Go Home headed in wrong direction

[Traveler]

Anyone had a Go Home head 180 from home?

Happened to me. I had some bystanders asking questions about the bird, so without hesitation I went up and flew a few simple patterns, then upon showing how the Go Home was supposed to work, it headed away from home. Seeing the error I canceled and flew it back manually.

See attached pictures showing the home point, the Go Home command and the bird on a path 180 from home.

After this I landed, changed batteries and tested it again, but this time it worked as expected.

Odd...

 

[Meta4]

Anyone had a Go Home head 180 from home?

That sounds unusual and hard to explain.
The solution to the mystery is likely to be shown in the flight data though.
Go to https://www.phantomhelp.com/LogViewer/Upload/
Follow the instructions to upload your flight record.
You can post a link to the report it provides if you need help working it out.

 

[Traveler]

That sounds unusual and hard to explain.
The solution to the mystery is likely to be shown in the flight data though.
Go to https://www.phantomhelp.com/LogViewer/Upload/
Follow the instructions to upload your flight record.
You can post a link to the report it provides if you need help working it out.

Thanks Meta,
It was very odd and definitely a first.

I uploaded as requested.


BTW, I don't have the experience you have at this data analysis, but I note that after the Go Home started, it was showing that it was getting further from the home point, until I canceled the RTH and took manual control.


Tim

 

[Traveler]

Sorry,
forgot the link
DJI Flight Log Viewer - PhantomHelp.com

 

[Meta4]

Sorry, forgot the link
DJI Flight Log Viewer - PhantomHelp.com

That is an odd one.
The data confirms your explanation.
RTH initiated at 13:03.8 and with no input on the sticks the Phantom moved further away at around 20 mph until you cancelled and resumed control at 13:24.3
I also noted that the Phantom was climbing for part of the time, ascending 50 ft from 13:18 until you cancelled RTH - again, there was no joystick input to explain this.

The homepoint did not change during the flight.
I'm really scratching to find any explanation here and the direction of travel is a puzzle.
The climbing makes me wonder if the sun was upsetting the obstacle avoidance - was the Phantom heading towards a low, bright sun during RTH?

If I was you I'd do a trial RTH from 100 ft out to see if it was a weird one-off incident.

 

[Traveler]

That is an odd one.

Meta,

Thank you for validating my statement. Left to itself, this would have surely been one of those classified as a flyaway, not good.

The sun was 90 to 120 degrees to the right of the nose of the craft, so it would be closer to a side sensor vs the front sensor. I don't think it was a factor.

I will try to duplicate the events, to include a short period of drifting in ATTI, switching back to P-mode, then initiating RTH.

I hope we can determine the cause, I wouldn't want to see this happen to someone else.

Thank you for looking into it. Please let me know if you see or think of anything else that would help with this incident.

Tim

 

[Traveler]

That is an odd one.

Meta,

I have been giving additional thought to what could have influenced this event and although nothing conclusive comes to mind, I have a couple of thoughts to run past you.

First:
Like many, I updated to the 1.04 FW, but after reading concerns about this FW's reported bugs, I downgrade both the AC and the RC to the prior working version. I don't see this in itself a problem, but I had also updated the app and that was not downgraded. I don't even know if that is possible to do. Is it possible that the newer app is not so backward compatible with the my now 1.03 FW.

Second:
You may have noticed that time on this flight started at 11 minutes 46 seconds vs something in the neighborhood of 0 minutes. This is because this flight was actually interrupted by the bystanders I spoke of in my original post. I was flying and noticed that they needed some assistance with a toy drone, so I landed the AC, left it powered up in the ready, and after a short time on the ground, lifted off to show them how a DJI product operated in comparison to their toy. Could this idle (props not running) time have been sufficient to cause any excess heating of a critical component, i.e., IMU?

I know I reaching here, but something has to be the cause. I can't say I never land and takeoff again, like a touch and go from my fixed wing days, but I have never left it sitting on the ground for that long before. It was probably between 3 to 5 minutes on the ground. As everything was warmed up and I was only going to do a quick demo, I wasn't concerned for the remaining batter percentage. Landing with > 33% battery was well within safety margins.

Do you think either one of these could have been a factor?

I value your expert opinion!

Tim

 

[rvlasaty]

Check for a compass error. If you have a compass error it won't know which way is home.

 

[Meta4]

Do you think either one of these could have been a factor?

The landing and restarting the motors is probably the cause for the time of the start of the flight record.
But I don't think either of those things would have had any influence on the RTH.
Another thing I forgot to mention was that the incident wasn't caused by wind effects either.

 

[Traveler]

The wind was only in the neighborhood of 10 mph. Being Tehachapi, Ca., we always have wind and I fly it all the time. Also, when you look at the airspeed when it was drifting in ATTI, it was only drifting at about the 10 mph, plus or minus.

Upon sending the RTH command, it looked to me to be accelerating to a normal RTH speed.

As I said, I know I was reaching with my two above thoughts, and maybe we will never know why. Hopefully it will never happen again.

Thanks for getting back so quickly.

Appreciate you,

Tim

 

[Tommy J 111]

this is probably stupid but could the toy drone controlers have affected yours?

 

[Meta4]

this is probably stupid but could the toy drone controlers have affected yours?

No

 

[Traveler]

Updating this post, I returned to the same RC Field yesterday and attempted to duplicate the event, however every usage of RTH produced a normal outcome. This flyaway type event remains a mystery and hopefully a onetime occurrence.

 

[sinxa]

I was about to make a post "miss-heading RTH on Phantom4", but i search for such keywords and it led me to this thread. Yes.... it just happened to me, as long as i remember this is the second time.
First time it happened 3 days ago, its heading was about -30 degree where from it should, but unfortunately corrected right away before it started the GO-HOME run, i saw it on the recorded video on the SDCard, i'll post it soon on youtube and give the link here.
Second time just happened this afternoon, its heading was about -30 degree from where it should, and it went about 80-100 meters GO-HOME run, and then it suddenly stopped and corrected the heading it self and then continue to the actual home point. Please check the screenshot above. The AC icon located on the point where it corrected it's RTH heading.

I have no idea what kind of circumstances bring this weird behavior to my Phantom4, but i just wondering what if someday it heads to somewhere further than the home point???

Currently i have the latest app and firmware on both AC/RC.

I wish DJI acknowledge this problem.

 

[macoman]

View attachment 88587

I was about to make a post about "miss-heading RTH on Phantom4", but i search for such keywords and it led me to this thread. Yes.... it just happened to me, as long as i remember this is the second time.
First time it happened 3 days ago, its heading was about -30 degree where from it should, but unfortunately corrected right away before it started the GO-HOME run, i saw it on the recorded video on the SDCard, i'll post it soon on youtube and give the link here.
Second time just happened this afternoon, its heading was about -30 degree from where it should, and it went about 80-100 meters GO-HOME run, and then it corrected the heading it self and continue to the actual home point. Please check the screenshot above. The AC icon located on the point where it corrected it's RTH heading.

I have no idea what kind of circumstances bring this weird behavior to my Phantom4, but i just wondering what if someday it heads to somewhere further than the home point???

Currently i have the latest app and firmware on both AC/RC.

I wish DJI acknowledge this problem.

Could be the wind that pushed away your phantom and then the wind stop and was able to recover himself.

 

[Meta4]

its heading was about -30 degree from where it should, and it went about 80-100 meters GO-HOME run, and then it corrected the heading it self and continue to the actual home point.

That looks like an interesting mystery.
Perhaps if you share your flight data someone might be able to work out what happened.

Go to DJI Flight Log Viewer
Follow the instructions there to upload your flight record.
Come back and post a link to the report it provides​

Could be the wind that pushed away your phantom and then the wind stop and was able to recover himself.

That would have to be a very, very strong wind.

 

[sinxa]

Could be the wind that pushed away your phantom and then the wind stop and was able to recover himself.

I guess a very strong strong wind could drag its trajectory, but not the heading.
In fact, the wind is not too high to fly my drone...
And after you watch my video later, you can see it that the trajectory was really made by the phantom it self...

 

[sinxa]

That looks like an interesting mystery.
Perhaps if you share your flight data someone might be able to work out what happened.

Go to DJI Flight Log Viewer
Follow the instructions there to upload your flight record.
Come back and post a link to the report it provides​

Yes, i will post the flight log soon. And i rather pick the internal flight log rather than the one created by the apps, because the file will not contain the log while the AC was disconnected. Am i correct ?

 

[sinxa]

The video is being rendered, i'll post it soon after i uploaded to youtube.

 

[Meta4]

Yes, i will post the flight log soon. And i rather pick the internal flight log rather than the one created by the apps, because the file will not contain the log while the AC was disconnected. Am i correct ?

If your Phantom loses control signal, that part of the flight would not be recorded by the app.
But if it shows in the flight record replay like you show above, it's in the recorded flight data.