Showing posts with label uav. Show all posts
Showing posts with label uav. Show all posts

Sunday, May 26, 2013

Multiwii 2.2 Stick configuration - Mode 1

I was playing with my custom built quadrocopter based on Multiwii platform, but had trouble finding a comprehensive guide to stick configuration functions online. I stumbled upon Mr. Hamburger's awesome cheatsheet, but found out that for my Mode 1 stick configuration it was wrong. I have throttle and yaw on the right stick and pitch & roll on the left. I haven't tested all functions, but they should work.

Here's a modified version for anyone interested: Download multiwii 2.2 stick configuration cheat sheet for Mode 1 PDF.



If you want to make your own changes, I recommend downloading Hamburger's latest open office file, but here's my M$ office edited version also.

Sunday, March 15, 2009

Why should Model Aircraft be unstable? Meet the moment of inertia

Physics is not my strongest subject, but while playing around with a pencil in my hand, I started wondering what's wrong with the following picture of a traditional setup of an RC plane:


While this might be a good setup for a fast manually controlled "trick planes", the end result of concentrating all the weight on the center of the plane makes it more "unstable". Simply put if most of the mass of an object is located in it's center of gravity, it's easier to rotate than an object with weight concentrated on the outside edges. So especially for UAV and training models, I'd recommend a setup, where for example the batteries would be located at the wingtips rather than at the center:


This setup should allow for a more stable flight and make it easier to do automatic stabilisation. It also has the added bonus of not having to make wings as strong, as the lighter central body of an aircraft won't bend wings so much - there's a reason why big real aircraft have fuel tanks on the wings. This setup might be hard to modify on an existing model, but when designing a flying wing UAV - this is a must.

The article on Moment of Inertia in Wikipedia explains the physics behind rotating similar objects with different weight distributions. To get an easier example I recommend this site.

The plane images are originally from an article on Wikipedia, so use them if you want. And as always, if I'm wrong on this one - please correct me :)

Tuesday, March 10, 2009

Ubiquiti Networks Routerstation based OpenWrt UAV

I've had an arduino board and cheap ebay three axis accelerometers + GPS + compass sensors for a while, but I think that using just arduino is a bit limiting and good serial modems for telemetryare quite expensive.

I want something more scalable, and therefore have been thinking about the Routerstation platform. It's only about 50-60€ + postage, and it features 680Mhz MIPS 24K CPU, 64MB RAM, and 16MB Flash and most importantly Srrial and USB 2.0. Atheros mini-pci wlan-boards can be used for connectivity and are dirt cheap on ebay.

So if you have USB, you have basically everything to play around with. UMTS modems, webcams, USB-serial ports, gphoto2 usb interface to your digital camera etc.

Please share your thoughts and give other suggestions on embedded linux platforms.