LibrePilot Forum

Users => Vehicles - MultiRotors => Topic started by: modelvincent on April 07, 2016, 10:37:51 pm

Title: CC3D landing problem
Post by: modelvincent on April 07, 2016, 10:37:51 pm

Hi,

I'm discovering LibrePilot on my CC3D and I have a problem with landing...

I'm tuning the PID for the moment, but it's correct for flying, but unfortunately at landing, even with a smooth contact the quad immediately flip and fell on back, breaking a propeller at each time...

I've put some foam to absorb the shock but even with a very smooth landing on hard ground the quad immediately turn on his back...

Is there a way to stop the throttle at ground contact ? Or a way to prevent this?

Thanks in advance

Best regards,

Vincent

Title: Re: CC3D landing problem
Post by: f5soh on April 07, 2016, 10:46:16 pm

Hi Vincent,

Are you using AlwaysStabilized ?
Flying Attitude or Rate stabilization ?

If not, cut Throttle just before contact and it will not flip.
Check Stabilization > Basic > "Zero Integral when Throttle is low".

Laurent

Title: Re: CC3D landing problem
Post by: modelvincent on April 08, 2016, 01:42:40 pm

Thanks for your answer,

Yes sorry I forgot to precise that I'm flying in Attitude mode during landing (Pitch/roll on attitude, Yaw on rate).

And for the landing I keeping a little of throttle to have a proper landing, I don't like the landing like on aircraft carrier...

I will check If the Zero Integral box is checked or not.

Thanks

Vincent

Title: Re: CC3D landing problem
Post by: f5soh on April 08, 2016, 05:34:51 pm

Maybe you can test if issue is related to Accelerometers and see if the same effect appears landing in Rate mode.

Title: Re: CC3D landing problem
Post by: cato on April 15, 2016, 01:52:52 am

As you are writing that you are into PID tuning, this could be another issue. For example I had a much too high  Yaw I value, which did not disturb flight much (also not nice to fly), but gave the quad very ugly behavior on start and landing, a bit similar to what you are describing. If you can't find a different reason, it may be a good idea to post a screen shot of your current pid setting in the flight mode you are using for landing the quad.