Research On Key Technology Of Intelligent Waterway Transportation Information System Based On Multi-Agent

Waterway Transportation is the important part of transportation system.,plays important role in national economy, foreign trade and economic development of regional society. Along with the development of information technology, waterway transportation, especially in Changjiang River, has been developing rapidly in aspect of information infrastructure, application system and resource of datum, and has appeared important function gradually. But meanwhile, it has also been emerged that transportation information systems all are dispersed and isolated, information can't be exchanged and shared so that they couldn't be used effectively. Therefore, it is the inevitable trend to integrate marine service, share marine information and fulfill task cooperation. The core idea of intelligent waterway transportation system is to establish integrated waterway transportation manage system, the system should include all area of waterway transportation so that traffic infrastructure and social resource could be used sufficiently, and shipping could be more safe and efficient. The final aim is to fulfill socialization and intelligence of waterway transportation. Therefore, based on the idea, the paper brings forward to construct architecture of intelligent waterway transportation information system (IWTIS) in multi-agent technique, and make special research on the key techniques of multi-agent system in IWTIS.The paper analyses information sources and organization structure of Changjiang transportation system, summarizes information flow, and elicits logic frame of processing marine information. In view of the frame features, discusses the feasibility of using multi-agent technique in IWTIS.Improving the federation structure of MAS,the paper puts forward a new multi-agent structure, C-M structure model.In the model, by decomposing function vertically and horizontally,the whole system is divided into small sub-systems which are easy to realize, control function is distributed to different levels, complicated tasks could carry out with local cooperating and negotiating. Consequently, curse of dimensionality and reliability of large systems could be resolved. Based on C-M model, the paper constructs two kinds of IWTIS architecture.One is based on partition of spatial area, the other one is based on partition of service function. The characteristics and applicability of the two is discussed. Whereafter, the paper designs the typical structure of implement-layer and cooperate-layer respectively, makes formalized definition of elements in the structures and code realization of primary functions using object-oriented developing language.Having the features of the distributed, dynamic and heterogeneous, it will directly influence IWTIS performance that of agents cooperating ability, entireness consistency and self-adaptability of structure, so they are the important indexes for evaluating intelligent level of the system. As a relatively mature negotiation mechanism, CNP (Contract-Net-Protocol) is emphatically studied in the paper. Using CNP for exchanging information in IWTIS,the main problem would be mass of communication, and it would induce complication of decision-making and debasement of decision-making efficiency. Considering it, the paper introduces the concept of commitment, proposes improved bidding strategy based on commitment to improve bidding strategy based on acquaintance, and then brings out the strategy of bids assessment based on commitment credit and ability. Aiming at conflict and competition of interest of agents, a negotiation algorithm of multilateral-multi-round is put forward based upon game theory. The algorithm does not depend on the agents'global knowledge on benefit, and makes full use of local knowledge of agents to resolve conflict and get to cooperation.In the end, aiming at present situation and demand of ship traffic manage for Changjiang River, the paper sets up the traffic flow monitor and guidance system based on IWTIS architecture, designs the structure and function, analyses key techniques and solution, and then makes simulation experiment in laboratory environment. Experimental results show that cooperating among agents could control traffic flow effectively and avoid vessel traffic jam, consequently, improve shipping safety and traffic efficiency.