How to Choose Suitable Physics-Based Models Without Tuning and System Identification for Model-Predictive Control of Open Water Channels?

Model predictive control (MPC) is used to manage water systems, and its performance depends on the (internal or control-oriented) model it is based on. Several models for the hydraulics of open water systems are presented in literature and used in applications, but their performance has not yet been investigated systematically, and no guideline exists on which model to select for a certain channel. The aim of this research is to present a guideline for model choice based on the geometry of the channel and the flow conditions. The guideline is developed by first categorizing the channels into four types, followed by performing time-domain, frequency domain, and closed-loop tests for all models and channel types. The evaluation of the tests shows that for short and wave-dominated channels, the Muskingum, Integrator Delay, and Integrator Delay Zero models perform the best, while for longer channels the linear inertial model is the most suitable. Finally, a decision-tree is presented how to choose the model. Lastly, a decision-tree is introduced to aid in the selection of the most appropriate model.