It went down and I couldn't stop it.

[sar104]

This event had nothing to do with either of the battery warning levels or the computed RTH or autoland battery levels. None of those were reached:

The cause seems to have been a smart battery issue:

There were multiple instances of "BatteryCommunicateError" before the battery went to a status that required autolanding.

 

[MotorCycle-Man]

SAR 104.......how did you extract / find these very important files to show the battery related errors ?

I'd Love to be able to do this too someday...Thank You.

 

[sar104]

SAR 104.......how did you extract / find these very important files to show the battery related errors ?

I'd Love to be able to this too someday.

They are all in the txt log, with the field names as shown in the graph legends. The warning levels are just that - warnings at levels preset in the GO app. The smart battery go home level is computed on the fly by the FC based on distance from home (it doesn't seem to take wind into account) - it triggers RTH and can be overridden by the pilot. The smart battery land level is computed based on altitude - it triggers autolanding and cannot be overridden.

 

[Loz]

They are all in the txt log, with the field names as shown in the graph legends. The warning levels are just that - warnings at levels preset in the GO app. The smart battery go home level is computed on the fly by the FC based on distance from home (it doesn't seem to take wind into account) - it triggers RTH and can be overridden by the pilot. The smart battery land level is computed based on altitude - it triggers autolanding and cannot be overridden.

Very helpful info thanks. So at the risk of asking you to repeat yourself / yourselves I now understand:

1. User battery charge warning level settings are informative for user only and have no effect on flight automation?

2. RTH calculated and triggered by low battery level and is done by FC based on distance from home point, to try make sure AC is not left stranded? [Can be user overridden]

3. Smart battery landing, automatically triggered by altitude?
- I’m not getting this one, could someone explain this trigger please, ideally with an example. I’m guessing it’s based on battery charge and a calculation of height AGL (which of course can only be relative to Home/Take off barometric pressure measured). How does pilot know AC battery charge is approaching this trigger level for FC (aside from user set low battery warnings, assuming connection with AC and app display of charge).

Thanks in anticipation

 

[Deleted member 62848]

I only have one niece and she is a frail thing that wouldn't get her hands dirty. That place is dangerous area to venture, unless you like climbing cliffs and rattlesnakes. I like rattlesnakes, they taste good. I can't do cliffs anymore is an understatement.
I wanted to post a $100 US reward, but my wife was against it figuring it would be a broken piece of junk.

Never tryed snake, they say it taste like chicken,anyway I don't think there be much damage unless some trees jumped out because it auto landed which is a good decent (unless something there),mayby broken pro or minor damage,,this annoys me cause I can't help,I only have one p4 and can't give that away as bad as I feel, don't give up,get search and rescue club on the phone for some extra practice,,they might be glad to help

 

[sar104]

Very helpful info thanks. So at the risk of asking you to repeat yourself / yourselves I now understand:

1. User battery charge warning level settings are informative for user only and have no effect on flight automation?

2. RTH calculated and triggered by low battery level and is done by FC based on distance from home point, to try make sure AC is not left stranded? [Can be user overridden]

3. Smart battery landing, automatically triggered by altitude?
- I’m not getting this one, could someone explain this trigger please, ideally with an example. I’m guessing it’s based on battery charge and a calculation of height AGL (which of course can only be relative to Home/Take off barometric pressure measured). How does pilot know AC battery charge is approaching this trigger level for FC (aside from user set low battery warnings, assuming connection with AC and app display of charge).

Thanks in anticipation

If you look at the first graph that I posted above you will see all the necessary information. The blue line is the battery level. The green line is the FC estimation of of the battery level at which it will need to initiate RTH (based on distance from home point), and the red line is the level at which it estimates that it will need to commence landing (based on altitude relative to takeoff - it doesn't know AGL). So when the blue line crosses the green line it will attempt to initiate RTH, and when the blue line crosses the red line it will commence autolanding.

 

[Loz]

If you look at the first graph that I posted above you will see all the necessary information. The blue line is the battery level. The green line is the FC estimation of of the battery level at which it will need to initiate RTH (based on distance from home point), and the red line is the level at which it estimates that it will need to commence landing (based on altitude relative to takeoff - it doesn't know AGL). So when the blue line crosses the green line it will attempt to initiate RTH, and when the blue line crosses the red line it will commence autolanding.

Thank you, explanations appreciated.
If I may, if AC looses GPS fix for whatever reason, reverts to ATTI etc. I assume RTH due to low battery battery is unable to function & therefore does nothing (hovers probably) until, if at all, GPS reception resumes?

Can you confirm (think you just did) both the user settings on battery level in app are to alert the user only, and do not influence FC at all?

Again thanks

 

[msinger]

User battery charge warning level settings are informative for user only and have no effect on flight automation?

That's correct. Post #17 above shows the user warning settings have no effect on the flight automation. The video in post #7 shows the same thing.

RTH calculated and triggered by low battery level and is done by FC based on distance from home point, to try make sure AC is not left stranded? [Can be user overridden]

That's correct. In this case, RTH was not auto triggered since the OP had that setting disabled.

How does pilot know AC battery charge is approaching this trigger level for FC

Watch the video in post #7 above.

That's how it normally works. However, as @sar104 pointed out, the battery was deemed to be critically low sooner than expected in this case.

 

[sar104]

That's correct. Post #17 above shows the user warning settings have no effect on the flight automation. The video in post #7 shows the same thing.


That's correct. In this case, RTH was not auto triggered since the OP had that setting disabled.


Watch the video in post #7 above.

That's how it normally works. However, as @sar104 pointed out, the battery was deemed to be critically low sooner than expected in this case.

The battery triggered the autolanding by switching to an unspecified ("Other") condition after all those communication errors. The smart battery system appeared to stop updating at the end, but the FC voltage monitoring shows that the voltage continued to drop:

 

[Fly Dawg]

@sar104 Would you agree that this value had something to do with the comm errors do you? It was True for the entire flight.

 

[sar104]

@sar104 Would you agree that this value had something to do with the comm errors do you? It was True for the entire flight.

View attachment 104148

That flag is always set to "True", so probably not related.

 

[Loz]

Got it gents, appreciate your experience and time, thank-you.

 

[Fly Dawg]

That flag is always set to "True", so probably not related.

Interesting, but unusual in relation to most of the other flags. Took a wag at it anyway......

 

[African wildlife]

Mr Rootman: Your country has a proud record of countless hikers who greatly appreciate the outdoors and a challenge. Wouldn’t it be worth a simple appeal for help to retrieve your drone from those younger than yourself? Human behaviour can often be disappointing, to say the least, but those who like the outdoors are usually above-average and can positively surprise.

 

[WV. Rootman]

In a much earlier post in the loss of a drone by ways of a fly away !...i added that to maybe get the drone back beings it was lost..that the small name and address labels we all get around CHRISTmas time would have been nice to have stuck inside the squares on the sides of the battery's......ever one of my battery's has the name address city labels on them and i was laughed at....I imagine IF the guy that did that to me (Laughed about my idea).... encounters a fly away....he will wish he had done my idea...and i don't wish bad things on No body period ! ever one should have a name address and city and even a phone number in side their drone OR in a small water proof packet taped to the back side surface of the camera.....Mines got it their too !..............W.V Rootman....i hated to read about the loss !

Life is full of adventure. Some big, some small. This is a small one. If my wife and I would have our health, we would be on top of the world. I have very little else to concern myself with. My in-laws is another story.
I have a frail mother and father in law we were about to visit in Panama City, Fl. next week. Hotel rooms have been reserved for weeks. I know when to travel? They had to evacuate their home with family there and drove to Jacksonville , Fl. A 4 hour trip, took them about 10 hours because of their condition, traffic and a blown tire. She is on oxygen. I just looked at the track of the storm. The exact center will pass about 15 miles east of their house. I hope the have a house after today. They have huge pine trees all around their house.

 

[WV. Rootman]

Mr Rootman: Your country has a proud record of countless hikers who greatly appreciate the outdoors and a challenge. Wouldn’t it be worth a simple appeal for help to retrieve your drone from those younger than yourself? Human behaviour can often be disappointing, to say the least, but those who like the outdoors are usually above-average and can positively surprise.

There is much truth in what you say. Photographers at this time of year (fall colors) with the stamina, may try to photograph the second falls. It probably landed and hit a tree over the third falls, which is not as photogenic. Each falls being progressively more difficult to get to.
My wife is the big factor in saying it isn’t worth it.

 

[WV. Rootman]

This event had nothing to do with either of the battery warning levels or the computed RTH or autoland battery levels. None of those were reached:

View attachment 104140

The cause seems to have been a smart battery issue:

View attachment 104141

There were multiple instances of "BatteryCommunicateError" before the battery went to a status that required autolanding.

I have 2 batteries. This was an issue 2 weeks ago with both batteries in the P4. The issue never affected any of the operations or flight time with the p4. One battery I just bought new. I was in contact with DJI about it, because this was a replacement P4 they had sent me. It never happened on the other P4 I had. I should have sent the P4 back. I cleaned the contacts in the P4 and I never saw the errors come up again. I flew it about 6 times with no more battery signal error. I have to concentrate on my flying. I not very multitasking. My wife helped me watch for it, because I cannot bring it up in the records. I was having a thrilling time flying over that canyon and to be able to get a picture of the second falls. A place I would never be able to get to by land. Also, I was standing on a point jetting out over the canyon and the shots were amazing.
My cognitive skills have been a depressing issue as I age. I think slower and have to concentrate harder on what I do.
I thank you for your wonderful mind. You are a great asset to me and this forum.
#1 I had poor judgement.
#2 It was a defective P4 , I should have sent it back.
Even if I would retrieve it. It is a defective drone.

 

[WV. Rootman]

They are all in the txt log, with the field names as shown in the graph legends. The warning levels are just that - warnings at levels preset in the GO app. The smart battery go home level is computed on the fly by the FC based on distance from home (it doesn't seem to take wind into account) - it triggers RTH and can be overridden by the pilot. The smart battery land level is computed based on altitude - it triggers autolanding and cannot be overridden.

The battery warnings never come up in the go app. on my mobile. I have looked for them. Yes, I know where to look.

 

[Fly Dawg]

The battery warnings never come up in the go app. on my mobile. I have looked for them. Yes, I know where to look.

Assuming you are looking at the log files....look right here.....

 

[Wilbur]

There is much truth in what you say. Photographers at this time of year (fall colors) with the stamina, may try to photograph the second falls. It probably landed and hit a tree over the third falls, which is not as photogenic. Each falls being progressively more difficult to get to.
My wife is the big factor in saying it isn’t worth it.

If I still lived in West Virginia I'd gladly search for it. Unfortunately I'm on the other side of the country now. Good luck!