Patent ID: 7325646

Claim:
An electric power steering apparatus comprising: a steering wheel; a steering shaft connected to the steering wheel; a steering angle sensor for detecting a rotational angle of the steering shaft as a steering angle; an electric motor for assisting, through a speed reduction gear mechanism, a steering operation performed by a steering mechanism connected to the steering shaft; and a motor resolver for detecting a motor electrical angle indicating a rotational angle of the electric motor, the electric power steering apparatus being capable of controlling the electric motor based on an absolute rotational position of the steering wheel, the absolute rotational position which is calculated based on the steering angle and the motor electrical angle, wherein: at least one of a speed reduction gear ratio of the speed reduction gear mechanism and the number of pole pairs of the motor resolver is set in such a manner that a calculated value, which is obtained by multiplying the speed reduction gear ratio of the speed reduction gear mechanism with the number of pole pairs of the motor resolver, represents a non-integer having a numerical value of the decimal place, and the electric power steering apparatus further comprises: an absolute rotational position specifying device configured to specify an absolute rotational position of the steering wheel from among plural possible absolute rotational positions that are obtained based on the steering angle and the motor electrical angle.