US 6,195,606 B1Granted

Vehicle active brake control with bank angle compensation

AssigneeGeneral Motors Corporation

InventorsDavid John Barta, Aleksander Boguslaw Hac

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Abstract

An improved active brake control method which compensates for the effects of a banked road surface under both steady state and transient operating conditions of the vehicle. The control includes an observer for estimating the lateral velocity of the vehicle as a means of determining vehicle slip angle, and a time derivative of the estimated lateral velocity is used along with measured values of lateral acceleration, vehicle speed and yaw rate to compute the lateral acceleration component due to the banked road surface, referred to as the bank acceleration. The bank acceleration, in turn, is then used to correct the values of measured steering angle and the measured lateral acceleration used (1) to develop the desired yaw rate, slip angle and lateral acceleration, and (2) to estimate the surface coefficient of adhesion and slip angle. Partial compensation can be achieved by applying suitable gain factors to the computed bank acceleration, if desired.

Claims10

Dependent claims

An active brake control method utilizing differential braking of vehicle wheels to impart a desired yaw moment on the vehicle, the method comprising the steps of:

measuring longitudinal speed, yaw rate, lateral acceleration and steering angle of the vehicle;
estimating a time rate of change of lateral velocity of the vehicle based on the measured yaw rate, lateral acceleration and steering angle, and an initial estimation of lateral bank acceleration due to banking of a road surface;
updating the estimated bank acceleration based on the time rate of change of lateral velocity and the measured longitudinal speed, yaw rate and lateral acceleration;
compensating the measured lateral acceleration and steering angle based on the updated estimated lateral bank acceleration to form lateral acceleration and steering angle values that are compensated for the effects of the banking of the road surface;
determining a desired yaw rate for the vehicle based on the compensated lateral acceleration and steering angle values and the measured longitudinal speed using a reference model of the vehicle;
and
computing the desired yaw moment based on a deviation of said measured yaw rate from said desired yaw rate.

4 more elements

Dependencies are inferred from the claim text.