Unmanned Systems Technology 036

Diversity factors 46 A s the biodiversity of the world’s oceans is manifested in the incredible range of shapes, sizes and behaviours of their denizens that allow them to find and exploit a particular environmental niche, so this is reflected in the evolution of UUVs. While 10 years ago there were just a few different UUV designs, most of them being shaped as a torpedo or a rounded buoy, these days they come in hundreds of different forms. They are also coming in smaller and larger shapes than ever, and feature increasingly unusual arrangements of thrusters, payloads and other components to better handle the growing range of mission sets that operators in the sector are giving them. Seabed operations Autonomous Robotics’ Flying Node UUVs represent one of the best visual examples of underwater robots evolving in shape and capability to specialise in their given field. They are being developed for particular use in node seismic surveys, to produce sub-bottom geophysical maps of regions of the seabed where oil & gas companies are looking for suitable extraction sites. As discussed in UST 32 (June/July 2020) in the context of aiding USVs, node seismic surveys are gaining popularity across the industry, but are cumbersome owing to the need for thousands of carefully placed geophones across the seabed. “The big difference with our UUVs is that they can land on the seabed,” explains Arran Holloway, engineering director at Autonomous Robotics. “They ‘fly’ down and sit on their portion of the seabed for months at a time, recording data using geophone equipment integrated in their hulls. “ROVs used to be the usual tool for placing geophones on the seabed one at a time, but that takes a very long time, while towed-cable seismic surveys are quicker but much less accurate in finding faults and other indicators of where not to drill for hydrocarbons. The autonomy, accuracy and low cost of our system will improve considerably over the drawbacks of previous methods.” The unusual capability of the Flying Nodes to sit on the seabed and then leave without being entangled in vegetation or stuck in soil comes from a number of key design points. For UUV designers continue to take inspiration from the aquatic realm to provide vehicle shapes and sizes for a growing variety of missions. Rory Jackson reports February/March 2021 | Unmanned Systems Technology The Flying Nodes can vary their buoyancy in order to sit firmly on the seabed, potentially to act as seismic sensors and transponders for oil & gas geological surveys (Courtesy of Autonomous Robotics)