Control Cycle (One Wheel)

Wheel speed measured by speed sensor provides wheel deceleration and acceleration for electronic control unit. Linking individual wheel speed provides approximate vehicle reference speed.

Comparison of wheel speed with reference speed supplies slip signals. If wheel locks from too much pressure in caliper, a condition recognized by wheel speed sequence (wheel slip), pressure is held constant with no additional increase possible.

If there is a tendency toward locking because constant pressure is still too high, output solenoid valve will open to lower pressure. If pressure is low enough for wheel acceleration, pressure is not lowered but instead held constant.

When re-acceleration of wheel passes a given value, pressure is increased in between by opening input valve in solenoid valve. Signals from control unit allow hydraulic unit to actuate pressure maintenance, reduction and build-up.

Control sequence is repeated during controlled braking until brake pedal is released or until just before vehicle stops.