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

114 Until very recently, the only thing able to keep up with an Formula One car around a track was another Formula One car. That is no longer the case. A team of engineers and first-person view (FPV) pilots who modestly style themselves ‘the Dutch Drone Gods’ have succeeded in following and filming triple Formula One world champion Max Verstappen and his Red Bull Racing RB20 around Silverstone, albeit on a wet day (writes Peter Donaldson). Wearing Red Bull livery, the little battery-electric uncrewed aerial vehicle (UAV) boasts a top speed of 350 kph, three minutes of battery life and a 10 km range. It is shaped like an artillery shell, with four short wings set 90° apart around the fuselage in a cruciform layout. In the UAV’s normal flight attitude, the wings resemble a letter X, rather than a plus sign, with the nose-mounted camera oriented down and to the right of the flight path. The wingspan is roughly equal to the fuselage length. Each wing has a propeller on the end and appears to lack any form of movable control surface, implying that the machine is controlled in pitch and yaw using differential thrust, and it doesn’t need to roll to turn. The propellers are small in diameter and have two blades with a significant amount of twist near the root. The blades widen from the root and then taper down to a squared tip, spinning at up to 42,000 rpm. Take-off from the base unit is vertical, and pilot Ralph Hogenbirk (‘Shaggy FPV’) quickly pitches it forward into horizontal flight. It can hover but uses a lot of energy doing so. For the tail-first vertical landing, he points the nose skyward and removes his headset to guide the vehicle to touchdown, like any other RC landing. With the battery delivering a lot of power in a small package, thermal management was always going to be difficult. A critical temperature quickly exceeded the 100 C limit by 20 C in prototype testing, and one flight was cut very short when a wire melted. The team had to work on aerodynamic stability in turns, once resorting to taping joint lines to smooth the airflow. Testing highlighted the necessity to stay clear of an Formula One car’s turbulent wake, which shows up very clearly in the wet. These aerodynamic refinements and material changes plus some reliability tweaks were applied with help from Red Bull Advanced Technologies to create the final version that would make the lap attempt. This machine was shorter and lighter, and featured a better camera. Hogenbirk successfully followed the car around the track, capturing some uniquely impressive footage from the UAV, which had no problem matching the RB20’s speed. The occasional overshoot in braking zones – nothing out-brakes an Formula One car – and some wide lines around tighter corners revealed the difficulty of the pilot’s task, but he kept the car in shot all the way round. The footage is available on the Red Bull Racing website and Formula One fans are in for a treat. April/May 2024 | Uncrewed Systems Technology PS | Red Bull Racing camera missile Now, here’s a thing Wearing Red Bull livery, the little battery-electric UAV boasts a top speed of 350 kph, three minutes of battery life and a 10 km range