Walls and Slots - was Re: APEC Rules

[Peter Harrison <peter_harrison@ntlworld.com>]

David Otten wrote:
> "see".  Since the post is the last thing the sensors see before an open 
> square, there is a chance that the slot confuses the mouse if the 
> designer is not thinking about it.

And that is the key (so to speak) The plastic maze walls available in SE 
Asia and now in the UK and elsewhere have these large slots in them.

Slots between walls and posts of up to 1mm or so [as in the rules] are 
pretty well inevitable unless you can construct a maze to extremely good 
tolerances. Actual slots may wel be bigger.

I worried for a while about making a really good maze until I realised 
that it was pretty pointless. If I could not get my mouse to run in a 
rough and ready maze, I would be designing it for an ideal, controlled 
environment that may exist nowhere else in the world.

When testing, I sometimes just stand walls up deliberately out of place, 
or at an angle or even place another wall inside the existing walls to 
create a kind of chicane.

It is the designers responsibility to try and make the beast work under 
the worst possible conditions. There is no fun or gain in complaining 
because a mouse did less well due to the gaps being 0.25mm over size.

As they stand the rules make no mention of the slots, only gaps between 
walls. But be honest - how many of you can detect the slots anyway? Tony 
had trouble with resonant cavities for ultrasound. Dave mentioned a tiny 
beamwidth for his sensors but still only shows the slots as a drop of a 
few percent. My sensors throw an 8 degree beam which would be 15mm 
across at the wall - I cant tell they are there. In any event, you 
should have some idea where you are - compensate for when you expect to 
be looking at a post or gap.

Take the issue of steps between parts of the maze floor. Fail to take 
them properly into account and your mouse could be left with its wheels 
in the air. My current mouse can handle a 1mm step [as in the rules] but 
gets stranded on a 1.6mm step. That will have to be improved before I 
run in a 'real' maze - just in case.

Pete Harrison
http://micromouse.cannock.ac.uk/