
B–63523EN–1/03
7. FEEDRATE CONTROL/ACCELERATION
AND DECELERATION CONTROL
902
Deceleration is started in a prior block so that the feedrate specified for
the target block is reached at the beginning of the block.
Deceleration extending over multiple blocks can be performed.
Feedrate
Deceleration start point
Feedrate control by look–ahead
bell–shaped acceleration/decel-
eration before interpolation
Specified feedrate
Deceleration start point
Time
When the total distance of blocks read in advance reaches the distance for
decelerating from the current feedrate, deceleration is started.
When look–ahead operation proceeds and the total distance of blocks
increases during deceleration, acceleration is started again.
If a series of blocks with a small amount of travel are specified, the
deceleration and acceleration may be alternated, which prevents the
feedrate from being constant. In this case, specify a lower feedrate.
When a single block is specified in look–ahead bell–shaped
acceleration/deceleration before interpolation, control is exercised as
follows:
(1)If acceleration or deceleration is performed when a single block is
specified
(a) When A + B is shorter than or equal to the remaining travel distance
of the block being executed when a single block is specified
Deceleration is performed and stopped so that the feedrate becomes
0 at the termination of the block being executed when a single block
is specified.
AB
Feedrate
Single block command
Time
A: Travel distance required until the target feedrate is reached with
the current acceleration/deceleration and acceleration/
deceleration terminates
D Deceleration
D Deceleration according
to the distance
D Single block in
look–ahead bell–shaped
acceleration/deceleration
control before
interpolation