LibrePilot Forum

Users => Vehicles - MultiRotors => Topic started by: ceegeester on October 17, 2016, 08:13:34 am

Title: Motors not maintaining RPM
Post by: ceegeester on October 17, 2016, 08:13:34 am
Pretty much a newbie to MultiRotors but getting there slowly. Have a 250 quad with a cc3d FC and have managed to go through all of the LibrePilot set up successfully. ESCs seem to have all calibrated OK and TX is working fine. Problem I am getting is when I arm the quad and give it minimal throttle the motors seem to gradually increase RPM to something in excess of 50%. Props are off and I am not game to put them on until I can get the throttle working properly. Any ideas on what I have missed would be most appreciated.
Title: Re: Motors not maintaining RPM
Post by: f5soh on October 17, 2016, 10:45:31 am
Hi, welcome.

That a normal behavior.
Stabilization uses PID controller. The "I" term is integral, a small error is accumulated (can be a small angle diff if you run Attitude or simply Yaw)
The board try to compensate / correct the error without effect because no movement. The "I" term simply increases according to the error.
Title: Re: Motors not maintaining RPM
Post by: ceegeester on October 17, 2016, 11:26:14 am
Thanks for the reply. I think I understand what you are saying so are there any Stabilisation PID settings that I should set up to get my first flight going. In the flight mode section I have set Stab1 to Attitude, Attitude, Axis Lock, Manual. In the Basic Stabilisation page I have ticked the Use Basic configuration box and have it on Moderate setting. I have also ticked the Integral box to avoid the integral windup. Are there any other boxes that I should tick. Hope you can help.
Title: Re: Motors not maintaining RPM
Post by: f5soh on October 17, 2016, 11:34:26 am
All defaults are just fine for a first flight, at least should allow takeoff.

Later you can fine tune PID using easytune.
https://librepilot.atlassian.net/wiki/display/LPDOC/EasyTune