共查询到18条相似文献,搜索用时 203 毫秒
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对离散时间系统的H∞ 干扰衰减问题进行了研究 .以回路传递恢复 (LTR)技术和H∞ 控制理论为基础 ,给出了一种新的离散时间H∞/LTR综合方法 .这种方法包含两个设计步骤 :首先设计一个H∞ 状态反馈控制器 ,以使系统在鲁棒稳定性和干扰衰减特征方面满足设计指标 ;其次设计观测器 ,使得上一步中所获得的H∞ 状态反馈系统的特性得以恢复 . 相似文献
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考虑系统外界干扰、系统参数摄动等非线性扰动环节对中立型时滞系统的H∞影响,提出基于Lyapunov稳定性理论的鲁棒H∞控制器的设计思想.利用线性矩阵不等式(LMI)方法,给出了该类具有状态非线性不确定性中立型时滞系统的鲁棒∞控制器的设计实例.在非线性不确定函数满足增益有界的条件下,得到了该类时滞系统满足鲁棒∞性能的一个充分条件.通过求解一个线性矩阵不等式LMI,即可获得鲁棒∞控制器.仿真结果表明了基于Lyapunov稳定性理论,LMI技术设计的控制器克服了系统外界非线性干扰或系统本身非线性参数摄动的影响,实现了闭环系统的H∞性能条件下的渐近稳定,满足了该系统鲁棒H∞控制的要求. 相似文献
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轧机驱动电机与轧辊间采用长轴连接,连接轴刚度有限,因此在带材高速轧制时,常规电流、转速双闭环控制易产生机电振动和断带现象.为了抑制机电振动,保证对干扰有良好的动态抑制作用且无静态扰动误差,同时使系统具有鲁棒稳定性,将内模原理与H∞控制理论相结合,通过选取适当的加权函数,设计了轧机主传动系统机电振动鲁棒控制器,为了能方便地在实际工程中实现复杂的H∞控制器,采用PID控制器逼近所得高阶控制器.同时为了改善控制系统的跟踪性能,在H∞控制器的基础上设计了两自由度控制器,有效减小了系统的超调.仿真研究结果表明:该方法不仅有效抑制了轧机主传动系统的机电振动,而且减小了轧制负荷扰动引起的动态速降. 相似文献
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研究一类广义时变系统的鲁棒H2/H∞滤波器的设计问题。 利用具有参数依赖的Lyapunov函数,结合线性矩阵不等式分别给出了使滤波误差系统容许且满足H∞性能约束的充分条件、使滤波误差系统容许且满足H2性能约束的充分条件以及使滤波误差系统容许且满足H2/H∞性能指标的充分条件。 基于该具有参数依赖Lyapunov函数的鲁棒H2/H∞性能准则推导出鲁棒H2/H∞滤波器存在的充分条件,并将滤波器的设计问题转化为线性矩阵不等式约束优化问题。 最后通过数值算例表明该方法的有效性。 相似文献
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The disturbance observer (DOB)‐based controller is widely used to estimate and suppress disturbance in motion control system. Because the low‐pass filter (Q‐filter) in DOB decides the performances of disturbance suppression, noise rejection, and robust stability against system uncertainties, design of Q‐filter is the principal task in DOB construction. This paper presents a systematic scheme for Q‐filter design based on H∞ norm optimization. Cost function for optimization is proposed by considering performance and relative order condition of the Q‐filter. The norm minimization problem is then transformed to a standard H∞ control problem. Furthermore, the relationship between performance and frequency weighting functions is investigated based on which selection of weighting functions is presented. Simulation results validate the global optimality and systematicness of the proposed method. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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Kyoungchul Kong Masayoshi Tomizuka 《International Journal of Control, Automation and Systems》2013,11(1):12-20
Disturbance observer-based control systems often encounter the stability problem due to modeling uncertainties. In such cases, the disturbance observer (DOB) may have to be re-designed by narrowing the bandwidth of the Q-filter to enhance stability robustness, but this approach to stability enhancement deteriorates the performance of DOB. In order to improve robust stability while maintaining the performance of DOB, this paper proposes a method that manipulates the nominal plant model in the DOB; the parameters of the discretized nominal model are optimized to improve robust stability in the discrete time domain. For the optimization of nominal model, it is assumed that the closed-loop poles of DOB are subjected to multiplicative uncertainties, and the maximum allowable magnitude of uncertainties is utilized as the measure of stability robustness. Then, the proposed method changes the location of closed-loop poles to maximize the robustness margin. This paper provides a case study that includes experimental results. 相似文献
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针对一类不确定时滞受扰系统,研究了在执行器发生故障情况下系统具有保代价的H∞鲁棒可靠控制器设计问题。根据Lyapunov稳定性理论,得到了系统存在保代价H∞鲁棒可靠控制器应满足的一个矩阵不等式,进一步将这个矩阵不等式转化为线性矩阵不等式(LMI),并给出了系统状态反馈控制器的设计方法。利用论文方法设计的鲁棒可靠控制器能够使得时滞系统对于任意允许的不确定量以及一个预先指定执行器子集中任意执行器失效不仅具有鲁棒容错性,并且使系统存在保成本上界以及具有指定H∞范数的干扰抑制能力。仿真结果表明了该可靠控制器设计方法的有效性。 相似文献
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采用改进型扰动观测器的控制方法 总被引:3,自引:0,他引:3
提出一种适用于非最小相位对象的改进型扰动观测(DOB)结构.通过新增两个控制器,该结构不但对标称性能控制器输出进行动态补偿,而且还补偿了系统输出反馈信号.因此,基于新DOB的控制结构不但能在低频段很好的抑制外部干扰,消除实际被控模型摄动对闭环系统的输出性能的影响,更重要的是提高了抑制高频测量噪声的能力.最后,讨论了该控制结构的内部稳定性和鲁棒稳定性. 相似文献
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Jiang Wang Shaoming He Defu Lin 《International Journal of Control, Automation and Systems》2016,14(6):1475-1483
This paper presents a new composite robust controller for a class of uncertain nonlinear systems through backstepping method and disturbance observer (DOB) technique. By designing a generalized disturbance observer (GDOB), the mismatched/matched uncertainty is estimated and compensated at each backstepping step. By virtue of the proposed GDOB, the proposed controller only requires the lumped uncertainties are differentiable and the higher-order derivatives are bounded. With the help of GDOB, the high-gain backstepping controller is also avoided completely. Asymptotical stability of the closed-loop system is established using direct Lyapunov method. An illustrative example of missile autopilot design is given and simulations are carried out to validate the proposed method. 相似文献
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Juhoon Back Author Vitae 《Automatica》2008,44(10):2528-2537
The linear disturbance observer (DOB) approach has been successfully employed as a tool for robust control and disturbance rejection in practice. In this paper, we present a nonlinear DOB which inherits all the benefits of the classical linear DOB approach. In particular, we prove that the proposed nonlinear DOB recovers not only the steady-state performance but also the transient performance of the nominal closed-loop system under plant uncertainties and input disturbances. One novel feature of the proposed controller is that it is an add-on type inner-loop output-feedback controller; thus any type of outer-loop controller can be combined to enhance the closed-loop system performance. Our result is a semi-global one and the stability proof is given when the nonlinear system has a well-defined relative degree with a stable zero dynamics. 相似文献
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基于Lyapunov稳定性理论,研究一类同时具有状态非线性不确定和线性不确定时变时滞系统的鲁棒控制器的设计问题。在非线性不确定性满足增益有界条件下,得到该类时变时滞系统依赖于时变延迟导数的最大值的满足鲁棒H∞性能的一个充分条件。通过求解一个线性矩阵不等式-LMI,即可获得鲁棒H∞控制器。给出的两个具体算例说明该方法的有效性。 相似文献