Collaborative Patterns for Workflows with Collaborative Robots

Collaborative work environments have gained more attention in manufacturing in recent years, in particular with the development of collaborative robots (cobots), a special type of industrial robot that is built for the safe interaction between humans and robots. Recent advances have shown that there are several collaboration scenarios between humans and robots, such as, synchronized, cooperation, collaboration and coexistence. So far, most literature focuses only on the collaboration between one human and one robot. However, literature also predicts that there will be more collaboration scenarios with one or many humans collaborating with one or many robots. Furthermore, literature on collaboration scenarios often focuses only on a generic process perspective and does not detail tasks nor other aspects. In this paper, we aim to address these gaps by investigating collaboration scenarios for one to many and many to many relations between robots and humans in workflows. First, we formalize the collaboration pattern and its types (synchronized, cooperation, collaboration and coexistence). Our approach allows for the specification of time-based, spatial and functional constraints at task level in collaborative work environments. Second, we demonstrate our findings with a proof-of-concept implementation that consists of a workflow system, a cobot simulation and a communication and data platform. Third, we evaluate our model with altogether seven use cases (e.g., spot taping). The results show that the patterns can be applied for the specification of collaboration scenarios in modern, process-oriented work environments. For future work, we would like to investigate questions on process modeling and visualization of collaborative patterns.