2D Laser Scanning problem

[@mi]

Hello,

I made Labview design for the scanning application in raster pattern.

So, VI is intended to design to scan the sample in raster patter in applied voltage range,so if I apply -1 min to +1 max it scans that particular area in the applied voltage range.

I am using mirrors and they are configured to rotate 1degree when I apply 1V.

So, now in place of straight line in scanning I need parabolic curve lines to scan the sample and for that scanning parameter for the X mirrror will be the same, when Y mirror ends one line of scanning, but changes will be made for the Y axis mirror to rotate in a such way so that it can able to scan with the pattern of parabolic curve.

so , if some one can help for the same problem then it would be nice.

[wiebe@CARYA]

You need:

1) A conversion from X to hor.angle nd Y to vert.angle

2) A routine to produce the parabolic curve in XY space.

1) is a matter of hor.angle=tan(X/distance) and vert.angle=tan(Y/distance)

2) is a matter of looping over X and then calculating the Y with Y=a*X^2+b*X + c

All basic maths I think, but you'll have to write it out.

[GerdW]

Hi mi,

apply a different mathematical formula.

Use a formula to produce your "parabolic" movement - and not the linear ramp you are using now!

(It seems this is a pure mathematical problem, so I suggest to read a book on math.)

[wiebe@CARYA]

Of course it gets (much) more difficult if the steps on the parabolic curve need to be the same length.

But indeed, math, not LabVIEW...

[Bob_Schor]

Wow -- you are trying to get your laser to generate what we called "Smiley"s.  We had a ceiling-mounted Laser/Galvo system facing a curved screen.  Because of the geometry, when the beam wasn't earth-horizontal (and since it was ceiling-mounted, this was essentially "all the time"), the beam's path was parabolic.  We "worked out the math" to correct for this (somewhere I have the equations), then my Doubting Student actually stepped the Laser through known positions, measured them, then wrote a routine to "solve the equations backward", i.e. he mapped "known Laser" to "observed Spot location", then did a backwards interpolation to go from "desired Spot location" to "best estimate of Laser Position".  Our answers largely agreed -- I think we went with his "empirical" solution as it didn't need my assumption of a "perfect cylinder" (ours was made of cloth attached to a curved frame -- I think I took into account the offset between Laser Rotation Axes and the center of the Cylinder, but empirically, it doesn't matter, of course).

Bob Schor

[JÞB]

Bend the mirror