Unmanned Systems Technology Dec/Jan 2020 | Phoenix UAS | Sonar focus | Construction insight | InterGeo 2019 | Supacat ATMP | Adelan fuel cell | Oregon tour | DSEI 2019 | Copperstone Helix | Power management focus

86 Tests and results Upon returning to the launch and recovery site, software signal-return tests are conducted to ensure that the vehicle is safe to approach (in terms of its active mechanical and electrical systems). An emergency-stop command can be sent from the GCS in case the operators and researchers identify an unexpected movement or release of energy. Occasionally, the Helix and some of its equipment are washed down to remove mud and waste. Being waterproof, this poses no danger to the rover. To analyse the samples, Copperstone uses a pumping system to feed them into an online analyser. Both the pumps and analysers are industry-standard tools that the company brings to its operations. The client’s researchers use them to test the tailings for variables such as dissolved oxygen levels, dissolved solids, fluorescence, hydrocarbon content or hyperspectral imaging of soils, which can help reveal the mineral or moisture content, in a similar way to UAV agricultural surveys. Data collected on location can then be delivered to off-site laboratories for further analysis if needed. The actual location of the analysis equipment could be in a field laboratory near the launch and recovery site, or it could be integrated onto the Helix’s platform for in-situ analysis. The latter would particularly suit the AR2, given its larger payload area and battery capacity. “It would depend on the client’s needs and the time value of the analytical information,” Lipsett says. “We could then have an analyser custom-designed to fit the ideal footprint for integration on the rover.” In the future, the rover could act as a self-sufficient unmanned mobile laboratory on the water and the shore, with only the operator and technicians needing to be on site to deliver, retrieve and maintain the vehicle. Automating tests could also remove operator variability and human error, enabling more consistent and accurate results of analyses. The time taken for a sampling mission is highly client-dependent, varying from a few days to several weeks according to the number of surveys, samples and measurements required, as well as the rover’s route to and from a sampling region. Between sampling missions, the rover can have its batteries charged or swapped out. A generator and charger station are often taken on location to ensure the swapped out pack can be fully recharged in the time it takes for the swapped-in one to become discharged. Sampling payloads, geotechnical tools and survey and analysis systems can also be unfastened and swapped out – which usually takes no more than 10 minutes – to conduct field operations across different waters and terrains. A maintenance checklist is run through before the Helix sets off again. That includes tests on electrical connections, inspections for damage to components and searching log files to check for any performance anomalies. The future Copperstone sees many other uses for the Helix 25 and AR2, including detecting and destroying unexploded ordinance on beaches. Other mine tailings, such as those from extracting iron ore, have also been successfully collected and tested, and rice paddies or shrimp farms could be sampled to measure the nutritional content of the water and soil. December/January 2020 | Unmanned Systems Technology In operation | Copperstone Helix amphibious vehicles Helix 25 Size: 145 x 90 x 62 cm Weight: 45 kg Payload and battery capacity: 25 kg Top speed: 7.2 kph Operating speed: 1.8 kph Maximum endurance: 14 h Range: 25 km Some key suppliers Machining: Caprice Machine Works Motors: Midwest Motion Products Bathymetric sensors: Airmar Ground control station hardware: Panasonic (customised) Ground control station software: QGroundControl (customised) GNSS: Hemisphere Fasteners: McMaster-Carr Metal: Metal Supermarkets Specifications The central mast enables survey payloads to be lowered underwater, and sampling payloads to be pushed into mud