A Study On Main Parameters Of Hydraulic AGC System In Rolling Mill And Modeling Validation

Hydraulic automatic gauge control (AGC) system is an integrated system which combines sheet strip, rolling mill, rolling technical, electrical system as well as control system. It is a profound and comprehensive topic to probe into hydraulic AGC system mechatronic hydraulic model to increase sheet strip accuracy in gauge.With the National Natural Science Fund and Hebei Natural Science Fund, based on Yanshan University 300 four-high rolling mill experiment, this study consists of the following aspects: To establish hydraulic AGC integrated model, analyze, simulate and revise the model, to shed light on improving the hydraulic AGC system, rolling mill practice and control strategy. To analyze the data of the rolling process systemically, involving FFT tool, parameters identification tool, parameters controlling and optimization tool, data analysis tool, signal processing tool, to research on the implementation approach and integrating methods of the kit, and the procedure call. To complete the software development of the virtual rolling mill simulation system and field roll milling experiment. To improve control strategy by verifying the theoretical model based on the Yanshan University 300 four-high mill experiment.The dissertation researches in-depth on the mechatronic hydraulic model, to analyze and simulate the system from the aspects of rolling mill practice and control strategy, to improve the hydraulic AGC systemic mathematical model.Base on the position closed-loop model and rolling force closed-loop model, the dissertation separately analyzes the performance parameters of fluid power key elements such as servo-valve, cylinder, control-piping and accumulator and its influence on hydraulic AGC systemic dynamic response and steady state accuracy. It analyses the influence of back pressure characteristics and supply pressure characteristic on the system. It comes up with the solutions of some common problems such as selecting servo-valve, designing screw-down cylinder independently, designing fluid power recruit hydraulic system. These research findings provide fluid power AGC system design staff with important theoretic references, give some hints to establish compensate strategy, thus it has important theory meaning and application value.The method of controlling system should be adjusted with the changes of rolling mill practice. The dissertation further studies on the controlling methods and their theory background, namely, establish controlling parameter optimization schemes and improve control system's performance according to the optimization objective. These research findings are important references to establish rolling mill practice and control strategy. Besides, they are the hot issues which specialists at home and abroad would like to discuss about comprehensively and lucubrately.The dissertation makes diagnosis on thickness error, based on conventional rolling mill mechanical analysis with modern data analysis and computational tools. FFT tool, wavelet analysis tool, parameter identification tool, relevance analysis, nonlinear regression analysis and signal processing tool could fulfill the data analysis functions, quantize the influence of roll milling system under different rolling mill practice on strip thickness. Thus the paper could offer references to the rolling mill practice establishment, hydraulic AGC system design. Besides, it gives clues to the research on theoretical model.