Robotic Cell Scheduling with Operational and Process Flexibility

by

Hakan Gültekin
Bilkent University

A manufacturing cell in which the material handling is done by a robot is called a robotic cell. The objective is to find the part input sequence and the corresponding robot move sequence that jointly minimize the cycle time. In the current literature, the processing times are assumed to be fixed on each machine, although this assumption unnecessarily limits the number of alternative for the CNC machines.  In this study, we will investigate the additional flexibility introduced by the CNC machines. In the first part of this presentation we will go over the basics and the main assumptions of the robotic cell scheduling problem, and present our results for the 2-machine robotic cells. Next, we will consider more general m-machine case and propose a new robot move cycle which is not considered in the classical robotic cell scheduling literature. We will find the regions of optimality for this cycle and present a worst case performance bound for using the proposed cycle instead of the optimal one. Our results show that the proposed cycle is not only simple and practical but also gives the minimum cycle time for most of the cases.