High Fidelity Multi Finger Haptic Display

Abstract

The fingertip haptic display (FHD) is a five bar mechanism developed at the University of Washington for haptic interaction with the fingertip of the operator. The two-degree-of-freedom mechanism was computer optimized to accommodate the workspace of the human finger inflexion/extension with a high degree of kinematic isotropy. Direct drive with frictionless flat-coil actuators ensures low torque ripple, inertia, and static friction in the actuation system for high fidelity haptic rendering. This paper describes a redesign of the position sensing arrangement, I/O hardware and software as well as thermal modelling to improve performance and stack four devices for use with index, middle, ring and little finger in a multifinger haptic display. Some results of the initial performance evaluation are given. Promising applications are expected to include palpation training for medical personnel, museum displays enabling the visitor to "touch" art, as well as psychophysics research: exploring the limits of human touch perception.