Mould-Level Control System Of Continuous Casting Machine Based On Fuzzy PID

Regarding the liquid level control system of a continuous casting mold as the research object,the structure of continuous casting process,the principle of liquid level control,and the requirements of liquid level control system for mould are analyzed.Based on SIEMENS S7 PLC design platform,the hardware and software function of the liquid level control system is designed.Mould liquid level control accuracy is an important process of continuous casting production,which directly affects the quality of the final product.The controlled object of the whole mold liquid level control system is composed of two parts,the hydraulic servo system and the water nozzle executing agency which Mechanism is complex and difficult to model.In the system,there are various kinds of interference which have a complex influence on the liquid level of the mould.,such as the bond,the liquid level of the mould,the vibration of the liquid level,the speed of the fluid,the effect of the drum,and so on.Because of the above reasons,the traditional PID control method can not guarantee the stability of the mold level.Fuzzy control is not required to establish a mathematical model of the controlled object,this paper attempts to introduce the fuzzy control method based on the traditional PID control method.Two algorithms of fuzzy control and PID control are combined to design one controller,which are based on fuzzy reasoning and the PID parameter self tuning controller.At the same time,the liquid level detection is improved,the digital filter is introduced,which can effectively eliminate the interference of high frequency signal and improve the detection precision.Furthermore,the hardware selection,construction and software programming of the fuzzy PID parameter self setting liquid level control system is realized.In the field experiment,the results show that the adaptive fuzzy PID control has very good adaptability.When the liquid level of the mold is not determined by the interference factor,it has good control effect,and can meet the requirements of the process of mold liquid level control.