Patent ID: 8476851
Filing Date: 2013-07-02
Classification: H02P

Abstract:
1. A motor magnetic pole position correction method for correcting a relative positional relationship between a movable element position of a direct drive motor and a movable element position detection value detected by a position detector attached to the direct drive motor, the method comprising: a step of preventing movement of a movable element of the direct drive motor by a mechanical brake; a step of inputting a position command that designates a position different from a present value as a commanded movable element position of the direct drive motor; a step of detecting a torque command value of the direct drive motor; a step of determining a magnetic pole position correction value based on a comparison between the detected torque command value and a predetermined threshold value; a step of storing the determined magnetic pole position correction value in a memory; and a step of performing motor control using an electrical angle offset value obtained based on the magnetic pole position correction value stored in the memory.