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Concerns an irrigation canal with hydromechanic AMIL gates. This gate is used for proportional control of local upstream water level. The gates are associated with upstream water distribution. The stability was studied on a coupled canal pool-AMIL gate subsystem, then on two coupled subsystems. A type turnout perturbation is supposed to be in the upstream side close to the gate. The dimensionless St Venant equations are linearized around a normal steady flow. By Laplace transform, a feasible system is established. By integration, the distributed parameter system was obtained. It represents the canal pool dynamics. The gate dynamics is supposed as succession of steady states. The transcendent transfer function is established by coupling the pool dynamics representation and the linearized discharge equation of the gate. The resulting stability condition depends on dimensionless numbers and the linearization parameters of the discharge equation. In the first case, a sufficient and necessary condition for unconditional stability is found. In the second case, a sufficient condition is found. We propose an easy-use stability sufficient condition for coupled subsystems. A general method was used in order to study the wave motion stability for simple and coupled subsystems. This method can be directly applied when studying the stability problems of all canal pool-motorized hydraulic structure (controller) system. Obtained conditions can be used like design norms of irrigation canals.

In this paper, H ∞ approach is applied in order to design robust controllers for irrigation canals. From an automatic control point of view, an irrigation canal is a strongly coupled multi-variable system. More precisely, it is a cascade of sub-systems (pools) where the control input of each sub-system perturbs the previous sub-system. Control laws are usually obtained by designing monovariable controllers for each subsystem with some ad hoc improvements in order to take into account coupling effects. In this paper, we propose to formulate the design objectives as a weighted H ∞ optimization problem. To this purpose, we propose a simple guideline for writing a weighted H ∞ optimization problem taking into account design objectives. The monovariable case is first considered, that is, the control of one sub-system. The obtained H ∞ controller is then compared to a classical PID-like controller. Second, the same approach is applied to the multivariable case. The obtained controller, which is indeed multivariable, is then analyzed and tested in the non-linear case.

Open-canal-hydraulic-related difficulties contributed a lot to evolving numerous automatic control methods. Most of them can be described as strategies of flow control whose objectives are to overcome long time delays and to satisfy unforeseen users demands and needs. Our paper intends to investigate the applicability of the Generalized Predictive Control technique to the first two reaches of the canal 2 proposed by the ASCE Task Committee on Canal Automation Algorithms. The control strategy is based on the control of the downstream water level of each reach by controlling both upstream discharges and thus the cross-gate opening.