If you can dodge an infrared vision array, you can dodge a ball.

That was the motto of teams in the University of Colorado's Mechatronics class, who have been building autonomous, dodgeball-playing robots all semester.

The 11 teams capped off the spring semester on Monday afternoon with a robot dodgeball tournament inside the Integrated Teaching and Learning Laboratory on the Boulder campus. Two robots at a time were placed inside a small, robot-sized arena filled with bright orange Ping-Pong balls.

Once the students put the mechanical machines in the ring, the robots were on their own for four minutes. The bots made decisions based on student-designed programming -- no remote controls -- and tried to lob as many balls as possible at the other robot.

One robot named "Meg" after TV's "Family Guy" character suffered a brutal 17-7 defeat to "The Shredder." Meg got stuck and couldn't seem to get moving again, while her creators watched helplessly from the sidelines.

University of Colorado students watch as robots battle it out on Monday during a Mechatronics class, where students have been building autonomous,
University of Colorado students watch as robots battle it out on Monday during a Mechatronics class, where students have been building autonomous, dodgeball-playing robots all semester. (Mark Leffingwell)

"(The Shredder) is the best robot by far," said Eric Phaneuf, one of Meg's creators. "They have 10 vision sensors and we have one. We can't track them, so that was pretty much it."

Each robot was built with an infrared vision array, or sensors to detect either red or green lights on the other robot. Once the robot senses his foe, an onboard microprocessor controls motors, which theoretically move the robot toward its target.

That's how it's supposed to work anyway, Phaneuf said. With only one sensor, Meg's capabilities of finding The Shredder, approaching and lobbing a ball at it were limited, he said. The team even put a photograph of the real cartoon Meg on the robot as an "intimidation factor," said senior John Evanyo.

"We gave them a run for their money," said Gaurav Soin, another Meg creator.

ITLL co-director and the Mechatronics instructor Derek Reamon kept score of how many balls made contact with each robot from the sidelines. He's been teaching the class since 2002, and at the beginning of each semester, he warns students how time consuming building an autonomous robot from scratch can be.

Some students don't come back after that first lecture, he said, but the ones who hang around finish the semester with real-world experience to talk about in job interviews.

The robots require integrating mechanical systems and electrical systems, which is a valuable workplace skill, Reamon said.

"The people who hire our students, these skills are really directly applicable," he said. "(Some) can go work on Mars Rovers -- that's pretty much a more sophisticated version of the robots we're working on. It can also be medical devices that require some micro-controller inside. Really most any major industry would be pleased to have people that are proficient in systems integration."

The class brainstorms a semester-long goal at the beginning of the class. In the past, Reamon said students have decided to make their robots joust, race each other like in the video game "Mario Kart" and a find and diffuse a fictional bomb.

As the competition went on, faces crowded the floor-to-ceiling windows that looked in on the classroom. Spectators stood on chairs to get a better look at the action. One component of the demonstration is to show others how exciting science can be, Reamon said.

Patty and Ron Oelschlager drove from Colorado Springs to watch their son Max's robot. They brought with them bright orange flags, the same color as Max's bot, to cheer him on. Patty Oelschlager pointed to a plaque in the hall with the Confucius quote "I hear, I forget. I see, I remember. I do, I understand," and said she was glad her son got to practice the skills he learned in class at CU.

"It's hands-on, it's creative," Patty Oelschlager said. "This is the coolest thing that has happened."

Nearby, junior Teller Junak and his group made the finishing adjustments to their robot, Joe, complete with scorpion pincers and a tail.

Because he learned about "the guts" of robot Joe, Junak said he constantly contemplates the inner workings of everyday systems, like a garage door opener.

"This is why I joined mechanical engineering," Junak said. "Because I like figuring out how stuff works and building things, actually making physical things that do stuff and move around."

--Follow Sarah Kuta on Twitter: @SarahKuta.