DIY drones: local UAV gurus push the tech limits of civilian flyers

  • The Freedom drone, developed by four Cape Town-based amateur UAV flyers, is almost ready for production. This decidedly battered Mk III Freedom, owned by Willie Prinsloo, bears the scars of the team’s rigorous R&D process. Image credit: Sean Woods
  • The brushless, pan/tilt camera gimbal that comes packaged with each Freedom drone was designed in-house by Daniel Soobramoney. Image credit: Sean Woods
  • Soobramoney, the techie of the team, came up with the idea to incorporate the circuit boards into the drone’s fuselage. Image credit: Sean Woods
  • An ardent First Person View (FPV) flyer can think of nothing better than donning his goggles and exploring the world via his drone’s forward-facing HD video camera. Image credit: Sean Woods
  • Hein du Plessis, a dedicated fixed-wing drone flyer, can monitor what his drone’s seeing from up to 20 km away. Image credit: Sean Woods
  • Hein sets up his mobile ground station, including a home-made bi-quad antenna. Image credit: Sean Woods
  • Hein’s Skywalker drone boasts a range of about 80 km, can remain airborne for up to 2 hours, and carries three cameras. Image credit: Sean Woods
  • The Freedom drone, developed by FPVSA, is a robust, practical, purely South African drone that can be quickly packed into a suitcase without being dismantled. It features built-in FPV functionality, a brushless gimbal (giving smooth, almost-professional pan and tilt functionality to small compact cameras) and will cost under R20 000 RTF (ready to fly). Image credit: Sean Woods
  • Image credit: Sean Woods Image credit: Sean Woods
  • The team’s resident film-maker, Glen Thomas, in his workshop. Image credit: Sean Woods
Date:21 November 2013 Author: Sean Woods Tags:, ,

Drones. Love them or hate them, they’re here to stay. Critics fear Big Brother-like control and compromised personal and professional privacy. Supporters dismiss these suspicions as paranoia, claiming the positive contributions made by civilian UAVs (unmanned aerial vehicles) to society far outweigh any negative military/spy connotations.

Here at home, there’s plenty happening on the UAV front. University researchers are working out how to land them on moving ships (at night!) and determining how they could be deployed to help farmers manage their crops. Small start-ups are starting to make useful money by producing hobbyist machines for export via the Internet. Looking for a heavy lifter that’s capable of lofting a pro-quality camera? No problem. (In the latter case, though, you’d better be prepared to spend big bucks.)

It’s no surprise that hobbyists, photographers, ex-radio control flyers and the like have been bitten by the drone bug. Many of them have become highly proficient flyers, shifting their focus to technological innovation and useful, sometimes counter-intuitive applications. As they improve their skills and upgrade their gear, they’re exchanging ideas with like-minded enthusiasts all over the world and pushing drone technologies to the limit – and occasionally beyond it. Over time, this backyard development and experimentation has led to interesting online collaborations. And in some groups, magic is happening…

Common ground
One such group calls itself FPV-SA (First Person View South Africa). It comprises a bunch of guys who can think of nothing cooler than donning goggles and getting a bird’s eye view of the world via a drone’s on-board HD video camera. They actually have an advantage over birds in the form of a real-time flight telemetry display, which allows them to orient themselves without having to glance away. They’re able to monitor compass bearing, speed, altitude, banking angle, distance, an artificial horizon, direction to home, and more. It’s a bit like seeing the world through the eyes of a Skynet robot, not to mention being completely addictive.

It was this common interest that drew together four of the group’s Cape Town-based members – Glen Thomas, Willie Prinsloo, Hein du Plessis and Daniel Soobramoney. They wanted to develop a robust, practical, authentically South African drone that could be packed into a suitcase quickly and easily (that is, without being dismantled), and carried anywhere.

Needless to say, built-in FPV functionality was a must, as was a brushless gimbal that would deliver smooth, near-professional pan-and-tilt functionality for compact cameras.

Intent on keeping it affordable, they resolved to create a system that would sell in RTF (ready to fly) form for under R20 000. And they did it: their quadcopter, aptly named Freedom, is almost ready for production.

Now that the Freedom project is coming to an end, the team is beginning to eye other opportunities – and they like what they see. Thomas elaborates: “We want to make UAVs practical working tools, not just hobbyist toys. What excites us is long-range flying, because this is what will allow drones to make a real positive impact in our lives.” Projects on FPV-SA’s immediate radar include sea- and mountain rescue and anti-poaching surveillance. Next up: fire spotting, game counting, irradiated moth deployment and crop spraying… the list of potential applications continues to grow.

Melding of minds
They’re clearly unfazed by the challenges, and in fact they’re making pretty good progress. Du Plessis, using his home-built bi-quad antenna, can already maintain a steady video link over distances of up to 20 km. His hand-launched, fixed-wing Skywalker drone has a 3 kg carrying capacity and a range of about 80 km, and can remain airborne for up to two hours. It’s also a serious camera-carrier, being equipped with the obligatory forward-facing FPV video camera, a GoPro action cam mounted on a brushless gimbal with full pan-and-tilt capability, and a third camera, attached to the fuselage with Velcro, that is positioned to point forwards, backwards or straight down, depending on what’s needed.

It takes Du Plessis about 10 minutes to set up and get airborne. Everything can be viewed on his mobile ground station’s monitor. The feed from all cameras is saved automatically on a computer, and everything can be controlled (including the management of waypoints) via any Android device or laptop. It’s a formidably efficient set-up, and it works. Says Du Plessis: “I’m talking to Karoo sheep farmers who are completely fed up with stock theft in their area. They’re considering pooling their resources and getting a drone fitted with an infrared camera for night patrols.”

As a dedicated fixed-wing man, Du Plessis doesn’t quite get all the fuss about multi-rotors, although he does own one. He explains: “Fixed-wings can take me places multi-rotors can’t go. It’s more like a real flying experience, especially when passing through clouds. Multi-rotor drones are great for close-up stuff, but they have their limitations. For high-altitude surveillance, rescue searches and nature conservation applications, fixed-wings are the way to go.” A software developer by profession, Du Plessis enjoys the technical challenge of writing and modifying software to extract every last atom of performance from his drone.

On the other hand, Thomas, a professional film-maker, is obsessed with getting the right angle and capturing quality footage. Drones have made a huge impact on the film industry, he says, allowing film crews to operate in ways never before possible: “When using a chopper to shoot low-level wide-angle scenes, we refer to the space it’s operating in as the ‘dead man’s curve’. That’s because, if it gets into trouble, it doesn’t have enough airspace in which to recover, so it crashes. There have been a number of fatalities on film sets over the years as a result of helicopters operating outside their safe zones. Drones, on the other hand, give us complete creative freedom.”

Another game-changer has been the dramatic reduction in production costs. Says Thomas: “Hiring a chopper plus a stabilised Cineflex camera platform can cost R65 000-plus an hour. You can buy a ready-to-fly multi-rotor for about the safe money, and it will do virtually the same job. What used to be possible only in big-budget productions can now be done by anyone with a little training.” Professional camera gear is heavy stuff, but as Thomas points out, this is no longer an issue. “Guys are lifting up to 100 kg nowadays, which covers just about any camera that’s ever been made.”

Prinsloo, the man who started it all, simply enjoys the sensation of FPV flying. One of his favourite pastimes is to get some altitude at night and use the city lights to guide him through the black sky. An ardent nature-lover, he describes a particularly memorable flight during the flower season while visiting the West Coast: “While flying around and looking at the flowers, I noticed a small herd of zebra and decided to follow them. I ended up filming them wandering among the flowers with their foals… it was very special.” Another memorable, if less relaxing moment came when he found himself flying through dense fog with only his head-up display to tell him where to go.

Project Freedom kicked off after Thomas and Soobramoney met at a second-hand hobbyist fair. Both wanted to develop a machine specifically for FPV, and since they seemed to be getting along quite well, they decided to team up. Says Prinsloo: “I know how to fly and he’s got the engineering experience; that’s why it’s worked. The flying experience is what Freedom’s all about. If you want to film a bridge or go up to 800 metres, no problem. I flew out to the wrecked Seli 1 bulk carrier in Table Bay six times and ended up with some pretty unique footage. That’s the thing about FPV… it encourages you to go out and really explore.”

Soobramoney, the acknowledged techie of the team, came up with the idea of incorporating the circuit boards into the drone’s fuselage – an approach, as far as he knows, adopted by only one other company in the world. It’s here that his solid background in circuit board manufacturing came in handy.

“Fortunately, my company is always looking out for new tech, so it happily funded the entire project, including all the R&D. This was a huge help, as it does get expensive.” Soobramoney designed the circuits with adaptability in mind, making them capable of handling loads of up to 150 amps. The brushless, pan/tilt camera gimbal that comes packaged with each Freedom is all his work, too.

According to Soobramoney, much of the credit for Freedom’s success is due to the team’s diverse backgrounds, interests and flying styles. To date, they’ve flown three versions. “We made four or five each time so that all of us could have one. We then proceeded to thrash them to identify flaws; the feedback we accumulated was invaluable. For example, Willie loves pushing the boundaries, which is good – it forced us to adapt it to handle wind gusts of up to 35 knots.”

Although he has yet to add the finishing touches to the production version, Soobramoney is already thinking ahead. Ideas for a retractable landing gear and a ballistic parachute system are swimming through his head. Reaching behind his desk, he pulls out a distinctly battered Freedom drone and examines it with an expression of mild regret: “My poor craft… it’s a complete mess. That’s because I’m continually crashing and ploughing it into the ground to make sure everything works properly.”

Whatever it takes, guys. Whatever it takes.

For more information, visit:
● FPV-SA’s Facebook page at www.facebook.com/#!/fpvsa
www.sadrones.co.za (a site for the South African drone/UAV community)
www.steadidrone.com (Knysna-based supplier of drone kits and various ready-to-fly models)
www.multirotor.co.za (Johannesburg-based online store)
www.xtrememulticopters.co.za (excellent drones built by guru Greg Raymond)

 

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