Comparative performance investigations of the intervention-class underwater vehicle with different possible thruster configurations using eight identical thrusters

Abstract

Different thruster configurations (TCs) or arrangements are used in underwater vehicles (UVs) to perform various deep-sea intervention operations. The location and arrangement of thrusters and the number of thrusters can vary the overall vehicle’s performance. However, a comparison study of the effect of these different TCs or performances is yet to be available in the literature. This study will provide a base for the vehicle design and choice of thruster along with their arrangements. Therefore, in this paper, computer-based numerical simulations are conducted with these TCs using eight identical thrusters on a common vehicle platform to analyze their relative performances under different operating conditions. The performance parameters studied in this paper are position error, orientation error, and energy consumed. Initially, the maximum allocated force and moments in the vehicle’s fixed frame are found by giving a constant input force to the thrusters. Then the TCs are simulated with closed-loop trajectory tracking tasks of following simple to complex profiles to identify the configurations that better perform tracking the given desired trajectories. Several computer-based simulations are conducted in the presence of underwater currents. Vectored horizontal TC (inclined to surge and sway axis) and 3D vectored TCs consume more energy than horizontal and vertical TCs. Energy consumption in horizontal and vertical TC is found to be 30 % and 23 % lesser than 3D vectored TC in the absence and presence of underwater currents, respectively, for the same trajectory tracking simulation.