Research On The Control Methods Of LF Alloy Weighing System

Alloy weighing system plays an important role in Ladle Furnace production process.The product quality depends on the alloy weighing whether to strictly follow the rules of proportion.As a result,a precise control of the alloy weighing system is needed.But the level of automation of most alloy weighing system is low,it causes that a lot of material resources are wasted.Therefore,it is imperative to make researches on dynamic alloy weighing with high credibility,high efficiency and simple architecture.In this thesis,the process of Ladle Furnace craft and the component of equipment are introduced by consulting a great deal of literatures in the country and abroad,the present research development of Ladle Furnace alloy weighing system is summarized.This thesis takes a 120t Ladle Furnace steel computer control system as the actual research background.From the whole structure of alloy weighing system,electromagnetic vibration feeder which is a major section of alloy weighing system is studied,its mathematical models is established for that the dynamic alloy weighing control need it,and also the model is validated by simulations.A method based on Iterative Learning Control is used for the controller designing,according that the alloy weighing system has the characters of nonlinear,high inertia and random,besides,the control process is a repeating one.Precisely,the method is a PD type open-closed loop iterative learning.The alloy weighing process can respond rapidly and accurately by using the controller.We find the simulation result is bad when the parameters of the system is changed.Then we use fuzzy controller to improve the effect of the iterative learning controller.The implementation platform of the Ladle Furnace alloy weighing system is designed by the process control requirements.And the flow chart of alloy weighing program is designed.We also program iterative learning into our project.In the end,on the basis of summarizing the whole research work,the trend for the future development of Ladle Furnace alloy weighing system is pointed out.