Improvement of Adaptive Property by Adaptive Deadbeat Feedforward Compensation Without Convex Optimization

This paper presents a novel adaptive feedforward (FF) compensation on the basis of the deadbeat control framework for the fast and precise positioning of high-performance mechatronic systems. Resonance frequency fluctuations in mechanisms generally deteriorate the positioning performance due to temperature variations, age deteriorations, and discrepancies among products. A robust controller design against the fluctuations, therefore, is one of important issues for industrial applications. In this paper, an adaptive deadbeat FF compensation is applied to provide nominal positioning performances under the parameter fluctuations. The proposed approach can adapt the FF compensator with no optimization calculation to shorten the adaptation interval period. In addition, saturation in the control input can be prevented during the adaptive compensation, on the basis of a linear matrix inequality technique. The effectiveness of the proposed approach has been verified by numerical simulations and experiments using a laboratory prototype of a galvano scanner, which is one of typical mechatronic devices for the fast and precise positioning in industrial applications.