Research On Fuzzy-PID Control Method For Continuous Casting Mould Level

In the modern production of continuous casting mould, with the automation level increasing of the factory, the requirements about the reliability and the foundry quality have become more and more strict, and the requirements of hydraulic level control precision have also become higher.Mould level control is an important part during the metallurgy continuous casting moulds. The level fluctuation may lead to protective dregs and the impurities get into the steel water, which could affect the quality of the steel or even cause the steel water to leak and overflow. So the level must be controlled within a reasonable range. However the mould level system has the characteristics of the non-linear and time variability, there are many unsure disturbing factors in this system so the precise mathematical model can not be proposed. The conventional control method could not be satisfying with the requirement of higher automation and quality. In recent years, many intelligent level control methods appeared to improve the controlling effect of the mould level. This paper mainly researches the design and application of the Fuzzy-PID complex compound adaptive control method for the continuous casting mould level control in Baotou steel corporation.The Baotou steel corporation's continuous casting electric configuration adopts the distributed control system which is composed of PLC. The structure of the program is optimized by simplifying software frame so the CPU928B can work in the best state. This paper introduces the mould controller's actual hardware system and proposes the method of the mould level Fuzzy-PID control. By analyzing the actual software system framework, membership function and fuzzy rule the adjustive method was provided for the differential coefficient and the integral time constant. The Fuzzy-PID compound adaptive controller is adopted in this system. By analyzing the operation result of fuzzy control the K_P can keep in an ideal area so the requirement of control system for the mould level can be satisfying.