Tension control in hot strip process based on LMI approach

A robust controller is designed for looper systems in hot strip mills in order to solve the problem of tension control. This kind of control action has robust performance, which is suitable for complex looper systems. For the particular mode, the corresponding existence condition of the controller is obtained by applying Lyapunov function approach and the linear matrix inequality (LMI) technique. At last, we compare the performance of conventional H∞ controller based on Riccati with the proposed robust controller based on LMI method. Simulation results show that the proposed scheme can get well performance under various conditional.