Stabilizer control apparatus for use in motor vehicles

Claim 1

A control apparatus for use in a motor vehicle having at least a left-side wheel and a right-side wheel, comprising: elastically twistable stabilizer means provided between said left-side and right-side wheels of said motor vehicle; hydraulic pressure cylinder unit means coupled between one end portion of said elastically twistable stabilizer means and one of said left-side and right-side wheels, said hydraulic pressure cylinder unit means having at least one cylinder body and one piston dividing the space within said cylinder body into two chambers and slidably movable in said cylinder body so as to be expandable and contractable in accordance with slidable movements of said piston; hydraulic pressure generator means for generating a hydraulic pressure; hydraulic pressure actuator means including change-over valve means and coupled between said hydraulic pressure generator means and said hydraulic pressure cylinder unit means to control hydraulic pressures in said two chambers of said cylinder body using the hydraulic pressure generated by said hydraulic pressure generator means so as to allow adjusting a position of said piston, the position of said piston in said cylinder body determining the twisting amount of said stabilizer means; steering angle sensor means for sensing a steering angle of said motor vehicle in response to a rotational movement of a steering wheel of said motor vehicle and generating a signal indicative of the sensed steering angle; position sensor means adapted for sensing the position of said piston in said cylinder body and generating a signal indicative of the sensed piston position; first control means responsive to said steering angle signal and said position signal from said steering angle sensor means and said position sensor means to determine a predetermined stable condition of said motor vehicle on the basis of said steering angle signal and to obtain a neutral position of said piston taken under the condition that said motor vehicle is in said predetermined stable condition, said neutral position thereof being sensed by said position sensor means; and second control means responsive to said steering angle signal to determine a turning state of said motor vehicle on the basis of said steering angle signal and to determine a target piston position with respect to the obtained neutral position of said piston in accordance with the degree of the vehicle turning state, determined by said steering angle signal, in response to the determination of the vehicle turning state, said second control means outputting a control signal to said hydraulic pressure actuator means so that said piston is controlled to assume the determined target piston position.