A Study On Robust Control For Linear Uncertain Timedelay Systems  Posted on:20020604  Degree:Doctor  Type:Dissertation  Country:China  Candidate:P G Jiang  Full Text:PDF  GTID:1118360032455081  Subject:Control theory and control engineering  Abstract/Summary:  PDF Full Text Request  It is always impossible to obtain accurate mathematics model for the practical industrial process control. The model under which the controller is designed is usually different to the real plant owing to model reduction, linear approximations and the ignoring of the dynamics difficulty for modeling, the changing of the operating environment and other unmeasurable disturbances. The difference which some measure can be given usually can be described as the uncertainties in the model arguments. Robust control, the control method considering such uncertainties when designing controller is a effective way to deal with the uncertain parameters. In the other hand, because of transmission process, largelag links and complicated online analyzer etc, a large number of industrial processes (in metal engineering, chemical engineering systems, biomedical systems and so on) can be modeled as timedelay systems. Systems stability and performance are always dominated by the delay phenomena, so the study of delay systems always attracts considerable attention in the control theory literature, in this paper, kinds of robust control problem for linear uncertain timedelay systems are studied in detail. Based on Lyapunov stability theory, Razumikhin stability theory and convex set theory, linear matrix inequality, matrix analyzing methods and convex programming are adopted in this paper. Robust stability criteria, the design methods of robust stabilizing controller and guaranteeing certain robust performance controller for linear timedelay system with normbounded uncertainties or convex polyhedron uncertainties are studied in this paper by delay independent method and delay dependent method. The main contents are as follows: Iv 1. For linear timedelay systems with normbounded uncertainties or convex polyhedron uncertainties, a sufficient and necessary delay independent robust quadratically stabilizable condition and the corresponding robust stabilizing controller designing methods are given in the terms of linear matrix inequalities. The results in this paper deduce a lager allowed upper bound of uncertainties comparing to previous results. 2. For linear timedelay systems with normbounded uncertainties or convex polyhedron uncertainties, a sufficient and necessary delay independent condition of quadratic stabilizability under certain robust H~? performance constraint and the corresponding robust stabilizing controller designing methods are given in the terms of linear matrix inequalities. The methods presented in this paper are more concise and less conservative comparing to the previous results. 3. The problem of robust stabilization for a class of linear systems with state and control delay, normbounded uncertainties or convex polyhedron uncertainties is discussed using delay dependent method. Methods of solving linear matrix inequalities under nonlinear matrix inequality constraint are also presented. 4. For a class of linear timedelay systems with normbounded uncertainties, the concept of system attenuance is introduced. A definite attenuance robust stability criteria, a sufficient condition for the existence of definite attenuance memoryless state feedback control law and the corresponding method of controller design are derived. The results are de...  Keywords/Search Tags:  linear systems, timedealy, uncertainty, continuous, robust stabilize, robust Hâˆž control, guaranteeing cost control, attenuance, saturating actuator, delay dependent, delay independen  PDF Full Text Request  Related items 
 
