If you’ve ever tried to tune a PID system, you have probably encountered equal parts overwhelming math and black magic folk wisdom. Or maybe you just let the autotune take over. If you really want to get some good intuition for motion control algorithms, PID included, nothing beats a little hands-on experimentation.
To get you started, [Clovis] wrote in with his budget propeller-based PID demo platform (Portuguese, translated shockingly well here).
The basic setup is a potentiometer glued to a barbecue skewer with a mini-quadcopter motor and rotor on the end of it. A microcontroller reads the voltage and PWMs the propeller through a MOSFET. The goal is to have the pendulum hover stably in midair, controlled by whatever algorithms you can dream up on the controller. [Clovis]’ video demonstrates on-off and PID control of the fan. Adding a few more potentiometers (one for P, I, and D?) would make hands-on tweaking even more interactive.
In all, it’s a system that will only set you back a few bucks, but can teach you more than you’d learn in a month in college. Chances are good that you’re not going to have exactly the same brand of sardine can on hand that he did, but some improvisation is called for here.
If you don’t know why you’d like to master
open-loop closed-loop control algorithms, here’s one of the best advertisements that we’ve seen in a long time. But you don’t have to start out with hand-wound hundred-dollar motors, or precisely machined bits. As [Clovis] demonstrates, you can make do with a busted quadcopter and whatever you find in your kitchen.
Continue reading “Helicopter Pendulum is PID-licious”
Sometimes it’s not so much what you put together, it’s how you use it. The folks at Adafruit have put up a project on how to dress up your drone with ‘UFO lights’ just in time for Halloween. The project is a ring of RGB LEDs and a small microcontroller to give any quadcopter a spinning ‘tractor beam light’ effect. A 3D printed fixture handles attachment. If you’re using a DJI Phantom 4 like they are, you can power everything directly from the drone using a short USB cable, which means hardly any wiring work at all, and no permanent changes of any kind to the aircraft. Otherwise, you’re on your own for providing power but that’s probably well within the capabilities of anyone who messes with add-ons to hobby aircraft.
One thing this project demonstrates is how far things have come with regards to accessibility of parts and tools. A 3D printed fixture, an off-the-shelf RGB LED ring, and a drop-in software library for a small microcontroller makes this an afternoon project. The video (embedded below) also demonstrates how some unfamiliar lights and some darkness goes a long way toward turning the otherwise familiar Phantom quadcopter into a literal Unidentified Flying Object.
Continue reading “Easy UFO Lights on your Drone for Halloween”
Mount an umbrella to a drone and there you go, you have a flying umbrella. When [Alan Kwan] tried to do just that he found it wasn’t quite so simple. The result, once he’d worked it out though, is haunting. You get an uneasy feeling like you’re underwater watching jellyfish floating around you.
A grad student in MIT’s ACT (Art, Culture and Technology) program, [Alan’s] idea was to produce a synesthesia-like result in the viewer by having an inanimate object, an umbrella, appear as an animate object, a floating jellyfish. He first tried simply attaching the umbrella to an off-the-shelf drone. Since electronics occupy the center of the drone, the umbrella had to be mounted off-center. But he discovered that drones want most of their mass in the center and so that didn’t work. With the help of a classmate and input from peers and faculty he made a new drone with carbon fiber and metal parts that allowed him to mount the umbrella in the center. To further help with stability, the batteries were attached to the very bottom of the umbrella’s pole.
In addition to just making them fly, [Alan] also wanted the umbrella to gently undulate like a jellyfish, slowly opening and closing a little. He tried mounting servo motors inside the umbrella for the task. These turned out to be too heavy, but also unnecessary. Once flying outside at just the right propeller speed, the umbrellas undulated on their own. Watch them doing this in the video below accompanied by haunting music that makes you feel you’re watching a scene from Blade Runner.
Continue reading “Umbrella Drones — Jellyfish Of The Sky”
Hackaday was in Portland last weekend for the Open Hardware Summit. I did a brief recap earlier this week but this post has been on my mind the entire time. The night before the summit, OSH Park (the Purveyors of Perfect Purple PCBs which we all know and love) hosted a Bring-A-Hack at their headquarters. [Laen] knows how to throw a party — with a catered spread and open bar which all enjoyed. The place was packed with awesome hackers, and everyone had something amazing to show off.
In fact, there were far too many people showing off hardware for me to capture all in one evening. But join me after the jump for six or seven examples that really stuck out.
Continue reading “Look What Showed Up For Bring-A-Hack At OSH Park”
[Nicomedia] (a team of two) built a payload for their drone with two distinct purposes: to allow it to drop things like rose petals and to fire off fireworks. Honestly, while it is a cool idea, we are a little worried that dropping things from a height might not be a good idea (although rose petals are probably OK) and lighting off fireworks from a drone didn’t seem like a good idea at all. If you want to reproduce this, you probably need to make sure either of these things are legal in your part of the planet.
In the video below, you can see the effect. A servo tied to the drone’s controller opens the box to release the payload. In this case, the team didn’t have a spare channel so they used a separate controller, but if you had a spare channel on the flight controller, that would probably be better.
Continue reading “Party Drone Comes up Roses”
Flying ready-made quadcopters is fun. Eventually, though, most hackers get the urge to build their own. One of the most challenging parts is building a robust airframe. [Thomas Jarrett] has an interesting approach: he uses schedule 21 PVC pipe to build a sturdy airframe that is inexpensive and can house the craft’s electronics to boot. You can see a video of the sizeable aircraft, below.
The 1″ pipe is lightweight but sturdy and big enough to hold some circuitry. The rest is secured with Lexan. [Thomas] used off the shelf avionics, but it is obvious you could use the frame with your own choice of flight systems easily.
Perhaps the trickiest part is flattening the PVC for the motor mounts over a stove. The landing gear are also PVC, and formed in boiling water. Just be careful since hot PVC can give off nasty fumes (we aren’t experts on that, but it makes sense that it would be; you can watch a video about safety when heating PVC pipe). The total cost, including some prototyping parts, was under $300.
We’ve talked about building up drones in the past. If you don’t like PVC, you could always try old motherboards.
Continue reading “$12 Quadcopter Frame from PVC Pipe”
Building your own drone is a common enough pursuit among Hackaday readers. There are quite a few LEGO enthusiasts around, too. A company named Flybrix wants to marry those two pursuits and is offering a kit that allows you to build your drone out of LEGO bricks.
The company isn’t affiliated with LEGO. The kits look like they have some pretty common motors and control hardware. There are a few custom pieces, but the real key appears to be a LEGO compatible mount for the motors. You can see a video about the kit, below.
Continue reading “When LEGO Flies”