Paper Reading #6: Shimon: an interactive improvisational robotic marimba player

Comments
Cindy Skach
Evan Schuchardt


Reference Information
Title: Shimon: an interactive improvisational robotic marimba player
Authors: Guy Hoffman, Georgia Institute of Technology, Atlanta, GA, USA
              Gil Weinberg, Georgia Institute of Technology, Atlanta, GA, USA
Presentation Venue: CHI 2010: 28th ACM Conference on Human Factors in Computing Systems;
Date: April 10-15, 2010;
Location: Atlanta, GA, USA

Summary

This paper presents Shimon, the robotic marimba player. Shimon is an autonomous robot designed to create interactions with human players.  The robot's features encompass music perception, interaction, and improvisation with the capacity to produce melodic and harmonic acoustic responses through choreographic gestures. The two main frameworks used are an anticipatory action system, and a gesture-behavior system.

The authors explain that many computer-based music systems have been implemented, but mainly focus on electronic reproduction and amplification of sound through speakers, which does not capture the richness of acoustic sound. Using an HCI approach, the authors have focused on Shimon's perceptual and interactive aspects such as listening, improvisation, and interaction.  This is an attempt to merge the mechanical aspect of a robotic musical instrument, and an anthropomorphic aspect of musical robots.  This creates a new platform for research in the Robotic Musicianship application.

When designing Shimon, the authors explain that they wanted large movements for visibility, as well as fast movement. for virtuosity. Another consideration, was a wide range of sequential and simultaneous combinations. The result, as the authors put, was a "combination of fast, long-range, linear actuators, and two sets of rapid parallel solenoids, split over both registers of the instrument."

Shimon has four arms actuated by a voice-coil linear actuator at its base, and running along a shared-rail. Shimon also has a socially expressive head that is non-humanoid. It serves the purpose of conveying emotional state and liveliness.

Improvisation is achieved through three modules:

• Call-and-Response: this module allows the system to respond to a musical phrase with a chord sequence. The challenge is to be able to respond in time and play on a synchronized beat. This module makes use of the anticipatory structure of gestures.
• Oppurtunistic Overlay Improvisation
• Rythmic Phrase-Matching Improvisation

The authors have been able to implement an expressive robot with the help of the head. The expressive robotic head bobs to signal the robot's internal beat. The head will also turn towards a player or towards the marimba to signal that it is about to play, or signal the player that he/she should play next.

Shimon's head also can make a blinking effect through its shutter, and a slow breathing-like behavior to convey a continuous "liveliness".

Discussion

This was one of my favourite papers to read. It seems that the authors have covered much of the questions I had and know exactly what they want to achieve. Though there are not a lot of statistics, we can still appreciatte the work once we watch a video of the robot on youtube.