INTERVAL ESTIMATOR FOR CHLORINE MONITORING IN DRINKING WATER DISTRIBUTION SYSTEMS UNDER UNCERTAIN SYSTEM DYNAMICS, INPUTS AND STATE MEASUREMENT ERRORS

The design of interval observer for estimation of unmeasured state variables for application to drinking water distribution systems is described in this paper. In particular, it considers the design of such observer for estimation of water quality described by free chlorine concentration. An interval observer is derived to produce robust interval bounds on the estimated water quality state variables. The stability and robustness the interval observer are investigated under uncertainty in the system dynamics, inputs, and initial conditions and under the state measurement errors. The observer is applied to an example water network and its performance is validated by simulation.