Study On Intelligent Optimization And Intelligent Control For Electromagnetic Direct Chill Casting Parameters

Electromagnetic Direct Chill Casting is a strong nonlinear and complexity process with high temperature. It is very difficult to build mathematical model for electromagnetic direct chill casting process, because that some important signal inside ingot can not been measured online. The artificial intelligence(AI) is used to solve some problems of the optimization of the electromagnetic direct chill casting process. An obvious merit of the proposed method is to incorporate the rich experiences of experts and engineers into the optimization without modeling the system or the process in a mathematical view.The application of the artificial intelligent technology, such as fuzzy mathematics, artificial neural network, expert system and genetic algorithm to the optimization control of the electromagnetic direct chill casting processes is considered in this dissertation. The purpose of my study is:to combine intelligent control and intelligent optimization into the distribute control system of electromagnetic direct chill casting; to build new intelligent control system for electromagnetic direct chill casting process; to exploit new technique of intelligent control and intelligent optimization; to boost productivity of electromagnetic direct chill casting field.The uncertain information of electromagnetic direct chill casting process can be handled by using the fuzzy control method. The information with non-value form can be used to construct the rule base system. Based on the idea of fuzzy and artificial neural network method, the express system can promote the applications of the expert system to some extent. An outstanding advantage of the artificial neural network method is that it can pass the sample learning, and then accurately emulate every kind of non-linearity. Genetic algorithm can simulate the law of nature—survival of the fittest. So it is used to find the global optimum parameter.The study results in this dissertation are listed as follows:1) The industrial scale of the electromagnetic direct chill casting factories in our country is small, and the requirement of the control performances is high, so the distribute control system(EPM2006),with low cost and high capability, is developed in the optimization control of electromagnetic direct chill casting process. The layer construction is adopted in the hardware design, and the modularization programming method with the object orientation is utilized in the software design. The EPM2006 distribute control system is independently developed and manufactured with the convenient, flexible, easy, simple, and credible characteristics. It has achieved the advanced level in total technical viewpoint.2) The new construction of intelligent control is made. The electromagnetic direct chill casting processes intelligent control system and the distribute control system are combined to possess advanced control functions.3) Combining intelligent control into the traditional control system, it has gotten some good results to control liquid level of casting mold by expert-fuzzy control; to control cooling water by self-adjust-parameter fuzzy control; to control tundish temperature by PI-fuzzy control.4) Micro-expert system has been built to diagnose malfunctions all through the electromagnetic direct chill casting process. The leak-out signal can been detected to avoid disaster by soft-sensing.5) The neural network model is established to estimate ingot crack tendency. Theprocess is modeled by using the improved BP learning algorithm, and the neural network model trained by the production datum has high estimate accuracy. The maximal relative estimate error is 13.9%, and the minimal one is 0%.6) The global optimum parameters have been gotten by optimizing crack prediction model with improved genetic algorithm. It helps to improve the ingot quality and reduce the reject rate.The economic benefits of these applications are obvious by increasing the production and reducing the energy consume.The research on the application of artificial intelligent method in the electromagnetic direct chill casting processes is still developing. And it needs urgent improvement. Therefore, in my opinion, researcher could consider the research in the following aspects:to perfect theoretical results, to further study the material forming processes, to perfect artificial intelligence(AI) theory, to apply the intelligent system in practice.