The Micromouse Competition

(with thanks to many previous rule masters worldwide)

Object: In this contest, the contestant or team of contestants must design and build small self-contained robots (micromice) to negotiate a unconnected maze from an outside corner to the middle in the shortest possible time without crashing. Since its invention at MIT in 1979, the micromouse competition has been one of the ultimate challenges for robot enthusiasts, sort of the Nascar Circuit of the robot world.

Class A: Competition follows the official micromouse rules.

Class B: Competition also follows the official micromouse rules, but designers are invited to cheat in any way they can think of that does not damage the maze.


Contents of this page:


Competitor Design Parameters: Micromouse

Class A Competition: (Adapted from the 1986 RULES for the NORTH AMERICAN MICROMOUSE)

 

  1. A micromouse shall be self-contained (no remote controls). A micromouse shall not use an energy source employing a combustion process.
  2. A micromouse shall not leave any part of its body behind while negotiating the maze.
  3. A micromouse shall not jump over, fly over, climb, scratch, cut, burn, mark, damage, or destroy the walls of the maze.
  4. A micromouse shall not be larger, either in length or in width, than 25 centimeters. The dimensions of a micromouse which changes its geometry during a run shall not be greater than 25cm x 25cm. There are no restrictions on the height of a micromouse. The base of the mouse must travel on the floor, not on the tops or sides of the walls.

Maze Platform Details

The maze is composed of multiples of an 18cm x 18cm unit square. The maze comprises 16 x 16 unit squares (see examples below). The walls of the maze are 5cm high and 1.2 cm thick (with a plus-or-minus 5% tolerance.) The outside wall encloses the entire maze.

The maze may consist of any combination of "L", "T", "J", "+", and straight ("I") sections. NOTE: There may be unit squares NOT bounded by walls, allowing crossing paths with the "+" combination.

 

     _______________________________ 
    |  _________________________    |
    | |    _.  _  |_  ____________| |
    | | |_   _  |_  |_____       _| |
    | |_  |_  |_  | |  _____| |_  | |
    | | |_  |_  |_  |_____.  _|  _| |
    | |   |_  |_  |_| ._. |_  |_  | |
    | | |_  |_  |_____   _|  _|  _| |
    |  ___|_____| | F | |  _| |_  | |
    | | . |   | |  ___|  _| | |  _| |
    | | | | | | |_______| | | |_  | |
    | | | | | | | |  _____| | |  _| |
    | | | | | | | | |  _____| |_  | |
    | | | | | | |   | |  _____|  _| |
    |   | | | | | | | |   |   |_  | |
    | | |___|___| | | | |___|_____| |
    |S|_____________________________|
   From: 1990 APEC Maze (L.A. 3/141982

     _______________________________ 
    |___    |   | |   |     |  ___  |
    |  _  |  _|_  | | | | |     |   |
    |   | |     | | | | | | | | | | |
    | |_| |_|_|_   _|_____| | |_  | |
    |   |___|_  |_|        _|_  |___|
    |_| | __  __| | | | |  ___|___  |
    |  _|_________|___|_|___  |  _  |
    |  _________|   F |  ___  |_  |_|
    | |  _____  | |___|___      |   |
    | | |_____  | | |   | | |_|_  | |
    | |  _  __|___|  _|   |  _  |   |
    | |_|_______________|___|_  | | |
    | |___    |  _  | |  ___  |_|_  |
    |  _  | |___| | __|_______  | | |
    | | | |   | ____  |___     _|_  |
    |S|_____|_______|_______|_______|
       From: Chicago, 1986 (26 sec.)

Sample Legal Micromouse Mazes from previous competitions

The start of the maze is located at one of the four corners. The mouse shall begin negotiating the course in a clockwise direction. (The start square is bounded on three sides by walls, with the exit facing clockwise.) At the center of the maze, there is a central square which is composed of four unit squares. This central square is the destination. At the center of this square is a red post, 20cm high and each side 2.5cm, which may be removed if requested. The destination square has only one entrance.

Small square zones, each 1.2cm x 1.2cm at the four corners of each unit square are called lattice points. The maze is so constituted that there is at least one wall at each lattice point, except for the destination square. Walls are removable and replaceable.

The sides of the maze walls are flat white arborite, the tops of the walls gloss red electrical tape, and the floor matte black arborite. The maze is made entirely of particle board or wood and kept as level as possible. As a result of construction irregularities, robot designers should note that the floor may have occasional cracks up to 2mm high and 2mm wide covered with standard black tape. these are the join edges between the base sections used to construct the maze.

For any particular maze setup, there may be sections of the maze which are completely closed off from micromouse entry.

Multiple paths to the destination square are allowed and are to be expected.

The illumination, temperature, and humidity of the room shall be those of an ambient indoor stage environment. Designers have the right to ask for reasonable considerations (i.e.: no camera flashes during the competitor run, clean running surfaces, etc.).

Race Procedure

Each contesting micromouse is subject to a time limit of 15 minutes. Within this time limit, the micromouse may try to make up to 10 runs. Scoring is designed to reward efficiency, self-reliance, and mouse intelligence. To the time of each mouse run is added one-thirtieth of the total run time elapsed. Thus a sixty second run achieved after five minutes on stage will score seventy seconds. If the mouse remains untouched by human hands, a ten-second bonus will be removed from each run. Thus, a mouse achieving a sixty second run after five minutes will score 60 + 2 x 5 - 10 = 60 seconds. Once touched, the subsequent runs are timed without bonus.

Each run shall be made from the start. The operator may abort a run at any time. If an operator touches the micromouse during a run, it is deemed aborted. When an operator aborts a run, the mouse must be removed from the maze immediately. (If a mouse has already crossed the finish line, it may be removed at any time without affecting the time of that run.)

After the maze is disclosed, the operator shall not feed information on the maze into the micromouse. Each mouse must begin the 15 minute time trial "cold".

The timer will start when the mouse crosses the start line and finish when the mouse crosses the finish line. The start line is at the open boundary between the starting unit square and the next unit square. The finish line is at the entrance to the destination square.

Every time the mouse leaves the start square, a NEW run begins (up to 10 runs). If the mouse has not entered the destination square, the previous run is aborted, as if the mouse were touched. For example, if a mouse re-enters the start square (before entering the destination square) on its first run, that run is aborted, and it will be on run #2 after exiting the start square again (an obvious malfunction resulting in the mouse moving into and out of the start square does not count against the maximum 10 runs).

The mouse may, after reaching the destination square, continue to navigate the maze, though if a mouse continues to navigate the maze after reaching the destination square, the time taken will not count toward any run. It will, however, count toward the total allowed time of 15 minutes. When the mouse next leaves the start square, a new run will start (a mouse can thus make several runs without being touched by the operator by making its own way back to the beginning for maximum bonus) The 15 minute timer will stop only when the mouse is touched and continue when the mouse starts its next run.

The judge reserves the right to ask the operator for an explanation of the micromouse. The judge also reserves the right to stop a run, declare disqualification, or give instructions as appropriate (i.e. if the structure of the maze is jeopardized by continuing operation of the mouse).

The Micromouse entry may be the effort of an individual or a team. In the case of a team, it should be possible to demonstrate that each individual made a significant contribution.

As mentioned, a contestant may not feed information on the maze to the micromouse in any way. The following do NOT violate this rule: Changing batteries between runs; Setting switches to alter algorithms (i.e. Stop/Search/Run); Adjusting sensors; Changing Speeds; Repairing. The following DO violate this rule: Changing ROM; Loading new programs: Changing sensors. The judges shall arbitrate, however, a contestant may not tamper with the mouse in a manner which alters its weight. (i.e. removal of a bulky sensor array to get better speeds after mapping the maze is not allowed.)

A single design team may enter more than one mouse, and each mouse is eligible for a prize. Mass-produced mice of nearly identical design will not be allowed.

In each contest, a maximum of one (1) break will be provided for each contesting mouse. The 15 minute time clock will stop. When the mouse is re-entered, the time will continue from the stopping point. The mouse must again begin at the start for a new run (up to 10, including the previous runs.) The mice shall re-enter the competition only after all other competitors have attempted the maze. They will be re-entered in the order in which the breaks were taken.

If no successful run has been made, the judges will make a qualitative assessment of the mouse's performance, based on distance achieved, intelligence of behavior (verses random behavior), and quality of control.

Micromouse: Class B Division

The rules are exactly the same as for the normal micromouse competition, however, during their runs, competitors are now allowed to cheat in any way that does not harm the maze, participants, audience, or local time-space continuum.

The reason for this division is to get a bit more innovation into the sport. For years now, the world champions have kept their leads by scant milliseconds over other competitors. Reaching, in effect, the optimal solution possible under the old rules and restrictions. This division will hopefully spark a variety of devices with interesting solutions (previous entrants along this line have included a cube which gave a very good philosophical argument that it was, for all intents and purposes, already in the center of the maze, and a machine that tried, unsuccessfully, to leap into the maze middle from the start square).

Special awards will, of course, be presented.


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