Active disturbance rejection control for power plant with a single loop

The cascade proportional‐integral‐derivative (PID) control method is widely used in power plant control field. In this paper, an active disturbance rejection control (ADRC) for a power plant with a single loop is introduced for eliminating the shortcomings of the cascade PID control method. The proposed controller based on the ADRC method consists of a tracking differentiator (TD), an extended state observer (ESO) and a nonlinear combination of errors. In this approach, the processes with higher orders, uncertainties and unmodeled dynamics are viewed as lower‐ordered systems with general disturbances, and the general disturbances are estimated by ESO, and then actively compensated. Besides, only one measured output is needed in the proposed method instead of two or three in the cascade PID control method. Some simulation studies compared with the regular cascade PID control method show the proposed method has better performance beyond the regular cascade PID control method. Copyright © 2010 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society     

结晶器多变量耦合系统的自抗扰控制

主要研究新颖实用非线性自抗扰控制算法,在结晶器多变量耦合系统中的应用.自抗扰控制主要特性是实时估计对象模型摄动和外扰的总和作用量,并在控制信号中补偿掉,实现不确定性强非线性对象的实时动态反馈线性化.结合控制对象,建立了结晶器多变量耦合自抗扰控制系统.数值仿真试验表明自抗扰耦合控制的协调性、自适应跟随性和抗干扰性优于传统的PID解耦控制.     

基于扩张状态观测器的分散模型预测控制

针对复杂关联系统中分散控制方法无法有效解决子系统间的耦合和干扰问题, 提出一种基于扩张状态观测器的分散模型预测控制算法. 首先将复杂关联系统分解为多个状态维数较低、控制变量较少的子系统, 并为每个子系统设计本地预测控制器; 然后, 采用扩张状态观测器对子系统的耦合项以及干扰项进行估计, 进而利用估计值对子系统进行前馈补偿, 从而降低复杂关联系统的计算复杂度, 提高系统的稳定性和抗干扰能力; 最后, 利用液位控制系统验证了所提出算法的有效性.

     

不同重力环境的空间机械臂自抗扰轨迹跟踪控制

针对空间机械臂在地面装调与空间应用时,由于重力环境变化导致机械臂模型发生变化的问题,提出了一种自抗扰控制算法,用于完成空间机械臂轨迹跟踪控制的任务.该算法通过将系统模型及未知外扰作为系统的总和扰动,并利用扩张状态观测器对该扰动进行观测且给予补偿,从而提高了系统抗扰的性能.当机械臂模型随重力环境变化而发生变化时,使用同一个自抗扰控制器对其末端轨迹进行控制,均能取得较好的控制效果.通过对系统的稳定性进行分析,证明了所设计控制器的有效性.将仿真结果与PD控制及自适应鲁棒控制做比较,结果表明该控制算法不仅能适应机械臂模型的变化而且还能有效抵抗系统的扰动,从而使系统具有较强的鲁棒性.     

Active disturbance rejection control approach to stabilization of lower triangular systems with uncertainty

In this paper, we apply the active disturbance rejection control (ADRC) to stabilization for lower triangular nonlinear systems with large uncertainties. We first design an extended state observer (ESO) to estimate the state and the uncertainty, in real time, simultaneously. The constant gain and the time‐varying gain are used in ESO design separately. The uncertainty is then compensated in the feedback loop. The practical stability for the closed‐loop system with constant gain ESO and the asymptotic stability with time‐varying gain ESO are proven. The constant gain ESO can deal with larger class of nonlinear systems but causes the peaking value near the initial stage that can be reduced significantly by time‐varying gain ESO. The nature of estimation/cancelation makes the ADRC very different from high‐gain control where the high gain is used in both observer and feedback. Copyright © 2015 John Wiley & Sons, Ltd.     

Dual closed‐loop tracking control for wheeled mobile robots via active disturbance rejection control and model predictive control

A dual closed‐loop tracking control is proposed for a wheeled mobile robot based on active disturbance rejection control (ADRC) and model predictive control (MPC). In the inner loop system, the ADRC scheme with an extended state observer (ESO) is proposed to estimate and compensate external disturbances. In the outer loop system, the MPC strategy is developed to generate a desired velocity for the inner loop dynamic system subject to a diamond‐shaped input constraint. Both effectiveness and stability analysis are given for the ESO and the dual closed‐loop system, respectively. Simulation results demonstrate the performances of the proposed control scheme.     

大射电望远镜馈源指向系统轨迹跟踪自抗扰控制

采用独立控制策略实现新一代大射电望远镜馈源指向跟踪系统的高精度轨迹跟踪 .将两组成子系统之间的动力学耦合及其他扰动视为对精调Stewart平台子系统的未知扰动 ,设计了强鲁棒自抗扰控制器实现扰动补偿 .大射电望远镜馈源指向系统 5 0m缩比模型实验 ,验证了独立控制策略和自抗扰控制器的工程有效性和可行性 .为将来建造新一代大射电望远镜工程奠定了坚实的基础     

Active DIsturbance Rejection Control of Surface Vessels Using Composite Error Updated Extended State Observer

In this paper, a composite‐errors‐based active disturbance rejection control law is proposed for surface vessels with exogeneous disturbances. The low‐frequency disturbances from wind, wave and ocean currents are estimated by a novel composite‐errors‐based extended state observer (ESO). Since the composite errors are composed of trajectory tracking errors and estimation errors, the disturbance rejection control is feedforward‐feedback composite control. The advantages of feedforward control and feedback control are exploited to reject system disturbances. Compared with conventional ESO‐based active disturbance rejection control, smaller estimation errors and smaller tracking errors can be achieved by the proposed disturbance compensation control. The effectiveness and superiority of the designed control law are illustrated by theoretical analysis and simulation results.     

基于优化模型补偿自抗扰的伺服控制方法研究

在永磁同步电机(PMSM)自抗扰控制器(ADRC)系统中,扩张状态观测器(ESO)在扰动较多且幅值变化大时难以保证估计精度,而普通的模型补偿自抗扰控制器的性能又受到参数辨识精度和辨识算法复杂度的限制.针对该问题,提出一种伺服系统优化的模型补偿自抗扰控制方法.以交轴电流和实际转速作为线性扩张状态观测器(LESO)输入,采用二阶LESO对系统总扰动进行观测,将此观测值作为补偿模型补偿到速度环ADRC的ESO中,并在控制量的扰动补偿项中去除该补偿模型,实现模型补偿的目的.仿真和实验结果表明,该方法显著降低了ADRC中ESO要估计量的变化幅度,提高了扰动估计精度,同时不需要进行额外的参数辨识,可实时在线获取补偿模型,具有较好的动态特性与抗扰动能力.     

基于最小拍观测器的自抗扰控制器设计与性能分析

自抗扰控制器设计中,扩张状态观测器需要较高的观测带宽,才能更快的观测出状态变量.本文采用最小拍观测器,使得其具有最快的观测速度.以2阶系统为例,得到了离散系统下,基于最小拍观测器的自抗扰控制器的等价复合控制模型,其开环补偿器等价为超前校正器.仿真结果表明,基于最小拍观测器的自抗扰控制器可以最快的观测出系统状态变量,且控制器带宽的选取一般应小于采样周期的倒数.由于不再需要设计观测器带宽,从而简化了参数设计.     

基于微分预报的机载雷达稳定平台自抗扰控制系统

为了进一步提高机载雷达稳定平台的抗干扰能力,以满足其愈来愈高的精度需求;提出一种基于“先微分,后预报”的机载雷达稳定平台自抗扰控制方案;对比于传统自抗扰控制器,此方案将扩张状态观测器的扰动观测输出通过微分预报之后在补偿系统的扰动,有效地减少了扰动估计滞后的现象,显著提高了对系统扰动补偿的实时性;通过Matlab仿真实验表明,“先微分,后预报”自抗扰控制方案的超调量仅有1.11%,稳态时间只有0.52 s,远远小于PID控制,而其对扰动的响应幅值仅为PID控制的12.8%,且与PID控制相比,其对连续扰动的抑制能力更为优秀。     

航天器姿态自抗扰控制

为抑制航天器自身结构参数变化和内外扰动对姿态控制精度和姿态稳定度的影响, 设计了航天器姿态自抗扰控制器. 自抗扰控制器(ADRC)由跟踪微分器(TD)、扩张状态观测器(ESO)和姿态反馈控制器(AFC)3部分组成.跟踪微分器负责安排姿态指令过渡过程, 并提取其微分信号. 扩张状态观测器(ESO)充分利用姿态敏感器与速率陀螺的量测信息, 可对航天器姿态及内部和外部干扰进行观测. 姿态反馈控制器则在补偿ESO估计的干扰的同时,实现航天器的姿态控制. 与已有研究相比, 扩张状态观测器采用复合量测信息对状态估计进行校正, 性能较好. 而自抗扰控制器只采用一个环路即可实现姿态控制及干扰补偿, 结构简单. 对某航天器姿态控制系统的仿真结果表明,以上自抗扰控制器是可行的.     

坦克炮控系统摩擦扰动补偿研究

针对坦克水平向炮控伺服系统中存在的摩擦不确定因素及未建模动态,首先建立水平向炮控伺服系统的数学模型,将摩擦扰动和未建模动态视为一个综合扰动项,然后利用扩张状态观测器对综合扰动项进行观测和补偿,并将扩张状态观测器(ESO)补偿回路作为经典PID控制方法的内回路,实现ESO-PID的复合控制;最后对所用方法进行仿真,结果表明,在原有控制方法的基础上设计控制器,集合了PID控制算法的"被动抗扰"和自抗扰控制方法中扩张状态观测器的"主动抗扰"特性,能够在保持控制系统原有特性的基础上大幅度提高炮控系统的稳定精度以及低速性能。     

高动态离心机系统的自抗扰控制设计

针对传统PID在控制高速精密离心机系统时难以满足其高动态过程的要求,对系统目标过渡过程进行安排并设计了自抗扰控制器.所提出的自抗扰控制器包括3个部分:跟踪微分器、扩张状态观测器和误差反馈控制器.由于离心机在启动和制动阶段,系统状态会经历一个快速变化的过程,所以在离心机系统动态变化阶段采用跟踪微分器对目标函数进行过渡过程安排,防止系统出现过大超调;并且设计了扩张状态观测器对系统未知干扰进行估计和补偿;补偿后采用误差反馈控制器实现离心机系统高动态过程的跟踪控制.最后通过对自抗扰控制进行参数整定,使得系统满足所提出的各项性能指标要求.仿真结果验证了相比于传统PID控制,所提出的自抗扰控制器在超调量,调节时间以及稳态控制精度等性能指标上具有优越性.     

无刷双馈电机自抗扰控制方法

针对无刷双馈电机非线性强耦合特性, 提出一种实现其高性能控制的自抗扰控制方法. 在控制电机同步坐标系下, 设计磁链自抗扰控制器和转速自抗扰控制器, 对系统内部的耦合影响和系统外部扰动进行观测和补偿, 实现非线性系统线性化控制. 该控制器具有较强的鲁棒性, 且不依赖电机模型. 仿真对比结果表明, 自抗扰控制器能够准确地估计和补偿系统的内外扰动, 控制精度高, 抗扰能力强, 能够实现磁链和电磁转矩的解耦, 进而实现磁链和转速相互独立控制, 是一种简单有效的高性能控制方法.

     

Active disturbance rejection control approach to output‐feedback stabilization of lower triangular nonlinear systems with stochastic uncertainty

In this paper, we apply the active disturbance rejection control approach to output‐feedback stabilization for uncertain lower triangular nonlinear systems with stochastic inverse dynamics and stochastic disturbance. We first design an extended state observer (ESO) to estimate both unmeasured states and stochastic total disturbance that includes unknown system dynamics, unknown stochastic inverse dynamics, external stochastic disturbance, and uncertainty caused by the deviation of control parameter from its nominal value. The stochastic total disturbance is then compensated in the feedback loop. The constant gain and the time‐varying gain are used in ESO design separately. The mean square practical stability for the closed‐loop system with constant gain ESO and the mean square asymptotic stability with time‐varying gain ESO are developed, respectively. Some numerical simulations are presented to demonstrate the effectiveness of the proposed output‐feedback control scheme. Copyright © 2016 John Wiley & Sons, Ltd.     

Disturbance-observer-based speed control for SPMSM drives using modified super-twisting algorithm and extended state observer

To address the robust speed control problem of the surface-mounted permanent-magnet synchronous motor (SPMSM) drive, a novel composite speed controller (CSC) is proposed, which consists of the modified super-twisting sliding-mode SC (STSM-SC) and the extended state observer (ESO). Regarding the motion dynamics of the SPMSM drive, the unmodeled dynamics, endogenous, and exogenous disturbances are lumped together as the total disturbance. The ESO-based feedforward compensation mechanism is used to deal with the total disturbance for the robustness improvement of the speed control achieved by the modified STSM-SC-based feedback regulation mechanism. On the basis of the field-oriented control strategy, performance comparisons of the standard STSM-SC, the ESO-based standard STSM-SC, the modified STSM-SC, and the proposed CSC are carried out on a suitably developed experimental setup. The experimental results are presented to validate the superiority of the proposed CSC.     

宏微复合运动平台的自抗扰控制研究

摩擦是影响机械导轨运动平台精度的主要原因.宏微复合运动平台将无摩擦的柔性铰链与直线平台结合在一起,利用柔性铰链的弹性变形补偿摩擦死区.然而,柔性铰链的固有频率低,其非线性弹性振动严重影响微平台定位精度.为此,本文设计视弹性振动为扰动的自抗扰控制策略,该方法避免了建立非线性弹性振动精准数学模型的困难,利用扩张状态观测器主动估计弹性振动及不确定性,并在微平台位置环补偿之,以保证微平台定位精度.与此同时,在控制律中加入加速度前馈以提高系统响应速度.对于宏平台,采用PID控制作为宏平台位置环的控制策略,并通过宏微双级驱动方式补偿受机械导轨非线性摩擦带来的影响.实验对比结果表明,自抗扰控制在受非线性弹性振动影响时,其抗扰性能、跟踪性能优于传统的PID控制,可保证微平台良好的定位精度.     

内模控制框架下时延系统扩张状态观测器参数整定

作为一种有效的控制设计方法, 自抗扰控制研究获得了广泛关注, 然而针对自抗扰控制器的参数整定方法则相对较少. 本文针对一阶惯性加延迟系统, 将线性自抗扰控制转化为内模控制结构, 导出了其中控制器、滤波器、乘性不确定性、互补灵敏度函数的对应表达式, 随后, 利用频域鲁棒稳定性判据, 分析了自抗扰控制器核心—–扩张状态观测器的参数对闭环系统稳定性的影响. 基于该分析, 总结出一阶惯性加延迟系统扩张状态观测器的两条参数整定准则. 数值仿真结果验证了该整定准则的有效性.     

基于扩张状态观测器和有限时间控制的感应电机直接转矩控制

对感应电机直接转矩控制系统中存在的干扰,本文结合扩张状态观测器(ESO)和有限时间控制(FTC)提出一种复合控制方法来提高系统的抗干扰能力.首先采用扩张状态观测器估算系统的扰动,用此观测值作为前馈量补偿到输入端;然后运用连续有限时间控制方法设计系统前向通道中的反馈控制器.文中对控制器的稳定性进行了证明.与传统的PI控制以及P+ESO控制方法进行仿真与实验结果比较,验证了方法的有效性.