System ID feature issues

Hi all you smart people.
Im new here, so sorry if Im breaking any unwritten (or written) rules.

I am working on a project where I want to make a model of a quad (approx 2kg, 45 cm wheelbase) in order to import it to a simulator. In order to identify the model, I thought the System ID feature looked promising and decided to give it a go - following the instructions of the documentation (and our brilliant Bill Geyer). Ive performed two flights, while sweeping both roll and pitch in order to gather data.

I used the following parameters:

SID axis : 10 and 11
SID_F_START_HZ : 0.05
SID_F_STOP_HZ : 3
SID_MAGNITUDE : 0.1
Fade in/Fade out: 5
SID_T_REC : 130

It took some tries in order to complete the flights, due to there being some drift - and I was controlling all inputs but the ones getting injected.

However, when I try to input the data into the Ardu Web Tool SysID - I dont seem to get any good match. Could someone please direct me into the correct approach in order to reach a better fit? Or maybe it is a good fit, and I am not able to tell. I do have the opportunity to perform the flights indoors - even though the flights did not have too much wind.

All help appreaciated.

Why are you not using ArduCopter 4.6.3?

Hi! This is mainly because it is a customer drone. Do you think this would improve the results of the test?

Hard to tell, I do not use 4.5.x for a looong time.

Your results look very bad, Because the I term is messing your measurements.

AMC explains how to do SID axis 10 correctly on step 42.

They are indeed bad.
Are you sure? I disabled the following parameters ( Identification of a Multicopter — Copter documentation ):

  • ATC_RAT_RLL_I
  • ATC_RAT_PIT_I
  • ATC_RAT_YAW_I
  • ATC_RATE_FF_ENAB

Yes, I know. I am one of the authors of that documentation.

But after writing that we found out that it is better to do some more changes.
Those are documented only in the AMC step 42. Feel free to do a PR to update the wiki documentation.

I see. Would it be possible to just get the parameters needed for 4.5? Or are the parameters which are not available on 4.5?

AMC will work with both 4.5 and 4.6 versions. The parameters are available on both versions and are the same.

Aaah, I see. I see the param-files 42,43,44 and 45 - which are the ones I will use. Are there any “best practice” for using them? I see that the axis on the files are all set to 0 etc. Other than that, they are ready to use or do I need to configure the software with all the information about my drone?

Also; thank you for your guidance.

It depends on your goals:

Do you want to correctly configure and tune your vehicle?
Then I suggest you follow

If you just don’t care about the quality of your tune: then do not use the software, do not lean it.