共查询到19条相似文献,搜索用时 203 毫秒
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针对一类不确定非仿射非线性系统的跟踪控制问题, 提出一种鲁棒Backstepping 控制策略. 首先, 为利用仿 射非线性方法设计控制器, 给出一种适用于全局的非仿射非线性近似方法; 然后, 设计快速收敛非线性微分器以估计复合干扰和获取虚拟信号的微分, 进而给出不确定非仿射非线性系统的复合控制器, 其中鲁棒项和阻尼项分别用于减少逼近误差和近似方法中动态误差对系统跟踪的影响; 最后, 通过仿真实验验证了所提出方法的有效性. 相似文献
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对于可状态反馈线性化的一类仿射非线性系统,本文提出一种非线性鲁棒控制的μ方法。首先给出非线性鲁棒控制问题,然后利用状态反馈线性化方法,把非线性系统线性化,并利用μ综合方法,对线性化系统进行鲁棒控制器的设计,最后通过回代构成非线性鲁棒控制系统。 相似文献
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推力矢量飞机纵向鲁棒动态逆控制 总被引:2,自引:1,他引:1
针对推力矢量飞机大迎角飞行纵向控制,提出一种鲁棒动态逆方法。对时标分离非线性动态逆的内外回路控制结构进行修改,通过坐标变换得到一个弱非线性系统;然后对该系统模型的已知部分和不确定部分同时进行小扰动线性化,转化得到线性不确定系统;在此基础上利用??综合方法设计鲁棒控制器。该方法能够为非线性动态逆控制提供鲁棒稳定性和鲁棒性能保证,并可回避时标分离问题。仿真结果验证了所提出方法的有效性。 相似文献
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由于永磁直线同步电机(PMLSM)伺服系统应用于一些高精密场合,因此克服系统存在的负载扰动、参数变化等不确定性影响是提高系统性能的关键.针对不确定性问题,采用一种基于自适应模糊控制器(AFC)和非线性扰动观测器(NDO)的反馈线性化控制方法.首先设计反馈线性化控制器(FLC)实现系统的线性化,便于位置跟踪;其次采用NDO估计并补偿系统的不确定性,提高跟踪精度.但在实际运行过程中观测器增益较难选取,极易产生较大的观测误差,为此,采用AFC方法逼近NDO的观测误差,通过自适应律动态调整模糊规则,改善模糊控制器的学习能力,增强系统的鲁棒性,并用李雅普诺夫定理保证系统闭环稳定性.实验结果表明,与基于DOB和NDO的反馈线性化位置控制相比,该方法能够明显提高系统的跟踪性和鲁棒性. 相似文献
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高超声速飞行器非线性鲁棒控制律设计 总被引:1,自引:0,他引:1
高超声速飞行器具有模型非线性程度高、耦合程度强、参数不确定性大、抗干扰能力弱等特点,其自主控制具有较大的挑战.论文提出了一种基于鲁棒补偿技术和反馈线性化方法的非线性鲁棒控制方法.文中首先采用反馈线性化的方法对纵向模型进行输入输出线性化,实现速度和高度通道的解耦和非线性模型的线性化.针对得到的线性模型,设计包括标称控制器和鲁棒补偿器的线性控制器.基于极点配置原理,设计标称控制器使标称线性系统具有期望的输入输出特性,利用鲁棒补偿器来抑制参数不确定性和外界扰动对于闭环控制系统的影响.基于小增益定理,证明了闭环控制系统的鲁棒稳定性和鲁棒跟踪性能.相比于非线性回路成形控制方法,仿真结果表明了所设计非线性鲁棒控制算法的有效性和优越性. 相似文献
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This article investigates the robust adaptive control system design for the longitudinal dynamics of a flexible air‐breathing hypersonic vehicle (FAHV) subject to parametric uncertainties and control input constraints. A combination of back‐stepping and nonlinear disturbance observer (NDO) is utilized for exploiting an adaptive output‐feedback controller to provide robust tracking of velocity and altitude reference trajectories in the presence of flexible effects and system uncertainties. The dynamic surface control is introduced to solve the problem of “explosion of terms.” A new NDO is developed to guarantee the proposed controller's disturbance attenuation ability and to performance robustness against uncertain aerodynamic coefficients. To deal with the problem of actuator saturation, a novel auxiliary system is exploited to compensate the desired control laws. The stability of the presented NDO and controller is analyzed. Simulation results are given to demonstrate the effectiveness of the presented control strategy. 相似文献
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In this paper, we consider the robust adaptive tracking control of uncertain multi-input and multi-output (MIMO) nonlinear systems with input saturation and unknown external disturbance. The nonlinear disturbance observer (NDO) is employed to tackle the system uncertainty as well as the external disturbance. To handle the input saturation, an auxiliary system is constructed as a saturation compensator. By using the backstepping technique and the dynamic surface method, a robust adaptive tracking control scheme is developed. The closed-loop system is proved to be uniformly ultimately bounded thorough Lyapunov stability analysis. Simulation results with application to an unmanned aerial vehicle (UAV) demonstrate the effectiveness of the proposed robust control scheme. 相似文献
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针对传统移动电站存在励磁、调速控制相互独立、缺乏联系的不足,研究和建立了励磁及机电复合调速非线性模型,提出了基于状态参数双重强跟踪滤波估计的非线性鲁棒综合控制策略.采用双重强跟踪滤波的方法,实现了模型中关键状态参量的间接获取,依据多输入多输出系统的精确反馈线性化、非线性鲁棒控制理论,对励磁、机电复合调速综合控制律进行了推导,并进行了仿真验证.仿真结果表明:负载突变时,强跟踪滤波能够快速跟踪和估计状态参数;在外部干扰存在情况下,通过求解线性矩阵不等式,本文得到的控制律在保证励磁、转速控制系统稳定的同时,能够实现L2增益干扰抑制. 相似文献
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To tackle the trajectory tracking problem and achieve high control accuracy in many actual nonlinear systems with unknown dynamics and input saturation, a novel discrete-time extended state observer-based model-free adaptive constrained sliding mode control with modified prescribed performance is investigated via compact-form dynamic linearization (CFDL) and partial-form dynamic linearization (PFDL). Firstly, the original non-affine system is turned into an affine one comprising an unknown nonlinear term and a linearly parametric term affine to the input via both PFDL and CFDL. Then, a discrete-time extended state observer (DESO) is used to estimate the lumped disturbance containing the unknown nonlinear time-varying term and the term relevant to the estimation error of pseudo partial derivative (PPD) parameter. Furthermore, a modified prescribed performance function is introduced in the model-free adaptive sliding mode control scheme to keep the output tracking error in the prescribed bound without causing any asymmetric offset error in the steady-state. Meanwhile, to suppress the influence of input saturation on the control system, an anti-windup compensator is used. Finally, rigorous theoretical analyses show the robust convergence of the tracking error via the proposed CFDL and PFDL-based methods under external disturbances. Simulations verify the superiority of the modified prescribed performance function, DESO, and anti-windup compensator in the proposed method. Also, the effects of the PFDL-based method and the CFDL-based one are compared during the simulation. 相似文献
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基于小波逼近的非线性系统鲁棒迭代学习控制 总被引:3,自引:0,他引:3
针对存在扰动的未知非线性系统,利用小波逼近将系统参数化,结合变结构控制技术,
提出了一种鲁棒迭代学习控制算法.该算法采用迭代学习的方式修正小波逼近的系数,利用具
有死区的滑模变结构技术保证算法的鲁棒收敛性.收敛性分析表明,每次迭代学习都将减小所
得到的逼近系数与最佳系数的差异.因此,期望轨迹变化后,该算法针对以前轨迹的学习结果仍
然可以起作用,部分克服了传统迭代学习控制的学习结果仅对某一特定轨迹有效的缺点. 相似文献
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This paper presents the derivation of robust trajectory‐tracking nonlinear control laws for general three‐dimensional vehicle models with one degree of underactuation where all of the state tracking errors are stabilized. The method is based on a novel transformation of the trajectory tracking problem into a reduced‐order error dynamics. Two traditional nonlinear controllers based on sliding mode and backstepping approaches are developed and shown to stabilize the trajectory tracking errors in presence of modeling uncertainties and bounded disturbances. The performance of the two controllers are compared in absence and presence of disturbances. 相似文献