Resident AUV Design for Deployment at Kilo Nalu Observatory

Near-shore environments are important to oceanographers because of their relationship to the biogeochemical and anthropogenic processes which occur on land and at sea. Their proximity to land makes them convenient to study long-term using undersea infrastructure, which can supply oceanographic sensor arrays with power and data connections. However, such infrastructure is fixed and cannot adapt to interesting chance events like autonomous underwater vehicles (AUVs) can. AUVs, on the other hand, cannot stay in the water forever and need intervention before embarking on new missions. Here, we present the design of a resident AUV coupled to the undersea infrastructure at Kilo Nalu Observatory (KNO), a near-shore observatory off the south coast of Honolulu, Hawaii. We modify the BlueROV2 Heavy, a commercial ROV sold by BlueRobotics, to create our relatively low-cost resident AUV. Among the novel features we add to our resident AUV are a larger pressure vessel, a gimbaled camera, larger thrusters, and an inductive charging module to be paired with a docking station connected to KNO's undersea infrastructure. In the future, we will field test the AUV to fully overcome the challenges of autonomous docking and charging in near-shore environments and demonstrate the feasibility of long-term resident AUV deployment. Moreover, we intend to remove the AUV's reliance on undersea infrastructure and move towards resident AUV operation in information-rich, low accessibility areas.