X-ACTA: eXtended Analytic Center Tension distribution Algorithm for fixed and mobile cable-driven-parallel-robot
For researchers and engineers working on CDPRs, this method enables safe and smooth operation beyond the WFW, which is critical for aggressive maneuvers or cable failure scenarios.
This paper introduces X-ACTA, an extended Analytic Center method for selecting cable tensions in Cable-Driven Parallel Robots (CDPRs) outside the Wrench-Feasible Workspace (WFW). The method maintains continuous and differentiable tension profiles, ensures fast real-time convergence, and reduces wrench errors to a negligible area, outperforming the state-of-the-art in smoothness and wrench error as confirmed by Pareto dominance.
Steering Cable-Driven Parallel Robots (CDPRs) beyond their Wrench-Feasible Workspace (WFW) augments their capabilities in challenging scenarios such as during aggressive maneuvers or following a cable failure. In this context, although the determination of cable tensions is a well-studied topic, only a few approaches address these scenarios. Therefore, this paper introduces an extended version of the Analytic Center method as a criterion for selecting cable tensions outside the WFW while maintaining differentiability and including non-linear constraints. Notably, the proposed method maintains continuous and differentiable tension profiles, ensures fast real-time convergence to a unique solution, and, in contrast to other slack-based formulations, relegates wrench errors to a negligible area of the WFW. Its superiority in terms of smoothness and wrench error is confirmed via Pareto dominance with respect to the leading state-of-the-art method. Lastly, the effectiveness of the method is demonstrated through numerical experiments.