Patent ID: 8172341

Claim:
A vehicular brake anti-lock control system comprising: a wheel speed sensor which detects a wheel speed of a wheel; and an anti-lock control device which is operable to suppress locking of the wheel by controlling a target brake fluid pressure supplied to a wheel brake based on a reference fluid pressure data pair of upper and lower values of reference fluid pressures, when it is determined based on the wheel speed detected by the wheel speed sensor that the wheel has a tendency to lock, the reference fluid pressure data pair is selected from a first stored map; wherein the antilock control device includes a target fluid pressure calculation section that calculates a target fluid pressure based on the detected wheel speed; wherein the target brake fluid pressure is controlled to periodically increase and decrease based on detected wheel speed, wherein when the target brake fluid pressure becomes less than the lower value of the reference fluid pressure data pair the target brake fluid pressure is adjusted to coincide with the lower value of the reference fluid pressure data pair, and wherein when the target brake fluid pressure becomes greater than the upper value of the reference fluid pressure data pair, the target brake fluid pressure is adjusted to a value which lies between a pressure corresponding to an uncorrected target brake fluid pressure and a pressure corresponding to the upper value of the reference fluid pressure data pair and a rate of increase of the target brake fluid pressure is corrected so as to be smaller than in a case where the target brake fluid pressure is equal to or less than the upper value; and wherein the anti-lock control device comprises: a ground load calculation section which provides at least one of detection and estimation of a ground load of the wheel; a road surface friction coefficient calculation section which provides at least one of detection and estimation of a road surface friction coefficient; and a reference fluid pressure calculation section which calculates the reference fluid pressure data pair based on the ground load and the friction coefficient by using a predetermined map.