Control Method for On‐Demand Operation of Open‐Channel Flow

Abstract

The basic unit in a free‐surface controlled water distribution network could be composed by a single reach with upstream and downstream gates. Different methods have been proposed in the literature to control water level, volume, or discharge in the reach. All of them use the same basic intrinsic assumption about the controlled reach: Every magnitude of intake and offtake of the reach has to be known. Consequently, unknown disturbances cannot be compensated. This paper proposes a new method with the purpose of manipulating the upstream gate to make the downstream discharge follow the demanded set point. It is formulated by means of a discrete‐time algorithm that computes, at each sampling instant, the control upstream gate opening using the measurement of the water levels at both sides of the gates as feedback information. The method allows the presence of unknown disturbances in the reach in the form of intake or offtake discharges, and it is able to drive the downstream discharge to the demanded set point and maintain it in spite of them.