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Litchi not pointing at POI

Discussion in 'Pro/Adv Discussion' started by Steve_in_NJ, Jul 9, 2016.

  1. Steve_in_NJ

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    I did a mission today that involved circling a house. It had a POI right on it. The video showed the house nowhere near the center of the frame as I would have expected. See the POI placement. The house is shown at the very bottom of the frame in the 2nd picture. The house stayed at the bottom of the frame throughout the two trips around it. What's going on here?

    [​IMG]

    [​IMG]
     
  2. alokbhargava

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    What was the height of the POI? Setting correct POI needs its location and height.
     
  3. Steve_in_NJ

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    3 feet. The craft was at 220 feet.
     
  4. impilot51

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    Were you still within connection distance? If not, you won't get gimbal elevation control.


    Sent from my iPad using PhantomPilots mobile app
     
  5. Steve_in_NJ

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    Really? No I was not connected at that point. The craft was on it's own. Why would it not have gimbal elevation control? It certainly "hit its marks" perfectly in terms of position and heading at every point, circling and pointing in the direction of the POI. The gimbal pitch, set at "focus POI" was listed as being -45 or -50 degrees - why on earth did it NOT do that?

    BTW I just examined the very end of the mission. Another 3 foot elevation POI was parked squarely on the house that was just 40 feet from the end/landing point, where I was standing. The camera did NOT point at the POI there either. The gimbal pitch was listed as -70 degrees, but the camera barely pointed down. I was of course connected to the craft at that point.
     
  6. impilot51

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    From the help section of Waypoint flying on the Litchi web site.
    Litchi.jpg
    Thats why. Because for whatever reason, when outside of controller range, Litchi is no longer able to control gimbal angle. I have tested this myself and confirmed it. When you loose RC control, the gimbal will stay at whatever angle it is set at. There is a way around this though, but you must you straight line rather than curved waypoints. You can set a waypoint action to set the gimbal at a particular angle. Problem is, it will stay at that angle until the next waypoint is reached, with a new angle setting.

    Bottom line, to get that nice POI framing you need to be in RC contact.
     
  7. Steve_in_NJ

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    Well that's that, I guess. This all leads me to ask WHY? Why is it so? All the other parameters of a trip can be executed no problem when out of contact - WHY NOT the gimbal pitch? What makes it "different" ? I really believe that this boils down to a programming issue for the Litchi developers; they need to sort it out and make it happen.

    Actually thinking about it, I guess that gimbal control IS different from all the other parameters that Litchi controls. Altitude, speed, location, heading...these are all things that litchi directs the PHANTOM to do, not the gimbal. But seeing as Litchi can adjust the gimbal during "no curved waypoints" missions, I don't get why it can't do it all the time.

    I want it all, and I want it right now!
     
    #7 Steve_in_NJ, Jul 11, 2016
    Last edited: Jul 11, 2016
  8. Pharm

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    The DJI SDK only allows gimbal control if the AC is in contact with the RC. This "restriction", if you will, limits what Litchi is allowed to do. It's a DJI limitation, not a Litchi one. DJI will have to support it in their SDK and, according to Litchi, it has been suggested to them.
     
    #8 Pharm, Jul 15, 2016
    Last edited: Jul 15, 2016
    mikesmiley likes this.
  9. Pharm

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    OR just set a specific gimbal angle and continue to use a curved path. Just make sure you have a good guess on the correct angle (or do your trig homework). When I fly a long range sightseeing mission, I use a curved path but set my gimbal to -30 degrees. It stays there the entire flight.
     
  10. Steve_in_NJ

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    Thanks for that - I have been thinking the same thing. I may have to do a quick spin around to see what -30 degrees looks like.
     
  11. Pharm

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    I forgot to mention, that's when flying at 350 ft.