Patent ID: 8234041

Claim:
An electric power steering controller comprising: a steering torque sensor detecting a steering torque applied to a steering system from a steering wheel; an electric motor connected to the steering system to generate a steering assist torque; means for calculating a target value of the steering assist torque generated by the electric motor, based upon the steering torque detected by the steering torque sensor; means for calculating a correction value of the steering assist torque based upon a transmission characteristic of the steering assist torque from the electric motor to a tire; and means for controlling the steering assist torque generated by the electric motor so as to make the target value of the steering assist torque equal to a correction target value corrected by the correction value; wherein the means for calculating the correction value calculates a correction value for a difference between a rotational angular velocity of the electric motor and a steering angular velocity of the tire to be closer to zero when a relation between the rotational angular velocity and the steering angular velocity is converted into an angular velocity in which both the rotational angular velocity and the steering angular velocity can be compared.