As part of the robotics course at the department of Computer Science, Utrecht University, students, in groups of three or four have to design, construct, and program a Lego MindStorms robot. The robot has to pick up soda-cans in a square arena and bring them to a particular corner of the arena as fast as possible. The goal of the project is that students will get an insight in the problems involving
Each group gets the following material:
No further material may be used.
The groups are expected to program their robot using NQC, the language developed by Dave Baum. Each group will get a copy of the most recent version of RCX Command Center, together with the NQC tutorial, to do the programming. (It is also allowed to use LegOS but at your own risk.) The robots should run in stand-alone mode. That means that program for the task must be downloaded to the robot (in program slot 1) after which the robot is started (using the remote control). there can be no interaction between the robot and a computer while performing the tasks.
The arena will be a square of approximately 2*2 meter surrounded by a brick wall. The bricks have size: l*w*h = 20*5*6.5 cm. There will be a double row of stones around the arena (so width = 10 cm). A number of obstacles will be placed in the arena, parallel to the walls. An obstacle consists of four bricks put together (so total size is 20*20*6.5 cm). Between obstacles and between obstacles and the wall there is at least 40 cm space. The floor is the standard floor in room C004. In one corner, a starting square area of approximately 50*50 cm is marked with a black line on the floor (about 2 cm wide). The robot starts in this area, positioned in the way the team likes. In the remaining area 5 white painted, empty soda-cans are placed, standing up. Cans can stand against walls or obstacles.
The robot has to find the cans and bring them to the starting area. Whenever he releases a can fully inside the starting area and the robot moves outside the area, the team can take the can out. When all cans are returned, the robot is finished. (There is a maximum time of 5 minutes for the robot.)
After this all cans are placed back at their original spot, and the robot gets a second chance to solve the problem, preferably using knowledge obtained in the first round.
The winner is the robot that brings all cans to the starting area in the shortest time. Here we take the minimum of the two times. If no robots brings back all cans, the one that brings back most cans wins (if multiple robots bring back the same number of cans, the winner is the one that takes the smallest total amount of time (counting only the time till the last can it returns)).
The following rules apply:
Although winning the challenge is, of course, nice, the project will be judged on other criteria. Each group has to hand in a document describing the global solution strategy chosen (with a motivation why this is the best strategy), the design of the robot (with a motivation of the design choices), and the programs (together with an explanation of how they work and how particular problems have been dealt with). Total length about 10 pages (you can also create a web page).
There will also be a price for the winning team.
Each team will get one Lego MindStorms set. The team is responsible for returning the complete set after the course is over, that is, on Dec 24 the latest. (It might be decided to leave one or more robots intact for demonstration purposes.) Initial batteries will be provided. The team is responsible for replacement batteries.
The team is expected to take care of the construction and programming at their own place. No room is provided for that. If this causes a problem, please contact the teacher as soon as possible.
One test session will be organized in which the teams can test whether their programs work in the actual arena. The test session will take place on Monday Dec 13, 13.00-15.00 hours in room C009.
The final competition will take place on Thursday Dec 23, 13.00-17.00 hours in room C004.
Each team must hand in their paper before the end of 1999 (by email to markov@cs.uu.nl).
For more information about Lego robots, see the Lego Robot Pages.