Robust non- fragile guaranteed cost control for the looper system of hot strip rolling mill

Looper system of hot strip rolling mill is electro mechanic and hydraulic pressure system. Because of dynamic parameters uncertainties and complex structure, it´s very difficult to setup the model. However, its control performance has directly relative to the strip product quality. In this paper, robust non-fragile guaranteed cost controller is designed for looper system. For a class of uncertain discrete system, based on Lyapunov stability theory and linear matrix inequalities, a sufficient condition is presented for the existence of robust non-fragile guaranteed cost controller. Furthermore, this solvable approach for guaranteed cost controller is given by the feasible of linear matrix inequalities. This non-fragile guaranteed cost controller is applied to looper systems of hot strip rolling mill. Simulation results show the efficiency of the designing method.