
B-63782EN/01 NC FUNCTIONS 5.FEED FUNCTION
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5.4 ACCELERATION/DECELERATION CONTROL
5.4.1 Automatic Acceleration/Deceleration Control After
Interpolation
Acceleration and deceleration is performed when starting and ending
movement, resulting in smooth start and stop. Automatic
acceleration/deceleration is also performed when feedrate changes, so
change in speed is also smoothly done. It is not necessary to take
acceleration/deceleration into consideration when programming.
The following automatic acceleration/deceleration after interpolation
can be performed for rapid traverse, cutting feed (including dry run), and
jog feed:
- Linear acceleration/deceleration
- Bell-shaped acceleration/deceleration
- Exponential acceleration/deceleration
For rapid traverse, acceleration/deceleration of the constant acceleration
type can be set, thus allowing efficient acceleration/deceleration at the
acceleration set for each axis. However, when linear interpolation-type
positioning is performed, the path may not match the specified line,
because acceleration/deceleration is performed for each axis.
- Linear acceleration/deceleration
With linear acceleration/deceleration, the time required for
acceleration/deceleration is the shortest, provided that the acceleration is
the same. Note, however, that if the acceleration is large (the time
constant is low), the stress and strain imposed on the machine system
may be considerable.
- Bell-shaped acceleration/deceleration
This type of acceleration/deceleration is named from its
acceleration/deceleration plots shaped like a bell. Even when a large
acceleration is set, smooth acceleration/deceleration in the start and end
of a change in speed can reduce a shock to the machine system.
- Exponential acceleration/deceleration
With exponential acceleration/deceleration, the acceleration/
deceleration delay is large. On large machines, however, the overshoot
can be reduced.