On Sat, 08 Aug 2015, Peter C. Wallace wrote: > > > > I think the trick the Resolute encoder uses is this: the image is captured > > in > > a perhaps sub microsecond flash of the LED, and then the "image" can be > > shifted out of the sensor at a leisurely rate. The specifications sort of > > suggests this (very fast capture (ns) time, but only multi KHz maximum > > update > > rate) > > > > Peter Wallace > > Mesa Electronics > > > > They may in fact use a laser for illumination as AFAIK you can get higher > peak > power with a pulsed laser than a LED. These are in the $30 region for 75W peak > 40 ns pulse width, not much vibration or motion blur in 40 ns :-) >
the problem is not the vibration in the 40ns but that the recorded encoder image is more or less a random position within the vibration range of the device + vibration of the laser - I was thinking about compensations like done with satelite images where multiple pictures are taken and then the signals are compensated by filtering out szintilation effects If the actual sampling is in the multi kHz range only then that would be well in the modes that such systems can have and one - worst case - would have the full vibration in the positional information. Just wonder if there are any detection algorithms that look into such issues. Naively one could do a fft on the position data under the assumption that motion should be constant/known-trajectory and that could reveale such vibration/aliasing induced errors. > http://www.osram-os.com/osram_os/en/products/product-catalog/laser-diodes/high-power-laser-diodes/pulsed-laser-diodes/hybrid-pulsed-laser-diodes/index.jsp > > ( thank you Harold Edgerton ) > thx! hofrat ------------------------------------------------------------------------------ _______________________________________________ Emc-developers mailing list Emc-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-developers
