Abstract:

In order to effectively schedule multi-manipulator manufacturing cells with residency constraints and differentproduct types,a bottleneck-based push-pull algorithm is presented. In the investigation,first,the problemdomain of the manufacturing cell scheduling is discussed. Next,the mathematical models with a scheduling objectiveof minimum system Makespan are established. Then,based on these models,a heuristic scheduling algorithmbounded by the bottleneck workstation is proposed to optimize manipulator movements by adopting backtracking andrecursive methods and to reduce the residency time on workstations. By combining with the time buffer concept onthe shared workstations,the push-pull algorithm helps to implement robot conflict-free and deadlock-free at thesame time. Finally,the bottleneck-based push-pull algorithm is verified and is compared with the conventional pullalgorithm through simulations. The results demonstrate that the proposed algorithm can implement the scheduling ofmulti-manipulator manufacturing cell with residency constraints and different product types,and has a better performancethan pull algorithm.

Key words: manufacturing cell, residency constraint, multi-robot, scheduling algorithm