🚀 go-pugleaf

kilian@cray.com (Alan Kilian) writes:

>Well here's another project for you.
> [Describes project to measure acceleration of an arrow]

Well, I would take your approach of the "black and white" stripes on the
arrow and modify it a little bit...  If you had access to a laser scanner
assembly,  it would form an ideal high-resolution sampling device compared
to a phototransistor.  Actually, now that I think about it, a CCD element
might also do the job...  Even at top speeds of 200 ft/second, we're looking
at 38 KHz rate for 1/4" steps on the arrow with 4 points per region... Not
too bad, me thinks (for a CCD, that is)...  

The idea is to sample your image continuously at a high speed.  Then, the
only thing you need is the "start" trigger...  An edge transition in your
input...

Then, smooth the results post-collection.

-- 
Joseph Chiu, Dept. of Computer Science, Caltech.    josephc@coil.caltech.edu
1-57 California Institute of Technology, Pasadena, CA 91126. +1 818 449 5457 
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