‘Counting on bad weather’

The second day of Carnival dawned unexpectedly sunny, and robot builders across campus cursed the beautiful weather, which threatened to derail the 13th annual Mobot races. “It’s so bright out — which is so not Pittsburgh,” said Leigh Ann Sudol, Ph.D. candidate in computer science, crouched on the sidewalk next to her robot, True, which was refusing to move. “This is the one event where we’re counting on bad weather.”

To win the Mobot races (Mobot is short for “mobile robot”), a robot must complete a 14-gate course in under four minutes. The course is a curvy white line, painted on the sidewalk outside of Wean Hall. “Most robots use video cameras, photoreceptors, or other sensors to detect the white line,” said Ben Brown, project scientist at the Robotics Institute and commentator. The reason bright sunlight can wreak havoc with the robots’ navigation systems is that it’s much easier to discern the line on a cloudy day than on a sunny day when dark, confusing shadows loom around every corner.

The race consists of two courses joined together, explained Catherine Copetas, assistant dean for industrial relations in SCS. First, the robots must pass through eight gates (like oversized croquet wickets) following a curvy painted path. Then, at the bottom of the hill, the path splits, and the robots have to pick the correct turns to pass through the last six gates (these are called “decision points”) before finally reaching the finish line. The robots must be completely autonomous — their creators can only watch from the sidelines.

Racing mobots is no easy task. No undergraduate team completed the course until 2002, said Dan Bothell, alumnus and research programmer, who has run his robot DJB in every race. The simplest way to complete the course is to build a robot that can see the white line painted on the concrete and thus travel through each gate, but they’re not required to follow the line, Bothell explained.

Past years have seen some memorable entries. Bothell’s favorite was the rat that someone had trained to follow the line. The race’s rules allow well-treated, non-primate animals. The rat, unfortunately, turned out to be more interested in the recently seeded grass at the edge of the sidewalk than the race, and mechanical entries once again reigned triumphant.

Robots can be entered in three categories — undergraduate, open, and exhibition. Entrants in the “open” category include graduate students, staff, and faculty. Those who just want to show off their robots, not run them, enter the “exhibition” class.

Out of this year’s eight entries, only four robots turned out to be functional. Ryan Sakauye showed the judges Clipboard, his not-quite-finished entry (it lacked a connection between the sensors and the motor). “I called it that because it’s made from a clipboard,” Sakauye explained. Maybe Clipboard will return next year, fully finished.

Two robots were stuck behind the starting gate, dubbed Gate 0. Next to the stranded True sat Pikachu alongside its creator, mechanical engineering alumnus John Palmisano. Pikachu won first place in the open category last year, but this year, the little robot wasn’t cooperating. Palmisano crouched over his laptop, frantically trying to fix the problem. When a bystander asked if this was the “new and improved” Pikachu, he answered, “Well... maybe not ‘improved.’ ”

As for True, the robot was roving, confused. “It’s found the line!” Sudol cried. “It’s found the line! It’s lost the line.”

Robotics Institute lab assistant Jason Winters’s entry, Ghostrider, a modified toy race car, was having trouble getting started as well. Winters decided to enter Ghostrider in the race only the day before, when he finally fixed the robot’s electrical problems. However, some problems remained: When Winters placed it on the starting line, Ghostrider zoomed off at high speed — straight into the registration table.

Bothell’s robot DJB, which has run in every mobot race, wasn’t feeling up to it this year. The paperback-sized vehicle made it to the second gate before stalling at a crack in the sidewalk.

Four robots left the rest in the dust: Plan B, FIWG, and Whisk in the undergraduate category, and Dodgy II in the open category. As the robots trundled down the twisty course, computer science professor Greg Armstrong cheered them on, donning a kilt and brandishing a broadsword.

Junior Daniel Dewey and sophomore Joey Gannon, both computer science students, walked alongside their creation, Plan B, as it skillfully navigated the course. Plan A, Dewey explained, had been a modified RC car with a video camera mounted on it, but they’d had to scrap it two weeks ago due to physical problems. Plan B steered by bouncing four beams of red light off the concrete and measuring the amount of reflection — the painted white line reflects much more light than the concrete. These beams of light were protected by a sunshade of cardboard and egg-crate packing foam, which made the robot look, as Dewey said, “kind of like a sheep.” The robot also featured an arm, ending in a “finger” borrowed from a virtual reality glove, which counted the gates the robot passed through.

Cornell Wright, a senior in ECE, explained that he and Justine Rembisz, a junior in mechanical engineering, had built their robot, FIWG, in nine hours the day before. The tiny, two-wheeled vehicle featured a pair of skis that helped the robot manage bumps and would have come in handy if the race had been snowed under. Wright and Rembisz were hesitant to explain what their robot’s name stood for but finally revealed the secret after Brown threatened to revoke any prize money until they did so. “It was a saying at our lab,” Wright said. “The last two words are ‘we’re going,’ the second word is ‘it’; you can figure out the rest.” Wright and Rembisz called FIWG their “blitz robot” since they had built it so quickly.

Somchaya Liemhetcharat, a senior in CS, said that he and Jonathan Wang, a junior in CS, had named their robot Whisk because it sounded fast. The vehicle is basically “a laptop on wheels,” Liemhetcharat said, with a webcam mounted on top. Thanks to some last-second changes to the Java algorithm running the robot, Whisk had no problem with the unexpected sunlight. At the end of each run, Liemhetcharat scooped up the robot, beaming like the proud father that he was.

The open class contender, Dodgy II, raced down the course on three wheels. Its top speed, creator James Bruce, Ph.D. student in CS, explained, was 10 meters per second, but the robot’s code couldn’t handle going quite that fast. Still, Dodgy II shot down the course at an impressive clip. The robot, which won first place in the open category in 2005, might be a future contender to beat the course record (1:01, set by Joshua Pieper, then-ECE master’s student in 2004).

In the end, Plan B was the only robot that managed to complete the course — although not speedily enough to count. But Plan B took home the first prize ($1000) anyway, managing 12 gates in 3:46. Dewey and Gannon won last year also, with a robot named Pajamas. Whisk came in second ($500), reaching gate 10 in 2:18. In third place ($250) was FIWG, reaching gate 7 in 3:41. James Bruce won first place in the open category ($250), his robot Dodgy II reaching gate 7 in one minute.

In previous years the competition also included MoboJoust, a separate contest where robots would fight to the death, based on the TV show BattleBots. But due to some reservations about hurting the poor little robots and the disturbing tendency of JoustBots to fly into the crowd, the Mobot committee decided to hold off on the jousting this year.

As fun as the 13th annual Mobot races were, Brown admitted the turnout of participants was “a little sparse.” He’s brainstorming ways to attract more contenders, including a race held in the fall, or a Mobots 101 course. Brown underscored that the race is a great way for students to showcase their talent to sponsors Lockheed Martin, Harris Corporation, and Morgan Stanley, as well as to faculty and fellow students. The Mobot committee hopes to get more students involved across campus, including engineering, computer science, and even design students.