Disturbance Observer-based Control Research Articles

Disturbance Observer-Based Finite-Time Braking Control of Vehicular Platoons

Disturbance Observer-Based Finite-Time Braking Control of Vehicular Platoons

Deep-Coupled Sliding Mode Disturbance Observer-Based Composite Attitude Control for Flexible Communication Spacecrafts

Deep-Coupled Sliding Mode Disturbance Observer-Based Composite Attitude Control for Flexible Communication Spacecrafts

Asymmetric integral barrier function-based tracking control of constrained robots

<abstract><p>In this paper, a new-type time-varying asymmetric integral barrier function is designed to handle the state constraint of nonlinear systems. The barrier Lyapunov function is developed by building an integral upper limit function with respect to transformation errors over an open set to cope with the position constraint of the robotic system. We know that the symmetric time-invariant constraint is only a particular situation of the asymmetric time-variant constraint, and thus compared to existing methods, it is capable of handling more general and broad practical engineering issues. We show that under the integral barrier Lyapunov function combining a disturbance observer-based tracking controller, the position vector tracks a desired trajectory successfully, while the constraint boundary is never violated. It can certify the exponential asymptotic stability of the robotic tracking system by using the given inequality relationship on barrier function and Lyapunov analysis. Finally, the feasibility of the presented algorithm is indicated by completing the simulations.</p></abstract>

Disturbance Observer-Based Fixed-Time Event-Triggered Control for Networked Electro-Hydraulic Systems With Input Saturation

Disturbance Observer-Based Fixed-Time Event-Triggered Control for Networked Electro-Hydraulic Systems With Input Saturation

Adaptive Refined Disturbance Observer-Based Velocity-Tracking Control for Gimbal Servo System With Multiple Disturbances

Adaptive Refined Disturbance Observer-Based Velocity-Tracking Control for Gimbal Servo System With Multiple Disturbances

Disturbance Observer-Based Robust Current Control Scheme for Three-Phase Grid-Tied Inverters With LCL Filter Considering Unbalanced Grid Voltages

Disturbance Observer-Based Robust Current Control Scheme for Three-Phase Grid-Tied Inverters With LCL Filter Considering Unbalanced Grid Voltages

Disturbance Observer-based Finite-time Optimal Synchronization Control for Multi-motor Driving Servo Systems

Disturbance Observer-based Finite-time Optimal Synchronization Control for Multi-motor Driving Servo Systems

Augmented Disturbance Observer-Based Appointed-Time Tracking Control of UAVs Under Exogenous Disturbance

Augmented Disturbance Observer-Based Appointed-Time Tracking Control of UAVs Under Exogenous Disturbance

Fuzzy Disturbance Observer-based Fixed-time Attitude Control for Hypersonic Morphing Vehicles

Fuzzy Disturbance Observer-based Fixed-time Attitude Control for Hypersonic Morphing Vehicles

Disturbance Observer-Based Anti-windup Control for Path-Following of Underactuated AUVs via Singular Perturbations: Theory and Experiment

Disturbance Observer-Based Anti-windup Control for Path-Following of Underactuated AUVs via Singular Perturbations: Theory and Experiment

Fixed-Time Disturbance Observer-Based Terminal Sliding Mode Control for Manipulators With a Novel Reaching Law

Fixed-Time Disturbance Observer-Based Terminal Sliding Mode Control for Manipulators With a Novel Reaching Law

State and Disturbance Observer-Based Controller Design for Fully Actuated Systems

State and Disturbance Observer-Based Controller Design for Fully Actuated Systems

Disturbance-observer-based control for non-homogeneous semi-Markov jump systems with time-varying delays

This paper discusses the issue of disturbance-observer-based control (DOBC) for a kind of continuous-time non-homogeneous semi-Markov jump systems (SMJSs) with time-varying delays. Unlike the existing results, the system examined in this article is about non-homogeneous SMJSs, which indicates that its transition rates (TRs) is time-varying. The versions of TRs matrices are selected by a switching signal, which is independent of the semi-Markov process that decides on the system modes. The time-varying TRs are established to be of two situations: stochastic process and arbitrary switching, respectively. First, we construct a novel class of Lyapunov function that is related to both system mode and switching signal mode, thus it can make more use of information about the system and help reduce conservatism. Second, some conditions are given to guarantee the exponentially mean square stable of the SMJSs and H∞ output tracking performance index. Finally, two examples are provided to demonstrate the efficacy of research methods.

Robust Direct Power Flow Control of Voltage Source Converters

In this study, a disturbance observer-based power control system is developed for voltage source converters (VSC) to achieve smooth power delivery to the grid. Firstly, modeling of grid connected converter which is used for power delivery in terms of frequency and current dynamics is executed under consideration of modelling errors and uncertainties. This disturbance effects are mainly consist of frequency and amplitude variations, output impedance aging, large dc-link voltage ripple A second order nonlinear observer is integrated into the designed control to reject with model uncertainty and disturbances. Due to the objective of the proposed controller is power regulation, there is no need a voltage and current compensator. Comperative simulations are carried out to verify the robustness of the proposed controller. Also effectiveness of the proposed approach is tested under different grid scenarios (e.g., weak grid, dc-link variation, frequency deviation)

Experimental Verification of Disturbance Observer-Based Backstepping Control for DC–DC Boost Converter

Experimental Verification of Disturbance Observer-Based Backstepping Control for DC–DC Boost Converter

Active fault-tolerant control for the dual-valve hydraulic system with unknown dead-zone

This paper proposes a method for high-performance motion control of the dual-valve hydraulic system subject to parameter and model uncertainties, unknown proportional valve dead-zone, and servo valve fault. By constructing a detailed dual-valve fault system model (DFSM), a disturbance observer-based adaptive robust fault-tolerant controller is proposed via the backstepping method. This controller integrates a model-based fault detection algorithm for real-time fault monitoring and subsequent controller reconfiguration. Additionally, the DFSM-based adaptive robust control (ARC) technique is applied to handle the unknown dead-zone problem and other nonlinearities, ensuring precise control. Once the servo valve fault occurs, a nonlinear observer estimates the fault and collaborates with the ARC to establish a reconfigured controller, thereby maintaining motion control. The effectiveness of the proposed method has been experimentally verified.

High-order disturbance observer-based safe tracking control for a class of uncertain MIMO nonlinear systems with time-varying full state constraints

This paper investigates a high-order disturbance observer-based safe tracking control scheme for a class of uncertain multiple-input and multiple-output systems under time-varying full state constraints and disturbances. To achieve the safe tracking objective, a boundary protection algorithm is introduced to generate new safe desired signals which are within corresponding state constraints. An improved second-order dynamic surface control technology is developed to deal with the piecewise differentiability of safe desired signals and the phenomenon of repeatedly differentiation, simultaneously. To handle the negative effects of system uncertainties and obtain better estimation effect of high order time-varying disturbances, the radial basis function neural networks and high-order disturbance observer methods are developed. The safety and performance of the closed-loop nonlinear system under the proposed control scheme have been rigorous proved and discussed by Lyapunov stability analysis. Finally, a two-link manipulator model has been given as an example, and the numerical simulations are given to express the availability of the proposed controller.

Disturbance Observer-Based Event-Triggered Adaptive Command Filtered Backstepping Control for Fractional-Order Nonlinear Systems and Its Application

This paper considers the disturbance observer-based event-triggered adaptive fuzzy tracking control issue for a class of fractional-order nonlinear systems (FONSs) with quantized signals and unknown disturbances. To improve the disturbance rejection ability, a fractional-order nonlinear disturbance observer (FONDO) is designed to estimate the unknown composite disturbances. Furthermore, by combining an improved fractional-order command-filtered backstepping control technique and an event-triggered control mechanism, an event-triggered adaptive fuzzy quantized control scheme is established, which guarantees the desired tracking performance can be achieved even in the presence of network constraint. Finally, the validity and superiority of the theoretic results are verified by a fractional-order horizontal platform system.

Erratum: Global versus local Lyapunov approach used in disturbance observer-based wind turbine control

Erratum: Global versus local Lyapunov approach used in disturbance observer-based wind turbine control

Disturbance Observer-Based Safe Tracking Control for Unmanned Helicopters with Partial State Constraints and Disturbances

In this paper, a disturbance observer-based safe tracking control scheme is proposed for a medium-scale unmanned helicopter with rotor flapping dynamics in the presence of partial state constraints and unknown external disturbances. A safety protection algorithm is proposed to keep the constrained states within the given safe-set. A second-order disturbance observer technique is utilized to estimate the external disturbances. It is shown that the desired tracking performance of the controlled unmanned helicopter can be achieved with the application of the backstepping approach, dynamic surface control technique, and Lyapunov method. Finally, the availability of the proposed control scheme has been shown by simulation results.