PDA

View Full Version : Intuitive Dynamic Room Mapping



SilverVenom
06-03-2008, 05:40 PM
Hey everyone. :) I was just brainstorming some ideas for some low cost obstacle avoidance techniques - intended to be used in conjunction with path finding for my current robot project, and came up with the fallowing idea:

I'm sure everyone here has seen or at the very least heard of some tutorial covering how to create your own laser webcam range finder. With this method you can make a very accurate range finder with low cost parts. For those of you who haven't seen a setup similar to this, the arrangement consists of a webcam/CMOS camera + $5 laser pointer mounted at a right angle to the camera + some fancy software that does the trig in turn returning the distance to the object that the laser is focused on.

My idea entails mounting this setup onto pan/tilt turret, such as the one sold by trossen robotics here (http://www.trossenrobotics.com/store/p/5226-Pan-and-Tilt-Kit-no-servos-.aspx). Using some servo programming knowledge, one could potentially have the servos pan the senor array 360 degrees around + tilt for however tall the bot is. All this information could then be processed into a 3D array in software to give the bot a solid understanding of its surroundings, which could then be used for path finding or avoiding obstacles.

Some of the problems I can foresee with this device include:
1) How long would it take to make a full scan?
2) If the tilt servo is constantly switching directions making its vertical scans, I would imagine that could quickly kill the servo...? Any ideas on a better setup for tilt control?

Let me know what you think about the idea. I may very well build this in order to test its effectiveness, perhaps after a few more improvements upon the design, such as using a non visible light spectrum laser / filter for the camera?

Thanks in advance,
- Peter H.

Major Update: I just reasoned through and proved that as soon as you have data for one point inside of the FOV of the camera, you can then simply recalculate for every single pixel in view, as long as the picture hasn't changed. This would entirely eliminate the need for a tilt servo at all!!

Adrenalynn
06-03-2008, 08:46 PM
http://forums.trossenrobotics.com/showthread.php?t=1826&page=5

SilverVenom
06-04-2008, 07:41 PM
Exact type of discussion I am talking about. I have a few ideas about using a line laser in combination with a frenzel lens so that there would be no need for any servos..but I am still thinking on it. Thanks for the link Adrenalynn. :) I'll be sure to fallow the discussion going on there.