Error feedforward control for irrigation channels

In order to reduce water wastage in irrigation channels, implementing an appropriate control strategy is crucial. Two commonly used strategies are immediate upstream and distant downstream control. In this paper, we focus on distant downstream control since it results in less water wastage in demand-driven systems. It has been shown in the literature that a feedback with feedforward (FBFF) configuration yields better performance than feedback alone. In the FBFF configuration, the control action of a gate is fed forward to its upstream gate. We propose a variation of FBFF configuration where, instead of control actions, the water level deviations in a pool are fed forward to its upstream pool and we show the two configurations are equivalent under certain conditions. We analyse the error propagation for both configurations and compare them in simulations of 7-pool systems, considering both identical and non-identical pools. A system-model mismatch is also considered in the simulations.