Hi,  I posted a while ago about the problem with the Phantom 4 Pro that I’m having with the RTH and the drone ascending above the set RTH altitude. Well I did some testing and it looks like it is the “RTH obstacle avoidance” and the bright Sun making it climb. I did multiple RTH and when the Phantom was facing the sun it would keep ascending. I had it ascend to 200’ one time, almost 300’ another time and over 600’ before I canceled the RTH on another. I’m wondering if this is what is causing a lot of these lost aircraft on RTH?

Thanks
Dale



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Hi All, I know this has been reported but I havent seen it for awhile not sure whats happening with the  error. I sent an email to both DJI and Litchi

Phantom 4 Pro , Using Litchi  3.10.3 , RTH altitude set @ 98 feet, All firmware and software up to date.

  
  

I had a problem with RTH on at least two occasions. On 2-11-2017 I was at 126’ and pressed the return home button and the aircraft ascended to 751 before I cancelled the RTH. ( I was talking to someone and not paying attention to what the drone was doing) and before that on 2-10-17 I was at 92 feet and used the RTH button and the drone flew to 219 feet before I cancelled the RTH .

  
  

2017-02-11_07-51-32_v2.csv

  

12m 0.9s              P-GPS   18satellites         126.0ft  0.5mph 1,805.4ft              63%        12.919V                4.307V  4.304V                4.308V  0.004V  Go Home button pressed

  

13m 28.9s            Go Home             17satellites         751.0ft  6.3mph 1,775.7ft              57%        12.919V                4.307V                4.304V  4.308V  0.004V  RTH cancelled

  
  

2017-02-10_08-03-54_v2.csv

  

2m 1.3s Go Home             19satellites         92.0ft    0.9mph 122.7ft  93%        12.869V                4.285V  4.291V  4.293V                0.008V

  

2m 27.5s              P-GPS   19satellites         219.0ft  6.7mph 123.2ft  91%        12.869V                4.285V  4.291V  4.293V                0.008V  RTH cancelled

How about trying this to confirm that it is the sun? Do the RTH and if it kept ascending cancel than let it HOVER and then turn the AC facing the opposite direction and then start RTH again and let us know. Maybe you are onto something...

Dale, maybe that is the point, the strong sun will be considered as an obstacle.
The aircraft will climb if VPS detects any obstacles during RTH which does good to ensure the safety.
Please do not fly it facing the sun and check the performance again.

I wonder how high you have to climb to avoid the Sun?   ;-)

dronist Posted at 2017-2-20 12:37
How about trying this to confirm that it is the sun? Do the RTH and if it kept ascending cancel than let it HOVER and then turn the AC facing the opposite direction and then start RTH again and let us know. Maybe you are onto something...

I'll do some more experiments with some video and flight logs. But I did the RTH facing in the general direction of the sun and let the aircraft climb above the set altitude then I cancelled and turned the aircraft 90Deg and tried the RTH and it worked fine (a couple of times).  I then turned off the Avoid Obstacles while RTH and it did not ascend  just returned home because it was already above the RTH altitude.   

DJI Natalia Posted at 2017-2-21 04:08
Dale, maybe that is the point, the strong sun will be considered as an obstacle.
The aircraft will climb if VPS detects any obstacles during RTH which does good to ensure the safety.
Please do not fly it facing the sun and check the performance again.

The last I checked the Sun is pretty far away to be avoiding   . Joking aside if the aircraft performs an automatic return to home for some reason you don't have a chance to make sure it is not facing the sun. If the Home point is in the direction of the Sun that is the way the aircraft goes.

KM5RG-Robert Posted at 2017-2-21 06:59
I wonder how high you have to climb to avoid the Sun?   ;-)

to the MOOOOOOOOON....

DalecWilson Posted at 2017-2-21 17:05
The last I checked the Sun is pretty far away to be avoiding   . Joking aside if the aircraft performs an automatic return to home for some reason you don't have a chance to make sure it is not facing the sun. If the Home point is in the direction of the Sun that is the way the aircraft goes.

Then you are screeeewed...

But at least you found out that you can't fly during sunlight so I hope you don't live in ARIZONAAAAA  

It is a nice day tomorrow here, I will try it on mine and let you know...!

I suppose you would still have stick control and assuming you still have live video feed you can watch the altitude level and keep it low. Without live video yes it will go to the moon

KM5RG-Robert Posted at 2017-2-21 06:59
I wonder how high you have to climb to avoid the Sun?   ;-)

Till your props melt!!