A general cost model to assess the implementation of collaborative robots in assembly processes

Abstract

In assembly processes, collaborative robots (cobots) can provide valuable support to improve production performance (assembly time, product quality, worker wellbeing). However, there is a lack of models capable of evaluating cobot deployment and driving decision-makers to choose the most cost-effective assembly configuration. This paper tries to address this gap by proposing a novel cost model to evaluate and predict assembly costs. The model allows a practical and straightforward comparison of different potential assembly configurations in order to guide the selection towards the most effective one. The proposed cost model considers several cost dimensions, including manufacturing, setup, prospective, retrospective, product quality and wellbeing costs. The cost estimation also considers learning effects on assembly time and quality, particularly relevant in low-volume and mass customised productions. Three real manufacturing case studies accompany the description of the model.

Integrating Bio Principles in Assembly Task Design to Enhance Symbiotic Human-Robot Collaboration

“…Understanding the essentials of SHRC lays the groundwork for appreciating the diverse nature of interactions within HRC, particularly in assembly processes. Barravecchia et al (2023a) elaborate on this by exploring various symbiotic human-robot relationships, framing them in a scheme drawn from the natural symbiotic context, as described below (see Fig. 1):…”

“…The essence of HRC lies in orchestrating harmonious and positive symbiotic relationships between human operators and robots (Simões et al, 2022). A positive symbiotic relationship, in this context, indicates an interaction where both human and robot bene t from each other's distinct capabilities, thereby contributing to the overall e ciency, productivity, and safety of the collaborative tasks (Barravecchia et al, 2023a). While the importance of such a symbiotic interaction is acknowledged, its practical realization presents several challenges and opportunities (Gervasi et al, 2020;Li et al, 2021).…”

“…This prevalent orientation has overshadowed the crucial aspect of how assembly tasks should be allocated and be collaboratively executed to optimize the symbiotic exchanges between the human and the robot (Barravecchia et al, 2023a). This gap in the existing literature underscores the need for a methodological framework that delves into the protocols of task execution, aiming to maximize the positive symbiotic exchanges in a HRC setting.…”

“…This might occur in scenarios where the tasks performed by humans and robots are so distinct and independent that their collaborative interaction doesn't meaningfully change the output or process. This taxonomy can be a useful reference point for designing and analyzing symbiotic relationships (Barravecchia et al, 2023a).To fully realize and enhance SHRC, it is critical to comprehend the symbiotic factors that in uence the relationship.Barravecchia et al(2023a) identi ed three distinct symbiotic factors (action, guidance and protection) and their corresponding dimensions relevant to HRC.The action factor involves the exchange of concrete actions required for task completion. For example, in an assembly process, a robot may position parts while a human operator secures bolts, exemplifying an integral exchange of actions for task completion.…”

“…This might occur in scenarios where the tasks performed by humans and robots are so distinct and independent that their collaborative interaction doesn't meaningfully change the output or process. This taxonomy can be a useful reference point for designing and analyzing symbiotic relationships (Barravecchia et al, 2023a).…”