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ACM Position Hold

Posted by Jason Short on February 13, 2011 at 8:00pm

This is my first successful flight with a good alt hold and good GPS hold. As soon as I can demonstrate a fully autonomous flight (codes already done, just not flight tested enough), I'll release the Alpha. 

 

BTW, the wind was about 5mph West which was causing the forward and back oscillation. I had the I term disabled, so it never accounted for the wind. 

 

Jason

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Comments

  • Christof Schmid February 14, 2011 at 12:47am

    Jason, thats awsome.

    What we will need is a sensor to make sure the craft is not going below a certain distance to ground. Maybe 1m.  Thats where I got nervous and broke a leg. Or just flying a bit higher ;-)

    Christof

     

  • Ground Loop February 13, 2011 at 8:54pm

    John C:  You will want to be high up and away from obstructions.  Hover in Stable mode, one position.

    Then engage GPS Hold.  It should hold it in the same area of the sky.  I find I have to manage the altitude more than the X/Y position.

     

    If you move the craft away from the origin, it will go back to Home when you release the cyclic... pretty aggressively too.

     

    Note that you have very little input into altitude, so you will have to hold it for some time before it takes effect.  This is why you want to start with plenty of headroom.

     

    Always be prepared to center the sticks and take it back from GPS Hold to Stable.  Make sure you have a magnetometer calibrated and working, and have also removed the motor "Safety" feature from the code (my tip).

     

    Do not try GPS Hold from the ground!  You need some altitude to work with.

  • John D. February 13, 2011 at 8:50pm

    Looks great!

  • John C. February 13, 2011 at 8:46pm

    I'm still skittish about turning this on...(as I should be)....a couple of questions.

     

    I've seen the solid red LED now with GPS lock.  I assume I need that on for this to work?

     

    When I turn it on sitting on the ground, I get a third throttle, but not enough to take off, and the throttle stick does NOTHING.  (I know this is NOT how I'm supposed to do it, but baby steps)  Should I have throttle control at the stick when in this mode?

     

    I assume I go into and out of Pos_hold from Stabilize, and that 2+ meters is enough room?

     

    FBW has been working well for me.  It's a little more twitchy than stabilize, but works well.

     

    Thanks for the work Jason.  Really enjoying messing with this.

     

    JC

  • 3D Robotics
    Chris Anderson February 13, 2011 at 8:14pm
    Astounding. Much better than what we achieved with ArduCopter RC2.
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