Knightmare Is the King of 6.270By Michael A. Saginaw
After enduring one preliminary round and eight grueling rounds of competition, a robot named Knightmare emerged as the undefeated winner of the 1993 LEGO Robot Design contest (6.270) Tuesday night.
Sumit Basu '95 and Loren C. Shih '95, the masterminds behind Knightmare, designed and built the robot, which defeated the robots of 54 other teams in head-to-head competition. Tuesday's contest was the first in the class's seven-year history that freshmen did not win.
In each 60-second Robo-Knights match, two autonomous robots started on opposite ends of a table. They rolled around the table, trying to move foam blocks to their end zone, which comprised the last six inches of each end of the table. Several matches made up each round, and a robot defeated twice was eliminated from the competition.
A robot earned points by moving blocks into its end zone, and it earned more points if it could stack blocks on top of one another. A robot could also earn points by dragging blocks from the opponent's side of the table back to its end zone, but this was difficult because a moat two inches deep divided the playing field in the middle. However, 30 seconds into the match, a drawbridge was lowered across the moat and the robots could easily move from one side of the table to the other.
Knightmare stayed on its side of the table for the entire 60 seconds. It rolled toward a block on the table, stopped, and unfolded two parallel arms on either side of the block. The arms squeezed together, gripping the block lightly.
The robot lifted the arms high into the air and positioned the block carefully over a receptacle. The arms spread apart and the block fell into the receptacle. Knightmare methodically moved on to the next block, lifted it, and dropped it on top of the previous one, earning a lot of points by stacking the blocks on top of one another. After picking up the blocks, the robot rolled to the end zone and stayed there for the rest of the match.
One of the distinguishing features of Knightmare was its consistency. "We worked 14 hours a day, every day," Basu said. "We tested [the robot] hundreds of times."
"The most important thing is how reliable your robot is. We spent hours hunting for errors," Shih said. Shih and Basu were awarded a plaque for their efforts.
Contest began in 1987
Michael B. Parker started 6.270 in 1987 as a Course VI analogue of Introduction to Design (2.70), a mechanical engineering class. The course is run entirely by students. This year, the contest was organized by Matthew L. Domsch '94, Pankaj Oberoi G, Karsten P. Ulland '94, Sanjay S. Vakil '94, and Anne Wright.
The robots' bodies were made of LEGOs. Each robot was required to broadcast its location continuously by emitting infrared radiation, and teams could put sensors on their robots to pinpoint the opposing robot.
In addition, dissimilar polarized lights positioned behind each end zone shined toward the center of the table. These enabled the robots to determine their orientation on the table.
The floor of each end zone was magnetically encoded, making it possible for robots to identify when they were in the end zone. The area of the table near the moat was black, so that robots could detect whether they were near the moat.
The design contest was sponsored and funded primarily by the Department of Electrical Engineering and Computer Science. Several companies also lent support. Microsoft Corp. helped fund the contest and provided each participant with a contest T-shirt. The company also provided late-night pizza and Chinese food.
Motorola Semiconductor Inc. donated the microprocessors and all other integrated circuits used by the robots. Polaroid Inc. donated the motors which propelled the robots, and Gates Energy Products Inc. donated the lead-acid batteries which powered them. A piece of cardboard cut from one of the boxes used to transport these parts during construction served as a thank-you card to the sponsors. Everyone who made a robot signed the card.
Between the rounds of competition Tuesday night, the people who organized and sponsored 6.270 demonstrated special robots they had made. One robot could sense variations in color, and it was programmed to roll towards bright green foam blocks. Green blocks were tossed on to the table, and the robot rolled right to them. "Company Tank" was a robot with thick tread on its wheels. It was designed to cross the moat before the drawbridge was lowered, but experienced considerable difficulty.
One robot had a video camera on it. The image picked up by the camera was broadcast on a large screen in 26-100, so that the audience could see the 6.270 playing field from the robot's point of view.
Elementary school girls competed
One robot named "Yoshi" was built by members of the girls science club of Williams Elementary School in Auburndale, Mass. The one adult on their team, Walter R. Bender SM '80, is a principal research scientist at the Media Laboratory.
"I had them think about what a robot is," he said. The youths put the robot together and figured out how it should move in order to transport blocks into the end zone. "They spent a long time figuring out the positioning of the robot," Bender said.
The girls told him what commands they wanted to give the robot, and he programmed those commands into its memory. "Yoshi" won one match against "The Return of the Loss-Bot," a robot built by a team of MIT students.
After the competition, Basu and Shih were interviewed on camera. The interview will become part of a Motorola program slated to be shown at a convention of engineering professors to encourage other schools to have contests like 6.270.