Suppression of torsional oscillations in a high-performance speed servo drive

This paper deals with the problem of mechanical resonance in modern servo drive systems having the speed control loop bandwidth and resonance frequency above 100 Hz. To enable the extension of the range of stable gains in the presence of flexible coupling, a simple and straightforward modification of the speed loop controller is proposed in order to augment the performance of present speed controllers and to make them accordant with mechanical structure suffering from the compliance problem. This paper is comprised of the analytical considerations, straightforward design guidelines, and results of experimental verification obtained by an experimental setup with the elastically coupled 7-N m synchronous servo motor and mechanical resonance frequency of 160 Hz.