Welcome to PhantomPilots.com

Sign up for a weekly email of the latest drone news & information

Preventing & Recovering a Phantom from a fly away

Discussion in 'Phantom 2 Vision Discussion' started by BenDronePilot, Dec 18, 2013.

  1. BenDronePilot

    Joined:
    Dec 7, 2013
    Messages:
    1,204
    Likes Received:
    131
    Here are some top tips on how to recover your Phantom should you experience a fly away. I also list some tips and precautions you can take to ensure your Phantom 2 is as reliable as can be and to minimize the chance of a fly away.

    So you're flying your P2V on a nice or not so nice day. enjoying your flight and suddenly the worst happens. It begins to do things it's not supposed to do and or takes off on its own. Following these helpful tips should set you straight.

    1) Take a deep breath

    2) Don't panic

    3) If it begins to fly away you can panic now. (just kidding) please refer back to steps one and two.

    4) If you have Naza mode enabled and your bird begins flying erratically that could be a GPS lock and or a compass problem. Switch to Atti mode to help stabilize your plane and bring it back IMMEDIATELY to land.

    5) Even if Atti mode isn't available but you see your bird behaving in any other way that feels out of the "norm" for you then immediately fly your bird back, if you have control. Even if your bird is far away, just land it wherever you can in a safe place and walk to it.

    6) Your Phantom 2 Vision will keep a log of it's last known GPS position as long as you have stable wifi. Keep the flat base of the Wifi range extender pointed as directly as possible towards your Phantom to Maintain WiFi and thus GPS location within the DJI app. Also make sure your transmitters antenna is pointed straight up and not sideways as seen in many peoples videos.

    7) Reference how much battery life is remaining before the crash so you can have an idea of how far it may travel should it be in the process of flying away from you. Also note the Radar screen of where it's current position is relative to you, should you not have an actual Visual of your Phantom. Again making sure to try to keep your Wifi repeater pointing in it's direction to maintain connection as long as possible.

    8) Turn off transmitter as last resort to activate the failsafe return to home function. Keep in mind that if you're below 66 feet when hitting RTH and their are obstacles between you and your Phantom that your Phantom WILL run into said obstacles as by default it flys in a straight line above the home position before descending.

    Your bird is on the ground now. Steps for recovering a downed Phantom once you believe it's on the ground. It is of vital importance you begin your search IMMEDIATELY to take advantage of certain features of your Phantom that you can use as a means to locate it.

    1) If you had a Visual of your Phantom as it reached the ground run to it immediately.

    2) call some friends to help you search.

    3) If you didn't have visual range but had a Wifi connection, refer to the last known position within the DJI app and go to that location as a starting point for your search. On full charge I believe the range of the Phantom is around 10 miles give or take.

    4) Provided you've not lost power to the Vision Camera in your fly away or crash event, you can take advantage of the Visions Wifi connection as a means to track it from greater distance. It would also have been helpful if the vision's Wifi itself wasn't hidden as it would make this process a bit easier. But what you will do is circle the perimeter of the last known location and cycle the power on the Wifi repeater from time to time, then try to make a connection to your Phantom. Keep doing this at set intervals and with the Wifi repeater antenna pointing in different directions. Wait about 30 seconds to a minute after each power up and then try to connect with your smart phone. If you make the connection it's a simple matter to find your Phantom by using the Find you Phantom function in the app.

    5) Continue searching in a grid pattern, fanning out if you have more than one person looking. You should be constantly trying to regain a wifi connection as you do this. Also ask any bystanders if they saw your Phantom flying and or landing anywhere.

    Additional things you can add to your Phantom to aid in a recovery should you loose your bird.

    1) Use a label maker and print your Name and Number and affix it to the Phantom. Add reward if found, if you feel it's appropriate.

    2) You can add a cell phone based GPS tracker. They come in many sizes, makes and models. They use GPS for location data and Cellular service for internet access to the device so you can find the location by searching an internet web site associated with the device. Price plans for these devices can be as little as $10 a month or upwards of $30 a month, not including the cost of the cellular service. I'd suggest using a pre paid plan for the cellular portion.

    3) A relatively free way you can use Cell GPS tracking. Get a second phone that supports cellular based GPS tracking. You can do this with android phones and the right apps like Trustgo though I don't know how reliable those are. I highly recommend going with an older iPhone such as a 3G or 3GS using the "Find my iPhone" function. If you have a GSM based cell service all you'd have to do is pop your SIM card into the phone you'll be using for tracking. And have the phone attached with velcro to your Phantom. That way you can have cell tracking without having to pay additional monthly or yearly service plan costs. Just the initial cost of a second phone for the use of tracking.

    4) Add a "clapper" like device to your Phantom that can cycle the power on something or create a horn effect. That may help you in your search should you not have a visual and you can't attain wifi connection to your Phantom.

    5) Consider adding a TP-Link 9 or 14dDB high gain antenna to your built in repeater to extend your Wifi FPV range to the DJI app.

    Steps to take to minimize a fly away from happening at all.

    1) Update all Firmware on both your Phantom and the Transmitter before you fly.

    2) Calibrate your Phantom's compass before your initial flight in an open field away from metal or power lines or concrete floors to get the best possible calibration

    Watch this great video from DJI's CIO Colin Guinn on calibrating your Compass for first flight as well as flight basics.
    http://www.youtube.com/watch?feature=pl ... osbWTHLfQQ

    3) Do not calibrate your compass before every flight, this is not necessary and may actually increase your chance of having a problem.

    4) Make sure all of your batteries are charged. (silly, but some may forget :p )

    5) Try to avoid flying near cell towers, over head power lines or areas were you believe their may be heavy interference from other 2.4 and or 5 ghz signals.

    6) Make sure your S1 and S2 three way toggle switches are both in the UP position.

    7) Before you take off make sure your Phantom has a good GPS lock. After power on the tail lights of your Phantom will quickly flash green then followed by a slow blinking green. This means you have marked your GPS home location. BUT it doesn't mean you will still have a solid GPS signal as sometimes you may need to let your bird sit for another minute.

    8) Reference your DJI app on your device. Make sure that you maintain GPS satellite lock of the Minimum 6 satellites or more for at least about a minute to be on the "safe" side. I've seen the satellite lock drop in and out sometimes until finally it staying stable. If you take off while your signal is dropping off and on you may experience erratic flight behavior.

    That's mainly it for now. If anyone would like to add to this please feel free. Good luck and safe flying!
     
  2. BenDronePilot

    Joined:
    Dec 7, 2013
    Messages:
    1,204
    Likes Received:
    131
    Re: Preventing & Recovering a lost Phantom from a fly away

    You're very welcome. I know how bad I'd feel if I lost mine and anything I can do to help others either prevent a lost Phantom from happening to begin with and or find their lost Phantom is worth the time and effort.
     
  3. Noël

    Noël Guest

    Re: Preventing & Recovering a lost Phantom from a fly away

    Here is a small demo video.
    It's not a Vision, but still very educative!

    How to control a DJI NAZA flyaway.
    http://www.youtube.com/watch?v=iW0hqzixwsk
    (it has been posted on this forum before)
     
  4. coloradosky

    Joined:
    Nov 10, 2013
    Messages:
    175
    Likes Received:
    0
    Re: Preventing & Recovering a lost Phantom from a fly away

    (This is aimed at DJI, not bendronepilot, who obviously took a lot of time and thought to assemble that helpful checklist)

    Alternately, you could tie a string to the left skid, well either skid actually, and let the string out as you fly further away, then reel it in as you return. If the Phantom starts to fly away in a manner you are uncomfortable with, hold the line firmly. If you believe it has escaped completely, merely start reeling in the string, or just follow the string right to the Phantom! This will allow you to find your Phantom every time it gets away.

    C'mon DJI, there are some issues we'd like your feedback and action on. Trust me, if we know you're working on it and you share information we could be good friends that help each other. Otherwise? We might become unruly and start asking for money back and stuff like that.

    Oh, what's that, we ARE asking for compensation of some type or even an acknowledgement that there's a problem?


    OK, I'll stop now.

    :?
     
  5. drone4me

    Joined:
    Oct 21, 2013
    Messages:
    73
    Likes Received:
    1
    Re: Preventing & Recovering a lost Phantom from a fly away

    seems like a gps bug to me. the gps looks like it gets confused or corrupted causing it to fly to another coordinate. you can also easily spoof gps coordinates to the receiver too since gps comms are not authenticated in our commercial gps satellites.

    dji can incorporate a fix such that if there is too much delta from t1 over time, it should throw those out.
     
  6. ChesterT

    Joined:
    Dec 1, 2013
    Messages:
    34
    Likes Received:
    1
    Location:
    Cecil, Georgia
    Re: Preventing & Recovering a lost Phantom from a fly away

    BenDronePilot thanks for that post, I am sure it will help one of us very much!

    I do have one question however "3) Do not calibrate your compass before every flight, this is not necessary and may actually increase your chance of having a problem."

    Would you mind elaborating on this statement? I am under the impression that it is 'wise' to calibrate the compass before EVERY flight? Is this incorrect?

    I live on a 15 acre tract of land and so far fly nowhere except in my back yard, but before each flight, I always calibrate the compass, even though I am taking off from the exact same spot each time. When I take my P2V out and turn it on, if I want to get the slow blinking green rear LEDS, I must do a calibration.

    Thanks,
    ChesterT
     
  7. hawk300

    Joined:
    Dec 16, 2013
    Messages:
    5
    Likes Received:
    0
    Location:
    UAE
    Re: Preventing & Recovering a lost Phantom from a fly away

    Hello Guys, I am going to attach a small 3G GPS tracker. My concern is interference with Tx, RX & WiFi signal from 3G mobile signal.
    Please comment...........

    Regards
     
  8. gunslinger

    gunslinger Moderator
    Staff Member

    Joined:
    Nov 3, 2013
    Messages:
    2,722
    Likes Received:
    497
    Location:
    Least Coast...
    Re: Preventing & Recovering a lost Phantom from a fly away

    Nice... Always enjoy seeing, and taking advantage of, well thought out documentation...

    -slinger
     
  9. BenDronePilot

    Joined:
    Dec 7, 2013
    Messages:
    1,204
    Likes Received:
    131
    Re: Preventing & Recovering a lost Phantom from a fly away

    At least two reported fly aways posted on these forms were from people unnecessarily calibrating their compass before each flight. Even the CEO of DJI Collin tells you this in a video that it only need be done once unless changing location.

    The problem is this, The compass is very sensitive and needs to be done carefully and with the least amount of interference causing materials nearby when it's done. Among other things keep your keys and cell phones or computers away. Don't calibrate over concrete or near power lines etc. Ideally it should be done once in an open grassy area. The purpose of the calibration is that the Phantom knows what part of the world you're in, like north america vs South America or Australia vs England. Just moving flying position by a few or even a few hundred miles does not necessitate additional compass calibrations. It's also good to have the Phantom facing magnetic north when you begin. Do to what a sensitive procedure compass calibration is you're increasing your chance of having compass related fly aways should you inadvertantly have a problem while making an unnecessary calibration.

    Moral of the story, do it right and do it once unless changing your location on the globe or the phantom doesn't seem to fly right or you get a warning specifically telling you that a new calibration should be done.
     
  10. iDrone

    Joined:
    Nov 14, 2013
    Messages:
    612
    Likes Received:
    2
    Location:
    Los Angeles, California USA
    Re: Preventing & Recovering a lost Phantom from a fly away

    Nice job BenDronePilot. Couple adds: Current firmware (v1.05) measures relative altitude & initiates an ascent to approx 60' to clear objects whenever an RTH is called. If already above 60' it holds that higher altitude and begins the flight back home. It's also a good idea to pre-cache the maps in Find My Phantom before flying. Open Find My Phantom while connected to cellular or WiFi and pinch & zoom your intended flight area in both normal & satellite view. Then when you connect to your phone to your repeater and start flying, you won't need to be connected to the internet.

    iDrone
     
  11. Migmon

    Joined:
    Nov 27, 2013
    Messages:
    148
    Likes Received:
    1
    Re: Preventing & Recovering a lost Phantom from a fly away

    Doing a compas config sets the declination so the compas knows where is at for true and magnetic north, you only need to set it up if you move a hundred or so miles away from the last config. With all these flyways the authors of the threads never state weather or not they switched to attitude or manual mode for recovery attempts. I ditched manual mode for return to home mode, but perhaps I should ditch RTH and replace with manual and just rely on powering off the controller for RTH.

    Also what 3G gps are people using and where are people mounting it?
     
  12. Noël

    Noël Guest

    Re: Preventing & Recovering a lost Phantom from a fly away

    I've setup my S1 for GPS / ATTI / MANUAL.
    The plan for going home it to turn off my transmitter (never tested it)

    So.. If it's true that a fly away is caused by GPS loss, than flying in GPS mode from outside into a building (garage/hangar) should trigger a fly away.

    Anyone here willing to try / test this?

    One more thing.
    I always wait for the all green, and a home point lock before takeoff. Now what happens when flying in ATTI or MANUAL and the TX signal is lost? Does it go into "home mode" and fly back to the recorded "home point"?
     
  13. iDrone

    Joined:
    Nov 14, 2013
    Messages:
    612
    Likes Received:
    2
    Location:
    Los Angeles, California USA
    Re: Preventing & Recovering a lost Phantom from a fly away

    According to DJI one possible cause of a fly-away is a conflict between Compass & GPS data as a result of an improper compass calibration. It's been theorized that the conflict generates an error which accumulates until the AutoPilot attempts to reorient and/or reposition the aircraft towards the erroneous "correct direction" or "correct position" resulting in the now infamous spin-out or fly-away.

    Do a clean Compass Dance, test low & slow, if your PV makes large circles during a hover chances are your compass needs a better (cleaner) calibration as in open field away from metal, buried pipes & cables, you know the drill.

    iDrone
     
  14. gpauk

    Joined:
    Nov 16, 2013
    Messages:
    567
    Likes Received:
    1
    Location:
    Aberdeenshire, Scotland
    Re: Preventing & Recovering a lost Phantom from a fly away

    I'd be very careful....
    From what I've seen the receiver front end isn't very tolerant of strong signal interference....
     
  15. gpauk

    Joined:
    Nov 16, 2013
    Messages:
    567
    Likes Received:
    1
    Location:
    Aberdeenshire, Scotland
    Re: Preventing & Recovering a lost Phantom from a fly away

    Firmware flyaways (as opposed to hardware fails) are usually a result of conflicted data from GPS and IMU (could be accel, compass, gyro, baro...), there are known ways of preventing fly-aways... Some of that technology is patented, so there will be licensing issues and therefore a cost to us, if dji implement it!
     
  16. iDrone

    Joined:
    Nov 14, 2013
    Messages:
    612
    Likes Received:
    2
    Location:
    Los Angeles, California USA
    Re: Preventing & Recovering a lost Phantom from a fly away

    ...that explains a lot, esp the delay in acknowledging & resolving this issue.

    iDrone
     
  17. Noël

    Noël Guest

    Re: Preventing & Recovering a lost Phantom from a fly away

    Wow.. Just tested something here and I'm not sure what to think of it.

    I removed the props from the Vision, and prepared it for a "simulated" flight.
    After the all green outside (in GPS mode) I simulated a takeoff, walked inside the garage (to make it lose GPS signal) and slammed the door close (to simulated a sudden pressure rise).
    The Vision reacted in kind of a weird way. It even made a noise that I've never heard before (kind of loud chirping sound from one of the motors).

    I will try to redo this later today with some video recording (if I can find a video recorder)
     
  18. Ton4

    Joined:
    Nov 28, 2013
    Messages:
    348
    Likes Received:
    1
    Re: Preventing & Recovering a lost Phantom from a fly away

    I suppose you mean calibration by "config" ?

    Maybe true if the Naza has a database with inclinations from all over the world, but then a gps location would be enough.

    I don't think the Naza cares about the true north. I think it will always use the magnetic north to navigate. (Therefore always navigates in "circles" in places with a high inclination)

    I saw a guy on internet setting the compass of a naza (not mounted on Phantom, on other copter, hex if i remember well, with the naza gps/compass on top) in alignment with the true north, therefore eliminating the inclination.

    Afaik the Wookong of DJI has a function where it notices navigation errors related to inclination, and adjusts the north reference accordingly, automatically. Don't think Phantoms have this.

    True fly aways are Naza software crashes imho. A series of unexpected values (or some hardware fault) and kaboom. And without a brain, the Phantom just takes off, maybe just stuck in the last command it recieved. Probably the naza reboots after the crash, but does not find itself in a usual boot up situation, motors off, with little movement, and may crash again.

    Any sudden unexpected changes in input could be detected imho. If its a "strange" gps signal, large change in air pressure, magnetic field, radio interference or whatever.

    For instance, if the compass suddenly changes 45 degrees in direction without a good "navigation reason" it should be considered suspect. Its of outside origin.





    Sent from my SM-T311 using Tapatalk
     
  19. LeoS

    Joined:
    Nov 25, 2013
    Messages:
    747
    Likes Received:
    1
    Re: Preventing & Recovering a lost Phantom from a fly away

    Are you sure you're not oversimplifying the 'simulation'?
    Did you have a second person to move the phantom as you make the right motions with the remote?
     
  20. Noël

    Noël Guest

    Re: Preventing & Recovering a lost Phantom from a fly away

    I probably am (was doing this alone), and will leave it at this! (still no clue what that noise was)
    btw. For me by putting a hand on top of the Vision makes it also lose the satellite connection.