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In this article, the stabilization problem is investigated for dynamic nonholonomic systems with unknown inertia parameters and disturbances. First, to facilitate control system design, the nonholonomic kinematic subsystem is transformed into a skew‐symmetric form and the properties of the overall systems are discussed. Then, a robust adaptive controller is presented in which adaptive control techniques are used to compensate for the parametric uncertainties and sliding mode control is used to suppress the bounded disturbances. The controller guarantees the outputs of the dynamic subsystem (the inputs to the kinematic subsystem) to track some bounded auxiliary signals which subsequently drive the kinematic subsystem to the origin. In addition, it can also be shown all the signals in the closed loop are bounded. Simulation studies on the control of a unicycle wheeled mobile robot are used to show the effectiveness of the proposed scheme. © 2001 John Wiley & Sons, Inc. 相似文献
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Continuous casting processes can suffer from a disturbance effect, called “dynamic bulging”, that causes large oscillations of the mold level, significantly reduces the quality of the final product and may cause instability and damages. In this paper this effect is analyzed and a new integrated control strategy is presented capable of significantly reduce the dynamic bulging without slowing down the process. The strategy is based on the superposition of two effects, one derived from the prediction of the periodic components of the oscillations and the second based on a robust adaptation scheme. Simulation and experimental results underline the advantages of the proposed method. 相似文献
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针对一类带时滞状态扰动的系统,讨论了系统的鲁棒自适应镇定问题.当扰动有界且界未知时,运用自适应控制方法,设计出一类自适应控制器.采用Lyapunov_Karasovskii函数方法,证明了文中所提出的控制器可鲁棒镇定该系统. 相似文献
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Dear editor,
The study of nonlinear time-delay systems made great progress in the past few decades[1]and some effective meth-ods were presented for special syst... 相似文献
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B. Martensson (1985) showed that in order to stabilize an unknown linear, time-invariant, finite-dimensional system, it is sufficient to know the order of any stabilizing controller. This result is generalized to a large class of infinite-dimensional systems. For high-gain stabilizable infinite-dimensional systems, an algorithm is presented which takes this additional a priori knowledge into account. Simulation results are presented 相似文献
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A simple discrete adaptive control scheme is proposed for stabilizing minimum phase continuous time systems under fast sampling. Even though the sampled system is not necessarily minimum phase, information about the pole-zero locations of the sampled system can be incorporated to complete the proof of stability. 相似文献
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Young Soo Moon Poogyeon Park Wook Hyun Kwon Young Sam Lee 《International journal of control》2013,86(14):1447-1455
This paper concerns a problem of robust stabilization of uncertain state-delayed systems. A new delay-dependent stabilization condition using a memoryless controller is formulated in terms of matrix inequalities. An algorithm involving convex optimization is proposed to design a controller guaranteeing a suboptimal maximal delay such that the system can be stabilized for all admissible uncertainties. 相似文献
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Global robust stabilization of nonlinear cascaded systems is a challenging problem when the zero-dynamics is not exponentially stable. Recently, some recursive procedure has been developed for handling this problem utilizing the small gain theorem. However, the success of the procedure depends on the satisfaction of some conditions which arise at each step of the recursion. In this paper, we will show that, for the important class of cascaded polynomial systems, the solvability conditions can be made satisfied by appropriately implementing the recursive procedure. This result leads to an explicit construction of the control law. 相似文献
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Kang Hao-Bo Wang Jian-Hui 《International Journal of Control, Automation and Systems》2015,13(3):733-741
International Journal of Control, Automation and Systems - This paper deals with the problem of robust output feedback control for a class of 5DOF upper-limb exoskeleton robot. It is able to assist... 相似文献
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E. P. Ryan 《国际强度与非线性控制杂志
》1993,3(2):169-181
》1993,3(2):169-181
Universal stabilizers are presented for two classes of nonlinear systems, linear in their multiple control inputs: (I) a class of pth order controlled differential inclusions on R″ with full state available for feedback, and (II) a class of nonlinearly perturbed linear systems with restricted state availability. The stabilizers are of a discontinuous feedback form (embedded in a set-valued map), and incorporate adaptive matrix-valued gain functions which exploit the existence of finite spectrum-unmixing sets associated with the systems under consideration. The analysis draws on an extension, to differential inclusions, of LaSalle's invariance principle for ordinary differential equations. 相似文献
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This paper investigates the finite‐time robust simultaneous stabilization problem of a set of nonlinear time‐delay systems with general forms and proposes some new simultaneous stabilization results. First, by developing an equivalent form and applying augmented technique, this paper obtains an augmented equivalent form of the original systems. Secondly, based on the equivalent form, we study finite‐time simultaneous stabilization problem and present some new stabilization results by constructing some suitable Lyapunov functionals. Thirdly, using the simultaneous stabilization results obtained, this paper investigates the finite‐time robust simultaneous stabilization problem for the set systems and proposes a delay‐dependent robust simultaneous stabilization result. Finally, the study of an illustrative example shows that the results obtained by this paper work well in the finite‐time robust simultaneous stabilization the set systems. It is shown that, by using the method in this paper, the developed conditions do not contain delay terms, which can avoid solving nonlinear mixed matrix inequalities and reduce effectively computational burden in studying nonlinear time‐delay systems. 相似文献
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Bertina Ho-Mock-Qai 《Systems & Control Letters》2002,45(5):331-338
We show that given any family of asymptotically stabilizable LTI systems depending continuously on a parameter that lies in some subset [a1,b1]××[ap,bp] of
, there exists a C0 time-varying state feedback law v(t,x) (resp. a C0 time-invariant feedback law v(x)) which robustly globally exponentially stabilizes (resp. which robustly stabilizes, not asymptotically) the family. Further, if these systems are obtained by linearizing some nonlinear systems, then v(t,x) locally exponentially stabilizes these nonlinear systems. Finally, v(t,x) globally exponentially stabilizes any time-varying system which switches “slowly enough” between the given LTI systems. 相似文献
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This paper studies the global robust stabilization problem for a class of feedforward systems that is subject to both dynamic and time-varying static uncertainties. A small gain theorem-based bottom-up recursive design is developed for constructing a nested saturation control law. At each recursion, two versions of small gain theorem with restrictions are employed to establish the global attractiveness and local stability of the closed-loop system at the equilibrium point, respectively. 相似文献
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为带有参数不确定性的T-S模糊控制系统提出了新的基于观测器的鲁棒输出镇定条件. 该条件用来设计模糊控制器和模糊观测器. 为了设计模糊控制器和模糊观测器, 用T-S模糊模型来表示非线性系统, 并运用平行分布补偿观念. 充分条件基于二次Lyapunov函数, 通过将模糊系统的鲁棒镇定条件表述为一系列矩阵不等式, 比以往文献中列出的条件具有更小的保守性. 该不等式为双线性矩阵不等式, 可分两步骤先后解得使T-S模糊系统镇定的控制器增益和观测器增益. 最后, 通过对一个具有不确定性的连续时间非线性系统控制的例子证明了提出方法比以往方法更宽松. 相似文献
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S. Q. ZHU 《International journal of control》2013,86(6):1429-1440
The largest robust stability radius γ(P0) of a system P0 is defined as the radius of the largest ball Bmax in the gap metric centred at P0 which can be stabilized by one single controller. Any controller stabilizing Bmax is called an optimally robust controller of P0 . A controller, regarded as a system, should have its own largest robust stability radius also. In this note it is first shown that the largest robust stability radius of any optimally robust controller of P0 is larger than or equal to γ(Po)- The main result of this paper is the estimate of the variations (in the L∞-norm) of the closed-loop transfer matrix caused by the perturbations of the system or of the optimally robust controller. Finally, the schemes of designing finite-dimensional controllers are presented via the largest robust stability radius. These schemes guarantee that the designed finite-dimensional controllers will stabilize the original infinite-dimensional systems. Moreover, the closed-loop transfer matrices can be estimated. 相似文献
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Hansheng Wu 《Automatic Control, IEEE Transactions on》2004,49(4):611-616
The problem of robust tracking and model following is considered for a class of linear systems with multiple delayed state perturbations, time-varying uncertain parameters, and disturbance. In this note, it is assumed that the upper bounds of the delayed state perturbations, uncertainties, and external disturbances, are unknown. An improved adaptation law with /spl sigma/-modification is proposed to estimate such unknown bounds, and on the basis of the updated values of these unknown bounds, a class of continuous memoryless state feedback controllers is constructed for robust tracking of dynamical signals. The proposed adaptive robust tracking controller can guarantee that the tracking error decreases asymptotically to zero in the presence of multiple delayed state perturbations, time-varying uncertain parameters, and disturbance. In addition, it is also shown that this improved adaptation law with /spl sigma/-modification can be applied to the general adaptive control problems to obtain some more exact control results. Finally, a numerical example is given to demonstrate the validity of the results. 相似文献