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.

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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, the discrete-time fractional order integral sliding mode control design for linear uncertain systems is investigated. First, a new method is proposed to approximate the fractional order integral recursively. Then, the control design based on the proposed approximation is presented. Finally, the fuzzy tuning which adjusts the integral gain and the fractional order of the integral simultaneously is employed to improve the transient response of the control system. The effectiveness of the proposed strategy is verified by both simulations and experiments on a piezo-actuated positioning system.

Discrete-Time Fractional Order Integral Sliding Mode Control for Piezoelectric Actuators with Improved Performance Based on Fuzzy Tuning

http://www.nt.ntnu.no/users/skoge/prost/proceedings/ifac2008/data/papers/2925.pdf

Adaptive Control of Unknown Dynamic Hysteretic Systems

Most smart material based actuators (smart actuators) are known for their prominent characteristics of high resolution of positioning, high bandwidth, and the ease of integration in miniaturized systems. However, their applications are restricted by the inherent hysteresis nonlinearity. This paper presents a new modified Bouc-Wen (MBW) model which has a rate-dependent property. Then the proposed model is directly used in developing a robust adaptive control in order to eliminate the hysteresis effects. Finally, the efficacy of the designed control framework is verified via a real case where a giant magnetostrictive actuator (GMA) is used as the testbed.

An extended Bouc-Wen model based adaptive control for micro-positioning of smart actuators

Networks of coupled large scale oscillators have been studied in biology for a number of years. It has been recognized that transient in the nearest neighbor connected networks may take far too long to die out. In the model of mammalian rhythm, it is considered that a few long distance interconnections exist. Typically, these long distance interconnections are considered to occur in a random way. In this study, we discuss the synchronization problem for coupled oscillator networks which can model the mammalian rhythm. Finally, the distribution models for the random long distance connections are proposed and are demonstrated by simulation.

Modeling and analysis for oscillator networks

Presents a disturbance observer based on VSS theory for minimum-phase (with respect to the relation between the disturbance and output) dynamical systems with arbitrary relative degrees. The model uncertainties, the nonlinear parts of the system are merged into the disturbance term, and are regarded as a part of the disturbances. The upper bound of the disturbances is assumed to be known as a priori information. Simulation results are presented to show the robustness and effectiveness of the new disturbance observer. To show the practicality of the proposed design method, it is employed to control a linear motor.

Xinkai Chen

Papers

Discrete-Time Fractional Order Integral Sliding Mode Control for Piezoelectric Actuators with Improved Performance Based on Fuzzy Tuning

Adaptive Control of Unknown Dynamic Hysteretic Systems

An extended Bouc-Wen model based adaptive control for micro-positioning of smart actuators

Modeling and analysis for oscillator networks

A VSS disturbance observer and its applications