Discussions

I just put together a (gorgeous) Alien 560 quad last night with a Pixhawk. 

This morning I decided to fly a mapping mission, and the quad performed very well, but there were a few hiccups in the mission.

Even though the entire mission was at 50m, at several points in the flight, the quad ascended straight up more to 80m and then descended again and resumed the mission. Also, at the end of the mission, upon RTL the quad ascended up to 100m and then seemed to just stop there. Luckily it was close by, so I just took control and landed it.

Here is the mission I programmed:

 And here is the path that the quad actually took. You can clearly see the spikes. They seem to happen at waypoints 5 and 13, and upon RTL at the end of the mission.

Here is a graph of the altitude and the PWM value of channel 5 (controls flight mode). You can see that the spikes happened without any input from me. With the 3rd rise, I switched into RTL. You see the quad descend slightly, and then return back to the initial altitude. Then I switched to stabilize and landed it.

Any ideas on what might be going on here? I don't really care so much about the issues during the mission itself, but the failure to RTL (after the mission AND when I switched to RTL) was very concerning.

Thanks in advance!

2015-06-22 08-54-15.tlog

2015-06-22 08-54-15.tlog.kmz