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Beyond Max altitude behavior

ihf

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The Tello has a maximum altitude of 30m. I was wondering what the Tello will do if it were to fly out the window of a building at a greater altitude (above the 10th floor or so). Does it descend in a controlled way to 30m (if that is the setting)?
 

MrSpok

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Does it descend in a controlled way to 30m
No. The altitude relates to the height of the start point.
You start at your floor so this is 0m. You fly out of the window (2m above your floor) at an outside hight of 20m. So you are 22m above the ground. For the Tello this are 2m.
The altitude is measured by the air pressure and it is not relevant wich hight above the ground you fly.
 

Ansia

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You can descend to negative altitude. It just won't let you fly higher than 30m from take off altitude if it makes sense to you.
First time I went negative, I panicked, because I didn't understand what was going on. Ohh the n00b ol' days!:ROFLMAO:
 
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volate!lo

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This is just my observations:
Measured (and displayed) altitude initially relates to takeoff point.
It seems to change a bit during a flight depending on what VPS sees, and what IR ground sensor and barometer are reporting.

You can trick Tello into higher altitude by flying from a house, or hill. I live on a hill and m office is on the top level of our house so how do I know...
But keep one thing in mind: VPS does calculations based on the movement it sees. If the ground is further away then it expects based on its sensors, the relative motion of the image does not match what it's internal algorithms expect. You are simply exceeding the design parameters and VPS may go completely mad.
I had this once and Tello did violent toilet bowls (just like if you go mad on the pitch & roll sticks). VPS position was wrong by 200m after that incident.
Even if VPS does not go mad completely it may not be able to hover by tself. So and loss of Wifi means Tello is gone.

If you fly over a cliff VPS goes completely mad, because it expects most of what it sees in the downfacing camera to be relatively flat ground. Instead when going over the edge all it sees is a vertical wall and its algorithms are not prepared for this. If you are lucky it switches off and you can bring it back in atti mode. If not Tello is gone.

You can fly below 0 altitude. Just keep in mind that Tello has a nice safety "feature" that reduces rates below a certain altitude. So while Tello is 10m high it may think its at 0m and significantly reduce rates, making it impossible to fight even lightest wind. Now how do you land tello if it is taken away by the lightest wind...
This however does not always happen. No clue what exactly triggers this, maybe Tello recognizes the discrepancy after a few moments and adjusts something internally (without changing the displayed altitude).

Overall: Its easily possible to trick Tello into higher altitudes but do so only if you don't care about a fly away. Anyone complaining about a flyaway after such a trick is a fool IMO.
 

Guorium

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I had flown over water and it just drifts because vps fails to see water and 3s of failure kicks it into atti mode (shouldn’t this be alti mode?) where it holds altitude u gotta control the horizontal drift manually. If tello drifts to land it will regain its steady hover. Can test this over a pool. I would expect this to happen when it is flying out of a cliff, because vps hates far surface for some reason.

@volate!lo if tello is far higher than starting height but it detects something close below it will enable speed limit too. They really did go all in on this “feature”.
 

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