Funnel-control for electrical drives with uncertain parameters

A time-varying control strategy for speed control of a two-mass flexible servo system with uncertain parameters is investigated. The control strategy is based on a funnel concept, which has only been developed for systems with relative degree one, therefore a direct use in most industrial applications is inhibited. To be applicable for systems with higher relative degree - as the considered servo system - a state-feedback like extension is necessary. The problem of choosing feedback coefficients is solved such that a minimum-phase state-feedback is guaranteed. Especially for electrical drive systems stability is shown, even if not all states are fed back, what reduces the amount of measurement theoretically. However the performance is improved if all states are used for the feedback signal. The goal is to control the speed of a load-mass in the sense of tracking a given reference signal by a prescribed decay of the control error