Another auto-land question

[MarcusKeeler]

I know we've chatted about auto-land situations before but I'm wondering if something has changed in the firmware/app changing the process.

I was deliberately pushing the battery somewhat on farmland behind my property and as I was returning 'home' with the battery at 12% it decided to go into autoland. It was my previous experience that you could cancel this on the app by touching the "tap to cancel" or at least maintain a hover with throttle application and be able to navigate to a suitable forced landing site. Unfortunately it did not and down it went. I had a 350 meter walk to a grassy field to collect it so no harm done, but that could have equally have been a lake or worse.

So before the usual "just learn & fly within battery limits, distance" comments flow, I want to say that it's my Phantom and I am fully cognisant of the 'limits' of the batteries BUT auto landing at 12% is BS.

My P4 touched down with 11% battery remaining and the thing remained 'on' and transmitting data & video for the next 20 minutes while I made my way to it. When I got to it, the batt level was like 8% and all cells perfectly balanced, so the battery had not 'crashed'.

The only thing I will say is that the battery was pretty warm, marginally warmer than previous full flights, the ambient temperature was quite hot too (30deg). That being said, I am not aware of temperature related actions inside the flight software, plus of course, the internal resistance of Lipos reduces with heat making them more efficient although I will grant you that there are limits.

So anyhoo, when did they stop allowing us to delay auto-land via throttle and when did they disable the "tap to cancel"? You could ask why they have the App give you a chance to cancel at all if they are going to ignore it.

Lastly, how are we running the Lipos down to 5% now? Just having it sit doing nothing whilst the lipos slowly creep down to 5% is suicide for the lightbridge transmitter without airflow.

 

[msinger]

I was returning 'home' with the battery at 12% it decided to go into autoland. It was my previous experience that you could cancel this on the app by touching the "tap to cancel" or at least maintain a hover with throttle application and be able to navigate to a suitable forced landing site.

You cannot cancel the auto landing that occurs when the battery reaches the critically low level. However, you should be able to move the throttle stick to the full up position and steer your Phantom to a better landing location.

 

[MarcusKeeler]

You cannot cancel the auto landing that occurs when the battery reaches the critically low level. However, you should be able to move the throttle stick to the full up position and steer your Phantom to a better landing location.

Hmmm, weird. The thing was totally non responsive, it went from flying happily to "I'm landing NOW". I had no control whatsoever and I've previously been able to hover around relatively freely until the 5% deep cycle point. Something has changed.

 

[stones]

Hmmm, weird. The thing was totally non responsive, it went from flying happily to "I'm landing NOW". I had no control whatsoever and I've previously been able to hover around relatively freely until the 5% deep cycle point. Something has changed.

Flying down to the "5% deep cycle point" sounds like risky business to me. Imho, I think your putting your battery through undue stress, at least, from what I've been reading on the forums here.

 

[MarcusKeeler]

Flying down to the "5% deep cycle point" sounds like risky business to me. Imho, I think your putting your battery through undue stress, at least, from what I've been reading on the forums here.

It's what DJI say you need to do. With my Inspire the app tells me I HAVE to do it from time to time and bugs me until it's done.
I don't necessarily think it's the best thing for the batts but the App constantly whining about it needing to be done is compelling.

 

[stones]

It's what DJI say you need to do. With my Inspire the app tells me I HAVE to do it from time to time and bugs me until it's done.

Does the app tell you to do this with the P4?

 

[MarcusKeeler]

To be fair I haven't seen it yet. My P4 has like 20 battery cycles on it and was expecting the message soon based on my Inspire experience. My P4Pro has even less, 10 cycles, so no.
As I see it, the battery percentage isn't literal anyway, it's a measure of available 'programmed' flight time. 0% on the APP is total shut down of course but the battery isn't 0v, it will never reach that due to the battery board protecting it.
When I've deep cycled the Inspire it's relatively happy to hover until you voluntarily land although they do say to do it at a height of 3 feet or so "just in case' LOL

 

[Brockrock]

Hmmm, weird. The thing was totally non responsive, it went from flying happily to "I'm landing NOW". I had no control whatsoever and I've previously been able to hover around relatively freely until the 5% deep cycle point. Something has changed.

At the time, were you flying using one of the Advanced Flight Modes like Home Lock or Course Lock? I saw a video the other day where a guy was doing a long distance flight in Home Lock to assure straight lines out and back, and when it went Critical Low Battery, he had the same experience as you. He had no control to move it to a safer place. It has been discussed in the video comments that the copter first had to cancel its Advanced Flight Mode - in this case Home Lock - and then begin its landing sequence resulting in the remote having no control of the copter.

 

[MarcusKeeler]

At the time, were you flying using one of the Advanced Flight Modes like Home Lock or Course Lock? I saw a video the other day where a guy was doing a long distance flight in Home Lock to assure straight lines out and back, and when it went Critical Low Battery, he had the same experience as you. He had no control to move it to a safer place. It has been discussed in the video comments that the copter first had to cancel its Advanced Flight Mode - in this case Home Lock - and then begin its landing sequence resulting in the remote having no control of the copter.

Good thinking, but no. I was originally on RTH but dropped to manual flight about 1km prior to that.

You're talking about "Nevermindyourown" on Youtube. His mistake was that he was coming back to himself backwards in HL mode, when it went to RTH it dropped HL, he couldn't figure out why it was flying away from him after he cancelled RTH because he'd forgotten it was in HL to begin with hahahaha..

 

[Brockrock]

Good thinking, but no. I was originally on RTH but dropped to manual flight about 1km prior to that.

You're talking about "Nevermindyourown" on Youtube. His mistake was that he was coming back to himself backwards in HL mode, when it went to RTH it dropped HL, he couldn't figure out why it was flying away from him after he cancelled RTH because he'd forgotten it was in HL to begin with hahahaha..

Yes, you are absolutely correct now that I've looked at it again. I have actually learned quite a bit from his antics. He pushes the limits from time to time and loves experimenting with all that these things can do.

I am expecting my P4 back tomorrow after DJI hopefully repaired a VPS issue that I was having and am looking forward to getting back out again. Happy Flying!

 

[Duchunter]

If that happens again flip it to sport mode and back. If it is an ifm lockout then going to sport mode and back will cancel it. Even if its just a glitch I think that would kinda bootstrap it back in line.

 

[Duchunter]

My p4 landed 50-75 feet away from the home point on a rth once. I wasn't watching it land. I had just got it and I was busy telling somebody all about it. I heard it coming down and the next thing I know I don't hear it, but its not home. My heart skipped a beat. It landed next to a tree in the street. Just plain luck it didn't come down in a tree on day one. Still have no idea why. Hasn't done it again but I don't use rth to get back, I usually fly it home. I might let rth get me some of the way on long flights but I always hand catch so I fly it in manually. Thy will glitch sometimes and do crazy things.

 

[MarcusKeeler]

Yea, I rarely use RTH and even when I do it's just to get it back into my ballpark whilst I mess with an app setting or otherwise handle a distraction and agreed on the hand catching, I'll fly it to within 10 feet of me at 5ft height, let it settle and then approach it and grab it softly. I think the only times mine has landed onto it's skids are the autoland thing and once when i deliberately landed on somebody's flat roof for a dare.

 

[PhantomFun]

Hi all, I have had the same unfortunate experience of being forced to land. I also agree why does the app tease us with a red X to cancel auto land.

Most recently while over the Pacific Ocean I had gotten a motor overheating error message and then a battery overheating error message ( I was flying hard against the wind). My P3 went into forced landing while I was in RTH. The red X was greyed out to cancel the forced landing (it used to work several firmware updates ago). I had practiced this scenario before when I first learned I could no longer cancel forced landing. At that time of first learning cancel landing no longer worked, I got lucky enough that the P3 forced landed on a parked car safely, after the battery became critically low and I was forced to land (I didn't know at the time I could throttle up to stay in the air).

After that experience, I practiced how to overcome this by bringing the battery way down and once forced landing went into effect, I learned I could throttle up to over come it. I did this same thing Monday as the P3 was coming down, fortunately it had made it close to home, yet seemed to be coming down pretty fast and was still semi near the water.

I agree that I should be able to cancel out of forced landing. I'd rather the copter crash land on land, as opposed to land correctly on water. I was lucky that full throttle up still worked for me for overriding the forced landing. Seems I may test the theory again given the recent post of that no longer working...

Is there a path to let DJI know we'd like to have the cancel out of forced landing reactivated?

Thanks,
Mark