Disturbance Rejection Control Research Articles

Multisource disturbances rejection control for linear systems with unmeasured states under process and measurement disturbances

In this paper, a multisource disturbances attenuation and rejection control method is proposed for linear systems with unmeasured states under process and measurement disturbances. Since some internal states of control systems are hard to be measured via sensors in the realistic engineering process, a novel output feedback control scheme is proposed for designing the anti-disturbance controller by using measurement outputs, although these outputs mix with measurement disturbances. In addition, the dynamics of control system states also suffer from the influence of multiple process disturbances. To enhance the anti-disturbance ability of control systems, two kinds of disturbance observers are adopted to estimate process and measurement disturbances, respectively. And the anti-disturbance output feedback controller is constructed based on the process disturbance observer, state observer and H∞ control theory. In which the state observer is built via the measurement outputs and measurement disturbance observer. Then, the linear matrix inequality technology is used for analyzing the stability of closed-loop systems and decoupling the observers and the controller. Finally, the effectiveness of proposed control scheme is verified by using a numerical example.

High authenticity steering feel control strategy for Steer-by-Wire system based on terminal sliding mode rack force observer

This article proposes a high authenticity steering feel control strategy for Steer-by-Wire (SBW) system based on terminal sliding mode rack force observer, in response to the issue of how to design the steering feel of the SBW system to reflect road conditions. Firstly, a terminal sliding mode rack force observer is designed to achieve real-time and accurate estimation of steering system rack force. Then, based on the vehicle motion state, design the feedback characteristic curve of the rack force and the compensation torque of the handwheel to obtain the expected steering feel, and use the automatic disturbance rejection controller (ADRC) method to control the voltage of the handwheel motor. In simulation testing, a SBW open loop control system model is established to verify the performance of the designed rack force observer. The objective evaluation indicators are used to verify that the designed feedback method can intuitively adjust and meet the driver's steering feel needs, and the impact of various compensation torques on the evaluation indicators is analyzed. Finally, the results of actual vehicle experiments indicate that the designed method can provide suitable steering feel, verifying the feasibility of the design technology.

Feedback control of the COVID-19 outbreak based on active disturbance rejection control

The outbreak of COVID-19 causes a serious threat to human health and life around the world and puts enormous pressure on the healthcare system. The lockdown policy has effectively reduced the number of cases and suppressed the spread of the COVID-19 epidemic, but it also requires high social and economic costs. In this paper, we aim to use feedback control to help decision-makers establish lockdown policies, which can effectively constrain the spread of the COVID-19 pandemic with minimal financial loss. The time-dependent susceptible-infected-removed (SIR) model is used for the dynamics of the COVID-19 pandemic. The feedback control is based on a modified nonlinear active disturbance rejection controller (ADRC) that includes modified nonlinear extended state and nonlinear state error feedback with parameters tuned by particle swarm optimization, and the performances are compared with a well-known proportional-–integral–-derivative (PID) controller. The final simulation results show that the modified nonlinear ADRC has better performances and is more robust against uncertainties in the parameters of the epidemiological model.

Coupled translation and attitude tracking control for multi-satellite electromagnetic formation flight based on dual quaternion

Electromagnetic formation flight technology utilizes electromagnetic force and torque between satellites to control satellites’ relative position and attitude without consuming propellant, thus having broad application prospects. However, the dynamics of electromagnetic formation flying are nonlinear and strongly coupled, posing challenges to the 6-DOF control of electromagnetic formation and the magnetic dipole allocation of satellites. The frequency division multiplexing method can approximate decoupling formation dynamics by loading multi-frequency AC carriers onto satellite magnetic dipoles and is likely to achieve more control functions. A design method for AC carriers based on frequency division multiplexing is proposed to decouple formation dynamics while controlling electromagnetic force and torque. This paper further provides an analytical solution for the magnetic dipoles of the electromagnetic force/torque equations. In addition, in response to external disturbances, model uncertainty, and the inability to obtain relative velocity and angular velocity information of the formation system, this paper establishes a 6-DOF coupling model based on dual quaternion and implements tracking control using the active disturbance rejection control method. Based on the internal force characteristics of the electromagnetic formation, an expression for the equilibrium distribution of reaction wheel torque is derived to avoid some reaction wheels’ rapid accumulation of angular momentum. Numerical simulation results show the effectiveness of the proposed control method.

Adaptive Active Disturbance Rejection Control for Vehicle Steer-by-Wire under Communication Time Delays

In this paper, an adaptive active disturbance rejection control is newly designed for precise angular steering position tracking of the uncertain and nonlinear SBW system with time delay communications. The proposed adaptive active disturbance rejection control comprises the following two elements: (1) An adaptive extended state observer and (2) an adaptive state error feedback controller. The adaptive extended state observer with adaptive gains is employed for estimating the unmeasured velocity, acceleration, and compound disturbance which consists of system parameter uncertainties, nonlinearities, exterior disturbances, and time delay in which the observer gains are dynamically adjusted based on the estimation error to enhance estimation performances. Based on the accurate estimations of the adaptive extended state observer, the proposed adaptive full state error feedback controller is equipped with variable gains driven by the tracking error to develop control precision. The integration of the advantages of the adaptive extended state observer and the adaptive full state error feedback controller can improve the dynamic transient and static steady-state effectiveness, respectively. To assess the superior performance of the proposed adaptive active disturbance rejection control, a comparative analysis is conducted between the proposed control scheme and the classical active disturbance rejection control in two different cases. It is worth noting that the active disturbance rejection control serves as a benchmark for evaluating the performance of the proposed control approach. The results from the comparison studies executing two simulated cases validate the superiority of the suggested control, in which estimation, tracking response rate, and steering angle precision are greatly improved by the scheme proposed in this article.

Improved nonlinear active disturbance rejection control for a continuous-wave pulse generator with cascaded extended state observer

The generator rotor is crucial for the high-rate and reliable continuous-wave mud pulse transmission system. However, its dynamic responses are constrained by resistant load shocks and harsh operating environments. This study proposes an enhanced nonlinear active disturbance rejection control (EADRC) that integrates cascaded extended state observer (CESO) and enhanced nonlinear state error feedback (NLSEF) to address the abovementioned issues. The rotor motion model considering hydraulic torque is analyzed to characterize external load shocks, and an optimized nonlinear function, fal(·), is designed to improve slow convergence speed in high-error states. CESO is constructed to achieve timely and accurate disturbance estimations, while enhanced NLSEF is established to combine current and future system information for efficient feedback. Moreover, estimation capability and stability are theoretically proven based on the Lyapunov function. Simulations and experiments show that the proposed EADRC exhibits rapid response, high accuracy, and strong robustness in rotor speed control.

Linear active disturbance rejection control algorithm for active vibration control of piezo-actuated beams: Theoretical and experimental studies

The active vibration control (AVC) of lightweight thin-walled structures on spacecraft has been a proven solution for vibration suppression. In this study, a linear active disturbance rejection control (LADRC) algorithm is presented for vibration suppression of piezo-actuated beams. Firstly, the governing equation of a piezo-actuated beam is obtained by using the Euler–Bernoulli beam theory and the Lagrange equation. The LADRC algorithm is designed for the piezo-actuated beam based on the governing equation. Then, the accuracy of the piezo-actuated beam model is confirmed by comparison with ANSYS and experiments. Finally, numerical simulations and experiments are carried out on the active vibration suppression of the piezo-actuated beam under the fixed harmonic excitation, variable harmonic excitation, and fixed harmonic excitation with measuring noise, respectively. The results show that the LADRC algorithm has an excellent control effect on structural vibration suppression, strong adaptability to various external excitations, and anti-noise ability.

Harmonic suppression of active disturbance rejection control for virtual synchronous generators

SummaryVirtual synchronous generators (VSGs) are comprised of an outer power loop and inner cascaded control loops. The dynamic performance of the output interface is severely degraded when microgrid loads exhibit variability and nonlinearity. Therefore, robustness against load disturbances must be possessed by any voltage control scheme. In this paper, a proportional resonance‐linear active disturbance rejection control (PR‐LADRC) scheme based on an improved linear extended state observer (ILESO) is proposed for VSG voltage control. In comparison with the traditional linear extended state observer (LESO), the differential state variable of the output voltage is utilized to increase the observation bandwidth; consequently, the proposed ILESO can effectively overcome the disadvantage of phase lag when tracking disturbances. Additionally, a proportional resonance controller is incorporated into the LESO feedforward channel to suppress voltage harmonics. The proposed scheme enhances the disturbance observation bandwidth compared to traditional strategies, resulting in a substantial improvement in both the disturbance observation capability of LADRC and the harmonic suppression ability of the VSG system. Theoretical analysis and simulations are conducted to validate the effectiveness of the proposed PR‐LADRC approach.

Fast DC-link voltage control based on power flow management using linear ADRC combined with hybrid salp particle swarm algorithm for PV/wind energy conversion system

Hybrid Energy Systems (HESs) are offering several advantages over conventional generation systems because of the rising need for Renewable Energy Resources (RERs) and its high capability and flexibility of achieving the desired performance for both urban and rural areas. The main goals of HESs are to improve the system performance by increasing its flexibility, reliability and reducing generation instability. In the current work, a hybrid Photovoltaic/Wind Energy Conversion System (PV/WECS) is proposed to supply and support the utility grid. The generated power from the system is greatly responding to the change in both the wind speed and PV irradiance level, and as a result impacting the DC-Bus voltage of the system converters. Therefore, precise, fast and optimum controllers are required for the PV/WECS system to ensure the extraction and generation of stable maximum power during weather variations along with maintaining the DC-Link voltage at the desired value. Further, this study proposes a novel Linear Active Disturbance Rejection Control (LADRC) combined with a hybrid Salp Particle Swarm Algorithm (SPSA) to a grid-connected PV/WECS for extracting the Global Maximum Power (GMP), regulating the DC-Link voltage, and enhancing the active and reactive powers control. The capability of the proposed SPSA-LADRC based-MPPT approach is examined according to the tracking time, accuracy and response to internal and external disturbances and then comparing its performance with other techniques such as SPSA-SMC, SPSA-PID and SPSA-PI controllers respectively. The findings revealed that the LADRC can track and keep the DC-Link voltage as the desired reference value,1500 V, respond much faster than the PI, SMC, and PID controllers as well as keep the THD of the injected current into the grid at a low level of 2.25%. Finally, the performance of the proposed system is experimentally verified using Hardware-In-Loop (HIL). The obtained findings verify the capability and accuracy of the system and its great potential in the management of HESs.

Autonomous Landing of Quadrotor Unmanned Aerial Vehicles Based on Multi-Level Marker and Linear Active Disturbance Reject Control.

Landing on unmanned surface vehicles (USV) autonomously is a critical task for unmanned aerial vehicles (UAV) due to complex environments. To solve this problem, an autonomous landing method is proposed based on a multi-level marker and linear active disturbance rejection control (LADRC) in this study. A specially designed landing board is placed on the USV, and ArUco codes with different scales are employed. Then, the landing marker is captured and processed by a camera mounted below the UAV body. Using the efficient perspective-n-point method, the position and attitude of the UAV are estimated and further fused by the Kalman filter, which improves the estimation accuracy and stability. On this basis, LADRC is used for UAV landing control, in which an extended state observer with adjustable bandwidth is employed to evaluate disturbance and proportional-derivative control is adopted to eliminate control error. The results of simulations and experiments demonstrate the feasibility and effectiveness of the proposed method, which provides an effective solution for the autonomous recovery of unmanned systems.

Communication-Free Pulsed Power Distribution and Tracking Method for Hybrid Energy Storage System Based on Active Disturbance Rejection Control

Communication-Free Pulsed Power Distribution and Tracking Method for Hybrid Energy Storage System Based on Active Disturbance Rejection Control

Current Loop Disturbance Suppression for Dual Three Phase Permanent Magnet Synchronous Generators Based on Modified Linear Active Disturbance Rejection Control

Current Loop Disturbance Suppression for Dual Three Phase Permanent Magnet Synchronous Generators Based on Modified Linear Active Disturbance Rejection Control

Super-Twisting Extended State Observer-Based Quasi-Proportional-Resonant Controller for Permanent Magnet Synchronous Motor Drive System

For the purpose of realizing permanent magnet synchronous motor (PMSM) systems with strong robustness and smooth speed, the quasi-proportional-resonant (QPR) controller is combined with super-twisting extended state observer (STESO) in this paper. Although traditional active disturbance rejection control scheme generally selects a sufficiently large bandwidth of linear extended state observer (LESO) to enhance the time-varying disturbance rejection capacity, the bandwidth of LESO is limited by system stiffness. To solve this tough issue, the STESO using generalized super-twisting technique is developed to optimize the stability and anti-disturbance capacity of motor drive system. In addition, the QPR controller is combined with the proposed STESO to suppress the motor speed fluctuation. Experimental results show that the proposed STESO-based QPR control algorithm has satisfactory characteristics.

Enhanced Active Disturbance Rejection Control With Measurement Noise Suppression for PMSM Drives via Augmented Nonlinear Extended State Observer

Enhanced Active Disturbance Rejection Control With Measurement Noise Suppression for PMSM Drives via Augmented Nonlinear Extended State Observer

Switching Longitudinal and Lateral Semi-decoupled Active Disturbance Rejection Control for Unmanned Ground Vehicles

In this paper, a switching longitudinal and lateral semi-decoupled active disturbance rejection control (ADRC) strategy is proposed for motion control of unmanned ground vehicles (UGVs). To characterize the coupling property between longitudinal and lateral dynamics, a switching longitudinal and lateral semi-coupled model is first developed. By utilizing the switching method, a so-called “two-stage ADRC” strategy is presented. It has two forms before and after the transition instant such that the boundedness premise for the derivative of the total disturbance can be removed. With the designed two-stage ADRC, a longitudinal and lateral semi-decoupled controller is then suggested to solve the motion control problem of UGVs. Finally, both stability analysis and comparison results are given to demonstrate the effectiveness and robustness of the proposed control strategy.

An Improved Strategy of Grid-Forming DFIG Based on Disturbance Rejection Stator Flux Control

Grid-forming (GFM) control are promising for doubly fed induction generator-based wind turbines (DFIG -Based WTs) due to its grid-support ability and stable operation when connected to weak grid. However, GFM-DFIG might suffer from instability under symmetrical grid fault, if its electromagnetic and synchronous dynamics are poor. Therefore, an improved strategy of GFM-DFIG based on disturbance rejection stator flux control (DRSFC) is proposed in this paper. The DRSFC consists of a PI-based rotor-current loop and an active disturbance rejection control (ADRC)-based stator-flux outer loop, and both the better electromagnetic performance and the steady-state voltage source operation are achieved. Besides, impacts of DRSFC on GFM-DFIG are exposed via small-signal and large-signal analysis, and the potential inertia in the inner control loops is revealed. It is suggested that this potential inertia is reshaped by DRSFC, so the impact of inner control loop on the synchronization of GFM-DFIG can be quantitatively studied and controlled. On this basis, a pair of asymmetrical compensation are designed to improve its electromagnetic decay and synchronous dynamic. Finally, experiments are carried out to verify the effectiveness of proposed strategy.

Speed Control of IPMSM Based on Series Connection Leading Correction Linear Active Disturbance Rejection Controller

Speed Control of IPMSM Based on Series Connection Leading Correction Linear Active Disturbance Rejection Controller

Improved ADRC With a Cascade Extended State Observer Based on Quasi-Generalized Integrator for PMSM Current Disturbances Attenuation

Traditional active disturbance rejection control (ADRC) is not adequately capable to deal with current disturbances including periodic harmonics of permanent magnet synchronous motor (PMSM). Thus, an improved ADRC with a cascade extended state observer (CESO) based on quasi-generalized integrator (QGI) is proposed to attenuate the periodic and aperiodic disturbances in the current loop. In the proposed strategy, a CESO with two cascaded levels is designed to enhance the estimation accuracy of aperiodic disturbances and decrease the steady-state observation error of periodic harmonics. The QGI is embedded into the second cascade level of CESO to improve its estimation accuracy harmonic disturbances. With the periodic harmonics accurately estimated, the subsequent improved ADRC based on feedback control law can effectively enhance the rejection of such disturbances. The theoretical analysis is comprehensively conducted to investigate the disturbances estimation performance, stability, disturbances rejection capability and robustness, while the parameter tuning strategy is studied based on the control bandwidth. Finally, the effectiveness and superiority of the proposed scheme are verified on a PMSM bench through the experiments.

Active Disturbance Rejection Control of Bearingless Permanent Magnet Slice Motor Based on RPROP Neural Network Optimized by Improved Differential Evolution Algorithm

Active Disturbance Rejection Control of Bearingless Permanent Magnet Slice Motor Based on RPROP Neural Network Optimized by Improved Differential Evolution Algorithm

Adaptive Active Disturbance Rejection Control for Uncertain Current Ripples Suppression of PMSM Drives

Under complex working conditions, there are uncertain periodic and aperiodic disturbances in the curr- ent loop of permanent magnet synchronous motor (PMSM) drives. These uncertain disturbances can lead to uncertain current ripples, deteriorating the current loop performance. To deal with the problem, this paper proposes an adaptive active disturbance rejection control (ADRC) for the current loop to suppress the uncertain current ripples. In the ada- ptive ADRC, the extended state observer is optimized by the adaptive resonant controller so that it can estimate both the uncertain periodic and aperiodic disturbances. Thus, the adaptive ADRC can suppress both the uncertain periodic and aperiodic disturbances to attenuate the uncer- tain current ripples in the current loop, and it does not need the disturbance information. In addition, the stability of the observer in the adaptive ADRC is systematically analyzed by the singular perturbation theory and the averaging theorem. Finally, the effectiveness of the adaptive ADRC is validated on a 2.2-kW PMSM platform.