Remote control signal lost

[AlexSP]

I'm still getting the feeling for the Mavic but already can tell it won't reach anything near 7km. Even in unnobstructed, open and Wi-Fi free countryside area.

In the exact same place and course that my P3P (GL300B unmodified controller and old FW) goes 15.000ft without dropping a single bar, my new Mavic starts losing RC signal at about 3000ft.

I'm still breaking my batteries so I wasn't able to fly further, and TBH the video and RC were locked in tight. Once they're good I'll try a long range flight to check how it performs, but judging from what this I have the impression it won't touch the old Phantom.

PS.: Lots of warnings of all kinds - wind, compass, too much saturated fat, everything I wasn't used to have with Phantoms and Inspires, but seem not to affect flight in any way so I just keep piloting it as I'm used and so far so good LOL

 

[BudWalker]

Here is a link to the DAT files. I uploaded all for yesterday. The last one (latest time) is the flight in question.

Dropbox - Mavic Pro DAT Files 12-28-16

I looked at this flight some. In summary, the Mavic behaved normally - there wasn't really an incident. During an RTH the Mavic (and the P3) will hover for about 3 or seconds after it gets to the homePoint coords. After that it begins it's descent. In this flight after the Mavic climbed to the RTH height and the pilot repeatedly applied full back throttle but would then release the throttle to the neutral position.

Each time the throttle was released the Mavic responded by starting to climb to the RTH height.

The Mavic actually switched to AutoLanding at time 147. The RC connection was broken at 153 and the Mavic started it's descent. In addition to the throttle input there were small aileron and rudder inputs that may have delayed the descent phase.

The entries in the eventLog stream that @f3honda4me referenced about being close to the ground happen because it's in autoLand mode and getting really close. They happen every time an auto land is done.

 

[Logger]

So by switching off the remote, conflicting commands ceased and the Mavic got on with its RTH process. So sit on your hands in future.
Alternatively whilst hands off, pressing Pause should stop the RTH process. Then wait to confirm RTH has actually stopped before taking over.

BudWalker what was the battery state on landing. Did it actually get to battery critical? I suspect not and it just completed the RTH process once the interruptions stopped.

 

[BudWalker]

So by switching off the remote, conflicting commands ceased and the Mavic got on with its RTH process. So sit on your hands in future.
Alternatively whilst hands off, pressing Pause should stop the RTH process. Then wait to confirm RTH has actually stopped before taking over.

BudWalker what was the battery state on landing. Did it actually get to battery critical? I suspect not and it just completed the RTH process once the interruptions stopped.

Another method would be to hold the throttle back and not let it return to the neutral position.

I'll have to reverse engineer the .DAT some more before I can tell you about the battery status.

 

[f3honda4me]

Thanks Bud! Your program is great I just need to keep learning how to use it! Thanks for the correction.

I looked at this flight some. In summary, the Mavic behaved normally - there wasn't really an incident. During an RTH the Mavic (and the P3) will hover for about 3 or seconds after it gets to the homePoint coords. After that it begins it's descent. In this flight after the Mavic climbed to the RTH height and the pilot repeatedly applied full back throttle but would then release the throttle to the neutral position.
View attachment 3242
Each time the throttle was released the Mavic responded by starting to climb to the RTH height.
View attachment 3243
The Mavic actually switched to AutoLanding at time 147. The RC connection was broken at 153 and the Mavic started it's descent. In addition to the throttle input there were small aileron and rudder inputs that may have delayed the descent phase.

The entries in the eventLog stream that @f3honda4me referenced about being close to the ground happen because it's in autoLand mode and getting really close. They happen every time an auto land is done.

 

[Futureroads]

I looked at this flight some. In summary, the Mavic behaved normally - there wasn't really an incident. During an RTH the Mavic (and the P3) will hover for about 3 or seconds after it gets to the homePoint coords. After that it begins it's descent. In this flight after the Mavic climbed to the RTH height and the pilot repeatedly applied full back throttle but would then release the throttle to the neutral position.
View attachment 3242
Each time the throttle was released the Mavic responded by starting to climb to the RTH height.
View attachment 3243
The Mavic actually switched to AutoLanding at time 147. The RC connection was broken at 153 and the Mavic started it's descent. In addition to the throttle input there were small aileron and rudder inputs that may have delayed the descent phase.

The entries in the eventLog stream that @f3honda4me referenced about being close to the ground happen because it's in autoLand mode and getting really close. They happen every time an auto land is done.

I really appreciate you taking the time to analyze this! I did apply full back throttle multiple times to try to get it to descend. I thought you could manually override the RTH at any time. I couldn't understand the movements it was making on its own when it changed altitude multiple times and flew toward home but suddenly hovered. What confused me most was why I had no manual control.

I guess what i have learned so far is even though I think its confused just take my hands off and assume it will be smart enough not to fall out of the sky no matter how it looks to me.

 

[BudWalker]

I really appreciate you taking the time to analyze this! I did apply full back throttle multiple times to try to get it to descend. I thought you could manually override the RTH at any time. I couldn't understand the movements it was making on its own when it changed altitude multiple times and flew toward home but suddenly hovered. What confused me most was why I had no manual control.

I guess what i have learned so far is even though I think its confused just take my hands off and assume it will be smart enough not to fall out of the sky no matter how it looks to me.

You did have manual control in that you overrode the RTH when back throttle was applied. It would descend some (7 meters), but, as soon as throttle went back to neutral the override stopped. The AC then resumed doing it's RTH and climbed back to RTH height. Take another look at the plots. You would've had to kept back throttle applied until it was on the ground. That might've been a little tricky. An easier way would've been to cancel RTH via the RC button or via the Go App.

 

[Andrew F]

I got my mavic a few days ago and when I was flying it in my city I only flew it around 2,500 feet away from home and I received a warning that my remote signal was low/lost. I was hoping to place my complete confidence in the mavic that something like this wouldn't happen within a 4 mile radius, to lose signal at such a low distance is startling, anyone know what's going on?

Wow. It's amazing how newbies think 2,500 feet is a "low distance."

 

[Futureroads]

You did have manual control in that you overrode the RTH when back throttle was applied. It would descend some (7 meters), but, as soon as throttle went back to neutral the override stopped. The AC then resumed doing it's RTH and climbed back to RTH height. Take another look at the plots. You would've had to kept back throttle applied until it was on the ground. That might've been a little tricky. An easier way would've been to cancel RTH via the RC button or via the Go App.

Thanks again for the help!

 

[ghostrider215]

I purchased antenna expanders from eBay and was wondering if that would improve some of the issues described on this thread? Losing signal at around 2000/2500 distance from controller? Also, I assume if I continue to fly further and lose complete controller, the Mavic will RTH correct? All the explanations make sense and 2000/2500 is still great distance but should would sure would be nice to be able to get a bit farther and closer to the "4km".

 

[Futureroads]

I also purchased a set of passive RF signal reflectors. I have no plans for flights that come anywhere near the stated 4 mile range of the Mavic but I heard these will provide as much as a 50% increase in signal strength and thought for the price they would be a good addition to my Mavic accessories.

 

[MyrtleManiac]

Sorry my mistake - incorrect terminology indeed. I should have said Pitch as it retains Pitch and Yaw in fact Have corrected my post accordingly. Last week I was flying over a field filming haymaking. Shot up to ~ 200' to capture the hay rake do the final run across the center of the paddock having passed off all of the RTH battery warnings. With tractor and hay rake converging on my spot at paddock centre to complete the job (and my movie) I got "Critical Battery - Landing" and down she came. Whilst contemplating the lack of vertical control and the thought of my Mavic ending up in a large round bale of hay it occurred to me to use the functioning controls I had left and flew it at least 200m home. Pretty much like an engine failure in a light aircraft really.

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That was a great piece of work and very well done under pressure! This is good to know if our when this happens to anyone else. Good flying!

Sent from my SM-G925P using MavicPilots mobile app

 

[ghostrider215]

I also purchased a set of passive RF signal reflectors. I have no plans for flights that come anywhere near the stated 4 mile range of the Mavic but I heard these will provide as much as a 50% increase in signal strength and thought for the price they would be a good addition to my Mavic accessories.

Same here but always nice to have better signal strength. I'll come back here and share if it improves since I know exactly where he signal weakens. Thanks!


Sent from my iPad using MavicPilots

 

[Andrew F]

Same here but always nice to have better signal strength. I'll come back here and share if it improves since I know exactly where he signal weakens. Thanks!


Sent from my iPad using MavicPilots

Cool. Please do. Before, after, before, after test would be awesome to try to eliminate other variables.