The Estimate Based On Kalman-Filter And Analysis Of Key Parameters In Counter-Gravity Casting Precise Control

Counter-gravity casting is a ideal method to obtain large high-quality components, One of its main features is to make the liquid metal under pressure crystallization and solidification, to improve performance and quality of castings. Existing anti-gravity casting methods more emphasis on the control precision of pressure and the process of casting to ensure the solidification process requirements, but because of nonlinear characteristics Of the system ,The dynamic process of filling mold doesn't further research .Along with the development of technology and small precision components in the gravity casting, and puts forward the requirements of the anti-gravity precision casting, It requires the ability to precisely control the rate of rising liquid filling dynamic process ,However, due to the high temperature of molten metal is difficult to measure fluid velocity, we need to study its control method, to solve the problem of filling the speed control. On this point, this article mainly do the following job.(1) Through the research of casting process, analyzes the casting pouring process from control perspective qualitative. According to counter-gravity precision casting problems, establish the control process and control object and selection process parameters to make whole process control process smoothly.(2) Conducted a modeling analysis and experimental verification of the dynamic process of counter-gravity casting, because of this dynamic model is a complex nonlinear system with a lag, existing casting methods can not precisely control the speed.(3) For the application of control theory to address the problem of counter-gravity precision casting, make S field research and linearization of its dynamic process S field and carried out and for linearization of its dynamic process to get the control description of counter-gravity casting process.(4) kalman filtering method is a kind of good dynamic measurement method for target tracking and the forecast, and its valuation is minimum variance estimation. Considering the system has many noise interferences, so using kalman filtering method to design state observer of the system. Analysis of kalman filtering recursive process, get recursive formula of kalman filtering of counter-gravity casting, and simulation analysis, explain its feasibility to solve counter-gravity precision casting for the speed precision control problemMain results of this paper is that Control methods are introduced into the casting process problems to Clearly describe the control process of counter-gravity casting with nonlinear characteristics, Through the Kalman filter method realizes the real-time estimates of key parameters, and use the control method to solve the counter-gravity casting process issues.