Workflow-based programming of human-robot interaction for collaborative assembly stations

In certain domains manual assembly of products is still a key success factor considering quality and flexibility. Especially when thinking of flexibility traditional, fully automated assembly using specialized robot stations is mostly not feasible for small lot sizes due to high costs for programming and mechanical adaptations. In the last years collaborative robots (cobots) entered the market to broaden the way for robot-assisted manual assembly. The idea was to use the robot for small repetitive tasks at the manual assembly station and keep the human factor for dealing with flexibility. Unfortunately most of the new cobots came with the same programming system as their ancient relatives. Thinking of human-robot collaboration these traditional approaches do not consider the human factor at the assembly station. Therefore, this paper presents a new approach, called Human Robot Time and Motion (HRTM) providing a modeling language providing generic basic elements which can be performed by a human worker or a robot. Correspondingly a workflow-oriented programming model and a prototypical development environment featuring BPMN and MQTT is presented.