4.Vibration Analysis

A big part of setting up any model is checking that the vibrations are within the limits set by the APM: Copter developers.

The APM Log File Analyser can be used to understand the level of vibrations of your given UAV.

From version 2.2 of the APM Log File Analyser vibration can be reviewed using the Graph.

X & Y vibrations should be within the limits of + - 3, certainly when hovering. However, when flying they maybe slightly higher. Z vibration should be within the limits of -5 to -15, certainly when hovering. Again, when flying this maybe slightly higher.

Here is an example of a well tuned UAV.


Here is an example of excessive vibrations, and certainly something that requires attention. It is probably a bit unfair as this is during an auto tune where you would expect to see a fair bit of vibration coming through.


What I pick up about the above picture is that the vibrations are just as bad when there is no speed (i.e. hovering). At around marker 15000, this is where you would expect a tuned UAV to be at its best. Its high enough to be out of the ground wash, slow enough not to be receiving any vibration from turbulence, yet X and Y are way out of limits. Given this, I'm not sure I would be attempting an Auto Tune and probably why they crashed.

Lesson: Review vibrations and sort them before using Auto Tune :)