Unmanned Underwater Vehicles

The ocean covers about 70% of the Earth. Ocean-related activities are extremely diverse—aquaculture, commercial fishing, ocean research, seafood marketing, ocean recreation, marine mining, marine biotechnology, and ocean energy. Living and nonliving resources of the ocean are abundant. For example, it is estimated that there are about 2000 billion tons of manganese nodules on the floor of the Pacific Ocean near the Hawaiian Islands. The ocean also plays a critical role in global environmental issues such as pollution and carbon cycles and the ocean retains more heat than the atmosphere. Therefore, it is not difficult to predict that the ocean will have a great effect on the future existence of all human beings. In spite of its importance, the ocean is generally overlooked as we focus more of our attention on land and atmospheric issues, and we have not been able to explore the full depths of the ocean and its resources. We discovered, by using manned submersibles, that a large amount of carbon dioxide comes from the seafloor and extraordinary groups of organisms living in hydrothermal vent areas. Underwater vehicles can help us better understand marine and other environmental issues, protect our ocean resources from pollution, and efficiently utilize them for human welfare. However, ocean travel is difficult because of unpredictable and hazardous undersea environments. Keywords: ROV ; AUV ; control; navigation; sensors; communications; power systems; thrusters; manipulators