Research on double closed-loop tea fixation control system based on fuzzy PID

SHEN Bin， ZHANG Xian， ZHAO Zhang-feng， ZHONG Jiang
（Key Laboratory of E&M， Ministry of Education & Zhejiang Province， Zhejiang University of
Technology， Hangzhou 310014， China）

Abstract： In order to improve the effect of fixation，fuzzy PID technology was investigated. The structure of the fixation system and the operating principle and the methods of fixation were analyzed. The method was proposed that taking the moisture content of water-removing tea as the control index，together with changing the temperature of the cylinder wall to dominate the moisture content. A double closed-loop control system of moisture content and temperature based on fuzzy PID control algorithm was designed. Finally，the system was simulated by Matlab，and a comparative experiment about the effect of fixing was conducted. The results indicate that by applying fuzzy PID control algorithm to fixation system instead of using conventional PID control algorithm，the step response of the system costs less accommodation time and leads to smaller overshoot. It can well suit to the circumstances that tea moisture is changing based on the index of the moisture content of water-removing tea.
Key words： fixation machine； fuzzy PID； double closed-loop； moisture content