A contribution from Christian Burlet, Geological Survey of Belgium (GSB) / Royal Belgian-Institute of Natural Sciences (RBINS)
During April, May and June, the first ‘proof of concept’ experiment was planned at RBINS, to demonstrate the use of LIBS (Laser-induced breakdown Spectroscopy) to perform real-time diagnostics on drilling slurries inside the mineralogical module of ROBOMINERS.
LIBS (Laser-Induced Breakdown Spectroscopy) is an emission spectroscopy technique that uses high-energy laser pulses to induce a plasma from solid, liquid or gas samples. The plasma emits specific light wavelengths related to the chemical composition of the target material with specific spectral lines for each element contained in the plasma and thus in the sample.
Using a LIBS spectrometer inside a working robotic miner and process it in real-time to achieve some degree of selective mining presents many challenges. Being in confinement for an undetermined amount of time, I decided to move some equipment home to be able to continue prototyping hardware and software. It turned out that with a few basic tools and a desktop 3D printer, it is totally possible to keep busy for weeks testing and adapting as many setups as possible and comparing the results like in a real lab!
Example of a 3D printed optical piece designed and 3D printed at home (here the LIBS head with holes for LED lights and synchronization detector)
From mid-March to the end of April, I decided to focus on an experimental LIBS spectrometer that will be used to acquire libs scans of geological samples and cores. In the project, we planned to base this LIBS scanner on a full sized Computer Numerical Control (CNC) machine (ordered but not yet delivered due to the pandemic), as a backup solution, a small cheap CNC device served as a base for the first version of the scanner. During the 2 months of confinement, the small CNC was beefed-up with new motors, and a new custom “Z-axis” was designed from scratch and 3D-printed to fit the optical components (see the evolution of the LIBS scanner in pictures).
Evolutions of the ROBOMINERS LIBS scanner during March-April 2020
Powered by the open-source GRBL software, and a custom python script, the CNC allows a 1.25µm displacement resolution of the spectrometer head, with a repeatability that seems of a few microns (to be verified with SEM imagery later-on). One of the main goals of this experiment was to test a series of optical configurations to get the best signal from the sample, including a good UV signal collection in a so-called LIBS “co-linear” configuration. This configuration needs a custom optical part, a 45° pieced aluminium mirror. Unfortunately, after contacting the manufacturer, this kind of custom part could not be ordered, as the workshops were closed for an undetermined time. Another homemade solution was found, temporarily remounting the CNC to its original purpose and installing it in my kitchen’s apartment in order to drill a hole on a stock mirror as precisely as possible with a diamond bit. After hours of setup and tests, the result was not perfect but totally usable!
Optical kitchen: Making the custom mirror at home
The first spectra acquired (a linear scan on Cu-Co ore sample lying around) are extremely promising, with an excellent signal in the UV (200-400nm), both in collinear and angular collection configuration (see spectra examples).
The next big step is to perform a 1D and 2D LIBS scans data treatment and produce chemical profiles and imagery of ROBOMINERS analogue samples.
LIBS spectra examples
The ROBOMINERS video has just been launched! It is presented this week at the EU booth at PDAC (booth 7123N). If you don’t have the occasion to drop by, watch the video here:
ROBOMINERS partners from the Montan Universität Leoben, Tampere University and TalTech recently met in Leoben (Austria) for a workshop about different options for the production tools of the robot miner, the water-hydraulic power train system and the locomotion. The partners then travelled to Mittersill in Salzburg to visit the local tungsten mine. This tungsten mine […]
On 14 and 15 January 2020, the partners of the EU-funded ROBOMINERS project gathered in Tallinn, Estonia, to discuss the current state of work and define potential scenarios for the robot miner design and application, taking into consideration both economic and political factors such as the need for certain commodities or their criticality in the EU. By developing a bio-inspired robot for mining deposits that are small or difficult to access, ROBOMINERS aims at facilitating EU access to mineral raw materials – including those that are considered as strategic or critical for the energy transition – from domestic resources, and thus decreasing the European import dependency.
The first day, the partners updated each other about the progress of their investigations with a focus on the locomotion of the bio-inspired robot, the future miner’s design and the robot platform’s software. Some of the key aspects involved the robot’s water hydraulics, artificial muscles, pressure compensation, the cutter head system and the power system. Towards the end of the project, ROBOMINERS aims indeed at presenting a full-scale prototype which will demonstrate the mining process.
The experts from the robotics community also presented their draft concept for the robot, whereas the geology and mining experts came up with a preliminary selection of mineral deposit types and scenarios appropriate for the ROBOMINERS technology. Based on a genetic classification of ore types, participants ranked deposits according to the most relevant aspects such as geometry, rock mechanics, stability, extractability and economics. The partners listed different scenarios as well as potential test sites. These scenarios involve ultra-deep deposits; small, non-economic deposits with a minimum surface footprint; hazardous or not accessible environments; and abandoned mines or non-economic parts of operating mines. The final classification of the scenarios and deposit types is expected to be available in spring 2020.
On 15 January, the consortium meeting continued with a workshop on bio-inspired legged locomotion where robotic experts from TalTech University and the Universidad Politécnica de Madrid (UPM) shared highlights of their current research considered as relevant for the development of the robot miner. This included the presentation of different bio-inspired robotic concepts and various legged robots and their technical complexity by the TalTech team. Specialists from UPM presented a modular climber robot planned to be used for infrastructure inspections which has a variable number of legs and can reassemble its modules autonomously. The workshop concluded with a presentation by ROBOMINERS coordinator Claudio Rossi on energy efficient legged locomotion.
This highly technical session was followed by an Advisory Board meeting involving external experts from the mining industry, and an interactive roadmapping workshop led by La Palma Research Centre for Future Studies (LPRC). The participants discussed the 2030 and 2050 horizon for ROBOMINERS in close alignment with the EU policy vision. The input received will be used for further foresight exercises. The meeting concluded with a guided visit at the Centre for Biorobotics of TalTech University.
The fourth edition of the EU Raw Materials Week took place from 18 to 22 November 2019 in Brussels. The event organised by the European Commission addresses the latest news on raw materials in the EU and is a unique opportunity for the raw materials community to exchange on all relevant issues: policy, technology, international cooperation, framework conditions, knowledge base etc.
ROBOMINERS has been presented at this occasion with a poster submission. Vitor Correia (EFG) was available to explain the project concept to the visitors. ROBOMINERS brochures have also been distributed at several of the sessions organised throughout the week.
ROBOMINERS has been presented on 8 November 2019 during the 29th National conference “Actualities and perspectives of minerals economy” (6-8 November 2019) organised by the Mineral and Energy Economy Research Institute Polish Academy of Science (MEERI PAS). The poster was presented by Alicja Kot-Niewiadomska (MEERI PAS).
ROBOMINERS has been presented at the Universidad Politécnica de Madrid last Friday, 8 November 2019 at the occasion of the 10th anniversary of the foundation of the Centre for Automation and Robotics UPM-CSIC. The anniversary event took place in the framework of the Madrid Science Week. The Science Week offers the public the opportunity to learn about the work of scientists, their research, motivations and efforts. It allows society to know the latest advances in science.
The UPM-CSIC team has presented at this occasion a prototype of a reconfigurable modular robot.
During a short visit of the CNES-IRAP laboratory in Toulouse, France, the ROBOMINERS team from the Geological Survey of Belgium presented this summer the project concept and the potential links with the robotic exploration of Mars, involving among others the use of automated LIBS instrumentation, Raman. The discussions led to various technical considerations for the application of spectroscopic techniques from a robotic platform.
ROBOMINERS has been presented on 4 October 2019 during the 30th International conference of the Slovak Mining Society “The present and future of mining and geology”. The title of the oral presentation by Alicja Kot-Niewiadomska (MEERI PAS) was “ROBOMINERS Project – the future of effective mining”. The conference focused on minerals exploitation, processing and use in relation to the environment, an implementation of „zero-footprint mining“ principles, and environmentally friendly production approach „mine-to-mill“ and research, development and application trends in the fields of geology, extraction and processing.