Improvement of violinist robot using a passive damper device

The aim of this study was to determine how the violinist robot could produce a good quality of violin sounds. We began our study with the basic physics of producing sound with a violin. We found three parameters that influenced the quality of the sound produced by the violin; the bowing force, the bowing velocity and the sounding point. In particular, the bowing force was found to be the most important parameter in producing good sounds. Furthermore, to produce such sounds, a same amount of the bowing force must be applied on the contact point between a bow and a string. However, it is hard to keep a same amount of the bowing force on the contact point due to inherent characteristics of a bow. Thus, we primarily focused on the bowing force by considering bowing a string as a spring-mass system. Then, we devised a passive damper device to offset variables in the spring-mass system that may result in changing the bowing force on the contact point. We then validated our methodology with the violinist robot, a human-like torso robot.