Siemens SINUMERIK 840D sl Programming Manual page 289

<quality>
Note
Quality of the measurement
In order to map the measured coordinates onto the ideal coordinates using a rotation and a
translation, the triangle formed by the measured points must be congruent to the ideal
triangle. This is achieved by means of a compensation algorithm that minimizes the sum of
squared deviations needed to reshape the measured triangle into the ideal triangle.
Since the effective distortion can be used to judge the quality of the measurement,
MEAFRAME returns it as an additional variable.
Note
The frame created by MEAFRAME can be transformed by the ADDFRAME function into
another frame in the frame chain (see example "Chaining with ADDFRAME").
Examples
Example 1:
Part program 1:
Program code
...
DEF FRAME CORR_FRAME
Job Planning
Programming Manual, 03/2013, 6FC5398-2BP40-3BA1
5.6 Frame calculation from three measuring points in space (MEAFRAME)
: Variable with which information on the quality of the FRAME
calculation is returned
Type:
Value:
Coordinate transformations (frames)
VAR REAL
-1 The ideal points are almost on a straight line:
The frame could not be calculated. The
returned FRAME variable contains a neutral
frame.
-2 The measuring points are almost on a straight
line: The frame could not be calculated. The
returned FRAME variable contains a neutral
frame.
-4 The calculation of the rotation matrix failed for
a different reason.
≥ 0.0 Sum of distortions (distances between the
points), that are required to transform the
measured triangle into a triangle that is
congruent to the ideal triangle.
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