Sliding mode control for two-input and two-output (TITO) looper systems

A robust sliding mode controller is designed for looper systems in hot strip mills in order to solve the problem of tension and height decoupling control. The original uncertain looper system was first transformed into a standard form for facilitating the design of the controller. Then based on the transformed system, an improved sliding mode control strategy is proposed. This kind of control action has robust performance, which is suitable for complex looper systems. For the particular mode, the corresponding sliding mode reaching condition of the controller is obtained, and gives the proof of stability. The design control strategy of sliding mode control for looper systems is introduced to decouple the system and improve control effect. At last, simulation results show that the proposed scheme can get well performance under various conditional.