5-49
5-24 Instantaneous Speed Observer
Ope
rati
n
g Func
tions
5
Operating Procedure
1. Set the Inertia Ratio (Pn020).
Set the inertia ratio as accurately as possible.
Input the calculated inertia ratio if it has already been calculated when selecting a Servomotor.
If the inertia ratio is not known, perform normal mode autotuning and set the inertia ratio.
Use the Pn020 setting if the Inertia Ratio (Pn020) is obtained using realtime autotuning that can
be used in normal position control.
2. Adjust the gain for the position loop and speed loop.
Adjust the Position Loop Gain (Pn010), Speed Loop Gain (Pn011), Speed Loop Integration Time
Constant (Pn012), and Torque Command Filter Time Constant (Pn014).
Use normal mode autotuning and realtime autotuning if there are no problems in doing so.
3. Set the Instantaneous Speed Observer Setting (Pn027).
Set the Instantaneous Speed Observer Setting (Pn027) to 1. The speed detection method will
switch to the Instantaneous Speed Observer.
If the machine operating noise or vibration becomes louder, or the torque monitor waveform
fluctuates significantly, return the setting to 0 and make sure the inertia ratio and adjustment
parameters are correct.
If improvements are seen, such as a quieter operation, less vibration, or less fluctuation in the
torque monitor waveform, make fine adjustments in the Inertia Ratio (Pn020) to find the setting
that makes the least fluctuation while monitoring the position deviation waveform and the actual
speed waveform.
If changes are made to the Position Loop Gain (Pn010), Speed Loop Gain (Pn011), or Speed
Loop Integration Time Constant (Pn012), the optimum value for the Inertia Ratio (Pn020) may
have changed. Readjust the value in the Inertia Ratio (Pn020) so that the fluctuation will be
minimal.