Abstract: A controller includes an initial current value calculation unit calculating an initial current value to open a normally open linear solenoid valve when a hydraulic pressure is shifted from a pressure reducing state or a pressure holding state to a pressure increasing state, a valve opening amount increasing unit reducing the energization amount from the initial current value so that a valve opening amount of the normally open linear solenoid valve increases, an offsetting necessity determination unit determining based on a predetermined condition whether or not the energization amount needs to be offset to an increase side when the valve opening amount increasing unit reduces the energization amount, and an energization amount offsetting unit offsetting at least once the energization amount to an increase side only for a predetermined time period when it is determined that such offsetting is necessary.

Abstract: A controller 20 includes an initial current value calculation unit 22 calculating an initial current value to open a normally open linear solenoid valve when a hydraulic pressure is shifted from a pressure reducing state or a pressure holding state to a pressure increasing state, a valve opening amount increasing unit 23 reducing the energization amount from the initial current value so that a valve opening amount of the normally open linear solenoid valve increases, an offsetting necessity determination unit 24 determining based on a predetermined condition whether or not the energization amount needs to be offset to an increase side when the valve opening amount increasing unit 23 reduces the energization amount, and an energization amount offsetting unit 25 offsetting at least once the energization amount to an increase side only for a predetermined time period when it is determined that such offsetting is necessary.