Necessity of Hydrostatic Stability in Autonomous Underwater Vehicles on Intervention Missions
Tobias Rossol, Christian Ernst Siegfried Koch, Ralf Bachmayer, Frank Kirchner
In OCEANS 22 Hampton Roads, (OCEANS-2022), 17.10.-20.10.2022, Hampton Roads, VA, IEEE, pages 1-10, Oct/2022. MTS / IEEE OES.
Most underwater vehicles are hydrostatically stable, i.e., their center of gravity is placed below their center of buoyancy, providing passive stability in pitch and roll. While this design is favorable for fixed attitude missions, it is a hindrance for tasks requiring flexible orientation control. This work examines the influence of hydrostatics on attitude control of a fully actuated intervention type Autonomous Underwater Vehicle (AUV). We conducted a simulation study varying influencing factors, such as hydrostatic stability, thruster dynamics, disturbance, and controller choice. We found that the impact of hydrostatic stability on control performance and energy consumption is drastically reduced, if thrusters with sufficiently high dynamic range are used. Our results support the concept of intervention AUVs, which are highly agile through marginally stable design.
autonomous underwater vehicle, hydrostatic stability, attitude control, thruster model, hydrobatics