Setpoint speed filter time (0x2903): Indication for filtering in the setpoint path of the speed controller only for setpoint generation without trajectory calculation (profile generator)
Question:
In which applications is filtering in the setpoint path of the speed controller advantageous?
Answer:
Setpoint speed filter time (0x2903):
In practice, there are only a few indications for filtering in the setpoint path of the speed controller. For the vast majority of applications, it is recommended to leave the filter time 0x2903 set to 0s (factory setting). Especially for all applications with motion functions where the speed setpoints are generated via a trajectory calculation (profile generator).
Filtering the setpoint speed may be advantageous for speed applications where no trajectory calculation takes place in the setpoint planning, but the setpoint is generated from another source, e.g. from a speed sensor.
The speed controller should be set as tightly as possible with regard to the disturbance behaviour in order to be able to quickly compensate for dynamic disturbances. On the other hand, setpoint changes should not lead to high overshoot (command behaviour).
If necessary, the command behaviour can be optimised by a suitably adjusted filtering of the speed setpoint, keyword: elimination of zeros. In constellations without calculated trajectories, the filtering of the speed setpoint simply serves to give the speed controller the opportunity to adjust and thereby reduce the I component and thus reduce the overshoot of the actual value.
Background information:
The following book contains a description of the procedure for pre-filtering to smooth the reference variable in the speed control loop for very dynamic applications:
Taschenbuch d. Regelungstechnik Kap. 10.5.2 „Standardeinstellung des
Symmetrischen Optimums" von Lutz u. Wendt
