Enhancing Performance through Multivariable Weighting Function Design in H-Infinity Loop-Shaping: With Application to a Motion System

The quality of model-based controllers hinges on a careful specification of performance and robustness requirements. In typical norm-based control designs, these performance and robustness requirements are specified in a scalar optimization criterion, even for complex multivariable systems. This paper aims to develop a novel and systematic approach for the formulation of this optimization criterion for complex multivariable systems. Hereto, characteristics of the underlying system are exploited. In contrast to pre-existing approaches that typically lead to multiloop SISO weighting functions, the proposed approach enables the design of multivariable weighting functions. Experimental results confirm that the proposed procedure significantly improves the performance of an industrial motion system compared to earlier approaches.