共查询到15条相似文献,搜索用时 109 毫秒
1.
2.
研究在含有控制时滞与测量时滞的系统在高速通讯网络下最优扰动抑制问题. 首先建立在高速通讯网络下含有控制时滞与测量时滞系统的离散化数学模型, 利用模型转换将时滞系统转化为形式上的无时滞系统. 然后通过求解离散Riccati方程和Stein方程设计含有状态反馈、扰动前馈和控制记忆项的最优控制律, 前馈项和控制记忆项分别补偿了扰动和控制时滞对系统性能的影响. 通过构造降维扰动状态观测器, 设计了含扰动前馈、输出反馈及
控制记忆项的动态控制律, 解决了前馈补偿器的物理不可实现问题. 仿真实例验证了所设计的最优控制律的有效性. 相似文献
3.
4.
5.
6.
研究线性时滞系统在外部正弦扰动作用下的前馈-反馈最优减振问题,提出了一种最优控制律的灵敏度设计方法.通过引入灵敏度参数并围绕它展开幂级数,将系统的最优控制问题简化为不含超前项和时滞项的两点边值问题族.通过截取最优控制级数的有限和获得原系统的前馈-反馈次优控制律.仿真结果表明,与经典状态反馈最优控制相比,本文的算法更加鲁棒,能更加有效地抑制正弦扰动. 相似文献
7.
研究一类受扰非线性系统的最优输出跟踪控制问题.给出了有限时域最优输出跟踪控制律的近似设计算法.首先将求解受扰非线性系统最优跟踪控制问题转换为求解状态向量与伴随向量耦合的非线性两点边值问题,然后利用逐次逼近方法构造序列将其转化为求解两个解耦的线性微分方程序列问题.通过迭代求解伴随向量的序列,可得到由解析的线性前馈-反馈控制部分和伴随向量的极限形式的非线性补偿部分组成的最优输出跟踪控制律.利用参考输入降维观测器和扰动降维观测器,解决了前馈控制的物理可实现问题.最后仿真结果表明了该方法的有效性. 相似文献
8.
带有持续扰动非线性系统的前馈- 反馈最优控制 总被引:5,自引:1,他引:5
研究具有外界持续扰动作用下非线性系统的最优控制问题,提出了一种设计前馈一反馈最优控制器的逐次逼近算法.利用该算法可将在扰动作用下的非线性系统的最优控制问题转化为求解线性非齐次两点边值序列的问题.得到的最优控制律由解析的线性前馈-反馈项和伴随向量序列极限形式的非线性补偿项组成.通过截取非线性补偿序列的有限项,可得到前馈-反馈次优控制律.仿真结果表明,该方法抑制外部持续扰动的鲁棒性优于经典反馈最优控制. 相似文献
9.
离散时滞系统的近似最优扰动抑制 总被引:1,自引:0,他引:1
研究了状态变量合有时滞的离散系统在外部扰动下的最优控制问题.通过引入一个灵敏度参数,将原系统的最优扰动抑制问题转化为一族不含超前项和时滞项的两点边值问题,并由此导出了最优扰动抑制控制器的这代近似设计方法.得到的最优扰动抑制控制律由解析的前馈一反馈项和伴随向量级数和形式的补偿项组成,截取伴随向量级数的有限和得到原系统的次优扰动抑制控制律.数值仿真表明该近似最优控制器对外部持续扰动具有良好的鲁棒性。 相似文献
10.
研究奇异摄动时滞系统在正弦扰动下的最优减振控制问题.基于奇异摄动的快慢分解理论,将原最优控制问题转化为无时滞快子问题和受扰线性时滞慢子问题,通过摄动法和前馈补偿技术求解时滞慢子系统的最优控制问题,得到了系统的前馈反馈组合控制(FFCC)律及其存在唯一性条件.FFCC律由线性解析项和共态向量无穷级数和表示的时滞补偿项组成,其中线性解析项可通过求解Riccati方程和Sylvester方程得到,时滞补偿项通过递推求解共态向量方程得到,仿真算例表明了方法的有效性. 相似文献
11.
Astolfi A. Kaliora G. Zhong-Ping Jiang 《Automatic Control, IEEE Transactions on》2005,50(9):1390-1396
In this note, we discuss the problems of output feedback stabilization for a class of cascaded systems and of (approximate and restricted) output regulation for general nonlinear systems. It is shown that (global) output feedback stabilization for a class of systems in feedforward form can be achieved with a dynamic feedback law, yielding bounded control, and relying on the introduction of a reduced-order observer. The above result, together with standard tools borrowed from the output regulator theory, is instrumental to construct dynamic control laws achieving (approximate) disturbance rejection and output tracking in the presence of (small) disturbance/reference signals generated by a known exosystem. 相似文献
12.
Active DIsturbance Rejection Control of Surface Vessels Using Composite Error Updated Extended State Observer 下载免费PDF全文
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. 相似文献
13.
Shi-Yuan Han Gong-You Tang Cheng-Ming Zhang 《International Journal of Control, Automation and Systems》2010,8(6):1330-1335
This paper considers the near-optimal tracking control problem for discrete-time systems with delayed input. Using a variable
transformation, the system with delayed input is transformed into a non-delayed system, and the quadratic performance index
of the optimal tracking control is transformed into a relevant format. The optimal tracking control law is constructed by
the solution of a Riccati matrix equation and a Stein matrix equation. A reduced-order observer is constructed to solve the
physically realizable problem of the feedforward compensator and a near-optimal tracking control is obtained. Simulation results
demonstrate the effectiveness of the optimal tracking control law. 相似文献
14.
This paper investigates the semi-global output feedback disturbance rejection control problem for a class of uncertain nonlinear systems with additive disturbances using linear sampled-data control. Aiming to reject the adverse effects caused by the uncertainties and unknown nonlinear perturbations which may not satisfy the strict feedback or feedforward structure, a new generalised discrete-time extended state observer is proposed to estimate the disturbance at sampling points. An output feedback disturbance rejection control law is then constructed in a sampled-data form which facilitates digital implementations. By selecting adequate control gains and a sufficiently small sampling period to restrain the state growth under a zero-order-hold input, the semi-global asymptotic stability of the hybrid closed-loop system and the disturbance rejection ability are proved. Both numerical example and an application of a single-link robot arm system demonstrate the feasibility and efficacy of the proposed method. 相似文献
15.
A novel robust flight control design method is proposed for a generic air-breathing hypersonic vehicle based on a state-dependent Riccati equation technique and a nonlinear disturbance observer. The highly nonlinear dynamics of the hypersonic vehicle are firstly brought to a linear structure having a state-dependent coefficient form. And then a state-dependent Riccati equation is solved at each sampling moment to obtain a nonlinear feedback optimal control law. In order to enhance robustness of the closed-loop system, a nonlinear disturbance observer is introduced to estimate the uncertainty caused by parametric variations and external disturbances. The resulting composite controller achieves not only promising robustness and disturbance rejection performance but also flexible adjustment in the response time. Compared to a Kriging controller, the proposed controller has great advantages in the system response time and robustness. The feasibility of the proposed method is validated by simulation results. 相似文献