Active Disturbance Rejection Control Technique Research Articles

Enhancement of virtual inertia via delay designed GADRC in hybrid microgrid with communication delay

The lowering of inertia in a hybrid microgrid caused by the incorporation of renewable sources of energy leads to an increased rate of change of frequency and frequency deviation in the system. Further, the varying load demand and the presence of communication delay adversely affect the frequency regulation. In view of this, in this paper, a modified virtual inertia control strategy is formulated and implemented through the energy storage device to enhance the overall inertia of the hybrid microgrid. Secondly, a delay-designed generalized active disturbance rejection control (DD-GADRC) technique is proposed for the secondary frequency control of the power system under varying communication delay and rapidly fluctuating load demand in the system. The effectiveness of the proposed control scheme is evaluated across multiple scenarios, including situations when there are continuous changes in solar or wind power generations. The robustness of the proposed technique is also evaluated under parametric variations and the presence of non-linearities in the system. Finally, the effectiveness of the proposed technique is analyzed and compared to various pre-existing control strategies in the literature related to the hybrid microgrid.

Active Disturbance Rejection Control for Distributed Energy Resources in Microgrids

Motivated by the significant efforts developed by researchers and engineers to improve the economic and technical performance of microgrids (MGs), this paper proposes an Active Disturbance Rejection Control (ADRC) for Distributed Energy Resources (DER) in microgrids. This approach is a nonlinear control that is based on a real-time compensation of different estimated disturbances. The DER operates along with the electrical grid to provide the load requirements. This load has a nonlinear and uncertain character, which presents a source of unmodeled dynamics and harmonic perturbations of the MG. The main objective of this paper is to ensure the stability and the continuity of service of the distributed generation resources by controlling the DC-AC converter. The ADRC as a robust control technique is characterized by its ability to compensate for the estimated total disturbances caused by the load variation and the external unmodeled perturbations to guarantee the high tracking performance of sinusoidal reference signals in the DER system. The ADRC technique is characterized by its nonlinear function, which provides a high robustness to the controlled system. However, in order to simplify the control structure by keeping its high reliability, this paper proposes to replace the nonlinear function with a simple error (termed linear ADRC), compares the impact of this modification on the system performances, and evaluates its operation in the presence of linear and nonlinear load variations. Simulation results are presented to demonstrate the efficiency of the proposed control approach for a three-phase DER.

Hybrid cyber-attack compensation of sustainable microgrid using active disturbance rejection control strategy

A modified active disturbance rejection control (ADRC) strategy for the frequency regulation of sustainable microgrid against hybrid cyber-attacks is proposed in this paper. The proposed technique mitigates the effect of attacks which in turn regulates the frequency of microgrid. The sustainable microgrid consists of solar and wind as renewable energy sources, energy storage systems (ESSs) like battery ESS and flywheel ESS, and controllable sources of energy like fuel cell and diesel generator. The cyber-attacks such as false data injection, denial-of-service and time delay attack are considered for designing the proposed ADRC technique. The robustness of the microgrid system with the proposed controller is investigated by varying generation and load, stochastic nature of attacks, parametric uncertainties and generation rate constraint and governor dead band nonlinearities. Further, the stability analysis of the microgrid with proposed ADRC is investigated under the aforementioned cyber-attacks using the small gain theorem.

Stability and energy-saving coordinated control strategy of six-wheel independent drive unmanned ground vehicle

During the operation of six-wheel independent drive unmanned ground vehicle (6WID UGV) in the field, the inconsistent tire contact characteristics and frequent steering maneuvers have led to increasingly prominent issues of tire excessive wear and lateral instability. Therefore, a coordinated hierarchical controller for 6WID UGV is proposed to ensure the stability of the steering process while reducing tire wear and motor energy consumption. First, a sliding mode controller (SMC) with an extended-state observer (ESO) is proposed for lateral stability control referencing the active disturbance rejection control (ADRC) technique, achieving fast response and robustness to uncertainty. Second, the lower controller constructs a Lagrangian function with tire slip energy loss and energy consumption as optimization objectives and allocates torque based on the Pareto optimal solution within the feasible domain given by the upper controller. Finally, the designed controller is tested under typical operating conditions. The results indicate that the designed coordinated controller has significant control performance and economic benefits in improving lateral stability and reducing energy loss. Compared with the torque distribution strategy based on tire vertical load, the tire slip energy is reduced by 44.8 % and 17.7 % in the process of traction/steering and braking/steering, respectively. In addition, the motor energy consumption and the friction braking energy loss are reduced by 12.1 % and 70.8 % respectively.

Low-voltage ride-through capability improvement of Type-3 wind turbine through active disturbance rejection feedback control-based dynamic voltage restorer

Abstract Disconnections due to voltage drops in the grid cannot be permitted if wind turbines (WTs) contribute significantly to electricity production, as this increases the risk of production loss and destabilizes the grid. To mitigate the negative effects of these occurrences, WTs must be able to ride through the low-voltage conditions and inject reactive current to provide dynamic voltage support. This paper investigates the low-voltage ride-through (LVRT) capability enhancement of a Type-3 WT utilizing a dynamic voltage restorer (DVR). During the grid voltage drop, the DVR quickly injects a compensating voltage to keep the stator voltage constant. This paper proposes an active disturbance rejection control (ADRC) scheme to control the rotor-side, grid-side and DVR-side converters in a wind–DVR integrated network. The performance of the Type-3 WT with DVR topology is evaluated under various test conditions using MATLAB®/Simulink®. These simulation results are also compared with the experimental results for the LVRT capability performed on a WT emulator equipped with a crowbar and direct current (DC) chopper. The simulation results demonstrate a favourable transient and steady-state response of the Type-3 wind turbine quantities defined by the LVRT codes, as well as improved reactive power support under balanced fault conditions. Under the most severe voltage drop of 95%, the stator currents, rotor currents and DC bus voltage are 1.25 pu, 1.40 pu and 1.09 UDC, respectively, conforming to the values of the LVRT codes. DVR controlled by the ADRC technique significantly increases the LVRT capabilities of a Type-3 doubly-fed induction generator-based WT under symmetrical voltage dip events. Although setting up ADRC controllers might be challenging, the proposed method has been shown to be extremely effective in reducing all kinds of internal and external disturbances.

Research on Active Disturbance Rejection Algorithm for Loading Control of 3-DOF Parallel Robot

A three-dimensional (3D) loading device based on a pneumatic 3-universal-prismatic-universal (UPU) parallel manipulator (three chains with UPU joint each) is designed to apply time-varying multi-dimensional loads to a target. First, according to the principle of vector superposition and Newton–Raphson method, the inverse and forward kinematics of the loading device are analyzed. Second, based on the screw theory, the static mapping between the dynamic platform and actuations is derived. Third, a second-order mathematical model is established for pneumatic 3-UPU parallel mechanism based on proportional flow valve and a metal seal pneumatic cylinder. A referential inaccurate model is provided for the control algorithm during modeling. Fourth, based on active disturbance rejection control (ADRC) technique, a 3D loading control algorithm is proposed and dynamic loading control is realized. Experimental results show that the ADRC algorithm has good robustness against disturbances, the steady-state control accuracy is less than 2 N, and the mean square error in dynamic tracking (sinusoidal tracking at 0.2 Hz) is less than 10.5 N.

Undulating Propulsion Underwater Robot Control Method Based on ADRC and Fuzzy Logic

The article is devoted to the development a closed-loop depth and course control algorithms for underwater robot with pair undulating fin. The controller was proposed based on the Active Disturbance Rejection Control (ADRC) technique and fuzzy logic. A brief review of the underwater robot with pair undulating fin (AUV) is carried out. The dynamic and kinematic robot model is given, and the robot model with the environment is presented in the Simscape-MATLAB library. To solve the problem of controlling course and depth of the robot, a method of Active Disturbance Rejection Control (ADRC) is proposed. This robust control method based on extension of the system model with an additional and fictitious state variable, representing everything that is not included in the mathematical description of the plant. This method allows to treat the considered system with a simpler model, since the negative effects of modeling uncertainty are compensated in real time. The advantage of the proposed method is that an exact analytical description of the system is not required, since it can be assumed that the unknown parts of the dynamics are internal noise in the installation. The fuzzy control method is used to build a non-linear relationship between controller outputs and fin parameters that determine the generated fin forces. The results of modeling of the problem of heading and depth control using a complete nonlinear dynamic model with six degrees of freedom are presented. The conducted studies confirm the operability, adequacy, and anti-disturbance ability of the ADRC controller.

A Novel Closed-Loop Structure for Drag-Free Control Systems with ESKF and LQR.

Space-borne gravitational wave detection satellite confronts many uncertain perturbations, such as solar pressure, dilute atmospheric drag, etc. To realize an ultra-static and ultra-stable inertial benchmark achieved by a test-mass (TM) being free to move inside a spacecraft (S/C), the drag-free control system of S/C requires super high steady-state accuracies and dynamic performances. The Active Disturbance Rejection Control (ADRC) technique has a certain capability in solving problems with common perturbations, while there is still room for optimization in dealing with the complicated drag-free control problem. When faced with complex noises, the steady-state accuracy of the traditional control method is not good enough and the convergence speed of regulating process is not fast enough. In this paper, the optimized Active Disturbance Rejection Control technique is applied. With the extended state Kalman filter (ESKF) estimating the states and disturbances in real time, a novel closed-loop control structure is designed by combining the linear quadratic regulator (LQR) and ESKF, which can satisfy the design targets competently. The comparative analysis and simulation results show that the LQR controller designed in this paper has a faster response and a higher accuracy compared with the traditional nonlinear state error feedback (NSEF), which uses a deformation of weighting components of classical PID. The new drag-free control structure proposed in the paper can be used in future gravitational wave detection satellites.

On stabilization of an axially moving string with a tip mass subject to an unbounded disturbance

This paper deals with the stabilization problem of an axially moving string with a tip mass attached at the free end and subject to an external disturbance. The disturbance here is not uniformly bounded, and it is assumed to be exponentially increasing. First, the tip mass equation is designed under a boundary controller. By using this equation, the active disturbance rejection control (ADRC) technique is applied to design a disturbance observer, and it is shown that the observer can be estimated exponentially. Then, the closed‐loop system is formulated and the well‐posedness of the model is proved in the framework of the semigroup theory. The stability of the closed‐loop system is then proved by means of the multiplier technique, where the energy system converges to equilibrium with an exponential manner. The efficiency of the obtained results is verified through numerical simulations.

Predictive Generalized Active Disturbance Rejection Control for Fractional Order Systems with Time Delay

Abstract In this paper, two different active disturbance rejection control techniques based on notion of Smith Predictor are proposed for control of fractional order stable systems with time delay. In the proposed Smith Predictor based Fractional order linearised active disturbance rejection control (SP-FO-LADRC) technique, fractional order dynamics are treated as a part of generalized disturbance and concept of Smith Predictor is used to obtain delay less output, which is fed to an extended state observer (ESO) and an integer order control strategy is developed. To further ameliorate control performance of this technique, complete plant information of commensurate fractional order system is used to formulate another new technique, namely Smith Predictor based fractional order generalized active disturbance rejection control (SP-FO-GADRC), which incorporates fractional ESO and leads to formulation of fractional order control law. An extensive simulation study and robustness analysis conducted on three different examples is testimony to efficacy of proposed techniques.

Research on flywheel energy storage control strategy based on active disturbance rejection controller

Based on nonlinear busbar voltage in flywheel energy storage systems and frequent discharge characteristics, in order to improve the dynamic control derived from the analysis of a permanent magnet synchronous motor and its inverter set up model of DC bus and the active disturbance rejection principle and use the active disturbance rejection control (ADRC) technique to design the DC bus voltage adaptive controller, the first- and second-order ADRC controllers are compared with the traditional PI controller in MATLAB. In this work, we demonstrate that the voltage controller designed with the first- and second-order ADRCs was superior to a traditional PI in terms of dynamic performance control.

Application of Active Disturbance Rejection in a Bearingless Machine with Split-Winding

In this paper it is proposed the displacement control of a bearingless induction machine (BIM) with split winding and optimized drive structure using Active Disturbance Rejection Control (ADRC). Considering that the BIM is a multivariable, nonlinear, and time-varying system with coupled variables, advanced control techniques can be useful in order to make the system operate efficiently and with good dynamic performance. The ADRC considers the total disturbance, composed of unmodeled dynamics, nonlinearities, uncertainties, and load variations, as an extended state and estimates it in real-time through a state observer. This increases the overall robustness of the control system to disturbances of different natures. The application of the ADRC technique on the radial position control of the BIM used in this work showed that a Linear version of ADRC is not able to compensate for radial load disturbances but this drawback can be solved by the use of a nonlinear observer in the ADRC structure. Besides that, both control versions of the ADRC were able to make stable the naturally unstable radial displacement of the machine’s rotor.

Prescribed-time zero-error active disturbance rejection control for uncertain wheeled mobile robots subject to skidding and slipping

This paper investigates the prescribed-time control problem for a class of wheeled mobile robot (WMR) subject to nonparametric skidding, slipping and input disturbance in an inner-outer loop framework. First, by backstepping approach, the virtual linear and angular velocities are acquired to follow the reference path to one special point. Then, different from the conventional ones for canonical integral cascade model, a novel prescribed-time extended state observer (PTESO) is designed for WMR such that the unknown skidding and slipping can be observed and compensated. By developing the active disturbance rejection control technique, the zero-error control is achieved for WMR in prescribed time instead of ultimately uniform boundedness. Moreover, the influence of the uncertainty is attenuated by the compensation scheme based on the PTESO estimation. Finally, some simulation results are presented to demonstrate the superiority and effectiveness of the developed method.

High-Performance Attitude Control Design of Supersonic Tailless Aircraft: A Cascaded Disturbance Rejection Approach

This paper focuses on the triaxial augmentation ability of the active disturbance rejection control (ADRC) technique on the tailless layout with a fully moving wing tip to achieve high control performance for the supersonic tailless aircraft. Firstly, the stability characteristics and controllability of the flying wing layout are analyzed to determine the coupling characteristics of this kind of aircraft. Secondly, an attitude controller is designed based on ADRC theory, and the linear ADRC frequency domain analysis method is introduced to analyze the influence of the bandwidth of linear extended stator on the control system. In addition, the tuning process of the attitude control law is given. Carrier dropping simulations of flight missions under nominal condition, model parameter perturbation, and wind disturbance are conducted. The results show that the designed controller can achieve full-speed domain triaxial augmentation of supersonic flying wing. This work has the potential to significantly boost the engineering acceptability and robustness of supersonic aircraft control design in real-world scenarios. The presented cascaded ADRC approach can significantly improve the performance and robustness of supersonic vehicles.

Research on active disturbance rejection control technique for underwater welding robot based on model compensation

PurposeAn active disturbance rejection controller (ADRC) based on model compensation is proposed in this paper. The method should first be taken a nominal model of the robot to compensate. Subsequently, the uncertain external disturbance is estimated and compensated is used an expansion state observer (ESO) in real time, which can reduce the estimating range of observation for ESO. The purpose of this paper is to suggest a novel method to improve the system tracking performance, as well as the dynamic and static performance index.Design/methodology/approachA welding robot is a complicated system with uncertainty, time-varying, strong coupling and a nonlinear system; it is more complex as if it is used in an underwater environment, and it is difficult to establish an accurate dynamic model for an underwater welding robot. Aiming at the tracking control of an underwater welding robot, it is difficult to achieve the control performance requirements by the conventional proportional integral derivative method to realize automatic tracking of the seam.FindingsThe simulation experiment is carried out by MATLAB/Simulink, and the application experiment is recorded. The experimental results show that the control method is correct and effective, and the system’s tracking performance is stable, and the robustness and tracking accuracy of the system are also improved.Originality/valueThe seam gets plumper and smoother, with better continuity and no undercut phenomenon.

Neural network–based active control of a rigid–flexible spacecraft with bounded input

This paper investigates the simultaneous control of a spacecraft with a rigid central hub and two flexible appendages. Taking into account the coupling between the vibration of flexible appendages and the motion of the hub, the rigid–flexible spacecraft subjected to external disturbance is modeled as a hybrid lumped–distributed parameter system. To attenuate the vibrations of the hub and flexible appendages and simultaneously track the given attitude angle, two boundary control laws are developed based on the original dynamic equation, where all system modes are controlled and spillover instability can be avoided. Using the active disturbance rejection control technique, two extended state observers are designed to obtain the estimation of external disturbances, which can be canceled in the negative feedback loop. The radial basis function neural network with adaptive weight law is employed to deal with the impact of input saturation. The well-posedness of the closed-loop system is proved by applying the semigroup theory. Under the rigorous Lyapunov analysis, the proposed control strategy ensures the practical stability of the rigid–flexible spacecraft system. Simulation verifies the performance of the designed control scheme.

Predictive generalised active disturbance rejection for load frequency control with communication delay

This paper formulates a generalised active disturbance rejection control technique based on Smith predictor (SP-GADRC) for power systems with communication delay. The SP-GADRC technique employs essential plant information and uses the notion of Smith predictor to alleviate the deterioration of transient response that arises due to the presence of communication delay in a system. The generalised formulae for computation of controller and observer gains for various single and multi-area power systems are derived. Furthermore, the effect of parametric uncertainty, nonlinearities, model-plant mismatch, load disturbances as well as varying time delay is examined to validate the robustness of the SP-GADRC technique. An elaborate comparative analysis is conducted with various existing approaches to exhibit efficacy of the SP-GADRC technique. The simulation results reveal that SP-GADRC scheme demonstrates an improved disturbance rejection ability, better transient performance and is robust to the presence of nonlinearities and disturbances in system.

A linear active disturbance rejection control technique for frequency control of networked microgrids

A linear active disturbance rejection control technique for frequency control of networked microgrids

Reduced Order Based Active Disturbance Rejection Controller Design with Applications

Active disturbance rejection control (ADRC) has emerged as a well-addressed controller design technique in recent years. It is a suitable replacement for the error-based feedback PID controller design approaches. The ADRC constitutes two controller design techniques: linear active disturbance rejection control (LADRC) and generalized active disturbance rejection control (GADRC). The LADRC design approach requires minimal information about the plant, while in the GADRC approach, detailed information about the plant is needed. For higher-order plants, the design of ADRC controllers and extended state observers may be pretty complex and costlier. So, the performance analysis of the higher order plant becomes difficult. Therefore, to make the controller simpler, it is always advantageous to reduce the controller size. This paper proposes reduced order linear active disturbance rejection control (ROLADRC), and reduced order generalized active disturbance rejection control (ROGADRC) techniques instead of full-order LADRC and GADRC approaches. The stability equation method (SEM) and other widespread model order reduction (MOR) methods are utilized to reduce the order of the plant. Further, ROLADRC and ROGADRC are compared with existing control techniques in the literature. The effectiveness of the proposed scheme is tested on the sun tracker system (STS) for position control and power systems for load frequency control (LFC).

Active disturbance rejection-based distributed containment control for stochastic nonlinear multiagent systems

ABSTRACT This paper investigates a distributed active disturbance rejection containment control problem for stochastic nonlinear multiagent systems under a directed topology. First, a class of nonlinear extended state observers predicated on the fractional power functions are proposed and extended state estimations are employed to compensate completely unknown stochastic terms and total disturbances in real time. Then the tracking differentiator is adopted to avoid the issue of computational burden caused by the repeated differentiation of virtual controllers. In light of the active disturbance rejection control technique, a distributed containment control scheme is put forward, which effectively deals with the problems of unknown nonlinearities and uncertain dynamics. Moreover, it is proved that containment errors of all followers converge to a small neighbourhood of the origin via the stochastic Lyapunov theory. Finally, the effectiveness of the proposed control method is verified by simulation results.