A concept of distributed compact AUV groups for the continuous monitoring of coastal sea environment

In this paper, we present a concept for underwater monitoring of coastal sea area using many compact AUV groups distributed in target area from the surface to the bottom. The underwater continuous monitoring of that area becomes increasingly important related to such field as water pollution investigation, aquaculture control, or coral reef research, etc. The target monitoring area is sliced planar hierarchically toward the depth as monitoring layers, and a group of AUV arranged on each layer tracks the given trajectory and gathers various environmental information continuously communicating each other in the layer or between other layers. There are also autonomous moving buoys on the surface that have the role not only of the observation around surface environment but also of the communication interfaces between underwater groups and facilities on land, satellites etc. We are now making up a basin experiment system for the development of those AUV group technologies. In this paper we introduce a prototype AUV module and ultrasound ranging system just we developed for the experiment in basin or calm sea to examine AUV group control and communications. The prototype AUV is designed as light weighted, small and low-cost as possible to handle it by 2 men conveying them by small fishing boat with no exclusive facilities. The basin experiment to verify the prototype AUV facilities and ultrasound ranging for position detection was carried out