Patent ID: 7810608

Claim:
A steering apparatus for a vehicle which includes a steering wheel rotated by a driver, a steering shaft which rotates together with the steering wheel, a steering unit which mutually connects the steering shaft and steerable wheels of the vehicle and steers the steerable wheels in accordance with rotation of the steering shaft, and an electric motor which applies a predetermined torque to the steering operation of the steerable wheels, the steering apparatus comprising: a steering angle detection unit which detects a first steering angle of the steerable wheels which are steered in accordance with rotation of the steering wheel based on a first reference point for maintaining the vehicle in a straight travel state; a side-slip-angle detection unit which detects a side slip angle of a body of the vehicle generated when the vehicle is in a turning state; a reference-point calculation unit which calculates a second reference point which changes in accordance with the detected side slip angle of the vehicle body and is used for determining a second steering angle for causing the vehicle to turn while reducing an influence of a lateral force on the turning state of the vehicle, the lateral force being generated in the vehicle due to the side slip angle of the vehicle body; a steering angle conversion unit which converts the first steering angle of the steerable wheels detected by the steering angle detection unit based on the first reference point to the second steering angle based on the second reference point; a reaction-torque calculation unit which calculates a reaction torque based on a predetermined relation with the second steering angle, the reaction torque acting in a direction for causing the second steering angle to coincide with the second reference point; and a drive-control unit which controls rotating and driving of the electric motor so as to generate the calculated reaction torque.