CONTROL DEVICE FOR POWER STEERING DEVICE FOR CAR

PURPOSE:To prevent the steering from becoming heavy at the time of steering hold by furnishing a control means to put the steering-back control out of effect in case the steering angular velocity is smaller than the specified value and is decremental during the steering-back in low speed operation. CONSTITUTION:In case the steering angular velocity theta is smaller than the specified value A1 during steering-back in low speed operation, the current impressed on a solenoid control valve 30 is put identical to the base current I as determined from the car speed v and the steering angle theta, and thereby decrease of the return control current IH is stopped. In case the steering angular velocity thetahas been decreased, the current impressed on the solenoid control valve 30 is increased gradually to the base current I, and thereby the assist force is controlled in the direction of enlarging, which should ensure that the steering will not become heavy at the time of steering hold. In case the return control current IH is calculated to the output current IO, change will be made gradually by the use of steering angle, so that there is no more steep change in the assist force, which should eliminate presence of foreign sense.