Controller Synthesis Of Interval Type-2 T-S Model-based Networked Systems Under Cyber Attacks

Fuzzy control theory can deal with the influence of the nonlinear systems flexibly and conveniently.It has become one of the main methods to deal with nonlinear systems in the control field.Since the advent of the interval type-2 fuzzy control theory,the application of the fuzzy control has been promoted.Because it can not only deal with the uncertainty of nonlinear systems effectively,but also greatly reduce the calculation amount of processing problems,which makes the interval type-2 fuzzy control systems have been widely used in various fields.With the development of information technology,networked control systems have gradually become one of the hot research issues in the field of control science.However,due to networked sharing,the system may be subjected to malicious network attacks,resulting in system performance degradation.Therefore,the security of networked control systems has aroused the attention of many scholars.Based on the controller design and analysis of interval type-2 fuzzy networked control systems under the influence of various network attacks,this thesis mainly includes the following three parts:Part one:The robust H∞ control problem of the interval type-2 fuzzy networked control systems under replay attacks is studied.Firstly,the attack models of the replay attacks and the elastic triggering strategy suitable for replay attacks are given,and then the model of networked control systems based on the interval type-2 fuzzy system is presented.Finally,by constructing an improved L-K functional,the controller design method which can satisfy the robust H∞performance is derived by means of the inequality reduction technique,matrix decomposition and free weight matrix method.The final simulation proves that the system can run safely under the control of the designed controller when suffering from replay attacks.Part two:The H∞ control problem of singular interval type-2 fuzzy networked control systems under the influence of the Denial of Service(Dos)attacks is studied.Firstly,the models of the singular interval type-2 fuzzy networked control systems and Dos attacks are given,and then the improved elastic triggering strategy to handle with the Dos attacks is given.Finally,by constructing a class of L-K functional containing triple integrals and using Jensen inequality,reciprocal convex combination theorem and matrix decomposition technique,the sufficient conditions for the system to satisfy the performance of are derived.Due to the introduction of triple integrals,the system is relatively less conservative,which makes the system can tolerate stronger network attacks.Part three:The security control problem of interval type-2 fuzzy networked control systems under multiple network attacks is studied.By introducing a hybrid triggered scheme,the system can deal with multiple network attacks including Dos attacks and deception attacks at the same time.Firstly,the models of Dos attacks and deception attacks are given,and the hybrid triggered scheme is used to model the system.We assume that the attacks obey Bernoulli distribution.Then the sufficient conditions for the system to be asymptotically stable are derived by constructing an improved L-K functional.Because more time delay information is introduced in the construction of functional in this chapter,which further reduces the system conservatism.