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Robust Dissipative Control For T-S Fuzzy Systems And Its Application

Posted on:2011-12-25Degree:DoctorType:Dissertation
Country:ChinaCandidate:Y J LiFull Text:PDF
GTID:1118360332958001Subject:Control Science and Engineering
Abstract/Summary:PDF Full Text Request
Nonlinearity, time delay, and uncertainty can be found in various engineering sys-tems, the existence of them can bring about a series of problems, and researches on theseproblems have always been focused and difficult in control field. Since the 1980s, non-linear control theory has been greatly developed, in which Takagi-Sugeno (T-S) fuzzycontrol method combines the expert experience and the traditional control theory. It is ap-plicable to many nonlinear systems, and it has many good characteristics, such as strongrobustness. It has gradually become an important method on research of complex non-linear system. The existence of time delay usually worsens system performance or evencauses system to be unstable. So, the researches on time-delay systems have great the-oretical and practical significance. On the other hand, passivity and dissipativeness areimportant concepts in systems control theory, which are more generalized stable concepts,and they have played an important role in system, circuit, network, and control engineer-ing and theory. Therefore, the robust passive and robust dissipative researches on T-Sfuzzy systems have the important theory and application significance.Based on Lyapunov functional method, by using linear matrix inequality (LMI), thisdissertation studies the problems of robust stability, robust passive control, robust dissipa-tive control, and multi-objective control for uncertain T-S fuzzy systems. Moreover, thedesigning problem of missile control system is studied based on the proposed methods.The parametric uncertainty in this dissertation is assumed to be norm bounded or its gen-eralized form, and such T-S fuzzy model can approximate any uncertain nonlinear systemat any precision. The main work and contribution of this dissertation are listed as follows:1. In the dissertation, the problem of robust passive control for uncertain continuousT-S fuzzy time-delay systems is studied. Based on Lyapunov theory, we present designmethods of state-feedback passive controllers, which can guarantee that closed-loop sys-tems are robust stable and satisfy the passive performance in terms of LMIs.2. In the case of current researches of uncertain discrete T-S fuzzy time-delay sys-tems, the passive control for uncertain discrete T-S fuzzy time-delay systems is pro-posed. Based on Lyapunov stability theory, sufficient conditions on the existence ofdelay-independent and delay-dependent robust passive controllers are derived, respec- tively. And controllers are designed in terms of LMIs.3. Passive problems in 1 and 2 are extended to dissipative problems. Based on Lya-punov stability theory, the sufficient conditions on the existence of delay-independent anddelay-dependent robust dissipative controllers are given, respectively. And the controllercan be obtained by solving a set of LMIs, which is easily implemented in engineering.4. Multi-objective control problems of uncertain continuous T-S fuzzy systems areconsidered. Aiming at the uncertain continuous T-S fuzzy systems which have moregeneralized uncertainty structure, based on Lyapunov stability theory, the problems ofregional pole assignment under passive (dissipative) performance constraint are studied.By solving a feasible problem of LMIs, sufficient conditions on the existence of state-feedback controllers which satisfy the multi-objective requirements are given. Further-more, the specific forms of the controllers are given. The obtained controllers can guar-antee that for all uncertainties, the poles of the closed system are in expectation region,and the closed system satisfies the given performance.5. Applying the control method proposed in this dissertation, the problem of de-signing a certain missile control system is studied. Firstly, the mathematical models ofthe pitch/yaw channel and the roll channel are given. Based on the mathematical mod-els, T-S fuzzy models of the missile control system are established. Then, by solvinga set of LMIs, feedforward and feedback controllers are obtained, the controllers canguarantee that the missile control system is asymptotically stable and satisfies the givenperformance. Simulation results demonstrate the effect of the proposed method.
Keywords/Search Tags:T-S fuzzy time-delay system, robust dissipative control, robust passive con-trol, multi-objective control, linear matrix inequality
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