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Flyaway Prevention Idea Gone South...???

Discussion in 'Phantom 2 Vision + Discussion' started by RedRyderMedia, May 8, 2014.

  1. RedRyderMedia

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    I had an idea I hoped would help avoid flyaways. I performed my normal preflight procedure, watched the flashing yellow lights turn to fast flashing green and then slow flashing green. Now I'm ready to fly, but before taking off, I wanted to see if I could verify home and compass with the radar function. I picked up the Phantom and walked about 100ft away from Home and sat the Phantom down pointed 180 degrees away from its initial/Home position.

    I expected to see the red arrow point in the opposite direction, which it did, and to see the red arrow move slightly away from Home. I thought this would verify the compass was working well and also verify I had established Home, which would reduce the chance of a flyaway. To my surprise, after a few seconds, the distance from home indicator changed from about 100ft to 0ft.

    I hadn't expected that and didn't know what to do with that. It was like the Phantom had established a new Home position. That worried me a little. So, I picked the Phantom up and walked back to where I had established Home originally. To my surprise, now the distance from Home was about 100ft, but after a few seconds, the display turned to zero again. I actually did this twice to make sure.

    I thought about stopping at this point and going home to think......but I didn't. I thought maybe this strange behavior had something to do with altitude or setting the Phantom down stationary, so I decided to take off and fly from the first Home position to the other and see what happened. I took off and hovered at about 10ft. Everything seemed normal, so I flew sideways over to my second Home. Once the Phantom got there, it started to fly a little irratically, the lights changed, it ascended by itself and proceeded to RTH right next to me. At that point I decided to just drive home and scratch my head.

    So what am I doing wrong? This is a brand new never before flown P2V+ with new batteries, fully charged, freshly compass calibrated. I had at times 11 satellites, although at times I had fewer. S1 and S2 were up and I was in Ready to Fly/Phantom mode. I was flying in the middle of a huge open field with no buildings or trees or large metal objects or anything but dirt and a few weeds. I'm a little worries about this bird. Maybe I confused it, but it now worries me.
     
  2. srandall25

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    Prior to moving the Phantom to the new location 100' away, did you at any point start the motors? I'm thinking that 'maybe' the home location isn't 'locked' until the motors are actually started. If this was the case then maybe the home point would always recalculate based on where the phantom resides provided there are steady green lights and GPS lock (6+ satellites). I don't really know, just guessing as to why or how this could have happened. It would be nice to have a little more in depth knowledge of the algorithm behind the home lock. I'm also curious if the 'Find My Phantom' feature can serve as an indicator that the home lock position is indeed accurate... in other words, once i get the green blinking lights, if I then look at the 'Find My Phantom' feature, would it provide me the location on the map that the Phantom recognizes as the 'home point' location. If so, this could alleviate some concerns others were having of an incorrect home location being recorded leading to 'fly-aways'...
     
  3. RedRyderMedia

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    I didn't start the motors before moving the Phantom, but my understanding is the home lock happens when the fast flash green turns to slow.
     
  4. srandall25

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    Did you at any point fly it from home point 2 and do an RTH to see if it would go back to home point 2 instead of what should really have been the home point?
     
  5. Aqeel200

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    interesting test. maybe we need more extensive test in this scenario to conclude some of the logic of the firmware..i would not want to do an extensive test cases in a flyaway scenario.. :D ..DJI is to do that in their lab n test flight/field. :D
     
  6. DBS

    DBS

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    Home position is "verified as having enough satellites" when you see the slow blinking lights that show you have enough satellites acquired...
    Home position is "recorded" when you first launch the Phantom....

    It is doing exactly what it should when it has good GPS data... it was following your location movement and keeping track until you launched and recorded the home position.

    Don't know why it would start to fly erratically and return to home like that... but it shows that it marked the position that it took off from so that's as described in the manual.

    Not sure why this would be viewed as strange behavior... based on the description of what the Phantom is designed to do... it did that...

    I do the same thing you did all the time with the same results... set it down... power on... wait till slow blinking green... move the phantom to a new location... Red arrow follows suit because it is aware of this new location and hasn't recorded a home position yet because it hasn't been launched yet... launch and record home position... trigger failsafe and it comes back and lands right next to me every time.
     
  7. 4wd

    4wd

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    A while ago there was a thread about setting home at your house without launching (I think), then driving several miles to maximise the possible flight distance - letting it return to the preset home position, 2 or 3 miles away.
    This seems at odds with your experience?

    I thought that the second sequence of rapid green flashes indicated home recorded and that *should* be done before taking off.
    You can initiate a new home lock in the air by toggling S2 which also shows a rapid green flash sequence.
     
  8. Madwak

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    The "find my phantom" feature ONLY shows you the phantoms location with respect to the location of your phone, so if you took the phone with you when you moved location as soon as the phone realised it had moved then the two icons would appear next to each other as is being described - simples. :)
     
  9. DBS

    DBS

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    Dude... nobody is talking about the find my phantom feature here... wrong thread
     
  10. DBS

    DBS

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    I guess I'm not arguing other threads... or what "should" be the scenario when lights are flashing and people haven't done what the OP is describing... I'm just relating that I've done it dozens of times now... and it always marks the location where i launched the drone from, even if that's a new location since acquiring satellites and going to slow blinking green... even if it's the 3rd or 4th new location since slow blinking green ... In other words I've moved the phantom 4 times before launch.... it marks the home position as the spot where it took off from... not the spot where I set it down the first time and it first acquired the satellites.
     
  11. markab

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    The manual says when you see a set of rapid flashing greens your home position is set and you are good to go.

    What a lot of people do not realise is this can happen in 2 parts, 1 set of rapid greens for compass direction set and the second set for satellite home position. If you get satellite lock quickly these 2 parts can happen at the same time giving you one long set of rapid greens but very often if satellite lock is slow, you will get one set of rapid greens then after some time a second set, sometimes I note on my phantom 2 in naza mode the second set can be 10 or more seconds from the first.

    So the question would be are people taking off without without full home position recording and initialization because the manual sucks at explaining it may occur in 2 parts with a delay?

    Would be much better to have a single led on the top that only lights when everything is 100% for flying, is very difficult to leave the craft untouched initializing on a sunny day and keep track of all light sequences after start up.
     
  12. Madwak

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    Respectfully I think you need to reread the opening post as the "find my phantom" feature appears to be what this thread is about? If its me that's wrong then sorry and I'll get my coat :(

    Edit* I get it now, I was assuming that people knew that the "radar" is the "find my phantom" but without the maps, so my explanation IS relevant :)
     
  13. RedRyderMedia

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    No
     
  14. RedRyderMedia

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    I don't plan to repeat this "test"....I'm concerned about flying this bird at all!
     
  15. RedRyderMedia

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    That is exactly what it seemed to be doing. It seemed to be establishing a new home position each time I moved it. It finally established a home position at the location it took off from because that's where it RTH when it initiated that sequence. I didn't try what you apparently do often which is to take off from the second Home position and have it RTH from there.
     
  16. RedRyderMedia

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    I agree it is difficult to see the lights on the underside. I actually set the Phantom down on top of a small plastic bucket with a lid. I have two mirrors on the lid so I can stand at a short distance and easily watch the light in the mirrors. As for taking off without "full home position", I carefully watch for the slow blinking lights. I have never experienced a long fast blinking light sequence.
     
  17. RedRyderMedia

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    When I referred to the radar, I meant the small radar in the lower left corner of the FPV screen. When you touch the icon, it expands to a larger version in the middle of the screen.....then toggles back to the lower left corner of the screen when touched again.
     
  18. Flighttime

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    In the Naza-M manual it says home point will lock when it gets enough satellites AND motors are started up.

    You can reset home point in flight by flipping the S2 switch
     
  19. RedRyderMedia

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    I was aware you can change home position in mid-air, but I don't think I've ever read in the P2V+ manual where you can change home position by relocating the Phantom before CSC. It seems clear though, home position isn't established until something happens after getting satellite lock and the slow flashing green lights. It's not clear to me yet if that "something happens" is CSC or actual takeoff or something else.
    If that something else is CSC, I can see how this could fool someone into thinking home position is established at CSC, when home position is established at CSC ONLY IF YOU HAVE SATELITE LOCK FIRST. If someone wasn't patient enough, or not careful enough to watch the lights, if they thought home was set at CSC, they could be surprised when their Phantom took off in an unexpected direction when RTH was initiated.
     
  20. DBS

    DBS

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    Radar HUD is the phantoms current location in real time relative to its recorded home point set at takeoff regardless of where the controller is located at that time... The operator can walk a half mile away but the radar still points to the position where the phantom launched... it does not include any GPS info from the operators cell phone or tablet.

    "Find my Phantom" is the Phantom's last known recorded GPS position reported along with the operators cell phone or tablet's current position in real time...

    These two displays are very different from eachother and should not be confused.