Re: [Autopilot] inherently stable designs

[Tramm H. <hu...@sw...>]

Bram Stolk wrote:
> To avoid problems with stability due to gyro inaccuracies,
> I think I will simply go for an inherently stable design.
> It will be a slow-mover, but a lot more stable in the air.
> 
>     P     P
>     -------
>        |
>        |
>        |
>        |
>        |
>        M
>               ^
>               |up
> __________________
> //////////////////

It seems that you would have the pendulum problems inherent in
sling loads.  If the large mass M swings slightly, it has an
enormous lever arm to push the much lighter props.

> (impossible to tumble over, and crash really hard)

Or would it be very likely to tumble over and crash really hard?
Let's say it sets down with a small amount of side drift.  The
large mass hits the ground and "sticks", causing a rapid rotation
about the lever arm and impacting the props into the carpet.

> Note: to keep the figure simple, I only drew 2 props, but it will have 4
> ofcourse. With experimentation I could slide M up and down, to find
> a good ballance between aerobatic prowess versus inflight stability.

My guess is that more stability would come from a wider base and
wider arms for the props.

> I'm curious what the experts (read: you guys) think of this.

Expert?  I can't even hover very long...

Trammell
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