Consistency Techniques for Simulation of Wastewater Treatment Processes with Uncertainties

In this paper, interval simulation methods are presented to determine guaranteed enclosures of state variables of an activated sludge process in biological wastewater treatment. This process is characterized by nonlinearities and uncertain but bounded parameters. In uncertain systems an axis-parallel interval box is mapped to a complexly shaped region in the state space that represents sets of possible combinations of state variables. The approximation of this complex region by a single interval box causes accumulation of overestimation over simulation time. The algorithm presented in this paper minimizes this so called wrapping effect by applying consistency techniques, to avoid safety-critical states. Copyright ©2005 IFAC