Biologically inspired chemical plume tracing on an autonomous underwater vehicle

Olfactory-based mechanisms are hypothesized for a variety of biological behaviors. Typically, such hypotheses combine a large-scale olfaction based orientation behavior with a multisensor local search near the source. Long-range olfactory-based search which involves chemical plume tracing is documented in moths at ranges of 100-1000 m and in Antarctic procellariiform seabirds over 1000 km. This article presents a biomimetic algorithm to replicate these chemical plume tracing feats in an autonomous underwater vehicle (AUV). The objective is to locate the stationary source of a chemical that is transported in a turbulent fluid flow. Such AUV capabilities have applicability in searching for environmentally interesting phenomena, hazardous chemicals, and pollutants. This article presents a complete strategy and results from successful, large-scale, in-water tests of this strategy. Amongst other accomplishments, these tests succeeded in tracking a plume 975 m and declaring the source location with 13 m accuracy.