다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

Disturbance-observer-based control (DOBC) and related methods have been researched and applied in various industrial sectors in the last four decades. This survey, at first time, gives a systematic and comprehensive tutorial and summary on the existing disturbance/uncertainty estimation and attenuation techniques, most notably, DOBC, active disturbance rejection control, disturbance accommodation control, and composite hierarchical antidisturbance control. In all of these methods, disturbance and uncertainty are, in general, lumped together, and an observation mechanism is employed to estimate the total disturbance. This paper first reviews a number of widely used linear and nonlinear disturbance/uncertainty estimation techniques and then discusses and compares various compensation techniques and the procedures of integrating disturbance/uncertainty compensation with a (predesigned) linear/nonlinear controller. It also provides concise tutorials of the main methods in this area with clear descriptions of their features. The application of this group of methods in various industrial sections is reviewed, with emphasis on the commercialization of some algorithms. The survey is ended with the discussion of future directions.

/pdf/disturbance-observer-based-control-and-related-methods-an-795w6vym5o.pdf

Disturbance-Observer-Based Control and Related Methods—An Overview

This paper studies a number of quantized feedback design problems for linear systems. We consider the case where quantizers are static (memoryless). The common aim of these design problems is to stabilize the given system or to achieve certain performance with the coarsest quantization density. Our main discovery is that the classical sector bound approach is nonconservative for studying these design problems. Consequently, we are able to convert many quantized feedback design problems to well-known robust control problems with sector bound uncertainties. In particular, we derive the coarsest quantization densities for stabilization for multiple-input-multiple-output systems in both state feedback and output feedback cases; and we also derive conditions for quantized feedback control for quadratic cost and H/sub /spl infin// performances.

The sector bound approach to quantized feedback control | NOVA. The University of Newcastle's Digital Repository

This work presents a general framework for nonlinear systems subject to disturbances using disturbance observer based control (DOBC) techniques. A two-stage design procedure to improve disturbance attenuation ability of current linear/nonlinear controllers is proposed where the disturbance observer design is separated from the controller design. To facilitate this concept, a nonlinear disturbance observer is developed for disturbances generated by an exogenous system, and global exponential stability is established under certain condition. Furthermore, semiglobal stability condition of the composite controller consisting of a nonlinear controller and the nonlinear disturbance observer is established. The developed method is illustrated by the application to control of a two-link robotic manipulator.

/pdf/disturbance-observer-based-control-for-nonlinear-systems-5gmmz4z7cy.pdf

Disturbance observer based control for nonlinear systems

Stability and L2-gain analysis for switched delay systems: A delay-dependent method

In this paper, a robust nonlinear control design for ionic polymer metal composite (IPMC) with uncertainties is proposed by using artificial bee colony based-operator approach. In detail, first, for a nonlinear IPMC dynamic model with uncertainties, a robust control system based on operator based robust right coprime factorization (RRCF) approach is presented. Second, considering the unknown uncertain plant that generates limitations in obtaining so-called universal condition, a proportional integral (PI) controller is designed to realize tracking control for the proposed robust stable system. Moreover, an artificial bee colony (ABC) algorithm is used to obtain on line the control parameters (K p , K i ) of PI controller. Finally, the effectiveness of the proposed control system is confirmed by simulation results.

Robust nonlinear control design for an IPMC by using ABC-based operator approach

This paper presents a robust observer for third order minimum-phase dynamical systems with matched disturbances. By using implicit observer techniques and VSS theory, the robust observer is constructed for systems with arbitrarily relative degrees. The disturbance is also estimated by VSS theory. The estimated state and the disturbance are applied in a controller to place a desired pole and to cancel the disturbance of the closed-loop systems. Finally, examples and simulation results are presented to show the effectiveness of the algorithms.

Design of a robust observer and its application for third order systems with disturbances

This paper dicusses the output tracking control for a continuous-time linear plant containing uncertain hysteresis nonlinearities in actuator and sensor devices simultaneously, where the hysteresis is described by Prandtl-Ishlinskii model. A new adaptive control scheme is developed to compensate the plant, the actuator and the sensor uncertainties and to generate an adaptive estimate of the plant output. The proposed control law ensures the uniform boundedness of all signals in the closed-loop system. The tracking error between the estimated plant output and the desired output is guaranteed to converge to zero asymptotically.

/pdf/adaptive-control-for-continuous-time-systems-in-the-presence-g21ltjaeev.pdf

Adaptive control for continuous-time systems in the presence of actuator and sensor hysteresis

The print version of the above named paper did not reflect the correct Digital Object Identifier. The correct Digital Object Identifier is 10.1109/TIE.2008.926768.

Errata Erratum to "Adaptive Sliding-Mode Position Control for Piezo-Actuated Stage"

We consider the problem of estimating the position of an object moving in the space by observing its image with the aid of a CCD camera. The problem can be converted into the observation of a dynamical system with nonlinearities. A new method is proposed to identify the obtained dynamical system. The attraction of the new method is that the algorithm is very simple and easy to be implemented, and it is robust to measurement noises. Further, minor a priori knowledge of the system is required in the new formulation. Simulation results show the superiority of the new method to the traditional ones.

Xinkai Chen

Papers

Robust nonlinear control design for an IPMC by using ABC-based operator approach

Design of a robust observer and its application for third order systems with disturbances

Adaptive control for continuous-time systems in the presence of actuator and sensor hysteresis

Errata Erratum to "Adaptive Sliding-Mode Position Control for Piezo-Actuated Stage"

Observation for the perspective system