Welcome to PhantomPilots.com

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

Course Lock

Discussion in 'Phantom 2 Vision + Discussion' started by snowghost, Feb 23, 2015.

  1. snowghost

    Joined:
    Feb 13, 2015
    Messages:
    1,056
    Likes Received:
    212
    Location:
    SoCal, USA
    Was wondering if Course Lock still works if no GPS signal. It seems it could if it just knew the orientation upon launch. I guess I could try it in Atti Mode. But thought somebody here would know.
     
  2. msinger

    Approved Vendor

    Joined:
    Oct 30, 2014
    Messages:
    18,768
    Likes Received:
    5,522
    Location:
    US
    Right -- no GPS required. Course Lock uses the compass to figure out which way it should be heading.
     
  3. snowghost

    Joined:
    Feb 13, 2015
    Messages:
    1,056
    Likes Received:
    212
    Location:
    SoCal, USA
    That's good to know in an emergency, as with no GPS, no Failsafe or Home Lock.
     
  4. BlackTracer

    Joined:
    Mar 29, 2014
    Messages:
    980
    Likes Received:
    22
    Location:
    Winter Park, FL USA
    This raises a question. If sats drop below 6 and it switches to atti, if I then select CL, will it stop drifting with the wind and maintain straightline course direction? I am thinking no and hoping yes but not 100% sure.
     
  5. bbfpv

    Joined:
    Feb 3, 2015
    Messages:
    3,744
    Likes Received:
    1,092
    Location:
    Long Island, NY
    Nope. it will drift but maintain course direction, so you'll end up moving diagonally with the wind.
     
  6. max

    max

    Joined:
    Sep 19, 2014
    Messages:
    199
    Likes Received:
    6
    Agreed, this is useful information to know. I can't think of a specific situation in which it would be useful, but still good to know! Loss of GPS and loss of FPV, and loss of visual orientation, but maintenance of control.
     
  7. snowghost

    Joined:
    Feb 13, 2015
    Messages:
    1,056
    Likes Received:
    212
    Location:
    SoCal, USA
    Yes control is key--if it is but a dot in the sky, at least you'll know the right way to bring it in closer without trial and error.
     
  8. aartsf

    Joined:
    Sep 23, 2014
    Messages:
    346
    Likes Received:
    3
    Hay msinger,
    Did you test that realtime? The reason I ask is that in my understanding compass-info is used by the flightcontroller in combination with the gps-info and not seperarely. If that indead would be the case, CL would not work without gps lock.
    Regards FA
     
  9. N017RW

    Joined:
    May 2, 2014
    Messages:
    6,236
    Likes Received:
    1,606
    Location:
    Palm Beach Co.- FL
    When [in Naza mode and] IOC is enabled, Course lock maintains a heading based on pre-take-off conditions. However it is at the mercy of ambient wind currents which determine the actual course (across the ground below).
     
  10. msinger

    Approved Vendor

    Joined:
    Oct 30, 2014
    Messages:
    18,768
    Likes Received:
    5,522
    Location:
    US
    No. But, this document states the following:
     
    #10 msinger, Feb 24, 2015
    Last edited: Nov 5, 2015
  11. mendezl

    Joined:
    Dec 14, 2014
    Messages:
    326
    Likes Received:
    10
    Location:
    Mandeville (New Orleans) Louisiana, USA
    And if you loose the compass... No course lock... So do this... Quadcopter Drone Orientation Tips for Distant Flying: http://youtu.be/qdYTCfjUVVo
     
  12. aartsf

    Joined:
    Sep 23, 2014
    Messages:
    346
    Likes Received:
    3
    The statement doesn't say it is calculating nose-direction based on only compass input. Actually it would also not be possible to calculate (nose-) direction based on the input of only one source/antenne! It would a least need input from two sources /antennes that have sufficient distance between them to enable a 'revear cross-bearing', needed to calculate the nose-direction. Right?!
     
  13. BlackTracer

    Joined:
    Mar 29, 2014
    Messages:
    980
    Likes Received:
    22
    Location:
    Winter Park, FL USA
    ??? My understanding of a magnetic compass is it can single-handedly determine direction WRT magnetic north. Maybe I am misunderstanding you?
     
  14. gbello23

    Joined:
    Jan 4, 2015
    Messages:
    51
    Likes Received:
    0
    Location:
    Toronto, Ontario
    No GPS required when in course lock.

    From the Vision guide posted on here:

    Need to know: Course Lock can be used in both 'ATTI' Mode and 'GPS' Mode. Course Lock does not require GPS
    satellite acquisition or establishing a Home Point. Course Lock relies on Orientation information only while Home Lock
    uses both position (GPS) and Orientation (compass, gyro, accelerometers).
     
  15. ccase39

    Joined:
    Jan 3, 2015
    Messages:
    471
    Likes Received:
    17
    I still don't have a good understanding of course lock and how to use it. Home lock is great but never played with course lock.
     
  16. N017RW

    Joined:
    May 2, 2014
    Messages:
    6,236
    Likes Received:
    1,606
    Location:
    Palm Beach Co.- FL
    One way to visualize it is the classic grid analogy...

    Once the CL heading has been stored during power/warm up that heading becomes the forward reference for CL flight.

    Let's say the quad was facing due West, so that's its CL reference heading.

    Now when in CL, no matter which direction the quad is facing (i.e. red banded arms) at the time of moving S2 into the middle position, pushing forward on the elevator or right stick will cause the quad to move due West.

    Moving the right stick, aileron, to the right will cause the quad to fly due North and so on.
     
  17. aartsf

    Joined:
    Sep 23, 2014
    Messages:
    346
    Likes Received:
    3
    Hay Black T
    Indead a misunderstanding. Msinger was talking about the determination of specifically the noise-direction (relatively to the magnatic north orientation); and for that, in mine opinion, the bird needs more informaion than only a compass reading (from one antenne-position). Sorry if I wasn't clear enough; engish is not my native language you know [WINKING FACE]
     
  18. N017RW

    Joined:
    May 2, 2014
    Messages:
    6,236
    Likes Received:
    1,606
    Location:
    Palm Beach Co.- FL
    A magnetic compass is all that's needed for heading indication.
    Been that way for more than a millennium.

    The Phantom has a 3-axis magnetometer.
    That's why you need to calibrate, or rather compensate, in both the horizontal and vertical planes.

    'Cross bearing" would be used to determine a position along a line.
     
  19. Monte55

    Joined:
    Apr 26, 2014
    Messages:
    2,195
    Likes Received:
    517
    Location:
    Raymore Missouri
    I would like to add something. I think it's important to really pay attention to which direction the quad is pointing at start up. I generally use North. Pick a tree, a building etc ....any point of reference and keep that in mind. If you are facing the same way the quad is at start up and flying..it's easy ...BUT, if you fly somewhere else and turn your body facing quad and hit CL, it won't make sense to you, unless you're really thinking. If YOU move far enough away from take off point while flying and and hit HL, pull the right stick back, It's not coming back to you but it goes back to starting position. Some keep thinking the quad will come back to them no matter where they move to, but that's not the case. When I fly at the park, I always start up North. So after getting CL and HL and go flying North in front of me it's easy to think of what the quad will do in CL. Right stick back, it comes back south toward me. If I fly behind myself and am now facing south and pull back on right stick, it doesn't come back to my direction, it keeps going south away from me. This is with the assumption you have not reset CL and HL in the air at a different location.
     
  20. bbfpv

    Joined:
    Feb 3, 2015
    Messages:
    3,744
    Likes Received:
    1,092
    Location:
    Long Island, NY
    Good tip Monte. If one thinks of CL like a giant wagon wheel laying on its side, with the center being where the quad is, and one of the spokes the direction the quad is pointing, it's pretty simple to figure out how to bring it home. The point of reference like a tree, building, etc makes it that much easier.

    edit: Disregard this post, I was thinking of HL when writing about CL.