Siemens SINUMERIK 840Di sl Commissioning Manual page 519

Measurement: Reference frequency response
The reference frequency response measurement determines the transmission ratio of the
position controller in the frequency range (active position measuring system).
The setpoint filters, control loop gain (K
parameterized such that resonance is avoided wherever possible over the entire frequency
range. In the case of dips in the frequency response, the setting of the feedforward control
balancing filters should be checked.
Measuring parameters
● Amplitude
● Bandwidth
● Averaging
● Settling time
● Offset
Manual
Commissioning Manual, 05/2008, 6FC5397–4CP10–4BA0
This parameter determines the magnitude of the test signal amplitude. It should be set to
the smallest possible value (e.g. 0.01 mm).
The bandwidth parameter is used to set the analyzed frequency range. The larger this
value, the finer the frequency resolution and the longer the measurement time. The
maximum value is specified by the position controller cycle (T
[Hz] = 1 / (2 * T
position controller
Example:
Position controller cycle: 2 ms
Bandwidth = 1 / (2 * 2*10
max
The accuracy of the measurement and measurement duration increase with this value. A
value of 20 is normally suitable.
This value represents the delay between recording of the measured data and injection of
the test setpoint and offset. A value of between 0.2 and 1 s is recommended. Do not set
too low a value for the settling times or the frequency response and phase diagrams will
be distorted.
The measurement requires a slight speed offset of a few motor revolutions per minute.
The offset must be set such that no speed zero crossings occur at the set amplitude.
14.4 Frequency response measurements
factor) and feedforward control must be
v
[sec])
) = 250 Hz
-3
Drive Optimization with HMI Advanced
): Bandwidth
position controller max
519