Hello, I am interested in ardupilot systemid mod. But is there any document or information that shows exactly what the recovery roll/pitch/yaw point, which is the point where the chirp signal is applied, is and at which point of the control algorithm it is located?
All that documentation is available for multicopters. Traditional Heli does have some similarities, you can use that as a starting point.
@sefa_arslan As far as system ID is concerned, the mode operation and the points at which the inputs are made are the same for both multicopters and Helicopters. See this post for the diagrams that show these inputs.
I would point out that SID_axis= 1, 2 or 3 is made with RATE_FF_ENABLE true and SID_axis = 4, 5 or 6 is made with RATE_FF_ENABLE false.
The one thing of concern when using the System ID mode to generate flight dynamic models is that the response axes are very coupled with helicopters which causes inputs from the swept axis to be seen in the off-axes. So you may need to do some special post processing to identify a model with the data.
Hopefully this is helpful