Robust mixed-sensitivity H∞ control for a class of MIMO uncertain nonlinear IPM synchronous motor via T-S fuzzy model

This article presents robust mixed-sensitivity H∞ output feedback controller by using loop shaping with regional Pole Placement for a class of MIMO uncertain nonlinear system. In order to design of controller first via Takagi and Sugeno´s (T-S) fuzzy approach the nonlinear dynamic is represented by several linear sub systems. After that, loop-shaping methodology and Mixed-sensitivity problem are introduced to formulate frequency-domain specifications and a systematic design of weighting matrices is presented. Then a regional pole-placement output feedback H∞ controller is employed by using linear matrix inequality (LMI) approach for each linear subsystem. Parallel Distributed Compensation (PDC) is used to design the controller for the overall system and the total linear system is obtained by using the weighted sum of the local linear system. Several results show that the proposed method can effectively meet the performance requirements like robustness, good load disturbance rejection responses, good tracking responses and fast transient responses for the 3-phase interior permanent magnet synchronous motor (IPMSM) system. In addition, the superiority of the proposed control scheme is indicated in comparison with the feedback linearization and the H2/H∞ controller´s methods.