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Research of dynamics of double helicoidal vehicle in granular media

A new propulsion principle for underwater vehicles has been developed, inspired by microorganisms in the world of bacteria which use their rotating flagella to generate thrust force. The construction, consisting of two co-axial, leftand right-handed threads that rotate in opposite directions, which is termed double-helicoidal propulsion, and an elastic mid-section, which contains all communications and control mechanisms with a cardan joint, has successfully proven itself not only in water environment, but also shown the capability to perform as an amphibian. The prototype of an autonomous underwater vehicle created at the Institute of Mechanics of the Riga Technical University has shown good agreement with simulation results. Therefore, further studies are being conducted for a vehicle of this propulsion type, which include examination of its ability to move and maneuver in granular media. The main area of implementation for this propulsion type is remote or autonomous devices (robots). Such autonomous robots, which are able to move in granular media, for example, grain hoppers, could be successfully applied in gathering data and diagnostics of the hopper’s internal environment. Equipping this kind of robot with humidity and thermal sensors would allow it to gather and show data in real-time, allowing prevention of potential problems. Discrete element modelling software EDEM was used to model interaction between granular media and moving objects with complicated forms. Simulation results confirm the ability of the patented vehicle to move in granular media that is not particularly dense. In the future it is planned to conduct real environment experiments with a prototype of the vehicle in a grain hopper.