ANGLE ERROR CORRECTION DEVICE AND ANGLE ERROR CORRECTION METHOD FOR POSITION DETECTOR

The invention provides an angular error correction device and an angular error correction method for a position sensor that allow estimating and correcting an angular error accurately. A position sensor detects the rotational position of an electric motor, and includes a periodic error uniquely determined in accordance with the rotational position. A current sensor detects current flowing in the electric motor. Using the rotational position of the electric motor, a frequency analysis unit analyzes the frequency of the current detected by the current sensor, and calculates an amplitude of a specific frequency component corresponding to the angular error. An angular error estimator estimates, as an angular error estimated value, the angular error formed from the specific frequency component on the basis of the amplitude calculated by the frequency analysis unit and the rotational position of the electric motor. Using the angular error estimated value, an angular error correction unit corrects the angular error for the rotational position of the electric motor detected by the position sensor.