OVERVIEW Overview Introduction Motivations      High-Gain Control       Integral Control      Disturbance Observer-Based Control Basic Framework       Frequency Domain Formulation       Time Domain Formulation Early History      An Overview on Disturbance Estimation Approaches           Linear Disturbance Observer            Nonlinear Disturbance Observer      An Overview of Disturbance Estimation-Based Control Approaches           Robustness Performance and Stability           Composite Hierarchical Anti-DisturbanceControl            Compensation of Mismatched Disturbances DISTURBANCE ESTIMATION DESIGN Linear Disturbance Estimator Introduction Frequency Domain Disturbance Observer      Minimum-Phase Case       Nonminimum Phase Case Time Domain Disturbance Observer Extended State Observer Summary Basic Nonfinear Disturbance Observer Introduction Nonlinear Disturbance Observer for Constant Disturbances        A Basic Formulation       An Enhanced Formulation Nonlinear Disturbance Observer for General Exogenous Disturbances       A Basic Formulation       An Enhanced Formulation Summary Advanced Nonfinear Disturbance Observer Introduction High-Order Disturbance Observer      Constant Disturbance Case       Ramp Disturbance Case       High-Order Disturbance Case Extended High-Gain State Observer Finite-Time Disturbance Observer Summary DISTURBANCE OBSERVER-BASED CONTROL DESIGN Disturbance Observer-Based Control for Nonfinear Systems Introduction A General Design Framework Nonlinear Disturbance Observer-Based Control (NDOBC)       Nonlinear Disturbance Observer       Composite Controller Design Example Study Summary Generalized Extended State-Observer-Based Control for Systems with Mismatched Uncertainties Introduction Generalized Extended-State Observer-Based Control (GESOBC)           Composite Control Design      Stability and Disturbance Rejection Analysis            Case of Measurable States            Case of Unmeasurable States Simulation Example Further Discussions      Extension to MIMO System           Solvability of the Disturbance Compensation Gain           Controllable Condition       Parameter Design for GESOBC Summary Nonfinear Disturbance Observer-Based Control for Systems with Mismatched Uncertainties Introduction Problem Formulation Novel Nonlinear Disturbance Observer-Based Control       Controller Design      Stability Analysis      Disturbance Attenuation Analysis Application to A Nonlinear Missile       Longitudinal Dynamics of A Missile System      Nonlinear Dynamic Inversion Control       Nonlinear Disturbance Observer-Based Robust Control       Simulation Studies           External Disturbance Rejection Ability            Robustness Against Model Uncertainties Summary Nonfinear Disturbance Observer-Based Control for Systems with Arbitrary Disturbance Relative Degrees Introduction Problem Formulation NDOBC for SISO Nonlinear System with Arbitrary DRD      Control Law Design       Stability Analysis NDOBC for MIMO Nonlinear Systems with Arbitrary DRDs      Control Law Design       Stability Analysis An Illustrative Example Summary Linear/Nonfinear Disturbance Observer-Based Sliding Mode Control for Systems with Mismatched Uncertainties Introduction Linear Disturbance Observer-Based Sliding-Mode Control      Problems of the Existing SMC Methods      Novel SMC Method Based on a Disturbance Observer            Control Design           Stability Analysis      An Illustrative Example            Nominal Performance Recovery            Chattering Reduction Nonlinear Disturbance Observer-Based Nonsingular Terminal Sliding-Mode Control      Problem of the Existing NTSMC Methods       Novel NTSMC Method Based on a Finite-Time Disturbance Observer            Finite-Time Disturbance Observer            Control Design and Stability Analysis      An Illustrative Example Summary APPLICATION TO PROCESS CONTROL SYSTEMS Application to Process Control Systems Introduction System Modeling of Level Tank Disturbance Rejection Control Design and Implementation       Model Predictive Control       Disturbance Observer-Enhanced Model Predictive Control      Control Implementation Simulation and Experimental Studies      Simulation Results and Analysis      Experimental Results and Analysis       Summary Disturbance Rejection for Ball Mill Grinding Circuits Introduction Process Description       Process Background      Description of Grinding Circuit Control Scheme       Multivariable MPC Algorithm       Disturbance Observer for Process with Time Delays      DOB-MPC Scheme for Ball Mill Grinding Circuits Performance Analysis and Comparisons       Disturbance Rejection in Nominal Case       Disturbance Rejection in Model Mismatch Case Summary APPLICATION TO MECHATRONIC SYSTEMS Disturbance Rejection for Magnetic Leviation Suspension System Introduction Problem Formulation       Nonlinear MAGLEV Suspension Dynamics      Model Linearization       Problem Formulation DOBC Design Simulations and Analysis       External Disturbance Rejection Performance      Robustness Against Load Variation Summary Disturbance Rejection for Permanent Magnet Synchronous Motors Introduction Problem Description Control Strategy      The Principle of ESO-Based Control Method       Speed Controller Design      Current Controller Design Simulation and Experimental Results       Simulation Results      Experimental Results Summary APPLICATION TO FLIGHT CONTROL SYSTEMS Disturbance Rejection for Small-Scale Helicopters Introduction Helicopter Modeling Explicit Nonlinear MPC With Disturbances      Output Approximation      Explicit Nonlinear MPC Solution Disturbance Observer-Based Control       Disturbance Observer       Composite Controller Stability Analysis Simulation and Experiment Summary Disturbance Rejection for Bank-to-Turn Missiles Introduction Pitch/Yaw Dynamic Models of BTT Missiles Disturbance Observers Disturbance Observer-Based Robust Control       Feedback Control Design       Stability Analysis of Closed-Loop System       Design of Disturbance Compensation Gain Simulation Studies       External Disturbance Rejection Performance      Robustness Against Model Uncertainties Summary Disturban.