Research On The Control Method Of Roll Eccentricity Compensation In Tandem Cold Rolling AGC System

In tandem cold rolling process,roll eccentricity,as the major factor causing periodic thickness deviation,not only directly affects the quality of the coil but also affects the economic benefits of cold rolled products.The compensation of roll eccentricity can effectively improve the accuracy of strip thickness,product quality and economic benefit.Therefore,it is necessary to study the methods of compensating control of roll eccentricity in cold rolling process.This thesis carries out the research on methods of compensation and control of roll eccentricity in Automatic Gauge Control(AGC)of cold rolling process.Main work and research results are as follows.(1)After introducing the process of cold rolling,the cold rolling production equipment and instrument configuration,the thesis analyzes the influence of roll eccentricity phenomenon of cold rolling production process and considers the interstand tension as the eccentricity signal source signals.Based on the comparison of the advantages and disadvantages of the tension control method in the production process,the relationship between the tension and the work roll gap is deduced.It is proved to be feasible to extract eccentricity signal aseccentricity compensation from the tension signal.The cause of the two kinds of roll eccentricity signal from a single backup roll is analyzed,and the mathematical model is established.(2)According to the actual situation in the factory,the mathematical model of AGC system is established.Repetitive control,a roll eccentricity based on repetitive control compensation system,is designed to solve the lag problems in the traditional way of using PID controller to compensate roll eccentricity(3)To get the roll eccentricity signal,the method of wavelet transform for signal processing of the strip tension is adopted.The tirals of compensation and simulation of eccentricity signals identified with the traditional PID controller and repetitive controller respectively have proved that the eccentricity compensation effect of repetitive controller is indeed better than that of PID compensation method.