Simulation of an AUV (autonomous underwater vehicle) dragging a GPS buoyage system

In the past, an autonomous underwater vehicle (AUV) is commonly navigated by a GPS antenna, and the AUV must periodically sink and emerge. We now present a new method for navigation of an AUV by dragging a GPS buoyage. In the full paper, we explain our method in detail. In this abstract, we just add some pertinent remarks to listing the two topics of explanation. The first topic is the three-dimensional motion model of the dragging cable. In the first topic, we analyze the forces of the cable, and based on the d'Alembert theory, we build the three-dimensional motion equations of the cable. The second topic is the boundary conditions of the cable. In the second topic, we explain in some detail that the boundary conditions are different from the initial conditions of the commonly dragged system. We solve the motion equations through a shooting method. The simulation results, summarized in Figs. 3 and 4, and Table 1 in the full paper, show preliminarily that the navigation method by dragging a GPS buoyage is viable because the shape of the cable can be determined by solving the motion model of the cable; the shape of the cable is an approximate beeline, and the cable tensile force from the GPS buoyage to the AUV is increscent. The simulation results also show that the force exerted by the cable on the AUV increases with the AUV's velocity, and it is advantageous for an AUV to move at a low velocity when it drags a GPS buoyage.