自动化立体车库管理系统的研究(英文文献+CAD图纸)
part. Until a product is completely manufactured, information about the product is maintained by fractals through their coordination and cooperation. Unlike in the holonic manufacturing system, there is no particular component in charge of the products in the FrMS.
6. Development of prototype agents Before developing all 18 agents of a fractal as described earlier in this paper, a DMA and an NEA have ?rst been developed as a prototype implementation. The major focus of this development was the implementation of the functions of MANPro. Each agent has been designed with UML and developed with AgletsTM [22,29]. AgletsTM is the JavaTM-based agent development tool developed by IBM Japan. Environments are provided on the host computers by specialized servers which understand the Agent Transfer Protocol (ATP) and provide security and other services. The most important reason to use a JavaTM-based language is to facilitate platform-independent systems. Furthermore, AgletsTM is an open source program so that programmers can customize their own programming environments while they develop agents. The latest version of AgletsTM supports Java2. Fig. 13 illustrates the procedure for creating DMA and NEA from Tahiti, an agent server. Users, however, can operate agents without the Tahiti program by developing and using a customized program similar to Tahiti. The ‘‘create’’ button displays the list of registered agents to the users. When a user chooses DMA from the list, a DMA is created as illustrated in Fig. 13. The ‘‘Make NEA’’ button belonging to the DMA is used to create an NEA.
Negotiations between the DMA and the NEA are performed based on the MANPro as illustrated in Fig. 14. As shown in the current address field of each DMA, each DMA is expected to be on a different (distributed) server. As shown in the figure, four prototype agents have been tested on the same machine (POSCIM) with different port numbers (e.g. 4434, 4444, 4445, 4446) for the ease of presentation. Similarly, the same system has been successfully tested on distributed machines. The current status display of the agents in Fig. 14 shows that an NEA has been created by a DMA (port: 4434), and it is currently traveling according to its traveling list. The status display also says that the NEA has just finished negotiating with a DMA (port: 4445), and it is about to physically move to another DMA (port: 4446). After ?nishing negotiations with all the other DMAs, it will be returned to the original place (DMA, port: 4434) and will submit the ?nal report to the DMA. The time taken for the NEA to travel these DMAs is less than a second, but will vary depending on the functions of the NEA. The execution time in a MANPro-based negotiation may be arguable by other researchers. However, owing to the rapid increase of computing power, the execution time will be signi?cantly reduced, and, therefore, it will not be a major burden in the near future.
 Fig. 13. The procedure for making DMA and NEA from Tahiti.
7. Conclusion
The FrMS has autonomy, ?exibility, and a high degree of self-similarity, and it is based on the concept of autonomous cooperating multi-agents referred to as fractals. The FrMS has many advantages that arise from fractal-specific characteristics including self-similarity, self-organization, and goal-orientation, particularly in a distributed and dynamic environment. The most outstanding function of the FrMS is the dynamic restructuring process, and it allows the FrMS to be more
Fig. 14. Negotiations between NEA and DMAs.
efficient and effective by reconfiguring fractals. In this paper, several fractal-specific characteristics and the DRP are described and modeled with UML diagrams. Agents for an FrMS are also described and modeled with UML. The use of UML allows not only an easy understanding of a system but also various other advantages mentioned in this paper. Through the dynamic modeling of the interactions among agents, an FrMS is now ready to be implemented containing several types of agents defined in this paper. This paper has also clarified the activities of agents based on inter- and intra-fractal activities. Information and messages regarding resources (equipment) are de?ned in detail along with exemplary equipment, and a method to deal with resource data and product data is presented. To test a new negotiation scheme for agents, the prototype agents (DMA and NEA) have been developed and tested based on the MANPro. The implementation and testing of a complete FrMS is left for further research.

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