Big Red conquers world robot 'soccer' finals in Stockholm

Sidney Leibovich, left, Cornell professor and director of the School of Aerospace Engineering, and College of Engineering Dean John Hopcroft, rear left, were among those greeting Raffaello D'Andrea, right, assistant professor of mechanical and aerospace engineering and coach of the robot soccer team, during the team's arrival Aug. 5 at Tompkins County Airport following its win last week at the world competition in Stockholm, Sweden. Robert Barker/University Photography

By Bill Steele

They didn't sing the old football song "See them plunging down to the goal," but the Cornell Big Red team became champions of world robot "soccer" last week when they beat a highly regarded German team 15-0 in the finals in Stockholm, Sweden.

The event, called the Robot World Cup Initiative, familiarly known as RoboCup, pits teams of tiny but incredibly smart robots against each other. In the final, Cornell's team -- the first the university has fielded in the 3-year-old competition -- played the FU-Fighters from the Free University of Berlin in a match carried live on Swedish television and streamed live on the World Wide Web. One observer called the Cornell victory "a drubbing."

The Big Red was competing in the "small" league, in which robots are about 6 inches in diameter and the playing field is the size of a regulation table-tennis surface.

RoboCup was created to foster research in robotics and artificial intelligence (AI). A team consists of five robots, communicating with their "mother" computer and with each other by radio. A video camera surveying the playing field tells the central computer where the players and the ball -- a golf ball -- are. Individual robots also can have on-board sensors. Once programmed, the robotic system is completely on its own, with no remote control by human operators.

The Cornell system uses two computers, one to process information from the video camera and another to decide on strategy based on the video information. The Cornell robots are about 7 inches tall and weigh about 2 kilograms. They are driven by a 17-watt motor powered by a 9-volt battery and can reach a speed of 2 meters per second in 0.7 seconds.

Unlike many robots in the competition, they have a solenoid-driven "kicker" mechanism that can be used in special situations, in addition to bumping the ball. The goalie is a slightly different design, capable of moving rapidly from side to side. The robots have on-board infrared sensors that tell them when the ball is near; in competition, the central computer tells a robot when it is in position to kick, and the robot kicks when it senses the presence of the ball.

The Big Red's road to the finals began July 29 with an opening game against a team fielded by the South Korean high-tech firm Robotis, winners of the South Korean championship and heavy favorites in RoboCup.

For the Cornell team even to be ready to play was a triumph of engineering resourcefulness because several pieces of luggage, including key pieces of equipment, had been lost by the airline. The team arrived in Stockholm Monday night, July 26, and Tuesday and Wednesday were spent in frantic phone calls to obtain technical specifications for the missing equipment and searches throughout Stockholm to buy replacement parts.

On Wednesday night Raffaello D'Andrea, the Cornell assistant professor of mechanical and aerospace engineering who coaches the team, e-mailed: "We now have 12 hours before our first game ... and we have not tested the system, let alone many individual components. It's going to be another long night ..."

In the first game, against Robotis, the Big Red was down 1-0 early in the first half. The students suspected something was wrong with the system until it was noticed that a chair near the field cast a shadow that was interfering with the robot goalie's vision. After the chair was removed, Cornell's defense was impenetrable, and the game ended 2-1 for Cornell.

Continuing in the early round-robin play, Cornell defeated Portugal 8-0 and New Zealand 33-0, advancing to the quarterfinals. On Monday, Aug. 2, Cornell routed a team from Temasek Engineering School in Singapore 20-1 to advance to the semifinals.

The semifinal game Aug. 3 with another Singapore team from Ngee Ann Polytechnic was a barnburner. Cornell took the lead early in the first half but received three warnings and a yellow card for aggressive collisions with the other team's robots. This was inevitable, D'Andrea said, because Cornell's robots are more powerful.

Cornell brought on a substitute for the player receiving a yellow card, to prevent a red card and mandatory expulsion. By the half the score was 2-2.

For the second half, the Cornell team decided to reduce the speed of its players, both to avoid further penalties and to give more control in passing. From there on Cornell advanced steadily, and the game ended Cornell 6, Singapore 2.

The Big Red team went into the final unsure, because the FU-Fighters had robots with a very powerful kicking mechanism. But within the first 10 seconds of the game, D'Andrea said, he knew Cornell had the upper hand.

"Our robots are faster, more maneuverable, can navigate around obstacles, can pass the ball, shoot on net accurately and essentially beat their robots to every free ball," he said.

Within one minute, Cornell scored its first goal. From there on, he said, it was "just a matter of seeing if we could get a shutout." The German team got only one shot at the Cornell goal, blocked by the goalie so effectively it surprised even the Cornell engineers.

Cornell's RoboCup team was made up of participants in a class conceived and taught by D'Andrea. In preparation for the competition, the class was divided into two competing teams, known as Team Brazil and Team Italy. In a match played on the Ithaca campus in May, Team Brazil defeated Team Italy 4-0. The best features of both team's designs were incorporated into the final robots, and the entire class worked on the final version.

One reason the Big Red has been so successful, according to Bart Selman, associate professor of computer science and one of two faculty advisers to the team, is that the team is made up of a mix of graduate and undergraduate computer science, mechanical engineering and electrical engineering students. Norman Tien, assistant professor of electrical engineering, is the other faculty adviser.

Four students traveled to Stockholm for the competition: undergraduate Aris Samad-Yahaya and graduate students Lars Cremean, Andrew Hoffman and Tom Karpati. Jin-Woo Lee, visiting lecturer in mechanical and aerospace engineering and project co-instructor, also accompanied the team.

Team Brazil was composed of Dennis Huang, Salman Qureshi, Mike Smullens, Thomas Karpati, Jason Oversmith, Alexander Lau, Alex Sepulveda, William Hegarty, Syaril Hussin, Charles Poon, Aris Samad-Yahaya, Christopher Lau and Aaron Delfausse. Team Italy was David Hsu, Yooki Park, Scott Aaronson, Thibet Rungrotkitiyot, Ryan Hansen, Ray Chang, Harry Cuadrado, Lars Cremean, Ted Hwang, Livingston Cheng, Andrew Hoffman, Lance Hazer, Emily Winston and Stephen Chang-Chi Kao.

D'Andrea's play-by-play account of the competition can be read at http://www.news.cornell.edu/releases/Aug99/robojournal.html. The Cornell RoboCup team's site is http://www.mae.cornell.edu/Robocup/intro.html.