Dynamics modeling of a semi-submersible autonomous underwater vehicle with a towfish towed by a cable

TLDR

The study develops a dynamics model for a semi‑submersible autonomous underwater vehicle system comprising a towing vessel, tow cable, and towfish. The model represents the towfish with a 6‑DOF equation of motion, the cable with an absolute nodal coordinate formulation, and incorporates added‑mass and drag forces to capture hydrodynamic effects. Numerical simulations confirm the model’s physical plausibility.

Abstract

In this paper, we employ a dynamics modeling method for investigating a multi-body dynamics system of semi-submersible autonomous underwater vehicles consisting of a towing vehicle operated near the water surface, a tow cable, and a towfish. The towfish, which is towed by a marine cable for the purposes of exploration or mine hunting, is modeled with a Six-Degree-of-Freedom (6-DOF) equation of motion that reflects its hydrodynamics characteristics. The towing cable, which can experience large displacements and deformations, is modeled using an absolute nodal coordinate formulation. To reflect the hydrodynamic characteristics of the cable during motion, the hydrodynamic force due to added mass and the drag force are imposed. To verify the completeness of the modeling, a few simple numerical simulations were conducted, and the results confirm the physical plausibility of the model.