Research On Fault-Tolerant Control Of Networked Control Systems

With the rapid development of computer control technology, control systems are being more and more widely applied, since the controlled plants are more complex than ever, control systems will be more distributed and intellectualized in the future. At the same time, there have been quite great development in the research of shared data network technology, because of the merit of network, more researchers are putting emphasis on the research of applying network technology into industry control and industry automation. The primary advantages of an NCS are reduced system wiring, ease of system diagnosis and maintenance, and increased system agility, so the more reliable networked control systems will be widely used in control systems design.Fault-tolerant of Networked Control Systems is discussed from the aspects of control and network, we mainly consider the design of the controller and the improvement of network security to improve the fault-tolerant performance of Networked Control Systems. We give the technology measure of ensuring network security firstly, then we point out that the main reason network being inclined to be attacked is the disfigurement of network structure and the disfigurement of operation system, then several attacks and corresponding countermeasure are presented, for some ordinal attack, the technology countermeasure is also discussed.Then considering the security problem, intrusion detection and firewall design which ensuring network security are presented. The intrusion detection engine is given firstly, then two improved intrusion detection algorithm are presented, the experimental results prove the validity of the algorithm, then we present the overall implement of intrusion detection system. Since firewall can prevent unauthorized accessing, its aim is to protect our network and system from being infringed, so it is important in ensuring system security. The key technology of firewall is presented first, then a fault-tolerant algorithm is discussed, this algorithm can ensure the working order of whole system even with firewall dysfunction; then we give the construction process of Screening router firewall.Then we present the method to compensate delay and packet dropout of system. By searching for the optimal model, we enlarge the permissible sample period of system and diminish the number of packet transferred and improve the fault-tolerant performance of...