Research On Combustion Control Of Reheating Furnace Used For Steel Hot Rolling Based On Closed Loop Hierarchical Adaptive Fuzzy Control

The reheating furnace used for steel hot rolling is a typical complicated industrial object, having the characteristic of multi-variable, time-varying, nonlinearity, strong coupling, long time inertia, pure delay and so on. Because it's burning and heat conducting principle is so complex that it is too difficult to model accurately. This condition limits the application of classical and modern control theory to accurately control it greatly.Classical control theory is the initial form of intelligence used in control. With the prosperous development of intelligent control theory, great innovation happened to the control theory. This carve out a new way to raise the control level over the complicated industrial object hard to model. Therefore, for this kind of complicated objects as reheating furnace used for steel hot rolling, raising their intelligent level of control is the most effective method and the inevitable trend to raise their control level.According to the hierarchical control principle: with the increase of intelligence, the accuracy decrease, the closed loop hierarchical adaptive fuzzy control method applied to the combustion control of reheating furnace used for steel hot rolling was proposed in this paper. In this method the classical control method was used as the bottommost layer to control the object accurately and directly. Based on this control layer the method of the closed loop fuzzy gain scheduling was used in the upper control layer of the second, by introducing the inner information of the closed loop control system to adjust the bottom controller parameters to optimization. The stability supervision control was used as the third control layer of hierarchical control structure to improve the performance of stability and dynamic adjustment.In this paper, applied the SIMULINK simulation tool of MATLAB software, the simulation model based on the closed loop hierarchical adaptive fuzzy control system was established. By running simulation, the curves under the control of different layers were gained. The reason that the control performance get better with the increase of control layer was analyzed. Besides this, the reason that the stability supervision control improve the performance of stability and dynamic adjustment was analyzed.By simulation experiment, the supposing of using the control method of closed loop hierarchical adaptive fuzzy control to control the combustion process of reheating furnace used for steel hot rolling in this paper gained the effective experimental verification.