Variable Stiffness Control of an Artificial Cable-Driven Manipulator

This paper presents a novel cable-driven 7-degree-of-freedom redundant anthropomorphic manipulator designed to address the challenge of adjustable stiffness in robotic arms. By exploiting the inherent properties of cables, the manipulator achieves variable stiffness across diverse poses and utilizes redundancy to select optimal configurations for a wide range of tasks. Comprehensive stiffness models for the shoulder, elbow, and wrist joints are developed, accompanied by a sophisticated variable stiffness controller. Furthermore, a manipulability index is introduced to quantify and optimize the manipulator's operational capability and flexibility. Experimental results demonstrate the manipulator's capacity to precisely adjust stiffness and enhance dexterity, underscoring its potential for complex tasks and providing valuable insights into the design and control of cable-driven manipulators.