At first I fly my quadplane in FBWA mode,and then I slow down my plane and then change to Qhover mode, it acts well . I control the plane in Qhover mode until the plane stabe,without horizontal speed.At this moment I change to Qloiter mode,beyond my expecting,plane didn’t change to Qloiter stablly,the plane raise its head heavily,making strong noise and then loiter well.
I want to know why the translation is’t stable? Can the plane head don’t raise?
can you post a dataflash log file? It certainly isn’t a general problem, as I have switched from QHOVER to QLOITER a lot. The log may give me an indication as to why it is misbehaving. It could be as simple as needing a bit of tuning in the position or velocity controllers.
I don’t know how to find out the reason through the log analysising about this problem.it’s my great pleasure if you can show me.
I post the logs here download
Please let me know if you can’t download it .
it would be useful to have the dataflash log as well. Can you please look for it on the microSD card.
hi,tridge,have you downloaded my bin log?
sorry for the slow reply.
It looks like the code is working correctly, it is just being too agressive in bringing the speed from 1m/s down to zero when you enter QLOITER.
To fix this you can lower Q_WP_LOIT_MAXA from 250 down to 150, and lower Q_WP_LOIT_JERK from 1000 down to 250. That will make the transition a lot smoother.
I’ve also added more detailed velocity control logging for the next release which will make this sort of issue easier to diagnose.
hi,tridge,thanks for your reply.
Although I don’t know what the “Q_WP_LOIT_MAXA” and “Q_WP_LOIT_JERK” means, I try your para. The transition seems more smoother. But it seem like that the PID was affected after I adjusted the para. My plane become more wobbly than before.I think the transition may be unstable as before if I redo the PID tuning.Is it right?
Graph before I changed the para
Graph after I changed the para
download bin after I changed the para
Can you explain the meaning of the para?
Hi,tridge,I greatly need your help.My plane cann’t maintain the alt in auto mode.I have
reported the problem here http://discuss.ardupilot.org/t/altitude-fluctuating-about-10m-in-auto-mode/8775.
Hoping your reply.Thanks!