Siemens SINUMERIK 840D sl Function Manual page 414

K3: Compensation
5.6 Friction compensation (quadrant error compensation)
Starting value
A relatively low injection amplitude plus a time constant of a few position controller cycles
should be entered as the start value when measuring commences.
Example:
MD32520 $MA_FRICT_COMP_CONST_MAX[n] = 10 (mm/min)
MD32540 $FRICT_COMP_TIME[n] = 0.008 (8 ms)
The effect of changing the parameters must be checked using the measured and plotted
circles.
Mean value calculation
If it is not possible to determine a common compensation time constant for the varying radii
and velocities, then the average of the calculated time constants must be worked out.
Good friction compensation setting
When the friction compensation function is well set, quadrant transitions are no longer
noticeable.
Figure 5-15
414
Quadrant transitions with correctly set friction compensation
Function Manual, 09/2009, 6FC5397-1BP20-0BA0
Extended Functions