Abstract
This paper deals with the design of a robust multimodel controller using QFT
(Quantitative Feedback Theory) techniques. The process considered in the paper is a wastewater
treatment one and the aim of the control is the obtaining of an effluent having the substrate
concentration within the standard limits established by law (under 20 mg/l). The process has been
linearized in three steady state functioning points, corresponding to the three main functioning
regimes: rain/flood, normal, and drought. For each regime a QFT controller has been designed.
Finally a general controller was built through the fuzzy aggregation of the three QFT controllers
mentioned above.
