Abstract: A vehicle antilock brake system provides an adaptive apply bump period at the beginning of the apply phase of a antilock brake pressure cycle that provides rapid recovery of the correct amount of pressure for all braking conditions. The apply bump period is established based upon the wheel acceleration and the peak acceleration attained by the wheel during recovery from an incipient wheel lock condition. In particular, the apply bump is initiated when recovery from an incipient wheel lock condition is first sensed and thereafter terminated when the wheel acceleration decreases to below a threshold value that is a predetermined function of the peak acceleration of the wheel during recovery from an incipient wheel lock condition in the ABS pressure cycle.

Abstract: An antilock brake controller provides an adaptive pressure hold period that interrupts the release of brake pressure during the pressure release phase of an antilock braking pressure control cycle of a vehicle wheel by holding the brake pressure constant while the wheel slip rate is below a threshold that is adjusted as a predetermined function of wheel slip for the front wheels and as a predetermined function of wheel acceleration for the rear wheels.

Abstract: During the apply phase of an ABS pressure cycle in a system having a motor driven pressure modulator, the motor current is controlled to an apply bump motor current value during the initial period of the apply phase for a wheel parameter dependent duration to quickly recover brake pressure after which an initial apply current is established in the motor from which value the current is ramped to ramp brake pressure. The duration of the apply bump current is monitored and when the duration exceeds a minimum value, representing the time required for the apply bump current to reverse the motor direction from pressure release to pressure apply and to establish the motor speed at a steady state condition whereat the motor current is a reliable measurement of the applied brake pressure, the actual motor current at the end of the apply bump is used as the initial apply current.