Issue 55 Uncrewed Systems Technology Apr/May 2024 Sellafield’s UAV equipment l Applied EV Blanc Robot l Battery tech l Robotican’s Goshawk l UGVs l UAVHE RW1 rotary l Roboat UVD l Autopilots l Arkeocean UVD l UMEX 2024 l CycloTech UVD

108 There is a lot of overlap between uncrewed aerial vehicles (UAVs) and electric vehicle take-off and landing (eVTOL) aircraft intended to carry people, most of which is a result of technology transfer from one to the other. In the case of CycloTech, and its radical CycloRotor propulsion and control system, however, it is a new technology under development for both, even though early engineering work and flight testing is focused on uncrewed prototypes, the latest being the Bumblebee 2.0. The CycloRotor is an adaptation of a concept developed almost a century ago and successfully applied to ships – the Voith Schneider cycloidal propeller, which uses vertically mounted blades arranged in a circle that revolve around a common centre and change pitch cyclically in concert to direct their thrust in any direction around their axis of rotation. In this way, the propeller provides both propulsion and steering. It is used in ships that need to manoeuvre in tight spaces, follow a course precisely at low speed at sea or hold an exact position against strong currents. Common applications include ferries, tugs, cable layers, drill ships, offshore construction vessels, buoy tenders and river cruise ships. The idea to apply this concept to an aircraft occurred to CycloTech’s founder, Meinhard Schwaiger, in the early 2000s while stuck in a Moscow traffic jam. “He was convinced that things had to change for the better and that using the third dimension as additional axis for mobility would bring the expected relief,” says chief development officer Markus Steinke. “When researching technical options, he found the cycloidal rotor the most promising.” Schweiger founded the company in Linz, Austria in 2004. The main differences between a CycloRotor (also known as a cyclogyro rotor) and the Voith Schneider propeller Peter Donaldson explores a unique flight system inspired by a century-old water propeller Flight of the Bumblebee April/May 2024 | Uncrewed Systems Technology Bumblebee 2.0, seen from the front. Each of the four cycloidal rotors can instantly direct its thrust in any direction at 90o to its axis of rotation, providing control in all six axes of motion (Image courtesy of CycloTech)