Actuation space reduction to facilitate insightful shape matching in a novel reconfigurable tendon driven continuum manipulator

TL;DR

This paper introduces a simplified, sequential shape-matching control strategy for reconfigurable tendon-driven continuum manipulators by reducing actuation space through curvature and torsion analysis.

Contribution

It presents a model-free actuation framework that leverages shape projection into curvature-torsion space to facilitate insightful and efficient shape matching.

Findings

Pattern analysis in curvature-torsion space reveals influential tendons.

Sequential actuation improves shape approximation and end-effector positioning.

Model-free control bypasses complex reconfigurable manipulator modeling.

Abstract

In tendon driven continuum manipulators (TDCMs), reconfiguring the tendon routing enables tailored spatial deformation of the backbone. This work presents a design in which tendons can be rerouted either prior to or after actuation by actively rotating the individual spacer disks. Each disk rotation thus adds a degree of freedom to the actuation space, complicating the mapping from a desired backbone curve to the corresponding actuator inputs. However, when the backbone shape is projected into an intermediate space defined by curvature and torsion (C-T), patterns emerge that highlight which disks are most influential in achieving a global shape. This insight enables a simplified, sequential shape-matching strategy: first, the proximal and intermediate disks are rotated to approximate the global shape; then, the distal disks are adjusted to fine-tune the end-effector position with minimal impact on the overall shape. The proposed actuation framework offers a model-free alternative to conventional control approaches, bypassing the complexities of modeling reconfigurable TDCMs.