Development of a balanced decoupling unit for a safe automated screwing process during human-robot-cooperation

The paper presents an automated screwing application inside a robot cell with human-robot-cooperation. It describes the use case and how the design challenges for process reliability and safety have been addressed from concept idea to the real set up. A focus is thereby set on the safety implementation, which is enabled by the development of a balanced decoupling unit, which enables force limiting at the end-effector during physical contact. The decoupling unit is implemented for the application with the screwing tool and is designed according to functional safety requirements. Its usability is validated in appropriate force measurements (according to ISO/TS 15066) and evaluated on its performance characteristics for the productivity of the robot application.