Archive for the ‘Robots’ Category

CONOPS and Autonomy Recommendations for VTOL MAVs Based on Observations of Hurricane Katrina UAV Operations

Saturday, March 15th, 2008

Preprint of my Autonomous Robots journal article based on our UAV work following Hurricane Katrina.

Title: CONOPS and Autonomy Recommendations for VTOL MAVs Based on Observations of Hurricane Katrina UAV Operations

PDF: UAVs at Hurricane Katrina journal preprint


This field study examines VTOL UAV operations conducted as part of an 8 day structural inspection task following Hurricane Katrina in 2005. From the observations of the 32 lights spread over 12 missions, four key findings are identified for CONOPS and the next level of artificial intelligence for rotary-wing UAVs operating in cluttered urban environments. These findings are 1) the minimum useful standoff distance from inspected structures is 2-5m, 2) omni-directional sensor capabilities are needed for obstacle avoidance, 3) GPS waypoint navigation is unnecessary, and 4) that these operations require three operators for one MAV. Based on the findings and other observations, a crewing organization and flight operations protocol for UAVs are proposed. Needed directions in research and development are also discussed. These recommendations are expected to contribute to the design of platforms, sensors, and artificial intelligence as well as facilitate the acceptance of UAVs into the workplace.

I’ll add this in once it gets published. It should be in Autonomous Robots eventually.

HOWTO: Convert Sun rasterfiles to an .avi movie

Friday, December 15th, 2006

For my research in optic flow I am working with the Yosemite sequence used in Barron, Fleet, and Beauchemin’s optic flow algorithm comparison “Performance of Optic Flow Techniques” (Link to Technical Report version). They were kind enough to publish the all of their code and the image sequences on their FTP site, but the images they provide are Sun rasterfiles, and the algorithms I need to work with all take .avi. Until I started work on this project I had never heard of rasterfiles, and indeed it is a pretty obscure file format.

After much search this is the best way I was able to come up with to convert a series of .ras rasterfiles to an avi.

Step 1: Convert the ras files to jpgs.

An excellent tool for this is XnView which is an image viewer/converter available for Windows/OS X/Linux/and many others… It reads more image formats than I knew existed, outputs to all the ones I would ever need (jpg, png, tiff, plus more…), and more importantly for this task, is capable of batch conversions.

Step 2: Convert the series of jpgs to an avi

Far and away the best way to do this is with mencoder / ffmpeg. Two links explain all you need about this step, the first is the documentation page from the MPlayer site (mencoder is the encoding and video creation sibling of MPlayer): Link to Mencoder doc and the second link is some additional comments and instructions from a grad student at MIT: Link 2 He also has some nifty things about embedding video in a pdf using LaTeX (bottom of the page). You can also do this step with pngs instead of jpgs if you prefer (XnView can output these as well). The install of mencoder I was using didn’t have the png libraries installed, so I didn’t bother with it, but they are available and there is plenty of documentation available to get this set up correctly.

Step 3: Enjoy your .avi

Here is the yosemite.avi I created for my project: Yosemite.avi optic flow video sequence

In as much as it’s in my power to do so I put that file in the public domain; please, use it. You’ll have to verify any additional requirements stipulated by the original FTP files.

And also a link to the optic flow library I was using for this project. It is part of the OpenCV library (Open source Computer Vision), and is pleasantly direct to work with and makes for very fast development times. OpenCV was also used heavily by the Stanford team, lead by Sebastian Thrun, which won the 2005 Grand Challenge. An excellent tutorial on using the pyramidal Lucas-Kande implementation in the library is written by David Stavens (a member of the Stanford team) and is available here: Link to Staven’s OpenCV OF tutorial

Overview of Requirements for Semi-Autonomous Flight in Miniature UAVs

Sunday, September 3rd, 2006

Here are the paper and the presentation for my first published paper, “Overview of Requirements for Semi-Autonomous Flight in Miniature UAVs”

Here is the paper (pdf link):

PDF of “Overview of Requirements for Semi-Autonomous Flight in Miniature UAVs”
and a zip file of the presentation with the included videos (45MB zip):

Zip of ppt and videos from my presentation at AUVSI 2006

and finally here is a pdf of the presentation (5MB pdf):

PDF of Semi-Autonomy Requirements (Presented at AUVSI 2006)

Also, here are the video segments individually:CNN clip about the Biloxi research , Flight obstacles short clip , Site Access short clip

Me and my Nerd Suit on CNN

Friday, December 9th, 2005

We were on CNN Thursday morning (Dec. 8th). View the piece here: CNN video segment (2 minutes and ~38M)

And yes, about 15 seconds in, thats me in my full up nerd suit with video eye-piece, clipped-on video camera, and back-pack with video-downlink antenna

(posted wicked late, as I’m emptying half-done posts while waiting for my 0245 LAS-HNL)

Pre-Deployment Katrina/Biloxi press

Tuesday, December 6th, 2005

Hey, neato, I’m in the news! Well, actually the robot helicopters that I work with were in the news, and I got a mention because I was the grad student sherpa, but I suppose you have to start somewhere.

Allegedly we were on Biloxi Sun-Herald on Saturday under sci/tech, and thats what I was looking for, but I couldn’t find the cnn article. I did find this article instead: Linux Electrons Article It looks like a reprint of this press release, but still, pretty neat.

And if I find the cnn article later, I’ll edit it in…. And a full post about the trip later (hopefully)

Turns out it was the Biloxi Sun-Herald that had the initial article….looks like their site is subscription only, so I don’t have a copy of the article…. maybe later.