Research On Key Technology Of Cyber Physical Systems (CPS) In Coal Preparation Plant

Cyber physical system(CPS) is a kind of multi-dimension complex system that integrates computing, network and physical environment together. Through the organic integration and deep cooperation of computing, communication and control techniques, CPS realizes the real time sensing, dynamic control and information service of large engineering system. During earlier building stage of Xinlong Zhuang coal preparation plant the automation control has been realized, but the interactions among working procedures were rather weak. In such base, it is the key for the informatization of coal preparation plant to introduce new computing, communication and control techniques to realize the more closely fusion of information system and control system. In the thesis based on the conception of CPS combined with characteristic of coal preparation plant control system, the CPS model of coal preparation plant is built. Some key techniques in the CPS model are researched. The results can provide theoretic guidelines for applying CPS in coal preparation plant and building modern coal preparation plant with autonomic behavior.Firstly, according to the technological process a coal preparation plant CPS model based on partial order knowledge sharing is designed. Through dispatching partial storage to build knowledge base for each production unit, and setting the methods of knowledge asynchronous sharing and transmitting, the loose correlation of production units is realized.Combining the characteristics of CPS with complex network, and introducing random walk mechanism and small world based RLOC(Removing superfluous Links to Optimize the Cluster) topological optimization algorithm to the procedure of building topological structure of coal preparation plant CPS, the coal preparation plant CPS topological structure has the characteristic of scale-free and small world network, and at the same time has the feature of strong survivability.Task scheduling is the key point to link coal preparation plant CPS task plan with actual production. Combining Xinlong Zhuang coal preparation plant PLC(Programmable Logic Controller) control system, the thought of dynamic alliance is adopted to coal preparation plant CPS task scheduling. A CPS static scheduling model based on due date window is proposed. By introducing TS(Tabu Search) into the PSO(Particle Swarm Optimization) searching late period, the scheduling performance is enhanced. At the same time based on the dynamic characteristic of production environment of coal preparation plant a dynamic task scheduling method is also put forward for the situation of equipment exception and urgent task. Simulating results indicate the feasibility of the algorithm used for coal preparation plant CPS task scheduling.On the demand of real time data management of coal preparation plant a kind of feedback control framework is presented to realize the expected delay of transaction in real time embedding database system. Comparing with traditional real time database the method can control multiple interacted resources, and better balance the relationship of transaction time and data freshness to provide more effectiveness and robustness.Production parts have different demands on information inputs for trustworthiness and reliability. Therefore at last of the thesis a trust degree model and its evaluating method for coal preparation plant CPS network are built. Combining the factors of affecting trust, D-S(Dempster-Shafer) evidence theory is used. Through introducing environment parameters a computing flow is designed for coal preparation plant CPS trustworthiness. And suitable computing method for each part is given. The trust degree calculation is realized for coal preparation plant CPS.