CONSTRUCTION OF AN ONLINE FUZZY CONTROLLER FOR THE DYNAMIC ACTIVATED-SLUDGE PROCESS

This paper presents and discusses an alternative approach, called fuzz y control theory, which can forecast and control complex, uncertain an d/or highly-non-linear systems properly. Building the set of control r ules is a very difficult task in fuzzy control and they are generated through on-line operation data in this study, not through experts' kno wledge and/or operators' opinions, which is different from conventiona l applications. The fuzzy control theory can be conveniently used as a n aid for automatic control, especially for complex and highly-non-lin ear systems. The steps using the fuzzy control technique are issued, c ompared and discussed in this paper and are demonstrated by a case stu dy of a dynamic activated sludge process which is much more complex th an other wastewater treatment systems. The effects of forecast and con trol of the fuzzy controller established from the derived fuzzy model are shown by computer simulation and verified by experiments. The resu lts indicate that the forecast and control utilities of the fuzzy cont rollers are good and very helpful to the understanding of complex syst ems.