Time Delays And Scheduling Analysis Of Networked Control System

A major trend in modern industrial and commercial systems is to integrate computing, communication, and control into different levels of machine/factory operations and information processes. These new distributed control systems are called Networked Control System (NCS). The change of communication architecture from point-to-point to this common-bus approach, however, introduces different forms of time-delay uncertainty in the closed-loop system dynamics. These time delays come from the time sharing of the communication medium and introduce many fresh meanings to traditional control theories and methodologies. For these reasons, this topic has been the hot research direction in control industry. Time delays and scheduling are two of the basic issues in the analysis, design and modeling of Networked Control Systems. Hence, this thesis focuses on these two issues.In the beginning of this thesis, it presents many problems in NCS research, and moreover, summaries the simulation methodologies of NCS. Here, TrueTime toolbox and its principle are presented.To understand the time delays in an NCS due to networked communication, it summarize the comparison of technical structure of several popular protocols in MAC layer, especially the characteristics of random access protocols—CSMA/CD and CSMA/AMP. Furthermore, the composition and modeling of network introduced are discussed in detail. As one of the most important conditions affecting time delays, the network traffic load is analyzed. Simulation and experimental studies further validate the advantages of CAN and switched Ethernet in real-time issue.Based on existent results on control network performance and scheduling in protocol layer,the thesis analyzes the scheduling algorithm of networked...