The coupling model and robust controller design of vertical system in rolling mills

The mathematical model of electromechanical-hydraulic coupling system in rolling mills, which includes the servo hydraulic system, the mill housing system and rolls system, is established with the consideration of influence on dynamic behavior by nonlinearity and parameter uncertainties. Then the closed-loop gauge control system in frequency form is obtained. The robust controller design is introduced by using quantitative feedback theory, based on several system performance indexes. The influence on system stability by the performance of hydraulic automatic gauge control system is discussed, the reference signal tracking behavior and control performance comparison with PI controller is made via simulation case study, to show the advantage of the proposed control algorithm.