| 英文摘要 | With the rapid developments in computer, network communication and control technologies, the networked control systems (NCSs) have been a growing trend in industrial automation systems for the purposes of distributed management and control. However, due to the properties of a shared network, especially the Internet and wireless networks, such as opening-up, interactivity, and decentralization, the feedback and control signals transmitted in NCSs are confronted with such problems as network security attacks. For the industrial NCSs, two types of attacks, deception attacks and denial of service (DoS) attacks, are considered. To guarantee the desired control performance when suffering from these attacks, the active mechanisms of prevention, detection and response have been proposed from the viewpoint of network communication and control theories in this thesis. The main work and achievements can be summarized as follows: (1) To achieve the confidentiality of the data transmitted in networked systems as well as the detection and response of deception attacks, a secure transmission mechanism (STM) is presented from a network communication point of view, which integrates the Data Encryption Standard (DES) algorithm, Message Digest (MD5) algorithm, and timestamp strategy. Then, a secure networked control system (SNCS) is designed based on the STM for the deception attacks in NCSs. To validate the SNCS, two experimental platforms are built: a Internet-based DC motor control system and a single linear inverted pendulum control system based on wireless metropolitan area networks (WMAN). Experimental results illustrate the effectiveness of the STM and SNCS. (2) To compensate for the adverse effects brought by the network communication constraints, such as random network time delay, packet disorder and dropout, a recursive networked predictive control (RNPC) method is proposed based on network round-trip time delays (RTTD). The stability condition of the closed-loop system is also derived based on the switched system theory. Then, on the basis of the analysis of the effects of deception attacks on the SNCS's performance, a secure networked predictive control system (SNPCS) is designed based on the STM and RNPC from the viewpoint of network communication and control theory. The SNPCS can provide the data confidentiality service, the detection of deception attacks, and the compensation for the adverse effects caused by deception attacks and network communication c... |
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