Welcome to PhantomPilots.com

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

Unexplained behavior on First Ground Station flight

Discussion in 'Phantom 2 Vision Discussion' started by klausdim, Jan 31, 2015.

  1. klausdim

    Joined:
    Jan 31, 2015
    Messages:
    3
    Likes Received:
    0
    I am a new phantom 2 vision plus pilot. I have flown it around various placed for about two weeks. On this flight, I used the ground station feature for the first time. I started by running a short test to make sure it worked properly. I set way points on each corner of a large field, and then had it return to the center of the field. All worked well. I was ready for a real flight, or so I thought. I set a way point at a friend’s house, about 1 mile away from the field, and another at one edge of the field, and then had it fly back to the center of the field. Then, I pushed GO. Off it went. I lost sight of it after a few minutes. Then I lost the control signal (“Phantom connection broken”) another few minutes later. Another few minutes later, I lost video. The ground station altitude indicator read "0". Was that because I lost connection, or is it no longer in the air? I had no idea, but I decided to wait patiently.

    I was a bit worried, but I was not panicked. I had lost sight of the phantom before, and experienced the failsafe return to home feature. I simply turned off the controller, and it came racing home. But I was beginning to think that this was not happening this time. Another five minutes passed, and there was still no sight of the phantom. Now I was getting quite worried. It was getting obvious to me that the Phantom had not returned home when it lost WiFi connection. What to do?

    I jumped in the car and drove to my friend’s house, trying to regain the signal while I was driving. No luck. Nor did I see it in the sky. When I arrived in at my friend’s house, I stepped out of the car and made a concerted effort to reconnect to the phantom. I power cycled the controller. I restarted the vision app. I still had no video, but I saw a sign of life! The ground station section of the DJI Vision app had an altitude indication of 180 feet. That sounded promising. I clicked on the “return home” icon on ground station. The app asked me to verify the “return to home” instruction, which I did. I then drove back to the field.

    When I got back to the field, the phantom was hovering over the center of the field. I flipped the S1 switch down and up, regained control over the phantom, and brought it in for a landing. I really thought I had lost it. I was relieved and delighted that I retrieved the phantom. But I still did not know what happened.

    I checked out the video to see what the phantom actually did. This is what the video showed: It flew from the field to the first way point (my friend’s house). Then it hovered at that location for about 9 minutes. Then it turned around, and headed back directly to the field, bypassing the second way point. I read through the manual and forum posts to try to understand this behavior.

    I learned that the phantom does NOT return home when the WiFi signal is lost when using ground station. Instead, the phantom continues the mission that was defined in ground station. So that explains why it did not return home. However, it does not explain why it decided to hover over the first way point. As I understand it, the phantom should have continued to the second way point, and then return to the field. Had the video shown a one-minute hover, I would have concluded that everything would have been fine if I just waited longer in the field. Instead, the phantom hovered over the first way point and skipped the second way point when returning home. This suggests to me that the phantom was stuck hovering over the first way point until I drove closer to re-establish WiFi contact. I assume that the phantom returned home in response to the “go home” instruction after I regained contact.

    Does anyone understand why the phantom behaved this way? Or is this operator error of some sort? Until I understand what went wrong, I am hesitant to trust ground station again. Any ideas would be appreciated!
     
  2. kyle

    Joined:
    Jan 31, 2015
    Messages:
    1
    Likes Received:
    0
    Can anyone comment on how to ensure all waypoints are delivered to a Phantom 2 Vision before the mission starts?

    I flew my first longer Ground Station flight today, too. The longest waypoint was about 1300 feet away. After clicking done I saw a waypoint(s) being transmitted to the Phantom so I thought all was okay, until I saw it transmitting the second waypoint after it reached the first, then another after the next waypoint, etc.

    Whether by design or user error, it appears not all waypoints were transmitted before it started the flight. Fortunately I didn't lose ground station contact so it completed it's mission.

    If the same happened to your phantom, the behavior could be explained this way: Your Phantom flew to your friend's house then stopped because it didn't have the next waypoint and waited for instruction. Perhaps it lost signal while you were in the car or the battery reached threshold then returned home.

    Another lesson learned: I started the mission while it was on the ground. It went straight to the first waypoint and tipped over in some tall weeds. The fix was to take off manually then start the mission. The other time I tried a Ground Station Flight I'm certain it went straight up, first, then executed it's mission.

    Today's flying was with the new firmware. Other than described above, everything worked flawlessly.
     
  3. klausdim

    Joined:
    Jan 31, 2015
    Messages:
    3
    Likes Received:
    0
    I was thinking about that explanation. Supposedly, the phantom gets all waypoints at the beginning of the flight. I think I will go back to the field for some systematic experiments to verify that.
     
  4. MikeON

    Joined:
    Nov 5, 2013
    Messages:
    277
    Likes Received:
    29
    Location:
    Pennsylvania, USA
    I'm wondering how you set a waypoint 1 mile away from home point. Ground station will not allow waypoints more than 500m from the home point.
     
  5. BWJ

    BWJ

    Joined:
    Aug 19, 2014
    Messages:
    144
    Likes Received:
    0
    Location:
    Denmark
    You should be absolute sure that you have >6 sat. in groundstation, and check space weather for solar flares witch interfere sat lock.
    If it in a mission go <5 sat. it will hover until it regain sats, otherwise it will hover until it auto land cause empty battery.
     
  6. Umpa

    Joined:
    Dec 17, 2014
    Messages:
    35
    Likes Received:
    0
    What is does is upload ALL the way points to the phantom, I must point out that losing wifi (phantom vision app) will not affect its mission, nor will losing tx connection (they are different) what will happen is that when you are in range the DJIVision app will seem to upload the waypoints to the phantom again, however I don't think that is what really happens - what I think is happening is the app is syncing with the phantom because the phantom will NOT be in the same location as when the connection broke. Upon return the phantom hovers awaiting the instruction to return home.


    The app via wifi nor the tx uploads waypoints on the fly or adhoc whilst a mission is in progress, it is truly a fit and forget system. Why your system failed to reach waypoint 2 is very strange. Like BJW says it might be because of a GPS issue, I am not sure of that procedure but sounds feasible. I have flown many many GS Missions and have not had a failure yet.