When you think about all the forces that have to be balanced to keep a drone stable, it’s a wonder that the contraptions stay in the air at all. And when the only option for producing those forces is blowing around more or less air it’s natural to start looking for other, perhaps better ways to achieve flight control.
Taking a cue from the spacecraft industry, [Tom Stanton] decided to explore reaction wheels for controlling drones. The idea is simple – put a pair of relatively massive motorized wheels at right angles to each other on a drone, and use the forces they produce when they accelerate to control the drone’s pitch and roll. [Tom]’s video below gives a long and clear explanation of the physics involved before getting to the build, which results in an ungainly craft a little reminiscent of a lunar lander. The drone actually manages a few short, somewhat stable flights, but in general the reaction wheels don’t seem to be up to the task. [Tom] chalks this up to the fact that he’s using the current draw of each reaction wheel motor as a measure of its torque, which is not exactly correct for all situations. He suggests that motors with encoders might do a better job, but by the end of the video the little drone isn’t exactly in shape for continued experimentation.
Of course, dodgy reaction wheels don’t only cause problems with drones. They can also be a problem for spacecraft when the Sun gets fussy too.
Continue reading “Reaction Wheels Almost Control This Unusual Drone”
Some aspects of humanity affect all of us at some point in our lives. Whether it’s getting caught in the rain without an umbrella, getting a flat tire on the way to work, or upgrading a Linux package which somehow breaks the entire installation, some experiences are truly universal. Among these is pulling a few squares of toilet paper off the roll, only to have the entire roll unravel with an overly aggressive pull. It’s possible to employ a little technology so that none of us have to go through this hassle again, though.
[William Holden] and [Eric Strebel] have decided to tackle this problem with an innovative bearing of sorts that replaces a typical toilet paper holder. Embedded in the mechanism is a set of magnetic discs which provide a higher resistance than a normal roll holder would. Slowly pulling out squares of paper is possible, but like a non-Newtonian fluid becomes solid when a higher force is applied, the magnets will provide enough resistance when a higher speed tug is performed on the toilet paper. This causes the paper to tear rather than unspool the whole roll, and also allows the user to operate the toilet paper one-handed.
This is a great solution to a problem we’ve all faced but probably forgot about a minute after we experienced it. And, it also holds your cell phone to keep it from falling in the toilet! If you’d like to check out their Kickstarter, they are trying to raise money to bring the product to market. And, if you want to upgrade your toilet paper dispenser even further, there’s also an IoT device for it as well, of course.
Continue reading “Always Have A Square to Spare”
Classes are over at Cornell, and that means one thing: the students in [Bruce Land]’s microcontroller design course have submitted their final projects, many of which, like this flight control system for Google Earth’s flight simulator, find their way to the Hackaday tips line.
We actually got this tip several days ago, but since it revealed to us the previously unknown fact that Google Earth has a flight simulator mode, we’ve been somewhat distracted. Normally controlled by mouse and keyboard, [Sheila Balu] decided to give the sim a full set of flight controls to make it more realistic. The controls consist of a joystick with throttle, rudder pedals, and a small control panel with random switches. The whole thing is built of cardboard to keep costs down and to make the system easy to replicate. Interestingly, the joystick does not have the usual gimbals-mounted potentiometers to detect pitch and roll; rather, an IMU mounted on the top of the stick provides data on the stick position. All the controls talk to a PIC32, which sends the inputs over a serial cable to a Python script on the PC running Google Earth; the script simulates the mouse and keyboard commands needed to fly the sim. The video below shows [Sheila] taking an F-16 out for a spin, but despite being a pilot herself since age 16, she was curiously unable to land the fighter jet safely in a suburban neighborhood.
[Bruce]’s course looks like a blast, and [Sheila] clearly enjoyed it. We’re looking forward to the project dump, which last year included this billy-goat balancing Stewart platform, and a robotic ice cream topping applicator.
Continue reading “Microcontroller and IMU Team Up for Simple Flight Sim Controls”
Beware, arachnophobes, the robots are coming for you!
What else would you be expected to think if you watched a hexapod robot display its best Transformers impression by turning into a wheel and pushing itself in your direction? The BionicWheelBot — developed by [Festo] — should rightly remind you of the cartwheeling Flic-Flac spider, the main inspiration for the robot. Of course, Star Wars fans might justifiably see a Droideka.
The BionicWheelBot can — almost — seamlessly transition between crawling around on six legs, to literally rolling away. To do so, its three pairs of legs sequentially fold up into a shape befitting its namesake and then pauses for a moment — almost for dramatic effect — before the real fun begins.
Continue reading “It’s a Spider! It’s a Droideka! It’s Both!”