
B–63523EN–1/03
7. FEEDRATE CONTROL/ACCELERATION
AND DECELERATION CONTROL
813
When feed per minute is specified, this function reads several tens of
blocks ahead to perform acceleration/deceleration before interpolation,
that is, to apply acceleration/deceleration to the specified feedrate.
When acceleration/deceleration after interpolation is used, acceleration/
deceleration is applied to the interpolated data. Consequently, the inter-
polated data is changed by acceleration/deceleration. When acceleration/
deceleration before interpolation is used, however, acceleration/
deceleration is applied to the feedrate data before interpolation. Conse-
quently, the interpolated data is not changed by acceleration/deceleration.
Accordingly, interpolation data ensures that machining follows a
specified line or curve at all times, thus eliminating the machining profile
errors that result from delays in acceleration/deceleration.
Servo
control
Feedrate
command
Acceleration/
deceleration af-
ter interpolation
Interpola-
tion cal-
culation
Feedrate
calculation
Acceleration/
deceleration
before inter-
polation
Pulse
distribution
Linear,
bell–shaped
Linear interpolation,
circular interpolation, etc.
Linear, exponential
If a feedrate change along any axis is greater than the value set in a
parameter for the joint (corner) between two successive blocks, a feedrate
is calculated so that the difference in the feedrates does not exceed the
specified value. The feedrate is automatically reduced to this calculated
value at the corner.
Before this function can be used, specify parameter Nos. 8400 and 8401
for determining an acceleration for acceleration/deceleration before
interpolation.
7.1.14.1
Look–ahead
acceleration/deceleration
before interpolation