Rui Gomes

Neptus - a framework to support multiple vehicle operation

This paper describes the development of a C3I (communications, command, control and intelligence/information) infrastructure, taking place at the Underwater Systems and Technology Laboratory (LSTS) of FEUP. This infrastructure, the Neptus framework, goal is to support the coordinated operation of heterogeneous teams, which include autonomous and remotely operated underwater, surface, land, and air vehicles and people. People perform a fundamental role, not only in the case of remotely operated vehicles, but also with autonomous vehicles where mix-initiative operation is a requirement. The operational scenarios for these teams are mainly environmental monitoring missions but could also include environmental disaster scenarios, rescue missions, etc. The Neptus distributed architecture is service oriented, which enables high degrees of interoperability between applications, of scalability (number of nodes), and of reconfiguration (number and type of nodes).

A new ROV design: issues on low drag and mechanical symmetry

This paper reports the design of a new remotely operated underwater vehicle (ROV), which has been developed at the Underwater Systems and Technology Laboratory (USTL) - University of Porto. This design is contextualized on the KOS project (Kits for underwater operations). The main issues addressed here concern directional drag minimization, symmetry, optimized thruster positioning, stability and layout of ROV components. This design is aimed at optimizing ROV performance for a set of different operational scenarios. This is achieved through modular configurations which are optimized for each different scenario.

An impulsive framework for the control of hybrid systems

An impulsive control formulation suitable for analyzing hybrid systems is presented. Besides a continuous evolution, the trajectory of an impulsive control system may also exhibit jumps. The jump trajectory is well characterized in this impulsive framework. These jumps can be interpreted as the discrete evolution of an hybrid system. Several examples of hybrid systems modeled in the impulsive framework are given. An impulsive formulation of a formation control problem, regarded as an hybrid system is detailed. Finally, an overview of important classes of control results available for impulsive control systems, notably, stability and optimality, attest the importance of this paradigm for the control of hybrid systems. These results are essential to investigate the properties of model predictive control schemes for hybrid systems.

A Model Predictive Control Approach to AUVs Motion Coordination

The problem of coordinating the motion of autonomous underwater vehicles under constrained acoustic communications is formulated and investigated in the context of the model predictive control (MPC) framework. The impact of acoustic communications and perturbations on the motion performance and robustness is discussed. A reach set formulation of the MPC scheme is outlined.

A Robust Reach Set MPC Scheme for Control of AUVs

A Robust Model Predictive Control (MPC) scheme for the control of formations of Autonomous Underwater Vehicles (AUVs) is presented and discussed. This application domain is extremely relevant and exhibits very difficult control challenges: (i) slow, low data-rate acoustic communications, (ii) significant perturbations inherent to the hydrodynamic environment, (iii) unexpected emergence of obstacles, and (iv) severe onboard computation constraints. While the later aspect is discussed by the Reach Set MPC scheme implementation which maximizes the a priori off-line computation as enabled by taking into account, as much as possible, invariant data, the other challenges are addressed by increasing the robustness of the proposed basic MPC scheme by considering a number of intermediate steps which, in spite of the increase of the on-line computational burden, this remains strongly lower than the one associated with typical standard MPC schemes.