Following the recent changes & refactoring of the motor libraries I've decided to measure my thrust curve to correctly find the value, instead of using the default - which by the way was very close to the value I got ( 0.6801).
Since measurement it is a time-consuming task and ( i believe ) the expo variable a very valuable parameter for FC, I would kindly submit a suggestion of implementing an autotune routine for that.
Also, esc / esc fw / battery and cable impedance could play a role on the results ( drone vs bench ) , so If we could rely on the measurement to be done in the uav itself would be the best of both words.
For that, the expo autotune could do something like:
Parameters: Height min/max for the test ( ex. from 15 to 100m )
descend phase floor: ( ex. 30m )
Max. curr drown ( same as battery? )
- check if mot_thst_hover ( and all related ) values are sane
- check battery
- lock the vertical position in loiter
- Climb to height_min and start the test:
test mot_thst_hover if it is really hovering, if so, define 7 point above to be tested, returning to its original position after every test.
Based on the results, extrapolate the climb rate to a descent rate and then test three points below hover, stopping the test if crossing the height-min floor or an user-defined floor for that could be an "safety value".
- Calculate the curve.
What do you think? Just an idea...