Design of a Passively Balanced Spatial Linkage Haptic Interface

Abstract

This paper describes the design and implementation of a compact high fidelity desktop haptic interface that provides three-degree-of-freedom point-force interaction through a handheld pen-like stylus. The complete haptic device combines a spatial linkage, actuation, power amplification, and control electronics in a standalone package with a footprint similar to that of a notebook computer (33 cm×25 cm×10 cm). The spatial linkage is composed of one planar and two spherical subloops. Two versions of the spatial linkage were designed: a lightweight polycarbonate plastic version suitable for inexpensive mass production, and an aluminum and stainless steel linkage that offers greater reliability and higher stiffness. Both linkages were designed to be statically balanced over their full workspace.