3D UNDERWATER MINE MODELLING IN THE ¡VAMOS! PROJECT

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

Unimolecular ion dissociation and laser-induced coalescence of hydrogenated fullerenes

The ion-fragmentation behaviour of hydrogenated fullerenes has been investigated by tandem mass spectrometry applying sector instrumentation. In addition to the expected loss of hydrogen, unimolecular decay reactions are observed featuring cage rupture by the loss of hydrocarbon moieties. The findings are discussed in comparison with the behaviour of other fullerene derivatives. The gas-phase coalescence reactivity of C60H36 has been studied utilising laser desorption/ionization time-of-flight mass spectrometry. In contrast to pure fullerenes and certain organic fullerene derivatives, hydrogenated fullerenes do not readily undergo laser-induced fusion reactions

Evaluation of the primary and secondary creep of SnPb solder joint using a modified grooved-lap test specimen

The time and temperature dependant creep deformation of solder alloys has to be studied to describe material characteristics and failure behaviour in order to use it for lifetime evaluation by FE-simulations. It is often found in literature that material behaviour of eutectic SnPb solder is described considering only secondary creep. As this paper will show, primary creep may not be neglected because of its appearance in the performed characterisation tests and application examples. To study the creep behaviour, the grooved lap geometry described by Reinikainen was used and additionally modified to see crack and cavities in the solder joint using SAM (Scanning Acoustic Microscope). The test specimen was cyclically loaded for different stress levels and temperatures. Primary and secondary creep was observable under conditions of load reversal. A combined creep law using primary and secondary creep will be presented and an example is shown to highlight the relevance of the primary creep

EVALUATING CONTINUOUS-TIME SLAM USING A PREDEFINED TRAJECTORY PROVIDED BY A ROBOTIC ARM

Recently published approaches to SLAM algorithms process laser sensor measurements and output a map as a point cloud of the environment. Often the actual precision of the map remains unclear, since SLAMalgorithms apply local improvements to the resulting map. Unfortunately, it is not trivial to compare the performance of SLAMalgorithms objectively, especially without an accurate ground truth. This paper presents a novel benchmarking technique that allows to compare a precise map generated with an accurate ground truth trajectory to a map with a manipulated trajectory which was distorted by different forms of noise. The accurate ground truth is acquired by mounting a laser scanner on an industrial robotic arm. The robotic arm is moved on a predefined path while the position and orientation of the end-effector tool are monitored. During this process the 2D profile measurements of the laser scanner are recorded in six degrees of freedom and afterwards used to generate a precise point cloud of the test environment. For benchmarking, an offline continuous-time SLAM algorithm is subsequently applied to remove the inserted distortions. Finally, it is shown that the manipulated point cloud is reversible to its previous state and is slightly improved compared to the original version, since small errors that came into account by imprecise assumptions, sensor noise and calibration errors are removed as well