Decentralized overlapping control for speed and tension in reversing cold-strip mill
可逆冷带轧机速度张力系统的分散重叠控制

To tackle the coupling between the speed and tension and to coordinate their control, we propose a decentralized overlapping control strategy for a reversing cold-strip rolling mill. The original state space is expanded into multiple decoupled overlapped subsystems based on the principles of inclusion and overlapping decomposition. The control law for each subsystem is developed by applying the linear quadratic(LQ) optimization and the sequential control method. By contracting the designed control laws to the original state space, we obtain the desired controller for the original system. A simulation is carried out on the speed and tension control system of 1422mm reversing cold-strip mill. Results show that the proposed strategy reduces the coupling between the speed and tension, realizes the coordinated control for main rolling, the left and right coilers, improves the dynamic performance of the tension control system and raises the precision of the tension during acceleration and deceleration.