Sad Day: Lost the Anafi :(

[AnafiPilot1]

Just had a look at the ShowAnafiLog program.

Flying state for the last few seconds was 5 (emergency landing) Alert State was 3 (battery level critical), and Battery Carge Level = 1%

Finaly few entries where Alert State 2 (Cut out alert).

So this basically says software miscalculated the power needed for RTH!

 

[Liger 1956]

I wonder what the most efficient RTH speed is. Is it as fast as possible to get back in the shortest time or slow and steady to conserve battery? My guess is somewhere in between but does it also depend on what flying state you are in at the time (film or sport) and the maximum speeds that you have set in those states? I know that you said that it was a still day but does the software know which way the wind is blowing and how strong it is by comparing the GPS speed to the Anafi's motor speeds and tilt angle?

 

[AnafiPilot1]

Probably not - I still think the issue here was the battery level was not true - the long hover probably depleted more from the battery then the software allowed for, and the power demand of the RTH depleted it quicker than expected.

 

[AnafiPilot1]

Maybe in this situation if the RTH speed was slow it might of made it!!

 

[Rocky the FS]

So this basically says software miscalculated the power needed for RTH!

Another way of saying that the battery charge indications in FF6 are not real accurate. There have been many indications that this is true, resulting in crashes, lost drones, etc. which is why I included very conservative recommendations in my Drone School 101 text.

I believe from all these stories that a drone initiated RTH is a very risky emergency procedure and should not ever be relied on!

 

[AnafiPilot1]

I totally agree with you! however, situation meant I was forced to rely on the emergency RTH which did not work out for me!!

I can see from the logs the Anafi started the RTH at 10% battery level, which is just too low!!

 

[Joe_Scot]

I wonder what the most efficient RTH speed is. Is it as fast as possible to get back in the shortest time or slow and steady to conserve battery? My guess is somewhere in between but does it also depend on what flying state you are in at the time (film or sport) and the maximum speeds that you have set in those states?

My experience has been that RTH is always at 10 m/s regardless of the flight mode and settings. I have very slow settings for Film mode and pretty much everything at max for Sport mode.

 

[Jet]

Thanks for support guys!! Still really annoyed by what happened.

When I created the flightplan I did make sure it was within 500m but what I did not account for was the starting point and my launch position which was around 50m away from the first waypoint, hence my geofence getting triggered!

I did return to the RTH site after work - and it is just not around there, and the bushes and shrub growth around is so dense I just cannot imagine the Anafi falling through it, I would have expected to see if sitting on top of the vegitation!! I will keep looking as the area tends to thin out over winter.

There was no one around when it happened, but I was away from RTH point for over 15 minutes - I will leave a 'lost drone' poster in case - but I am treating it as a loss, I will have to see if my budget will allow me to get another Anafi soon!!

Some interesting info - I had a look at the Anafi page on the FF6 app which shows the last known position - the final flight is recorded as 22m 17s - so I suspect it came back on a low battery RTH, rather than me pressing the RTH button on the controller. The flightplan it was executing was only 3m 30s long.

View attachment 2606

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Oops...Didn't see the other posts...seems like you found it. So my conclusion below was right...but irrelevant at this point.
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I suspect that your Anafi ran out of battery before it was able to make it back and it is lying in a bush somewhere on it's RTH path back. A friend of mine did a test to see what the Anafi would do if it was executing a flight plan and ran low on battery...The answer is that it will return when the battery get's low but in my friends case the Anafi miscalculated the amount of battery required to RTH and on it's RTH flight it fell out of the sky because it ran out of battery...we believe it ran out of battery because the Anafi didn't take into account that the RTH height was 250 feet...and ascending and descending to/from that height consumed more battery than anticipated...bottom line is that his Anafi nearly made it back but not quite..luckily it only fell from about 10 meters on it's descent and was un-injured. So....I suspect that in your case it just didn't make it all the way back and it is sitting in a bush somewhere on the RTH path back.
Maybe it's worth spending an hour or two looking for it along the RTH path back.

 

[Liger 1956]

If you read the rest of the thread you will find that in post #7 he says that he has found it and following that is a discussion as to what had happened.

 

[papegoja]

....
Events happened as follows :-
...

3) First ERROR on my part - Geofence reached error pops up on controller while excuting the flightplan. I have my geofencing set at 500m and it turns out my flightplan was taking the Anafi out to around 550m from me! and guess what I do not have VLOS on the Anafi due to a couple of trees which from my elevated position are still too tall for me to see it!

4) So I quickly go in to settings and adjust the Geofencing to 1Km
...

Really sorry your Anafi cannot start but one thing kind of confuses me regarding geofence you mentioned.

Reaching geofence in flight plan flight should not be an issue I think and there is no need to take it into account (when executing flight plan)

For example see this video at 5:44:

It is only info that geofence has been reached but nothing happens because of that at least that is my current understanding.

 

[Chasbro]

In flight plan, I've found you have to be very careful not to let anything disturb the plan once it is running. That's why I never fly with geofence turned on.

 

[pmh1nic]

Nope - it was a very calm day.

I think the 18 minutes of hovering taxed the battery more than the software calculated - so when it started the RTH at 10m/s the battery just could not deliver.

That is what I am seeing from the graph.

A "calm" day at the surface can mean a gradual increase in wind speed with altitude, wind speed that can vary over a 20 minute flight. I think five or ten meters one way or the other is going to be difficult to blame on a miscalculation by the software given those variables. Another issue is whether it landed in the stream and was carried some distance (a few meters) before it settle in its final resting place.

As much as I appreciate the technology I wouldn't be counting on a software calculation that must account for moment by moment variables in conditions to get the Anafi back to a precise location

 

[AnafiPilot1]

In flight plan, I've found you have to be very careful not to let anything disturb the plan once it is running. That's why I never fly with geofence turned on.

I am no expert on geofencing and flighplans - If it is true that geofencing does not interupt the flightplan, then in my haste exiting out of the fly screen to update geofencing settings maybe cause for it stopping!

 

[Wezsh0T]

Interesting story. So, in the end, what would you have done differently? Waited for the Anafi to return after it returned due to low battery?

I lost connection with my Anafi once and hit the RTH button. After sweating for a few minutes, the Anafi returned and I manually brought it in for a landing. I reviewed the footage and realized that I could still control the Anafi even though I couldn't see it on my screen. In this instance, I had flown straight up to get footage of a waterfall, but trees had obscured the signal. If I had been patient enough, I could have just held down stick and I would have gotten the Anafi back a little faster.

Do you need a new motor PCB? I have a spare from a crashed Anafi I could send you. It's just gathering dust at the moment.

 

[AnafiPilot1]

What I should of done is not panic - stayed calm and thought it through. Instead I panic'd!! Jumped to the conclusion that the Anafi fell from the sky (for no reason what-so-ever) - in hindsight just waiting there for the emergency RTH would have probably worked out fine, I would have re-connected with the drone and landed it in a suitable location.

Thank you for the offer, very kind of you thanks - I am really not too sure what I am doing, Amazon have offered a refund which is fine, however when I bought it due to various discounts/deals etc, I got it for over 30% discount - so the refund will still leave me having to pay another £200 to buy another one!!!

Everything is working on the drone fine, except for the motor power supply error which I am sure is the motor pcb. Maybe it is worth me just replacing the motor PCB and keeping it!

 

[Lestat]

how long is it after connection lost that return to home is activated i was sure you could set the time limit in the app but can no longer find it

also found this youtube video

shows him make a flight plan and the drone fly past his gofence limits

 

[AnafiPilot1]

how long is it after connection lost that return to home is activated i was sure you could set the time limit in the app but can no longer find it

also found this youtube video

shows him make a flight plan and the drone fly past his gofence limits

Yes not sure, I think I said a few messages back - it is possible me trying to change the geofencing on the fly - caused the Anafi to stop the flightplan.

 

[Lestat]

lol sorry have just realised some on posted the exact same video did not notice that had just done a google search for geofencing and flight plan