污水处理过程多变量控制方法研究

A research of multivariable control method in sewage treatment process

针对在污水处理过程中存在的多变量相互影响,单变量控制显然不能满足其要求的情况下,本文提出了2种分级多变量模糊控制方法,分别为基于模糊PID-Smith和模糊理论的2级控制和基于双模糊PID-Smith理论的2级控制。这2种控制方法均采用1个双输入、单输出的控制器,它在结构上分为2级,其中基于模糊PID-Smith和模糊理论的2级控制器的第1级结构为模糊PID-Smith控制,第2级结构为模糊控制;而基于双模糊PID-Smith理论的2级控制的2级结构均为模糊PID-Smith控制。这2种控制器的设计方法不但解决了多变量模糊控制规则难以制定的问题,又充分的考虑了其他因素对控制量DO的影响,从而实现了污水处理过程中的多变量模糊控制。本文利用MATLAB软件实现了这2种控制方法的设计与仿真,并和单变量模糊控制进行了比较,总结了多变量模糊控制的特点和优势,指明了把多变量模糊控制应用于污水处理系统是切实可行的。

Because the presence of multivariate interaction in the sewage treatment process and univariate control obviously does not meet its requirements, this paper puts forword two types of multivariate fuzzy control methods： one is two-levels control based on fuzzy PID-Smith and fuzzy theory, the other is two-levels control based on the double fuzzy PID-Smith theory. Both control methods use a dual-input, single-output controller, it is divided into two levels in the structure： two-levels controller based on fuzzy PID-Smith and fuzzy theory is that controller where the first-level structure is fuzzy PID-Smith Control, second-stage structure is fuzzy control, two-levels controller based on the double fuzzy PID-Smith theory is that controller where the two-levels structure both are fuzzy PID-Smith Control. These two kinds of controller design method not only solve the problem that the multivariable fuzzy control rules are difficult to formulate, but also fully consider the influence of other factors on the control volume DO. This paper realizes the design and simulation of the two kinds of control method by using MATLAB software. Compared with univariate fuzzy control, it summarizes the characteristics and advantages of the multivariable fuzzy control and indicates that it is feasible to apply the multivariable fuzzy control to the wastewater treatment system.