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Survived crash but want advice

Discussion in 'Standard/4k Discussion' started by droney1, Aug 27, 2016.

  1. droney1

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    On my 3rd day of ownership of a Phantom 3 Standard and had a crash today. Every time I had been going out over the last few days I had done a calibration beforehand but this time I didn't (from what I read, you don't need to do it every time unless you're in a vastly different area).

    After taking off and flying for 2 mins, dji go was reporting compass error and I noticed the drone flying away. I immediately descended but it was still moving horizontally. I assume it was only wind moving it away and the drone would have remained idle if no wind, in this position? At this point, I was panicking and wanted to take it down as safely as possible. In hindsight, I could have used the camera feed to try and manually steer back, but panic prevented this.

    I ran after the drone and just when I saw it about to hit an object, I used the remote to descend it to the ground and the drone tumbled over. I then dropped the remote and ran over to it, it was still powered up and whilst holding the drone, I could not power it off. I tried clicking twice on the battery and then a long press and it failed to power down the motors. I eventually had to rip the battery out to finally stop it.

    So..... I guess the biggest lesson I need to achieve is learning how to steer the drone manually in the event the gps fails? I really did not expect the GPS to be lost so easily.

    Next, I don't know why the drone didn't shut off when 1. it crashed and 2. I tried to turn it off via the drone battery button. Is there anything I could have done to shut it off?

    Also, I don't know why the device had a compass error at all. I was flying on a big football field which I didn't anticipate would have much interference... and I had probably 10 gps satellites listed when I took off. I am also running latest firmware.

    As for the P3S... I broke a propeller blade but otherwise the drone seems to work fine.


    Lastly, any tips on how to get the logs from this flight? Will I be able to diagnose much about what happened?
     
  2. Mark The Droner

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    Yes - panic is almost always the worst thing you can do.

    I don't know why your compass went bad unless your previous calibration was bad. You always want to do a calibration away from metal including buried metal. You should not have your cell phone in your pocket or your car keys during compass calibration.

    You're saying the motors were still spinning while it was on the ground? You need to hold the left stick down for 2-3 secs while the craft is on the ground for the motors to quit. Another option is to CSC to quit the motors, but left stick down is very much preferred and CSC should be a last resort. If it's upside down, it may behave oddly.

    In your panic, you probably didn't shut the battery off correctly. You probably didn't hold the button in long enough on the second push.
     
  3. droney1

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    Thanks for the comments. In regards to the motors, I guess this was just bad luck. I am aware of how to land gracefully but at the time, I was trying to get it on the ground as soon as possible to prevent it hitting something bad or a person. In the rush, I push the left stick down enough for the drone to touch the ground (and then I dropped the remote and ran after the drone) but because I was coming in with such speed and on an angle, it had no hope of gracefully shutting down. I guess in hindsight, I could have put the left stick in to a locked down position and then ran after it, as this would have eventually stopped the motors?

    I am assuming the left stick down purely just slows the propellers until the drone eventually comes down? It isn't smart enough to take in to account altitude or anything?

    And ok. That sounds plausible if I was in a panic. But I certainly thought I pressed it twice and then held it down for a few seconds, like how I have turned it off before over... 7 or so flights.
     
  4. Mark The Droner

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    Left stick down during flight will cause the drone to lose altitude but it's programmed not to drop too fast. When it stops losing altitude, it assumes it has landed and the props stop after a few secs. No, the props will not stop while in the air.

    Welcome to the site!
     
  5. RodPad

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  6. Pharm

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    The way to turn the bird off is the same way you turn it off every time you land. Left stick locked down. Sounds like, after the error that it switched to Atti mode. I guess you panicked but you should have just flown it back to you. Did you by any chance, take off near the metal goal post or a metal fence? That will cause a compass error even if you didn't calibrate near them. The only time I've ever gotten a compass error was when I took off from a metal dock. I hadn't calibrated recently. I knew it was risky but did it anyway. As soon as I got the compass error and it auto-switched to Atti mode, I flew it back and had my wife hand catch it off the dock. This was made easier because I was aware of it's orientation and knew which direction to fly. The video is funny. Every time she'd be inches from grabbing it, it would drift just out of reach. She kept sneering at me because she thought I was doing it on purpose just to aggravate her. She finally grabbed it without falling in the water. .
     
  7. Neon Euc

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    If that happens again the first thing you need to do is trigger the "return to home" function... And if there is obstacles in the way... Just press up on the joy stick... It will still return to home but you can still adjust the height so it won't bump into things

    Sent from my Power using PhantomPilots mobile app
     
  8. droney1

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    Return to home would work??? Don't know how that would work without compass.
     
  9. jeganx

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    What mode were you in when the drone start having compass error? P-GPS or ATTI? It's just like what everyone above said. You should switch to ATTI and fly manually (meaning it wont hold steady if there is a wind. So you have to control to offset the wind.) Turning off the motor is simply use descend (normally its left stick down if its in controller mode 2, I use mode 3 so right stick down).
     
  10. BudWalker

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    A compass error means there is a good chance the P3 doesn't know it's heading. Initiating an RTH will cause the P3 to fly in the wrong direction.
     
    #10 BudWalker, Aug 28, 2016
    Last edited: Aug 28, 2016
    Dirty Bird likes this.
  11. RodPad

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    What is funny, as sophisticated these are It should only need GPS to return to the starting point.
    If it is trying to go back to home, and GPS shows it getting farther away then it could turn say 15 degrees and try again, the future will be the answer.

    It surprised me that it even had a compass in it and then I found out it had a barometer?
    What, GPS will calculate elevation also. But of coarse, what happens when GPS is lost. It needs a back up plan.
    :D

    Rod
     
  12. BudWalker

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    The thread Does RTH work with Compass Error? talked about this very issue. It's a huge thread, and turns into quite the snarkfest.

    I'm not a DJI engineer writing FC code so I don't actually know. But, my personal opinion is that the P3 will start doing the successive GPS update type of navigation. But, only after it sees that using the IMU FC info isn't cutting it. I've looked at flights where this seems to be happening. Here's one if you're interested. Standard - Insight on my Fly Away? - HealthyDrone & YT Link
     
  13. RodPad

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    Yeah, I must have been through that one in May, none of the posts where new, I have to look at it again when I am having trouble sleeping. :)

    Yes, I remember your thread, once I looked at it.

    I will have to look through it also.

    Rod