hello everbody, I made a three flights last Sunday and I tried the dynamic home point option. In fact I didn't move from my point (about 10 meters from the takeoff point of my Inspire). After inspection of my flight log I saw that my dynamic home point was floating all the time from about 50 to 300 meters. Never it was on my original position. It happens for my 3 flights. The GPS from the quad was absolutely correct...... So be carefull if you use the dynamic home point and look on the map because if the failsafe is triggered you may have a bad surprise. I don't want to say that it is an issue but just be aware and test it. So if you have some ideas why this happens, you are welcome

had a similar situation and at 19% battery got a message saying low power, going home.    i was able to override with RC but at some point it wasn't possible to correct and it went into the trees heading to the wrong home point.  now i'm looking for spare props.   i had critical battery set at 10% so don't know why it headed home at 19%.  also did not try to cancel by pushing RTH as was fighting for control...suppose that was a critical error on my part

I'd like to hear from peoples if my observation is really an isolated problem or not. If there are more peoples (like magaspen) with this "Issue" then i think it would be a good idea to bring this to DJI....

By the way i ask myself if the integrated GPS in the RC controller also use both GPS/ Glonass positionning systems.

And the use of an iPad does it block the GPS receiver in the upper part of the RC?

Some questions i would like to have cleared.

Would be nice if Tahoe_Ed and some officials from Dji would give their opinion.

Thanks a lot

I brought this up in another post but my inspire had a simular problem after .17 update. I set my home point to my rc and took off  my but according to my flight log as soon as my bird left the ground my home point was changed to 1/4 mile away

I had a similar experience when I was running Android. The inflight,newly set,dynamic home point was off by 150 yards. I over rode the error and was able to manually land where it was supposed to land.

I haven't tried it again since I switched over to IOS app

ruddy951 Posted at 2015-3-11 20:20
I brought this up in another post but my inspire had a simular problem after .17 update. I set my ho ...

Just like me now.....

Did you have some official explanations from DJI ?

magaspen Posted at 2015-3-11 16:54
had a similar situation and at 19% battery got a message saying low power, going home.    i was able ...

The Inspire constantly calculates your flight time. So when you get close to a point, where it has battery only to go home, it will start automatic RTH. So far, I noticed, that it counts to the critical battery level, not the whole battery. So if you have critical level set for 15% and you need 20% of battery to get home with the bird, it will start RTH when it reaches 35% of the battery.

Skywolf007 Posted at 2015-3-11 21:39
The Inspire constantly calculates your flight time. So when you get close to a point, where it has ...

Skywolf,
Thank you!

This is very good information. I would hope this is the way it works. But, are you sure? Please excuse me for double checking. Have you pushed it to this point? Again, please don't take me wrong, because I'm most appreciative of your input on this. If it works like this and the operator over rides the failsafe RTH function for an instant with stick input, will it continue to go back to automatic RTH?

magaspen Posted at 2015-3-11 16:54
had a similar situation and at 19% battery got a message saying low power, going home.    i was able ...

Wow! We need to get this figured out!

rfrye Posted at 2015-3-11 21:49
Skywolf,
Thank you!

I pushed the bird to this point multiple times. Also this is my observation, and not official dji statement.

1st time is started automatic RTH I had like 70% of the battery, and the bird was like 2 KMs away, still shooting a video. You can override RTH by cancelling - you have 15 sec to do it, or switch P-A-P on the remote.

About RTH Critical battery level. I did this test a few times. I set different critical battery levels, and it seem the bird immediately starts RTH when the battery drops beyond the time needed to fly back+critical lvl.

I also noticed that the bird does not fly full speed when you engage RTH. It only descends 3m/s and the max fly speed is 10m/s. at least this is my observation so far.

I would really like to do some more test to confirm everything here, but its quite windy outside, and very cloudy. The next few days the forecast says it will rain. Saturday and sunday should be a nice weather so I will test it again, and put some screen shots here.

Skywolf007 Posted at 2015-3-11 21:39
The Inspire constantly calculates your flight time. So when you get close to a point, where it has ...

totaly agree and correct

Skywolf007 Posted at 2015-3-11 22:27
I would really like to do some more test to confirm everything here, but its quite windy outside, an ...

Thanks again Skywolf!!! This is GREAT information.

Thanks for your patience with me on this.

Keep us informed on your testing. I guess what I'm afraid of  (if it works like this) is unknowingly and inadvertently canceling the automatic RTH... when... it's actually trying to save my bird.

Skywolf007 Posted at 2015-3-11 22:19
I pushed the bird to this point multiple times. Also this is my observation, and not official dji  ...

Do you suspect it might select the slower best ascent and horizontal speeds on automatic, failsafe RTH to seek the most efficient battery usage? Kind of like setting up the best glide slope on an airplane when you have an engine out procedure...maybe? Are you a rated pilot?

Skywolf007 Posted at 2015-3-11 22:19
I pushed the bird to this point multiple times. Also this is my observation, and not official dji  ...

I quote '... RTH when battery drops beyond the needed to fly back+critical lvl.'

Imagine a windy day (20miles/30km). Wind comming from the north.
Flying south, testing automatic RTH.

Time to fly back won't be the same as flytime getting there.
So i hope the Critical Battery level of 10% will not be reached before return home.
If it is, well i can already see a premature landing but atleast one within LOS  
And you can't get out of this one.

Please correct me if i'm wrong.

Patrick,
Had the exact same experience you described under the same circumstances with Dynamic Home Point. I've had four flights, it occured once. Nothing bad happened.

This happens to me too. A little scary if it sets home point somewhere in a tree or something. Hope this gets fixed. Always wondered if the tablet blocks the GPS signal...but that would be quite a design flaw. Pretty much happens on every flight, so hopefully this gets fixed or we find out why it's happening.

cobcrate Posted at 2015-3-12 00:13
This happens to me too. A little scary if it sets home point somewhere in a tree or something. Hope  ...

Hi Cobcrate, Hi everybody,

i sent an e-mail to DJI support giving the same explications like in this tread. Hope they give me a response soon.
Keep you posted when i have some news.

Good flight

magaspen Posted at 2015-3-11 16:54
had a similar situation and at 19% battery got a message saying low power, going home.    i was able ...

Sounds like it headed home at 20% and hit critical at 10% automatically landing at that position .

That's all good and we'll but why would my bird change its home point  on a 95% battery

Pushing the limits of the safe flight / battery % at 20% , this is funny why you would take your 3000.00 plus camera platform to extreme low battery could be a huge mistake ... Wow even when I'm not flying out over water I watch that battery % like a hawk ! 40% is my time to start looking at my distance vs return home ability , then I can make my own adjustment and action accordingly , if you think your inspire is going to always return or somthing on its own under some false safety mode at 20% you could be very disappointed ... Inspire or phantom , watch you battery levels folks. Don't rely on auto safety features , be the safety feature pilot aware !

Skywolf007 Posted at 2015-3-11 21:39
The Inspire constantly calculates your flight time. So when you get close to a point, where it has ...

In a perfect world maybe . Did you fly hard or down wind chewing up battery , the inspire won't be taking into consideration flying back against the wind and will suc up battery juice you'll be sorry relying solely on safty rth features ,low batt RTH works but then pushing the limits doesn't always work the way you think in the field.

dundee Posted at 2015-3-11 23:33
I quote '... RTH when battery drops beyond the needed to fly back+critical lvl.'

Imagine a windy  ...

Absolutly correctomundo ! Always keep Yer one eye on your battery % , thinking the inspire will simply save itself in any situation will be a sad mistake , or simply pushing the limits just to see .... With $3000.00 bucks of camera platform equipment seems really foolish or something ???

I am a little bit disappointed about the fact that the most peoples here on the forum don't read the topic and the reason why I opened up a tread.
First: I never asked something about return to home with critical battery level.
Second: I asked if somebody had the same situation with jumping and moving Dynamic home point
Third: I asked if you think if it's an issue and we should report to DJI
Fourth: in case of an urgency a moving home point can be disastrous (read first post). Meanwhile I agree that the return to home function should not be used just because you want to break a distance record or your use of the craft is pushing it to the limits

Fifth: please try to post your comments in the treads they are concerned

Thanks for some constructive ideas regarding to the first question in the tread and thanks for the peoples who shared their experiences


Good flight and keep on the safe side

i got a replacement inspire recently and have tried to test the return to home and the first time it just tried to land where it was.
i have seen this twice and so far i think the home point is not even setting initially. i will do tests when i get  a chance. i have tried to set a dynamic home point once and that did not work correctly either. i did use the features with pretty good success on my last bird. i am guessing it is firmware related. i will post my test results when i can.

Staying off topic here, I wonder what the optimum airspeed / throttle is? ...... Back to original topic

Could it replicated?
Did you upload the record?
I can not sync any record from your account.

DJI-Autumn Posted at 2015-3-19 16:58
Could it replicated?
Did you upload the record?
I can not sync any record from your account.

Hy DJI-Autumn,

Thanks for your fast reply, i'm not at home but i will send my flight Logs this evening after work.

Thank you for your great support ( 1900 middle europeen time)

patou72 Posted at 2015-3-19 19:08
Hy DJI-Autumn,

Thanks for your fast reply, i'm not at home but i will send my flight Logs this eve ...

In current iOS app, the home point is based on either RC's GPS or mobile device's GPS.
When RC's GPS signal is weak, the home point will based on your ipad's GPS, so it may lead to a moving point because of the less accuracy of mobile device's GPS.
It will be optimized in next iOS version.

DJI-Autumn Posted at 2015-3-19 19:52
In current iOS app, the home point is based on either RC's GPS or mobile device's GPS.
When RC's G ...

Thanks, that's all i need to know.

great work Dji-Autumn

DJI-Autumn Posted at 2015-3-19 19:52
In current iOS app, the home point is based on either RC's GPS or mobile device's GPS.
When RC's G ...

Maybe it would be a good idea for the beginners to inform them....it could be taken as a fly away (when they trigger the return to home button) from a lot of peoples.

DJI-Autumn Posted at 2015-3-19 16:58
Could it replicated?
Did you upload the record?
I can not sync any record from your account.

Hello Dji-Autumn,

I just uploaded the flight logs. Take a look on the 3flights I did on the 08.03.2015. There you have some good examples.

Hope you can use this informations

Thank you

patou72 Posted at 2015-3-20 06:20
Hello Dji-Autumn,

I just uploaded the flight logs. Take a look on the 3flights I did on the 08.03 ...

Thanks for this.

It's very valuable.

Skywolf007 Posted at 2015-3-11 21:39
The Inspire constantly calculates your flight time. So when you get close to a point, where it has ...

in my case it was almost overhead at about 300 feet when it headed home with 19% battery.  doesn't seem reasonable that it should need that much battery to descend from 300 feet almost straight down (but then the home point had moved several hundred feet)

DJI-Autumn: quoted:  
In current iOS app, the home point is based on either RC's GPS or mobile device's GPS.
When RC's GPS signal is weak, the home point will based on your ipad's GPS, so it may lead to a moving point because of the less accuracy of mobile device's GPS.
It will be optimized in next iOS version.

So then I should not place my iPad Mini 2 in airplane mode which then will shut off the iPad mini's gps?

Is this on the latest firmware? At least you get the dot to show up on flight log.. I did before latest firmware... Not anymore.. I have had this same issue as well.... I have a couple threads and videos on it: http://forum.dji.com/forum.php?mod=viewthread&tid=10933&page=2&lang=en
http://youtu.be/Ia_sjREFyfo
http://youtu.be/vVuBLwkGCbU


Now the issue I have is that I cannot even set RC dynamic home point Period... And before I was able to see it on flight log... Now even though it shows while flying it is just simply gone on flight log playback..

Genettico:
I am using the latest firmware, my mini iPad 2 has wifi off ( wouldn't matter anyway since I am outside with no wifi network), and has no cell service enabled either.  My last there flights at the baseball field mainly showed the home point in green.  The RC signal did not appear but a few times as that large blue Dot, which will move if you move your location. Basically was not there either.  
Next time I fly I will press the dynamic home point on the iPad and see if it marks it,  then I will press RTH button on the RC and see where the I1 lands near, either the initial home point logged in or my position (the RC ).   I will make sure I am at least 30 feet away from the original home point recorded on takeoff.
The Inspire should land closer to me since the RC is the new RTH landing area(dynamic home Point)   Correct?

I Just remembered, the last three flights at the baseball field, I did not press (set) the dynamic home point, so maybe thats why it was not marked on the flight playback?  Only the initial home point, as indicated with a H on a green circle, was present on the flight playbacks cause I never pressed the dynamic home point button.  

dentin11 Posted at 2015-4-20 12:24
Genettico:
I am using the latest firmware, my mini iPad 2 has wifi off ( wouldn't matter anyway sinc ...

Correct... Even if you are not near a network, the WIFI being off and cellular being off but ipad not on airplane mode allows for better location services...

Also, the home point on playback shows the initially recorded homepoint... If you successfully set the new homepoint dinamically via RC or Bird, it will show the change (during flightlog  playback)from the automatically set, to the one you set dinamically. I have confirmed this for both. However, after the firmware update I cannot set dynamic  Homepoint to RC... Only to BIRD.

Hey Patou72 and all, so I guess we should only use the home point, green circle with H, that is auto set at take off till there is a solution?
since dynamic home point is not reliable and we want the RTH or failsafe to be accurate.