Newsgroups: comp.robotics
Path: brunix!news.Brown.EDU!noc.near.net!howland.reston.ans.net!torn!watserv2.uwaterloo.ca!watmath!mwtilden
From: mwtilden@math.uwaterloo.ca (Mark W. Tilden)
Subject: Re: Lawn Bot
Message-ID: <C8Cw1D.41o@math.uwaterloo.ca>
Sender: news@math.uwaterloo.ca (News Owner)
Organization: University of Waterloo
References: <Brian_Sullivan.38@Carleton.CA>
Date: Wed, 9 Jun 1993 13:27:12 GMT
Lines: 42

In article <Brian_Sullivan.38@Carleton.CA> Brian_Sullivan@Carleton.CA (Brian_Sullivan) writes:
>I've been waiting for this one for a few years now. The other day in 
>Harowsmith I saw an ad for a (lack af a better name) lawn bot. The robot
>runs on solar power, and cuts the grass. If if runs into something, it
>backs up ..... 'put it out in the spring and take it in the fall'. 
>
>Dont suppose it would clear the walk in the winter?
>
>Not my copy of the mag so I don't know more. Has anyone else heard of this
>and have any details?

Saw one just two weeks ago at the Brussels Alife conference.  The device
uses 7% efficient solar cells that allow it to move but don't give it
much power, so it uses a cool algorithm to 'nibble' at the grass in a 
closed area to guarentee it never stalls the cutting blade.  It has a 
set of forward sensors which overide it's explore commands if it ever 
encounters a white rope about 3mm thick.  Line your lawn with this stuff 
and the critter won't munch your daisies or go for a stroll down the walk.

It uses two 6" wheels for motivation and some standard stepper motors
through a gearbox for longevity.  The processor is oure olde frende the 68HC11
well sealed against the environment.  It comes in two parts of shiny green
fiberglass joined in the middle, back peppered with solars, 8" high, oblong
and about a meter at its max dimension.

Travels about a meter a second under full sunlight.

Quiet and functional, but no provisions for complex terrain.  Can get 
jammed very easy.  Also very fragile.  The fiberglass body is the main 
support structure and it flexes alarmingly over even minor potholes.
The solars are mounted below a sheet of plexi but even still, one good
cat attack, lawn dart, volleyball, or misplaced step and you're out an 
expensive toy.

Is all.


-- 
Mark W. Tilden.  "Gomi no Sensei des"       _    _    ________________________
MFCF, Un. of Waterloo, Ontario, Canada.    / \  / \  /________________________)
519/885-1211 <mwtilden@math.uwaterloo.ca> //\ \//\ \// ___o___________________
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