Simulation Of Fuzzy PID In Wood Plastic Compound Material Temperature Control

Wood plastic compound material just has the advantages from both wood and plastic, so it is the emphasis that the companies study and develop more and more, and becomes green compound material with environmental protection, which has high performance, high value-added. So how to reduce energy consumption, increase the quantity and quality of the compound material by automatic control system is problem this field needs to solve, in the extrusion process of wood plastic compound plastic. According to technology demand, it is extremely important for productivity and quality to control material barrel of extruder and temperature of machine head, reduce its fluctuations.The paper took extrusion temperature of wood plastic compound plastic as object to study, firstly analyzes technology demand and principle of extrusion temperature of wood plastic compound material, according to it, control idea and program of extruder of wood plastic compound material are proposed. Based on the characteristics of PID, parameter setting algorithm and fuzzy control, a compound control scheme—fuzzy PID control method is proposed, and then the comparison of PID control and fuzzy is made in simulation.Main content the paper studied is as follows:1. the paper studied control method that extrusion temperature of wood plastic compound material uses further, preferred control method is PID control. The important of PID control is to adjust parameter. The paper applied Ziegler-Nichols, Chien-Hrones and human setting to set its parameter. Because of delay, when the system is controlled by PID, control method of PID combining Smith predictor is considered.2. the second method is fuzzy control, the mechanism of fuzzy control is studied, the mechanism of fuzzy control is studied, and the fuzzy controller's structure of extruder is determined. Rules table of fuzzy control is made by analyzing temperature characteristic of extruder of wood plastic compound material.3. for characteristic and difficulty of extrusion temperature controlled, fuzzy PID control method is proposed, the method applies to extrusion temperature system of wood plastic compound material, and is analyzed in detail.4. software of MATLAB and Simulink is introduced. The simplified model of extruder is taken as controlled object and simulation experiments are made for fuzzy PID control in MATLAB, which is also compared with PID control, fuzzy control and PID including Smith. It is shows that fuzzy PID control method has good dynamic and static performance, strong robustness and disturbance-rejection ability. In addition, it is simple for system designing and the research laid the groundwork for the application of this arithmetic in industrial control.