Re: [mowbot] Mowbot

Monta Elkins (Monta nospam at
Wed, 25 Sep 1996 09:24:25 -0400

Ron Woodward wrote:
> >Anybody got any ideas for a location technology,
> >accurate to 3cm over 50M (without and dead reckoning
> >input)?
> >maybe ultrasound or IR beacons?
> If we used IR beacons and triangulation 3cm at 50m would
> require an angular resolution of 0.035 degrees
> Inv sin(.03/50). Doable but not for under 500$
> Would we need 3cm resolution? If we could get it we would
> not need any other kind of navigation which would be nice.

Yeah; would be nice...
I was thinking that if we could locate to 3 cm we wouldn't
have to worry too much about slipping drive wheels on wet
grass or steering over bumps or much of anything related
to streering/drive contact. But it looks like its too
much to hope for.

> But, How about say 1m resolution and suppliment it with
> near field sensing and navigation. Use the navigation
> beacons to get close and nearfield landmarks to tune us in.

That sounds like an good idea. Although I'd really like
to get resolution to .5 meter for yard boundary conditions.

> 1M resolution would only require 1degree resolution which
> can be done on the cheep. The accuracy could be improved
> if we were willing to use many IR beacons. This would bring
> up potiential problems with cost and maintenance or the
> beacons.

Beacons would be 'cheap and easy' right?
Just modulated IR on a stick?
You could power them battery, solar, or buried cable
like yard lights.

How many do we need? 3 always visible?

-Monta Elkins

| "All that is necessary for evil to triumph is |
| for good men to do nothing." -- Edmund Burke |
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