Chemical Plume Tracing And Localization Via An Autonomous Underwater Vehicle In A Turbulent Fluid Flow Environment

Hydrothermal vent systems are the plumbing systems of the deep ocean, spewing heat and minerals from Earth's interior while supporting unique ecosystems and offering clues about the geological processes that regulate the formation of oceanic crust. Locating and mapping the distribution of hydrothermal plumes near the venting sources assists the geochemists optimize their efforts to study the evolution of dissolved and particulate components of vent emissions by helping them determine the best locations and depths to take water samples.Historically, hydrothermal vent discovery were primarily performed by the human occupied submersible vehicles or tethered vehicles. In recent years, the value of employing an autonomous underwater vehicle (AUV) as a complementary tool for hydrothermal vent discovery has been demonstrated on several successful expeditions in both the Pacific and Atlantic Oceans. AUVs use hydrothermal chemical signature as a guide to navigate and track in the unknown environments.This thesis focuses on the problem of using an AUV to find a hydrothermal chemical plume, trace the hydrothermal chemical plume to its source. The relatively detailed work can be concluded as follows:1. The distribution and evolution of the chemical plume in the turbulent fluid are analyzed. Then the chemical plume simulation environment program is developed.2. Explain in detail the process of the behavior-based planning for AUV tracing and locating the chemical plume in turbulent fluid.3. Propose the Artificial Potential Field (APF) methods for tracing and locating the chemical plume.4. Present the simulation results based on the behavior-based planning and APF methods.From the research work above, the author can draw the conclusion that the search methods studied are feasible and effective for chemical plume tracing via AUV in a turbulent fluid.