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What happens if there is conflict with compass & GPS.

Discussion in 'Phantom 1 Discussion' started by Miika, Jun 8, 2015.

  1. Miika

    Aug 31, 2013
    Likes Received:
    Helsinki, Finland
    What happens when compass is off by lets say 180 degrees. So north is south and south is north. If you engage RTH and flight controller tries to fly north... is there somesort of logic in the flight controller that solves this kind of situations. Obviously the flight controller knows that the drone isnt flying to north as it's locations is moving to south?

    What happens if your compass is giving a false reading? Does the flight controller still keep using that data and fly further away even when its GPS knows that it's not going to right direction. Is this one of the reasons why drones keep flying away? Could this be solved with some flight controller logic that would make the flight controller to stop following compass readings if the drone doesnt fly into the right direction based on its readings.

    A smart flight controller could fix it's heading based on gps data as it knows in which direction the drone is heading even without compass at all. So in a scenario where compass has gone mad, it would be possible to have logic in flight controller that could fly home voiding the compass reading.
  2. IflyinWY

    Sep 12, 2014
    Likes Received:
    Where the deer and the antelope play
    Yikes, that's a bunch of questions and what if's. Great ones, if you're on the right track. :)

    If you haven't noticed, most of the birds that fly away are not in the P1 or FC40 forums. It's the P2s with all their high tech electronics which have brought genuine "fly away" into the picture. I realize there probably have been some P1 & FC40 fly aways, but I can see where most, if not all were pilot induced.

    In response to paragraph 1:
    If I am not mistaken, RTH will use GPS to get home. I do not know if there will be any Compass involvement in the process. I don't see why there would be, because the Phantom doesn't care which direction it is pointed when it executes RTH. At least that has been my experience.

    In response to paragraph 2:
    If the compass is giving a false reading, the Phantom won't know which direction it is heading.
    As previously stated, I don't think it matters what the heading is. I think the Flight Controller already has the logic to cope with a bad compass. If it doesn't, it certainly should, so you have a great idea.

    Paragraph 3 assumes you are correct about GPS being able to tell the Phantom it's heading. I believe this is, or could be true, but only if the Phantom covers some distance to establish it's heading.
    Here is how I am thinking of it. GPS offers LOCATION information. If the Phantom is stationary, how would it know which direction it is facing?

    Now if there were a "Smart Controller" as I think you envision, there would need to be a change in location in order for the Phantom to "orient" itself in relation to heading.

    I think you should mount your compass on the outside of the proper leg, that will swap North with South. Give it a fly and see what happens. I would not suggest doing this in a populated area or near a lake or ocean. You might want to tie a string to it, and/or put a tracking device onboard prior to the test.

    Am I on the same page as you, or totally lost on the subject?

    Oh yea, you've got some really cool videos. Thanks for sharing :D
    #2 IflyinWY, Jun 11, 2015
    Last edited: Jun 11, 2015