Micromouse

revised 1-1-07

Object

The object of the contest is to build a robot that can negotiate a specified maze in the shortest time. A robot participating in this contest is termed a MicroMouse. The person who places the MicroMouse in the maze and starts its operation is termed a handler.

I. Specifications for the Maze

  1. The maze shall comprise 16 x 16 multiples of an 18 cm x 18 cm unit square. The walls constituting the maze shall be 5 cm high and 1.2 cm thick. Passageways between the walls shall be 16.8 cm wide. The outside wall shall enclose the entire maze.
  2. The sides of the maze walls shall be white, and the top of the walls shall be red. The floor of the maze shall be made of wood and finished with a non-gloss black paint. The coating on the top and sides of the walls shall be selected to reflect infrared light and the coating on the floor shall absorb it.
  3. The start of the maze shall be located at one of the four corners. The starting square shall have walls on three sides. The starting square orientation shall be such that when the open wall is to the ‘north,’ outside maze walls are on the ‘west’ and ‘south.’ At the center of the maze shall be a large opening, which is composed of 4 unit squares. This central (4-unit) square shall be the destination.
  4. Small square posts, each 1.2 cm x 1.2 cm x 5 cm high, at the four corners of each unit square are called lattice points. The maze shall be constituted such that there is at least one wall touching each lattice point, except for the destination square.
  5. The dimensions of the maze shall be accurate to within 5% or 2 cm, whichever is less. Assembly joints on the maze floor shall not involve steps of greater than 0.5 mm. The change of slope at an assembly joint shall not be greater than 4 degrees. Gaps between the walls of adjacent squares shall not be greater than 1 mm.

II. Specifications for the MicroMouse

  1. A MicroMouse shall be self-contained. It shall not use an energy source employing a combustion process. It shall be fully autonomous, in no way receiving any external control or data during the contest.
  2. The length and width of a MicroMouse shall be restricted to a square region of 25 cm x 25 cm. The dimensions of a MicroMouse that changes its geometry during a run shall never be greater than 25 cm x 25 cm. The height of a MicroMouse is unrestricted.
  3. A MicroMouse shall not leave anything behind while negotiating the maze.
  4. A MicroMouse shall not jump or climb over the walls of the maze. It shall not scratch, damage, mark, discolor or destroy the walls or floor of the maze.

III. Rules for the Contest

The basic function of a MicroMouse is to travel from the start square to the destination square. This is called a run. The time it takes is called the run time. Traveling from the destination square back to the start square is not considered a run. The total time from the first activation of the MicroMouse until the start of each run is also measured. This is called the maze time. If a MicroMouse requires manual assistance at any time during the contest it is considered touched. By using these three parameters the scoring of the contest is designed to reward speed, efficiency of maze solving, and self-reliance of the MicroMouse.

  1. The scoring of a MicroMouse shall be done by computing a handicapped time for each run. This shall be calculated by adding the time for each run to 1/30 of the maze time associated with that run and subtracting a 3 second bonus if the MicroMouse has not been touched yet. For example, assume a MicroMouse, after being on the maze for 4 minutes without being touched, starts a run which takes 20 seconds; the run will have a handicapped time of: 20 + (4*60 / 30) – 3 = 25 seconds. The run with the fastest handicapped time for each MicroMouse shall be the official time of that MicroMouse.
  2. As an alternative, at the discretion of the judges, scoring may be simplified as long as all contestants are notified at least 30 minutes in advance. For simplified scoring, each contesting MicroMouse is allocated a total of 10 minutes of access to the maze from the moment the contest administrator acknowledges the contestant(s) and grants access to the maze. Any time used to adjust a MicroMouse between runs is included in the 10 minutes. Each run (from the start cell to the center zone) in which a MicroMouse successfully reaches the destination square is given a run time. The minimum run time shall be the MicroMouse’s official time. A 3-second bonus will be subtracted from the time if the MicroMouse is not touched prior to that run.
  3. Each contesting MicroMouse shall be subject to a time limit of 10 minutes on the maze. Within this time limit, the MicroMouse may make up to 10 runs.
  4. When the MicroMouse reaches the maze center it may be manually lifted out and restarted or it may make its own way back to the start square. Manually lifting it out shall be considered touching the MicroMouse and will cause it to lose the 3 second bonus on all further runs.
  5. The time for each run shall be measured from the moment the MicroMouse leaves the start square until it enters the finish square. The total time on the maze shall be measured from the first time the MicroMouse leaves the start square (first activation).
  6. The time taken to negotiate the maze shall be measured either manually by the contest officials or by infrared sensors set at the start and destination. If infrared sensors are used, the start sensor shall be positioned at the boundary between the start square and the next unit square, and the destination sensor shall be placed at the entrance to the destination square. The infrared beam of each sensor shall be horizontal and positioned approximately 1 cm above the floor.
  7. The starting procedure of the MicroMouse shall not offer a choice of strategies to the handler.
  8. Once the maze configuration for the contest is disclosed, the operator shall not feed the MicroMouse with maze information.
  9. The illumination, temperature, and humidity of the room in which the maze is located shall be those of an ambient environment.
  10. If a MicroMouse appears to be malfunctioning, the handlers may ask the judges for permission to abandon the run and restart the MicroMouse at the beginning.
  11. If any part of a MicroMouse is replaced during its performance, such as batteries or EPROMs, or if any significant adjustment is made, the memory of the maze within the MicroMouse shall be erased before restarting. Slight adjustments, such as to the sensors, may be allowed at the discretion of the judges, but adjustment of speed or strategy controls is expressly forbidden without a memory erasure.
  12. No part of the MicroMouse (with the possible exception of batteries) shall be transferred to another MicroMouse. For example if one chassis is used with two different controllers, then they are the same MicroMouse and must perform within a single 10-minute allocation. The memory must be cleared with the change of controller.
  13. The contest officials shall reserve the right to stop a run, or disqualify a MicroMouse, if they believe its continued operation is endangering the condition of the maze. The judges also have the discretion to request a MicroMouse to retire early for lack of progress.

Credit for the content of this document goes, in whole or in part, to the following persons and organizations:

  • IEEE, the Institute of Electrical and Electronics Engineers, Inc.
  • APEC, The Applied Power Electronics Conference and Exposition

More Information

This is a traditional University level contest for electrical engineering\computer-science students all over the world. The goal is to acquaint the entrant to robotics and robot building principals.

Questions or comments about these rules should be directed to contests or the Seattle Robotics Yahoo Group.