The Waseda Flutist Robot WF-4RII in comparison with a professional flutist

In 2005, the newest version of the Waseda Flutist Robot, the Waseda Flutist Robot Number 4 Refined II (WF-4RII) was successfully implemented. The WF-4RII had improvements on the design of humanoid organs involved in flute playing such as robotic lips, lungs, arms, neck, tongue, oral cavity and vibrato system. The musical performance of the robot flutist is facilitated by a computer controller, a software sequencer and a vision system. An experimental setup was proposed to verify how well the WF-4RII could imitate a human performance. A statistical analysis using signal features of RMS, pitch, spectral centroid, spectral rolloff, number of crossings and sonogram was performed of the sound from the performances of a professional flutist and the robot to identify the main differences between them. Using a theme from Mozart's flute quartet KV 298, RMS feature of the robot and the flutist exhibit the same intensity. However, the dynamics of the robot were slightly different in some areas. Spectral centroids ofboth performances were similar, however, in some cases, the professional flutist presented a larger frequency distribution. Regarding the spectral rolloff, the robot's sound still lacks some high-frequency musical components during note transitions. In the zero-crossing feature, the professional flutist's sound presented more dynamic transitions. Regarding the sonogram feature, the professional flutist presents strong accents on the horizontal and vertical lines, whereas the robot presents strong horizontal lines but some distortion on the vertical lines.