Testing Follow me-mode, fly away and crash :( - happy ending! :)

I think when a person sees a bad GPS location in his phone, most people's instinct is to walk around a bit so that it can correct. Why? Because it makes sense. Also because it works. Maybe your instinct is to stand still. I don't think most people are inclined to freeze when they have a bad GPS location on their phone. But maybe you're right. Maybe standing perfectly still is the best way to improve a bad GPS location on the phone.
I think it doesn't make much difference if you stand still or move around. Provided that 1) the moving isn't too fast and 2) the moving exposes more satellites (like maybe if you're standing under a tree, etc and moving brings you out from under the tree).
 
That's exactly my point. If you have a bad GPS, there is probably a reason for it. You could have a big oak tree trunk blocking a satellite. What do you do?
 
I was in a hurry yesterday and didn't watch the video. Now, I can't find it. But, wasn't the point of the video that the tablet had the correct values for tablet location? I already knew that; that's why I didn't watch it. Could you post another link to it please.

Yes, that was the point of the video, so you don't have to watch it. :) However, the link to the video is in a conversation I started with you yesterday.
 
I took another look at the output of @ferraript 's converter. The flyTime that would match the flightTime column in DatCon's .csv is there. It's called "OSD.flyTime" (column AV in the latest). It's units are seconds whereas the DatCon's flightTime units are milliseconds. But the sample points are the same, so it should be easy to sync the two outputs.
@AndersGB

Many thanks! I will check this. I think it will take a day or two before I have the time to do it though, but I will come back to you.

The P3 is sent away now to DJI. Hopefully they will replace it as a warranty issue, but I'm not that sure. It will take 3-4 weeks they said in the local shop.
 
Thank you very much for posting your experience with Follow Me mode.

Yes, they seem to be more common than I thought also, I hadn't read about any such event before, but now several have posted about similar experiences.

During this flight, I tested Follow Me mode two times first, without any problems. But at the third time, it just flew away. Did yours fly away when initiated also?

It's a little bit strange that P3 got an incorrect GPS location for the RC at the instant when I activated Follow Me, but as Marknmd and others have said, it is important to move around a little to ensure a god GPS reading for the tablet. It might be difficult, but an essential security measure. And also be ready to switch to P mode all the time during a Follow Me mission.


For my fly-away incident, I was walking around a large open area (tee box on a golf course) as I was setting up the aircraft height and stand-off distance to begin the flight. It took me 30-45 seconds to get the aircraft at the desired location before I activated the "Follow Me" mode. The fly-away happened almost immediately after I initiated the "Follow Me" mode on the iPhone 5s screen. Strangely enough, It was also my 3rd "Follow Me" flight of the day. During the first 2 flights, it worked perfectly as it followed my moving location in a golf cart going down a fairway of our local course.

The Google maps location (via Healthy Drones) showed my correct transmitter location on the tee box during the entire incident. The bad coordinates "spike" must have (could have?) occurred when I switched to the "Follow Me" mode. After I recovered the aircraft from the fly-away condition, I flew it back to the tee box where I was standing and forced the system to record another Home location. I tested all of the flight controls and they appeared to work. Nervously, I then tried another "Follow Me" mode activation and it didn't fly away so we got in the golf cart and drove it on the cart path to the putting green without incident.

Here is the Healthy Drones link: http://healthydrones.com/main?share=MjkwNg

FlatSpin
 
For my fly-away incident, I was walking around a large open area (tee box on a golf course) as I was setting up the aircraft height and stand-off distance to begin the flight. It took me 30-45 seconds to get the aircraft at the desired location before I activated the "Follow Me" mode. The fly-away happened almost immediately after I initiated the "Follow Me" mode on the iPhone 5s screen. Strangely enough, It was also my 3rd "Follow Me" flight of the day. During the first 2 flights, it worked perfectly as it followed my moving location in a golf cart going down a fairway of our local course.

The Google maps location (via Healthy Drones) showed my correct transmitter location on the tee box during the entire incident. The bad coordinates "spike" must have (could have?) occurred when I switched to the "Follow Me" mode. After I recovered the aircraft from the fly-away condition, I flew it back to the tee box where I was standing and forced the system to record another Home location. I tested all of the flight controls and they appeared to work. Nervously, I then tried another "Follow Me" mode activation and it didn't fly away so we got in the golf cart and drove it on the cart path to the putting green without incident.

Here is the Healthy Drones link: http://healthydrones.com/main?share=MjkwNg

FlatSpin
Was it the first Follow Me of that flight? The others occurred on the 2nd or 3rd Follow Me of a flight.
 
Was it the first Follow Me of that flight? The others occurred on the 2nd or 3rd Follow Me of a flight.
My fly-away event occurred the 3rd consecutive flight of the day. On flight #3, I activated the "Follow Me" mode twice during that flight session. My first activation occurred about 50 seconds into the flight (Healthy Drones log, Point E) and it resulted in the fly-away. I recovered it about 63 seconds into the flight (Healthy Drones log, Point G) and while hovering at 35', I then I reset the Home point at 103 seconds into the flight (Healthy drones log, Point H). I re-activated the "Follow Me" mode the second time at 133 seconds into the flight (Healthy Drones log, Point I). The second attempt worked and the aircraft followed me until I switched back to "P" Flight mode at 5 minutes and 30 seconds into the flight (Healthy Drones log Point L).

I hope this helps explain my chain of events. :)

FlatSpin
 
Hi,

After some 40+ nice flights I decided to test the "Follow me"-mode, after some initial short flying. I was practicing on a large field and maybe did some foolish things. After initiating the "Follow me"-mode, which must be done with the drone above 10 meters, I thought it was a little high and took it down to maybe 5-6 meters, and it still worked ok. I tried the "Follow me"-mode a couple of times, walking around on the field, happy that it went so good. But suddenly the drone just took away, full speed away from me. I saw a message on the screen "Compass error" I think, pressed the RTH button in panic, but nothing happened and the drone crashed into a tree. It all went very fast.

The gimbal is broken and there are som scratches on the drone, :( ,but luckily enough no one got hurt. I got really scared.

I've tried to start the drone, without propellers, and it does start and gets contact with the RC. It updates the Home Point, and the led's are flashing green. However, when I shut down the drone, pressing the battery button twice, the drone doesn't shut down immediately. The leds on the drone and the red led on the battery are flashing a couple of seconds before it shuts down. I've never seen that before. Anyone knows what it means?

I would appreciate if anyone can help me to understand what happened. What did I do wrong? Or was it something wrong with the drone (even though I don't think so)? I'm planning to repair or buy a new one but I'm a little bit scared now. What if it had flown far away and crashed into a person?

I've uploaded the flight record to Healty Drones here:
HealthyDrones.com - Innovative flight data analysis that matters

Looks like dji owes you a new bird. Personally I would fight them for it because that one has proven unfaithful. That's just me. It's to dangerous to fly shady hardware especially after a crash that everything isn't checked out.

And the file is attached also.



Sent from my iPhone using PhantomPilots mobile app
 
I had a similar thing happen to me a couple of weeks ago. I posted about my experience here. Not had much luck in figuring out went wrong. Opened a case with DJI support and sent them the DAT file. No answer as yet :( totally sucks.. help!

Follow me mode failed
 
Yes - I've posted that video on this site at least a half dozen times.

Re the video and its explanation of flyaways, basically the same problem here, it's just different. :) Instead of the aircraft recording a bad home point, the phone/tablet is sending a bad GPS fix. Same thing really. But it's certainly not DJI's fault and it's not the pilot's fault either.

This situation is a little unusual. Yeah, it happens, but I wouldn't say it's a chronic problem. It was bad luck for the OP.

It's the phone/tablet's fault. What can we do about it? How can we keep this from happening?

One thing we could do is try to use a device that has a solid GPS module. And that's kind of tough to research, since phones/tablets don't tell us how many satellites they get (the idea being the more satellites, the least likelyhood of a bad fix). But maybe that cheap tablet from South Korea wasn't the best idea. How about a phone/tablet that uses GLONASS as well as GPS? That would be nice. During Follow Me, we could hold the controller out a bit, rather than close to our belly (a big belly will block a satellite or two or three). Otherwise, it seems to me we must be sure to use follow me in wide open spaces. We should try to move around rather than stand so that the tablet is inclined to reassess our location. We might check uavforecast.com prior to flight and see how many GPS satellites (not GLONASS) are visible. And we should check the elevation mask depending on where we are walking (valley/desert) because it's not like our phone/tablet is going to gain satellites with elevation. And most importantly, we should be ready and know exactly how to take our aircraft out of Follow Me in an instant.
I've had good luck using the Garmin glo.


Sent from my iPad using PhantomPilots mobile app
 
My fly-away event occurred the 3rd consecutive flight of the day. On flight #3, I activated the "Follow Me" mode twice during that flight session. My first activation occurred about 50 seconds into the flight (Healthy Drones log, Point E) and it resulted in the fly-away. I recovered it about 63 seconds into the flight (Healthy Drones log, Point G) and while hovering at 35', I then I reset the Home point at 103 seconds into the flight (Healthy drones log, Point H). I re-activated the "Follow Me" mode the second time at 133 seconds into the flight (Healthy Drones log, Point I). The second attempt worked and the aircraft followed me until I switched back to "P" Flight mode at 5 minutes and 30 seconds into the flight (Healthy Drones log Point L).

I hope this helps explain my chain of events. :)

FlatSpin
A very odd coincidence I must say. It happened the third time Follow Me was activated for both of us. It seems more and more like a bug in the system.
 
I had a similar thing happen to me a couple of weeks ago. I posted about my experience here. Not had much luck in figuring out went wrong. Opened a case with DJI support and sent them the DAT file. No answer as yet :( totally sucks.. help!

Follow me mode failed
I've sent my crashed P3 to DJI, but I really don't think they will take it on warranty, I hadn't upgraded to the latest software version. They can always claim that, an easy way out. :(

I read your post. I will probably buy a new one, but I also will never use Follow Me again. :(
 
I had a similar thing happen to me a couple of weeks ago. I posted about my experience here. Not had much luck in figuring out went wrong. Opened a case with DJI support and sent them the DAT file. No answer as yet :( totally sucks.. help!

Follow me mode failed
It took the China Support office 3 weeks to figure out my incident issues. Once they started looking into my ticket, they were pretty reliable about emailing back and forth for additional information. There is a US Customer Support phone number and email address, but they were less responsive. I'm not sure if the two Customer Support locations were internally coordinating on my ticket or not.

Here are the Customer Support contact points they gave me.

North America
Phone: +1 (818) 235-0789, Mon-Fri 9:00am - 5:00pm (PST)
E-mail: [email protected]

EU Member Countries
Phone: +49 (0) 9747-9304200, Mon-Fri 9:00am - 5:00pm (Central Europe Time)
E-mail: [email protected]

Japan
E-mail: [email protected]
 
It took the China Support office 3 weeks to figure out my incident issues. Once they started looking into my ticket, they were pretty reliable about emailing back and forth for additional information. There is a US Customer Support phone number and email address, but they were less responsive. I'm not sure if the two Customer Support locations were internally coordinating on my ticket or not.

Here are the Customer Support contact points they gave me.

North America
Phone: +1 (818) 235-0789, Mon-Fri 9:00am - 5:00pm (PST)
E-mail: [email protected]

EU Member Countries
Phone: +49 (0) 9747-9304200, Mon-Fri 9:00am - 5:00pm (Central Europe Time)
E-mail: [email protected]

Japan
E-mail: [email protected]

Many thanks! I will email the support in EU.
 
I've had one near fly-away in Follow Me mode. There wasn't anything particularly special with what I was doing. I thought maybe it had to do with already being on the go when entering Follow Me mode, but I tried that again without issue. Regardless, my default response to any uncommanded movements is ATTI mode. That seems to be as close as you can get to full manual control, where faulty sensors, computers, etc. can't drive control inputs.
 
I don't know
you can use my converter and try
Finally I've had the time to do this. And your converter is great, many thanks. I will post some diagrams and findings thanks to your work.

However, I believe that the headings of column FT and FU should change place, otherwise it doesn't make sense to my diagrams. :)
 
I took another look at the output of @ferraript 's converter. The flyTime that would match the flightTime column in DatCon's .csv is there. It's called "OSD.flyTime" (column AV in the latest). It's units are seconds whereas the DatCon's flightTime units are milliseconds. But the sample points are the same, so it should be easy to sync the two outputs.
@AndersGB
Finally I've had the time to look at this a little deeper. And I must say that the results are very interesting.

My idea was to check if the GPS values for the RC/tablet, stored in the P3, in the .DAT file, did match with the GPS values for the RC/tablet stored in the Flight Record, stored on the tablet.

BudWalker has helped me a lot with this, and encouraged me to look into this a little further. I've got the .DAT file from him.

Here is the graph for the GPS values for the RC/tablet, stored in P3, in the .DAT file. It is the same graph as BudWalker has shown in a post earlier in this thread.
2_RC position_DAT file.jpg

Both BudWalker and I thought it very strange that the glitch in the GPS data occurred at the exact same moment as I activated the Follow me function the third time, at 376 ms, and we both thought that it may be a bug or error in the system. Especially since the replay of the flight in my iPad didn't show any strange behaviour.

The main hypothesis was otherwise that it was the tablet that introduced the error, that the GPS on the tablet suddenly had "jumped away" for a while (sorry for my English) and caused the fly away and accident.

And here is the graph for the GPS values for the RC/tablet, stored in the Flight Record file. Many thanks to ferraript for his work with the TXT to CSV converter.
1_RC position_flight record.jpg

No glitch, which indicates that the GPS values from the tablet (iPadMini4, celluar) were correct all the time. And that there might be a possible error in the communication between the RC and the P3A, or a software bug in P3A, for Follow Me missions. Other opinions?

I'm planning to send this to DJI, since I'm claiming the accident as a warranty issue, what do you think?
 
WOW! things seem to be coming together! Really seems like a link between the R/C and the quad, OR when a switch change occurs (switching to F mode), erroneous data is sent to the quad or the data stream gets corrupted and introduces a glitch that the quad sees and interprets as valid data (which it is not), and the quad reacts.
NOW finding WHERE that corruption is actually occurring should be the next step.
1) operator error.... doesn't appear to be
2) tablet GPS... seems ok
3) R/C... could be
4) quad controller... could be
5) other possibilities? who knows (yet)

Maybe some averaging needs to be incorporated to smooth out any large position changes that may be in error, like the huge spike that has been seen.
That spike in reality, isn't possible.
 
  • Like
Reactions: Mark The Droner
I think we have discovered a system error in the device-r/c controller-aircraft connection when activating the "Follow Me" mode. These events are not "Operator Errors" like many were thinking! For my incident, and with all this additional information coming to light, I am sure that my device was working fine and the fault was with the DJI system. Now to isolate what part of the system is at fault... I'm not holding my breath for DJI to take the lead on this.
 
I wouldn't bother with follow me, it's a gimmick anyway with a remote, if you had a wearable watch would make more sense to use it


Sent from my iPhone using PhantomPilots mobile app
 

Members online

Forum statistics

Threads
143,066
Messages
1,467,354
Members
104,933
Latest member
mactechnic