MOBOT Open House provides hints for competition

Each day, students walk over the white line in front of Wean Hall without noticing it. While this winding line may seem insignificant and is overlooked for most of the year, it becomes extremely important each year, around Carnival time, for participants in MOBOT.

MOBOT, which stands for "MObile roBOT," is held each year on the 212-foot course in front of Wean Hall. The competition offers generous prize money, with $1,000 going to the first-place winner.

A MOBOT open house was held on February 21 to provide students with information about the competition. Several presenters offered helpful hints for getting started on building a robot to navigate the course. "You can put together a MOBOT in a week's time," said Arne Suppé, the MOBOT winner of 1997.

Sebastian Scherer, a first-year in computer science and 2001 winner of the Open Class competition provided a detailed overview of the major components of a MOBOT. Scherer explained the different possibilities for powering the robot: one wheel with one motor, two wheels with one motor, or two wheels with two motors.

Scherer recommended the last option, with a motor on each wheel to allow for easier steering. Using this method, one motor can be run faster than the other to cause the robot to turn in one direction.

In order to measure how fast the robot is moving, encoders can be used to keep track of the motor speed or axle rotation. Scherer explained that it is important to be able to measure the speed of the robot because it is generally a good idea to slow it down when going down the hills on the course.

One of the most critical functions in a MOBOT is the system used to detect the white line. Light sensors can be used to measure the intensity of light reflected from the line. Scherer suggested that it is helpful to put a light source, such as LEDs, on the bottom of the robot so that in low light conditions the line will still reflect light. This is also useful considering that last year's MOBOT competition was run during the rain - which makes light conditions poor and unpredictable.

Scherer also pointed out that the robot's control system needs to be able to detect cracks and bumps in the pavement so that it continues moving rather than getting stuck.

While building a MOBOT may appear to be a daunting task, there are many resources available for assistance. The official MOBOT web site (www.cs.cmu.edu/~mobot) provides competition rules, and even a MOBOT starter kit, which is available for purchase.