Application of Mixed Sensitivity in Electro-hydraulic Load Simulator

Because some parameters are uncertain in loading system of electro-hydraulic load simulator, the controller designed by classical control theory has disadvantages such as dependency on model and weak robustness. Robust controller is designed by mixed sensitivity H_∞ approach through choosing suitable weighted functions. It´s solved through linear matrix inequality algorithm. It´s testified by experiments that robust controller can satisfy robust stability and robust performance when spring stiffness changes. It also can eliminate superfluous force and improve passive loading performance with compensation of structure invariance principle.