I am a newbie. My d]Drone was in auto and undergoing a mission, changed to Stabilize mode automatically and crashed. Can anyone check the logs and see what really happen?
Cant download that file, like you link is wrong or something.
The usual problem is two fold:
- Radio transmitter has a non-centered throttle that usually sits at minimum (which suits planes)
- If the copter was armed in Stabilise or Acro modes, the copter will disarm after 2 seconds if throttle is at minimum
The pilot error is changing into Stabilise mode without realising where the throttle stick is.
In that case the copter does it’s best impression of a house brick
The fix:
Change the throttle stick to be spring-centered, and set:
PILOT_THR_BHV,7
Hi Shawn, Thank you for your reply
sorry for the link i’ve just uploaded to another website here: https://we.tl/t-18L8BYcZ7W
please try again with new link
OK, in this case the copter didnt disarm due to being armed it Stabilise mode (it wasnt) but throttle was at minimum the entire flight, and even though Loiter was selected soon after Stabilise mode the copter just did what it was told and descended to Earth with no intervention.
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can you tell me what is the cause of this issue on this flight and how to fix it ?, we’ve tested with many flights before this happened and this time cause serious damage on drone, so we want to know what’s the problem and how to prevent it. Thank you in advance
In fact it seems like there might have been a reboot but the copter tried to keep flying as it came back in Stabilise mode, then switched to Loiter, but the fact remains the throttle was at minimum the whole time.
I can only guess the reboot was triggered from the ground station, since there’s no power issues.
the drone was in auto mode doing the mission and then we lost radio and we already setup the RC Fail safe to “RTL”. However for some reason drone went into stabilize mode and then loiter mode. (By this time drone is already established link to telemetry). But again, there was no manual input from RC to turn to loiter or stabalise. Also in logs thats what we see. Please see in the image attached.
I know, I saw all that.
You might want to check your tlog to see if the reboot command came from the ground station.
And you still need to physically set the transmitter to have a spring-centered throttle.
EDIT:
It does look like the flight mode channel had a change via the RC Transmitter, but that could just be another symptom of the reboot. Because of the same effect, the Arm channel came back to high after a short time too, so I think the copter would have been able to fly if the throttle was up.
Thank you so much for your time and effort. we appriciate it!
I couldnt see a mavlink reboot command.
But there is a few instances of MAV_CMD_REQUEST_AUTOPILOT_CAPABILITIES (520) right at the time of the issue - I now think this has made it appear like a reboot, when it wasnt really.
This command has been replaced by an updated command since 2019, so I’m wondering what ground station you are using.
Do you think the RC Transmitter could have had a power glitch or reboot? That might explain all the channels dropping then coming back? But it didnt trigger an RC failsafe either, so that would be strange. The RC glitch was only 0.3 seconds.
here is additional info
- we use hm30 for telemetry and looks like we didn’t set the failsafe configuration on hm30
is there anyway to check if that’s the issue ?
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i don’t think we have power glitch or reboot, but we had this problem after a lost comunicaition between ground unit and air unit of HM30
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here is the setting and chart when the crash occur do you have and idea on why does it turn to stabilize and then loiter mode? nobody touched the remote control at that time
Either the TX or RX glitched, as all the channels changed briefly.
If that’s a 3 position switch set it to Stab, Stab, AltHold, AltHold, Loiter, Loiter.
But the throttle is still the big issue.
And test the failsafes (on the ground)
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siyi-hm30 can we somehow confirm that there is an issue with TX or RX glitched ? how can i confirm that it’s not because fail safe setting on HM30
It could have been an RC failsafe, but the RC failsafe timeout is 1 second.
RC_FS_TIMEOUT,1
so even if you cant find any reason for the RC glitch, fixing the throttle will at least save the copter and you’ll have plenty of opportunity to decide what to do.
The Flight Mode and Arm/Disarm channels were both affected at exactly the same time - maybe that can lead you to a clue with your transmitter programming or something…
EDIT:
If you do encounter an RC failsafe, my advice is to let the RTL complete, dont try to retake control.
Once the copter is on the ground safely, mess around with transmitters and receivers all you like to figure out what caused the failsafe.
- Mission in auto mode
- change to stabilize mode automatically
- then crashed
- From the log we have
QA:
- Does the log cover all those above stages, 1-2-3?
- Where is AUTO mode in the log???
- Why there is a Loiter mode? swtiched from stabilize mode automatically?/??
Hi thanks for your reply
in the image you can see the drone changed mode to auto mode by GCS cmd
and from next 2 image it looks like something triggered chanel 5 to change the drone mode to stabilize and turned back to loiter right away (based on PWM value) in the range table match with actual value from the log file
can this be the cause ?
- rc was set CH5 (mode) to STAB by default
- we change the mode to auto by GCS (didn’t touch CH5 value from the chart)
- when drone lost telemetry connection and regain connection it just listen to RC not GCS
that’s why the mode changed to STAB and Loiter
Auto mission failed - mid air change to stabilize here is the similar case when lost connection and the CH5 value dropped to 875
drone listen to RC (STAB) => drone listen to ground station ( turn to auto mode ) => drone lost and regain connection with RC then get STAB mode ?
so the question will be if we want to fix this problem what’s the best practice to implement it if
- most of the time we will not conenct drone to RC just use groun station to control does this approach remove this problem ?
or if there any advice would be appriciated !
Thanks in advance
I dont believe the telem link going up or down would affect the RC channels if they are separate devices. In your case the RC channels actually changed outputs. What components do you have?
For example most telem radios and RC receivers are completely separate devices - but a RFD900X and TXMOD can do both telem and RC, but if the link went down you’d definitely get a failsafe. Herelink is similar and I think Dragonlink is two-in one like that too.
It’s good practice to connect and have the Transmitter handy in case you need to take over. You could set Loiter as your default flight mode and switch position, along with fixing the centered throttle.