Antilock control device

摘要

An antilock control device has a calculating unit for calculating the vehicle speed from the wheel speed signals from wheel speed sensors, a processing/lock state detecting unit adapted to judge whether the wheels are showing a locking tendency or recovering from locked state on the basis of the signals from the wheel speed sensors and the calculating unit and produce a command to reduce or increase the braking pressure on the basis of the result of judgement, and a brake fluid pressure circuit operable in response to the pressure control command from the lock state detecting unit. The calculating unit is adapted to select the highest wheel speed and the lowest wheel speed from among the wheel speeds of all the wheels, judge whether or not the difference therebetween is smaller than a predetermined value, select the highest wheel speed as a reference wheel speed if the difference is smaller than the predetermined value and select the lowest wheel speed as the reference wheel speed if the difference is larger than the predetermined value, and calculate the vehicle speed from the reference wheel speed.