Study On Gauge Robust Control System Of Reversible Cold Strip Mill

The accuracy of strip gauge and the strip flatness are two quality targets of strip production. At present, they have huge advancement with the development of rolling theory, control theory, and artificial intelligence theory and with their application in the rolling process. However, It's still one of researching hotspot problems in strip gauge control accuracy.At present, many scholars have deeply studies analysis and synthesis of dynamic math model of gauge closed-loop control system of the hydraulic cylinder displacement, while few people studies that of inner roll-gap closed-loop control system. The paper introduces the conception of roll-gap strip mill stiffness to strip mill that adopts inner roll-gap control. Establishes dynamic math model of inner roll-gap closed-loop gauge control system using mechanism analysis method. These provide theory basis for inner roll-gap gauge-control systems of strip mill.In order to decide if the above dynamic math model can describe practical system, robust and PID complex control is applied to the position inner loop in the light of the parameter uncertainty even the structure uncertainty of the position inner of the gauge control system. The Simulation shows that that applying robust and PID complex control to the position inner loop can eliminate the effect of the parameter uncertainty even the structure uncertainty of the controlled object and disturbance.H2 Robust control based on Smith predictor is applied to the gauge control system in view of time deiay of the gauge systems. Model of Smith predictor is revised in time in the light of vary of delay time with rolling speed. There is still error in model revised, in view of this case simulation is studied and stability is analyzed.