This tutorial video presents how to arrange Advanced Analysis with FFT in a mission planner.
Advanced Analysis with FFT¶
Refer to the Measuring Vibration with “Raw IMU Logging” page for instructions on collecting large amounts of IMU data and performing an FFT analysis to determine the frequencies with the most vibration.
IMU Dataflash Log message¶
For ancient versions of ArduPilot that do not include the Vibe message, the IMU values can be checked directly
Ensure the LOG_BITMASK parameter is set to include IMU data so accelerometer values are recorded to the data flash logs
Fly your copter in Stabilize mode and try to maintain a level hover (it doesn’t need to be perfectly stable or level)
Download the dataflash logs and after the download has completed, use the Mission Planner’s “Review a Log” button to open the latest file in the log directory (it’s last digit will be the Log number you downloaded so in the example above we downloaded Log #1 so the filename will end in 1.log)
When the Log Browser appears, scroll down until you find any IMU message. Click on the row’s AccX and push Graph this data Left button. Repeat for the AccY and AccZ columns to produce a graph like below.