t's hot in here.It's one of the first really warm days of

spring, a Monday afternoon in mid-May,and several hundred people are crammedinto Upson Hall lounge. Asthough the stand-ing-room-only crowd didn't make the placestuffy enough, 1,000 watts of lighting hasturned it into a steam bath-and open win-

dows are strictly forbidden. To top it off, it's the begin-ning of the last week of classes, and exams and papersare stacking up likeplanes over O'Hare. But still the spectatorsare jammed in together 10-deep, and they seem contentto stay all afternoon.

After all, it isn't every day you get to watch robotsplay soccer.

In the middle of the room sits a humble tabletop, agreen-and-white rectangle topped by a metal frame; thebright lights and camera equipment suspended above givethe contraption the look of a doll-sized movie studio. Butthis is truth, not fiction. In the next half-hour, 10 robotswith names like Scoot, Sleepy, and Major Tom will be putthrough their paces in agility trials, control demonstra-tions, even an exhibition drag race. Then comes the mainevent: a real-time soccer match starring 10 autonomousrobots, built from scratch by Cornell engineers.The officialname for this competition-at once Lilliputian

and hugely ambitious-is the Robot World Cup Initia-tive, but everyone just calls it the RoboCup. For the pasteight months, two dozen students have been workinglike mad, and it all comes down to 10 minutes of play todecide which of the two teams gets to go to Stockholmfor the international tournament. And there, it will beCornell versus the world.The Big Red's first-ever RoboCup entry is the brain-

child of a man who knows a whole lot about systemsengineering-and a whole lot about soccer, for that mat-ter. RaffaelloD'Andrea, an assistant professor ofmechanicaland aerospace engineering (MAE), started the RoboCupprogram last fall. His aim: to give students a taste of

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Building a team of sotaste of real-world e~

t:cer-playing robots gives students agineering experience. By Beth Saulnier

PHOTOGRAPHS: LEFT, FRANK OIMEO! UP; RIGHT. NICOLA KOUNTOUPES! UP

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what they'll encounter in the realworld,from deadlines and cost limi-tations to old-fashioned teamwork. "Stu-dents find that more and more, as theygo into industry, they aren't just workingon one thing. It's not just widgets any-more. It's big, complex systems,"D' Andrea says. "I wanted to teach aclass where they could work inmultidisciplinary teams. In industrytoday, that's the norm."

W ith those goals inmind, D'Andreaconvened thetraditional engi-neering think

tank: the student pizza party. After anight of brainstorming last spring, hesettled on the idea of a robotic soccergame-and found out that it alreadyexisted, having been first played inNagoya, Japan, in 1997. He decidedCornell should throw its virtual hat intothe ring, and promptly got 60 applica-tions for the 24 openings. "It's a realproject," D'Andrea says of the coursesappeal. "We're actually building some-thing." A year later, D'Andrea and hisRoboCup proteges are, quite literally,in the hot seat. "After eight months,Saturday night was the first time thingsworked the way they were supposed to,so we've spent the last 24 hours justfine-tuning," he says as the studentssweat and scramble to finish setting upfor the big game. "These guys have beenworking around the clock."

The students have had access to theUpson lounge for the past 28 hours. Inthat time, they've had to move every-thing down from the RoboCup lab onthe floor above, rebuild the playing field(whose overhead grid required somejuggling with the room's ceiling tiles),and make sure everything is still run-ning right. But that's not as easy as itsounds. Both teams-one dubbed Italy,the other Brazil-rely on an overheadcamera, the eye-in-the-sky of the so-

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called" global vision system" that tellsthe computers where the players areon the field. But that system has neverbeen tried outside the lab, and the Upsonlounge has windows. Big ones. Andthough Ithaca can usually be countedon for some comforting gloom, todayit's blazingly sunny. "We've never testedit in here during the day," D'Andreasays as students climb onto chairs totape dark material over the doors andwindows. "Lighting is very critical. Weneed a constant source of light on thefield, and it has to be uniform."

D' Andrea is standing between onesign that says NO FLASHPHOTOGRA-PHY and another forbidding cellularphones. They aren't kidding. At a typicallive stage performance, flashes are adistraction; here, they can be a disas-ter. "It'll make the robots spin uncon-trollably," D'Andrea says with a grinthat says he's seen it all before. As forcell phones? They can interfere withthe wireless communication betweenplayer and computer, which, as he putsit, "may send the robots on a self-de-struct course."

Along one wall, students are bentover keyboards and gazing into moni-tors. Even just a few minutes before thegame, others are taking the "hats" offrobotic competitors and giving theirinnards a final check. "I haven't reallyslept since Wednesday," says ScottAaronson, a glassy-eyed computer sci-ence major from the Philadelphia area."I think a lot of people here could saythe same."

The RoboCup course, a year long,is open to all engineering and computerscience students. The number of cred-its earned-eight-hardly reflects thetime commitment involved. D'Andreaonce calculated that each team put in8,000 hours of work, for a total of abouteight person-years. Assuming an annualsalary of $60,000 plus benefits, theRoboCup would add up to a $1 mil-lion industrial project. "It's been fun-

a lot of work, but fun," saysTeam Brazil'sAlex Sepulveda, an M.Eng. candidatein mechanical engineering from RioPiedras, Puerto Rico. "Sometimes thingsjust kind of go nuts, but most of thetime they work. I liked seeing other peopledoing what they do. It's more realis-tic, not just focusing on your own thing."

Of the 24 students in Cornell'sRoboCup, 60 percent are M.Eng. can-didates (the class satisfies the projectrequirement for those in the new sys-tems engineering option). In choosingwhom to admit, D'Andrea aimed for amix of disciplines to reflect a real in-dustrial team. Thus, 40 percent of thestudents are mechanical engineers, 40percent electrical, and the rest fromcomputer science and operations researchand industrial engineering. And evenafter eight months of technical wran-gling, that interaction among fields hasmade the biggest impression on the team-mates. "It's been a really educationalexperience for me," says Aaronson, whoworked on artificial intelligence for TeamItaly. "Some of the biggest challengeshave been communication-humancommunication. We're doing CS, butwe can't operate in a vacuum. We needto know what's going on mechanicallyas well." Or, as Brazil team leader andM.Eng. student Dennis Huang '98 putsit: "The mechanical engineers and thedouble-Es have to talk to each other."

It's getting close to game time now,and Huang admits he and his teammatesare feeling rushed. "We're not as readyas we'd like to be. But we're going towin, because our robots are well-built.They can dish out and take almost any-thing." But Huang's Team Italy coun-terpart-David Hsu, an M.Eng. studentin systems engineering from San Mateo,California-jokes that his team will winfor one simple reason: "We're betterengineers." While Team Brazil concen-trated on their robots and software, Italypinned its hopes on complex electri-cal and mechanical systems, including

two different designs for the goalieand the field players. "We'veworked with a really aggressiveschedule and a really aggressivedesign," Hsu says, "and we pulledit off in the end."

If the RoboCup is the mostcomplex project an undergrador M.Eng. student is likely toencounter (unlike Cornell's, mostteams are made up of doctoralcandidates), the rules are rela-tively simple. Each team has fiverobots, including one goalie, whoface off for possession of a brightorange golf ball on a soccer pitchconsisting of a regulation Ping-Pong table. The robots must oc-cupya floor area no greater than180 square centimeters, and beless than 15 centimeters tall. The goalsare SOcentimeters wide-about a thirdof the length of the short end of thefield-and are painted either bright yellowor blue. The games consist of two 10-minute halves, with a break in between.

To enter the third-annual RoboCupcompetition, Cornell had to submit a paperand video for approval; it was D'Andrea'sidea to give the Big Red project a com-petitive flavor by forming two internalteams and letting them play for the rightto go to Europe. But to ensure the strengthof the Cornell squad as a whole, he cre-ated a canny list of student goals, in de-scending order. To wit:

1. Cornell wins RoboCup 1999.2. Cornell wins RoboCup 2000 and

beyond.3. A student's own team wins the

Cornell tournament.Goal Number One puts the focus

on the university as a whole rather thanon the individual team, which inspiredBrazil and Italy to collaborate on theglobal vision system. Practicing that vitalkindergarten virtue-sharing-allowedboth teams to develop the best possiblesystem and devote more time and moneyto other parts of the project, like ro-

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botics and artificial intelligence. GoalNumber Two encourages good docu-mentation (since most of the presentplayers will have graduated), as well asextra research into high-risk, high-payoffconcepts that may not be used this yearbut could give Cornell a future edge.Goal Number Three-the question ofwhether Brazil or Italy will representthe university at Stockholm-comes ina not-so-distant third. "This was by far

the most exciting class I've ever taken,"says Team Italy member Lars Cremean,a senior in mechanical engineering fromWolcott, NewYork. "It's a pretty dauntingtask to get robots to do anything au-tonomously. I got a real sense of howto go about designing a system fromthe ground up."

The RoboCup was founded in 1997,a banner year for robotics and artifi-cial intelligence. In May, IBM's Deep

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Blue beat world chess champion GaryKasparov; on Independence Day, NASAdeployed the first autonomous roboticlander, Sojourner, as part of its MarsPathfinder mission. The idea of roboticsoccer had been first mentioned in 1992by Alan Mackworth, a professor at theUniversity of British Columbia; mean-while, similar discussions were goingon in japan. The first RoboCup was an-nounced in 1995 and played two yearslater in Nagoya, with more than 40 teamscompeting before 5,000 spectators. Itgrew to nearly 100 teams the follow-ing year, and more are expected inStockholm.

But RoboCup organizers don't plan

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to settle for watch-ing miniature ro-bots play soccer.The ultimate goalis to have a teamof fully autono-mous humanoidrobots capable ofbeating humanplayers-and notjust any humans,but the mostrecen t winnersof the WorldCup. Target date:sometime in themid-21st century."This goal maysound overly am-bitious given state-

of-the-art technology today," says theorganization's official web site, <www.robocup.org>. "Nevertheless, we believeit is important that such a long-rangegoal be claimed and pursued. It onlytook 50 years from the Wright broth-ers' first aircraft to the Apollo mission. . . [and] from the invention of thedigital computer to Deep Blue." It's aheady prospect-and, incidentally, oneD'Andrea doubts will ever be realized."It will be a long, long time, if ever,before machines can match what a humanbeing can do athletically," he says.

At this year's tournament, all eyeswill be on Carnegie Mellon University,which has taken home the title two yearsrunning. "They have by far the best ar-tificial intelligence," D'Andrea says ofthe top-seeded squad. "Our strength isour integrated approach-and our ro-bots are by far the best." The RoboCupis a round-robin tournament with quar-ters, semis, and a final. Before each match,a coin toss decides which team gets toput up its global-vision camera first.Player substitutions are allowed-teamscan bring an unlimited number ofspares-and a human referee overseesthe action, which has been known to

include robots spinning uncontrolla-bly and parts flying every which way.The ref blows the whistle, D'Andrea says,"if the robots get out of hand."

The professor gave his team a com-petitive edge by videotaping last year'sRoboCup final in Paris, so Cornell stu-dents could seewhat they'd be up against.Further proof of his mettle: when Frenchmuggers attacked him with pepper sprayand stole his briefcase, he managed tohold onto his camera with one hand-and use the other hand to whack themwith his laptop. SaysBrazil team memberArisSamad-Yahaya: "Professor D'Andrea'spretty intense."

D' Andrea was born near Venice ofparents who had little formal educa-tion, but adventurous spirits and a yenfor travel. After the death of his father,his mother moved to Toronto with hertwo sons in tow and all of $500 in herpurse. (There's just the faintest traceof an Italian accent in D'Andrea's voice,along with a healthy dose of Canadianin his outs and abouts.) The futureRoboCup mentor earned an undergradu-ate degree in engineering physics fromthe University of Toronto (where hemet his wife, Leanna), followed by aPh.D. in electrical engineering from CalTech. He came to Cornell in january1997 and now focuses his research onthe field of feedback control.

D' Andrea fell in love with socceras a toddler and kept playing-for anengineers team in college, a club at CalTech, a co-ed squad at Cornell calledThe Rovers. At the RoboCup game inUpson, a spectator (Mike Coleman, Ph.D.'98, an MAE lecturer and fellow soccerfanatic) asks him if knowing a lot aboutthe game gives a RoboCup team an ad-vantage. "Truthfully, no," D'Andrea grinsback at him. "But. I think if you playsports, you have a competitive nature."

Cornell's RoboCup system is com-posed of three elements: robots, globalcontrol, and computer vision. (Likemostteams, the Big Red squad opted for an

overhead camera, which tracks the col-ored Ping-Pong balls mounted atop therobots, but participants are also free todesign a "local" system, with camerason each robot.) If the robots are the playersand the vision system their senses, thenglobal control is the coach-the mindthat puts all the game factors togetherand formulates a strategy using data fedto the camera 60 times per second. Thegoalie, for example, constantly runs anoptimization program to see how closethe ball is, and whether to move accord-ingly. "The key point is that it's fullyautonomous," D'Andrea says. "There'sno human interaction."

But there's been plenty of humaninteraction over the past eight months,as the team members assigned to fivedifferent aspects of the project-electri-cal and mechanical engineering, artifi-cial intelligence, vision, and R&D-workedtogether. As the students building therobots set to their task, programmersdeveloped a simulation (complete withcollisions, friction, delays, and noise) thatwould allow them to test the software,which included 10,000 lines of code forthe AI system alone. The actual robotscame into play only in the final month.

Meanwhile, each team designed itsown circuit boards and sent them outfor manufacture, then installed and testedthe components. D'Andrea's role wasmore coach than team owner; for in-stance, although he advised Team Italyagainst a complex electronic design, theywent ahead with it anyway. "The stu-dents have a lot of pride, and they'revery creative," he says. "They were ableto do it, but man did they work hard."Mechanically, the two teams also tookdifferent approaches. For example, Brazildecided to make its robotic wheels outof mousepad material (friction beinga vital factor in the robots' ability tostop, turn, and kick) while Italy optedfor hobby wheels; Brazil's kicking mecha-nism used a wind-up spring, while Italy'sused electromagnets.

The robots are protected by a layerof foam padding, which may seem su-perfluous for what's not supposed tobe a contact sport-until you see themin action. Each robot weighs in at 1. 7kilograms, and they move like light-ning, with a maximum velocity of 2.5meters per second, or 9 kilometers (5.6miles) per hour. "These guys are powerhogs," D'Andrea says ofthe robots, whichrun on a 9.6-volt nickel cadmium bat-tery. "We'd really like to find batteriesthat will power them for the durationof the game." The rules allow" accidental"contact-the players aren't supposedto turn their soccer match into a hockeybrawl-but defense can turn into of-fense faster than you can say Pele. "Defi-nitely a big part of the game is puttingyourself in front of another robot,"D' Andrea says. Or, as he put it in hisintroduction to the Brazil vs. Italy match:"I'm 100 percent sure you're going tosee collisions."

He was right. Just over a minuteinto the 10-minute game (D'Andrea haddecided they'd only play one half), Brazilscored-and Italy's goalie seemed to takeit hard. "Whoa! Whoa!" somebody yelled."The goalie's going crazy!" He spun outof control, bashing into side walls andother robots, and by the time Team Italygot him under control, he had to betaken off the field. Without a backup,all the Italy squad could do was sit aspare field robot in the goal with itspower switched off, and Brazil rackedup two more goals in quick succession.

The score was 3-0. Then, out of asense of fair play, Brazil decided to shutoff its goalie aswell-and promptly scoredagain. Final tally: Brazil 4, Italy O. Still,there were no hard feelings. "I thoughtthe play was pretty impressive," saysCremean. "It went so much smootherthan I've ever seen it go." He chalksup the goalie's problem to human er-ror-a soldering mistake that caused ashort between the robot's two boards-and adds that Italy's system made great

strides in the project's home stretch."A few weeks ago, the obstacle avoid-ance algorithm was pretty primitive,"he says. "Negotiating the walls was abig thing. The robots just ran into themand tried to keep going."

Aaronson, one of two juniors onthe RoboCup squad, plans to come backfor more in the fall. "This year, we haven'thad the opportunity to do a lot of higher-level AI," he says. "But very simple thingstook a lot of math and a lot of twid-dling to get to work. When you startinteracting with the robot and you re-alize how difficult it is to get them todo simple things, a lot of your dreamsabout what's feasible start to change."

A fterthe match, D'Andreahosted a barbecue,where the RoboCupplayers came to an un-expected decision: the

Brazil and Italy systems will be inte-grated, and the best of both sent toStockholm. The class has been more aboutcollaboration than competition, the stu-dents say-further proof that they'vebeen following D'Andrea's number-onegoal all along. "The win was great andall, but it wasn't the win that made usfeel really good," says Samad-Yahaya,a senior electrical engineer from Ma-laysia. "It was seeing the system work-the feeling that we managed to get itall running pretty well."

For Samad-Yahaya, the RoboCupturned out to be a life-changer. His ex-perience doing original research on tra-jectory generation for Brazil's AI teamconvinced him to pursue a Ph.D., whichhe will begin in the fall of 2000 aftertaking ayear off. "It was a real eye-openerto me," he says. "It was really excitingto figure out a new way of doing things,to discover new science. We created some-thing truly remarkable." ;!

Beth Saulnier is associate editor ofCornell Magazine.

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