YASKAWA E-S Series Product Manual

Contents

8.8 Manual Tuning8.8.1 Tuning the Servo Gains8-358 Tuning Torque Reference FilterAs shown in the following diagram, the torque reference filter contains a first order lag filter andnotch filters arranged in series, and each filter operates independently.The notch filters can be enabled and disabled with the Pn408 = n.X and Pn408 =n.X. Torque Reference FilterIf you suspect that machine vibration is being caused by the Servo Drive, try adjusting thetorque reference filter time constant. This may stop the vibration. The lower the value, the bet-ter the control response characteristic will be, but there may be a limit depending on themachine conditions. Notch FiltersThe notch filter can eliminate specific frequency elements generated by the vibration of sourcessuch as resonance of the shaft of a ball screw.The notch filter puts a notch in the gain curve at the specific vibration frequency (called thenotch frequency). The frequency components near the notch frequency can be reduced orremoved with a notch filter.Notch filters are set with three parameters for the notch filter frequency, notch filter Q value,and notch filter depth. This section describes the notch filter Q value and notch filter depth.• Notch filter Q ValueThe setting of the notch filter Q value determines the width of the frequencies that are filteredfor the notch filter frequency. The width of the notch changes with the notch filter Q value. Thelarger the notch filter Q value is, the steeper the notch is and the narrower the width of frequen-cies that are filtered is.The notch filter frequency characteristics for different notch filter Q values are shown below.Note: The above notch filter frequency characteristics are based on calculated values and may be different fromactual characteristics.Pn401First Stage First Torque Reference Filter Time ConstantSetting Range Setting Unit Default Setting When Enabled Classification0 to 65,535 0.01 ms 100 Immediately TuningFirst stagefirst torquereferencefilter:Pn401Torque referencebefore filterFirst order lag filter Notch filterFirst stagenotchfilter:Pn409Pn40APn40BTorque-RelatedFunction SelectionsPn408Second stagenotchfilterPn40CPn40DPn40ENotch filterTorque referenceafter filter0-5-10-20-15Q = 0.7Q = 1.0Attenuation [dB]Q = 0.5Frequency [Hz]