Patent ID: 7183738

Claim:
A motor control device for driving, based on a speed command signal, a motor coupled to a mechanical load associated with a mechanical system having a resonance frequency and an anti-resonance frequency, the motor control device having in a speed control loop detection speed of the motor, and comprising: a speed control means for outputting a drive command signal for the motor so as to make the speed of the motor conform to the speed command signal, based on a signal indicating the difference between the speed command signal and the detection speed of the motor; and a filter inserted in series with the speed control means in the speed control loop, the filter having frequency-dependent phase lag characteristics divided into a high frequency domain, a low frequency domain, and an intermediate frequency domain between the high frequency domain and the low frequency domain, and in which the gain KL in the low frequency domain is larger than the gain KH in the high frequency domain, and in which the phase is delayed in the intermediate frequency domain; wherein the speed control means includes a proportional controller for multiplying input by a proportional gain KP and outputting the result, as well as an integral controller for adding the value of the input multiplied by the proportional gain KP, and the integral of the input multiplied by an integral gain KI, and outputting the result; and filter settings are adjusted so that frequency the phase of the filter is delayed at frequency domain between the resonance frequency and the anti-resonance.