Electronics and small lawnmower engines
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Does anyone have experience about what happens to electronics (basic stamp I
guess in this case) running "near" (say 1 to 3ft away from) a small 2 or 4
cycle lawnmower motor?
I can understand the magneto and magnetic forces can create havoc, (how much
exactly is out of my comprehension as I have never looked into it
specifically) And i understand that vibration would also have some factor.
(but again, how much is beyond me at this very moment)
But the reason I ask is I keep thinking about that TORO robotic mower, and I
cant think of a good enough reason (that a little money cant solve) that
application couldnt be better applied with a small gasoline motor, a gps, an
electronic compass of some type, maybe some IR sensors, or ultrasonic
rangefinders etc. to eliminate the short run times.
I am thinking something would be possible along the lines of opto-isolation,
RF shields of some type, lead shields maybe etc. etc.
How nasty a project could it be? Its just an Idea. Any Thoughts?
Dan
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guess in this case) running "near" (say 1 to 3ft away from) a small 2 or 4
cycle lawnmower motor?
I can understand the magneto and magnetic forces can create havoc, (how much
exactly is out of my comprehension as I have never looked into it
specifically) And i understand that vibration would also have some factor.
(but again, how much is beyond me at this very moment)
But the reason I ask is I keep thinking about that TORO robotic mower, and I
cant think of a good enough reason (that a little money cant solve) that
application couldnt be better applied with a small gasoline motor, a gps, an
electronic compass of some type, maybe some IR sensors, or ultrasonic
rangefinders etc. to eliminate the short run times.
I am thinking something would be possible along the lines of opto-isolation,
RF shields of some type, lead shields maybe etc. etc.
How nasty a project could it be? Its just an Idea. Any Thoughts?
Dan
_________________________________________________________________
Get your FREE download of MSN Explorer at http://explorer.msn.com
Comments
your gropund traces as large as you can, split up analog and digital
ground paths if your design allows it, sprinkle a .1uF under the
power pins of every chip. Use sheilded cable for the high impedance
interconnects, (Don't ground both ends of any sheilded cable you may
use) Enclose the electronics in a metal, grounded Bud Box.
What I do: I grab an old electric drill (with WORN brushes) the
brushes are worn and sparks come out the side of the thing. I run the
drill close to my project and see what happens, I also subject my
project to RF, I use an old CB and small whip..
If my breadboarded project survives the drill and CB tests it usually
does OK when it is transferred to a PCB.
CUL8TR
Rich
--- In basicstamps@y..., "Dan g" <damage31@h...> wrote:
> Does anyone have experience about what happens to electronics
(basic stamp I
> guess in this case) running "near" (say 1 to 3ft away from) a small
2 or 4
> cycle lawnmower motor?
> I can understand the magneto and magnetic forces can create havoc,
(how much
> exactly is out of my comprehension as I have never looked into it
> specifically) And i understand that vibration would also have some
factor.
> (but again, how much is beyond me at this very moment)
>
> But the reason I ask is I keep thinking about that TORO robotic
mower, and I
> cant think of a good enough reason (that a little money cant solve)
that
> application couldnt be better applied with a small gasoline motor,
a gps, an
> electronic compass of some type, maybe some IR sensors, or
ultrasonic
> rangefinders etc. to eliminate the short run times.
> I am thinking something would be possible along the lines of opto-
isolation,
> RF shields of some type, lead shields maybe etc. etc.
> How nasty a project could it be? Its just an Idea. Any Thoughts?
> Dan
>
> _________________________________________________________________
> Get your FREE download of MSN Explorer at http://explorer.msn.com
>Does anyone have experience about what happens to electronics (basic stamp I
>guess in this case) running "near" (say 1 to 3ft away from) a small 2 or 4
>cycle lawnmower motor?
>I can understand the magneto and magnetic forces can create havoc, (how much
>exactly is out of my comprehension as I have never looked into it
>specifically) And i understand that vibration would also have some factor.
>(but again, how much is beyond me at this very moment)
>
>But the reason I ask is I keep thinking about that TORO robotic mower, and I
>cant think of a good enough reason (that a little money cant solve) that
>application couldnt be better applied with a small gasoline motor, a gps, an
>electronic compass of some type, maybe some IR sensors, or ultrasonic
>rangefinders etc. to eliminate the short run times.
>I am thinking something would be possible along the lines of opto-isolation,
>RF shields of some type, lead shields maybe etc. etc.
>How nasty a project could it be? Its just an Idea. Any Thoughts?
I'd be inclined to start with a desk check of the proposed navigational
system. You can do a simple sanity check on use of GPS as your main
position sensor. Read the specs for your GPS unit and determine the total
error and convert that into feet. Be sure to use the error factors
applicable when the GPS unit is not stationary, but must grab position on
the fly. If GPS still looks good, then add any Stamp conversion
errors. Now you can make a tentative Go or a definite No-Go decision on GPS.
Note that the TORO navigates (stays on its own property) using a buried
perimeter wire. Mowing pattern is triangular after it first mows the
perimeter. The guided tour at
http://www.toro.com/home/mowers/imow/index.html implies the triangular
pattern is nearly random. Maybe I missed something, or took the mowing
pattern their demo displayed too literally, but the Toro iMow seems more
persistent than intelligent.
How nasty could this get? You got neighbors? Consider the liability
issues and be prepared to deal with them in your design.
Jim H
HigginsJ@sc.rr.com writes:
Very astute point -- and dead on. ·Don't get me wrong...I used to work for
Toro (13 years), still own stock and want them to be wildly successful, but
the "algorithm" in that mower fits your description better than theirs.
-- Jon Williams
-- Dallas, TX[/font]
>In a message dated 5/25/01 4:45:38 PM Central Daylight Time,
>HigginsJ@s... writes:
>
>
>>but the Toro iMow seems more persistent than intelligent.
>
>
>Very astute point -- and dead on. Don't get me wrong...I used to work for
>Toro (13 years), still own stock and want them to be wildly successful, but
>the "algorithm" in that mower fits your description better than theirs.
Thanks for confirming. For my part it wasn't meant as a slam on Toro, just
a neutral observation. The thing's too rich for my taste, but it does look
pretty neat. And if someone were to give me one (hint, hint) I wouldn't
care if it mowed inefficiently as long as it got the job done.
Jim H
mower is almost as efficient as a fixed pattern, and leaves a better looking
mow job. And it's certainly seems a whole lot easier to program!
Michael
>>but the Toro iMow seems more persistent than intelligent.
>Very astute point -- and dead on. Don't get me wrong...I used to work for
>Toro (13 years), still own stock and want them to be wildly successful, but
>the "algorithm" in that mower fits your description better than theirs.
>I remember reading somewhere that a "random" algorithm for an automatic
>mower is almost as efficient as a fixed pattern, and leaves a better looking
>mow job. And it's certainly seems a whole lot easier to program!
I think the choice of a random pattern would have been determined more as a
side effect of the available control and navigation precision rather than
the ease of programming, but I could be wrong.
For sure I can't imagine random even coming close to a carefully controlled
pattern for efficiency. Imagine a yard that is all done except for one
little 1-foot square patch placed somewhere at random. I'd have to say
chances are excellent that a random mower would probably remow 90% of the
yard before finding this patch. That would be very inefficient. And a
random mowing pattern could tend to leave many such patches. (They do
mention a tiny bit of touching up may be needed after iMow is done. But
the real bottom line seems to be... who cares as long as the battery lasts
and you don't have to walk behind it? ;-)
Jim H
few months back. I concluded that GPS was not the perfect solution for a
clutterd lawn. The resolution of GPS was around 9 feet approximatly, unless
an external radio signal was also used for calibration. The combination of
the 2 signals seemed to be to much hastle, I decide a single radio system
and triangulation would be a better method. However I am not knowledgable
enough to implement this. I had also planned to use a Dog collar radio fence
around the perimiter of my yard. These are very accurate and sure work fine
for my dog. I can set whatever range I wish from the buried wire. You can
also make zones around large areas. such as the house itself using the
buried wire. This would then leave the small items, such as flower gardens,
and trees, to be avoided.
I myself have not gotten any further with these ideas. I only wanted a
wandering robot. But attaching a mower deck is the easy, and final step.
At 04:39 PM 5/26/2001 -0400, you wrote:
>At 09:08 05/26/01, Michael Clark wrote:
>
>>I remember reading somewhere that a "random" algorithm for an automatic
>>mower is almost as efficient as a fixed pattern, and leaves a better looking
>>mow job. And it's certainly seems a whole lot easier to program!
>
>I think the choice of a random pattern would have been determined more as a
>side effect of the available control and navigation precision rather than
>the ease of programming, but I could be wrong.
>
>For sure I can't imagine random even coming close to a carefully controlled
>pattern for efficiency. Imagine a yard that is all done except for one
>little 1-foot square patch placed somewhere at random. I'd have to say
>chances are excellent that a random mower would probably remow 90% of the
>yard before finding this patch. That would be very inefficient. And a
>random mowing pattern could tend to leave many such patches. (They do
>mention a tiny bit of touching up may be needed after iMow is done. But
>the real bottom line seems to be... who cares as long as the battery lasts
>and you don't have to walk behind it? ;-)
>
>Jim H
>
>
>
>
>Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
>
Sincerely
Kerry
Admin@M...
WWW server hosting [url=Http://mntnweb.com]Http://mntnweb.com[/url]
Kerry Barlow
p.o. box 21
kirkwood ny
13795
there again.
The ideal mower would use a different pattern each time it mowed, so there
would be no wheel ruts in the yard -- ie across one time, up and down the
next, diagonal, etc...
I really think an unattended mower would be a bad thing, especially if you
have curious kids in the neighborhood. I would put some sort of proximity
sensor on it to shut the thing off if a person was near.
Original Message
> >I remember reading somewhere that a "random" algorithm for an automatic
> >mower is almost as efficient as a fixed pattern, and leaves a better
looking
> >mow job. And it's certainly seems a whole lot easier to program!
>
> I think the choice of a random pattern would have been determined more as
a
> side effect of the available control and navigation precision rather than
> the ease of programming, but I could be wrong.
>
> For sure I can't imagine random even coming close to a carefully
controlled
> pattern for efficiency. Imagine a yard that is all done except for one
> little 1-foot square patch placed somewhere at random. I'd have to say
> chances are excellent that a random mower would probably remow 90% of the
> yard before finding this patch. That would be very inefficient. And a
> random mowing pattern could tend to leave many such patches. (They do
> mention a tiny bit of touching up may be needed after iMow is done. But
> the real bottom line seems to be... who cares as long as the battery lasts
> and you don't have to walk behind it? ;-)
>
> Jim H
>
>
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
>
expense in implementing a navigation system with the accuracy to resume the
planned path after avoiding unexpected obstacles without leaving a "shadow"
of un-cut grass.
My reasoning on the random method is that while the mowbot may leave an
um-mowed spot today the probability that it would miss the same spot
tomorrow is extremely low. Therefore over a period of time the entire yard
would get mowed.
I wrote a VB program a while back for simulating the random method. This
program demonstrates that the entire yard is indeed covered over a period of
n passes. This also shows that as you try more complex (real world) yard
layouts there are other issues that come up. Anyone interested in this
program can email me at michael@a... NOT the list (we don't want to
upset anyone) and I can email it to you.
Mike
Original Message
From: Rodent [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=LQWCL0Qb_BQGvyw0qc1t72Gnw-mTf8b0hOGcnDj3RmDF92kNLTor9X0eTjMi6HvKOKq9gt5PZW4uiR0m]daweasel@s...[/url
Sent: Monday, May 28, 2001 4:03 PM
To: basicstamps@yahoogroups.com
Subject: Re: [noparse][[/noparse]basicstamps] Electronics and small lawnmower engines
The random bit would only work if it knew where it had been and didn't go
there again.
The ideal mower would use a different pattern each time it mowed, so there
would be no wheel ruts in the yard -- ie across one time, up and down the
next, diagonal, etc...
I really think an unattended mower would be a bad thing, especially if you
have curious kids in the neighborhood. I would put some sort of proximity
sensor on it to shut the thing off if a person was near.
Original Message
> >I remember reading somewhere that a "random" algorithm for an automatic
> >mower is almost as efficient as a fixed pattern, and leaves a better
looking
> >mow job. And it's certainly seems a whole lot easier to program!
>
> I think the choice of a random pattern would have been determined more as
a
> side effect of the available control and navigation precision rather than
> the ease of programming, but I could be wrong.
>
> For sure I can't imagine random even coming close to a carefully
controlled
> pattern for efficiency. Imagine a yard that is all done except for one
> little 1-foot square patch placed somewhere at random. I'd have to say
> chances are excellent that a random mower would probably remow 90% of the
> yard before finding this patch. That would be very inefficient. And a
> random mowing pattern could tend to leave many such patches. (They do
> mention a tiny bit of touching up may be needed after iMow is done. But
> the real bottom line seems to be... who cares as long as the battery lasts
> and you don't have to walk behind it? ;-)
>
> Jim H
>
>
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
>
Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
image -- eventually it blanks out everything.
Original Message
> I would believe that the random method is used due to the difficulty and
> expense in implementing a navigation system with the accuracy to resume
the
> planned path after avoiding unexpected obstacles without leaving a
"shadow"
> of un-cut grass.
>
> My reasoning on the random method is that while the mowbot may leave an
> um-mowed spot today the probability that it would miss the same spot
> tomorrow is extremely low. Therefore over a period of time the entire
yard
> would get mowed.
>
> I wrote a VB program a while back for simulating the random method. This
> program demonstrates that the entire yard is indeed covered over a period
of
> n passes. This also shows that as you try more complex (real world) yard
> layouts there are other issues that come up.