Line Follower

UK Micromouse Line Follower Rules

A. Competition Classes

  1. From June 2024, the line follower competition has a single class formerly called “Half Size Line Follower”.

  2. The linear dimensions are nominal values and organisers will seek to implement these nominal dimensions, actual dimensions may vary slightly due to fabrication tolerances. The width of the white lines may vary by up to +/- 2mm.

B. Rules for the Line Follower Competition

  1. Line Followers must be self-contained, and not externally operated by wire or by any other form of remote control during the race.

  2. Except for the battery pack, the handler shall not make any addition, removal, replacement or change to the hardware of a Line Follower during a contest. It is however permissible to make minor repairs.

  3. A Line Follower shall not exceed 125mm in overall length, 125mm in overall width and 250mm in overall height.

C. The Line Follower racetrack

  1. The track is laid out using a white 10mm line on a black base. Tracks may consist of small tiles, large boards or it may be printed on a vinyl sheet. Refer to Fig. 1 for a small example track layout.
    (Download as PDF)
    2. fig 1: Sample line follower course

  2. The racetrack shall comprise of straight lines and circular arcs.

  3. The radius of any arc shall normally be no less than 75mm (+/-5mm), measured from the centre of the line. The length of the arc shall be no less than 75mm.

  4. The length of a straight shall not exceed 6000mm.

  5. Crossovers are permitted, but will be at right-angles only. Line Followers shall not turn left or right at a crossover.

  6. The starting line and the finishing line are to be located in a straight section of the circuit. The finishing line is to be located between 250mm and 500mm behind the starting line.

  7. A starting marker and finishing marker are to be affixed at the starting line and the finishing line on the right side of the track pointing in the direction of the race. The area between the starting and finishing line shall be called the start-finish area (fig 2).

    Fig 2: Start/Finish Area

  8. The track shall be straight for 75mm either side of the start-finish area, and either side of a crossover.

  9. A marker shall be affixed on the left side of the track in the direction of the race at each point where the curvature of the track changes.

  10. Turn and start markers shall be the same width as the line and placed 25mm from the centre of the line. The markers will be 20mm long and have their centres aligned with the change in curvature. See Fig. 3 for details of the main dimensional constraints.

    fig 3: Marker Dimensions and Positioning

  11. A track may have arcs with different curvatures linked continuously.

  12. The surface of the racetrack shall normally be level, however:

    1. Portions of the track may be inclined at a maximum of 5 degrees.

    2. Differences in level of up to 2mm may exist at the joints between modules.

    3. Gaps of up to 2mm may exist at the joints between modules.

    4. Complaints about the grip on the track surface will not be entertained.

    5. The course will be substantially flat and free from obstruction and markings for a minimum of 65mm from the centre of the line.

D. Timing of laps

  1. The time it takes for a Line Follower to make the circuit of a track shall be the recorded lap time.

  2. To determine the lap time of the Line Follower, the period from the time the sensor at the starting line detects part of the Line Follower body to the time the sensor at the finishing line detects part of the body of the same Line Follower shall be clocked.

  3. The Line Follower shall have a specified maximum number of attempts to run the track within a single time period of stipulated length (typically 3 to 5 minutes and from 3 to 4 attempts to be decided by the organiser on the day of the race). If the performance time limit is reached and the Line Follower is in the midst of a run, the Line Follower will be allowed to complete the run and the lap time will be valid if the run is successful.

  4. Within the given performance time, the handler is allowed to replace batteries and/or alter program parameters to the Line Follower.

  5. Line Followers shall start anywhere within the defined start-finish area, and shall go in the specified direction. After crossing the finishing line, the Line Follower must automatically come to a complete stop, and remain stationary for at least two seconds, failing which a penalty time may be added to the score.

  6. If a Line Follower leaves the white line, and has not crossed the finishing line, it will be considered to have gone off the track, and that run shall be invalid. A line follower will be judged to have left the line if, at any time between the start and end markers there is no part of the robot vertically above some part of the line.

  7. The organisers will ensure that the track is located within a typical indoor environment in so far as is feasible. No request to adjust the lighting shall be entertained.

  8. The organisers may demand from handlers such explanation concerning their Line Followers as is deemed necessary, and they may use their discretion to direct handlers to withdraw their entry, disqualify them, and take any other necessary measures.

  9. Once a run has begun, the handler may not touch the robot until the run is complete or the robot needs to be recovered. Touching the robot at any time during a run will cause that run to be disqualified and no time will be recorded.

E. Organisers’ Decision

  1. The organisers reserve the right to make changes to any of the above in the interest of fair play and sportsmanship, and to ensure that all competitors have an enjoyable competition.

  2. In the event of ambiguity, the organisers’ interpretation of any clauses of the rules shall prevail.