In This Soccer Match, Players Are Robotic But That's the Goal
During a national championship last year, a University of Pennsylvania soccer team was on the verge of a big upset. In the final game against Carnegie Mellon University, a group of players had battled to a 1-1 tie when disaster struck. A Pennsylvania forward booted the ball toward his own net by mistake. David Cohen, a trainer for the team, watched in horror as the orange ball rolled past the goalie, for Carnegie Mellon's second and clinching goal.
The culprit: a small electronic dog, one of the four Pennsylvania teammates competing in RoboCup, a soccer tournament for robots that's becoming a cult hit on college campuses.
The loss "was heartbreaking," says Mr. Cohen, 22 years old, an engineering student at Penn. "But it was also kind of hilarious."
Sony Corp.'s battery-operated Aibo dogs are the stars of the RoboCup soccer championship.
Blending artificial intelligence, robotics and soccer, RoboCup is an obscure competition known mostly to computer-science wonks at top universities around the world. Unlike the supercomputers that regularly confound chess grandmasters, soccer robots are still quite crude. The players, mainly battery-operated dogs called Aibos, tend to wander out of bounds for no reason. They have trouble seeing the ball. Because battery life is short, they sometimes crumple to the ground in the middle of a match as if taking a nap.
Other RoboCup teams use human-like robots that stand on two feet. Those can barely move and often fall over after kicking a ball. There are also smaller robots that zip around on wheels. They look more like tricked-out toasters than world-class athletes.
Nevertheless, RoboCup, which is shorthand for Robot Soccer World Cup, has an eye-popping long-term goal. By 2050, it wants to create a humanoid robotic soccer team that can defeat the winner of soccer's real World Cup. This grand ambition "is a beautiful allegory" for the field of robotics, says Dean Kamen, creator of the Segway scooter: "Make a device that's functionally equivalent and indistinguishable" from a human being.
In June, more than 100 teams will square off in Bremen, Germany, for the 10th-annual RoboCup World Championship. The competition will coincide with the human World Cup, which is being held in Germany at the same time.
The idea to use soccer as a way to experiment with robots appeared in a 1993 paper called "On Seeing Robots," by Alan Mackworth, professor of computer science at the University of British Columbia in Vancouver. Mr. Mackworth thought soccer was a more intriguing challenge than chess because robots would need to see and interact with each other. He suggested soccer over other sports because it didn't necessarily require complex physical movements such as throwing.
The concept got a boost in the U.S. a year later when Peter Stone, then a computer-science postgraduate, saw Mr. Mackworth demonstrate soccer-playing toy cars at a conference on artificial intelligence.
"I got excited," recalls Mr. Stone, who now heads the RoboCup program at the University of Texas at Austin. Mr. Stone, who has played semiprofessional soccer in the U.S., decided to make robotic soccer the topic of his Ph.D. thesis. At about the same time, scientists in Japan launched the first robotic soccer initiative, calling it RoboCup.
Since then, RoboCup has caught on with teams from nations as diverse as Germany and Iran. Eight separate robot categories include "small-size" and "four-legged." The tournament has also helped inspire other advances in artificial-intelligence research. For example, a related competition uses search-and-rescue robots that emergency personnel are testing in disaster situations like earthquakes.
Jim Moorhouse, a spokesman for the U.S. Soccer Federation, says "It all sounds like 'The Terminator,' " referring to the 1984 sci-fi movie about time-traveling, killer robots starring Arnold Schwarzenegger. Alexi Lalas, a member of the 1994 U.S. World Cup squad, says RoboCup's organizers underestimate the real sport's complexity. Mr. Lalas cites famous players such as England's Alan Shearer and Gary Lineker whose instinct in front of a goal, he says, is innate, not learned.
"There are tactics that go into soccer, but there's also a creativity about the game" that will be tough to duplicate with computer code, says Mr. Lalas, who is now president of the New York Red Bulls soccer team.
Today's robots are vast improvements over previous models. First-generation RoboCup participants were similar to remote-control cars. In a 1997 tournament in Nagoya, Japan, pitch-black smoke started billowing from a robot in the middle of a match, participants recall. Those early models, which sometimes caught on fire, "looked sort of like little time bombs," Mr. Stone says.
That changed with Sony Corp.'s 1999 introduction of the Aibo, a robotic "pet" dog. (Pronounced EYE-bow, it means "companion" in Japanese.) Japanese teams had already been using the Aibo during its test phase, and others soon realized the benefits of enlisting the robots as soccer players.
"Imagine a laptop with legs and a camera, that's what the Aibo is," says Manuela Veloso, a professor of computer science at Carnegie Mellon. Her university's team dominates RoboCup in the U.S., with Texas, Pennsylvania and the Georgia Institute of Technology making fast progress.
Armed with video cameras, infrared sensors and wireless Ethernet cards, Aibos process 30 pictures a second to create a virtual topography of their surroundings. The playing fields, roughly 12 feet by 18 feet, are surrounded by color-coded beacons that help orient the robots.
A computer chip stored in the Aibos tells the players what to do. For example, a complex series of algorithms calculates where a player should go -- and where it should kick the ball -- based on its position on the field and the location of its teammates. Goals are also color-coded to let the robots know where to shoot, though Aibos occasionally get confused.
At his RoboSoccer Lab in Austin, Mr. Stone, 34, is preparing for the fourth-annual U.S. championship, which is set to take place in late April in Atlanta. The professor is currently overhauling the software that runs his team, Austin Villa, named after Aston Villa of the English Premier League. He's working on last-minute, make-or-break adjustments -- tweaking robots' vision, for example, to account for variations in tournament lighting and flooring. So far, progress has been choppy.
In a recent demo, one Aibo spun in place like a dog chasing its own tail. "We're racing against the clock," Mr. Stone said, as an Aibo waddled crookedly toward an orange ball on a green field.
The Aibo teams have an even bigger challenge ahead of them. In January, Sony pulled the plug on the Aibo Entertainment Robot line. The robots, which cost about $2,000, weren't profitable. That means no more new Aibos and no more dog-robot teams.
机器人──足球新星
去年举办的全美锦标赛对宾夕法尼亚大学(University of Pennsylvania)足球队来说真是一场惨痛的经历。在对卡内基梅隆大学(Carnegie Mellon University)的决赛中，两队踢成了1比1平，这时倒霉的事突然降临了：宾夕法尼亚大学的一个前锋不小心把球踢进了自家球门。该队的教练戴维?科恩(David Cohen)一脸惊骇，眼睁睁地看著橘黄色的足球越过守门员直入球门，为卡内基梅隆大学足球队奠定胜局。
罪魁祸首是一只小小的电子狗，它是宾夕法尼亚大学参赛的四名队员之一。那场锦标赛名叫RoboCup，是专门为机器人举办的足球锦标赛，如今这种比赛在大学校园里非常流行。
那次失败“真令人伤心啊”，现年22岁的科恩说。他是宾夕法尼亚大学工程系的学生。“不过也够滑稽的。”
结合了人工智能、机器人工程学和足球的RoboCup对于大多数人来说是一项籍籍无名的赛事，只有全球一流大学里那些计算机专业的书生们才熟知。与那些常常挫败象棋大师的超级计算机相比，足球机器人显得相当原始。参赛的机器人大多是被称为Aibo的由电池启动的机器狗，它们时不时会莫名其妙地跑到界外，而且有时找不到球在哪里。由于电池寿命有限，机器狗有时会在比赛途中倒在场地上，好像要打个盹似的。
参加RoboCup的其他球队则起用两脚直立的类人机器人。这种机器人几乎不能移动，常常踢了一球后就跌到在地了。还有一种小型机器人，依靠轮子四处移动。它们看上去更像是包装精美的烤面包机，而非世界级的运动员。
尽管如此，RoboCup（全称是Robot Soccer World Cup）拥有让人瞠目的远大目标。该赛事计划到2050年建立起一支能打败“世界杯”足球赛冠军队的具有人类特点的机器人足球队。这一宏伟目标“是机器人工程学领域一个美丽的寓言”，赛格威电动滑板车的发明者迪安?卡曼(Dean Kamen)说。“（人们的目标是）设计出一种功能上和外形上能与人类相媲美的产品。”
今年6月份，百余支球队将云集德国的不莱梅，参加第十届RoboCup世界锦标赛，该赛事每年举办一次。本届比赛正巧与世界杯足球赛的时间一致，而且后者的比赛地点也在德国。
利用足球来发展机器人是1993年由艾伦?麦克沃思(Alan Mackdworth)在他的一篇题为《机器人之我见》(On Seeing Robots)的论文中首先提出来的。麦克沃思是温哥华不列颠哥伦比亚大学(University of British Columbia)的计算机教授。麦克沃思认为，与像棋相比，足球更富有挑战性，因为机器人在足球比赛中必须相互认知和交流。他指出，选择足球，而非其他运动是因为足球无须复杂的身体运动，如投掷等。
一年后，机器人踢足球的概念在美国得到了发扬。当时，计算机专业的研究生彼得?斯通(Peter Stone)在一次关于人工智能的会议上看到了麦克沃思演示踢足球的玩具汽车。
“我当时很兴奋，”斯通回忆说。他目前在德克萨斯州大学奥斯汀分校(University of Texas at Austin)负责RoboCup项目。斯通曾参加过全美半职业性足球赛，他决定把机器人足球作为自己的博士论文题目。几乎与此同时，日本科学家也推出了首个足球机器人研究项目，也叫RoboCup。
从此之后，RoboCup就在德国和伊朗等国流行起来。目前该赛事已设有8个小项，其中包括“小型机器人比赛”和“四条腿机器人比赛”。这一锦标赛同时促进了人工智能研究领域的相关发展。例如，搜救机器人领域的发展如火如荼，救援人员现正在地震等灾难性环境中对这种机器人进行测试。
美国足球协会(U.S. Soccer Federation)的发言人吉姆?莫尔赫斯(Jim Moorhouse)说，“这听上去就像电影《终结者》(The Terminator)一样。”《终结者》是1984年拍摄的科幻影片，由著名影星阿诺德?施瓦辛格(Arnold Schwarzenegger)主演，主题是时空之旅和机器人杀手，。曾参加1994年世界杯足球赛的亚历克斯?拉拉斯(Alexi Lalas)说，RoboCup的组织者低估了这项运动的复杂性。他指出，像英国的阿兰?希勒(Alan Shearer)和加里?莱因克尔(Gary Lineker)等足球明星临门一脚的悟性是天生的，而非后天学到的。
“足球里包含技巧策略，但还蕴涵著创造力”，这是难以用电脑程序模仿的，拉拉斯说。他目前担任纽约红牛队(Red Bull)的队长。
今天的机器人已经有了显著的进步。参加RoboCup的第一代机器人球员类似于遥控小汽车。人们至今还记得，在1997年于日本名古屋举行的一场比赛中，滚滚黑烟从一个机器人身上冒出。那些早期的机器人有时会著火，“看上去有点像定时炸弹，”斯通说。
随著索尼公司(Sony Corp)在1999年推出“宠物”机器狗Aibo，情况发生了变化。当时日本队早已对Aibo进行了比赛测试，其他队也很快意识到了将机器人作为足球队员的好处。
“设想一个长了腿和摄像机的笔记本电脑是什么样，那就是Aibo，”卡内基梅隆大学的计算机教授曼勒?维罗索(Manuela Veloso)说。卡内基梅隆大学的RoboCup研究水平在美国首屈一指，而德克萨斯州大学以及乔治亚理工学院(Georgia Institute of Technology)进步飞快。
配备了摄像机、红外线传感器和无线网卡的Aibo每秒种内能处理30张图片，从而对周围的状况了如指掌。足球比赛的场地大约长18英尺、宽12英尺，球场四周围著彩色的信号灯，以帮助机器人辨认方向。
Aibo身上携带的电脑芯片能发出踢球指令。例如，根据机器人在场上的位置以及同伴的位置，它能进行一系列的计算，告诉球员应该朝哪儿走、在哪儿踢球等等。球门也是彩色的，以便让机器人知道朝哪里射球，尽管Aibo有时候依然会搞不清楚。
在德克萨斯州大学奥斯汀分校的RoboSoccer实验室里，现年34岁的斯通正在为第四届全美机器人足球锦标赛做准备，此次比赛将于4月下旬在亚特兰大举行。这位教授正在修改控制该校球队奥斯汀维拉(Austin Villa)的电脑软件， 球队的名字源于英格兰超级联赛的球队阿斯顿维拉(Aston Villa)。他所做的是最后的、决定成败的调整──修改机器人的视线范围，以便适应不同比赛的灯光和场地等。到目前为止，这项工作的进展时断时续。
在最近的一次演示中，Aibo原地旋转起来，就像狗在追逐自己的尾巴。“我们正在与时间赛跑，”斯通指著绿色球场上一个笨拙地奔向橘黄色足球的Aibo说。
这支Aibo球队还面临著更大的挑战。今年1月份，索尼公司停止了Aibo Entertainment Robot生产线的运作，原因是这些造价约2,000美元的机器人不赚钱。这就意味著今后不会再推出新的Aibo了，也没有机器狗足球队了。
