Jatco Corporation

Nissan Motor Company Limited

Yoshio Morita

Takashige Hinami

Takaaki Matsui

Takayuki Nagase

A hydraulic pressure control apparatus includes a solenoid valve; a hysteresis hydraulic pressure correction amount calculation section calculating a hysteresis hydraulic pressure correction amount and a command current control section controlling the command current in accordance with the hysteresis hydraulic pressure correction amount. The hysteresis hydraulic pressure correction amount calculation section has, as a reference map, a full hysteresis characteristic, and is configured to make a plurality of reduction maps obtained by reducing the reference map in accordance with a turn-round position at one of minor loops from a past to a present time when the minor loop continues, and to calculate the hysteresis hydraulic pressure correction amount by summation of hysteresis hydraulic pressure correction amounts obtained by the reduction maps in the same command current position.

Hydraulic pressure control apparatus

A fluid pressure control apparatus for controlling a solenoid valve to increase and decrease a fluid pressure by varying a valve opening degree includes a controller to control the fluid pressure by varying a command current for driving the solenoid valve. The controller calculates a hysteresis correction quantity to reduce a hysteresis effect of a hysteresis characteristic of the fluid pressure outputted from the solenoid valve with respect to the command current varied in an increasing direction and a decreasing direction, and varies the command current to control the fluid pressure to a target pressure in accordance with the hysteresis correction quantity. The controller calculates the hysteresis correction quantity in accordance with a turn-to-turn variation quantity determined from a current difference between a first command current value at a first changeover of a varying direction of the command current from one of the increasing and decreasing directions to the other and a second command current value at a second changeover of the varying direction of the command current before the first changeover.

Growing community of inventors

Fuji, Japan

Yoshio Morita