Control design for an irrigation channel from physical data

In this paper a tool for initial design of decentralized controllers for an irrigation channel is developed, and field tests are carried out which demonstrate that it delivers controllers with good performance. A physical model of the channel is obtained using the Saint-Venant equations, and a data set is generated by simulating this model. A first order nonlinear model useful for control design is then estimated from the simulated data using system identification techniques, and a controller is designed based on the estimated model and given design specifications. The decentralized controller is a PI controller augmented with a first order low pass filter. The developed routine for controller design is based on frequency response methods, and configurations with and without feedforward from the downstream gate are considered. The designed controllers showed good performance in field experiments; the water levels recovered quickly from disturbances with small deviations from setpoints. (C) 2008 Elsevier Ltd. All rights reserved.