Mitsubishi Electric MELFA CR750 Series User Manual page 278

13.4.11.2. Position data posture components
Position data of MELFA-BASIC IV consists of tip position (X, Y, Z) and tip posture elements (A, B, C)
This section describes the cases where [Use the posture elements of position data] is checked and not
checked.
Memo
(*1) The posture elements of position data
In case of the vertical 6-axis robot, the posture elements of position data are (A, B, C).
In case of the vertical 5-axis robot, the posture elements of position data are (A, B).
In case of the horizontal 4-axis robot, the posture element of position data is (C).
(1) [Use the posture elements of position data] is checked
Not just the robot tip position (X, Y, Z) but also the tip posture elements are used for position correction
calculation.
Precision of generated revision parameter improves if the tip posture elements are also re-taught correctly.
However, if the tip posture elements are not re-taught correctly, as shown in the diagrams below
(re-teaching positions P1 and P2), error occurs in position correction calculation, decreasing the precision of
the calculation result.
If posture elements are not re-taught accurately
Re-teaching
Original position
and posture position P1
(2) [Use the posture elements of position data] is not checked
Posture elements in the position data taught during re-teaching are not used for position correction
calculation.
If it is not necessary to match exactly the tip posture elements during re-teaching, clear the checkbox
[Use the posture elements of position data]. In such case, position correction calculation is performed using
only the tool tip position data (X, Y, Z), ignoring the error from posture deviation. This increases the
precision of location correction.
However, there are some restrictions. For details, see "Table 13-11 About Posture Elements of
Re-teaching Position Data".
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If posture elements are
re-taught accurately
Re-teaching Re-teaching
position P2 position P3
.
(*1)
Re-teaching position
Original position and posture
Position and posture before
re-teaching
Position and posture after
re-teaching
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