Adaptive periodic control for chlorine residual maintenance in drinking water distribution networks

Increasingly stringent requirements on the levels of chlorine residual and disinfectant by-products in drinking water distribution networks have created a need for feedback control approaches. The feedback water quality control problem is formulated in an adaptive control framework with special consideration on the periodic variation of parameter uncertainty due to varying consumer demands. The approach is based on approximating the input/output dynamic behavior of chlorine concentration as a periodic time-varying, discrete-time linear model with uncertain or unknown coefficients. The periodic parametric uncertainty is represented by a Fourier series with on-line parameter estimation of the unknown coefficients. Simulation examples are used to illustrate the performance of the algorithm in a real water distribution network