Society of Robots - Robot Forum

General Misc => Robot Videos => Topic started by: Admin on December 31, 2006, 08:48:12 PM

Title: UAV optical flow
Post by: Admin on December 31, 2006, 08:48:12 PM

for those who know what optical flow is, this is an autonomous UAV:

http://video.google.com/videoplay?docid=-1952814402978315740

optical flow measures pixel speed in the camera to determine velocity and altitude

Title: Re: UAV optical flow
Post by: JonHylands on January 01, 2007, 06:51:45 AM

That's very impressive...

I especially like how they used differentials in right and left optical flow to navigate in a canyon. I suspect that is how people do it when we're in a fast vehicle, especially in a car on a road.

- Jon

Title: Re: UAV optical flow
Post by: Admin on January 01, 2007, 10:08:28 PM

I just remembered where I saw that video before . . . it looked sooo familiar . . .

its a paper I read a few months ago, and i just uploaded it here:

Maximizing Miniature Aerial Vehicles (http://www.societyofrobots.com/robottheory/Maximizing_Miniature_Aerial_Vehicles.pdf) (2.4mb)
Griffiths, S.   Saunders, J.   Curtis, A.   Barber, B.   McLain, T.   Beard, R.   
Scientific Syst. Co., Inc., Woburn, MA, USA

I highly recommend everyone interested in aerial robots to read it (its much more educational than the video).

Title: Re: UAV optical flow
Post by: JonHylands on January 02, 2007, 04:55:19 AM

That is very cool stuff. They are using optical mouse sensors with camera lenses to do flow analysis. That basically gives them an 18x18 pixel camera that updates at 1500 fps !

Very cool stuff indeed  ;D

- Jon

Title: Re: UAV optical flow
Post by: JesseWelling on January 02, 2007, 05:50:37 AM

I've been trying to work in an encoder for my mini RC car robot (it's cramped) and I had thought about a mouse but I thought it would be too far off the ground (~2cm) but this idea gives me some new hope for decent odometry...After all I don't plan on going faster than 3m/s (almost 7mph....a good jog) .... not to derail the topic :-\