Near-Field Optical Reflective Sensing for Bow Tracking

This paper explores the potential of near-field optical reflective sensing for musical instrument gesture capture. Near-field optical sensors are inexpensive, portable and nonintrusive, and their high spatial and temporal resolution makes them ideal for tracking the finer motions of instrumental performance. The paper discusses general optical sensor performance with detailed investigations of three sensor models. An application is presented to violin bow position tracking using reflective sensors mounted on the stick. Bow tracking remains a difficult task, and many existing solutions are expensive, bulky, or offer limited temporal resolution. Initial results indicate that bow position and pressure can be derived from optical measurements of the hair-string distance, and that similar techniques may be used to measure bow tilt.