Discussions

Hello All! 

I'm working on a large agricultural drone that I purchased during an overseas trip at an agricultural convention. The Quadcopter came with a DJI WooKong-m flight controller  so after a few flights, I immediately swapped it out with a pixhawk due to the DJI not being flexible for adding accessories laser altimeter and RTK GPS. 

Drone info: 

-full carbon fiber body

-12-15 Amp motors - All info is Chinese so unfortunately no more info that I could provide

-100A Platinum pro ESC's

-2 x 22.2 2600 Mah Lipo's

-Pixhawk FC - connected to power mudule #1

- 3DR GPS/MAG

-Jdrones long range radio's ( telemetry port) - connected to power module # 2

-X8R 2.4 ghz radio (rc)

-2 x power modules (http://www.targethobby.com/apm26-28-pixhawk-power-module-v10-output-bec-5v-3a-with-xt60-p-4162526.html)

(all test flights with RC controller & no payload))

I flew the quad after setting all of the recommended pixhawk parameters and calibrations. I tested some short take off and landings to make sure I could control the quad in Stabilize mode and all seemed ok (RC controller only). I added the Jdrones telemetry radios so I could have more info displayed during my next planned test flight. During this next test flight (stabilize mode)  the drone went into a crazy death wobble and flipped over during take off. Lucky the few second flight was at a low altitude so only the carbon fiber props were damaged and the top cover of the drone. Please note - During this crash I was only using the throttle control to take off. 

I'm a newbie when it comes to the pixhawk and analyzing the flight data but I noticed the compass info go way off during acceleration of the motors so possibly interference causing the problem?? If this is the case I'm not sure why the first few tests were o.k. This may be some helpful info but after the first test i attempted to re calibrate the compass and had issues with MP freezing during the calibration. Eventually I got it to work but compass # 2 had some large Z vale of -460 but from what I read it uses compass 1. After the crash its now giving a prearm error of inconsistent compasses. The pixhawk also wont always power up with battery power now but after multiple tries it will work. Any help would be appreciated. Thanks!

Auto log analyzer

Log File C:/Program Files (x86)/Mission Planner/logs/QUADROTOR/1/15 2016-08-27 8-25-08 AM.bin.log
Size (kb) 543.43359375
No of lines 7104
Duration 0:00:27
Vehicletype ArduCopter
Firmware Version V3.3.3
Firmware Hash acf2e10c
Hardware Type
Free Mem 0
Skipped Lines 0

Test: Autotune = NA -
Test: Balance/Twist = NA -
Test: Brownout = FAIL - Truncated Log? Ends while armed at altitude 3.20m
Test: Compass = FAIL - Large change in mag_field (70.30%)
Max mag field length (853.22) > recommended (550.00)

Test: Dupe Log Data = GOOD -
Test: Empty = GOOD -
Test: Event/Failsafe = GOOD -
Test: GPS = GOOD -
Test: IMU Mismatch = GOOD - (Mismatch: 0.10, WARN: 0.75, FAIL: 1.50)
Test: Parameters = GOOD -
Test: PM = NA -
Test: Pitch/Roll = NA -
Test: Thrust = NA -
Test: VCC = GOOD -

Hopefully i have provided enough info...

15 2016-08-27 8-25-08 AM.bin

15 2016-08-27 8-25-08 AM.bin.log