共查询到20条相似文献,搜索用时 15 毫秒
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The problem of designing a stable sliding mode giving robust performance of a variable structure control system is studied. A set of specified eigenvalues is assigned to the closed-loop feedback system during the sliding mode. The design philosophy seeks to build on the known robustness and invariance properties associated with the use of discontinuous (or continuous) non-linear controls, by assigning the eigenvectors associated with the sliding-mode eigenvalues in a manner that leads to a robust control scheme. A previously developed canonical form for the hyperplane design problem is again employed. The design technique centres on a recently published eigenvalue assignment algorithm, and is illustrated by the inclusion of an example. 相似文献
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Han Ho Choi Author Vitae 《Automatica》2009,45(11):2646-2650
Based on the variable structure control (VSC) theory, we develop an adaptive fuzzy control system design method for uncertain Takagi-Sugeno fuzzy models with norm-bounded uncertainties. We relax the restrictive assumptions that each nominal local system model shares the same input channel and the norm bound of the uncertainty is known, which are usually invoked in the traditional VSC-based fuzzy control design methods. As the local controller we use a VSC law with a switching feedback control term and an adaptation law to account for the norm-bounded uncertainties. In terms of LMIs, we derive a sufficient condition for the existence of linear sliding surfaces guaranteeing the asymptotic stability. We present an LMI characterization of such sliding surfaces. We also give an LMI-based design algorithm, together with a numerical design example. 相似文献
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离散时间系统变结构控制的趋近律问题 总被引:15,自引:3,他引:15
针对离散系统变结构控制,提出了两个新的滑模趋近律.应用该趋近设计变结构控制系统,其原点的稳定性和系统的平稳性都优于指数趋近律和比例-等速-变速趋近律.通过仿真例子对此进行了验证. 相似文献
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Two approximation laws of sliding mode for discrete-time variable structure control systems are proposed to overcome the limitations of the exponential approximation law and the variable rate approximation law. By applying the proposed approximation laws of sliding mode to discrete-time variable structure control systems, the stability of origin can be guaranteed, and the chattering along the switching surface caused by discrete-time variable structure control can be restrained effectively. In designing of approximation laws, the problem that the system control input is restricted is also considered, which is very important in practical systems. Finally a simulation example shows the effectiveness of the two approximation laws proposed. 相似文献
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Two approximation laws of sliding mode for discrete-time variable structure control systems are proposed to overcome the limitations of the exponential approximation law and the variable rate approximation law. By applying the proposed approximation laws of sliding mode to discrete-time variable structure control systems, the stability of origin can be guaranteed, and the chattering along the switching surface caused by discrete-time variable structure control can be restrained effectively. In designing of approximation laws, the problem that the system control input is restricted is also considered, which is very important in practical systems. Finally a simulation example shows the effectiveness of the two approximation laws proposed. 相似文献
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一种离散时间系统变结构控制的新方法 总被引:2,自引:0,他引:2
研究离散时间系统变结构控制问题,提出一种新的离散变结构趋近律.利用该趋近律设计的离散变结构控制器,不仅能大幅度削弱抖振,使系统运动最终趋干原点不存在稳态振荡,而且可使系统的准滑动模态保持步步穿越切换面的基本属性,有效地改善了控制品质,提高了系统的鲁棒性.仿真结果验证了该方法的有效性与合理性. 相似文献
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A new approach to control design for large-scale systems using variable structure systems (VSS) theory is presented. Multilevel control concepts arc used to decompose a large control problem into a two-level algorithm such that each subsystem is stabilized with local discontinuous controllers and higher level corrective control is designed to take into account the effect of interactions among the subsystems. Two numerical examples are discussed as illustrations. 相似文献
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G. Bartolini 《Systems & Control Letters》1988,10(2)
A nonlinear control system with uncertain dynamics described by a single ordinary differential equation with scalar control and available state is given. Based on knowledge of upper and lower estimates of the unknown dynamics, we show that the system can be transformed to an asymptotically equivalent linear model (arbitrarily fixed) described by a single linear ordinary differential equation of the same order, by using an (explicitly described) discontinuous feedback control law of variable structure type.The linear behaviour is obtained up to an (arbitrarily fast) exponentially decaying error term. 相似文献
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Design of variable structure control for fuzzy nonlinear systems 总被引:1,自引:0,他引:1
In this paper, the variable structure control problem is presented for Takagi–Sugeno fuzzy systems with uncertainties and external disturbances. The sliding surfaces for the T–S fuzzy system are proposed by using a Lyapunov function and a fuzzy Lyapunov function, respectively. And we design the variable structure controllers such that the global T–S fuzzy system confined on the sliding surfaces is asymptotically stable. Two examples are given to illustrate the effectiveness of our proposed methods. 相似文献
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This note presents a decentralized variable structure control design for a nonlinear state model of two coupled pendulums. This was motivated by the swing equation model of a two-machine power system whose behavior is similar. The control objective is to drive the pendulum motion from one equilibrium point to another. 相似文献
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In this paper, a fuzzy logic controller (FLC) based variable structure control (VSC) with guaranteed stability for multivariable systems is presented. It is aimed at obtaining an improved performance of nonlinear multivariable systems. The main contribution of this work is firstly developing a generic matrix formulation of the FLC-VSC algorithm for nonlinear multivariable systems, with a special attention to non-zero final state. Secondly, ensuring the global stability of the controlled system. The multivariable nonlinear system is represented by T-S fuzzy model. The identification of the T-S model parameters has been improved using the well known weighting parameters approach to optimize local and global approximation and modeling capability of T-S fuzzy model. The main problem encountered is that T-S identification method cannot be applied when the membership functions (MFs) are overlapped by pairs. This in turn restricts the application of the T-S method because this type of membership function has been widely used in control applications. In order to overcome the chattering problem a switching function is added as an additional fuzzy variable and will be introduced in the premise part of the fuzzy rules together with the state variables. A two-link robot system and a mixing thermal system are chosen to evaluate the robustness, effectiveness, accuracy and remarkable performance of proposed FLC-VSC method. 相似文献
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Kar-Keung Young 《Automatic Control, IEEE Transactions on》1977,22(2):279-281
The application of theory of variable structure systems (VSS) in the design of controllers for single input-single output model reference systems is considered. It is shown that the resulting controller has similar structure as those obtained using the second method of Lyapunov except that the states of the model are also used. The error trajectories move towards the switching surface for all values of the error and continues on it as sliding motions. The present approach clarifies the relationship between stability and nonminimum phase zeros of the plant. 相似文献
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In this paper, the problems in sliding mode control systems with constraint control input are described, and then we utilize selecting a switching surface with an integrator to solve this problem and to derive a bound for the existence of sliding motion. Additionally, we propose an adaptive sliding mode controller in order to reduce settling time and also maintain the sliding motion in a larger bound. Finally, an illustrative example is given to demonstrate the effect of proposed controller. 相似文献
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An adaptive variable structure model-following control (AVSMFC) design is proposed for trajectory tracking in a nonlinear robot system which ensures the stability of the intersection of the surfaces without necessarily stabilizing each individual one. The approach avoids the difficulties linked to the strict positive realness requirement in traditional AMFC by taking advantage of the inherent positive definiteness of the manipulator's inertia matrix, and is easily extendible to a higher number of links. The controller does not require any knowledge of a nonlinear robotic system and does not necessarily need the occurrence of a sliding mode at each individually stable discontinuity surface. It thus greatly reduces the complexity of design. In the closed loop, the joint angles asymptotically converge to the reference trajectory with a prescribed transient response. Chattering is eliminated by restricting the state of the system to slide within a boundary layer rather than along the intersection of the surfaces 相似文献
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The theory of variable structure systems is extended to three-segment variable structure systems. This is an effective means to insensitize a system to parameter variations and disturbances. The sliding mode region is extended and the response can start and stay on the sliding mode from the initial to final running time. Examples are given to illustrate the effectiveness of the proposed method. The simulation results show the superiority of the three-segment variable structure systems. 相似文献
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Output tracking control of MIMO fuzzy nonlinear systems using variable structure control approach 总被引:6,自引:0,他引:6
Feng Zheng Qing-Guo Wang Tong Heng Lee 《Fuzzy Systems, IEEE Transactions on》2002,10(6):686-697
The output tracking control problem for nonlinear systems in the presence of both parameter perturbations and external disturbances is studied. Our approach is based on the Takagi-Sugeno (T-S) fuzzy modeling method and a variable structure control (VSC) technique. Therefore, the systems considered are not and need not be in the triangular and parametric strict-feedback form, which are prevalent among adaptive model following control for nonlinear systems, or in the normal form, which pervades almost all existing results in neuro-fuzzy model following control approach. We first study the problem of stabilization of T-S fuzzy systems by using a VSC technique. A method for the design of a switching surface based on linear matrix inequalities is developed and a stabilizing controller based on a reaching law concept in the presence of both parameter perturbations and external disturbances is proposed. Then, the method is extended to design controllers for output tracking of T-S fuzzy nonlinear systems in two cases, i.e. systems which possess the so-called strong passive subsystems and strong stable zero dynamics, respectively. Finally, illustrative examples are presented to demonstrate the whole design procedure from the original nonlinear systems to their fuzzification and finally to the realization of the desired controllers. Simulation results show that the goal of output tracking can be achieved by the proposed controllers. 相似文献
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Chong Lin Qing-Guo Wang Tong Heng Lee 《Fuzzy Systems, IEEE Transactions on》2005,13(6):787-798
In view of a recent new application of variable structure control (VSC) to the stabilization problem for Takagi-Sugeno (T-S) fuzzy models, this paper aims to study the stabilization of uncertain fuzzy time-delay systems in T-S fuzzy model via VSC approach. There are mainly two features in this paper: one lies in the incorporation of time-delays (both smooth and nonsmooth delays) in which case Lyapunov functionals and Razumikhin Theorem are required to solve the stabilization problem; the other feature is that not only matched uncertainties but also mismatched uncertainties in the state variables are considered. As a sequence, the contribution of this paper consists of various control schemes proposed for the VSC design and the present results are in terms of linear matrix inequalities (LMIs). An illustrative example is given to show the effectiveness of our various results. 相似文献