Development of the anthropomorphic saxophonist robot WAS-1: Mechanical design of the simulated organs and implementation of air pressure feedback control

The research on the Waseda Flutist Robot, since 1990, is an approach to understand human motor control from an engineering point of view, as well as introducing novel ways of musical teaching. More recently, the authors have proposed as a long-term goal the aim to enable musical performance robots to interact with musical partners. For this purpose, we present two research approaches: implementing more advanced cognitive capabilities on the Waseda Flutist Robot no. 4 Refined IV (WF-4RIV) (i.e., visual/aural processing) and developing a new musical performance robot (i.e., duet performance). In this paper, we have focused our research on developing an anthropomorphic saxophonist robot as a benchmark to better understand how the interaction with musical partners can be facilitated. As a result, we have developed the Waseda Saxophonist Robot no. 1 (WAS-1) with 15 d.o.f. that mechanically simulates the organs involved during saxophone playing. In this paper, we present the details of the mechanical design of the simulated organs, as well as the implementation of the musical performance control system based on air pressure feedback control. A set of experiments was proposed to verify the effectiveness of the designed simulated organs to produce the saxophone sound and to verify the effectiveness of the proposed air pressure feedback control by comparing the saxophone performance of WAS-1 against an intermediate saxophonist. Finally, a preliminary experiment was carried out to analyze the feasibility of realizing a duet performance with the WF-4RIV. From the experimental results, we have confirmed that WAS-1 is capable of producing a saxophone sound nearly similar in terms of pitch and volume to the performance of a human player.