Patent ID: 8200393
Filing Date: 2012-06-12
Classification: B62D

Abstract:
1. A vehicle steering apparatus for changing an angle of a steered wheel of a steering system of a vehicle in accordance with operation of a steering wheel by a driver, the vehicle steering apparatus comprising: a variable transmission ratio device including a motor, the variable transmission ratio device changing the transmission ratio between the steering wheel and the steered wheel by superimposing a first steering angle of the steered wheel based on a turning angle of the steering wheel, on a second steering angle of the steered wheel based on activation of the motor; a steering force assist device, which is different from the variable transmission ratio device, for applying an assist force that assists a driver steering operation to the steering system; and control means, which controls actuation of the steering force assist device, wherein the control means calculates a basic assist component for controlling the steering force assist device, corrects the basic assist component to counteract oversteer or understeer, calculates a compensation component based on a differential value of a steering torque generated in the steering system, and computes a target assist force for controlling the corrected steering force assist device by superimposing the basic assist component and the compensation component on each other, and wherein the control means increases the compensation component based on the differential value of the steering torque when the variable transmission ratio device is being actuated.