# Line Following

**Purpose:**

Build an autonomous robot that can follow a black line on a light coloured, flat surface.

**Levels of competition:**

There are two levels of competition: beginner and advanced. These designations are based on the level of difficulty of the line following maze.

** Beginner:** The course will be relatively simple (no right-angles) and short.

** Advanced:** The course will be relatively difficult (right-angles and tunnels) and long.

**Course:**

The course consists of a black line made of 3/4 inch wide black electrician’s tape on floor tiles (30.5 cm x 30.5 cm = 12″ x 12″).

Each floor tile will have one of the following line types: straight, curve (6″ radius), cross, light-angle turn or end-icon. The course is made by laying down floor tiles such that a continuous black line pattern is constructed.

**Robot:**

Dimensions: Less than 30 cm wide, less than 30 cm long, no height limit.

Mode of operation: Autonomous

Materials: Lego Mindstorms or built from scratch. Prebuilt kits are also ok.

**Rules:**

Contestant may place his/her robot at the start position him/her-self.

Contestant may start the robot him/her-self.

If the robot goes off the course:

A beginner contestant may place the robot on the line where it left the line.

For an advanced contestant this trial is finished.

Each contestant gets three trials. The best two are used to calculate a final score.

Each trial is timed.

**Score:**

The lowest score is the winner.

The floor tiles have the following point values:

Straight line = 1 point

Crossed lines = 2 points

Curved line = 3 points

Right-angle line = 5 points

End icon = 10 points

*Score = course total points – accumulated tile points*

where “course total points” is the sum of the points of the tiles that compose the course, and “accumulated tile points” is the sum of the points accumulated by the robot as it successfully negotiates the line across each tile.

** Example:** This is an advanced level example.

Suppose a course consists of 4 straight line tiles, 3 curved tiles, 1 crossed lines tile and the end icon tile. Therefore, the “course total points” is (4 x 1) + (3 x 3) + (1 x 2) + (1 x 10) = 25 points.

Suppose a robot successfully negotiates 2 straight line tiles, the crossed line tile and 1 curved line before going irreversibly off the course. Therefore, the robot score would be:

Score = 25 -[(2 x 1) + (1 x 2) + (1 x 3)] = 18 points.

Further, suppose that another robot does the same thing. The winner in this case is the robot that took the least time.