Disturbances rejection optimization based on improved two-degree-of-freedom LADRC for permanent magnet synchronous motor systems

Permanent magnet synchronous motor(PMSM)speed control systems with conventional linear active disturbance rejection control(CLADRC)strategy encounter issues regarding the coupling between dynamic response and disturbance suppression and have poor performance in suppressing complex nonlinear disturbances.In order to address these issues,this paper proposes an improved two-degree-of-freedom LADRC(TDOF-LADRC)strategy,which can enhance the disturbance rejection performance of the system while decoupling entirely the system's dynamic and anti-disturbance performance to boost the system robustness and simplify controller parameter tuning.PMSM models that consider total disturbances are developed to design the TDOF-LADRC speed controller accurately.Moreover,to evaluate the control performance of the TDOF-LADRC strategy,its stability is proven,and the influence of each controller parameter on the system control performance is analyzed.Based on it,a comparison is made between the disturbance observation ability and anti-disturbance performance of TDOF-LADRC and CLADRC to prove the superiority of TDOF-LADRC in rejecting disturbances.Finally,experiments are performed on a 750 W PMSM experimental platform,and the results demonstrate that the proposed TDOF-LADRC exhibits the properties of two degrees of freedom and improves the disturbance rejection performance of the PMSM system.

Active disturbance rejection control on first-order plant

Conventional PI control encounters some problems when dealing with large lag process in the presence of parameter uncertainties.For the typical first-order process,an observerbased linear active disturbance rejection control（LADRC） scheme is presented to cope with the difficulties,and a reduced-order observer scheme is proposed further.Some quantitative dynamic results with regard to non-overshoot characteristics are obtained.Finally,the performance boundaries of LADRC and PI control are explicitly compared with each other,which shows that the former is more superior in most cases.

Active Disturbance Rejection Control for a Multiple-Flexible-Link Manipulator

The control problem of multiple-flexible-link manipulators( MFLMs) is studied in this paper.The dynamic model of MFLM is derived and separated into two-time scale by utilizing the singular perturbation technique. The active disturbance rejection control( ADRC) is adopted to the slow subsystem to track a desired trajectory. The proposed ADRC structure preshapes the desired trajectory by utilizing the tracking differentiator,estimates the disturbance and internal states with an extended state observer,and guarantees a robust performance by combining a feedback controller with a feedforward term. Two types of feedback controllers are designed,proportional derivative( PD) controller and nonlinear PD( NPD) controller. For the fast subsystem,a fast stabilizing control is designed according to the standard linear quadratic regulator approach. Simulations are performed to evaluate the proposed control scheme.Results show that,compared with the traditional PD controller,the ADRC structure based control scheme has smaller overshot and shorter settling time,suppresses vibration quickly,and is robust to the maneuver speed. In general,the control scheme utilizing ADRC structure and NPD feedback controller shows better performance.

Active disturbance rejection control for precise position tracking of piezoelectric actuators

Positioning with high precision piezoelectric actuators is widely used.To overcome positioning inaccuracy caused by hysteresis and creep of actuators,a precise tracking method for piezoelectric actuators using active disturbance rejection control(ADRC) has been proposed in this paper.This method,in real-time,actively estimates and compensates parameter uncertainties,nonlinear factors such as hysteresis,and external disturbances in the tracking system.Precise tracking of the piezoelectric actuator can be achieved without any form of feedforward compensations.The experimental results demonstrate that the active disturbance rejection controller can reduce tracking errors by over90%comparing with those using the PID controller.Those features of the proposed control method are very suitable for applications in adaptive optics.

Fractional Order Linear Active Disturbance Rejection Control for Linear Flexible Joint System

A linear flexible joint system using fractional order linear active disturbance rejection control is studied in this paper.With this control scheme,the performance against disturbances,uncertainties,and attenuation is enhanced.Linear active disturbance rejection control(LADRC)is mainly based on an extended state observer(ESO)technology.A fractional integral(FOI)action is combined with the LADRC technique which proposes a hybrid control scheme like FO-LADRC.Incorporating this FOI action improves the robustness of the standard LADRC.The set-point tracking of the proposed FO-LADRC scheme is designed by Bode’s ideal transfer function(BITF)based robust closed-loop concept,an appropriate pole placement method.The effectiveness of the proposed FO-LADRC scheme is illustrated through experimental results on the linear flexible joint system(LFJS).The results show the enhancement of the robustness with disturbance rejection.Furthermore,a comparative analysis is presented with the results obtained using the integer-order LADRC and FO-LADRC scheme.

Active Disturbance Rejection Control for Uncertain Nonlinear Systems With Sporadic Measurements

This paper deals with the problem of active disturbance rejection control(ADRC)design for a class of uncertain nonlinear systems with sporadic measurements.A novel extended state observer(ESO)is designed in a cascade form consisting of a continuous time estimator,a continuous observation error predictor,and a reset compensator.The proposed ESO estimates not only the system state but also the total uncertainty,which may include the effects of the external perturbation,the parametric uncertainty,and the unknown nonlinear dynamics.Such a reset compensator,whose state is reset to zero whenever a new measurement arrives,is used to calibrate the predictor.Due to the cascade structure,the resulting error dynamics system is presented in a non-hybrid form,and accordingly,analyzed in a general sampled-data system framework.Based on the output of the ESO,a continuous ADRC law is then developed.The convergence of the resulting closed-loop system is proved under given conditions.Two numerical simulations demonstrate the effectiveness of the proposed control method.

Multi-Objective Optimization for Active Disturbance Rejection Control for the ALSTOM Benchmark Problem

Based on a thing that it is difficult to choose the parameters of active disturbance rejection control for the non-linear ALSTOM gasifier, multi-objective optimization algorithm is applied in the choose of parameters. Simulation results show that performance tests in load change and coal quality change achieve better dynamic responses and larger scales of rejecting coal quality disturbances. The study provides an alternative to choose parameters for other control schemes of the ALSTOM gasifier.

Compensated acceleration feedback based active disturbance rejection control for launch vehicles

In this paper, the attitude tracking and load relief control problems against wind disturbances and uncertain aerodynamics as well as the engine thrust of launch vehicles are studied.Firstly, a framework of Compensated Acceleration Feedback based Active Disturbance Rejection Control(CAF-ADRC) is established to achieve both desired attitude tracking and load relief performances. In particular, the total disturbance that includes the effects caused by both aerocoefficient perturbations and disturbances is estimated by constructing an Extended State Observer(ESO) to achieve attitude tracking. Furthermore, combined with the normal acceleration due to the engine thrust, the accelerometer measurement is also compensated to enhance the load relief effect.Secondly, the quantitative analysis of ESO and the entire closed-loop system are studied. It can be concluded that the desired attitude tracking and load relief performances can be achieved simultaneously under the proposed approach. Besides, tuning laws of the proposed approach are systematically given, which are divided into ESO, Proportional Derivative(PD) and Compensated Acceleration Feedback(CAF) modules. Moreover, the performances under CAF-ADRC approach can be better than those under CAF based PD(CAF-PD) approach by tuning load relief gain.Finally, the approach presented is applied to a typical control problem of launch vehicles with wind disturbances and parameter uncertainties.

Control of Linear Servo Carts with Integral-Based Disturbance Rejection

This paper describes a system designed for linear servo cart systems that employs an integral-based Linear Active Disturbance Rejection Control(ILADRC)scheme to detect and respond to disturbances.The upgrade in this control technique provides extensive immunity to uncertainties,attenuation,internal disturbances,and external sources of noise.The fundamental technology base of LADRC is Extended State Observer(ESO).LADRC,when combined with Integral action,becomes a hybrid control technique,namely ILADRC.Setpoint tracking is based on Bode’s Ideal Transfer Function(BITF)in this proposed ILADRC technique.This proves to be a very robust and appropriate pole placement scheme.The proposed LSC system has experimented with the hybrid ILADRC technique plotted the results.From the results,it is evident that the proposed ILADRC scheme enhances the robustness of the LSC system with remarkable disturbance rejection.Furthermore,the results of a linear quadratic regulator(LQR)and ILADRC schemes are comparatively analyzed.This analysis deduced the improved performance of ILADRC over the LQR control scheme.

面向天线跟踪系统的ADRC控制器设计及参数优化

针对传统自抗扰控制器存在参数整定困难及控制器效果有待改善的问题,提出了一种基于改进型Fal函数的永磁同步电机位置自抗扰控制器控制策略,旨在优化伺服系统的控制效果。设计了Le_fal函数以解决Fal函数在定义域区间的不连续性问题和拐点处输出增益的抖动问题,减少了控制器待整定参数。针对自抗扰控制器参数难以整定的问题,采用粒子群算法对控制器参数进行优化。仿真实验结果表明,基于粒子群的改进型自抗扰控制器参数优化算法将超调量从传统自抗扰控制器的3.1016%降低至0.3375%,将调节时间从3.08 s降低到0.47 s,将稳态误差从0.0633降低至0.0162。结果表明,改进后的自抗扰控制器具有更好的快速性和鲁棒性。

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

Disconnections due to voltage drops in the grid cannot be permitted if wind turbines(WTs)contribute significantly to electricity pro-duction,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.

ADRC-GPC算法在旋转倒立摆系统中的应用

自抗扰广义预测控制(ADRC-GPC)是一种由广义预测控制技术和自抗扰控制技术有机结合的新型控制算法。该算法首先利用扩张状态观测器(ESO)估计出系统的总扰动;其次,引入虚拟控制量以抵消该总扰动作用,使原被控对象系统转化为积分器串联型系统;最后,利用GPC对新系统进行收敛控制。ADRC-GPC不仅可以有效避免传统GPC的在线计算量过大问题,还无须使用状态量的高阶信息,相比传统ADRC大大降低了调参难度。针对一级旋转倒立摆稳定控制问题中的强耦合、非线性等难点,设计了双通道ADRC-GPC融合控制器。仿真实验结果表明:ADRC-GPC控制器能够使一级旋转倒立摆系统达到控制目的,其对多变量非线性不稳定系统具有良好的控制性能。

Bandwidth Based Stability Analysis of Active Disturbance Rejection Control for Nonlinear Uncertain Systems

This paper focuses on the stability analysis of the active disturbance rejection control (ADRC)for a class of uncertain systems.To overcome the difficulty of defining a reasonable Lyapunov function and setting limitations of system parameters,the converse Lyapunov theorem and the disturbance theory are employed.This paper proves that the estimation error of the extended state observer (ESO)and the tracking error of the closed-loop system using ADRC are uniformly ultimately bounded and monotonously diminishing with the increase of their respective bandwidth,so that the stability of the ADRC system could be performed.In order to further illustrate the relationship between the stability range and bandwidths,it analyzes quantitatively the performance of ESO and ADRC based on the root locus and the step response.Finally,an example based on a typical control system is carried out,and simulation results verify the theoretical analysis proved in this paper.

A multi-strategy pigeon-inspired optimization approach to active disturbance rejection control parameters tuning for vertical take-off and landing fixed-wing UAV

In this paper.Active Disturbance Rejection Control(ADRC)is utilized in the pitch control of a vertical take-off and landing fixed-wing Unmanned Aerial Vehicle(UAV)to address the problem of height fluctuation during the transition from hover to level flight.Considering the difficulty of parameter tuning of ADRC as well as the requirement of accuracy and rapidity of the controller,a Multi-Strategy Pigeon-Inspired Optimization(MSPIO)algorithm is employed.Particle Swarm Optimization(PSO),Genetic Algorithm(GA),the basic Pigeon-Inspired Optimization(PIO),and an improved PIO algorithm CMPIO are compared.In addition,the optimized ADRC control system is compared with the pure Proportional-Integral-Derivative(PID)control system and the non-optimized ADRC control system.The effectiveness of the designed control strategy for forward transition is verified and the faster convergence speed and better exploitation ability of the proposed MSPIO algorithm are confirmed by simulation results.

Transfer function analysis and implementation of active disturbance rejection control

To support the adoption of active disturbance rejeetion control(ADRC)in industrial practice,this article aims at improv-ing both understanding and implementation of ADRC using traditional means,in particular via transfer functions and a frequency-domain view.First,to enable an immediate comparability with existing classical control solutions,a realizable transfer function implementation of continous-time linear ADRC is introduced.Second,a frequency-domain analysis of ADRC components,performance,parameter sensitivity,and tuning method is performed.Finally,an exact implementation of discrete-time ADRC using transfer functions is introduced for the first time,with special emphasis on practical aspects such as computational fficiency,low parameter footprint.and windup protection.

Fractional-Order Proportional-Integral-Derivative Linear Active Disturbance Rejection Control Design and Parameter Optimization for Hypersonic Vehicles with Actuator Faults

The hypersonic vehicle model is characterized by strong coupling,nonlinearity,and acute changes of aerodynamic parameters,which are challenging for control system design.This study investigates a novel compound control scheme that combines the advantages of the Fractional-Order Proportional-Integral-Derivative(FOPID)controller and Linear Active Disturbance Rejection Control(LADRC)for reentry flight control of hypersonic vehicles with actuator faults.First,given that the controller has adjustable parameters,the frequency-domain analysis-method-based parameter tuning strategy is utilized for the FOPID controller and LADRC method(FOLADRC).Then,the influences of the actuator model on the anti-disturbance capability and parameter tuning of the FOLADRC-based closed-loop control system are analyzed.Finally,the simulation results indicate that the proposed FOLADRC approach has satisfactory performance in terms of rapidity,accuracy,and robustness under the normal operating condition and actuator fault condition.

Design and stability analysis of a generalized reduced-order active disturbance rejection controller

Disturbance and uncertainty rejection is a key objective in control system design, and active disturbance rejection control(ADRC)exactly provides an effective solution to this issue. To this end, this paper presents a generalized active disturbance rejection controller for a class of nonlinear uncertain systems with linear output. To be specific, a generalized reduced-order extended state observer(ESO) is proposed to reduce phase delay and complexity of the system, which can take full advantage of the system output. Also, this method includes the existing results with fewer assumptions, and can be applied to systems with any order measurable states or multiple states, even linear combination states. Furthermore, the stability of this approach is guaranteed and demonstrated through matrix transformation and Lyapunov method, and design examples and numerical simulations are given to show the effectiveness and practicability of the method.

基于ADRC的LCC-S谐振型无线充电副边闭环控制研究

针对磁耦合谐振式LCC-S无线充电系统工作过程中易受外界或自身参数扰动的影响导致输出电流、电压偏离目标值的问题,以及如何快速准确地对扰动情况做出反应,提出一种基于自抗扰控制ADRC(active disturbance rejection control)的副边恒流恒压二段式闭环控制方法。首先,通过电路分析研究了LCC-S型谐振网络的输出特性与系统参数的关系;其次,为实现闭环精准调控系统输出,建立副边Buck变换器的状态方程模型,并根据模型设计ADRC中跟踪微分器、扩张状态观测器和非线性状态误差反馈;最后,搭建基于ADRC的无线充电实验平台,在多参数扰动下比较ADRC控制器与PI控制器的控制效果,结果表明,ADRC控制器表现出更好的动态调节能力。

Active Disturbance Rejection Controller Based Heading Control of Underwater Flight Vehicles

The total disturbance estimated by the extended state observer(ESO)in active disturbance rejection controller(ADRC)is affected greatly by measurement noise when the control step is small in heading control of underwater flight vehicles(UFVs).In order to prevent rudder from high-frequency chattering caused by measurement noise,a tracking-differentiator(TD)is integrated to the ESO to develop an improved ADRC scheme.The improved ADRC suppresses the impact of sensor noise.Both the results of simulations and tank tests show the effectiveness of improved ADRC based heading control.

基于ADRC的四臂桥驱动伺服系统死区效应补偿

为了降低死区效应对伺服电机驱动系统的影响,对驱动电路进行设计、分析的基础上,引入自抗扰控制并串联内模状态观测器加以优化,对产生的死区进行补偿。首先,提出了一种四臂桥变换器驱动电路拓扑结构,分析了臂桥产生的死区电压规律。提出齿隙死区模型,分析齿隙死区对系统的影响;其次,将扩张状态观测器与内含内模原理的观测器串联,设计出可降阶的新型死区补偿控制器;最后,将改进的自抗扰控制策略应用于四臂桥驱动伺服电机齿隙死区模型,改善系统性能。结果表明,引入改进自抗扰控制器后,死区效应对伺服系统的影响降低了约40%,系统抗干扰能力增强,补偿效果稳定。