A JIP to design a new subsea docking system would enable faster data transfer and AUV charging
Despite improvements in the ability of sensors and vehicles to gather data, successfully transmitting it is still a difficult task. The large amounts of information gathered by autonomous underwater vehicles (AUVs) require a sizable bandwidth and power reserve for transfer, and even with a strong wireless or 4G signal, the optimal method is physically to connect to a cabled network (or to wait until the craft is picked up by a human crew and transferred manually).
Given that most subsea infrastructure already has cabled connections to shore in place, as well as access to electric power, this presents an optimum solution and would allow AUVs an opportunity both to transfer data and recharge batteries. Yet existing subsea connection systems typically employ conductive pins; these require tight mating tolerances, sealing systems which wear with use and offer limited mating cycles. Technology developers are therefore focusing their efforts on developing new kinds of docking systems with greater capabilities and longer lifespans.
The latest group to tackle the challenge is an international collaborative effort between companies and universities from Brazil, Norway, Poland, Sweden and the UK. The consortium is led by Norway’s WiSub, and includes contributions from Bergen University, DOF Subsea, easySubsea, Federal University of Rio de Janeiro, Kongsberg Maritime, Saab Dynamics, Sonardyne, Statoil, Swire Seabed and Warsaw University of Technology.
In particular the project will draw on WiSub’s expertise in pinless power and data connections, and Brazilian firm easySubsea’s experience in wireless underwater communication. The project was first initiated under a call for joint industry projects (JIPs) by the Research Council of Norway and Brazil’s R&D funding body Finep in 2016 – the first time the two organisations have worked together.
Station to station The goal in this case is to develop a pinless docking station capable of bi-directional data and power transfer. WiSub’s existing pinless systems allow for much higher rates of data transfer through seawater than many rival non-contact subsea communications methods, by using the company’s patented high-frequency microwave electronics (as opposed to other methods such as low-frequency RF, inductive or acoustic protocols). Its technology enables wireless transfer rates of up to 100Mbps, and power transfer of up to 48W/24V.
Pinless technologies also preclude any galvanic separation, allow for greater freedom of alignment, are immune to seal contamination and offer unlimited mating cycles, making them a strong choice for subsea developments. Bi-directional power transfer will also mean AUVs could be used as mobile batteries. For example, AUVs could be dispatched to charge distributed sensor networks from their batteries.