Hi Mates!
A dream of my childhood has finally come true. About a month ago I finished building my first drone. It’s a quadcopter based on DJI F450 frame with original Pixhawk (ArduCopter v3.2) flight controller + external GPS, with Open RLS 433Mhz (openLRSng v3.7.4) Rx and Tx, and Mobius action camera. I used HK ESCs 15-18A for hacker Style 20-26M motors, and Turnigy 9x as a controller.
So, I’m a newbie in RC, but I have a great desire to learn. I had just 3 flight session so far.
The first one completed in 10 seconds with a crash due to wrong programmed ESCs. Two of them were set Brake ON, another two - Brake OFF, what caused a flip right before landing. As a result 4 broken propellers and pulled out GPS mast.
The second flight session was rather successful. But I was scared by the first accident, so I tried to be careful as much as possible. I flew few meters above the ground. Noticed that pitch stick is inverted. Gave a try to different flight modes, but the copter wasn’t too responsive in modes other than Stabilize, + Simple, + Super Simple, so I switched them immediately off (AltHold, Loiter, etc).
The third session consisted of 2 flights.
After getting familiar with Loiter mode on the Internet, I decided to start a flight within it. Right after the arming, I pulled Throttle stick slowly up. The copter started taking off. After a while it seemed to be too high for me, so I started pulling Throttle stick slowly down to the very bottom position (and hold it in that position almost till the end). The drone didn’t listen to my commands. I started panicking - my hundreds of dollars are flying away from me, and I can do nothing. I pulled Land mode switch - no reaction at all. Then I noticed that it didn’t listen to the Throttle stick, but somehow reacts on pitch, roll and yaw controls. Probably the height was very high, and wind was really crazy at that altitude, so the copter wasn’t very responsive, but I managed to hold it more or less above me. After a minute of such crazy dances, I believe , it received my Throttle down command and turned motors off… fell down from about 25 meters… No serious damage though.
The problem here is not a fact of the crash, but uncontrolled climbing that caused a crash then.
You can see on the first graph (attached) that ThrottleIn was going down, while ThrottleOut kept on raising. When ThrOut followed ThrIn, it was rather smooth, then suddenly started fluctuating - that’s the moment of a kind of “glitch”.
Below you can a video from the copter, log file and a graph are attached to the post:
youtu.be/RxCGasv5uvc
Then I decided to fly again, but thousand times more careful. I thought that then I could manage to avoid such a wild behaviour again. I flew a dozen of seconds right above the ground and then BZzzzzzz… an it’s again in the clouds. I tried to follow the same strategy, but I wasn’t so lucky to “catch the signal”, so the best I managed to do is to direct it to the trees. One propeller and GPS mast were broken. Motors full of dirt.
Unfortunately, I don’t have video of that flight, but some a graph and logs are also attached.
I’ve spent a day analysing the log files, but couldn’t find anything specific.
Could you please take a look on what I wrote here and help me, if you see the reason of the issue? I’m really scared now to have any flight, until I’m 100% sure that the issue is resolved.
Looking forward to your assistance. Thanks in advance!
Logs:
2015-01-25 15-25-09 26.bin.log
2015-01-25 15-25-31 27.bin.log