B--63003EN--1/02
7. FEEDRATE CONTROL/ACCELERATION
AND DECELERATION CONTROL
579
When the distance required to decelerate the tool from a specified feedrate
is less than the total travel of the tool in the blocks read in advance, the
feedrate is automatically clamped to a feedrate from which the tool can
be decelerated to a feedrate of zero.
Feedrate
Time
Clamp
feedrate
Totaltravelofthe
tool in the blocks
read in advance
Feedrate control
by look--ahead
bell--shaped ac-
celeration/decel-
eration before
interpolation
Specified
feedrate
When several blocks, each specifying a short travel, are specified in
succession, the following situation can occur:
The total travel of the tool in the blocks read in advance at the start of
acceleration is less than the distance required to decelerate the tool from
a specified feedrate, but the total travel of the tool in the blocks read in
advance at the end of acceleration is greater than the distance required to
decelerate the tool from a specified feedrate.
In such a case, the tool is accelerated once and clamped to the feedrate
obtained based on the total travel of the tool in the blocks read in advance.
Then, the tool is accelerated to a specified target feedrate.
D At the start of acceleration
Feedrate
Time
Clamp
feedrate
Totaltravelofthe
tool in the blocks
read in advance
Feedrate control by
look--ahead bell--
shaped acceleration/
deceleration before
interpolation
Specified feedrate
Feedrate clamping based
on th e total travel of the
tool in look--ahead
blocks