Siemens SINUMERIK 840D sl Function Manual page 412

Compensations (K3)
Friction compensation (quadrant error compensation)
Methods of friction compensation
One of two friction compensation methods can be selected on the SINUMERIK 840D
(MD32490 $MA_FRICT_COMP_MODE (friction compensation method)):
● Conventional friction compensation
With this type, the intensity of the compensation pulse can be set according to the
characteristic as a function of the acceleration. This characteristic must be determined and
parameterized during commissioning using the circularity test. The procedure for this is
relatively complicated and requires some experience.
● Quadrant error compensation with neural networks
To simplify commissioning, the compensation characteristic no longer has to be set manually
by the commissioning engineer but is determined automatically during a training phase and
then stored in the non-volatile user memory.
The neural network can reproduce a compensation curve of much better quality and
precision.
The function also allows simple automatic re-optimization directly at the machine.
Circularity test
The friction compensation function (both conventional and neural friction compensation) can
be commissioned most easily by means of a circularity test. This is done by following a
circular contour, measuring the actual position and representing the deviations from the
programmed radius (especially at the quadrant transition points) graphically. The
measurements are recorded using a "Trace" that is stored in the passive file system.
The circularity test is a "commissioning tool" function and can also be selected in the
Commissioning area of the HMI operator interface. For further information, refer to Section
"Circularity test".
412
(MD32490 = 1)
(option for SINUMERIK 840D)
(MD32490 = 2)
Function Manual, 03/2009, 6FC5397-1BP10-4BA0
Extended Functions