A Methodological Framework to Assess Mental Fatigue in Assembly Lines with a Collaborative Robot

In the current manufacturing assembly lines, collaboration between human and robot plays a significant role in the final output of the assembly, be it performance, quality or overall reliability. In that regard, smooth collaboration between human and robot is required to minimize the probabilities of human-system error, potential loss of performance and quality, and minimize the risk of decision making mistakes. Mental fatigue, and more importantly the cognitive load, of human operators is a crucial aspect in decision making, potential of error during the task and the overall flow of the assembly process. This paper reports about the development of a methodological framework to assess mental fatigue during a collaborative assembly task. In this framework, general complexity of the process and assembly task is investigated, as knowledge of the dynamic and static complexity can be helpful in reducing mental fatigue and cognitive load. We validated the applicability of the proposed frame in a real based collaborative assembly process.