On May, 24 2001, we had the exam of all the different microbots. After a conference by teacher Cristina Urdiales, each group started to prepare their robot, and to build a big maze for us to compete.

There was a big variety of robots in the exam: different ways to solve a maze, and alternative robots which seeked heat, solved puzzles or followed a small ball.

This is a picture of the five robots which competed for the labyrinth contest:

The Maze

This maze, made out of empty boxes, had a white background which allowed the black tape to contrast enough for the sensors to work properly. This boxes were there mainly to provide walls for the 'touching walls' robots, and a ultrasonic sensor-based robot.

This is how the maze ended:

If we number the upper picture's robots from left to right (being robot number 1 the one on the left), these were the results of the competition:

• robots 2 and 5: they both were the first to compete. No one of them used black tape, because they walked around the labyrinth by using contact sensors, some on the front and on both sides of the robot's structure. One of them couldn't get out of the maze.
• robot 4: equiped with ultrasonic sensors, which function was to detect a untrasonic emmiting source, placed on the exit. The reflected waves, though, drove this robot crazy, making impossible to find its way out.
• robot 3: this was a "left-hand-rule" robot, which turned left in every juction, but with some black line detection sensors placed quite far ahead, which allowed the robot to turn quite before reaching every bend. This robot got second place.
• robot 1: our robot, which first learned the labyrinth, and then went directly to the exit following the black line. And, as we had to use old batteries (we had a timing bug with a bend with the new batteries), things got very close: we finished only two seconds ahead robot 3, winning this competition!