Motor drive apparatus and method of controlling the same

摘要

A positional deviation reading sampler reads or samples a positional deviation between a target position inputted from an external device and an actual position of a motor. A position control calculator converts the positional deviation into a speed command. A speed control calculator receives a speed deviation between the speed command and an actual speed, and converts this speed deviation into a torque command to drive the motor. The position control calculator, having a function of switching a sampling interval in accordance with a level of the positional deviation, determines an optimum sampling interval for the positional deviation reading sampler. The speed control calculator performs the open-or-close control of the sampler in such a manner that the sampling interval of the positional deviation reading sampler is reduced with reducing positional deviation. With above arrangement, it becomes possible to stably drive the motor in its moving condition and position the same accurately and responsively in its stationary condition.