Magnetic ompass controlled servo and rudder

Discussion in 'The Projects Forum' started by Daemon, Jul 10, 2011.

  1. Daemon

    Thread Starter Active Member

    Jun 20, 2009
    33
    0
    Hi

    I am trying to achieve the same as demonstrated on tuckertiki.co.nz in the example video for my kontiki

    It is a device that you simply point it in the direction you want it to head in then power it on at which time it locks in the heading and then as it heads out to sea as the heading changes the magnetic compass controlled servo changes the position of the rudder to compensate and get it back onto its heading.

    Does anyone have any suggestions for already completed gear that may do what I want?

    I can build the board and program a pic microcontroller with the firmware but I don't understand what equipment I will need to complete it.
    I have googled around and found magnetic compass modules and there are plenty of autopilots out there using arduino or picaxe but they all seem to have integrated gps as well.

    Thanks
    Steve
     
  2. debe

    Well-Known Member

    Sep 21, 2010
    946
    184
    Hi Steve heres some info on a simple tiller pilot i owned many years ago. It used a compas module with 2 LDRs picking up light through a compas card which was half black & other half clear to give direction control. Feed back to the compas was a spring loaded string wraped around the compas module. It used to work on a Yacht i used to have back in about 1980. these style of tiller pilots are still around but use fluxgate compases these days.
     
  3. Daemon

    Thread Starter Active Member

    Jun 20, 2009
    33
    0
    Thanks for that.
    This one has a weather vane as well correct?
    I have read about the flux compasses and think I can do something quite a bit simpler with a software solution and a simple pic.
    I will try to stick to that for now because it seems like a simpler solution.

    Cheers
    Steve

    Its amazing what they invent to steer yachts. Do they use these while they sleep? How do you avoid obstacles?
     
  4. debe

    Well-Known Member

    Sep 21, 2010
    946
    184
    Definitly dont sleep when on auto pilot, been plenty of boats wrecked due to not looking where going on auto. A nother model used 2 linear hall devices 180deg apart under the compas module, these sensed a change in magnetic strength of the compas magnet to give a linear output voltage to same type of circuit. Yes there was a wind vane atachment. Also one of the sections of the opamp sensed drive motor current, when the motor drive came to the end of stroke it shutdown power to motor to short pulses to protect the motor.
     
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