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What did I do wrong?

Discussion in 'Inspire 1 Discussion' started by AndyH, Jul 17, 2015.

  1. AndyH

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    Ok,
    Though I'm not a newbie to drones in general I am a newbie to the Inspire 1 and DJI overall. The bird arrived a few days ago. I checked it, updated the firmware, and checked the telemetry.
    I have researched the Inspire and swear that I ran into the "end of the Internet" reading posts, reviews, comments, etc.
    I took it out for a short flight to feel her out.... zero problems. Yesterday, I changed my location, calibrated the IMU, calibrated the compass. Checked the mod values. Went through the checklist and took it for a low level brief flight. Used the auto land feature. She landed about 20" from where she took off. Beautiful. As she was sitting there I had about 80% battery left and decided to go for a higher flight and play with the gimbal. No problems for the first six minutes. Then the video feed got choppy, the craft got twitchy and I lost control. The Inspire was about 350 feet up and got a mind of its own. After a short bit, I switched it to Atti and still had no control. It went completely out of site. Thankfully, to my biggest relief, I followed the GPS trail on the pilot App and it had landed luckily on a empty football field about a half mile away. It's hard to beleive the craft did this on its own so I reviewed my actions thoroughly. I had calibrated the IMU and the compass. Checked the mod values afterwards. Checked the compass. All of my inconsistencies and findings are listed below:

    1 - I was using a Samsung Note 4 that's not listed in the approved apps (It was starting to lag into the flight)
    2 - I had not recalibrated the compass right before the second flight. I actually just let it sit a few seconds and took off again using auto take off.
    3 - After carefully reviewing the video, I had noticed that one of the antennas on the RC was down. I was sure they were up when I started.
    4 - It stopped filming exactly when I lost control.
    5 - I never checked the channels on the app when I got there.

    The field is a long time registered AMA field and I have flown many an RC craft there with no transmitter problems, just operator goofs. Could anyone help me figure this out? I tried to look for the flight logs but I have no idea where they are. I've read plenty of posts about where they are but I can't see them.
    The amusing thing (its only amusing cause the bird was found unharmed) was that I kept reassuring myself that I would use the trackimo to get a good GPS location. The only thing that I would actually be tracking would be my shorts, because affixing it to the craft was omitted from my preflight checklist. I would appreciate any input (you can even call me bumbling idiot) as to why the bird lost control.

    Greatly appreciated ,
    Andy
     
  2. Richard Hurst

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    Hi

    it's hard to say really what happened here. I don't think it was done to the fact you were using the Note 4 and I have taken off many times after doing the first initial compass calibration without any issues whatsoever. Possibly the antenna being in the down position may have played a part in this but it is also weird that the video stopped recording at the moment you lost control. You will find the flight logs in the App, Under user centre.
     
  3. Aviator

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    Well from what you have said it looks likely that the Samsung or the flight controller was issuing commands to the AC that were not instigated by you.
    I say this because the video switched off and this does not normally happen in a fly away situation.
    The fact that the app recorded the GPS trail means that the comms were not disconnected completely.

    The other possibility could be that the AC was accepting commands from another source.
    The fact that your AC auto landed would indicate that the battery had dropped to the point where the AC went into auto land and shut down mode.
    EDIT
    Also make sure you have multiple flight modes enabled otherwise switching to Atti will not work.
     
    #3 Aviator, Jul 17, 2015
    Last edited: Jul 17, 2015
  4. Lesmess

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    Hi Andy obviously this fly away should not have happened as you appear to have covered all bases. I have well over 60 flights with no major issues with my bird.
    I've only ever calibrated the IMU after a firmware upgrade as the values have never changed between calibrations. I do the calibration with the bird perfectly level on all axis I use a spirit level to achieve this maybe overkill but this is my routine.
    I normally only calibrate the compass after a IMU calibration at a fly site that I know gives me good results. I have the same routine as you before I fly, I check the sensor and battery values and return to home height I also check that the app is recording the bird at exactly the compass point it is pointing (i use a iPad mini 2) before take off. PS I only ever take off manually just a thing I have about auto take off. I always change the battery when I land ( always). I switch the controller and app off and go through exactly the same pre checks with the new battery. I never take off unless I have a 100% battery level. I have done around 15 flights with no compass calibration with no issues. I adopted this policy as this was the general advice from the most experienced pilots on this forum The Editor spring to mind. I have to say the issues other folks are experiencing does take the edge off the my flying enjoyment. In high winds I only fly her in open places well away from trees so I have plenty room to land her in Atti mode if I have too. She can quickly get away from you in high winds. PS I live in Nothern Scotland so always windy here. All the best with your bird it is a fantastic flying platform.
     
  5. AndyH

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    Thank all of you gentleman for your extremely helpful responses. I also appreciate that no one had called me a bumbling idiot, so far. I did find the flight logs (Thank you Richard) and reviewed them. I noticed that no streaming data, other than max alt and distance flown, was corresponding to the GPS path. I have also seen logs with stick input shown. What am I missing? Is it because I'm on an android?
    Aviator, thank you for reminding me that I never switched to airplane mode (another important preflight omission) and that I received an email notification almost the exact time that the bird went out of control.
    Lesmes, your preflight policies appear very solid. Is it important to calibrate the IMU at the flight location? I know I calibrate the compass at the site.
    One more quick question, I have batteries on order. How will I know if their firmware needs to be upgraded?
    Thank you again for your quick responses.
     
  6. Aviator

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    I use an iPad mini with all unnecessary apps turned off and in airplane mode.
    You do not need to do an IMU calibration unless you have upgraded the firmware, or, the bird has suffered a shock (crash, hard landing, transported badly)
    To upgrade the firmware on your new batteries, just put the AC upgrade file onto your SD card and start the AC with the RC turned off, the battery will get its firmware upgraded from the AC upgrade file (usually a short process).
     
  7. Lesmess

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    I carry out the IMU calibration In my home as I said level surface, I use a spirit level on the motor shafts when she is spot on calibrate the IMU. Yes calibrate the batteries I have a dedicated card for the firmware updates. Put the card in the camera and switch on the battery it will auto calibrate the battery only takes a few minutes. I have three T48 and one T 47. If the battery is at the latest firmware same as the bird nothing will happen if not the battery light start to flash and you get the beeping sound.
     
  8. AndyH

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    Thank you again gentlemen! This, by far, it's the most informative site for information. Much more helpful than DJI's site.
     
    The Editor likes this.
  9. inspireme2

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    This is the first time I have heard someone tell someone to power up an aircraft without the controller being powered up first. I'm sure you know what you're talking about but it does seem kinda risky.
     
  10. Aviator

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    I suggest you read the instructions for updating the firmware on the AC.
    Step 3 Is the relevant part
     

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  11. sanderx

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    Not really if you make sure there are no props attached to the machine. Although I agree that it does sound counterintuitive as we are always told to turn on the transmitter first before ever turning on the quad.....
     
  12. JohnHan

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    Also, if you want to do a firmware update, then this is what you must do. Otherwise of course, accepted practice is to always have the RC on before the craft.
     
  13. The Editor

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    Hi Andy,

    Sorry to hear of your misfortune with the I1 - Glad you got it back in one piece!

    Couple of comments/questions.......

    Are you saying you did an IMU calibration out in the field/flying site? Never a good idea as your aircraft should be as level as you can get it and absolutely vibration free when you run the cal. Even wind vibrations on the aircraft can upset it.

    Sounds like you did compass calibration in the field as well - my views on this are well known on the forum and personally I would never recommend doing a calibration of any kind in a location you cannot be 100% sure of. The last time I did an IMU or compass calibration was May 26. I know this because that was the last firmware release.

    Did you do a stick calibration after the FW update? I would always advise doing this since the firmware is also written to the remote as well as then aircraft and you never know what DJI has fiddled with! Its easy to do, takes seconds and only needs to be done once after FW update.

    Does your Inspire have any excessive free play in the arms at the point of the large nut on the T-Junction on the arms? There should be a little play there (a couple of mm) but not an excessive amount.

    Did you have multiple flight mode enabled via the app? If not, switching to atti would have had no effect?

    Finally, did your aircraft exhibit any kind of circular movement while it was playing up? Showing signs of nose possibly staying in the same direction but aircraft looping around in ever increasing circles?

    Let me know any of the above and I will see if we can get to the bottom of the problem.
     
  14. Neio

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    I know that the latest firmware should always be installed but I have read so many stories about this latest firmware. My Inspire1 is on schedule to be delivered today and I was contemplating whether or not I should flash it with the latest firmware (If not installed already).
     
  15. Aviator

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    IOC? Did you mean Multiple Flight Mode
     
  16. The Editor

    The Editor Moderator
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    I did - thanks!
    Now corrected :)
     
  17. AndyH

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    The Editor,
    I did do the IMU and compass at the field.
    I never did a stick calibration.
    There is a little play in the arm, but no more than 2mm, if that.
    The craft was changing its orientation during flight and even seem to acknowledge the RTH in the flight log, though it did travel mostly in ever increasing circles (clockwise). Multiple flight modes were not enabled (I'm, an idiot). Need to add that to the checklist.
    Thanks again for your help.
     
  18. Yardman

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    Check pk index for day of flight. Don't think it would turn off the camera though.


    Sent from my iPad using Tapatalk
     
  19. Leszek Kedziora

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    All the advices that have been written here are very right. One that was not mentioned is the impact of the environment. Especially radio interferrences that IMHO would have played important role in this case. I am very obsessive not to fly close to directional antennas and evry kind of wifi sources like houses, hotels etc.
     
  20. AndyH

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    I have flown there many times with other RC Aircraft and quads on 2.4 with DSM though I had never flown that high. The only thing that puzzles me is why the pilot app seemed to freeze up with no video. The display seemed to freeze up and stop tracking until a about a minute later. Then, the GPS location was accurate. The flight log was complete.