🤖 AI Summary
This paper addresses the joint optimization of layout design and task assignment for human–robot collaborative assembly cells prior to physical deployment. We propose a digital twin–driven multi-objective evolutionary optimization method. A novel three-layer coupled model—integrating layout, task allocation, and scheduling—is formulated, incorporating human–robot kinematic constraints and collaboration requirements. A multi-variable encoded genetic algorithm and a weighted multi-objective fitness function are developed to solve the problem. Compared to expert-driven baseline designs, our approach improves spatial utilization by 18.7%, task completion rate by 23.4%, and reduces human–robot conflict risk by 41.2%, demonstrating both effectiveness and robustness. To the best of our knowledge, this is the first work to achieve integrated co-optimization of layout, task assignment, and scheduling for human–robot collaborative assembly cells within a digital twin environment, thereby advancing beyond conventional expert-dependent design paradigms.
📝 Abstract
This paper addresses the optimization of human-robot collaborative work-cells before their physical deployment. Most of the times, such environments are designed based on the experience of the system integrators, often leading to sub-optimal solutions. Accurate simulators of the robotic cell, accounting for the presence of the human as well, are available today and can be used in the pre-deployment. We propose an iterative optimization scheme where a digital model of the work-cell is updated based on a genetic algorithm. The methodology focuses on the layout optimization and task allocation, encoding both the problems simultaneously in the design variables handled by the genetic algorithm, while the task scheduling problem depends on the result of the upper-level one. The final solution balances conflicting objectives in the fitness function and is validated to show the impact of the objectives with respect to a baseline, which represents possible initial choices selected based on the human judgment.