Designing the NGC system of a small ASV for tracking underwater targets

• A novel ASV/UUV system is described.
• The ASV is able to track autonomously the UUV after deployment.
• A suitable behavioral tracking strategy is defined and implemented.
• Stability of the involved control law is proved.
• Performances are evaluated by simulations.

The paper describes the development of the Navigation, Guidance and Control system of a small, prototypal Autonomous Surface Vehicle (ASV), which is part of an ASV/UUV (Unmanned Underwater Vehicle) robotic system. The main task of the ASV is to serve as supply vessel for the UUV it can carry, deploy and recover and to allow communication with a remote control station. The main problem the NGC system has to handle is that of making the ASV track the UUV and maintain the relative distance within a given bound, using delayed information about the UUV position provided by an acoustic tracking and positioning systems. The specific tracking problem is formulated in a suitable way and a strategy for its solution is proposed and implemented by means of an appropriate control architecture. Stability is discussed using Lyapunov techniques and performances are shown by means of simulations.