استفاده از روش چند عاملی در سیستم تولید انعطاف پذیر چند بخشی

In the highly competitive market, cooperative multi-agent transaction and negotiation mechanism have become an important research topic. This paper uses multi-agent technology to construct a multi-section flexible manufacturing system (FMS) model, and utilizes simulation to build a manufacturing environment based on JADE framework for multi-agent to combine with dispatching rules, such as shortest imminent processing time (SIPT), first come first serve (FCFS) earliest due date (EDD), and Buffer Sequence. This paper finds that using multi-agent technique for multi-section FMS model can enhance the production efficiency in practice. Meanwhile, in this study, multi-agent systems combined with dynamic dispatching can be used to identify the best dispatching rules combination for achieving largest throughput, and thus it can provide the reference for production scheduling in advance.

With the increasingly diversified market demands for small batch production, customized manufacturing mode must be employed so that the production system, production line and procedures can be adjusted flexibly to manufacture various kinds of products. Flexible manufacturing system (FMS) is an automated production mode most suitable for the aforementioned requirements, and has been valued in the manufacturing industry. It incorporates advanced computer application systems, such as Material Requirement Planning (MRP), Group Technology (GT), Computer Aided Process Planning (CAPP) and Multi-Processing Planning, ranging from ordering and material processing to delivery under system monitoring and resource assignment. This process is planned comprehensively to shorten the processing time and saving the cost. With the recent advancement of information technology, Artificial Intelligence (AI) has been developed prosperously, so multi-agent technology has attention of researchers. The concept of agent has been applied to FMS, and the resource allocation for the manufacturing system is analyzed and discussed through the negotiation, coordination and cooperation mechanism among agents. In Smith (1980) proposed a multi-agent system – Contract Net Protocol (CNP), for resolving the contest of resources in a cooperative manner. This is a commonly-used coordination mode whereby the agents can resolve the resource allocation through negotiation and coordination based on Contract Net Protocol. Although there have been many researches focus on applying multi-agent technique on FMS. However, to the best of our knowledge, there is no literature of applying multi-agent technique on multi-section FMS. This paper applies multi-agent technology to multi-section FMS controller design, in order to build an agent-based control mode to improve the availability of machines, shorten the manufacturing time and increase the capacity. The objectives of this paper are to build a multi-agent based FMS cell controller via software agent technology, and to find the best dispatching rules combination for achieving largest throughput in a real case of multi-section FMS.

As compared with single-section FMS, the multi-section FMS features more complex operation, more product categories and more flexible manufacturing process, making system control and dispatching more important to the performance of manufacturing system. With introduction of the concept of agent technology, the multi-section FMS combines the agent technology with the control modules of various machines, and establishes a perfect simulated manufacturing system based on the planning of manufacturing modes. The message transfer and coordination among agents is made possible through the communication language, or through a coordination mechanism based on the contract network in the event of conflict of assigned tasks. This can select the priority machines and deliver services for maximizing the overall benefits of the system and efficient allocation of system resources. Multi-section FMS (Cell Controller) exchanges information with multi-agent system (JADE) through network technology, but many manufacturing processes or system status have to be provided from database. The advantage of agent system is that it can prevent the decline of system stability, shorten the development time and increase the operating efficiency. Moreover, the agent technology can sharpen the enterprises’ competitive edge by introducing new technologies or new algorithms quickly and stably. Thus, establishing a perfect agent system and defining its coordination criterions can guarantee satisfactory operating capacity while the tasks assignment of manufacturing system is not limited to certain algorithm or mechanism. With the introduction of agent technology, the existing manufacturing system is only required to handle partially the hardware assignment commands, making it possible to shorten greatly the development time and reduce the maintenance burdens. Limited literatures pay attention to the control of multi-section FMS. This is the first paper to apply multi-agent technique in multi-section FMS. This study integrated the multi-agent system with multi-section FMS based on the established agent knowledge base. It is suggested that the dispatching rules should be applied to the optimal combination in various sections, and independent agents should take charge of judging the scenarios of dynamic rules for increasing the system efficiency.