Servers by jDrones

Vehicle out of control after few minutes

(Riccardo Benedetti) #1

Hi all, I am experiencing a strange issue with my Pixhawk (Arducopter 3.4.6) copter.
during the last 2 flights my quad went out of control after a couple of minutes of good flight. I can see Gyro and Acc health going down but I can’t figure out why. After that behaviour the copter become very instable and I managed to land in emergency braking 2 props and the gimbal support.

Does anybody has any idea?


2017-07-02 16-22-36.bin (1.3 MB)

(Javier Cerna) #2


Just from the log analyzer, there’s nothing wrong except the crash you mentioned and the motor pwm differences from the average.

Size (kb) 2806.158203125
No of lines 34544
Duration 0:01:47
Vehicletype ArduCopter
Firmware Version V3.4.6
Firmware Hash e707341b
Hardware Type
Free Mem 0
Skipped Lines 0
Test: Autotune = NA -
Test: Brownout = GOOD -
Test: Compass = GOOD - mag_field interference within limits (17.09%)

Test: Dupe Log Data = GOOD -
Test: Empty = GOOD -
Test: Event/Failsafe = FAIL - ERR found: CRASH
Test: GPS = GOOD -
Test: IMU Mismatch = GOOD - (Mismatch: 0.27, WARN: 0.75, FAIL: 1.50)
Test: Motor Balance = FAIL - Motor channel averages = [1548, 1458, 1422, 1387, 1377, 1622]
Average motor output = 1469
Difference between min and max motor averages = 245
Test: Parameters = GOOD -
Test: PM = NA -
Test: Pitch/Roll = NA -
Test: Thrust = NA -
Test: VCC = GOOD -

However, when I tried to check for any error from motors or ESC (by having a saturated signal value) I found that there’s something really weird with your motor outputs: you have signal from C1, C2, C3, C4, C6 and C8. I was expecting to see a signal from C5, but it’s always 0.

Moreover, C8 looks like a reflection of C6 with an offset.

Just in case, could you check your signals from the Pixhawk (without props) to discard a bad wiring or something related?



(Riccardo Benedetti) #3

Hi Javier, thanks for the help first of all.

I will check the wiring from the pixhawk to ESCs as soon as I get back from office this afternoon. Just a question, I only have 4 motors, is it normal to have 8 motor outputs enabled?

(Javier Cerna) #4

Hi Riccardo,

It’s weird since the log analyzer shows 6 PWM outputs. I have never used the main channels for anything else than motors, so I may be wrong. Are you using RC6 and RC8 for a servo or another actuator which needs a signal from the Pixhawk?

(Riccardo Benedetti) #5

I use RC6 for gimbal tilt control, RC8 is not used anyway. How can I disable it?