B–63522EN/02
15. ACCURACY COMPENSATION
FUNCTION
NC FUNCTION
225
These compensation functions all perform compensation at each
compensation point according to the machine position by dividing
machine strokes by the parameter–set compensation interval. Slope
compensation and straightness compensation use the compensation
interval and compensation point numbers of pitch error compensation but
use different compensation amounts that are prepared separately for the
slope compensation function and straightness compensation function.
In pitch error compensation, a compensation amount is set for each
compensation point in advance. At each compensation point, the
corresponding compensation amount is output.
With bi–directional pitch error compensation, the compensation amount
can be changed according to the axis move direction. In interpolation type
pitch error compensation, compensation pulses are output even between
compensation points, so smoother pitch error compensation is possible.
In slope compensation, a compensation amount is not set for each
compensation point; instead, compensation amounts are set for
representative four points (a, b, c, d) (compensation points for slope
compensation) selected from the compensation points for pitch error
compensation. At compensation points for pitch error compensation
located between the compensation points for slope compensation, the NC
calculates and outputs the compensation amount according to the
compensation amount for slope compensation. Slope compensation can
be applied when pitch errors have a constant slope.
b
a
c
d
15.6
ADIFFERENCE
AMONG PITCH
ERROR
COMPENSATION,
SLOPE
COMPENSATION,
AND STRAIGHTNESS
COMPENSATION