UNIVPM BRAVe: A hybrid propulsion underwater research vehicle

In the last decade, the underwater activities performed by archaeologists and biologists have benefited from scientific research on the guidance, control, and sensory systems of unmanned vehicles. In fact, because underwater sites of interest are often difficult for divers to access, the use of unmanned vehicle technology to conduct surveys could be quite advantageous. In this paper, a novel and partially-biomimetic underwater robot, referred to as BRAVe (Biomimetic Research Autonomous Vehicle), is presented. For documentation purposes, it is equipped with a hybrid propulsion system, which consists of two different types of thrusters. The thrusters are designed to compensate for their reciprocal flaws in order to achieve a more efficient overall system. Specifically, the biomimetic thruster is employed for its superior energetic efficiency, and the horizontal propellers are exploited for accurate maneuvering. While the documentation and 3D reconstruction of the underwater seabed is a consolidated aspect for the authors, the hybrid propulsion system represents the main innovation of the present work. The increase in efficiency achieved by this propulsion system allows the vehicle to perform a thorough and precise documentation of underwater remains within short distances, while exploiting the maximum possible autonomy. This article discusses the details of the development of all the vehicle compartments and their associated characteristics, focusing on the significance of this technology. In addition, the results of 3D reconstructions extrapolated from images taken during real field missions are presented.