Siemens SINUMERIK 840D sl Programming Manual page 229

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.
Example: chaining of frames "concatenation with ADDFRAME".
Further information for the parameters for ADDFRAME(FRAME, STRING) see
/FB1/ Function Manual Basic Functions; Axes, Coordinate Systems, Frames (K2),
"FRAME Chaining".
Example
; parts program 1
;
DEF FRAME CORR_FRAME
;
;Setting measuring points
DEF REAL IDEAL_POINT[3,3] = SET(10.0,0.0,0.0, 0.0,10.0,0.0,
0.0,0.0,10.0)
DEF REAL MEAS_POINT[3,3] = SET
(10.1,0.2,-0.2, -0.2,10.2,0.1, -0.2,0.2, ,9); for test
DEF REAL FIT_QUALITY = 0
;
DEF REAL ROT_FRAME_LIMIT = 5 ;permits max. 5 degree rotation
;of the parts position
DEF REAL FIT_QUALITY_LIMIT = 3 ;permits max. 3 mm offset between
;the ideal and the measured triangle
DEF REAL SHOW_MCS_POS1[3]
DEF REAL SHOW_MCS_POS2[3]
DEF REAL SHOW_MCS_POS3[3]
;=======================================================
;
N100 G01 G90 F5000
N110 X0 Y0 Z0
;
Job planning
Programming Manual, 03/2006 Edition, 6FC5398-2BP10-1BA0
6.8 Frame calculation from three measuring points in space (MEAFRAME)
Frames
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