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geometry correction

Posted: Thu Oct 26, 2017 12:17 am
by Roucheux
using liteplacer with different height feeders, trays and board supports, i noticed non squareness over z height in both x and y .
Can you implement xz and yz squareness correction, like the xy one.

using the upper vision cam to get touch points over different z probing will give the correction to set.

as axes movement are synchronised, probing with squareness correction will give a correct pickup/place point even with different heights.

Re: geometry correction

Posted: Thu Oct 26, 2017 1:49 pm
by JuKu
This is much more complicated than that. First, we need to make sure that the camera is looking precisely down. A customer just this week gave me a great idea for that, so simple that I hit my forehead for not thinking it myself: Use a mirror. Ok, now when we know how to do that, the rest is doable: Design an adjustable camera holder to make this trim possible, and add to the software the understanding of pixel size vs z level and for items that need it, the z level information. This would make the different height items really usable.

Just getting the nozzle to go straight down is much easier: Calibrate first as it is done now. Then raise the target a known amount, and see how much correction is needed. Rest is 3d geometry. (Hmm... Yeah, actually this isn't that difficult. Thanks for the encouragement!)