Active Buoyancy Control

The ability to actively control the buoyancy of underwater sea gliders could greatly enhance the efficiency of the underwater vehicles. Both large displacements as well as small (trim) displacements are beneficial to finely control the buoyancy of the sea glider. For Phase I Mide proposed and showed that it is feasible to utilize either shape memory allow (SMA) dimples, or super elastic alloy (SEA) dimples of varying size, to alter the volume of the craft at select locations, thus altering the buoyancy of the sea glider. In their non-actuated state the dimples when actuated create small mounds on the body of the sea glider. Phase I also developed and demonstrated a novel multi-layered actuator that can be used for buoyancy control in deep water.In the base effort of the Phase II, Mide is proposing to develop both a shallow and a deep water SMA buoyancy actuator and to test these actuators in pressurized water tanks. These actuators will be integrated into a buoyancy control system and tested in the pressurized water tanks. In the Phase II option effort, Midé is proposing to re-design both the shallow and deep systems using the knowledge gained in the base effort and to demonstrate them on a sea glider. BENEFITS: The primary commercial benefit of this technology is in the efficiency improvements of under water gliders. This technology will lower the operating cost of these gliders. If proven successful this technology could span to other platforms that would have a significant impact on the Navy. All commercial submersibles, used in research, surveying and exploration will benefit from this technology.