15 Nov 2006 cschur   » (Master)

Well, we have finished all the arena testing and evaluation of the PicBot III unit, for exploring the pros and cons of IR Proximity navigation. Now, we are working on the final report, to be shared when it is complete. There were a few surprises with the IR prox sensor array.

First surprise was how much larger the robot becomes when "non contact" IR prox sensors are used. In other words, the virtual size of the robot nearly triples for white walls, and only increases an inch for black obstacles! And to make matters worse, you dont even know what the reflectivity of your obstacle is, so are you a foot, or an inch away? This creates some amusing tunneling entrapment situations. You can get stuck in a confined area that looked dark when you went in, but is white when you turn around to escape - and thus you are quite trapped.

Another surprise was the reflectivity of obstacles in 940nm IR is quite unpredictable. Plants are pure white, so are my black socks! Black poster board is a neutral grey, and black IC foam is totally invisible. To help visualize this, we are adding to the write up an extensive set of images of household objects photographed in deep infrared so you can actually see what the robot will see when it moves about. Pretty cool, ay?



Latest blog entries     Older blog entries

Share this page