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Support for log analysis


(alcala) #1

Hello from South of France
I just crashed my easyglider with pixhawk
Fuselage broken, rest is OK
The plane was in FWBA and suddendly went down (I tried a desparate RTL but no chance)
I tried to find the root cause without any success (I suspect a mechanical failure)

Can somebody do a check on the log file (attached)

Thanks in advance
Adolfo

[log crash easyglider]

https://drive.google.com/open?id=1jm8MEGJXREUuenIvVj51WcTr55Py9v2G


(Matthew ) #2

I don’t see a log file attached?


(alcala) #3

Thanks Matt

I put the file under link (hope it works)

Adolfo


(Hunt0r) #4

@adcam No, we can’t get the file yet. Your link is literally to “my Google Drive” so each of us gets routed to our own google drive. :laughing:

You need to right-click the file inside your Google Drive and use either “+Share” or “Get shareable link” (or something similar.)


(alcala) #5

I should be ok now

Adolfo


(Hunt0r) #6

I’m looking at your log, and see some things I haven’t seen before. Take a look at the messages in MSG.Message

You have two separate “events” that give strange messages. Mid-flight, from about 350sec till 370sec, the following messages are logged:
RCInput: decoding UNKNOWN
RCInput: decoding PX4IO_PPM
RCInput: decoding UNKNOWN
RCInput: decoding PX4IO_PPM
RCInput: decoding UNKNOWN
Throttle failsafe on
Failsafe. Short event on: type=1/reason=3
Flight mode = 1
RCInput: decoding PX4IO_PPM
Throttle failsafe off
Failsafe. Short event off: reason=3

Then, near the end of the flight (455sec to 475sec) a similar group is logged:
RCInput: decoding UNKNOWN
RCInput: decoding PX4IO_PPM
RCInput: decoding UNKNOWN
Throttle failsafe on
Failsafe. Short event on: type=1/reason=3
Flight mode = 1
RCInput: decoding PX4IO_PPM
Throttle failsafe off
Failsafe. Short event off: reason=3
RCInput: decoding UNKNOWN
RCInput: decoding PX4IO_PPM

I don’t know what causes these or if they have anything to do with the crash.

The plane appears to be in FBWA mode when the sharp terminal descent begins (t=481sec). During the descent it is switched to RTL mode, but that appears to have no effect. That suggests, as you suspected, a mechanical failure. I’m not sure if it helps to keep just looking around randomly… Do you have anything else we should look at, specifically?


(alcala) #7

Thanks hunt0r

also I found a switch to CIRCLE in the middle of the flight
This is strange :
I have only MANUAL, STABILIZE, FBWA & RTL (i am using Channel 8). When I look the log the Channel 8 is not moving but CIRCLE mode is popping -up

Also I was using FPV @ 1160 Mhz : this could interfere with my graupner (GR16 receiver)

i will do now ground tests with FPV close to GR16 receiver until I reproduce the strange messages

Interesting (despite the crash it is good to learn and improve)

Adolfo


(Andre-K) #8

What kind of output is your GR16 configured for ?
I have hundreds of GR16 hours using SUMO12 and SUMO8 , and have never seen decoding issues.


(Nathan E) #9

Ardupilot failsafes can make a switch to circle mode. I haven’t had time to look into your log, but CIRCLE mode is definitely possible.


(alcala) #10

To Andre-K I am using SUMO8

To Naterater

Yes you are right (I believe that it is a basic behaviour when RC signal is lost)

I am trying to reproduce the Failsafe by : FPV antenna closer to GR16, supply voltage noise…

Adolfo