[Robotgroup] Triangulation

[Paul Atkinson]

I had toyed around with using an IR source and a spinning mirror to transmit
a beacon. The beacon is modulated by the mirror position effectively sending
a different code for each "pie slice" of the area covered. If you have two
of these beacons at 2 adjacent corners of a space, you can use an IR
receiver on a mobile platform to determine where you are in the space.

Since you already have some extra compute horsepower available, this might
be do-able on a tight budget.

Paul

On Feb 1, 2008 5:22 PM, Paul Atkinson <pmatkinson at gmail.com> wrote:

> There is a system called NorthStar that used IR transmitters and receivers
> for indoor use. I think there was some recent news about Version 2 being
> used in a main stream product, possibly Wowwee toys or something. I doubt it
> would work well against sunlight.
> http://www.evolution.com/products/northstar/
>
> You might be able to do something similar for less money.
>
> Certainly not in the $40 range per this link:
> http://www.acroname.com/robotics/parts/R274-NS-PROJECTOR-KIT.html
>
> Buried wire systems have been used for defining yard perimeters and also
> have been embedded in floors, FWIW. I don't know if they can be modifed
>
> Paul
>
>
> On Feb 1, 2008 4:20 PM, Robo Al <sp-18561884 at ggsys.net> wrote:
>
> > Does anybody know any links or reference material
> > about non GPS triangulation?
> >
> > I would like to play with something within these
> > requirements:
> >
> > * open and closed spaces around 150'x100' max size (ie.
> >  a yard or inside a house)
> > * accurate to within 1 to 3 centimeters
> > * inexpensive. Hopefully sub $40 for parts.
> > * A computer or fast uC will be available to do the
> >  calculations so the $40 is just for sensors and I/O
> >  interfacing to the computer.
> >
> > I would imagine setting 3 or 4 radio beacons within my
> > fence posts, but I'm afraid I just don't know enough
> > about radio triangulation.
> >
> > Thanks,
> >
> > Alberto
> >
> >
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>