Bosch rexroth MBT, Руководство пользователя

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Filtering mechanical resonance vi‐
brations
Digital drives from Rexroth are able to provide a narrow-band suppression of
vibrations that are produced due to the power train between motor and me‐
chanical axis system. This results in increased drive dynamics with good sta‐
bility.
The mechanical system is excited to vibrate mechanically due to the position
and/or velocity return within the closed control loop. This behavior, known as
"Two-mass vibrational system", is mainly in the frequency range from 400 to
800 Hz. It depends on the rigidity of the mechanical system and the spatial
expansion of the system.
In most cases, this "Two-mass vibrational system" has a clear resonant fre‐
quency that can be selectively suppressed by a rejection filter installed in the
drive.
When the mechanical resonant frequency is suppressed, the dynamic prop‐
erties of the velocity control loop and of the position control loop may, under
certain circumstances, be improved as compared with closed-loop operation
without rejection filter.
This leads to an increased profile accuracy and shorter cycle times for posi‐
tioning processes at a sufficient distance to the stability limit.
Rejection frequency and bandwidth of the filter can be selected. The rejection
frequency is the frequency with the highest attenuation. The bandwidth de‐
fines the frequency range in which the attenuation is less than -3 dB. A higher
bandwidth leads to less attenuation of the rejection frequency!
Cutoff freqency f
cut
0
-3
Attenuation in dB Frequency f Bandwidth
Fig. 13-5: Amplitude response of the rejection filter in relation to the bandwidth,
qualitative
13.9 Deactivation
In case of malfunctions, maintenance measures or to deactivate the motors,
proceed as follows:
1. Comply with the instructions in the machine documentation.
2. Use the machine-side control commands to decelerate the drive to a
controlled standstill.
3. Switch off the power and control voltage of the controller.
4. Switch off the main switch of the machine and deactivate external sys‐
tems according to the instructions of the manufacturer.
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Commissioning, operation and maintenance
MBT High Synchronous Torque Motors
Bosch Rexroth AG R911298798_Edition 08