This Machine-Vision Ekranoplan Might Just Follow You Home

April 29, 2022 by Dan Maloney 9 Comments

What is it that’s not quite either a plane or a boat, but has characteristics of both? There are probably a lot of things that fit that description, but the one that [Nick Rehm] is working on is known as an ekranoplan. Specifically, he’s looking to make the surface-skimming ground-effect vehicle operate autonomously.

If you think you’ve heard about ekranoplans around here before, you’d be right — we’ve covered a cool LIDAR-controlled model ekranoplan that [rctestflight] worked on about a year ago, and more recently, [ThinkFlight]’s attempts to make an autonomous ekranoplan that can follow behind a boat. The latter is where [Nick] enters the collaboration, and the featherweight foam ground-effect vehicle shown in the video below is his test platform.

After sorting out the basic airframe design and getting the LIDAR integrated, he turned his attention to the autonomous bit, which relies on a Raspberry Pi 4 running ROS and a camera with a wide-angle lens. The Pi uses machine vision algorithms to find an “AprilTag” fiducial marker in the scene, which gives the flight controller information about the relative orientation of the ekranoplan to the tag. [Nick] tested tag tracking using an electric longboard, and the model ekranoplan did an admirable job of not only managing the ground-effect, but also staying on target right behind him. And hats off to [Nick] for keeping all the balls in the air and not breaking his neck in the process.

We’re looking forward to seeing what [Nick] built here end up in [ThinkFlight]’s big ekranoplan build. Ground-effect vehicles like these are undeniably cool, and it seems like they’ve got the potential to solve some interesting transportation problems.

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Drone Filming Chile’s Urban Bike Race Takes Some Fancy Radio Gear

April 27, 2022 by Lewin Day 13 Comments

Drones have revolutionized the world of videography in perhaps the biggest way since the advent of digital hardware. They’re used to get shots that are impractical or entirely impossible to get by any other means. The [Dutch Drone Gods] specialize in such work. When it came to filming an urban mountain bike race in a dense Chilean city, they had to bust out some serious tricks.

The FPV video feed was grainy, but good enough to keep the pilot on track. The drone carried a separate second camera for capturing high-quality footage of the run.

Typically, running a drone chase cam behind a biker would require some good first-person flying skills and a quick drone. However, for the Red Bull Valparaiso Cerro Abajo urban downhill event, this alone would not be enough. The tight course winds down staircases between thick concrete walls and even through houses, presenting huge challenges to maintaining signal integrity. Without a clear video signal, the pilot can’t fly the drone without crashing.

To make this all possible, the team used a variety of techniques to help combat the uncooperative radio environment. Directional antennas were used to target different sections of the course. Additionally, a second drone was flown high above the course carrying a radio repeater, helping provide a better line-of-sight contact to the camera drone following the riders when the buildings would otherwise block the signal to the pilot.

Even with all this work, the signal was still scratchy and would cut out at some points. However, with a bit of blind faith when cutting through the worst areas, the [Dutch Drone Gods] and the [Red Bull] team were able to put together an amazing FPV drone shot shadowing [Tomas Slavik] on his run down the extremely difficult urban course.

Details on the precise hardware are scarce. However, it’s something that any experienced drone builder could probably whip up without too much trouble. The idea of using a drone-based repeater is particularly exciting, and something we’re sure could help out many pilots who find themselves operating in difficult urban environments.

We’ve seen plenty of great FPV stories over the years, from early experiments in the 1980s to fun DIY cockpit builds of today. Video after the break.

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Modular Anti-Drone Drone Sacrifices Itself For Self Defense

April 22, 2022 by Ryan Flowers 18 Comments

Part Racing Drone, Part RC Airplane, Part Rocket…all Menace. How else could you describe a quadcopter that shoots off at high speed and is designed for taking down other small quadcopters? The Interceptor Drone by [Aleksey] borrows elements from all of the aforementioned disciplines of flying things.

Built with standard racing drone parts, [Aleksey] assures that no prohibited parts are used in its construction. Instead, the Interceptor Drone relies on a very powerful motors and a light weight frame to keep the power to weight ratio in the “rocketing into the sky” category.

A close up shows the details: Detachable motors and rotors and the stowed net.

But what Interceptor Drone would be complete without a way to take its target out of the sky? This is where the biggest divergences begin. The motors are all oriented to point away from the center-line of the craft. Upon command, these motors actually detach from the frame, each spreading out and deploying the corner of a net that’s designed to entangle the rotors of the target, causing its battle with gravity to come to a grinding halt.

How does the Interceptor Drone survive the attack? Without its motors, the core of the quadcopter falls to the earth. Arresting the fall is a parachute much like those used in model rocketry. An audio beacon sounds the alarm to help somebody to find it — a move taken straight from the RC aircraft hobby.

There’s certainly a lot of room to discuss legalities in localities, but regardless of opinion about the craft’s intended use, the system looks very slick, and there are some great hacks baked right in. Don’t want to build a drone-killing-drone? Maybe all you need is a pumpkin and good (bad?) timing.

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Wireless Charging For Border Patrol Drones

March 17, 2022 by Al Williams 43 Comments

It makes sense to use drones to patrol borders or perimeters. But there’s a problem. Drones have to carry batteries or fuel and mostly have a short operating time. A new paper from the University of Houston proposes a solution by recharging drones in flight using a novel wireless charging mechanism. What’s the cost? Another paper explores the economics of the approach.

The system relies on electric lines running along a border wall feeding wireless power transfer devices that allow the drone to recharge in flight. This is akin, we think, to an electric train that takes power from the third rail except, in this case, the power rail is wireless. Also, the drone would still have batteries to enable it to go off the rail as needed.

The paper mentions that the source power could be from wind or solar, but that’s not necessarily important and it also requires a storage battery in the system that you could omit if using conventional power. In addition, you’d think batteries and solar panels might be targets for theft in remote areas.

The paper mentions that another alternative is to simply have charging towers along the wall where drones land to recharge. This is easier, we think, but it does put the drone out of full operation status while charging. On the other hand, cheap drones could work in shifts to cover an area, so it seems like that might be a better solution than charging while flying.

What do you think? How would you make a long-duration drone? Fuel cells? In-flight battery swapping from a refueling drone? Laser power? Maybe a magnetic battery swap system where the drone swoops over a charger to drop off and pick up a fresh battery? Let us know what you would try or — even better — what you have done.

We’ve seen a drone pit stop robot already. Refueling drones have been done, too. But it does seem like something better is possible.

Renaissance-Style Drone Would Make Da Vinci Proud Four Times Over

February 1, 2022 by Dan Maloney 7 Comments

For as much of a genius as Leonardo da Vinci obviously was, modern eyes looking upon his notebooks from the 1400s tend to see his designs as somewhat quaint. After all, his concept of a vehicle armored with wood would probably only have survived the archers and pikemen of a Renaissance battlefield, and his curious helicopter driven by an Archimedes screw would certainly never fly, right?

Don’t tell that to [Austin Prete] and his team from the University of Maryland, who’ve built a da Vinci-style quadcopter that actually flies. Called the “Crimson Spin”, the quad is based on a standard airframe and electronics. Details are sparse — the group just presented the work at a vertical flight conference — but it appears the usual plastic props are replaced with lightweight screws made from wire and some sort of transparent plastic membrane. Opposing pairs of screws have the opposite handedness, which gives the quad yaw control. There’s a video embedded in the link above that shows the quad being tested both indoors and out, and performing surprisingly well. We’d imagine that Crimson Spin might not do so well on a windy day, given the large wind cross-section those screws present, but the fact it got off the ground at all is cool enough. It kind of makes you wonder where we’d be today if da Vinci had access to BLDCs.

For as fanciful as da Vinci’s designs can be, we’ve seen a fair number of attempts to recreate them in modern materials. His cryptex is a perennial favorite for hackers, and his bizarre piano-esque “viola organista” has been attempted at least once.

Thanks to [Peter Ryseck] for this tip.

Radio Control Joby Aircraft Uses Six Tiltrotors To Fly

January 29, 2022 by Lewin Day 3 Comments

eVTOL (Electric Vertical Take-off and Landing) craft are some of the more exciting air vehicles being developed lately. They aim to combine the maneuverability and landing benefits of helicopters with the environmental benefits of electric drive, and are often touted as the only way air taxis could ever be practical. The aircraft from Joby Aviation are some of the most advanced in this space, and [Peter Ryseck] set about building a radio-controlled model that flies in the same way.

The design is inspired by the Joby eVTOL test vehicle.

The result is mighty complex, with six tilt rotors controlled via servos for the utmost in maneuverability. These allow the vehicle to take off vertically, while allowing the rotors to tilt horizontally for better efficiency in forward flight, as seen on the Bell-Boeing V-22 Osprey.

The build uses a 3D-printed chassis which made implementing all the tilt rotor mounts and mechanisms as straightforward as possible. A Teensy flight controller is responsible for controlling the craft, running the dRehmFlight VTOL firmware. The assembled craft only weighs 320 grams including battery; an impressive achievement given the extra motors and servos used relative to a regular quadcopter build.

With some tuning, hovering flight proved relatively easy to achieve. The inner four motors are used like a traditional quadcopter in this mode, constantly varying RPM to keep the craft stable. The outer two motors are then pivoted as needed for additional control authority.

In forward flight, pitch is controlled by adjusting the angle of the central four motors. Roll is achieved by tilting the rotors on either side of the plane’s central axis, and yaw control is provided by differential thrust. In the transitional period between modes, simple interpolation is used between both modes until transition is complete.

Outdoor flight testing showed the vehicle is readily capable of graceful forward flight much like a conventional fixed wing plane. In the hover mode, it just looks like any other multirotor. Overall, it’s a great demonstration of what it takes to build a successful tilt rotor craft.

We’ve seen tilt rotor UAVs before, and they’re as cool as they are complicated to build. Video after the break.

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Underwater Drone Films, Is In Film

January 22, 2022 by Al Williams 3 Comments

Having a drone that can follow you running or biking with a camera isn’t big news these days. But French firm Notilo Plus has an underwater drone that can follow and video an underwater diver. The Seasam has been around since 2019, but recently made an appearance in a French film, The Deep House about a couple exploring an underwater haunted house, as reported by New Atlas. You can see a video about the drone — and a trailer for the movie — in the videos below.

To follow a diver, the robot uses an acoustic signal from the user’s control unit to find the approximate location of the user. This works even in dark conditions. Once close enough, computer vision zeros in on the diver while a sonar system allows safe navigation.

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