B2: Acceleration
4.2 Functions
Basic Functions
Function Manual, 09/2011, 6FC5397-0BP40-2BA0
245
Bandstop filter with additional amplitude response increase/decrease at high frequencies
In this case, the numerator and denominator natural frequencies are set to different values. The numerator
natural frequency determines the blocking frequency.
By selecting a lower/higher denominator natural frequency than the numerator natural frequency, you can
increase/decrease the amplitude response at high frequencies. An amplitude response increase at high
frequencies can be justified in most cases, as the controlled system generally possesses a lowpass
characteristic itself, i.e., the amplitude response drops at high frequencies anyway.
Supplementary conditions
If too high a numerator natural frequency is selected, the filter is disabled. In this case the limiting frequency f
Zmax
depends on the position-control cycle:
The limitation is enabled for specific axes using machine data:
MD32400 $MA_AX_JERK_ENABLE (axial jerk limitation)
and set with time specifications for the smoothing filter using machine data:
MD32410 $MA_AX_JERK_TIME (time constants for the axial return filter)
.
With SW 5.1 and higher, it is also possible to control the jerk limitation in the position controller with a new filter
based on a smoothing method that incurs few contour errors:
Modus 2 requires a bit more computation time, but with the same smoothing effect, it results in lower contour
errors or, with the same accuracy, in a smoother contour with smoother movements. Mode 2 is recommended.
Mode 1 is the default mode in SW 1 to SW 4.4 for compatibility reasons.
For more information about how the jerk filter available with SW 5.1 and higher works (balancing filter for
improving the position setpoints of the position controller), please refer to:
References:
/FB1/ Manual of Functions, Basic Functions; Velocities, Setpoint/Actual-Value Systems, Regulatory Control (G2),
Chapter: "Control Optimization"
Mode 3
There are 2 parameterization options for the bandstop filter:
MD32402 AX_JERK_MODE = 1
; 2nd-order filter (default)
corresponds to SW 1 to SW 4.4
MD32402 AX_JERK_MODE = 2
; Sliding mean value generation
(New jerk filter with SW 5.1 and higher).
MD32402 AX_JERK_MODE = 3
; Bandstop filter with SW 6.3 and higher
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