The Fuzzy Modeling Based On LSSVM And Application In Casting Equipment Control

Fuzzy Identification is to identify the fuzzy model of the system from the measured values of system inputs and outputs, using fuzzy set theory, it has a very wide range of applications in the field of nonlinear system identification. However, the existing identification algorithm is still facing the problems of how to avoid the curse of dimensionality and improve the model generalization capability. Fuzzy Model Identification includes structure identification and parameter identification. One of the most important is the structure identification, and it has not formed a theory on the structure identification. Moreover, there are still many difficulties in the application of fuzzy model identification in actual industrial processes. One of reasons is the huge rule base generated by the traditional identification methods, and consumption of identification calculation. Therefore, the main purpose of this paper is how to design a simple and effective identification algorithm, how to reduce the identification algorithm computing complexity.In this paper, we do some research on TS fuzzy modeling based on least squares support vector machine (LSSVM), and proposed a method of LSSVM-based fuzzy model control. Then we applied it in advanced casting equipment constant casting control system and mainly done the following work:1) For the high computational complexity problem in fuzzy modeling method based on standard support vector machine, the introduction of the LSSVM with equation constraints, significantly improved the efficiency of modeling.2) The structure of fuzzy model is identified using the LSSVM algorithm; the sparse support vectors are gotten through the pruning algorithm without changing the training parameters; the Fuzzy space is divided based on the number of support vectors. It simplifies the structure of the fuzzy model, and promotes its application.3) The LSSVM fuzzy model is introduced into the internal model control, and used as the system's internal model. The inverse model controller is designed according to this modeling method.4) A constant casting control system is designed. A simulation model is built after the analysis of features of the constant casting pressure control system. The simulation results show that quantitative casting surface pressure systems, internal model control method based on of LSSVM fuzzy model has certain advantages in the control precision and anti-interference capability.