Experimental validation of the modeling and control of a multibody underwater vehicle manipulator system for sea mining exploration

This paper presents the modeling approach and the control framework developed for the ROBUST EU Horizon 2020 project. The goal of this project is to showcase technologies and methodologies for future autonomous mineral exploration missions in deep-sea sites with an Underwater Vehicle-Manipulator System. Within the aim to make the system reliable in performing autonomously the entire mission, specific modeling, navigation, and control solutions are proposed. In particular, the multihull vehicle hydrodynamic model is derived and experimentally validated, and then used in the implementation of the navigation filter which provides the necessary feedback for the control framework. The latter computes, using a task priority approach, the reference system velocity and control forces for enabling the system desired behaviors. The overall navigation-control architecture has been validated through several sea trials, leading to the final experimental campaign held in Cagliari, Sardinia, Italy, in October 2019, where the overall ROBUST mission was demonstrated. The obtained results are reported to show the effectiveness of the developed framework.