基于Fuzzy-PID的MOCVD温度控制方法

Research on MOCVD temperature control based on Fuzzy-PID

针对MOCVD系统反应室温度的特性和对温度控制的要求,提出了一种基于Fuzzy-PID的温度控制方案,即利用模糊控制求得归一化的PID参数变化系数,从而实现PID参数的在线自调整.与Smith预估控制相比,Fuzzy-PID具有更好的控制效果,较好地解决了系统中存在的“非线性”、“大滞后”、“物理模型不精确”等问题,满足MOCVD控制系统温度控制要求.

According to the temperature characteristics of the reactor and the requirements for temperature control in the MOCVD system, a kind of Fuzzy-PID temperature controller is proposed. Fuzzy-PID can rea＇ize the PID parameters on-line self-regulation, normalizing varying PID parameter coefficients into the range between 0 and I by using fuzzy control. In addition, the corresponding simulation is given. The results indicate that the Fuzzy-PID controller has better control performance （ such as non-hnearity, hysteresis and unprecision physical model） than the Smith controller, and can meet the design requirements for the MOCVD temperature controller.