Study On The Decoupling Control Of Gauge And Flatness In Strip Cold Rolling Mills

In our country, self-research strip mill of flatness automatic control system is relatively less, while the integrated automatic control system of gauge and flatness is almost blank. On the one hand, it's because of imperfect shape meter, on the other hand, the strong coupling relationship between gauge and flatness is difficult to determined, and this increase difficulty to realise integrated control between gauge and flatness. In the background of practical engineering project, this paper further studies coupling mechanism of gauge and flatness also dynamic mathematical model of control system of gauge and flatness is derived, and intelligent control theory is applied to gauge and flatness control. Simulation results show that intelligent control applied to rolling process is feasible.Firstly, coupling models of strip gauge and flatness expressed by crosswise tensile stress and crown are derived respectively. Basis for control theory and engineering practice, under the case of having not a significant impact on the gauge and flatness, the models of the cold rolling hydraulic pressure depress the automatic position control system and the hydraulic automatic roll-bending force servo control system are equivalent simplified. Then equivalent time constant is given in the Simulation experiment. This provides a good model foundation for further study on the integrated decoupling control of gauge and flatness.Secondly, basis for above dynamic mathematical model of gauge and flatness, the coupling influence between strip gauge and flatness is analyzed deeply. In the foundation of research on various decoupling control principle, the decoupling control method is put forward which is combined with the feedforward compensation decoupling and the gain self-adaptive fuzzy PID control. The results show the decoupling effect of the control method is obvious, and the control precision is somewhat increased.Lastly, in view of the non-unique model parameter of gauge and flatness, the best application scope of plastic rigidity parameter is proposed when the neural network is decoupling. Meanwhile, the control method of diagonal recurrent neural network (DRNN) tuning PID parameter is studied after the system decoupled, and has been applied to the decoupling control system of gauge and flatness, enabling the control system to have the faster response speed. It provides a new method to solve gauge and flatness integrated control effectively.