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Litchi autonomous flight: lost my bird

Discussion in 'Pro/Adv Discussion' started by diveguy, Feb 5, 2016.

  1. diveguy

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    I purchased the Litchi app and practiced with it at a local field, then this evening took it for it's first official autonomous flight.

    I planned the course using the Litchi Mission Hub, checked and double checked the altitudes and path, and had it set for a 14-minute loop flight (according to the mission hub) to leave plenty of room for the battery. I was climbing up a fairly big hill (800 feet total climb) so I was very careful to set it to 200 feet above ground level for each waypoint.

    It look off and it went off on the mission. About 1/2 of the way out it lose signal, which wasn't completely unexpected but still unnerving. 10 minutes after losing signal it still wasn't back, so I feared the worst.

    I began to hike up the trail to look for it, and to my relief saw it coming back overhead. I ran back down the hill to the takeoff point (and final mission waypoint) and saw the bird overfly the waypoint by a significant distance of probably 200 yards. I had my remote turned on the whole time, but Litchi still said disconnected, even though it was relatively close. I tried closing and reopening Litchi, the remote, and even tried DJI GO. I was unable to get a signal and soon the bird disappeared from the sky.

    At this point it had been in the air more than 20 minutes, so I'm assuming it ran out of battery and auto-landed. Unfortunately it is in a very heavily wooded hillside with no access, so I'm afraid it's a goner. I just can't figure out why it overflew the final waypoint by so far and why I couldn't re-establish communication with it.

    At this point I'm afraid its a total loss but thought I'd share and perhaps someone else can offer some insight, and perhaps where the best deal is on a new one.
     
    #1 diveguy, Feb 5, 2016
    Last edited: Feb 6, 2016
  2. shockwave199

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    Sorry to hear this. What version of the app, Android or ios? What rev firmware of the app? I may be way off base with this but I don't really trust creating missions in hub, nor do I trust tweaking missions created in the app within hub. Hub for me remains buggy and glitchy to use. I only trust creating my missions in the app. So far so good, but I'm still on ios version 1.10. It's working well and since it's autonomous software I'm even more cautious about updating right away, until many reports are in.
     
  3. With The Birds

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    There must have been something wrong with your mission waypoints otherwise it would have come back to the last waypoint as planned connection or not.

    Have a good look at the waypoints again. May give you a clue where to look.
     
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  4. shockwave199

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    I have nothing to suggest that hub was the issue. I only have my own experience with hub, in that it remains glitchy. The more likely issue is the disconnect of everything that you experienced. What firmware are you at on your phantom? Were there compass or satellite issues? I'm assuming you have 1.21 for litchi.
     
  5. NoOne

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    Will it go back under normal control if you flip the switch from F to P? I just signed up for the beta testing of both Litchi and Autopilot and posts like this have me rethinking this!
     
  6. Erroll

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    I agree with this. One problem with the mission planner app is that if you accidentally touch the screen hard enough, the app registers a waypoint where you touched, and you often don't even notice the new 'waypoint'.

    Also double check your setting for "action when mission completed".
     
  7. shockwave199

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    That's a point. In a panic and seeing the bird flying back overhead I would have flipped back in p mode. Every second of an autonomous mission, my finger never leaves the mode switch. That could have helped saved a bad situation.
     
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  8. Sinisalo

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    it is probably irrelevant in this case but I just wanted to point out that the failsafe RTH does not work in 3rd party apps when the controller loses connection, it is a bug recently discovered by Autoflightlogic (Autopilot app) and wont be fixed until DJI updates their firmware.

    Home - Autoflight Logic
     
  9. With The Birds

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    Diveguy im sorry you lost your bird, i hate reading these stories and like happy endings. If set to mission complete on signal loss it should have been heading to last waypoint. If you can get back to the mission plan their should be a clue. If it was set to return home on mission complete it might be that the homepoint didnt record properly. Can you get the log of your tx up to the point where signal was lost?
     
  10. shockwave199

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    I have requested a lock button but doubt it'll ever happen. A simple lock button in the app so nothing new can be registered during examining a finished mission, or whenever you want to avoid setting a waypoint or poi by mistake.
     
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  11. With The Birds

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    According to
    Autoflight logic has said the issue with the current sdk is likely unique to their siftware as they implement a custom flight controller. They didnt say it is an issue in other third party apps.
     
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  12. Erroll

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    I agree 100%. A lock button would be ideal.
     
  13. Sinisalo

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    Yes they certainly did say it was a problem with ALL 3rd party apps. Autoflightlogic.png
     
  14. diveguy

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    Thanks All!

    I really tried everything once I saw it back overhead and could not get in control. I turned off the remote, then back on, tried different flight modes, relaunched Litchi and tried to get contact with DJI Go. In every case I saw the "Disconnected" message.

    I did have it set to land at the end of the mission, as well as having the final waypoint about 20 feet from the takeoff point. Here's a look: http://bit.ly/1USAuaO (Note that my next waypoint is 368 feet up, but I was always within 200 feet above the ground on the flight).

    Once the signal was lost early in the mission, I never got it back and that's something that never has happened before. I do know that it completed most the waypoints though because it came near the landing site before overshooting it. In the past, I've had the usual moments of being disconnected or losing video, but it's always come back up. I also tested the Return to Home function quite a bit when I first got it, 40 or so flights ago. It also didn't work this time (but of course the remove wasn't communicating with the bird at the time, so that makes sense).
     
    #14 diveguy, Feb 6, 2016
    Last edited: Feb 6, 2016
  15. With The Birds

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    Yes, I read the autopilot announcement.

    I also read the clarification they posted on this forum "
    To be clear, this ONLY affects third party apps if they use this one very specific API. This API can be thought of as "bare-metal", and it used by Autopilot because we have our own custom flight controller. There are other, higher level APIs which are not affected by the firmware issue, and if other apps use only use those APIs, they should not be affected".

    If litchi is using a higher level API in the SDK no issue.

    Other users have reported litchi isn't affected.
     
    #15 With The Birds, Feb 6, 2016
    Last edited: Feb 6, 2016
  16. Sinisalo

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    So unless an app developer comes out and says that their app is not affected by this bug, I wouldn't trust it either way. And for the sake of clarification, it says if they only use the higher level api
    RTH may not work with third party apps
     
  17. John Locke

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    Autopilot is supposed to trigger rth when the signal is lost, but it's broke, a bug in the sdk. Litchi is not supposed to trigger rth with signal loss, an autonomous feature in Litchi, it's supposed to continue the programmed mission. So logically the bug can't affect Litchi, and I believe Litchi has stated this.
     
    #17 John Locke, Feb 6, 2016
    Last edited: Feb 6, 2016
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  18. With The Birds

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    Ok.... So don't use it. Please don't confuse the OP in trying to diagnose his issue here- hopefully he can find his aircraft.

    One of the differences between Litchi and Autopilot, and of importance here, if you loose signal in a Litchi mission it will continue its mission until the last waypoint (the mission is uploaded at the start) Including return to home if set as the completion action.

    Autopilot constantly sends mission data to the aircraft during the mission. Currently loss of signal will see the aircraft stop and hover until either connection is re-established or critical battery level reached triggering a RTH.
     
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  19. shockwave199

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    This has been discussed at length in the original critical error thread. Litchi waypoints are not affected, but follow and focus mode can be.
    This makes me uneasy about the current rev of ios for sure. What firmware is on your phantom? Litchi support has said it's best to be at 1.6 which I am at and have not had problems yet at litchi 1.10. Also what firmware is you ipad on? I have stayed at 9.1 for quite a while now.
     
  20. AirSpace2016

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    This sounds very odd. From my own flights using litchi it has returned to the final way point but I never set to autoland always to hover. Not tried it out of signal range. Was the home point defo recoded to the slot you were at. I also noticed a dynamic home point setting. Its strange how it could not connect at all did you try unplugging the cable and plugging back in?