Uncrewed Systems Technology 044 l Xer Technolgies X12 and X8 l Lidar sensors l Stan UGV l USVs insight l AUVSI Xponential 2022 l Cobra Aero A99H l Accession Class USV l Connectors I Oceanology International 2022

6 Mission-critical info for uncrewed systems professionals Platform one A new drive system for flapping-wing autonomous craft has been developed at the University of Bristol, in the UK, using a new method of electromechanical zipping that removes the need for conventional motors and gears (writes Nick Flaherty). Until now, typical micro flying robots have used motors, gears and other complex transmission systems to achieve the up-and-down motion of the wings. That has added complexity, weight and undesired dynamic effects.  The researchers, from the university’s Faculty of Engineering and led by Professor of Robotics Jonathan Rossiter, have successfully demonstrated a direct-drive artificial muscle system, called the Liquid-Amplified Zipping Actuator (LAZA), which achieves wing motion using no rotating parts or gears.  “With the LAZA, we apply electrostatic forces directly on the wing, rather than through a complex and inefficient transmission system,” said Dr Tim Helps, developer of the LAZA system. “That gives better performance, simpler design and will unlock a new class of low-cost, lightweight flapping micro air vehicles for applications such as autonomous inspection of offshore wind turbines.” The researchers developed a pair of 50 mm-long LAZA-powered flapping wings with a specific power of up to 200 W/kg, enough to fly a robot across a room at 18 body lengths per second. The wings provide a net directional thrust of up to 5.73 mN while consuming only 243 mW of power. That gives a thrust-to-power ratio of 23.6 N/kW, similar to state-of-the-art flapping aerial vehicles, helicopter rotors and commercial UAV motors. The researchers also demonstrated how the LAZA can deliver consistent flapping over more than a million cycles, which is important for making flapping UAVs for long-haul flights. This could pave the way for smaller, lighter and more effective micro flying UAVs for applications such as environmental monitoring, search & rescue, and deployment in hazardous environments. By greatly simplifying the flapping mechanism, the LAZA system is expected to enable future miniaturisation of flapping UAVs down to the size of insects. “The LAZA is an important step towards allowing autonomous UAVs to perform environmentally critical tasks such as plant pollination, and emerging roles such as finding people in collapsed buildings,” said Prof Rossiter. Airborne vehicles Miniature flapping drive June/July 2022 | Uncrewed Systems Technology The Liquid-Amplified Zipping Actuator could pave the way for UAVs the size of insects