Abstract
Underwater experiments with unmanned vehicles are complex, costly, time-consuming and in some circumstances potentially dangerous, involving the risk of losing or damaging the robots. The nature of the underwater environment, makes it very difficult, for researchers, to observe the evolution of the running system. Simulators are useful tools for the development of unmanned vehicle software, algorithm benchmarking and system preliminary validation. In this work, the problem of simulating a complex underwater scenario for marine robotics and a comparative analysis of simulators for marine robotics are presented. Relevant sensors for underwater robots under development, such as multibeam and imaging 2D sonar were implemented in two simulators and tested in a realistic experimental scenario like a flooded mine.

Abstract
The project Viable Alternative Mine Operating System (¡VAMOS!) develops a novel underwater mining technique for extracting inland mineral deposits in flooded open-cut mines. From a floating launch and recovery vessel a remotely-operated underwater mining vehicle with a roadheader cutting machine is deployed. The cut material is transported to the surface via a flexible riser hose. Since there is no direct intervisibility between the operator and the mining machine, the data of the sensor systems can only be perceived via a computer interface. Therefore, part of the efforts in the project focus on enhancing the situational awareness of the operator by providing a 3D model of the mine combined with representations of the mining equipment and sensor data. We present a method how a positioning and navigation system, perception system and mapping system can be used to create a replica of the physical system and mine environment in Virtual Reality (VR) in order to assist remote control. This approach is beneficial because it allows visualizing different sensor information and data in a consistent interface, and enables showing the complete context of the mining site even if only part of the mine is currently observed by surveying equipment. We demonstrate how the system is used during tele-operation and show results achieved during the field trials of the complete system in Silvermines, Ireland. © 2019 Copernicus GmbH. All righhts reserved.