Dynamic Modeling and Control of Autonomous Underwater Vehicles with Multi-Domain Communication Systems

This thesis presents a comprehensive study on the dynamic modeling and autonomous control of an Autonomous Underwater Vehicle (AUV), with the REMUS platform as a reference model. The work begins with the formulation of the vehicle’s equations of motion based on Newton-Euler principles, which are then structured following the nonlinear marine vehicle model introduced by Thor I. Fossen. This framework captures the interaction of forces and moments acting on the vehicle, considering both inertial (NED) and body-fixed (BODY) reference frames. Hydrodynamic coefficients, essential for accurate modeling, were sourced from literature where they are derived through experimental testing, towing tank data, and CFD simulations. The validated model is used to design a robust autopilot system based on Sliding Mode Control (SMC), chosen for its effectiveness in nonlinear environments, low sensitivity to parameter variations, and resistance to disturbances such as underwater currents. The control action is applied to the vehicle’s control surfaces, regulating pitch and yaw to achieve target-point convergence. Guidance is performed through a Line-of-Sight (LOS) strategy, which computes a desired direction in 3D space by minimizing lateral deviation—both horizontal and vertical—from the intended path. The control architecture supports multipoint tracking, enabling flexible navigation across predefined trajectories. Controller tuning was carried out to ensure smooth convergence and to reduce chattering effects commonly associated with SMC. The final phase of the project integrates a multi-domain communication scenario, simulating the exchange of target information between the AUV and an aerial surveillance vehicle modeled in a parallel study. This data-driven collaboration allows dynamic trajectory recalibration, improving mission adaptability and laying the foundation for future multi-agent and multi-domain autonomous systems.