Vanderbilt Register: Good vibrations coming out of Intelligent Robotics Laboratory

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Photo by Billy Kingsley

Electronic virtuoso: Engineering professor Kazuhiko Kawamura (left), director of the Intelligent Robotics Laboratory, observes as graduate student Kar-Wing Chan readies a humanoid robot (left foreground) to play a theremin, an electronic musical instrument that requires great precision to be played properly.

A theremin was used for the high tremolo notes played in the Beach Boys' big 1966 hit "Good Vibrations," according to Brian Wilson, the creative genius of the group. Led Zeppelin used the theremin in such songs as "Whole Lotta Love." The group also used it in their movie, "The Song Remains the Same."

The instrument has been used in such movie soundtracks as "Alice in Wonderland" as well as numerous science fiction motion picture scores to suggest the eerie and frightening.

The scientific principles used in the theremin are pretty simple, according to Jason Barile, who earned his master's degree in electrical and computer engineering at Vanderbilt last spring and who now works at the Microsoft headquarters in Redmond, Wash.

"You make a capacitor [electric circuit] with the antennas, and you become part of the circuit as you play it," Barile said. Barile did much of the original work involved with programming the robot to play the ther-emin. Kar-Wing Chan, a Ph.D. student in the lab, now works with the theremin.

In order to produce perfect musical notes, the robot plays "by ear" as opposed to memorizing the locations of notes relative to the antenna. Pitch detection software allows the robot to detect any error between a desired note and the note currently being played.

The robot's flexible arms facilitate the production of hu-man-like effects, such as vibrato and tremolo. The arms resemble actual human appendages with "muscles" that are pliant to the touch. "The arms are driven by pneumatically controlled actuators called rubbertuators that simulate the movement of human muscles," Kawamura said.

Additional software allows the robot to be controlled via a musical instrument digital interface (MIDI) device connected to an instrument, such as a synthesizer or guitar. Notes played through such devices are translated into commands for the robot, which quickly moves to play the note on the theremin.

Playing the theremin is diff-icult, according to Blair School of Music assistant professor Lawrence Borden. He explains that, unlike conventional instruments such as the piano, guitar or trombone, there is no physical reference between any note and its location relative to the instrument. The nonlinear response of the pitch antenna means that notes higher in pitch are located closer together spatially.

"That's one of the few instruments that a robot could play better than a human," Borden said.

Kawamura said Nashville's reputation as "Music City, USA" helped instigate the project. "The music industry is big here," he said. "We started brainstorming, and Jason thought of the ther-emin."

Barile says he has been obsessed with the theremin ever since he first saw one played in November 1993. In fact, he founded a theremin home page (http:///www.nashville.net/~theremin/). He showed video of the Vanderbilt robot playing the theremin at the First Interna-tional Theremin Festival in June 1997 in Portland, Maine. Barile said a documentary film, "Theremin: An Electronic Odys-sey," that aired in both England and the United States has been responsible for a huge comeback of interest in the instrument.

Equipment for the humanoid robot was supplied by Bridge-stone/Firestone, Inc. Kiyokazu Kurokawa of Japan also helped donate money for the theremin research.