Cyclic robot scheduling for 3D printer-based flexible assembly systems

Abstract

This paper proposes and analyzes an efficient robot task sequence for a flexible assembly system that consists of multiple 3D printers, post-processing, assembly, inspection machines, and a material handling robot. The flexible assembly system, which has been built in many large cities in Korea, has been designed to fabricate customized products for start-ups or individuals. We consider cyclic scheduling of the system in which the robot repeats a certain sequence to produce identical products. We propose a robot task sequence to minimize the cycle time. The system behavior with the proposed robot task sequence is modeled with a timed event graph (TEG), and the optimality of the sequence is proved by analyzing the circuits in the TEG. The results are extended for producing multiple types of products simultaneously.