Patent ID: 7654935

Claim:
A shift control system for a continuously variable transmission of a vehicle having a hydraulic actuator that is driven with a hydraulic fluid supplied thereto or discharged therefrom so as to continuously change a speed ratio of the transmission, wherein a drive command value for use in drive control of a shift control valve that adjusts an amount of the hydraulic fluid flowing into or out of the hydraulic actuator is obtained based on a feedforward controlled variable that is determined based on an amount of change of a target value for use in shift control of the continuously variable transmission, comprising: an estimated pressure difference calculating unit that calculates an estimated value of a pressure difference between an upstream hydraulic pressure and a downstream hydraulic pressure of the shift control valve; a maximum flow calculating unit that calculates a maximum flow amount as the maximum amount of the hydraulic fluid that can flow into or out of the hydraulic actuator when the drive command value is set to a predetermined value, based on the estimated value of the pressure difference; a guard value calculating unit that calculates a guard value of the amount of change of the target value, based on the maximum flow amount; and a target value setting unit that performs a guard process for restricting the amount of change of the target value, using the guard value, so as to set the target value.