Paul de La Sayette

“Advancing Human-Robot Collaboration: Achieving Compliance through Variable Impedance Actuators in Lightweight Cable-Driven Robots”

Advised by Prof. Kenneth Salisbury

Abstract: Traditional robotic systems have inherent limitations in their ability to interact safely with humans due to their rigidity and mass, even when complex control algorithms are used to as a layer of "software compliance". Variable Impedance Actuators (VIA) emerge as a potential solution by enabling the adjustment of a robot’s passive joint stiffness. This allows the robot to select between inherent compliance, such as for tasks involving unexpected contacts, or high stiffness, when precise position control is required. This work presents our innovative approach of integrating and using VIAs into a new generation of multiple degree of freedom cable-driven robots. By implementing VIAs within the cable system, we achieve dynamic control over the robots' stiffness while keeping a lightweight design. This offers a safer and more adaptable platform for physical human-robot collaboration. Our robots feature N+1 cables for N degrees of freedom, with each cable contributing to every degree of freedom, allowing us to use smaller actuators and fewer cables than current cabled VIA robots.