Bosch DOK-MOTOR-MCL Series, Project Planning Manual

Page: 180 / 196

is mainly in the frequency range from 400 to 800 Hz. It depends on the rigidi‐
ty 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 highest
attenuation takes effect on the rejection frequency. The bandwith defines the
frequency range at which the attenuation is less than –3 dB. A higher band‐
width leads to less attenuation of the rejection frequency!
Fig. 14-8: Amplitude response of the rejection filter in relation to the bandwidth,
qualitative
Bosch Rexroth AG DOK-MOTOR*-MCL********-PR05-EN-P 178/193
Rexroth IndraDyn L Ironless Linear Motors MCL
Commissioning, operation and maintenance