Research On Multi-Agent Based MES Scheduling

Scheduling is one of core function in Manufacturing Execution System(MES). The rationality of scheduling is vital for successful MES implementation in an enterprise. Aiming at the job-shop scheduling in MES, multi-agent theory is applied to the modeling of scheduling system and the design of scheduling method. It enhances the flexibility, reactivity and expandability of scheduling system, adapts the system to complex manufacturing environment, and improves the practicability and effectiveness of MES.Firstly, the characteristics of scheduling in MES are analyzed. And then, a scheduling framework based on multi-agent system is developed in the thesis. The structure and function of each agent in the framework are designed, and the mechanisms of communication and collaboration among these agents are probed. Under the framework, the scheduling methods based on multi-agent are described. The concepts of scheduling characteristic information and scheduling characteristic value are proposed, and restriction maintenance method is designed. After analyzing the characteristics and applicability of various scheduling methods, a combinatorial scheduling method is designed to achieve the best effect of scheduling methods. The characteristics of various disturbances in scheduling are analyzed, and the responsive mechanism to disturbances is established, based on which dynamic scheduling is achieved. Through man-machine interaction, computers dispose foreseeable and routine tasks, while human dispose uncertain and unconventionality tasks. As a result, human and machine are balanced properly, and the efficiency of scheduling is improved. More importantly, the new scheduling method is suitable for dynamic shop floor environment. Finally, a case study is provided to validate the proposed scheduling methods.Taking a cooperative factory as application background, the project team have designed and developed an agile MES software(AMES V1.0). The system framework, network framework, information flow and develop environment of AMES are presented. The main functions of AMES are stated, including modeling of manufacture resource, task management, the simulation and supervision of production process and device management. The running of AMES needs an integration environment. Networked Collaboration Manufacturing System(NCMS) is integrated by various manufacturing resources. The framework and component of it are presented. As a function node of NCMS, AMES was implemented successfully and passed the running test.