Some problems of stabilization and output regulation of nonlinear systems.

Chen Zhiyong.Thesis (M.Phil.)--Chinese University of Hong Kong, 2002.Includes bibliographical references (leaves 54-57).Abstracts in English and Chinese.Abstract --- p.iAcknowledgement --- p.iiChapter 1 --- Introduction --- p.1Chapter 1.1 --- Nonlinear Control --- p.1Chapter 1.2 --- Global Stabilization --- p.2Chapter 1.3 --- Output Regulation --- p.3Chapter 1.4 --- Contributions of the Thesis --- p.4Chapter 2 --- Global Robust Stabilization of Cascaded Polynomial Systems --- p.5Chapter 2.1 --- Introduction --- p.5Chapter 2.2 --- Preliminaries --- p.6Chapter 2.3 --- Basic Results --- p.8Chapter 2.4 --- The Algorithm --- p.11Chapter 2.5 --- An Example --- p.14Chapter 2.6 --- Concluding Remarks --- p.16Chapter 3 --- Output Regulation of Singular Nonlinear Systems by Normal Output Feedback --- p.18Chapter 3.1 --- Introduction --- p.18Chapter 3.2 --- Preliminaries --- p.20Chapter 3.3 --- Main Result --- p.24Chapter 3.4 --- An Example --- p.34Chapter 3.5 --- Concluding Remarks --- p.35Chapter 4 --- Robust Output Regulation of Singular Nonlinear Systems --- p.37Chapter 4.1 --- Introduction --- p.37Chapter 4.2 --- Problem Description and Standard Assumptions --- p.38Chapter 4.3 --- A Preliminary Result --- p.40Chapter 4.4 --- Solvability of the Problem --- p.48Chapter 4.5 --- Concluding Remarks --- p.51Chapter 5 --- Conclusions --- p.52Bibliography --- p.54Biography --- p.5

Uniform semiglobal practical asymptotic stability for non-autonomous cascaded systems and applications

It is due to the modularity of the analysis that results for cascaded systems have proved their utility in numerous control applications as well as in the development of general control techniques based on ``adding integrators''. Nevertheless, the standing assumptions in most of the present literature on cascaded systems is that, when decoupled, the subsystems constituting the cascade are uniformly globally asymptotically stable (UGAS). Hence existing results fail in the more general case when the subsystems are uniformly semiglobally practically asymptotically stable (USPAS). This situation is often encountered in control practice, e.g., in control of physical systems with external perturbations, measurement noise, unmodelled dynamics, etc. This paper generalizes previous results for cascades by establishing that, under a uniform boundedness condition, the cascade of two USPAS systems remains USPAS. An analogous result can be derived for USAS systems in cascade. Furthermore, we show the utility of our results in the PID control of mechanical systems considering the dynamics of the DC motors.Comment: 16 pages. Modifications 1st Feb. 2006: additional requirement that links the parameter-dependency of the lower and upper bounds on the Lyapunov function, stronger condition of uniform boundedness of solutions, modification and simplification of the proofs accordingl

Path-tracking of a tractor-trailer vehicle along rectilinear and circular paths: A Lyapunov-based approach

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State feedback based fractional order control scheme for linear servo cart system

Fractional order control schemes are being actively investigated for various systems. Fractional order concept is incorporated in integral (I), proportional integral (PI), proportional derivative (PD) or proportional integral derivative (PID) controller to investigate the performance of different state variables of the system. These techniques are often used for the purpose of technology transfer but very scanty research has so far been conducted using state space approach. The current investigation is initiated to observe the effect of fractional order controller using state space approach for the system's performance while tracking the position and regulating the speed of a linear servo cart system. Integer order controller based on proportional derivative (PD) approach is also shown for comparison. Simulation responses are presented and analyzed, in this investigation. The superiority of state space approach based fractional order controller is shown in the results. The paper contains a literature review on several control techniques used to control position and speed of a servo-cart system. An over view of mathematical modeling of servo cart system and a description of a proposed fractional controller is presented in this paper. A brief description of integer order control scheme is also presented. Simulated results are compared and discussed for both fractional order controller and integer order controller at the end of this paper

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