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针对相对阶为1的理想系统,本文考虑了具有混杂自适应律的间接型模型参考自适应控制问题.通过建立系统和控制器的离散参数估计和它们的插值四者之间关系的性质,严格地分析了闭环系统的稳定性,证明了闭环系统中所有的信号都一致有界,并且跟踪误差渐进收敛于零. 相似文献
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考虑连续时变系统的直接自适应控制问题。研究带有δ-修正算法的自适应律,并导出这种自适应律中信号有界的充分条件;证明了δ-修正自适应算法适用于时变系统的模型参考自适应控制,并且控制系统是稳定的。仿真实例表明δ-修正算法是有效的。 相似文献
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针对在随机需求下交货延迟所导致供应链多级库存系统库存积压、缺货和牛鞭效应等问题,建立了基于自适应控制算法的多级库存动态优化模型。通过泰勒展开和拉布拉斯变换建立了基于APIOBPCS策略考虑延迟的动态多级库存控制模型;由Lyapunov渐进稳定性定理设计了一种适用于多级库存的模型参考自适应控制算法,其中以无交货延迟的参考库存模型作为目标,通过调节线性补偿函数和自适应控制率,逐渐缩小实际库存模型与参考库存模型间的输出误差,以此削弱交货延迟对多级库存模型的影响;通过实证数据验证了模型参考自适应控制对一个三级供应链库存系统的动态优化效果。仿真结果表明,自适应控制下的无信息共享多级APIOBPCS库存系统缺货全部归零,牛鞭效应下降40.7%。在不增加企业运营投入的前提下,通过自适应控制算法,优化资源配置,动态削弱了交货延迟对多级库存的影响,提升了供应链运营效率。 相似文献
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研究系统存在不确定性的大柔性飞行器的姿态跟踪控制问题.针对高阶大柔性飞行器模型,使用平衡实现方法对其降阶,并通过奇异值对比分析系统降阶前后特性.基于降阶模型,设计LQR-PI控制器作为基线控制器.考虑不确定性,利用李雅普诺夫稳定性理论设计模型参考自适应控制器,并对比两种方法的控制效果.仿真结果显示,所提方案对包含不确定性的系统具有较好的控制效果,能使系统完成期望的姿态跟踪目标. 相似文献
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近年来,自适应控制领域取得的主要成果是:解决了大范围稳定性问题,弄清了自适应控制各种实现方法之间的等价性。这些发展成果使我们能用统一的方式来研究自适应控制的各种问题。 模型参考自适应控制(MRAC)和自校正调节器(STR)是解决自适应控制问题的两种主要方法。模型参考自适应控制已经被用于连续时间系统和离散时间系统,而自校正调节器仅能用来分析离散时间系统。不过到目前为止,模型参考自适应控制主要只用于确定性系统,而随机自校正调节器则是研究不确定性系统的有效方法。随着这两种方法之间等价性的建立,必将导致模型参考自适应控制和自校正调节器乏间的互相补充和互相促进。 本文的目的是简要地回顾一下近年来自适应控制的发展情况,并为将来的研究指出可能的方向。 相似文献
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欠驱动船舶路径跟踪的神经网络稳定自适应控制 总被引:1,自引:0,他引:1
针对三自由度欠驱动船舶模型参数不确定的路径跟踪问题, 设计了神经网络稳定自适应控制器. 首先应用微分同胚等效变换和Lyapunov直接法设计参考航向和参考速度, 然后对船舶模型参数不确定的操纵环路和推进环路分别设计神经网络稳定自适应控制器跟踪参考航向和参考速度, 并对外界风浪流干扰进行自适应补偿.Lyapunov稳定性分析证明了船舶路径跟踪闭环系统的所有误差信号一致最终有界. 仿真研究验证了神经网络稳定自适应路径跟踪器的有效性. 相似文献
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It is well known that while the perfect model matching condition (i.e. unstable plant zeros must be zeros of the reference model) is not met, the model reference adaptive control cannot easily be implemented. In adaptive control systems, since the plant is assumed to be unknown previously, it is a difficult task to choose an adequate reference model such that the perfect model matching condition is guaranteed in every adaptive step. In this paper, a new design algorithm for model reference adaptive control systems is proposed to synthesize an adaptive controller such that the error between the reference model output and the plant output can vanish in a deadbeat manner. In this situation, the stringent matching condition can be relaxed in every adaptive step, so our design algorithm is also suitable for unstable or non-minimum phase systems. Several simulation results are presented to illustrate the good behaviour of our design algorithm. 相似文献
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对象参考参数自适应时滞补偿器 总被引:2,自引:0,他引:2
基于模型参考自适应控制原理,提出对象参考参数自适应时滞补偿器,以线性大时滞不确定被控对象为参考模型综合出自适应律,使预估补偿器的参灵敏逐步逼近被控对象的参数直至相等,仿真研究表明,在参数不匹配和出现负荷扰动的情况下,参数自适应时滞补偿器均有良好的预估补偿能力。 相似文献
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Model reference adaptive control is a major design method for controlling plants with uncertain parameters. The primary objective of this paper is to develop a new design approach for a differentiator-free model reference adaptive control of a single-input single-output linear time-invariant plant. The proposed method, called the “Identifier-tracking model reference adaptive control”, uses a stacked identifier structure that is new to the field of adaptive control. The goal is to make the output of the plant asymptotically track the output of the first identifier, and then driving the output of the first identifier to track that of the second identifier, and so forth, up to the qth identifier where q is the relative degree of the plant. Lastly, the output of the qth identifier is forced to converge to that of the reference model. Simulation results show the superiority of the proposed method over the traditional model reference adaptive control with augmented error in terms of the transient response. Since the resulting control systems are non-linear and time-varying, the stability analysis of the overall system plays a central role in developing the theory. 相似文献
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C.Richard Johnson 《Automatica》1980,16(4):419-421
The task of discrete model reference adaptive control is manipulated into an output error identification problem. Strictly causal output error identifiers recently developed as adaptive recursive filters are therefore proposed for unique provision of a model reference adaptive control algorithm relying only on input-output data. 相似文献
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Ehsan Arabi 《International journal of control》2013,86(11):2509-2520
One of the fundamental problems in model reference adaptive control design is the ability of the controlled system to achieve not only stability but also a user-defined performance in the presence of exogenous disturbances and system uncertainties. To this end, we recently proposed a set-theoretic model reference adaptive control framework, which guarantees the norm of the system error to be less than a user-defined constant performance bound. The contribution of this paper is to generalise the set-theoretic model reference adaptive control framework for enforcing user-defined time-varying performance bounds on the system error, which gives the control designer a flexibility to control the closed-loop system performance as desired on different time intervals (e.g. transient time interval and steady-state time interval). Two adaptive command following control architectures are proposed and their stability and performance properties are rigorously established using system-theoretic methods. 相似文献
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Helen M. Johnson 《Dynamics and Control》1992,2(4):349-362
A model reference adaptive system (MRAS) is applied to a nonlinear oscillator to achieve adaptive control. Since the model and plant of the system are not linearized to achieve the adaptive laws, the true behavior of the strongly nonlinear system is not lost. By considering important properties of the reference model describing a well-behaved nonlinear oscillator, it is possible to derive the error-equation, which is linear in the state variables. Liapunov synthesis is used to achieve adaptive control, and stability is thus guaranteed. The technique is simulated using an adaptive autopilot for a ship. 相似文献
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Discrete-time deadbeat model reference adaptive control of an adjustable-speed DC motor drive system
WEN SHYONG YU 《International journal of systems science》2013,44(6):1067-1077
An imperfect model reference adaptive control for a DC motor drive system having bounded disturbances is proposed. The discrete-time model reference adaptive control algorithm proposed by Chiang and Chen (1987) with bounded disturbances is introduced to an Elettronica Veneta Mod. IBS-4/EV DC motor. This work shows that the adaptive controller can maintain good performance during startup, anticlockwise, or clockwise winding in the regulating reference signals. 相似文献
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This paper considers the stability problem of the model reference adaptive control systems by means of the properties of hyperstable systems. A theorem concerning the hyperstability of model reference adaptive control systems is presented. This theorem directly gives a structure of the adaption mechanism. The results presented here include all the results obtained by Butchart, Shackcloth, Parks, Winsor, Roy, and Dressler. The hyperstability approach presented in this paper also allows for other solutions to the adaption mechanism and represents a general method for studying this type of adaptive systems. The results are directly applicable to the design of model reference adaptive control systems and they were verified for some particular cases by analogical simulation. 相似文献
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Intelligent systems may be viewed as a framework for solving the problems of nonlinear system control. The intelligence of the system in the nonlinear or changing environment is used to recognize in which environment the system currently resides and to service it appropriately. This paper presents a general methodology of adaptive control based on multiple models in fuzzy form to deal with plants with unknown parameters which depend on known plant variables. We introduce a novel model‐reference fuzzy adaptive control system which is based on the fuzzy basis function expansion. The generality of the proposed algorithm is substantiated by the Stone‐Weierstrass theorem which indicates that any continuous function can be approximated by fuzzy basis function expansion. In the sense of adaptive control this implies the adaptive law with fuzzified adaptive parameters which are obtained using Lyapunov stability criterion. The combination of adaptive control theory based on models obtained by fuzzy basis function expansion results in fuzzy direct model‐reference adaptive control which provides higher adaptation ability than basic adaptive‐control systems. The proposed control algorithm is the extension of direct model‐reference fuzzy adaptive‐control to nonlinear plants. The direct fuzzy adaptive controller directly adjusts the parameter of the fuzzy controller to achieve approximate asymptotic tracking of the model‐reference input. The main advantage of the proposed approach is simplicity together with high performance, and it has been shown that the closed‐loop system using the direct fuzzy adaptive controller is globally stable and the tracking error converges to the residual set which depends on fuzzification properties. The proposed approach can be implemented on a wide range of industrial processes. In the paper the foundation of the proposed algorithm are given and some simulation examples are shown and discussed. © 2002 Wiley Periodicals, Inc. 相似文献