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How to control PV2+ if GPS signal is not stable ?

Discussion in 'Phantom 2 Vision + Discussion' started by AAC, Jul 29, 2014.

  1. AAC

    AAC

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    I set PV2+ 4 waypoints GPS cruising in my tiny front / back yard not more than 3000 sq ft. There were tree nearby. 6 satellite signal when took off. When it flew to Waypoint (1), satellite down to 1 and later up to 5. As a result, my PV2+ stopped moving on at Waypoint (1), it was up and down or moving left and right freely like a kite. I shut down remote controller without pull down S1, hoping it would returning home immediately. No luck, it kept flying 100 ft above me for another 2 minutes uncontrollable. Eventually, I took it down by manual control.
    My questions are :
    1) Was the flying area or WayPoints too short or tool small for GPS to set it up accurately ? I had to enlarge the street map on my cell phone screen significantly before I could move my fingers to set Waypoints. My house on map was blurry. I picked the wrong area to test fly ?
    2) What made the Signal Fail returning flight mode failed ? Lost of or weak GPS signal ? I shut down the power on remote controller, signal lost message displayed on screen, but it didn't come home, what's wrong ?
    3) What quick and simple action to cancel all flights either in GPS or manual mode and have it back and land to home point safely ? This is very important for a new PV2+ learner. Whenever it's far away or I couldn't figure out the camera direction, I always have problem to control it properly or in a panic.
     
  2. cahutch

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    without GPS, the phantom can't know where it is.
    So...
    Return to home doesn't work without GPS.
    Flight mode is atti mode. It will drift with the wind.
    Ground station way points are set by GPS and Require GPS to function.
    You can't be in GPS mode without GPS.

    It amazes me that people don't understand this basic functionality.
    Please Read The Manual.

    Ask yourself,
    How could it return by itself if it doesn't have a GPS signal?
    How could it hover and hold it's position without a GPS signal?
    If GPS satellites are less than 6, it cannot determine it's position and if it doesn't know where it is, it cannot know how to get back to home.
     
  3. DCGOO

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    You should not have taken off if you only had 6 satellites captured. You will not get full green until more than 6 have been acquired. They also need to be solidly available, not just a flip to 6 and quick takeoff. Sometimes it can take 10 or 15 minutes to get to 7 or 8. It also depends on your precise location, and how clear the view to the sky is, in all directions. If you ever drop below 6 satellites, GPS is shut off, and everything that requires GPS no longer works, including waypoints, RTH, hover in place, and so forth.
     
  4. cahutch

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    Most people don't realize that the majority of the satellites you're receiving are not directly above you.
    A few may be, but most will be to the side, closer to the horizon, so buildings, hills and tress can block more than a few satellites, as will dropping down into a canyon.

    Just something to keep in mind when you're flying, don't fly somewhere that blocks your phantom's view of the sky all around you, not just direct above.
    If you get too close to a building or tree, you may lose 50% of the visible sky.
     
  5. AAC

    AAC

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    Thanks for all advice.
    I was panic when it was 150 ft high, 200 ft away from me or lost GPS control.
    If GPS is stable or strong, will it cruise accurately in a 2000 sq ft back yard ?
     
  6. DCGOO

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    If you have good GPS, the bird will hover in place within a few feet, hands off. It is pretty amazing to watch it work to maintain position.

    Without GPS the bird will follow the wind. The accelerometer will keep it level, but it has no idea of where it is, and it will wander all over depending on how windy it is at altitude. A bit of practice on a not too windy day, will help you figure it out.

    2000 Sq feet is a very small place to be playing with your Phantom. My yard is 25,000 sq feet, and I go to a nearby school football field to fly.
     
  7. AAC

    AAC

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    The reason I flew it in my backyard is to capture video of my new home for my parents living aboard.
    I'm a novice dummy pilot. To play safe, I set GPS waypoint in my tiny little house but it was not really pick up good GPS signal in my area as mentioned previously.
    I guess the last option is to control it manually to fly over my house. However, my concern is when flying to the other side of my house, I may have control problem if the live view on screen is freeze or delay. Is this a firmware or WiFi issue ? I watched demo fly on Youtube, their live view was on and off even flying over golf course.
     
  8. happydays

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    Firstly, you must have had six satellites in order to set the waypoints initially as you can't do that with less than 6. So all good there.

    When it got to the first waypoint, it will naturally hover until it sets course for the next one. However if the satellites detected had fallen to under 6 (as you indicated) then it will hover in position until it regains 6 and then can continue on the set course. However, while waiting it will be in ATTI mode and therefore subject to being blown about by the wind.

    Turning off the controller while in waypoints mode will have no affect at all as it is on a pre-programmed flight path. Mine regularly goes out of sight behind trees and buildings (this would normally cause a loss of control signal) but the craft keeps on its original course.

    As far as I can see, all of the above was perfectly normal. You always have the option to cancel the mission and to initiate return to home via the waypoints screen, as long as you are in control range.

    If you don't believe this, try setting up a short waypoint course and turning off the TX when it has set off. It will complete the mission and sit there at the end waiting to be told what to do.
     
  9. AAC

    AAC

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    Appreciate your advice. I need more practice to build up my confident when it is flying away within waypoints routine. I'm really concern any wrong operation will cause damage to third party.
     
  10. happydays

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    Experiment in a big field!
     
  11. AAC

    AAC

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    When GPS signal is lost, the only option to get it back is manual operation, no other one press for home, am I correct ?

    BTW, I never find NAZA mode on screen. how come ?
     
  12. happydays

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    In the assistant software you have to click on 'Phantom' at the top and change it to NAZA. That should work. If you want the other goodies like Course Lock, Home Lock etc, you have to enable IOC in the assistant software too.
     
  13. BlackTracer

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    If GPS signal is lost and you are flying using GPS, your phantom enters non-GPS ready-to-fly (also known as ATTI mode). The phantom is stable with respect to yaw, pitch, and roll, but will not hold a position with sticks released (will move with the wind vector added in, even with stick input). So if by manual, you mean no GPS, then yes, that is your only option in non-Naza mode. Naza adds an optional full manual mode, which is not recommended except for very experienced flyers.
     
  14. DCGOO

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    This is an extremely risky proposition. I am really surprised you are not out shopping for a new phantom