Physics and Astronomy

Robot - Clear That Trash
ObjectiveTo develop algorithms and programs to have a pre-built Lego Mindstorms robot clear an area of "trash".
PurposeTo encourage and demonstrate creativity, algorithmic thinking, simple programming, and teamwork.
ParticipantsTeams of up to six

Supplied by the Judges
A Lego Mindstorms kit provided to the participants. This will consist of a robot pre-built for the designated task and an infrared tower used to beam programs to the robot.

- A CD containing the Robotics Invention System software used to write programs for the robots. This will be provided to the participants as well.

- A computer used to program the robot. This will need to be a PC running Microsoft Windows, with USB support to connect to the infrared tower.

Additional Lego bricks and materials for building a simple arena (this can be as simple as large sheets of paper connected together with black magic markers used to mark off areas to be cleared of bricks by each competing robot). These materials will be assembled and provided on site by the time the participants arrive. A stop-watch is also required for time keeping purposes.

Supplied by the Teams


Teams of participants will be competing against one another, either with two teams at a time, or four teams at a time. Sheets of paper will be connected together to form an arena, which is then divided into two or four areas with black lines, depending on the number of competing robots. Each area must be of the same size. With two teams, the areas are side-by-side; with four teams, it is best to arrange the arena as a square divided into four smaller sub-squares. The judge will then distribute an equal number of Lego bricks across each team's area. The goal of each team is to program a robot that will clear its own area of Lego bricks. A light sensor is to be used to ensure that the robots stay within their own part of the arena. Note that it legal for a robot to clear its bricks either out of the arena, or into a neighbouring robot's area. Each team will be given the chance to test their robot before being placed into competition. The competition will consist of multiple rounds, each of a fixed length. The robot that either totally clears its area first, or has the fewest blocks left when time expires, wins the round. The number of rounds depends on the time available for the event.


Judging is based on the number of rounds won by each team. If there is a tie after the completion of the selected number of rounds, a tie-breaker is held to select the winner.





Mike Katchabaw, Department of Computer Science, The University of Western Ontario

Main Lego Mindstorms Web Site: http://mindstorms.lego.com/
More details on system requirements can be found at:

These and other similar events have been successfully held by the Outreach committee of the Department of Computer Science.. They can accommodate a wide range of age groups and experience among participants. Typically, a brief tutorial is required before each event to teach participants about the basics of programming the Lego robots. The programming environment is graphical, and much like building Lego in itself, where programs are built by connecting together blocks that carry out different actions. The tutorial usually takes between 10-15 minutes of time.

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