Robotic cell scheduling with operational flexibility

Abstract

In this thesis, we study the problem of two-machine, identical parts robotic cell scheduling with operational flexibility. We assume that every part to be processed has a number of tasks to be completed in these two machines and both machines are capable of performing all of the tasks. The decision to be made includes finding the optimal robot move cycle and the optimal allocation of tasks to these two machines corresponding to this robot move cycle that jointly minimize the cycle time. We proved that 1-unit robot move cycles are not necessarily optimal with this definition of the problem any more and that according to given parameters either one of the 1-unit robot move cycles or a 2-unit robot move cycle is optimal. We proposed a new robot move cycle, which is a result of the assumption of operational flexibility. This cycle is not only simple and practical but also dominates all of the common cycles reported in the literature. Finally, we considered the change of layout and showed that the cycle time of the proposed cycle can be further reduced by a change in the layout while the cycle times of all other cycles remain the same. Keywords: Robotic cell, cyclic scheduling, automated manufacturing.