In this paper, we investigate the leader–followers Time-Varying Formation Tracking (TVFT) problem of a networked Multi-Agent Systems (MASs) based output feedback. The agents’ behavior is featured by linear dynamics. The interaction topology among the agents is switching over time, directed and only assumed to contain a directed spanning tree. This latter is rooted by a leader-agent whose control input is unknown and bounded. A novel fully distributed TVFT controller is proposed that exhibits a reduced network information exchange property among the agents, thus less communicating-resources are utilized. The proposed controlled design is based on an adaptive observer and disturbance rejection technique, where the unknown leader-input is viewed as an external disturbance. The key feature lies in introducing a local observer in each agent-controller design to observe all the relative neighboring output-measurements and the relative neighboring distributed observer-outputs, all gathered in one signal that we denote the agent’s network information signal. The Lyapunov theory is used to prove that the closed-loop MASs tracking error is stable. An analysis of the effect of the interaction topology structure on the tracking-error convergence rate is further provided, showing the validity of the proposed formation control for switching interaction topologies. Finally, to verify the effectiveness of the obtained results, the proposed controller is extended to a cooperative guidance of a networked quadrotors to track and entrap an uncooperative aerial target that plays the role of a passive leader.

Over the last decade, the focus on the use of computer tools to assess flows around submarines and guide their design has been considerably developed. In particular, with the emergence of parallel computational capabilities, RANS simulations of viscous flows have seen a greater role in predicting these flow fields. The shift to a much more CFD-based design and analysis approach leads to the ability to achieve better designs in the shortest time. This makes it possible to classify several ranges of designs as well as to provide an entire image of the flow field, which can lead to a better understanding of the flow field’s physics. The aim of this study consists of a 3D numerical simulation of the turbulent flow around a submarine without and with appendages to quantify the effect of each appendage on total drag and to study the interaction between the submarine hull and its appendages. The hydrodynamic turbulent flow behavior around the well-defined shape is described using the ANSYS CFX code to resolve the RANS governing equations. Good agreement is obtained from the validation of the numerical results confirming the efficiency of the method in terms of computational time and robustness. The numerical approach is adopted to predict the flow field and forces and moments acting on the underwater vehicle for different maneuvering cases and simulation results have been presented.