Research On Modeling For Contract Net Protocol Based On Object-Oriented Colored Petri Net

Collaboration is one of the most important issues in the Multi-Agent System (MAS). But the interaction is the basis for collaboration. The Contract Net Protocol (CPN) is a classical interactive protocol, which has been proposed by Randall Davis and Reid G Smith. It borrows ideas from invitation for bid in commercial activity, and it has been applied to tasks and resources distribution. The CPN has become the key technology in collaboration of MAS. In the CPN, the formation of task, distribution and Manager Agents and Contractor Agents are dynamically generated. It is flexibility, and has been widely used in MAS. But the classical CPN, there are many deficiencies, such as the excess communication and so on. Although now many researchers have proposed many methods to expanding and improving it, most of them studied by the logic symbols and the friendly cooperation. The logic symbols are rather obscure and also uneasy to program. At the same time, in the non-face-to-face, dynamic network environment, each Agent's honesty is not same. This will lead to insecurity in the interactive among the agents. Therefore, in order to adapt the dynamic, complex and volatile environment better, it is nessary to research a safe, simple and understandable model to the CPN.So in this paper, we proposed SDCNP (Secure-Dynamic Contract Net Protocol) model using OOCPN (Object-Oriented Colored Petri Net), which is combined by Object-Oriented and Colored Petri Net to meet this needs. First, from the micro, with belief, desire and intention of BDI Agent which is proposed by Anand S.Rao and Michael P.Georgeff, also used other researchersbresearch results" Trust and Threshold, we model the internal structure of the interaction of the individual. And then use the analytical method of the Petri Net to analyze the model and make sure the model has the boundedness, security, reachability and liveness. Sencond, from the macroscopy, we improve the interaction process based on CPN. From two aspects, which are ! law5 and ! morality5 to guarantee the secrity of CPN. On the one hand, to punish the dishonest actions; on the other hand, according to learning and evaluating its own action and taking full advantage of its historical information. And then it can choose a beneficial action to execute. Through the two aspects of security assurances, reduced the disavowal to its own action, enhanced the security of the CPN. At last, through the simulation to different models using REPAST, the analysis and comparison indicate that the improved CPN, which is SDCNP, has a certain high efficiency and security.