变论域模糊PID在微碳汇测量系统中的仿真研究

摘要

在微碳汇研究中,分析植物在不同温度条件下的碳转换能力是必要的.针对微碳汇测量系统中温度变化具有的非线性、时变性、滞后性等问题,提出一种改进型变论域模糊PID控制方法.该方法采用分段函数作为伸缩因子,实现论域的等效伸缩;分段函数伸缩因子在保证控制精度的同时减少运算步骤,从而减小系统的滞后性,提高系统响应的实时性.采用MATLAB/Simulink分别对PID控制器、模糊PID控制器、变论域模糊PID控制器进行建模仿真,仿真结果表明:采用改进变论域模糊PID方法控制系统温度,调节时间短,最大超调量小,跟踪能力好,能为研究植物碳汇能力与温度的关系提供良好基础.%In the study of micro carbon sink,it is necessary to analyze the carbon conversion ability of plant under different temperature.For the problems such as nonlinear,time-varying and hysteresis of temperature in micro carbon sink measurement system,an improved variable universe fuzzy PID control method was proposed.Piecewise function was used as contraction-expansion factor to realize the equivalent contraction and expansion of universe.The contraction-expansion factor ensured control accuracy while reducing the computational steps so as to reduce the lag of the system and improve the real-time performance of system response.The PID controller,fuzzy PID controller,improved variable universe fuzzy PID controller were simulated and analyzed by MATLAB/Simulink.The simulation results showed that with the improved variable universe fuzzy PID temperature control system,the adjust time is short,the maximum overshoot is small and the tracking ability is good,which can provide a good basis for studying the relationship between plant carbon sink capacity and temperature.