异步电动机自适应矢量控制系统

针对经典的矢量控制系统中磁链观测器的参数偏差影响系统稳态性能和动态性能的不足,提出了把自适应控制融合到矢量控制当中的策略,设计了转子磁链自适应观测器,得出了异步电动机的转子磁链自适应观测器的算法,构成转速与磁链闭环的矢量控制系统.仿真结果表明,该系统具有一定的鲁棒性和较好的稳、动态性能.     

基于自适应滑模观测器的永磁同步电机无位置传感器控制研究

永磁同步电机无位置传感器控制多基于高频信号注入法或状态观测器法。文中在分析变结构系统的基础上，结合表面式永磁同步电机在a、b坐标下的数学模型提出1种自适应滑模观测器估算电机转子位置与转速，并得到观测器的收敛条件，推导和建立了估算的自适应率，利用李亚普诺夫理论证明了算法的收敛性。该方法克服了传统基于电机模型的无位置传感器控制方法对电机参数的依赖性，观测器的稳定性不受电机参数变化及负载扰动的影响，具有较强的鲁棒性。以表面式永磁同步电机为应用实例进行的仿真与实验结果验证了该方法理论分析的正确性与实现的可行性。     

带负载转矩补偿的 PMSM 交流伺服系统自适应控制

设计了一个基于ＤＳＰ和ＰＭＳＭ自适应速度控制器，使用了模型参考自适应方法，具有计算量小的特点，能实时辨识系统参数，采用自适应负载转矩观测器补偿负载转矩扰动，实验表明本控制器在系统参数变化和负载转矩扰动的情况下具有良好的自适应能力。     

永磁同步伺服电机的变结构智能控制

提出了一种基于智能控制的离散变结构系统，该系统采用一种新的状态观测器的设计方法，首先设计一个性能观测器，随后用神经网络对其具有不确定性的部分进行补偿，并用神经网络实现对变结构控制器参数的在线调整，在永磁同步伺服电机位置控制系统中的实际应用，表明了该方法的优越性和实用性。     

基于自适应滑模观测器的永磁同步电动机无位置传感器控制

对于永磁同步电动机(PMSM)调速系统，转子位置是获得可靠控制所必需的。但位置传感器不仅会显著增加系统费用和测量噪声，且无法应用在一些恶劣环境。基于PMSM定子两相电压一电流模型，提出一种基于自适应滑模观测器的无位置传感器控制方法，对参数和负载变化具有较强的鲁棒性。仿真结果表明该观测器在中高速范围内具有良好的转子位置和速度估算性能。     

基于自适应观测器牵引电机定子铁耗辨识

铁耗等效电阻是识别定子铁心故障的有效参数。对其进行在线辨识能有效监测定子铁心状态。在考虑铁耗的牵引电机串联铁耗模型的基础上,提出一种基于自适应观测器的在线辨识牵引电机定子铁耗等效电阻的方法。该方法通过构建自适应观测器在线辨识等效铁耗电阻。采用LMI工具箱设计自适应观测器的反馈增益矩阵,消除极点配置方法导致观测器出现不稳定的现象。实验结果表明该方法具有结构简单,鲁棒性强,全速稳定的优点。     

电磁轴承系统中组合型磁通观测器自适应切换方法

为了解决组合型磁通观测器中的切换点设置对观测器及磁通型功率放大器性能的影响,提高组合型磁通观测器的观测性能,分析了组合型磁通观测器的切换点与系统参数及观测器性能之间的关系,给出了切换点最优化设计的方法。针对组合型磁通观测器的最优切换点随着系统参数的变化而改变从而造成观测器性能的下降的问题,基于模糊控制理论提出了一种切换点自适应调整方法,结合切换点最优化设计方法,对组合型磁通观测器的切换点进行实时在线的调整,提高了组合型磁通观测器的性能和磁通观测的准确度。     

飞行机器人递归小脑神经网络模型分解控制

为解决一类不确定非线性系统的控制问题及系统混合干扰上界在实际应用中难以测量的问题,提出递归小脑神经网络模型分解控制算法.将系统分为名义模型、结构不确定性和非结构不确定性,分别对名义模型设计直接反馈控制器、对结构不确定性设计自适应控制器、对非结构不确定性设计鲁棒控制器.设计递归小脑模型关节控制器作为观测器来对系统干扰的上...     

基于鲁棒自适应状态观测器的异步电机磁链估计抗扰性研究

针对传统全阶磁链观测器随内、外扰动导致磁链估测精度不高甚至系统不稳定的问题,对观测器极点分布情况和内、外扰动对系统的影响进行研究分析,从而对反馈矩阵增益系数的取值进行设计,提出了一种鲁棒自适应状态观测器对磁链进行估计。当遇到内、外扰动时,在保持系统稳定的情况下自动减小反馈增益系数以减小扰动对系统的影响,从而保持系统良好的动静态性能。在内、外扰动下,将鲁棒自适应状态观测器与传统的全阶磁链观测器的磁链估计精度、转速波动以及转矩波动进行比较分析。仿真和试验结果表明:鲁棒自适应状态观测器具有比传统全阶磁链观测器更好的抗干扰性能。     

新型自适应速度观测器在矢量控制中的应用

实现高性能矢量控制系统的重要环节是准确地观测异步电机的转子磁链。将一种新型的速度自适应磁链闭环观测器应用于矢量控制系统中，取代了传统的积分器。理论证明，该系统是超稳定系统。仿真表明，该方案电机磁链观测精度高，电机参数鲁棒性好，同时基于磁链观测器所设计的速度自适应辨识方案准确性好，收敛速度快，使系统在较低转速下仍能保持优良的性能。本系统以1．1kW异步电机为控制对象，并采用MATLAB／Simulink软件对系统进行了仿真。     

Adaptive observers for a class of multi-output non-linear systems

Sufficient differential geometric conditions are given for the existence of global adaptive observers for a class of multi-output non-linear systems which are linear with respect to a vector of unknown constant parameters. They extend to multi-output systems earlier results on adaptive observers for single-output systems; they also extend to systems with unknown parameters results obtained previously on the existence of non-adaptive observers with linear error dynamics.     

Composite adaptive anti‐disturbance resilient control for Markovian jump systems with partly known transition rate and multiple disturbances

In this paper, the problem of composite adaptive anti‐disturbance resilient control is investigated for Markovian jump systems with partly known transition rate and multiple disturbances. The considered multiple disturbances include two types: one is external disturbance, while the other is an unexpected nonlinear signal which is described as a nonlinear function. Composite adaptive disturbance observers are constructed to estimate these disturbances, and the estimations are applied to feedforward compensation. Then a composite adaptive anti‐disturbance resilient controller is obtained. Furthermore, some sufficient conditions are presented in terms of linear matrix inequalities such that the closed‐loop system is stochastically stable with performance. Finally, a numerical example and an application example are given to illustrate the effectiveness of the proposed approach. Copyright © 2016 John Wiley & Sons, Ltd.     

Composite adaptive disturbance observer‐based control for a class of nonlinear systems with multisource disturbance

Antidisturbance control and estimation problem are introduced for a class of nonlinear system subject to multisource disturbances. The uncertain multisource disturbances consist of not only a single harmonic or constant disturbance but also another unexpected nonlinear signal described as a nonlinear function. The composite adaptive disturbance observers are constructed separately from the controller design to estimate the disturbance with partial known information. By integrating disturbance observer‐based controller with robust adaptive control, a novel type of composite adaptive disturbance observer‐based control scheme is presented for a class of nonlinear system with multisource disturbances. Simulations for a flight control system are given to demonstrate the effectiveness of the results compared with the previous schemes. Copyright © 2012 John Wiley & Sons, Ltd.     

An adaptive observer for joint estimation of states and parameters in both state and output equations

An adaptive observer is a recursive algorithm for joint state–parameter estimation of parameterized state‐space systems. Previous works on globally convergent adaptive observers consider unknown parameters either in state equations or in output equations, but not in both of them. In this paper, a new adaptive observer is designed for linear time‐varying systems with unknown parameters in both state and output equations. Its global convergence for simultaneous estimation of states and parameters is formally established under appropriate assumptions. A numerical example is presented to illustrate the performance of this adaptive observer. Copyright © 2011 John Wiley & Sons, Ltd.     

Adaptive observer for a class of nonlinear systems with time‐varying delays

The adaptive observer design problems have been extensively studied in literature for both linear and nonlinear systems. Some researches have also been carried out on adaptive observer design for linear time‐delay systems, but there is no significant work on adaptive observer design for nonlinear time‐delay systems. In this work, the adaptive observer design problem for a class of nonlinear time‐delay systems is considered. The observer is designed for the nonlinear systems whose nonlinear functions satisfy Lipschitz condition. Like conventional adaptive observers for the systems without time delays, this observer also estimates both states and unknown parameters simultaneously. For this property, it will be very much useful for many real‐time systems where time delays cannot be avoided. The sufficient conditions for existence of the observer are derived using the linear matrix inequality approach. With the help of a numerical example, effectiveness of the proposed observer is demonstrated. Copyright © 2012 John Wiley & Sons, Ltd.     

Robust fault detection and adaptive parameter identification for DC-DC converters via switched systems

In this paper, the problem of fault detection and identification for DC-DC converters is presented. First, switched systems model and fault model are analyzed based the switched characteristics of the DC-DC converters, taking the DC-DC buck converter as an example. According to the switched Lyapunov function technique, a fault detection observer and a bank of linear switched fault identification observers are designed for the switched systems. Next, the fault detection observer detects the fault based on the residual produced by the observer output and actual output. After the fault is detected, fault identification observers are activated. The location of fault is identified by comparing the residual evaluation functions. Meanwhile, the adaptive parameter identification is achieved by choosing an appropriate adaptive law. Finally, in order to show the feasibility of the fault detection and identification, the simulation results are given in this article.     

Disturbance observer-based adaptive boundary iterative learning control for a rigid-flexible manipulator with input backlash and endpoint constraint

In this article, an observer-based adaptive boundary iterative learning control law is developed for a class of two-link rigid-flexible manipulator with input backlash, the unknown external disturbance, and the endpoint constraint. To tackle the backlash nonlinearities and ensure the vibration suppression, the disturbance observers based upon the iterative learning conception are considered in the adaptive boundary control design. A barrier Lyapunov function is incorporated with boundary control law to restrict the endpoint state. Based on the defined barrier composite energy function, the tracking angle error convergence of the rigid part is guaranteed, and the vibrations of the flexible part are suppressed through the rigorous analysis. Finally, a numerical simulation is provided to illustrate the effectiveness of the proposed control.     

Geometry of adaptive control: optimization and geodesics

Two incompatible topologies appear in the study of adaptive systems: the graph topology in control design, and the coefficient topology in system identification. Their incompatibility is manifest in the stabilization problem of adaptive control. We argue that this problem can be approached by changing the geometry of the sets of control systems under consideration: estimating n_p parameters in an n_p‐dimensional manifold whose points all correspond to stabilizable systems. One way to construct the manifold is using the properties of the algebraic Riccati equation. Parameter estimation can be approached as an optimal control problem akin to the deterministic Kalman filter, leading to algorithms that can be used in conjunction with standard observers and controllers to construct stable adaptive systems. Copyright © 2004 John Wiley & Sons, Ltd.     

Adaptive observer design for uncertain nonlinear ODE-PDE cascades

We are revisiting the problem of adaptive observer design for systems that are constituted of an Ordinary Differential Equation (ODE), containing a globally Lipschitz function of the state, and a linear Partial Differential Equation (PDE) of a diffusion–reaction heat type. The ODE and PDE are connected in series and both are subject to parametric uncertainties. In addition to nonlinearity and uncertainty, the system complexity also lies in the fact that no sensor can be implemented at the junction point between the ODE and the PDE. In the absence of parameter uncertainty, nonadaptive state observers are available featuring exponential convergence. However, convergence is guaranteed only under the condition that either the Lipschitz coefficient is sufficiently small or the PDE domain length is sufficiently small. To get around this limitation, and also to account for parameter uncertainty, we develop a design that involves two concatenated adaptive observers, covering the two subintervals of the PDE domain. The proposed design employs one extra sensor, providing the measurement of the PDE state at an inner position close to the ODE-PDE junction point. Both observers are shown to be exponentially convergent, under ad-hoc persistent excitation (PE) conditions, with no limitation on the Lipschitz coefficient and domain length.     

Adaptive cooperative control for air-ground systems with actuator saturation under disturbances

In this article, an adaptive cooperative control strategy is proposed for an air-ground system with actuator saturation. The air-ground system with actuator saturation includes a ground vehicle with road bumps and a quadrotor with gust winds. The adaptive cooperative control strategy is composed of four tracking differentiators, four adaptive extended state observers and two adaptive integral SMC laws. Based on Silverman canonical transformation and pole placement, the adaptive extended state observers are designed to estimate disturbances from the road bumps and gust winds. The adaptive integral SMC laws are proposed to achieve cooperation between the ground vehicle and the quadrotor in the air-ground system with actuator saturation. Simulation results are provided to show effectiveness of the adaptive cooperative control strategy by a ground vehicle and a quadrotor.