Inductive Power System for Autonomous Underwater Vehicles

Underwater inductive coupling is used to recharge a lithium-ion battery pack for an underwater mooring profiler operating on a cabled deep-ocean mooring sensor network. The mooring profiler is a motor driven autonomous underwater vehicle that is attached to a vertical mooring cable suspended between the seafloor at 900 m and subsurface float structure at a depth of 160 m (to minimize wave dynamics and bio-fouling). A suite of on-board sensors record data as the mooring profiler travels along the cable which is transferred from the profiler to the sensor network and ultimately to shore over an inductive data link. The on-board batteries are charged inductively when the profiler enters a dock mounted below the float. Power transfer across the inductive couplers is approximately 240 W with 70% efficiency.