| 摘要 |
PROBLEM TO BE SOLVED: To provide a hydraulic power steering system that can suppress variation of steering assist force caused by variations in a rotation speed of a pump driving motor to enhance a steering feeling.SOLUTION: A first valve opening correction value computation unit 61 computes a correction value (first valve opening correction value &Dgr;&thetas;1) for the absolute value |&thetas;*| of a valve opening command value &thetas;* on the basis of a rotation speed deviation &Dgr;V(=V*-V) computed by a rotation speed deviation computation unit 75 in a pump driving motor control unit 70. A second valve opening computation unit 62 computes a correction value (second valve opening correction value &Dgr;&thetas;2) for the valve opening command value &thetas;* on the basis of a sign of the valve opening command value &thetas;* and the first valve opening correction value &Dgr;&thetas;1. A correction value addition unit 63 adds the second valve opening correction value &Dgr;&thetas;2to the valve opening command value &thetas;* set by the valve opening command value setting unit 52. |
