January 2012 6.16 The Control Loop 811
6.16.3 Nominal position value filter
To attain a high machining velocity while maintaining a high surface quality, the
workpiece contour can be adapted to the machine dynamics by means of a
nominal position value filter.
Four types of low-pass filters are available for limiting the bandwidth of the
dynamics of nominal position and speed values.
Average (mean-value filter)
HSC filter (not available on lathes)
• HSC finishing filter
• HSC roughing filter
Advanced HSC filter (not available on lathes)
Triangle filter
Mean-value and triangle filter
The mean-value and triangle filters are low-pass filters that always smooth a
contour towards the inside at changes in direction. They can be used when a
very high surface quality is required, or when a high machining speed is
required and larger tolerances are permitted.
HEIDENHAIN recommends: Do not use the mean-value filter. This filter
provides a reduced edge steepness and was originally developed for internal
tests. Prefer the triangle filter.
HSC and advanced HSC filter (not available on lathes)
The speed advantage of both HSC filters is especially large for circular
contours. However, you must consider slight overshoots at corners and
curvature transitions that are within the given tolerances
(MP_pathTolerance).
HEIDENHAIN recommends: Prefer the HSC filter when a high accuracy is
required, and use the advanced HSC filter when you need a high surface
quality. The advanced HSC filter has a more even effect on the speed and any
possible overshoots.
Selection criteria
for the nominal
position value
filters
The settings for the nominal position value filters mainly depend on the
emphasis of the requirements for machining the workpiece. Speed and
accuracy, in connection with clean and smooth surfaces, are the decisive
criteria.
At the same time, the oscillation and resonance tendencies of the machining
system (the machine tool) are to be considered, and taken into account in the
settings for the nominal position value filters. The following recommendations
can be made for the settings:
To Next Page
Loading...
Need help?
General
