Patent ID: 7938494

Claim:
An antilock braking system (ABS) optimizing wheel slip of a land or aircraft vehicle with respect to a ground surface to maximize braking performance of a wheel against a ground surface during ABS braking by an operator of the vehicle comprising: brake means responsive to operator braking for generating an applied brake torque that is applied to a wheel brake to initiate braking at the contact point of the wheel and the ground surface; a wheel speed sensor that periodically measures wheel speed; a sliding mode observer that estimates an estimated differential wheel torque from each wheel speed measurement that represents the difference between wheel braking torque, generated at the contact point of the wheel and the ground surface, and the applied brake torque; an extrema detector that compares each value of estimated differential wheel torque to a preceding value of estimated differential wheel torque to detect an extremum of estimated differential wheel torque; and a controller that interrupts braking by the brake means upon detection of an extremum during ABS braking, thereby causing applied brake torque to decrease.