ADRC FRACTIONAL ORDER PID CONTROLLER DESIGN OF HYPERSONIC FLIGHT VEHICLE

Active disturbance rejection controller（ADRC）uses tracking-differentiator（TD）to solve the contradiction between the overshoot and the rapid nature.Fractional order proportion integral derivative（PID）controller improves the control quality and expands the stable region of the system parameters.ADRC fractional order（ADRFO）PID controller is designed by combining ADRC with the fractional order PID and applied to reentry attitude control of hypersonic vehicle.Simulation results show that ADRFO PID controller has better control effect and greater stable region for the strong nonlinear model of hypersonic flight vehicle under the influence of external disturbance,and has stronger robustness against the perturbation in system parameters.

Generalized-Extended-State-Observer and Equivalent-Input-Disturbance Methods for Active Disturbance Rejection: Deep Observation and Comparison

Active disturbance-rejection methods are effective in estimating and rejecting disturbances in both transient and steady-state responses.This paper presents a deep observation on and a comparison between two of those methods:the generalized extended-state observer(GESO)and the equivalent input disturbance(EID)from assumptions,system configurations,stability conditions,system design,disturbance-rejection performance,and extensibility.A time-domain index is introduced to assess the disturbance-rejection performance.A detailed observation of disturbance-suppression mechanisms reveals the superiority of the EID approach over the GESO method.A comparison between these two methods shows that assumptions on disturbances are more practical and the adjustment of disturbance-rejection performance is easier for the EID approach than for the GESO method.

Adaptive linear active disturbance-rejection control strategy reduces the impulse current of compressed air energy storage connected to the grid

The merits of compressed air energy storage(CAES)include large power generation capacity,long service life,and environmental safety.When a CAES plant is switched to the grid-connected mode and participates in grid regulation,using the traditional control mode with low accuracy can result in excess grid-connected impulse current and junction voltage.This occurs because the CAES output voltage does not match the frequency,amplitude,and phase of the power grid voltage.Therefore,an adaptive linear active disturbance-rejection control(A-LADRC)strategy was proposed.Based on the LADRC strategy,which is more accurate than the traditional proportional integral controller,the proposed controller is enhanced to allow adaptive adjustment of bandwidth parameters,resulting in improved accuracy and response speed.The problem of large impulse current when CAES is switched to the grid-connected mode is addressed,and the frequency fluctuation is reduced.Finally,the effectiveness of the proposed strategy in reducing the impact of CAES on the grid connection was verified using a hardware-in-the-loop simulation platform.The influence of the k value in the adaptive-adjustment formula on the A-LADRC was analyzed through simulation.The anti-interference performance of the control was verified by increasing and decreasing the load during the presynchronization process.

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.

Research on improved active disturbance rejection control of continuous rotary motor electro-hydraulic servo system

In order to meet the precision requirements and tracking performance of the continuous rotary motor electro-hydraulic servo system under unknown strong non-linear and uncertain strong disturbance factors,such as dynamic uncertainty and parameter perturbation,an improved active disturbance rejection control(ADRC)strategy was proposed.The state space model of the fifth order closed-loop system was established based on the principle of valve-controlled hydraulic motor.Then the three parts of ADRC were improved by parameter perturbation and external disturbance;the fast tracking differentiator was introduced into linear and non-linear combinations;the nonlinear state error feedback was proposed using synovial control;the extended state observer was determined by nonlinear compensation.In addition,the grey wolf algorithm was used to set the parameters of the three parts.The simulation and experimental results show that the improved ADRC can realize the system frequency 12 Hz when the tracking accuracy and response speed meet the requirements of double ten indexes,which lay foundation for the motor application.

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.

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.

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.

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。

Depth control for a deep-sea self-holding intelligent buoy system based on active disturbance rejection control method

The net buoyancy of the deep-sea self-holding intelligent buoy(DSIB)will change with depth due to pressure hull deformation in the deep submergence process.The net buoyancy changes will affect the hovering performance of the DSIB.To make the DSIB have better resistance to the external disturbances caused by the net buoyancy and water resistance,a depth controller was designed to improve the depth positioning based on the active disturbance rejection control(ADRC).Firstly,a dynamic model was established based on the motion analysis of the DSIB.In addition,the extended state observer(ESO)and nonlinear state error feedback controller were designed based on the Lyapunov stability principle.Finally,semi-physical simulations for the depth control process were made by using the ADRC depth controller and traditional PID depth controller,respectively.The results of the semi-physical simulations indicate that the depth controller based on the ADRC can achieve the predefined depth control under the external disturbances.Compared with the traditional PID depth controller,the overshoot of the ADRC depth controller is 1.74%,and the depth error is within 0.5%.It not only has a better control capability to restrain the overshoot and shock caused by the external disturbances,but also can improve intelligence of the DSIB under the depth tracking task.

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.

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.

基于PIO-ADRC的自主水下航行器运动控制

为进一步提高自主水下航行器(Autonomous Underwater Vehicle,AUV)的控制精度,对六自由度全驱动AUV进行建模,并搭建相应的自抗扰控制器(Active Disturbance Rejection Controller,ADRC)。考虑到传统ADRC待调整参数过多,且必须随着系统进行相应的参数调整,针对此,提出基于鸽群算法优化(Pigeon-Inspired Optimization,PIO)的ADRC(PIO-ADRC),并在相同仿真条件下将其与经过PIO的比例-积分-微分(Pigeon-Inspired Optimized Proportional Integral Derivative,PIO-PID)控制器和传统ADRC的控制效果进行对比。结果表明,使用PIO的ADRC超调量小、稳态误差小、控制效率更高。

Path tracking for vehicle parallel parking based on ADRC controller

A novel path tracking controller for parallel parking based on active disturbance rejection control （ADRC） was presented in this paper. A second order ADRC controller was used to solve the path tracking robustness, which can estimate and compensate model uncertainty caused by steering kinematics and disturbances caused by parking speed and steering system delay. Collision-free path planning technology was adopted to generate the reference path. The simulation results validate that the performance of the proposed path tracking controller is better than the conventional PID controller. The actual vehicle tests show that the proposed path tracking controller is effective and robust to model uncertainty and disturbances.

基于MPC及改进ADRC的车辆自适应巡航控制研究

针对车辆纵向运动时内部和外部扰动导致的预期功能稳定性问题,基于模型预测控制(Model Predictive Control, MPC)及改进自抗扰控制(Active Disturbance Rejection Control, ADRC),设计了一种车辆自适应巡航控制(Adaptive Cruise Control, ACC)策略。首先,建立车辆运动学模型以及考虑前车速度的安全车间距离模型;然后,设计模型预测控制器和改进自抗扰控制器,利用MPC算法实现对前车的跟踪,并将状态误差作为改进自抗扰控制器的输入,实现车辆在扰动环境下的稳定巡航控制;最后,进行仿真对比实验。结果表明,基于MPC及改进ADRC的车辆自适应巡航控制策略能够有效抑制由于距离误差引起的系统内部扰动和外部扰动,提高车辆在自适应巡航过程中的跟踪性能以及系统的稳定性。

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。

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.

High AOA decoupling control for aircraft based on ADRC

In this paper, a practical decoupling control scheme for fighter aircraft is proposed to achieve high angle of attack(AOA)tracking and super maneuver action by utilizing the thrust vector technology. Firstly, a six degree-of-freedom(DOF) nonlinear model with 12 variables is given. Due to low sufficiency of the aerodynamic actuators at high AOA, a thrust vector model with rotatable engine nozzles is derived. Secondly, the active disturbance rejection control(ADRC) is used to realize a three-channel decoupling control such that a strong coupling between different channels can be treated as total disturbance, which is estimated by the designed extended state observer. The control surface allocation is implemented by the traditional daisy chain method. Finally,the effectiveness of the presented control strategy is demonstrated by some numerical simulation results.

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。