A Forward Kinematic Code for Cable-Driven Parallel Robots Considering Cable Sagging and Pulleys

The large workspace of cable-driven parallel robots is one of their key benefits. Experiments have shown that in practice the reachable workspace is often smaller than the theoretically predicted one. To improve the workspace computation, a new forward kinematic code, which considers the previously neglected effects of cable sagging and pulleys, is introduced. For an exemplary robot with eight cables, the new forward kinematic predicts a 18.5% smaller workspace and a 27.8% lower platform stiffness than the standard geometric model. The findings of this work show the importance of considering the effects of cable sagging and pulleys in the workspace computation and kinematic codes, especially for large cable-driven parallel robots.