Robot: Tune Yourself! Automatic Tuning for Musical Robotics

Murphy, Jim and Mathews, Paul and Kapur, Ajay and Carnegie, Dale

Proceedings of the International Conference on New Interfaces for Musical Expression

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.