Research On Data Aggregation And Distribution Mechanism For Cyber-Physical Systems

Cyber-Physical System (CPS) is an integrated system calculation process, control process and communication.process. Through network technologies, the CPS builds the connection between the physical world and a computer system, and realizes information sharing between the change of the physical environment and the calculation process, so as to implement the awareness of real-time changes of the physical world and control.There are two basic requirements of CPS, one is where to find the required data and the other one is to ensure the data can be transmitted to the user in time. From this perspective, the CPS can be regarded as a complex system based on data transmission system. These packets are generated by data direct transport mechanism between the nodes which have sensory ability and users, which have redundant and useless information. This not only increases the network load pressure, but also can’t guarantee the real-time ability of sensory data transmission.To solve the above problems, this thesis first does research about sensory data transmission mechanism for CPS, find hierarchical property of CPS and analyzed from the system structure and data features. On the basis of analysis of running process of CPS, considering hierarchical characteristics this thesis proposes a data transmission model, Hierarchical Transmission Model (HTM). This thesis presents two kinds of data transmission mechanisms of data aggregation and distribution based on HTM. The data aggregation processes are the transmission mechanism based on geographic location and sensor types. The data distribution transmission mechanisms are composed of active and passive distribution transmission mechanisms.The new data transmission mechanisms could not only decrease the number of data packets over the Internet and redundant and useless information, but also reduce the time cost of network transmission. These experiments in terms of time effectiveness, load adaptability, the transmission time affected by the frequency change, behave better than the sensory data direct transport mechanism. It effectively alleviates the problems between number of data packets and effectiveness of data transmission, and better satisfies the requirements of CPS application service oriented.