Re: [mowbot] A modest proposal

robin nospam at
Fri, 27 Sep 1996 00:58:07 +0100

"Dana Gould" <dgould nospam at> wrote:
> I think there are two dimensions to the problem.
> 1) lawn size
> small size - less than 1/2 acre
> medium size - 1/2 to 1 acre
> large size - 1 to 2 acres
> very large - more than 2 acres
> 2) lawn topography
> low complexity - flat or almost flat, few or no obstacles
> medium complexity - modest slopes, some obstacles
> high complexity - hilly, many obstacles

Isn't 2) in fact measuring two uncorrelated things: hilliness and
number of obstacles?

My lawn would be categorised as small size, flat, few obstacles.
But to take that as the basis for the design would be too boring:-)
And what would I do if I moved, or wanted to build a Mowbot for a friend?
Instead, I have been thinking and talking about designs that will cope
with the explicit size requirement of 1 acre (called ``medium'' above,
though I must say I thought that was quite large when I set it as the size
limit) and the implicit assumptions of hilly, medium to high complexity.

> As lawn size grows, then power requirements would
> grow. Battery operation would be less practical
> as you go from small to medium to large lawns. I
> suspect from large to very large lawns, gas power
> would become more practical.
This neglects the very interesting possibility that several Mowbots could
share the work on a large area.

> (For the purpose of this discussion I'm defining
> navigation as "where am I now" and guidance as
> "which way do I go now".)
This is a good and succinct way of describing these two aspects.

> I hope this helps the discussion by giving a
> simple framework to some of the various problems
> and proposed solutions.
It certainly does. Can other people chip in with their own estimates
of size/hilliness/obstacles so we can see if we are being too ambitious
(or not sufficiently ambitious)?

> Sorry if I sound a little pedantic, I get that way sometimes. :)
Sounds like we'll get along just fine!


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