Modeling and simulation of a spherical vehicle for underwater surveillance

Open-source Simulation of Underwater Gliders

“…Moreover, added mass effects arise due to the exchange of inertia between a vehicle in motion and the surrounding fluid [9]. As the added mass coefficients depend on the geometry of the vehicle, in Section IV-C a procedure is illustrated to compute these parameters based on the assumption that the glider's hull can be approximated as a prolate spheroid.…”

“…When modelling AUGs, the buoyancy force can be split in two contributions, one due to the constant volume of the vehicle (B h ), acting on the hull volume centroid, and a second one generated by the VBD, acting on the centroid of the VBD (B V ). The notation reported in [9], can be extended as:…”

“…No library is specifically available for underwater vehicles but the Modelica language has already been used to simulate multibody underwater vehicles in [9] and space vehicles in [14].…”

“…The simulator architecture proposed in this work follows the structure illustrated in [9]: the vehicle is designed as a multibody system by linking components from the Mechanics-MultiBody library through prismatic and 3D revolute joints. As reported in Figure 2, the system comprises 6 main rigid bodies representing the hull, the sliding, the rolling, the offset, the ballast and the VBD masses.…”

“…The simulator is designed starting from the multibody mechanical library of OpenModelica and adapting some components to the underwater application, extending the work previously proposed in [9]. The architecture is composed of several masses representing the hull, the movable masses, the VBD, and the steering surfaces, and by applying the hydrostatic and hydrodynamic forces at the interfaces.…”