip rate feedback signal. The AFS system further includes a side-slip rate feedback sub-system that generates a side-slip rate feedback signal. The AFS system also includes a yaw rate feedback sub-system that generates a yaw rate feedback signal. The yaw rate feedback signal and the side-slip rate feedback signal are integrated in a control integration sub-system that generates a stability enhancement control signal. The control integration sub-system determines whether the vehicle is in an oversteer or understeer condition, and weights the desired yaw rate feedback signal accordingly based on the vehicle condition.

Claims20

Dependent claims

A method for providing active front steering for a vehicle, said method comprising:

providing a vehicle speed signal of the vehicle;
providing a lateral acceleration signal of the lateral acceleration of the vehicle;
providing an actual yaw rate signal of the actual yaw rate of the vehicle;
providing a steering angle signal indicative of the vehicle operator's desired steering direction;
determining a desired yaw rate of the vehicle based on the steering angle signal and the vehicle speed signal;
determining a desired side-slip rate of the vehicle based on the steering angle signal and the vehicle speed signal;
determining a yaw rate feedback signal based on the desired yaw rate signal and the actual yaw rate signal;
determining a side-slip rate feedback signal based on the desired side-slip rate signal, the vehicle speed signal, the vehicle yaw rate signal and the vehicle lateral acceleration signal;
and
integrating the yaw rate feedback signal and the side-slip rate feedback signal to generate a stability enhancement control signal used for providing the active front steering of the vehicle, wherein integrating the yaw rate feedback signal and the side-slip rate feedback signal includes weighting one or both of the yaw rate feedback signal and the side-slip rate feedback signal.

7 more elements

An active front steering system for a vehicle, said system comprising:

a hand-wheel sensor for generating a steering angle signal indicative of a vehicle operator's intended steering direction;
a vehicle speed sensor for providing a vehicle speed signal of the speed of the vehicle;
a yaw rate sensor for providing an actual yaw rate signal of the yaw rate of the vehicle;
a lateral acceleration sub-system for providing a lateral acceleration signal of the lateral acceleration of the vehicle;
a yaw rate command sub-system responsive to the steering angle signal and the vehicle speed signal, said yaw rate command sub-system generating a desired yaw rate signal;
a side-slip rate sub-system responsive to the steering angle signal and the vehicle speed signal, said side-slip rate sub-system generating a desired side-slip rate signal;
a yaw rate feedback sub-system responsive to the desired yaw rate signal and the actual yaw rate signal, said yaw rate feedback sub-system generating a yaw rate feedback signal;
a side-slip rate feedback sub-system responsive to the lateral acceleration signal, the actual yaw rate signal, the vehicle speed signal and the desired side-slip rate signal, said side-slip rate feedback sub-system providing a side-slip rate feedback signal;
and
a control integration sub-system responsive to the yaw rate feedback signal and the side-slip rate feedback signal, said control integration sub-system weighting the yaw rate feedback signal and/or the side-slip rate feedback signal to provide a stability enhancement control signal for controlling the front steering of the vehicle.

7 more elements

Dependencies are inferred from the claim text.

Facts

Application: 11/017,412Filed 20 Dec 2004
Published: 22 Jun 2006
Term ends: Not estimatedThe source records don’t support an estimate.

Classification6 codes

B62D 6/003
Computing target steering angles for front or rear wheels: in order to control vehicle yaw movement, i.e. around a vertical axis
B62D 5/008
Power-assisted or power-driven steering: changing the transfer ratio between the steering wheel and the steering gear by variable supply of…
B60T 2230/02
Monitoring, detecting special vehicle behaviour; Counteracting thereof: side slip angle, attitude angle, floating angle, drift angle
B60T 2260/02
Interaction of vehicle brake system with other systems: active Steering, Steer-by-Wire