“DIRECT" mode

“DIRECT" mode (P-AXIS-00753) only uses direct measured values to dampen vibrations; the vibrations to be damped (P-AXIS-00751) must therefore be contained in the actual values.

The figure below shows the extension of the PPI cascade rule for “DIRECT" mode:

Ideally, frequencies to be damped are included in the speed value from v_Act2 and are recorded by a direct measuring system.

If no direct measuring system is installed, the actual values of the motor (v_Act1) can be used as an alternative, provided the vibration is visible in the actual speed of the motor encoder.

A total of up to 3 frequencies can be damped simultaneously. The measured frequency spectrum is reduced by a suitable band-pass filter to the appropriate frequency in each case. Optionally, the phase length of the filtered speed can be adapted by parameterising an all-pass filter.

Finally, the results of the individual filter paths are added.

After scaling the resulting speed, an additional additive speed (v_IPC) is added to the manipulated variable of the position controller (v_Cmd) This causes the motor to actively counteract the vibration in each case.