Technical Manual for EA350 Analog Pulse Type Servo Driver V101 6.9 Suppression of mechanical resonance When the mechanical rigidity is low, resonance resulted from shaft twisting and belt extension/contraction may produce vibration or noise; the gain setting may not be raised. In this case, a notch filter can be used to suppress points of resonance, so that a higher gain can be set or vibration can be reduced. 6.9.1 Block diagram of EA350 resonance suppression function 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: Cutoff frequency (Hz) = 2π Ч setting value of parameter Ч 0.00001 P4-03 6.9.3 Notch filter ➢ The EA350 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. 69