6.9.2 Torque command filter (P4-29) Set the filter time constant for gain attenuation upon approaching the resonance frequency. The cut-off frequency of the torque command filter can be calculated by using the formula below: Cut-off frequency (Hz) = 1/(2πЧparameter settingЧ0.00001) 6.9.3 Notch filter The EA190 servo driver has 4 notch filters, whose frequency, width and depth can be manually adjusted. The automatic mode is provided for the 3rd and 4th notch filter. Set P5-00 to 1, enter the motion command. When the resonance point affects the motor speed, the center frequency and notch depth parameters of the 3rd and the 4th notch filters can be automatically set.
If no resonance point is detected but vibration is present, the P05-01 value (automatic vibration detection accuracy and sensitivity) can be properly reduced in hope to find vibration points of smaller amplitudes. About the notching width and depth The notching center frequency when the notch filter width/depth is 0 and the ratio of frequency and bandwidth at the attenuation rate of -3dB are shown in the left table below. The notch filter depth represents input of the center frequency at full cut-off when the set value is 0, or the output/input ratio at full pass when the set value is 100. When represented in dB, numerical values in the right table below can be obtained.
59 Technical Manual for EA190 Series Servo Driver V100 Notching width Bandwidth/center frequency 0 0.1 1 0.59 2 0.71 3 0.84 4 1.0 5 1.19 6 1.41 7 1.68 8 2.0 9 2.38 10 2.83 11 3.36 Notching depth Output/input ratio dB 0 0 -∞ 1 0.01 -40 2 0.02 -34 3 0.03 -30.5 4 0.04 -28 5 0.05 -26 6 0.06 -24.4 7 0.07 -23.1 8 0.08 -21.9 9 0.09 -20.9 10 0.1 -20 15 0.15 -16.5