Friday, April 11, 2014

Learn to build an autonomous quadcopter

Quadcopters for all!


A while back, Widdikay and I took a class from Udacity on how to build a self-driving car.  It wasn't really about how to build a car, that is the easy part.  The class focused on the self-driving part.  Sure enough, in seven weeks we learned the basic principles required to build a self driving car that can navigate the streets around us.  In the process, not only did I learn about some really cool artificial intelligence techniques, I gained an appreciation for self-driving cars.  I'm pretty convinced at this point that the roads will be much safer when the self-driving cars dominate our highways.

Shelly - the Stanford/Audi self-driving car as it drove past me the other day
As our readers know we have an affinity for quadcopters around here.  So I was very excited to find that Technische Universit√§t M√ľnchen is teaching an online class on autonomous navigation of quad rotors.  I realize this isn't for everyone, but for those of you who are interested (and you know who you are) this could be really great.  And did I mention it's free?  This looks like a lot of fun.  Take a look at the video for some idea of what they will cover.


Class starts on May 6.  It will last for 8 weeks and is expected to take about 4 hours per week.  It is free to audit, so just do it!
More information can be found here, and the syllabus is available here.  

Visible sound


If asked what a sound looks like, some people immediately imagine a waveform.  This however is really a graphical representation of the compression and ratification of the air as the sound passes by a microphone.  It is not really what the sound looks like in space if we could see it.  I've seen people use something called cymatics to visualize sounds.  It is super cool (see the video below) and can map out where the nodes and antinodes of a sound are with vibrating particles.  The thing is that it is fairly static. It doesn't show sound propagating through the air.



However, the video below shows what sounds really looks like.  It uses a technique called Schlieren flow visualization to make minute changes in the density of the air visible.  By capturing minute changes in the density of the air and making them visible to your eye, we can actually see sound waves propagating.  Very cool!


Of course, the really cool version of this would be in 3D so that you could see sounds propagate out in all directions and bounce off of objects in the room.... Maybe some day.

Tuesday, April 1, 2014

The Expert


Have you ever been called on because you are an "expert?"  It is a great feeling.  At least for a little while. The feeling rarely lasts.  Sometimes you realize just how much of an expert your are... as in, no one else has a clue what they are talking about.  Or is it me?  No, I'm the expert.  I'm here because I'm supposed to know what I'm talking about, right?  Right?  Somebody?  Help!
The short film below captures the feeling perfectly.  I think I've attended this meeting... more than once.  Here's to the "experts."