Artificial Fish: AUVs Designed to Model Animals :: Autonomous Undersea Vehicles Fish Essays

Artificial Fish: AUVs Designed to Model Animals Humans venture beneath the ocean's surface to collect resources, conduct research, engage in warfare, and perform countless other tasks. The need for increasingly specialized technology to accomplish these tasks has prompted the development of many different designs of submersibles, varying from manned nuclear submarines to Remotely Operated Vehicles (ROVs) dragged behind surface ships, to untethered Autonomous Undersea Vehicles (AUVs) (Blidberg 1). This last design, the AUV, has received special attention in recent years as humans explore greater and greater depths. As its name suggests, the AUV functions independently, without intervention from a human operator. It carries its own power source (traditionally a battery), and receives all its commands from an onboard computer, thus involving some degree of artificial intelligence. This computer serves to direct the robotic submersible in performing a pre-defined task. Because its movement is not restricted by a cable connec ting it to a mother ship, the AUV is ideal for operating in hazardous areas and at great depths. Current and proposed activities for AUVs include undersea exploration, scientific sampling of physical oceanic conditions (such as salinity level and temperature), laying and inspection of gas lines and cables, searching for downed aircraft, and mine reconnaissance (Canfield, Hylands). A key aspect of common AUV design, however, prevents this list of activities from expanding and limit the current potential of AUV performance. Due to the inefficiency of propulsion and power systems, AUVs are highly unstable in any turbulent water, are limited to short missions, can carry only small payloads, and have little maneuvering control at low speeds (MIT, Canfield). In the most unfavorable of conditions, AUVs may not even be able to reach their intended destinations while traveling at slow speeds, despite the use of slow speed guidance systems (Healey 335). Small rotary propellers plagued with low efficiency and lagged response times typically power AUVs (MIT). Furthermore, batteries often require 70% of the hull space (MIT). Closely tied to efficiency of propulsion systems is the hydrodynamic shape of the submersible's hull. While hull designs have improved over time, they do not compare to the hydrodynamic efficiency of fish and aquatic mammal shapes. As Jeff Walker, a biology professor at the University of Southern Maine, stated, "It's a lofty goal for a human-made vehicle to achieve the performance of a fish" (qtd.