Anti-lock brake control circuit

摘要

An anti-lock brake control circuit compares the deceleration of a braked wheel with a deceleration reference and integrates the difference when wheel deceleration exceeds the reference deceleration. A resulting velocity error signal is compared with a velocity error reference and a release signal is generated while the velocity error signal exceeds the velocity error reference. Adaptive control is provided by a first order lag circuit having wheel velocity as its input and which supplies a variable portion of the deceleration reference having a slope approximately equal to the slope of the vehicle velocity profile during braking on low coefficient surfaces and having a slope less than the slope of the vehicle velocity profile during braking on high coefficient surfaces. An initial cycle and pulse circuit sets the velocity error reference to a high level for both the first cycle of anti-lock brake operation and for a time period after each brake application during anti-lock brake operation.