Patent ID: 9079609
Filing Date: 2015-07-14
Classification: B62D

Abstract:
1. A hydraulic power steering system that generates a steering assist force by supplying hydraulic fluid from a hydraulic pump to a power cylinder, which is coupled to a steering mechanism of a vehicle, via a hydraulic control valve that is not mechanically coupled to a steering member, comprising: a pump driving motor that is used to drive the hydraulic pump; a valve driving motor that is used to control an opening degree of the hydraulic control valve; a rotation speed detection sensor for detecting a rotation speed of the pump driving motor; a rotation speed command value setting controller for setting a rotation speed command value that is a command value of the rotation speed of the pump driving motor; a pump driving motor drive controller for executing drive control on the pump driving motor such that the rotation speed detected by the rotation speed detection sensor is equal to the rotation speed command value set by the rotation speed command value setting controller; an opening degree command value setting controller for setting an opening degree command value that is a command value of the opening degree of the hydraulic control valve; an opening degree command value correction controller for correcting the opening degree command value, which is set by the opening degree command value setting controller, on the basis of a deviation between the rotation speed command value set by the rotation speed command value setting controller and the rotation speed detected by the rotation speed detection sensor; and a valve driving motor drive controller for executing drive control on the valve driving motor on the basis of the opening degree command value obtained through correction by the opening degree command value correction controller.