Tracking control for a formation of Autonomous Underwater vehicles

Abstract

Autonomous Underwater Vehicles (AUVs) are being implemented for a multitude of military and commercial applications, as well as scientific research and surveying. Because of the environment that these vehicles are tasked to perform duties in, there is a need for guidance and control schemes that are precise, yet robust. There are still major research efforts underway in the areas of system identification, modeling, control, and optimization to enhance the autonomy of these vehicles. This will allow for more advanced control schemes while maintaining the robustness that is required to operate in a diverse and hazardous environment such as the ocean. Previous control algorithms for commercially available AUVs have been generally restricted to tracking straight-line trajectories between predetermined waypoints. These vehicles will typically employ an additional control technique that allows for obstacle determination and avoidance. Again, this is generally limited to a simple line of sight detection and preprogrammed avoidance maneuver. An even less abundant and mature group of control schemes is available for a cooperative technique by a group of AUVs to accomplish a common goal. This thesis addresses the development of a robust suboptimal tracking control algorithm that will efficiently and effectively track an identifiable target while maintaining a formation with cooperating vehicles. This work will examine the possibility of utilizing a common LTI control scheme for maneuvering the actual nonlinear vehicle model. It will also investigate a simple heuristic approach to determining how to track a given target, as well as in what formation to maintain the group structure.