Modeling and receding-horizon control for looper-interconnected systems

By investigate how the rolling speed of downstream stands affects on the looper tension system, and analyzing the characteristics of hot strip stands working in cooperation, we build the model for the looper interconnected system, and develop separate controller for each looper system based on distribution control. To deal with the strong coupling between the height and tension in a looper system, we employ the multiplex control strategy based on the receding horizon theory. After all the subsystem-controllers are obtained sequentially in one cycle, the system is updated in time. The decoupling problem is transformed into a compound problem of disturbance rejection and comprehensive optimization, according to the H-infinity control theory. Simulation results show the effectiveness of this strategy in improving the decoupling effect and the control performance.