Seven-DOF Cable-Suspended Robot With Independent Metrology

Abstract

This paper presents a new cable-suspended robot. It is a 7-cable spatial design with a closed-form forward pose kinematics solution. Applications include automated machining, construction, and sculpting. This paper presents two new ideas. First, an independent, passive, six-string-pot-based Cartesian metrology system was built and tested since length measurements through the active drive system may be inaccurate for large-scale systems. Second, we introduce a new active cable tensioning approach wherein we control the displacement of a physical spring in-line with one of the active drive cables in attempt to ensure only positive cable tensions in all active cables. This is compared with an existing particular/homogeneous tensioning solution approach. Simulation examples are presented in this paper; we are currently building the proposed system for future evaluation work.