A 2-D Infrared Instrumentation for Close-Range Finger Position Sensing

Haptic interfaces are proposed for enhancing human-computer interfaces through the rendering of interaction forces. Among them, encounter-type haptic displays feature an original way to provide the user with an improved transparency: their end effectors remotely track the fingers of the operator and encounter them only when force rendering is required. These interfaces call for the development of specific position tracking systems. In this paper, a 2-D hollow instrumentation for remote and marker-free close-range finger tracking is proposed. It encloses 16 infrared proximity sensors. Its design specifications are based on a literature review of finger motion and a simulation of the tracking dynamics. Some calibration methods, organized as a function of their complexity level, are also described. The instrumentation performances are experimentally evaluated to assess its adequacy with the targeted application. This design accounts for the demonstration that infrared proximity sensing is a viable solution for close-range sensing of targets as changing as human body parts.