The University of Pennsylvania’s robotic soccer team continues its international reign, winning the Robot Soccer World Cup’s AdultSize Humanoid League for the second year in a row.

Its robot, THORwIn, a collaboration with UCLA, beat Iran’s Team Baset in a 5-4 shootout.

Coached by Daniel Lee, director of the School of Engineering and Applied Science’s GRASP Lab, the team consists of Steve McGill, Seung-Joon Yi, Heejin Jeong, Jinwook Huh, Marcell Missura, Dickens He, Sagar Poudel, Jianqiao Li, Yongbo Qian, Rachel Han, Kyuil Lee and Austin Small.

Penn is a mainstay at RoboCup, an annual event that brings the top engineering programs from around the world to face off against one another and push the limits of what humanoid robots can do.

This year’s event was held in Hefei, China, and featured hundreds of students from 175 teams, hailing from 47 countries.

RoboCup features several different kinds of robotic competitions, but its soccer leagues all have the same familiar rules: Get a ball past your opponents and into their goal. To simulate the human experience of the game, the robots must use eye-like cameras to see the ball, goals, and other players, and use brain-like onboard processors to put all of this information together.

Most important, the robots must make all decisions autonomously. Their human teammates spend months teaching them what the ball looks like, how to walk to it, and how to balance on one foot while kicking, but once the robots are on the pitch, they need to combine these skills on their own.

RoboCup’s ultimate vision is for its champion robotic players to hold their own against their flesh-and-blood counterparts. Penn’s division, the AdultSize Humanoid League, is closest yet to this lofty goal. At 4 feet tall, these robots are much more challenging to design and build than their “KidSize” counterparts; it’s a longer, heavier fall if one should tip over.

Owing to their size, weight, and expense, AdultSize league games are one-on-one. Teams take turns dribbling the ball past stationary objects and shooting against the opponent’s goalkeeper. THORwIn ultimately topped the field of six, besting teams from Japan, Iran, China, and Taiwan.

Beating a world-class team of human soccer players is many years away, but the skills necessary for each aspect of the game advances the abilities of humanoid robots and broadens the tasks they may one day be able to do. Simply identifying an object in a crowded environment, such as the ball, and walking to it while keeping balance is a major undertaking—but it would be an everyday requirement for a humanoid robot working in a home, factory, or hospital.

A similar philosophy motivates the DARPA Robotics Challenge. Another competition for humanoid robots, it features a gauntlet of various tasks that a robot might one day be called on to do in dangerous environments, such as cut through walls or walk over rubble. A version of THORwIn competed in the DRC Finals in June.