Safety-oriented Teleoperation Framework for Contact-rich Tasks in Hazardous Workspaces

This paper proposes an admittance controller-based teleoperation system for contact-rich tasks. Based on the analysis of the motivating task (deposited iron lump removal task in the steel mill), the system concept is focused on the practical aspects of the system, and various components are combined to enhance the safety of the teleoperation of the robot. To connect the large inertia difference between the teleoperated robot and the command device, the admittance control is utilized in the teleoperation system, and the virtual spring saturation is adapted with the damping injection to ensure safe motion during the task. Lastly, the inertia and damping adaptation rule based on the contact force frequency is developed so that the system can selectively dissipate energy when the system shows oscillatory behavior. The proposed techniques have shown their effectiveness through the experiments. Although this study has started from a specific target, it suggests a practical solution for various contact-rich teleoperated tasks in the hazardous industrial workspace.