Last Friday, with unusually warm and sunny weather, the University’s 10th annual Mobot competition was held in front of Wean Hall. Using the painted lines running across the sidewalk, autonomous mobile robots built by members of the Carnegie Mellon community raced through croquet-like gates, vying for the most accuracy and speed.

Although many Mobots quickly ran off the course into the grass, three placed at this year’s competition in the undergraduate category, each of their engineers winning a cash prize. To qualify for placement in the prize-winning rankings, Mobots must pass through at least two of the 18-square-inch gates along the designated path, excluding the starting gate. Two other awards and checks were given, one in the Open Category, which is for non-undergraduate CMU students, and the other for the Judge’s Choice Mobot.

“The most important thing about Mobot is to make a very simple design that works,” advised Sebastian Scherer, who built the first-place-winning Mad Kuh Mobot, which went through all of the gates but was just a shade outside of the maximum time limit. In the end, Scherer’s Mobot’s official winning run was through thirteen of the fourteen gates in 3:51.28 minutes. Scherer also won first place last year in the undergraduate category and was able to improve on the number of gates passed through this year by two.

A senior in computer science, Scherer has participated in the Mobot races for the past four years. In that time, he’s learned a lot about how to create a winning Mobot. The infrared light sensors that guided Mad Kuh along the bright white lines of the course were covered by material used in dark rooms to contain light to make sure that the sensors didn’t detect excess sunlight. Scherer also said that he “idiot-proofed” his Mobot with beeping alarms so that on race day, even if he was nervous, everything would be properly plugged in.

Rattle & Hum, designed and built by mechanical engineering senior John Bellinger, came in second with eleven gates in 3:46.72 minutes. Named for its noisy stepper motor, Rattle & Hum was particularly unusual for having five wheels instead of four. Like Scherer’s Mobot, it also used infrared light sensors to distinguish the lines from the unpainted sidewalk pavement. However, instead of a dark room filter, Bellinger used cardboard from a Froot Loops box to cover his Mobot’s sensors, making his Mobot the most colorful in the winner’s circle. Bellinger also won the Decision-Point Challenge in the Mobot Mini-Challenge, which took place a week and a half before the actual race by completing gates 9 through 14 in 39.69 seconds.

Third place went to mechanical engineering senior John Palmisano with his Mobot, Pikachu. During the race, the actual Mobot was hidden from view: due to an intermittent program bug that hindered light detection, Palmisano had to completely encase his Mobot beneath cardboard, computer paper, and duct tape to allow the light detectors to work properly.

Another interesting feature of Palmisano’s Mobot was its quad-steering. Each wheel drove independently of the others, allowing for a quick and complete range of motion. Palmisano also said that he didn’t actually build Pikachu for the Mobot races; for his personal satisfaction, his Mobot was designed after the first robot that he ever built.

The crowd out beside the races was particularly wowed by graduate electrical and computer engineering student Josh Pieper’s Rio Mobot, the winner of the Open Category. Though he completed the entire course in a record-breaking 1:01.43 minutes, Pieper says that his record is likely breakable and hopes that someone will improve on his source code, which is available online at http://4north.no-ip.com:8080/mobot.

Using a first generation Compaq iPaq and laptop camera, Pieper’s Mobot navigated the course with incredible speed and accuracy because the program running it was designed to “know” where the gates were located as soon as the robot hit a certain decision point, which are the circular parts of the race path where the Mobot has to choose which route correctly takes it to the finish line. To test his Mobot before the race without spending hours in inclement weather, Pieper designed a computer program that simulated both the real course and what the Mobot would “see” at the actual course.

The Judge’s Choice award went to Zia Sobhani, a visiting engineer from the Massachusetts Institute of Technology. Although her Mobot, Hero, was too large to pass through any of the gates on the course, judges were thoroughly impressed with her remodeled Hero-1 robot. The Heathkit Hero-1 was first released in 1982 as one of the first robots with a degree of artificial intelligence and ability to interact with its environment. Sobhani obtained her Hero-1 last summer and worked on reconstructing the previously broken and unusable robot with Pieper. The night before the Mobot race, Sobhani came down to Pittsburgh from Boston and built the necessary parts to allow Hero to follow the Mobot race lines and pick up the wickets, knowing that there was no way that the Hero would actually fit through the gates.

Next October will mark the 25th anniversary of the creation of the Robotics Institute at Carnegie Mellon, and staff members hope that this competition’s winning Mobots will be temporarily donated to the school to be put on display as part of the celebrations.

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