Research On Application Of Compound Control Strategy In Automatic Gauge Control Of Hot Rolling

The development of hot rolling technology needs to meet the needs of social production,but the current control level is at a turning point.For the sudden and complicated problems that appear in the rolling process of hot rolling mill,it is difficult to achieve the ultimate control purpose if general control methods are applied to this.The thickness of the strip is an important feature in the hot strip production,and its accuracy directly determines the quality of the finished product.This paper takes the1700 asp hot rolling line of Angang as the control application background.In order to better adapt to the production of steel rolling and make up for the shortcomings of traditional control methods,a composite control strategy is proposed,which is embodied in the application of hardness feedforward automatic gauge control system(KFF-AGC)and nonlinear PID control in the monitoring automatic gauge control system(MN-AGC),focusing on solving the thickness in the process of strip rolling.Through a large number of simulation and real-time on-line application,it is shown that the composite control strategy can greatly improve the strip thickness accuracy.The experimental results are as follows:(1)The research status of Gaugemeter Automatic Gauge Control(GM-AGC)and MN-AGC at home and abroad is analyzed.The basic working principles and application algorithms of each are introduced,and the important role in the automatic thickness control of hot strip rolling is explained.At the same time,the limitations of the system in the entire rolling production process are pointed out.(2)In view of the positive feedback phenomenon in the GM-AGC control process and the influence of temperature change(hardness change)on the thickness of the incoming material outlet,the hardness feedforward AGC control strategy based on the fact of temperature change is described in detail,and it is applied to each stand of rolling system,which plays a good role in reducing the thickness difference caused by hardness fluctuation.(3)Use the MN-AGC system to realize the monitoring and correction of the thickness control system.Considering the pure lag between the final stander and the thickness gauge and the limitation of traditional PID for the control of the complex rolling process,the non-standard is introduced in the monitoring AGC.Linear PID control algorithm plays a role in improving the response characteristics of the system.This paper proposes a compound control strategy based on the analysis of AGC in hot strip rolling.A large amount of simulation and experimental data show that this strategy has a good adjustment effect on hot strip thickness control.There are also certain improvements in the thickness control application algorithm.Therefore,this control strategy has a strong application prospect.