Loading the Compensation Table
Next we need to somehow acquire high precision distance measurements (via interferometer, etc.) to the surface at each of the X-Y locations in the compensation area, and store the X and Y offset positions.
Once you've obtained these positions, they will need to be loaded into our previously configured compensation table (See Determining Required Compensator Table Size). Continuing with our original example let's assume that our measurements are as defined by the following table below (taken from the comp.c sample application):
Interpreting compensator table above:
To compensate a Z (vertical) axis for X-Y surface irregularities, first define the X-Y area to be compensated (Xmin to Xmax, Ymin to Ymax).
Then define the spacing of the measuring points (delta) for the X and Y axes to determine the compensation table size.
For the X-Y table diagram below we have:
To load the above compensation table, execute the following code:
Once the compensation positions are loaded, the compensation will be applied to the Z-axis' position feedback loop every servo cycle.
NOTE: No more interpolated compensation of the Z-axis will occur outside of the defined compensation range. Therefore, the compensation of the Z-axis will remain fixed outside of this range.
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