1996 LEGO Workshop 1 Photos

Each picture here is a link to the original photo.

The Robots The Event The track The robots had to navigate the track in a figure 8, following the outer line. If they drifted off into a center square, they were disqualified. Two robots were placed on the track at a time, starting at opposite ends. Collision detection and handling were thus added to the problems of following the white line in the correct pattern. The equipment The robot's "brain" was a 68HC11 chip in a basic Rugwarrior-like board. The robot was powered by rechargable Nicad batteries. Inputs to the board were a serial cable with modular plug (from the computer) and a power input (to recharge the battery). The chip was programmed with Interactive C. The sensors The robot sensed the white line through a combination of IR emitters and detectors. In addition there was a larger IR detector for detecting the start signal. There was also a bump switch, which could be used for collision detection. Outputs from the board included some LEDs for diagnosis and a speaker. Navigating the track The robots had two LEGO motors each, which could be driven in forward or reverse independently. Information gathered by the sensors was processed to determine motor actions, thus producing appropriate behaviour. If a robot lost the white line, it might be able to pick it up again (but not always facing the right direction). Handling a junction The junctions posed two problems - detecting a fork in the line, and correctly deciding which fork to take. A robot which took the wrong fork was deemed disqualified. The robots were to do three laps of the track, which meant 6 junction decision points had to be passed correctly.