自动化立体车库管理系统的研究(英文文献+CAD图纸)
from equipment and the ECA sends commands made by the TGA to the equipment.
3.2. Inter-fractal activity
A negotiation between fractals is the most important process in an FrMS because it is essential in order for the agents to make decisions and to process jobs autonomously and coherently.
Fractal Intra-fractal activity ? Input/output control ? Scheduling ? Task generation ? Real-time simulation ? Information management ? Job (task) processing ? Database control ? Equipment control ? Intra-decision-making
Inter-fractal activity ? Negotiation ? Goal-orientation process ? Dynamic restructuring process Fractal Intra-fractal activity
•••• Fig. 6. Intra- and inter-activity of agents.
Fig. 7. CNP-based negotiation vs. MANPro-based negotiation.
NEA is in charge of negotiation, which is created by DMA. To impose a negotiation ability on agents, the contract net protocol (CNP) proposed by Smith [26] is still widely used. However, the CNP is expensive in terms of network bandwidth when the negotiation process implies a heavy communication load. For this reason, the negotiation process in this paper follows the MANPro introduced by Shin et al. [27]. The MANPro applies the mobility and the cloning mechanism of an agent. The greatest advantage of the MANPro is the reduction of the network loads without disturbing the application process. As illustrated in Fig. 7, the communication loads between controllers can burden the system when the CNP-based negotiation is used. This is because the connections between controllers must be maintained at all times. On the other hand, the MANPro-based negotiation generates network loads only when an agent moves from the issuer to the participants. Therefore, it can eliminate the extra network operations in which agents have to monitor communication messages. While all communications between controllers are executed globally in the CNPbased negotiation, they can be performed locally without using network resources in the MANProbased negotiation. Performing negotiations locally can reduce the number of network messages (e.g. acknowledgments). The MANPro-based negotiation, therefore, is more beneficial for negotiations among agents.
Agents in the FrMS always pursue their own goals. If necessary, they issue a bid and negotiate with others to make a complete goal. The goal-formation process is the process of generating goals by coordinating processes among participating fractals and modifying them as necessary [13]. The GFA is the agent that exists for this purpose. The GFA receives an incomplete goal from a NMA and makes sub-goals or modifies the current goal of the fractal. During the goal-formation process, the GFA cooperate with the DMA and FSM. The dynamic restructuring process is the most important activity of agents in the FrMS. It is performed through complex tasks including negotiations, goal-formations, and task generation. The DRP is initiated by one of the agents in an organizer referred to as the REA. The DRP enables a system to optimize its structure by reconfiguring network connections between the components. If a fractal’s workload exceeds a certain limit, the REA starts the DRP with the aid of other agents. A new fractal may be created, or existing fractals may be reorganized as a result of the DRP. When the DRP is needed in the FrMS, fractals first change their network connections, and then reorganize their structures to be more effective. In order to perform the DRP stably, it is assumed that there is always enough hardware suitable for use as a controller in a system. More details on the DRP will be presented in Section 4.2.
4. Fractal-specific characteristics and UML models
Characteristics that differentiate an FrMS from other manufacturing
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