A gain scheduling approach to improve pressure control in water distribution networks

Real time pressure control is a common technique adopted to face the problem of leakage reduction in water distribution networks. Recently, in the context of Water 4.0, the spread of wired water distribution networks has opened new possibilities in terms of sensing and communication, resulting in the possibility of adopting higher sampling rates and consequently higher closed-loop bandwidths for the control system. While this could be exploited to improve the performance, it has also drawn the attention of the fundamental question of closed-loop stability, which was seldom considered in a systematic way, especially in the hydraulic community. This works aims to combine some recent results in term of design of frequency domain controllers with a gain scheduling approach, to account and compensate for the main nonlinearities affecting the system under control, and to preserve stability and robustness of the closed-loop in a wide operating region. The approach is validated by means of simulated experiments performed on a detailed dynamic model of the water distribution network. In addition, the gain scheduling approach can improve the overall performance of the control scheme and allows avoiding heavy retuning of the regulator when applied to the nonlinear system.