Hello all, I hope someone can help me find the reason for this crash.
- Controller: Pixhawk LITE mini
- Motor: Turnigy Aerodrive 2836-1500kv
- ESC: HobbyKing 40A - opto
- No airspeed sensor
Upgraded the controller from V3.3.0 to V3.5.2.
Only problem I had during setup was with the accellerometer calibration - MissionPlanner never responded with “…Place vehicle level and press any key” (I saw a similar issue from another poster recently).The controller had previously been successfully calibrated with V3.3.0, so I skipped calibration, hoping the the old calibration would still be good. Everything else seem normal, so I had big hopes for the new FW.
So I went to the flying field to make a “firmware maiden”. Earlier with V3.3.0 the plane had been well tuned and flying good in all modes, including Auto mode with AutoTakeoff and waypoints. I also wanted to make a fresh AutoTune just in case the new FW with EKF would perform evenbetter with different PIDs.
AutoTakeoff was uneventful, as usual. I am a lousy thrower so this function is helping me a lot. Switched to AutoTune mode and performed both roll and pitch tuning. Bixler behaved like always - stable and easy to control even in some wind and gusts. Also tested flaps to see if programming a little bit down elevator in the TX was functioning.
All went well until I decided to land. During downwind leg, in FBWA mode, about to turn for landing, the plane lost som height. Knee jerk reaction made me throttle up and increase up elevator. Too late I realised the plane was not responding, and no time to switch to Manual mode the Bixler crashed behind some trees.
First I thought the elevator horn or link was broken, but looking at the log I don’t think that is the case (the horizontal stabiliser was ripped off in the crash, so could not be sure). I am not so good at analysing logs, so if someone would take a look at the enclosed screen grabs or maybe download the log file, I should be very grateful!
NOTE: I don’t blame the firmware for the crash as there are so many things I could have done wrong. The vibrations in flight (especially accZ) are horrible, not sure how much that comes from wind and AutoTune though. At the end, after the crash, the mode was switched to RTL (maybe by me in the confusion), as a result throttle went to 65%, and the accZ value looked almost normal - prop well balanced
Link to log at DropBox (hope it works, first time I try this): https://www.dropbox.com/s/hgr1sjscac1i3dd/2016-04-17%20Autotune%20-%20crash.bin?dl=0
Here is also a link to YouTube of the flight: https://youtu.be/nmlB9aedIWc
Log screen grabs:
- Crash 170416 - log 1 - RCIN_OUT.jpg
- Crash 170416 - log 2 - ATT.jpg
- Crash 170416 - log 3 - VIBE.jpg
- Crash 170416 - log 4 - IMU.jpg
- Crash 170416 - log 5 - PID.jpg