Control design for an irrigation channel from physical data

In this paper a tool for initial control designs for an irrigation channel is developed. The idea is that a physical model of the channel is obtained using the St. Venant equations, and a data set is generated by simulating this model. A first order nonlinear model is then estimated from the simulated data using system identification techniques, and a controller is designed based on the estimated model and the given design specifications. The controller is a PI controller augmented with a first order low pass filter in order not to amplify waves present in the channel. The developed routine for controller design is based on frequency response design, and configurations with and without feedforward from downstream gate are considered. The designed controllers have shown good performance, and they are able to track setpoint changes and the water levels recover from disturbances with small deviations from setpoints and without excessive oscillations.