Research And Application On Reversible Single Stand4-high Cold Rolling Mill Gauge Control System

The accuracy of strip gauge is one of two major quality control guidelines. It is especially important to increase the strip quality in the fierce competition of in and abroad market economy. The gauge control is the key technology in the field of strip rolling and it is developing fast in the recent years. Based on the 300mm reversible single stand4-high cold rolling mill gauge control system, a comprehensive gauge control strategy is developed and applied to field production. The affection of integration time and sampling time on the system performance is studied in such delay system. The main work is as follows:(1) On the basis of collecting and understanding literatures in and abroad, the author analyzes the basic theory of strip mill gauge control and the characteristic of modern reversible single stand 4-high cold rolling mill.(2) Taking the 300mm reversible single stand 4-high cold rolling mill gauge control system as the research object, its equipment and process parameters are introduced and a computer control system which is based on the PLC and FM458 of SIEMENS is developed, and a relevant description of the system's network configuration, hardware configuration, software program is introduced.(3) A comprehensive gauge control strategy including feed forward AGC with varying locking value, monitor AGC with Smith Predictor using strip tracking, gauge meter AGC with mill spring mode is designed and applied to the control system successfully. Field application shows that the thickness of the control strategy has good usability and portability advantages.(4) An eccentricity compensation method based on fast Fourier transform is designed for roll eccentricity in strip rolling process. Preliminary simulation results show that this scheme can effectively improve the adverse effects of roll eccentricity.(5) Simulation analysis on proportional delay control systems and delay systems with inertia are carried out by Matlab simulation tool, the analysis gives the relationship between integration time, inertia time and the delay time., and a way about choosing integration time is put forward. And the impact on system performance of sampling time in discrete control system is also studied. The study theory is applied to monitor AGC system, and the simulation result shows that this type of integrator monitoring AGC control system has a fast response and a small overshoot, to meet production requirements.