Abstract: An anti-skid control apparatus comprises an anti-skid control means for controlling a pressure reducing valve and a pressure increasing valve, each of which operated for a target wheel when an anti-skid condition is established for the target wheel, the pressure increasing valve controlled in order to linearly change a pressure difference, an estimating means for estimating an occurrence of a factor by which the brake hydraulic pressure is fluctuated at the conduit connecting the master cylinder to the pressure increasing valve for the target wheel while the pressure increasing valve is controlled for the target wheel, and an output means for generating an output for maintaining the pressure difference during a predetermining time period in which the pressure increasing valve is controlled, when the occurrence of the factor is estimated.

Abstract: An ABS control apparatus employs a normally-open linear solenoid valve as a pressure-increasing valve, and repeatedly performs ABS control composed of pressure-reducing control and linear pressure-increasing control. This apparatus determines an initial value Pw0 of an estimated wheel cylinder pressure value Pw in consideration of brake operation time before start of ABS control Tstp and vehicle body deceleration at the start of a first-time ABS control, and then determines the estimated wheel cylinder pressure value Pw during the ABS control on the basis of the value Pw0 and the pressure-reducing characteristic of a pressure-reducing valve. This apparatus determines instruction current supplied to the pressure-increasing valve during the linear pressure-increasing control, while using an estimated differential pressure Pdiff (=(Pw0?Pw)+Pup1+Pup2), wherein Pup1 and Pup2 are set in accordance with the time Tstp and additional brake operation during the ABS control, respectively.

Abstract: An anti-skid control apparatus comprises an anti-skid control means for controlling a pressure reducing valve and a pressure increasing valve, each of which operated for a target wheel when an anti-skid condition is established for the target wheel, the pressure increasing valve controlled in order to linearly change a pressure difference, an estimating means for estimating an occurrence of a factor by which the brake hydraulic pressure is fluctuated at the conduit connecting the master cylinder to the pressure increasing valve for the target wheel while the pressure increasing valve is controlled for the target wheel, and an output means for generating an output for maintaining the pressure difference during a predetermining time period in which the pressure increasing valve is controlled, when the occurrence of the factor is estimated.

Abstract: An ABS control apparatus employs a normally-open linear solenoid valve as a pressure-increasing valve, and repeatedly performs ABS control composed of pressure-reducing control and linear pressure-increasing control. This apparatus determines an initial value Pw0 of an estimated wheel cylinder pressure value Pw in consideration of brake operation time before start of ABS control Tstp and vehicle body deceleration at the start of a first-time ABS control, and then determines the estimated wheel cylinder pressure value Pw during the ABS control on the basis of the value Pw0 and the pressure-reducing characteristic of a pressure-reducing valve. This apparatus determines instruction current supplied to the pressure-increasing valve during the linear pressure-increasing control, while using an estimated differential pressure Pdiff (=(Pw0?Pw)+Pup1+Pup2), wherein Pup1 and Pup2 are set in accordance with the time Tstp and additional brake operation during the ABS control, respectively.

Abstract: An antilock brake control system with a learning and correction function includes a slippage detector for detecting a slip value representing the slipping of a tire to a road surface. The slip value is compared with a slip threshold, and a locking symptom signal is produced when the slip value exceeds the slip threshold. A brake pressure suppression starts when the locking symptom signal is produced. A slippage learning arrangement is provided for learning, during a learning period from the start of brake pressure suppression until the tire stabilizes, whether a maximum of the slip value during the learning period is within a predetermined range, is greater than the predetermined range, or is less than the predetermined range. The slip threshold is corrected such that when the maximum slip value is greater than the predetermined range, the slip threshold is decreased, and when the maximum slip value is less than the predetermined range, the slip threshold is increased.