Feedback control method based on servomechanism speed estimating and processing to reduce residual vibration

Abstract

The paper presents a functional method for suppression of the two-mass system residual vibrations. The vibrations are excited due to the common effect of torsion plasticity and large moment of inertia of kinematical chain components. The described strategy is based on a mathematical model of servomechanism which is predicting the actual speed of the kinematical chain end-point. The estimated speed of the endpoint is consequently subtracted from the internally measured speed at the motor shaft and by means of weighting and phase shifting there is computed the correction signal which is ready to be used in conventional control structure and in this way to effectively damp the residual vibrations of the kinematical chain end-point. The method functionality was tested first in the numerical simulation of the servomechanism mathematical model and after that it was integrated into the existing cascade structure of the standard servo control unit Siemens Sinamics S120 and verified experimentally on the real system. The result both of the simulations and experiments on the real device, shown in the final part of the article, demonstrate the ability of this method to effectively damp the residual vibrations of the mechanism end-point.