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Return to home accuracy?

Discussion in 'Pro/Adv Discussion' started by Djw93, Jan 27, 2016.

  1. Djw93

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    I have activated return to home a couple of times and have noticed sometimes when the quad gets within 20 meters or so it starts to land. Sometimes it has been over a tree or potential crash hazard. How close to the takeoff point is it supposed to land?


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  2. msinger

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    Your Phantom will land at its current location if not more than 20 meters from the home point. That's as designed.
     
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  3. Djw93

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    If it is activated from over 20m will it land any closer to the home point?


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  4. Meta4

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    The accuracy of RTH is the same accuracy as consumer GPS .. it should be within 2 metres most of the time.
    But there's no reason to leave ypur Phantom to RTH all the way home and autoland.
    You can choose a landing place much better than a blind piece of programming.
    Cancel RTH and bring it in yourself.
     
  5. happydays

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    If you're further out than 20m, the phantom will rise to your pre-selected RTH height (unless it's already above this height; then it will just stay at that altitude), return to the home point, pause for a few seconds and then begin a descent. It's fairly accurate. Go and test it for yourself.
     
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  6. msinger

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    Increasing or decreasing the distance from the home point will not improve or degrade the accuracy of the RTH feature. Since GPS is not 100% accurate, it would best best to choose a home point that has about 10 feet of clear space around it. That'll allow your Phantom to still land safely if it's a few feet away from the home point when landing.
     
  7. Djw93

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    I usually land myself, or hand catch. I was curious because it is a bit worrying if it did need to land itself because of remote failure that it may still land on a tree or obstacle near by. Some of the locations I fly at do not have a large takeoff area, such as lookouts on the mountain ranges I live near, I may only have a takeoff area with a radius of 5-10meters if the phantom tries to land itself 10meters from its takeoff point it may very well be off the edge of a cliff face.
    [​IMG]

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    #7 Djw93, Jan 27, 2016
    Last edited: Jan 27, 2016
  8. msinger

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    That should not happen. GPS is generally far more accurate than that.
     
  9. spindrift

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    I have a $10,000 gps for work that has only 2 meter accuracy without base station. If the P3 can land anywhere within 10 meters on rth, I'm happy.
     
  10. Meta4

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    Test it a bit more in an open area and I think you'll find it is going to be a lot closer than 10 metres.
    Most times it's going to be 2 metres or less.
     
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  11. mcphipps

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    Agreed. It is much better to take over the controls when you get it close to Home. I never let it land by itself like that. 20 meters is 60 feet. It won't land in the exact spot you took off from. I have came close, but never exact, but I always take control before it touches the ground. Could be a lot of obstructions in that 60 feet. Have fun.
     
  12. Mako79

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    Like @happydays said, the P3 is dead accurate on RTH. Try it out.

    The 60ft/20m is a safe guard for RTH. Its a redundancy on redundancy for those who don't understand why.

    DJI implemented this because previous P2 users were accidently triggering off RTH without realising and this caused mass hysteria. Many treated them as flyaways.
    An example was when P2 users were draining battery or landing and leaving the props running till it went into 2nd critical battery stage. If you had RTH + 30m ascend, and it was in your garage, your P2 would have bounced off your ceiling. Another story was when a user was testing carbon props and accidently dropped the controller and the battery flung out. He ended up with stitches and a broken toe.

    DJI also assumed that if you were within 60ft/20m, then you should have visual range and able to land or manoeuvre it safely.
    They also didn't want the P3 to waste more battery by rising 30m, then moving to home point, and descending. Doing this meant there higher chance of P3's dropping from the skies.
     
  13. mcphipps

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    If you have a remote failure you are kinda stuck with wherever it lands anyway. Awesome picture by the way.