This paper addresses the control of an experimental PEM fuel cell system. The fuel cell station is composed by an ElectroChem 7-cell stack with Nafion 115 membrane electrodes assemblies (MEAs) and the auxiliary equipment. The control problem is focussed on the air supply in the cathode. The main objectives are to regulate the stack voltage and the cathode oxygen excess ratio. The manipulated variables are the compressor motor voltage and the command current of a proportional valve located at the cathode outlet. A linear and dynamic model at a given operational point is obtained via step tests, which is used in the context of a centralized multivariable Dynamic Matrix Control (DMC).

 The paper deals with the robust control of the dissolved oxygen concentration in the case of wastewater treatment processes. The Gain Scheduling control method has been chosen for the dissolved oxygen concentration control. Firstly the dissolved oxygen control loop was experimental identified in various operating points. The Gain Scheduling strategy was designed so that the behaviour of the closed loop system to be the same around the mentioned operating points. The Gain Scheduling control strategy of the dissolved oxygen concentration was tested by simulation and using an experimentally pilot plant that is also presented in the paper.

 The flood lamination has for principal objective to maintain a downstream flow at a fixed lamination level. For this goal, it is necessary to proceed to the dimensioning of the river system capacity and to make sure of its management by taking into account socio-economic and environmental constraints. The use of flood diversion areas on a river has for main interest to protect inhabited downstream areas. In this paper, a flood lamination strategy aiming at deforming the wave of flood at the entrance of the zone to be protected is presented. A transportation network modeling and a flow optimization method are proposed. The flow optimization method, is based on the modeling of a Min-Cost-Max-flow problem with a linear programming formulation. The optimization algorithm used in this method is the interior-point algorithm which allows a relaxation of the solution of the problem and avoids some non feasibility cases due to the use of constraints based on real data. For a forecast horizon corresponding to the flood episode, the management method of the flood volumes is evaluated on a 2D simulator of a river equipped with a three-flood-diversionarea system. Performances show the effectiveness of the method and its ability to manage flood lamination with efficient water storage.

 The aim of the paper is to present a closed-loop performance analysis of robust tuned two-degree-of-freedom (2DoF) proportional integral (PI) controllers for over damped (first- and second-order) plus dead-time controlled processes. A closed-loop model reference optimization method was follow with non-oscillatory and under damped response targets. The analysis shows that the controlled process model parameters (high time constants ratios or high normalized dead-times) impose a restriction on the robustness obtainable when highly oscillating closed-loop responses targets are specified. The nonoscillatory response targets produce the smoothest controller outputs. The regulatory and servo-control performance (integrated absolute error and settling time) may be improved if lightly under damping responses (0.691 0.780) are allowed but affecting the control effort characteristics (its smoothness and maximum values).

 This paper tackles the problematic of ship stabilization using optimal amounts of resources, in the case of loading and unloading operations on docked vessels. A mathematical model linking the ships positioning and orientation with the forces and moments exerted upon the hull is required in order to develop an optimal control strategy for the ships stabilizing ballast systems. This strategy is designed using graph theory concepts, and it focuses on generating an optimal command sequence in respect to minimum energy consumption taking into account the ballast systems topology.