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Turning, Milling, Nibbling
Function Manual, 11/2012, 6FC5397-1CP10-5BA0
69
Acceleration (B2)
4
4.1
Acceleration profiles
Abrupt acceleration changes
With the v/t-linear control of the axis velocity that is normally applied, the motion is controlled
such that the acceleration rate changes abruptly over time. With the discontinuous, stepped
acceleration, jerkfree starting and braking of the axes is not possible, but a timeoptimized
velocity/time profile can be implemented.
Acceleration with jerk limitation
The jerk is the change of acceleration over time. For jerk-limited acceleration the maximum
acceleration is not abrupt, but is specified by a ramp. Because of the softer acceleration
progression, the traverse time is longer than with abrupt acceleration for the same distance,
velocity and acceleration. This time loss can be compensated for by setting a higher
acceleration for the axes.
However, it has the following advantages:
●
Reduced wear to mechanical parts of the machine
●
Reduction of the excitation of highfrequency, difficult to control vibrations of the machine.
4.2
Jerk limitation on interpolator level
Selection and deselection of jerk-limited acceleration
MD32431 MAX_AX_JERK (maximum axis-specific jerk during path motion) can limit the
change in acceleration per machine axis individually. It only acts on the axes interpolated by
the path when SOFT is active. Jerk limitation is implemented entirely on the interpolator
level.
Acceleration with jerk limitation is activated by:
The program code SOFT in the part program. SOFT is modal and causes deselection of the
abrupt acceleration profile (BRISK). If SOFT is programmed in a block with path axes, the
previous block is ended with exact stop.
Acceleration with jerk limitation (SOFT) is deactivated by: