RPM Sensor Based Dynamic Notch Setup

  • Setup an RPM sensor.
  • Set INS_HNTCH_MODE = 2 or 5 to use an RPM sensor to set the harmonic notch frequency.
  • Set INS_HNTCH_ENABLE and/or INS_HNTC2_ENABLE = 1 to enable the harmonic notch
  • Set INS_HNTCH_REF and/or INS_HNTC2_REF = 1 to set the harmonic notch reference value to unscaled, unless the RPM sensor is reporting a fraction of the actual rotor speed. This might occur in a geared drive train setup. If the reported RPM is 1/3 the actual, for example, set this to 0.33.
  • Set INS_HNTCH_FREQ and/or INS_HNTC2_FREQ = below the hover frequency - you can easily determine this by performing a gentle hover and looking at the RPM sensor log data (RPM.rpm1)
  • Set INS_HNTCH_BW and/or INS_HNTC2_BW = half of INS_HNTCH_FREQ

Checking Harmonic Notch Effectiveness

After setting up the harmonic notch, the effect on the control signal data can be checked using the instructions for Post Configuration Confirmation Flight and Post-Flight Analysis in the throttle based setup.

While the log analysis required for the Throttle-based mode’s setup is not required for RPM based mode, the logging and analysis done for the Confirmation flight in that method can be done in order to confirm the noise elimination, if desired.