Patent ID: 9533705
Date: 2017-01-03
CPC Classifications: B62D

Claim:
1. A vehicle steering system for a vehicle having a steering wheel mechanically connected with wheels so as to maintain a relative relationship between the steering wheel and the wheels, comprising: an electric motor that applies an assist torque for assisting the steering of the steering system of the vehicle; a steering torque detecting unit that detects a steering torque required for steering of the steering system; a steering angle detecting unit that detects a steering angle according to the steering system; a traveling state detecting unit that detects whether or not the vehicle traveling straight; and a control device that controls driving power of the electric motor based on vehicle information including the steering torque and the steering angle to impart the assist torque to the steering system, wherein the control device includes: an integrating unit that calculates an integrated torque value which is an integrated value of the steering torque; and a unidirectional drift controlling unit that performs a unidirectional drift control over the driving over of the electric motor so as to cancel the unidirectional drift behavior of the vehicle, based on the integrated torque value and mapping information of the driving power of the electric motor relative to a change in the integrated torque value.