一种改进IMC-PID在发酵温控系统中的应用

Application of an improved IMC-PID in fermentation temperature control

发酵过程温度控制过程是典型的大滞后、强时变、非线性系统,传统控制方法难以获得满意的动、静态控制效果。针对这一问题,提出了一种改进的IMC-PID发酵过程温度控制方法。在传统IMC-PID方法的基础上,首先,依据系统的输入与输出信号确定误差e(t)和误差变化率ec(t),其次,利用专家经验获取系统的模糊逻辑规则,最后,采用模糊逻辑算法对IMCPID的比例加权参数进行在线实时修正,实现发酵过程的温度控制。仿真结果表明,所提方法能够对发酵过程温度进行有效控制,与传统IMC-PID控制相比,系统的抗干扰性和跟踪特性得到显著改善。

In temperature control of biological fermentation,time delay,non-linearity and time-varying characteristics often exist, taking some trouble to obtain satisfactory dynamic and static control performance. To solve this problem,this paper uses an improved IMC-PID control method based on the traditional IMC-PID method. First,based on the input and output signals of the system it determines the error and rate of error; secondly,it gets fuzzy logic rules by expert experience,and finally the set-point weight of the proportional part carried on the improved IMC-PID controller is modified online by fuzzy logic algorithm to achieve the fermentation process temperature control. The simulation results show that the proposed method can control the temperature of the fermentation process effectively,compared with the conventional IMC-PID control,the anti-jamming and tracking characteristics of the system have been significantly improved.