Cobot Integration for Large Parts Picking in Assembly

Cobots are increasingly used as co-workers, relieving human workers from performing physically demanding tasks, commonly encountered in assembly systems. Assembly processes generally consist of two primary tasks: the picking-and-placing of components and the actual assembly. While the latter adds value to the final product, the former does not and should be minimized wherever possible. This paper focuses on the integration of a cobot into an assembly station for the picking-and-placing of large and heavy components. Such components are often stored in locations far from the operator’s workstation, resulting in increased task execution times. A three-step methodological approach is proposed, considering the physical characteristics of the components, with the goal of minimizing the overall makespan by optimizing task allocation between human operators and the cobot through a mathematical model. The proposed approach is then applied to a case study, comparing a fully manual scenario with a collaborative scenario, achieving an 18.6% reduction in makespan in the collaborative scenario, thereby validating the industrial viability of the proposed methodology. Additionally, an economic feasibility analysis of the investment was conducted, resulting in a payback period of 2.24 years, which falls within the acceptable range for financial viability in industrial systems.