Patent ID: 7248016

Claim:
A motor controller comprising: an inverter including plural switching elements that are subjected to PWM control to generate sine waves of plural phases; a motor including a stator coil supplied with the sine waves thus generated so that rotational magnetic field is generated in the stator coil, and a rotor that is rotationally driven by the action of the rotational magnetic field generated by the stator coil; a storage unit for detecting the sine waves of the respective phases generated in the inverter and storing a correction amount for each phase that is calculated on the basis of the detection result so that the sine waves of the respective phases are coincident with one another; and a correcting unit for correcting a PWM signal for carrying out the PWM control on the switching elements on the basis of the correction amount thus calculated, wherein the motor controller is implemented in a steering device for driving a motor on the basis of a steering state detected by a steering state detecting unit, and actuating a transmission ratio varying mechanism for varying the transmission ratio between a steering angle of a steering wheel and a turning angle of a steered wheel, or an auxiliary mechanism for assisting the steering force of the steering wheel.