Adaptive Active Disturbance Rejection Control Research Articles

Adaptive Active Disturbance Rejection Control for DC–DC Converter With Time-Varying Disturbance

Adaptive Active Disturbance Rejection Control for DC–DC Converter With Time-Varying Disturbance

Event-based adaptive active disturbance rejection control for nonlinear large-scale systems with input delay

This paper explores the active disturbance rejection control (ADRC) issue for interconnected large-scale systems with unmeasured states, input delay and a total disturbance composed of unknown constrained external disturbances. An enhanced extended state observer is built via fuzzy logic systems to identify system uncertainties and states and keep restraining the total disturbance of uncertain systems. When the triggering condition is met, the tracking differentiator component of the ADRC is able to reduce the communication overhead by successfully applying the backstepping control approach and the dynamic event-triggered mechanism. Meanwhile, the integral compensation method eliminates the negative effect cased by the input delay. Furthermore, the developed decentralised fuzzy control scheme can ensure that all signals in the closed-loop systems are semiglobally uniformly ultimately bounded and Zeno behaviour does not occurs. Finally, an example is used to depict the validity of the control approach.

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.

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.

Adaptive Active Disturbance Rejection Control of an Actuated Ankle Foot Orthosis for Ankle Movement Assistance

Adaptive Active Disturbance Rejection Control of an Actuated Ankle Foot Orthosis for Ankle Movement Assistance

Input channel gain adaptive active disturbance rejection control based on robust adaptive finite‐time parameter estimation

AbstractThis paper presents a novel input channel gain adaptive active disturbance rejection control (ICGA‐ADRC) framework for the nonlinear control system with large load variation. This paper first introduces the design of ICGA‐ADRC and proves its stability through the rigorous Lyapunov approach. Subsequently, the proposed controller is simulated by subjecting it to a nonlinear mass‐spring‐damping system characterized by significant load variations. Furthermore, the position‐tracking performance of the controller is tested experimentally by using a motor‐driven pendulum system with various loads. Finally, the results of both simulations and experiments show that the ICGA‐ADRC is capable of compensating for system model uncertainty and external perturbation while accurately estimating the system input channel gain in real‐time. The innovation of this paper is that the robustness of active disturbance rejection control (ADRC) to the system load variation is significantly strengthened by integrating robust adaptive finite‐time parameter estimation method into the conventional ADRC control architecture.

Dynamic Surface-Based Adaptive Active Disturbance Rejection Control of Electrohydrostatic Actuators

The control accuracy and stability of the electrohydrostatic actuator (EHA) are directly impacted by parameter uncertainty, disturbance uncertainty, and non-matching disturbance, which negatively impacts aircraft rudder maneuvering performance and even results in rudder chatter. A dynamic surface-based adaptive active disturbance rejection control (DSAADRC) is proposed as a solution for these issues. It does this by developing a novel parametric adaptive law driven by the combination of tracking error, parameter estimation error, and state estimation error to estimate the unknown parameters, using three low-order ESOs to estimate and compensate the uncertain disturbances online, and employing a dynamic surface method to obtain the differential values of virtual control signals in the backstepping method to deal with non-matching disturbances. In this research, a Lyapunov stability analysis demonstrates that the method can achieve the position tracking accuracy of the EHA under time-varying external disturbances after first establishing an EHA dynamics model with nonlinearity and uncertainty, followed by the design of an adaptive active disturbance rejection control method based on dynamic surfaces for the uncertainties and perturbations. In contrast to control strategies like Robust Control (RC) and Adaptive Robust Control (ARC), simulation and experiment comparison shows that the method has stronger anti-disturbance under time-varying external disturbances.

Adaptive Active Disturbance Rejection Control for Path Tracking of Intelligent Vehicle

The path tracking controller often cannot maintain the lateral stability of vehicles on large curvy roads with low adhesion road, which is easy to cause vehicle instability. In this paper, an adaptive active disturbance rejection control (ADRC) is designed to generate a front wheel angle and an additional yaw moment at the same time to guarantee the vehicle tracking accuracy and vehicle stability at the same time. The vehicle two‐degree‐of‐freedom reference model and the path tracking error model are built to derive the error dynamics state equation. The multiinput multioutput ADRC decoupling control is studied. The BP neural network is designed to online adjust the four output parameters that are difficult to be determined in the nonlinear state feedback to form an adaptive ADRC. The yaw moment distribution scheme is studied next. By the joint simulation and hardware‐in‐the‐loop experiment, the results show that the proposed adaptive ADRC can obtain good vehicle tracking accuracy and vehicle stability at the same time not only on both high and low adhesion roads but on the road with large curvatures.

An Adaptive Active Disturbance Rejection Control Strategy for Speed-Sensorless Induction Motor Drives

Speed-sensorless control of induction motor drives based on the extended state observer (ESO) attracts much popularity due to its key characteristics, e.g., satisfactory estimation performance, and high robustness against disturbances. However, the conventional ESO generally uses fixed high gains to achieve fast convergence. This may bring about the concern of noise sensitivity. Moreover, a proportional-integral (PI)-type speed controller is mostly adopted in speed-sensorless control of induction motor drives, which may cause unsatisfactory system dynamics. To address these, an adaptive active disturbance rejection control (ADRC) strategy is proposed for speed-sensorless induction motor drives in this article. In this scheme, a third-order adaptive ESO (AESO) is first used to estimate the speed, the phase, and the overall disturbance. Then, a speed controller based on the state error feedback control rate (SEFCR) is designed to improve system dynamics. In practice, disturbances like dc offsets may further challenge estimation performance, and hence, a closed-loop flux observer (CLFO) is employed to deal with this issue. Additionally, a parameter sensitivity analysis of the CLFO is also provided to evaluate the performance of the proposed scheme. Finally, extensive experimental tests have been carried out to validate the effectiveness of the proposed.

Self-tuning adaptive active disturbance rejection pitch control of a manta-ray-like underwater glider

In this paper, a self-tuning adaptive active disturbance rejection control (ADRC) algorithm for the pitch angle control of a new manta-ray-like underwater glider—”NPManta II” is proposed. First, a new dynamic model of NPManta II is established, which quantifies the influence of installation error, bladder volume change and position change of the moving internal mass. Second, a linear extended state observer with parameter self-tuning based on the least mean square algorithm is designed. Third, a control-switching strategy is applied during posture transition to avoid inaccurate compensation of the control input. Finally, simulations and sea trial of the proposed adaptive ADRC controller and proportional integral differential controller are presented. The results indicate that the parameter converges quickly. The adaptive ADRC controller can effectively compensate for the control input, and move the internal mass to the optimal equilibrium position quickly and accurately, thus avoiding unnecessary movements to save energy.

Robust adaptive active disturbance rejection control of an electric furnace using additional continuous sliding mode component

The temperature control process of electric heating furnace (EHF) systems is a quite difficult and changeable task owing to non-linearity, time delay, time-varying parameters, and the harsh environment of the furnace. In this paper, a robust temperature control scheme for an EHF system is developed using an adaptive active disturbance rejection control (AADRC) technique with a continuous sliding-mode based component. First, a comprehensive dynamic model is established by using convection laws, in which the EHF systems can be characterized as an uncertain second order system. Second, an adaptive extended state observer (AESO) is utilized to estimate the states of the EHF system and total disturbances, in which the observer gains are updated online by a non-linear observer bandwidth, that is as a function of the observation errors. Moreover, with the help of disturbance estimation, a novel sliding manifold is constructed with parameters adaptively adjusted by a dynamic nonlinear bandwidth function to reduce the impact of high gain problems, especially noise-sensitivity. A continuous sliding-mode (CSM) based component is also designed to handle disturbance estimation errors. Third, the stability of the closed loop system, including the proposed controller and estimator, is mathematically proved using the Lyapunov theorem. Finally, the comparative simulation results show that the proposed method has superior robustness and temperature tracking performance.

Adaptive Active Disturbance Rejection Control for Rendezvous of a Swarm of Drones

This paper addresses the time-varying rendezvous problem of a swarm of drones with the leader-follower consensus hierarchy. Each drone in the swarm is under the influence of external disturbances in the form of wind gusts. To control the swarm of perturbed drones, this paper proposes a fully distributed adaptive leader-following time-varying disturbance rejection pinning control for the rendezvous of drones using the framework of the extended state observer that depends on the state estimates of the neighboring agents rather than the actual states. The communication topology within the swarm is modelled using algebraic graph theory. Unlike most of the literature in which the leader agent act as a virtual reference generator, an active leader agent with non-zero control input is considered. The states of the leader drone are only available to a subset of the graph. The communication topology between leader-follower is directed while that between follower-follower is undirected. Based on the relative output information between the neighboring drones, the extended state observer estimates the local states and disturbances of each drone and the adaptive control actively compensates for the external disturbances simultaneously. Finally, it is shown analytically as well as in simulations that the time-varying rendezvous can be achieved by the proposed algorithm effectively.

Adaptive Active Disturbance Rejection Control of Solar Tracking Systems with Partially Known Model

In this article, the trajectory tracking control of a solar tracking system is tackled by means of an adaptive active disturbance rejection control scheme. The state and disturbance estimation system is based on the combination of a time varying identification system and an adaptive observer. The stability and robustness of the controller is mathematically tested by means of the second method of Lyapunov, and its effectiveness is experimentally tested in a robotic test bed, achieving both lower energy consumption and better tracking results with respect to a PID-based controller.

Robust spacecraft rendezvous using a variable speed control moment gyro and thruster

Robust, co-ordinate free, thrust-vector tracking controls are designed for a single Variable Speed Control Moment Gyro (VSCMG). The proposed controls, based on an adaptive active disturbance rejection control and higher-order sliding mode control are presented and compared. These controls guarantee the closed-loop pointing error converges to and remain within a bounded region of the zero error even in the presence of the variable inertia induced by the VSCMG, thruster off-set and uncertain disturbance torques. Secondly, the pointing control law is developed to address the problem of spacecraft rendezvous using only a single thruster and a single VSCMG. Here a pointing guidance law is developed that weights the desired thrust of the rendezvous using a scaling function of the pointing error. This guidance law is shown to significantly improve the performance of the rendezvous maneuver with respect to a guidance law that does not utilize the scaling function. Simulations of a rendezvous maneuver with a 12 U CubeSat are undertaken to demonstrate the applicability of the developed control laws.

Current Driver Design for Electromagnetic Coil Using Adaptive Active Disturbance Rejection Control

An adaptive active disturbance rejection controller is used in the current driver design of the electromagnetic coil. Extended state observer of the 1st-order system is adopted for disturbance observation of ADRC. The supervised recursive least squares method is proposed for real-time parameters estimation, in which the excitation signal variance is used to trigger the parameter estimator. The experimental results demonstrate that ADRC combined with real-time parameter estimation simplifies the parameter tuning and improves the parameter adaptive ability.

An Adaptive ADRC Control for Parkinson’s Patients Using Machine Learning

Parkinson’s disease (PD) is one of the most common diseases that its main complications are hand and head tremors and inflexibility of muscles. One of the prevalent treatments that employ for reducing the symptoms of that is deep brain stimulation (DBS). In practice, a sensor is located in the patient’s finger for detecting and evaluating the tremor values in PD. Using an open-loop control structure for stimulating one area of basal ganglia (BG) is the common approach, but in this work, two areas of BG, named subthalamic nucleus (STN) and globus pallidus internal (GPi) are stimulated in a closed-loop manner separately for i) reducing the intensity of electric field and consequently disappearing the side effects of DBS ii) decreasing hand tremor. In particular, an adaptive Active Disturbance Rejection Control (ADRC) based on a deep deterministic policy gradient (DDPG) and a conventional feedback controller are presented for simultaneous stimulating STN and GPi, respectively. In this way, the control coefficients of the ADRC are considered as the control objective parameters that are designed by the actor and critic neural networks (NNs) of DDPG. The suggested scheme is applied to a BG system model which is frequently studied in the literature. The comprehensive simulation studies are accomplished to confirm the supremacy of the ADRC based DDPG scheme over the state-of-the-art strategies. Moreover, hardware-in-the-loop (HiL) simulations are performed to verify the efficiency of the proposed scheme from real-time perspective.

Adaptive active disturbance rejection control guaranteeing uniformly ultimate boundedness and simplicity

SummaryThe active disturbance rejection control (ADRC) scheme requires a high bandwidth in the extended state observer (ESO), causing heavy noise pollution in the control system. This article develops an effective and simple adaptive ADRC scheme to realize high performance control when ESO bandwidth is limited. The adaptative law is generated by the state tracking error such that all the feedback loops and feedforward channels are activated for active disturbance rejection. An “attached” and “quantified” adaptation is developed to guarantee the easy usage of the proposed scheme. The uniformly ultimate boundedness of all the signals in the closed‐loop system is proved in the sense of Lyapunov theory. Finally, two simulation examples are given to demonstrate the results.

A Novel Adaptive Active Disturbance Rejection Control Strategy to Improve the Stability and Robustness for a Wind Turbine Using a Doubly Fed Induction Generator

A novel and robust active disturbance rejection control (ADRC) strategy for variable speed wind turbine systems using a doubly fed induction generator (DFIG) is presented in this paper. The DFIG is directly connected to the main utility grid by stator, and its rotor is connected through a back-to-back three phase power converter (AC/DC/AC). Due to the acoustic nature of wind and to ensure capturing maximum energy, a control strategy to extract the available maximum power from the wind turbine by using a maximum power point tracking (MPPT) algorithm is presented. Moreover, a pitch actuator system is used to control the blades’ pitch angle of the wind turbine in order to not exceed the wind turbine rated power value in case of strong wind speeds. Furthermore, the rotor-side converter is used to control the active and reactive powers generated by the DFIG. However, the grid-side converter is used to control the currents injected into the utility grid as well as to regulate the DC-link voltage. This paper aims to study and develop two control strategies for wind turbine system control: classical control by proportional integral (PI) and the proposed linear active disturbance rejection control (LADRC). The main purpose here is to compare and evaluate the dynamical performances and sensitivity of these controllers to the DFIG parameter variation. Therefore, a series of simulations were carried out in the MATLAB/Simulink environment, and the obtained results have shown the effectiveness of the proposed strategy in terms of efficiency, rapidity, and robustness to internal and external disturbances.

Active Disturbance Rejection Voltage Control of a Floating Interleaved DC–DC Boost Converter With Switch Fault Consideration

To enhance the robustness and to deal with the switch fault uncertainty of a floating interleaved dc–dc boost converter (FIBC), an adaptive active disturbance rejection control (ADRC) is proposed in this paper. In particular, the controller parameter b 0 is adapted by obtaining approximately the system input control gain b in real time, based on the output duty cycles via digital filters. Compared with the conventional ADRC, the performance of the proposed controller is significantly improved, without the need of extra sensors. Moreover, the influence of the controller parameters on the system dynamical performance is analyzed theoretically, providing a practical guideline for controller tuning. The simulation and experimental results validate the effectiveness and the robustness of the proposed controller.

Q-Learning-based parameters adaptive algorithm for active disturbance rejection control and its application to ship course control

This paper concerns with the method of parameters tuning and the capability of active disturbance rejection control (ADRC) to the nonlinear plants. Firstly, an adaptive method of ADRC parameters based on Q-learning is proposed. Besides, to verify the effectiveness of the proposed parameter tuning strategy, the novel method is applied to the ship course control which has multifarious uncertainties due to the disturbance of wind, waves and currents. And then, for better control performance, when the training of Q value-table, the states stochastic initialize of each episode is not equiprobability, different state has different weights. The simulation results of both adaptive ADRC and linear active disturbance rejection control (LADRC) show that the proposed algorithm has the advantages of robustness and higher tracking precision.