Avian-Inspired Drones: How Studying Birds Of Prey Brings More Efficient Drones Closer

January 15, 2025 by Maya Posch 8 Comments

The EPFL LisRaptor with adjustable wings and tail.

Throughout evolution, the concept of powered flight has evolved and refined itself multiple times across both dinosaurs (birds), mammals (bats) and insects. So why is it that our human-made flying machines are so unlike them? The field of nature-inspired flying drones is a lively one, but one that is filled with challenges. In a recent video on the Ziroth YouTube channel, [Ryan Inis] takes a look at these efforts, in particular those of EPFL, whose recent RAVEN drone we had a look at recently already.

Along with RAVEN, there is also another project (LisRaptor) based on the Northern Goshawk, a bird of prey seen in both Europe and North-America. While RAVEN mostly focused on the near-vertical take-off that smaller birds are capable of, this project studies the interactions between the bird’s wings and tail, and how these enable rapid changes to the bird’s flight trajectory and velocity, while maintaining efficiency.

The video provides a good overview of this project. Where the LisRaptor differs from the animal is in having a rudder and a propeller, but the former should ideally not be necessary. Obviously the kinematics behind controlled flight are not at all easy, and the researchers spent a lot of time running through configurations aided by machine learning to achieve the ideal – and most efficient – wing and tail configuration. As these prototypes progress, they may one day lead to drones that are hard to differentiate from birds and bats.

Continue reading “Avian-Inspired Drones: How Studying Birds Of Prey Brings More Efficient Drones Closer” →

FPV Flying In Mixed Reality Is Easier Than You’d Think

January 3, 2025 by Tom Nardi 12 Comments

Flying a first-person view (FPV) remote controlled aircraft with goggles is an immersive experience that makes you feel as if you’re really sitting in the cockpit of the plane or quadcopter. Unfortunately, while your wearing the goggles, you’re also completely blind to the world around you. That’s why you’re supposed to have a spotter nearby to keep watch on the local meatspace while you’re looping through the air.

But what if you could have the best of both worlds? What if your goggles not only allowed you to see the video stream from your craft’s FPV camera, but you could also see the world around you. That’s precisely the idea behind mixed reality goggles such as Apple Vision Pro and Meta’s Quest, you just need to put all the pieces together. In a recent video [Hoarder Sam] shows you exactly how to pull it off, and we have to say, the results look quite compelling.

Continue reading “FPV Flying In Mixed Reality Is Easier Than You’d Think” →

DIYFPV: A New Home For Drone Builders

January 2, 2025 by Tom Nardi 30 Comments

If you’re looking to get into flying first-person view (FPV) remote controlled aircraft, there’s an incredible amount of information available online. Seriously, it’s ridiculous. In fact, between the different forums and the countless YouTube videos out there, it can be difficult to sort through the noise and actually find the information you need.

What if there was one location where FPV folks could look up hardware, compare notes, and maybe even meet up for the occasional flight? That’s the idea behind the recently launched DIYFPV. In its current state the website is a cross between a social media platform, a hardware database, and a tech support forum.

Being able to look up parts to see who has them in stock and for what price is certainly handy, and is likely to become a very valuable resource, especially as users start filling the database with first-hand reviews. There’s no shortage of social media platforms where you can post and chat about FPV, but pairing that with a dedicated tech support section has promise. Especially if the solutions it produces start getting scrapped by show up in search engines.

But the part of DIYFPV that has us the most interested is the interactive builder tool. As explained in the announcement video below, once this feature goes live, it will allow users to pick parts from the database and virtually wire them together. Parts are represented by high-quality illustrations that accurately represent connectors and solder pads, so you won’t be left guessing where you’re supposed to connect what. Schematics can be shared with others to help with troubleshooting or if you want to get feedback.

The potential here is immense. Imagine a function to estimate the mass of the currently selected electronics, or a simulation of how much current it will draw during flight. It’s not clear how far DIYFPV plans on taking this feature, but we’re eager to find out.

Continue reading “DIYFPV: A New Home For Drone Builders” →

Flying Drones That Can Walk And Jump Into The Air: An Idea With Legs?

December 10, 2024 by Maya Posch 13 Comments

When we look at how everyone’s favorite flying dinosaurs get around, we can see that although they use their wings a lot too, their legs are at least as important. Even waddling or hopping about somewhat ungainly on legs is more energy efficient than short flights, and taking off from the ground is helped by jumping into the air with a powerful leap from one’s legs. Based on this reasoning, a team of researchers set out to give flying drones their own bird-inspired legs, with their findings published in Nature (preprint on ArXiv).

The prototype RAVEN (Robotic Avian-inspired Vehicle for multiple ENvironments) drone is capable of hopping, walking, jumping onto an obstacle and jumping for take-off. This allows the drone to get into the optimal position for take-off and store energy in its legs to give it a boost when it takes to the skies. As it turned out, having passive & flexible toes here was essential for stability when waddling around, while jumping tests showed that the RAVEN’s legs provided well over 90% of the required take-off speed.

During take-off experiments the drone was able to jump to an altitude of about 0.4 meters, which allows it to clear ground-based obstacles and makes any kind of ‘runway’ unnecessary. Much like with our avian dinosaur friends the laws of physics dictate that there are strong scaling limits, which is why a raven can use this technique, but a swan or similar still requires a bit of runway instead of jumping elegantly into the air for near-vertical take-off. For smaller flying drones this approach would however absolutely seem to have legs.

Continue reading “Flying Drones That Can Walk And Jump Into The Air: An Idea With Legs?” →

Trying To Shatter The World’s Fastest RC Car Record

December 10, 2024 by Maya Posch 18 Comments

The RC car is controlled via an FPV setup. (Credit: Luke Bell, YouTube)

Fresh off a world record for the fastest quadcopter, [Luke Bell] decided to try his luck with something more own to earth, namely trying to tackle the world record for the fastest RC car, with the current record set at 360 km/h. Starting off with a first attempt in what will be a video series, the obvious approach seems to be to get some really powerful electric motors, a streamlined body and a disused runway to send said RC car hurtling along towards that golden medal. Of course, if it was that easy, others would have done it already.

With the quadcopter record of nearly 500 km/h which we covered previously, the challenge was in a way easier, as other than air resistance and accidental lithobraking there are no worries about ground texture, tire wear or boundary layer aerodynamics. In comparison, the RC car has to contend with all of these, with the runway’s rough tarmac surface being just one of the issues, along with making sure that the wheels would hold up to the required rotation speed. For the wheels you got options like foam, hard rubber, etc., all with their own advantages and disadvantages, mostly in terms of grip and reliability.

So far speeds of over 200 km/h are easy enough to do, with foam wheels being the preferred option. To push the RC car to 300 km/h and beyond, a lot more experimentation and trial runs will have to be performed. Pending are changes to the aerodynamic design with features also commonly seen in F1 race cars such as downforce spoilers, diffusers and other tricks which should prevent the RC car from (briefly) becoming an RC airplane.

Continue reading “Trying To Shatter The World’s Fastest RC Car Record” →

Small Feathers, Big Effects: Reducing Stall Speeds With Strips Of Plastic

December 2, 2024 by Danie Conradie 18 Comments

Birds have long been our inspiration for flight, and researchers at Princeton University have found a new trick in their arsenal: covert feathers. These small feathers on top of birds’ wings lay flat during normal flight but flare up in turbulence during landing. By attaching flexible plastic strips – “covert flaps” – to the top of a wing, the team has demonstrated impressive gains in aircraft performance at low speeds.

Wind tunnel tests and RC aircraft trials revealed a fascinating two-part mechanism. The front flaps interact with the turbulent shear layer, keeping it close to the wing surface, while the rear flap create a “pressure dam” that prevents high-pressure air from moving forward. The result? Up to 15% increase in lift and 13% reduction in drag at low speeds. Unfortunately the main body of the paper is behind a paywall, but video and abstract is still fascinating.

This innovation could be particularly valuable during takeoff and landing – phases where even a brief stall could spell disaster. The concept shares similarities with leading-edge slats found on STOL aircraft and fighter jets, which help maintain control at high angles of attack. Imitating feathers on aircraft wings can have some interesting applications, like improving control redundancy and efficiency.

Continue reading “Small Feathers, Big Effects: Reducing Stall Speeds With Strips Of Plastic” →

Experimental Drone Flies Like A Bird

November 25, 2024 by Danie Conradie 11 Comments

Most RC planes follow a simple control scheme: elevators for pitch, rudder for yaw, and ailerons for roll. This one-to-one mapping keeps things straightforward, and fewer actuators means less weight. But nature has other ideas. Birds achieve flight control through complex, coordinated movements where different body parts can affect multiple degrees of freedom simultaneously. Now, researchers at EPFL have brought this biological approach to robotics with the LisEagle, a drone featuring morphing wings and tail that demonstrate remarkable stability.

All the control surfaces and actuators — All the actuators!

The LisEagle packs seven different actuation methods alongside its nose-mounted motor. Three of these control the bird-like wingtips and spreading tail, while the remaining actuators handle more conventional controls: independently twisting wing bases (similar to ailerons) and a tail assembly that combines elevator and rudder functions in its vertical stabilizer.

Testing took place in controlled indoor conditions, with the maintaining position in front of an open wind tunnel. Optical position tracking provided closed-loop feedback and power was provided via a tether to minimize weight. A PID flight controller orchestrated all seven actuators in concert, achieving impressive stability even when faced with induced turbulence or being poked with a stick. In a demonstration of redundancy, the researchers deliberately disabled the twisting wing mechanisms, and the aircraft maintained control using just its wingtips and tail.

The team went further, employing Bayesian optimization to find the most efficient actuator combinations. This revealed potential energy savings of up to 11%, with optimal configurations varying based on airspeed as lift requirements changed.

While research into the flight mechanisms of bees, bats and birds might not immediately translate to practical applications, it deepens our understanding of flight control principles. Don’t be surprised if morphing wings become a more common sight in future aircraft designs.

Continue reading “Experimental Drone Flies Like A Bird” →