Robot: Tune Yourself! Automatic Tuning for Musical Robotics

This paper presents a method for a self-tuning procedure for musical robots capable of continuous pitch-shifting. Such a technique is useful for robots consisting of many strings: the ability to self-tune allows for long-term installation without human intervention as well as on-the-fly tuning scheme changes. The presented method consists of comparing a detuned string's pitch at runtime to a pre-compiled table of string responses at varying tensions. The behavior of the current detuned string is interpolated from the two nearest pre-characterized neighbors, and the desired virtual fret positions are added to the interpolated model. This method allows for rapid tuning at runtime, requiring only a single string actuation to determine the pitch. After a detailed description of the self-tuning technique and implementation, the results will be evaluated on the new Swivel 2 robotic slide guitar. The paper concludes with a discussion of performance applications and ideas for subsequent work on self-tuning musical robotic systems.