MAS-based production scheduling system for manufacturing cell-based workshop

Abstract

The task of production scheduling is to determine the detailed machining path, time, machine tool, etc., for every work piece, according to the production objective and constraints. It is also an important part of the manufacturing system. In this paper, the manufacturing cell-based workshop is described and its scheduling system structure is established based on MAS (multi-agent system) technology. Through the negotiation and communication of each agent, the machining path is determined and the machining sequence and start time are calculated by GA (genetics algorithm). The communication among agents uses the CORBA (common object request broker architecture) technology of the OMG (Object Management Group). The CORBA-based architecture of the communication is designed and some interfaces for the communication are listed. For the genetics algorithm, chromosome coding, fitness function, parameters selection, and the basic genetics operation including selection, crossover and aberrance, are described. The scheduling system also can deal with some abnormal conditions, such as machine tool failure and urgent tasks. Finally, two scheduling examples are given.