Comment by dbcurtis | Hacker News Reader

Comment by dbcurtis | Hacker News Reader

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Yes, still going. The top competitors are wicked fast. When micromouse started, you could get an 8-bit microcontroller with a 1 MHz clock and just squeezing all the hardware into the footprint was a challenge, and having enough ram to represent the maze. Now you can easily make a small, fast, 32-bit ARM Cortex mouse that is small enough to take diagonal zig-zag portions of the maze in a straight line.

The maze is painful to set up, though. Our local robot club got together and a bunch of us each bought a kit that allows building a 5x5 maze, which is good for training. We can construct an "official-ish" 16x16 for competitions. I've been involved in set-up/tear-down a couple of times, and it is royally annoying and time consuming.

A quicker maze that is much more portable, and in terms of software, a conceptually identical software challenge (until you reach the level of diagonal short cuts) is to use electrical tape on linoleum floor tile to build a wall-less line-following maze. In the US, cheap lino floor tile comes in 12 inch squares. Cheap black electrical tape is 3/4 inch wide. We make a line-following maze out of that. It is quick to set up and tear down, and provides a good challenge for getting started in robotics. Linoleum tile is surprisingly heavy to cart around, but it is not unwieldy. It is totally practical to take a few minutes before a club meeting to deal out a random maze, which no way can be said for an official micromouse maze.

[edit] found a link to our rules http://slideplayer.com/slide/9202003/

> it is royally annoying and time consuming.

16x16 would be.. 15x16x2 moveable boards, then whatever you've got around the outside. I was wondering if you could maybe automate that with simple motors or electromagnets or somesuch, but I guess that would be quite complicated and potentially expensive to pull off.

New challenge: A robot to assemble a given maze as fast as possible.

Well, actually, you could build a swarm of 8 or so robots that are wall segments, and just have them scurry around dynamically constructing the part of the maze that is around the maze-solving robot.

> until you reach the level of diagonal short cuts

Why can't you make diagonal shortcuts on the tape-bounded maze? Is it just more difficult to verify that the mouse hasn't illegally cut a corner over the top of the tape?

Yes, basically. Without walls, you really arent't solving the same obstacle avoidance and navigation problem. The line following maze is the same search problem, but not the same sensor-integration/locomotion problem.

Ah, line-following. I assumed you were just replacing the walls with tape 'walls' that the mice could roll across but were not permitted to do so, and using outrigger sensors to detect and react when the mouse 'bumped' into a wall.

> royally annoying and time consuming

That should be an additional competition... maze setup and teardown robots.

:)

perfect application for a 3d printer table style. the resolution doesnt have to be perfect

Why does it take so long to set up? It seems like a pegboard (that possibly breaks down into several parts) and a bunch of pegged wall segments would allow one person to set up a 16x16 board in a few minutes.

Well, depends on your definition of "a few minutes". Here is what we did:

There is a company (I forget who) that sells kits of walls and pegs that meet the official Micromouse specifications. Each kit builds a 5x5 maze, good for debugging. With 9 of those, you can build a full maze. The walls meet the precise dimensional specification, wall color (white) and reflectivity (must reflect IR), and have a red stripe on the top (Micromouse allows cameras with a limited field of view to look at wall tops.) The pegs fit in 7mm holes. We got 16 people to buy a total of 18 kits, on the assumption that we could usually round up 9 people when we needed to construct an official maze.

A member identified a material call MDO (medium density overlay, I believe) that is basically an MDF board with a smooth laminate top. It is used for highway signage and such, and can be obtained at the lumber yard by special order. The surface has a smooth finish and takes paint well. A member was put in charge of finding paint that matched the floor specification, flat-black, must absorb IR.

The Techshop was still in business then, so three of us that were members used the Shopbot (CNC router with 4 foot by 8 foot table) to cut panels of the precise dimension required to do a 1/2 of a 5x5 maze, and pocketed a grid of 7mm holes at the correct spacing. Without CNC, it would be impossible to hold the spacing precisely enough, I think. So with two panels and one kit, you can build a 5x5.

It takes 4 to 6 man hours to set up a full 16x16 maze. It requires a flat surface. One thing we are missing is a way to keep all of the edge transitions between panels precisely level. That is a big problem. Our maze simply doesn't cut it for "world class" competitions. Luckily, we usually don't have world-class speed-daemon robots show up, so we can have a referee wearing socks stand in the maze trying to keep the edges from screwing up peoples runs.

Overall an interesting exercise, but the line following maze is much more practical to move around and set up, and gets used far more.

16x16 tiles is 256 tiles. Doing 256 of anything is time-consuming, let alone referencing a map and trying to make sure you do it right.

Sure, but I feel like I could place 256 Lego bricks, say, in 15 minutes or less, and a structure like this could be made as easy to assemble as Legos.

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