A passive capture latch for ODYSSEY-class AUVs

Abstract

Under subcontract to the Massachusetts Institute of Techology's (MIT) Sea Grant Autonomous Ocean Sampling Network (AOSN) program, the Woods Hole Oceanographic Institution's Deep Submergence Laboratory (WHOI-DSL) produced a passive capture latch for ODYSSEY -class autonomous underwater vehicles (AUVs). The latch is an all-titanium, split tine device, shock-mounted to the bow of the AUV. When the AUV concludes a survey mission and returns to a moored, midwater docking station, the latch leads the AUV's approach and is the first device to collide with the station's vertical docking pole. Latching to the pole is an entirely passive event requiring only forward motion of the AUV. A positive capture indication generated by proximity switches mounted on the device initiates AUV power and data transfer servicing by the station. Unlatching action requires one revolution of a latch motor cam and a brief backing command to the AUV thruster. The possibility of system malfunction was considered in latch design. If for any reason the latched vehicle canot perform normal unlatching behavior, or the station fails, the latch defaults by securing the AUV to the moored station indefinitely. Two WHOI AUV latches have been used successfully on three offshore engineering test cruises.