Application Research Of Fuzzy-PID Self-tuning Controller For Microwave-Vacuum Wood Drying Process

Wood drying is an important measure to economize on wood and increase its utilization. Microwave-Vacuum drying(MVD) is low-temperature drying technologies with fast drying rate and environmental advantages, which combines with two technical advantages of microwave heating and vacuum drying. It not only can overcome that individual microwave drying process is vulnerable within the crack and internal burnt defects because of high temperature, but also resolves the heat transfer problems easily making by air media scarcity in separate vacuum drying process, meamwhile, the drying costs is reduced and the drying time is decreased substantially. Consequently, it's a great development and application of technology that the microwave-vacuum drying technology applied to wood drying.Microwave-vacuum drying of wood process has some characteristics such as nonlinear, hysteresis quality, uncertainties and so on, so as to design effective automation control system becomes particularly important. A fuzzy self-tuning PID controller is designed on the basis of theoretical analysis of wood drying control procedures, combining with fuzzy control's intelligence and conventional PID control reliability, fuzzy inference method is used to implement a PID online setting. Based on MATLAB/Simulink tools for simulation, by simulation, analysis and comparison of conventional PID and fuzzy self-tuning PID control of drying kiln, it's showed that the step response curve controlled by fuzzy self-tuning PID has risen fast, steady performance, short transition process time, small overshoot and other advantages like this, control features meet the system requirements. This will increase the wood drying process control level, guarantee the wood drying quality effectively, decrease energy consumption and reduce costs, which have important meaningful for theoretical research and practical application.With the characteristic of large algorithm operational capacity for fuzzy self-tunig PID, at the same time the need to ensure that real-time features, hardware implementation approach is explored, TMS320LF2407A DSPs from TI company control series is selected as the processor. In order to reduce difficulty and workload to write DSP code for the developers, improve overall DSP system performance and feasibility, the MATLAB/Simulink platform DSP code development and design process is given.This article propose the microwave-vacuum drying of wood control system based on fuzzy self-tuing PID, increased the control accuracy and stability, It is an beneficial attempt taking advantage of advanced process control algorithms to solve the actual problem. Meanwhile, system architecture design is reasonable, practical and satisfied for the automation control requirements microwave-vacuum drying of wood.