MicroMouse is a robotics competition where small, self-contained robots attempt to map, then solve and navigate a previously unseen maze.

What is MicroMouse?

MicroMouse is a robotics competition where small, self-contained robots attempt to map, then solve and navigate a previously unseen maze.

The robots, or mice, have to find their way from a certain pre-chosen corner cell to one of the center four cells of the maze, in the fastest possible time. To achieve this, they are allowed to make as many runs from the start cell to the finish cell as they can fit within a 10-minute timeslot.

The MicroMouse maze

A competition standard MicroMouse maze contains 16 cells north-south, and 16 cells east-west.  Each maze cell is 180mm x 180mm including the walls, with a maximum space of 168mm gap in between walls. The walls are 12mm thick, and are painted white, with a red top. The floor of the maze is painted with a non-reflective black paint.
 
The walls are attached to the baseboard using pegs at the junctions between walls.  The rules specify that each peg must have at least one wall adjoining it.

The different types of MicroMouse robots

There are two main species of MicroMouse in the UK MicroMouse competition, both of which run in their own separate class. They are the Wall Follower and the Maze Solver. 

Wall Follower

A Wall Follower is the simplest type of MicroMouse, and can often work effectively without any kind of control circuitry.  In fact, some of the most effective Wall Followers in recent years have consisted of a single motor attached to a battery, set up in such a way that the mouse hugs the wall. Wall followers, as the name suggests, solve the maze by following the left hand wall until the center is reached.  While this is a very simple way to find the way out of a maze, it is useless in most competition mazes, as they are likely to contain an island in the middle of the maze, meaning a wall following mouse will follow the left hand wall, and end up back where it started without even touching the center cell! Wall followers will usually only make a single run in competition, as they mostly have no intelligence, so will not know to go any faster on successive runs.

Maze Solvers

Maze Solvers are usually vastly more complicated than wall following mice, containing one or more microcontrollers and multiple perceptive (outward looking) and proprioceptive (inward looking) sensors.  In competition, a maze solver will normally make multiple runs, the first few to create a map in memory of the maze’s layout, and then runs at increasing speeds to attempt to attain the fastest speeds possible.

Normally, a mouse will only continue mapping until it has discovered enough of the maze’s layout to find the shortest or fastest route, and then switch over to speed mode.

When in the second mode, the mouse will normally make a series of runs from the start to the finish cells, possibly down different routes, and at increasing speeds, until it either runs out of time, or crashes.