Visibility improvement in relation to turbidity and distance, and application to docking

Recently, autonomous underwater vehicles (AUVs) are being used in many applications. There is a limitation for underwater vehicle’s operation that takes a longer duration than the power capacity of underwater vehicles. Since underwater battery recharging station is supposed to be installed in the deep-sea bottom, the deep-sea docking experiments cannot avoid turbidity and dark environment. In this study, we propose a newly designed active 3D marker to improve the visibility of the 3D marker. A docking experiment apparatus was built. Two kinds of the 3D marker were used in the experiment, which were the active (light) and passive (non-light) 3D markers. The experimental results show the active 3D marker can be more recognizable in turbidity and dark environment than the passive 3D marker.