15. COMPENSATION FUNCTION
S : Single block stop point
Cutter center path
Fig15.11 (e) Point at which a Single–Block Stop Occurs
in the Normal Direction Control Mode
Before circular interpolation is started, the C–axis is rotated so that the
C–axis becomes normal to the arc at the start point. During circular
interpolation, the tool is controlled so that the C–axis is always
perpendicular to the tool path determined by circular interpolation.
Center of the arc
Tool center path
The tool is controlled so that the C–
is always normal to the tool path de-
termined by circular interpolation.
A rotation command is inserted
so that the C–axis becomes nor-
mal to the arc at the start point.
Fig15.11 (f) Normal direction control of the circular interpolation
During normal direction control, the C axis always rotates
through an angle less than 180 deg. I.e., it rotates in
whichever direction provides the shorter route.