Motion Control of Underwater Mine Explorer Robot UX-1: Field Trials

Abstract

In this paper, we present the results of a series of field trials conducted with an underwater vehicle in the increasingly complex underwater environments of the Kaatiala mine in Finland, the Idrija mine in Slovenia, and the Urgeiriça mine in Portugal. These field experiments have been performed to test and validate the motion control systems of the underwater explorer robot (UX-1), which are: a variable ballast system for buoyancy control, a variable pitch system for pitch control, and a propulsion system for depth and heading stabilization. The control method implemented is based on a state feedback linearization algorithm, previously tested and validated in a controlled water tank environment. Several experiments are shown which demonstrate the successful operation of the motion control systems in individual performance tests. Afterward, a full exploration and geo-scientific data collection mission is presented, where all of the motion control systems are active simultaneously during a deep dive to more than 100 m. The results obtained in the field tests demonstrate the effectiveness of the motion control systems and validate the UX-1 Robot platform as capable of performing the complex task of navigation and control in flooded mine environments.

A Review of Underwater Robot Localization in Confined Spaces

“…To mitigate the effects of water turbidity and environmental light on positioning, the UX-1 utilized a fusion of IMU and DVL for localization. The research team conducted underwater tests of the UX-1 in June 2018, September 2018, and March 2019, respectively, at the pegmatite mine Kaatiala, the mercury mine at Idrija, and the uranium mine of Urgeiriça in Portugal [10]. Among these three underwater mines, the pegmatite mine Kaatiala exhibited the most optimal underwater environment with clear water quality and simple mine structures, while the mercury mine at Idrija and the uranium mine of Urgeiriça both had turbid water and complex mine structures.…”

Functional Self-Awareness and Metacontrol for Underwater Robot Autonomy

“…Underwater Robotic Vehicles (URV) are usually divided into two categories, Remotely Operated Underwater Vehicles (ROV) and Unmanned Underwater Vehicles (UUV). Although UUVs are more restricted in terms of operation and power consumption, they are more autonomous and maneuverable because of their control capabilities [ 37 , 38 ].…”

Design and Testing of a Spherical Autonomous Underwater Vehicle for Shipwreck Interior Exploration

“…The UX−1, developed by Fernandez et al (ca. 2016), for the European Union's UNEXMIN Project, is a novel, spherical AUV designed for the exploration of flooded mines [54][55][56][57][58][59][60]. The early prototype was a smaller platform than the final, sophisticated version completed several years later (described earlier in this subsection).…”