Engineering News, November 28, 2005

November 28, 2005 Vol. 77, no. 13F

DRIVEN: EE 192's autonomous car project demands loads of time. At the height of it, EECS senior Quan Gan (right) says he put in 30 to 40 hours of lab time per week. He often arrived at the lab at noon and didn't leave until 2 a.m. Gan is pictured with his teammate, Charlie Chiau (B.S.'05 EECS) and their final car. (Photo provided by Quan Gan)

Along a track at NATCAR, applied lessons in electronic circuitry

The stats are stellar. For the fourth year in a row, Berkeley Engineering took first in the NATCAR competition held each spring at UC Davis. And, for the third year in a row, Berkeley placed in five of six top slots, effectively phasing out Davis, its toughest competitor.

In NATCAR, student teams develop small-scale electric cars that drive themselves efficiently (translation: no wandering, skidding) around a preset, wired path that curves, jogs horizontally, and loops back on itself. The fastest car wins. For Berkeley, that's meant developing cars of structural and computational brilliance.

The course behind it all is EE 192 "Mechatronics Design Lab," a capstone class taught by EECS professor Ron Fearing. "As an incoming freshman, I saw mechatronic cars at CalDay, and I thought, 'I want to make that in four years,'" says Quan Gan, an EECS senior with an ME minor, who took the class last spring.

On the first day of class, Gan set his sights on winning and teamed up with Charlie Chiau (B.S.'05 EECS). As the course website says, students start "with a 1/10th-scale radio-controlled car platform and a central processing unit/field-programmable gate-arrays board (already built), and designs sensors, electronics, and control algorithms..." Next step: deciding an optimal strategy. Professor Fearing advises all teams to build sturdy cars so that when they go haywire, careen off-course and slam into a wall (as they inevitably do), all's not lost. By the second test, though, Chiau and Gan's car hadn't gone much faster than earlier trials.

Time for drastic action, thought the pair. They built a new, lighter car in two days. "We put most of the weight in the back to make it turn faster and changed our aluminum bumper to a carbon fiber one," says Gan. The payoff: they gained three to four seconds.

On the day of the competition, the pair worked hard to tune their car to the new track and then clocked their best time at 35.34 seconds. But it wasn't good enough. Bryan Lin, James Liao, and Jerry Shen (all '05 EECS graduates) logged 34.62 and took the NATCAR win.

"Keep it simple," Lin advises. "We came in with all these ideas of how we could run the track faster than anyone else, but in the end, it came down to getting the basic functionality working as well as it could."

Gan agrees that simplicity is key. And despite not taking first place, he really enjoyed the course, he says. It helped shape his future plans: He's going to graduate school in ME.

Meanwhile, the pressure is on. This spring, EE 192 students go for a fifth consecutive win.

Do you have the drive? To learn more about the course, go to www-inst.eecs.berkeley.edu/~ee192/sp05/.

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