MechChem Africa March-April 2024

⎪ Innovative engineering ⎪

Left: A VR-headset can be used to simulate underground emergency scenarios that help psycho-emotional responses to kick in, which we use to ensure trainees keep cool heads. Right: The CSIR’s TMM (trackless mobile machinery) as digital twin-based system looks at how vehicles move around a mine and, most importantly, how they interact with each other.

tions are identified, researched, developed and coded. He says South African gold and platinum ore bodies are narrow and tabular in nature, with a small stoping width making it difficult to identify rock related hazards and hazardous practices in the confined space. Anything that can assist the mines, and specifically the rock engineering practitioners to design, assess, record and report underground conditions, installed support and general mining prac tices more efficiently and reliably, contrib utes towards a safer and more productive environment. Lastly, Riaan Bergh pointed towards current CSIR research partly funded by CoalTech: the use of a drone platform for Ground Penetrating Radar. “GPR is widely accepted for assessing the safety of mine walkways, for example, which may have areas of subsid ence. Traditionally, this is done using a radar antenna mounted on a trolley that has to be wheeled across the surface being assessed,” he explains. “By mounting the radar antenna onto a drone, we are able to set up a flight path to safely cover inspection areas that are difficult or hazardous to access on foot in a fraction of the time that it would take ground-based crews. The digital data is then used to create a report of the ground condition, enabling its condition and reparation needs to be assessed quickly,” he says “Many people think that the focus on safety involves making sacrifices elsewhere. That is certainly the case in some instances, but in many cases, we have shown that the application of virtual reality, digital twins and other innovative tools can help to improve both safety and productivity at the same time,” Riaan Bergh concludes. www.csir.co.za Drone mounted Ground Penetrating Radar (GPR)

to give people a real experience of what it feels like to wear and use one. “These are single use devices, though, whereas our Expectation Trainer can easily be disinfected and used again – and they are much less expensive than a complete functioning self-rescuer device, so a mine’s whole workforce can be put through expectation training,” he says. The last aspect of CSIR’s competency based training is putting all of the developed competencies together in a realistic environ ment: “We take trainees into a mock up mine and create an emergency scenario. The lights go out, we blow in smoke and blast disaster type noises through a sound system, for ex ample. The trainees then need to open and put on their self-rescuers and follow the lifeline to the refuge chamber, all without panic and while doing all the necessary safety checks. Successful completion of the ‘escape’ suggests that the trainee is safety competent and has a good chance of surviving a real emergency,” says Bergh. Another innovation on show was a digital twin development for collision prevention of track less mobile machinery (TMM): “In the virtual environment on a cloud platform, we are able to recreate a digital twin of a mine’s whole operations with respect to traffic flow. The system looks at how vehicles move around a mine and, most importantly, how they interact with each other,” Bergh explains. The initial motivation for the system was driven by transport-related accidents, hence Chapter Eight Regulations of the Mine Health and Safety Act, which states that wherever there is a significant risk of collision, mine vehicles needs to be fitted with a fail-safe machine intervention system that can slow and stop the vehicle autonomously (as per Level-9 of Earth Moving Machine Safety Round Table’s defensive layers of control). The digital twin for trackless mobile machines

To install this system on all the vehicles in a mine is prohibitively expensive, though. “So the digital twin was developed to assist in quantifying collision risks, non-conformances, and identifying vehicles most at risk. The system collects actual GPS data from mobile machines and uses numerical models and machine learning to model the movement of the vehicles and derive vehicle-interactions and non-conformance insights, helping mine operators to make informed choices about risk mitigation and/or accurately identifying which vehicles need Level-9 intervention technology,” he says. “Also, though, it quickly became clear that we could also use the system as a productivity optimisation tool, because in the same way as you can model risk outcomes, we can also op timise traffic management, say, by monitoring speed, route, or dispatching parameters, for example. By doing so, we can see which sce nario gives the best productivity outcome for the whole system, so instead of simply iden tifying collision-risk vehicles, we are able to optimise operations for a mine’s entire mobile vehicle fleet,” Bergh tells MechChem Africa. Rock Engineers Assistant (REA) Bergh went on to describe another digital solution being developed for Industry, which consists of a platform that will run a number of applications aimed specifically to assist rock engineering practitioners. “This solution origi nates from one of our own rock engineers with inside knowledge of the difficulties involved with implementing rock engineering related practices on the mines”. REA aims to assist the practitioner in iden tifying underground hazardous conditions or situations by considering several related data sources simultaneously and will eventually also assist with technical development and with some typical calculations performed by rock engineers. The REA platform is planned to continuously expand as additional applica

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