Patent ID: 6246946
Filing Date: 2001-06-12
Classification: B60T

Abstract:
An automotive brake control system, comprising:a hydraulic modulator capable of regulating wheel-brake cylinder pressures of each of road wheels of an automotive vehicle, independently of each other;wheel-speed sensors detecting wheel speeds of each of the road wheels; anda skid control unit configured to be electronically connected to said hydraulic modulator, for operating said hydraulic modulator in response to input information signals from said wheel-speed sensors to prevent a wheel lock-up condition of each of the road wheels; said skid control unit comprising:(a) a comparator determining whether the vehicle is running in a resonant speed range in which there is an increased tendency of occurrence of resonance between sprung and unsprung masses in at least one of a vehicle suspension vibrating system and a brake vibrating system, or in a non-resonant speed range except the resonant speed range,(b) a vehicle deceleration arithmetic-calculation section arithmetically calculating a vehicle deceleration .DELTA.Vi on a basis of a first speed V0 corresponding to the pseudo vehicle speed calculated at a time when the vehicle starts to decelerate and a second speed Vp corresponding to the pseudo vehicle speed calculated at a time when the pseudo vehicle speed is changed from an increasing state to a decreasing state at each cycle of skid control, from a predetermined expression .DELTA.Vi=(V0-Vp)/T, where V0 denotes the first speed, Vp denotes the second speed, and T denotes a derivative time corresponding to a period of time from the time when the vehicle starts to decelerate to the time when the pseudo vehicle speed is changed from the increasing state to the decreasing state,(c) a pseudo-vehicle-speed arithmetic-calculation section selecting a highest wheel speed of the wheel speeds as a reference value when the vehicle is running in the non-resonant speed range or during skid control, and selecting a wheel speed except the highest wheel speed from the wheel speeds as the reference value when the vehicle is running in the resonant speed range, and arithmetically calculating the pseudo vehicle speed on the basis of the reference value and the vehicle deceleration .DELTA.Vi during deceleration of the vehicle, and(d) a compensation section compensating for the pseudo vehicle speed by adding a correction value .DELTA.VHR0 to the first speed V0 when the vehicle is running in the resonant speed range.