共查询到17条相似文献,搜索用时 44 毫秒
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针对相对阶为2的多变量系统,利用高频增益矩阵分解,在适当的假设下,建立了新的参数模型,设计出具有未规范化自适应律的直接型模型参考自适应控制器,保证了闭环系统所有信号的有界性和跟踪误差的收敛性.仿真实例验证了控制方案的有效性. 相似文献
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针对传统自适应控制系统设计的自适应律参数收敛慢进而影响控制系统瞬态性能的问题,研究一类新的基于参数估计误差修正的鲁棒自适应律设计.首先引入滤波操作给出参数估计误差的提取方法,构建出含参数估计误差修正项的自适应律,进而将该自适应律用于控制器设计和分析中,可同时实现控制误差和参数估计误差指数收敛.对比分析了几类传统自适应律和所提出自适应律的收敛性和鲁棒性,并给出了保证参数收敛所需持续激励条件的一种直观、简便的在线判别方法.数值仿真及基于自制三自由度直升机系统俯仰轴实验结果表明,基于参数误差修正的自适应律及控制器可得到优于传统自适应方法的跟踪控制和参数估计性能. 相似文献
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永磁同步电机的模型参考自适应反步控制 总被引:5,自引:1,他引:4
基于转子磁场定向坐标系下的永磁同步电机(PMSM)模型,提出一种PMSM的模型参考自适应反步控制方法.该方法采用线性参考模型来给出控制系统的性能规范,通过定义虚拟控制和选择适当的Lyapunov函数来保证整个系统的稳定性,进而导出系统控制律及参数自适应律.系统可在电机参数变化和负载扰动的情况下,渐近跟踪参考模型给出的转速和定子电流信号.仿真结果证实了该方法的有效性. 相似文献
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离散时间直接型模型参考自适应控制 总被引:1,自引:0,他引:1
本文针对一类离散时间系统, 研究了具有规范化自适应律的直接型模型参考自适应控制 (MRAC). 我们重新证明了离散时间系统的输入与输出间的 Lp 范数与 L2δ 范数关系特性和离散时间的交换引理 1 与引理 2. 并建立了离散时间自适应律的性质, 定义了规范化信号, 把闭环系统中的所有信号与其建立联系. 从而, 正如连续时间系统一样, 以一种系统化的方法严格分析了离散时间 MRAC 方案的稳定性与收敛性. 相似文献
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Robust direct model reference adaptive control using KP = LDU factorization for multivariable plants
Motivated by the idea of high frequency gain matrix KP ?=?LDU factorization, the purpose of this paper is to study the problem of robust direct model reference adaptive control for more general multivariable plants with unmodeled dynamics and disturbances. For multivariable plants, by reproving some properties similar to those in robust adaptive control theory for SISO plants and redefining the normalizing signal, the relationship between all the signals in the closed-loop plant and the normalizing signal can be established, and the stability and robustness of the closed-loop plant are analyzed rigorously from a qualitative point of view. 相似文献
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For a large class of discrete-time multivariable plants with arbitrary relative degrees, the design and analysis of the direct model reference adaptive control scheme are investigated under less restrictive assumptions. The algorithm is based on a new parametrization derived from the high frequency gain matrix factorization Kp=LDU under the condition that the signs of the leading principal minors of/fp are known. By reproving the discrete-time Lp and L2σ norm relationship between inputs and outputs, establishing the properties of discrete-time adaptive law, defining the normalizing signal, and relating the signal with all signals in the closed-loop system, the stability and convergence of the discrete-time multivariable model reference adaptive control scheme are analyzed rigorously in a systematic fashion as in the continuous-time case. 相似文献
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W. R. Cluett 《Systems & Control Letters》1988,11(2)
This paper discusses the role of normalization with respect to robust parameter estimation for discrete-time adaptive control in the presence of unmodeled dynamics. It is pointed out that the normalizing signal may be brought into the adaptive law in two distinct ways; (i) via normalization of the regressor and the error signal in the standard parameter update law, and (ii) by replacement of the error signal with a function of the normalizing signal and the error. The convergence properties for both approaches are derived and shown to be similar. 相似文献
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This paper studies design and implementation of an enhanced multivariable adaptive control scheme for an uncertain nonlinear process exposed to actuator faults. For adaptive fault compensation, a model reference adaptive control (MRAC) strategy is utilized as main controller. A new adaptation algorithm making possible to improve transient performance of adaptive control is integrated to the controller. With the help of further modifications, some restrictive conditions on multivariable adaptive design are relaxed so that the system requires less plant information. The resulting controller has a simpler structure than the other matrix factorization based controllers. At the final stage of design, a robust adaptive control scheme is obtained with consideration of practical implementation problems such as sensor noises, external disturbances and unmodeled system dynamics. It is proved that the controller guarantees closed-loop signal boundedness and asymptotic output tracking. Real-time experiment results acquired from quadruple tank benchmark system are presented in order to exhibit the effectiveness of the proposed scheme. 相似文献
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Xue-Jun Xie 《International journal of systems science》2013,44(3):265-278
For a class of MIMO systems with input and output unmodeled dynamics, bounded disturbances and any relative degree, using the idea of Kp = L 2 D 2 S 2 factorization, the design and analysis of robust direct model reference adaptive control are further investigated in this article. By establishing the Lp and L 2δ relationship properties between the input and output, multivariable swapping lemmas and relating all the signals in the closed-loop system with the normalizing signal, stability and robustness of adaptive system are analyzed rigorously. Compared with the existing results, the proof procedure is more compact and simple. A simulation example verifies the effectiveness of the control scheme. 相似文献
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For a class of nonlinear systems with dynamic uncertainties,
robust adaptive stabilization problem is considered in this paper.
Firstly, by introducing an observer, an augmented system is
obtained. Based on the system, we construct an exp-ISpS Lyapunov
function for the unmodeled dynamics, prove that the unmodeled
dynamics is exp-ISpS, and then obtain a dynamic normalizing signal
to counteract the dynamic disturbances. By the backstepping
technique, an adaptive controller is given, it is proved that all
the signals in the adaptive control system are globally uniformly
ultimately bounded, and the output can be regulated to the origin
with any prescribed accuracy. A simulation example further
demonstrates the efficiency of the control scheme. 相似文献
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This note presents a general stability proof for continuous-time adaptive control, with very general assumptions on the identifier and controller. We show that if the exogenous input signal is rich enough, then both the identifier and the controller converge to their "true" values. Applications of the proof to pole placement design and design based on the factorization approach are discussed. 相似文献