Design of an Energy-Aware Cartesian Impedance Controller for Collaborative Disassembly

TL;DR

This paper presents an energy-aware Cartesian impedance controller designed for safe and effective human-robot collaborative disassembly, incorporating energy management techniques to ensure passivity and safety during unplanned interactions.

Contribution

It introduces an energy-aware impedance control algorithm with energy scaling, damping injection, and an augmented energy tank to improve safety and performance in collaborative disassembly tasks.

Findings

The proposed controller maintains safety during contact losses and unexpected interactions.

Experimental results show improved safety and efficiency over standard controllers.

The algorithm demonstrates high potential in real-world disassembly scenarios.

Abstract

Human-robot collaborative disassembly is an emerging trend in the sustainable recycling process of electronic and mechanical products. It requires the use of advanced technologies to assist workers in repetitive physical tasks and deal with creaky and potentially damaged components. Nevertheless, when disassembling worn-out or damaged components, unexpected robot behaviors may emerge, so harmless and symbiotic physical interaction with humans and the environment becomes paramount. This work addresses this challenge at the control level by ensuring safe and passive behaviors in unplanned interactions and contact losses. The proposed algorithm capitalizes on an energy-aware Cartesian impedance controller, which features energy scaling and damping injection, and an augmented energy tank, which limits the power flow from the controller to the robot. The controller is evaluated in a real-world flawed unscrewing task with a Franka Emika Panda and is compared to a standard impedance controller and a hybrid force-impedance controller. The results demonstrate the high potential of the algorithm in human-robot collaborative disassembly tasks.