共查询到20条相似文献,搜索用时 15 毫秒
1.
Igor Boiko Author Vitae 《Automatica》2005,41(4):677-683
A frequency-domain method of the input-output analysis of a class of relay feedback systems is proposed. The approach is based on the notion of the locus of a perturbed relay system (LPRS). The proposed LPRS is defined as a characteristic of the response of a linear part to an unequally spaced pulse control of variable frequency in a closed-loop system. Consequently, the LPRS comprises oscillatory and transfer properties of the relay system. Formulas for computing the LPRS are derived. An example of input-output analysis is given. 相似文献
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In this note, the sliding mode control (SMC) is incorporated with time-delay control (TDC) during the sliding phase to reduce the switching gain. TDC identifies the unknown system dynamics and disturbance directly for every time-delay. For a system with a lumped perturbation which is relatively slow varying with respect to the sampling interval, a much low switching gain can be used if a reasonably good estimate of the derivative of system state can be obtained using the past information, hence chattering can be reduced or eliminated while retaining the tracking accuracy. 相似文献
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The delay-dependent H-infinity analysis and H-infinity control problems for continuous time-delay systems are studied. By introducing an equality with some free weighting matrices, an improved criterion of delay-dependent stability with H-infinity performance for such systems is presented, and a criterion of existence and some design methods of
delay-dependent H-infinity controller for such systems are proposed in term of a set of matrix inequalities, which is solved efficiently by an iterative algorithm. Further, the corresponding results for the delay-dependent robust H-infinity analysis and robust H-infinity control problems for continuous time-delay uncertain systems are given. Finally, two numerical examples are given to illustrate the efficiency of the proposed method by comparing with the other existing results. 相似文献
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In this paper the problem of sliding mode control (SMC) with passivity of a class of uncertain nonlinear singular time-delay systems is studied. An integral-type switching surface function is designed by taking the singular matrix into account, thus the resulting sliding mode dynamics is a full-order uncertain singular time-delay system. By introducing some slack matrices, a delay-dependent sufficient condition is proposed in terms of linear matrix inequality (LMI), which guarantees the sliding mode dynamics to be generalized quadratically stable and robustly passive. The passification solvability condition is then established. Moreover, a SMC law and an adaptive SMC law are synthesized to drive the system trajectories onto the predefined switching surface in a finite time. Finally, a numerical example is provided to illustrate the effectiveness of the proposed theory. 相似文献
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同时含有状态和输入时滞系统的滑模控制 总被引:6,自引:0,他引:6
研究同时舍状态和输入时滞的系统交结构控制问题,基于LMI,给出了存在滑动模态的时滞相关的充分条件,利用LMI的解,得到了两种不同的滑动模态和控制器的设计方法,所提出的方法简单量行,具有较小的保守性,可进一步推广到多时滞和不确定时滞系统。 相似文献
8.
Lisong Yuan 《Systems & Control Letters》1996,28(5):281-289
The problems of robust analysis and synthesis of systems with state-delay and norm-bounded time-varying parameter uncertainty are studied. It is shown that these problems are equivalent to the H∞ analysis and synthesis problems of an auxiliary system, which is independent of the time-delay and the uncertainty in the system. The necessary and sufficient conditions for the equivalence are developed. Thus any standard H∞ analysis and synthesis method can be used to solve this problem. 相似文献
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In this paper, a procedure for construction of quadratic Lyapunov-Krasovskii functionals for linear time-delay systems is proposed. It is shown that these functionals admit a quadratic low bound. The functionals are used to derive robust stability conditions. 相似文献
10.
M. Boutayeb 《Systems & Control Letters》2001,44(2)
In this contribution we propose a simple and useful approach to design observers for discrete-time systems with delays in the state and output variables. The main feature is that the necessary and sufficient conditions for the existence of such observer are derived. The stability analysis is performed by the Lyapunov approach, where the obtained conditions are expressed in terms of a modified Riccati equation. Numerical examples are provided to show efficiency of the proposed observer. 相似文献
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In the previous papers, the stability of PID-controlled first-order time-delay systems has been investigated by means of several methods, of which the Nyquist criterion, a generalization of the Hermite–Biehler Theorem, and the root location method are well known. Explicit expressions of the boundaries of the stability region, which is the set of controller parameters that give stable closed-loop systems, have been determined. From these studies, one can verify that not all plants can be made stable and then obtain the set of process parameters that allow stable closed-loop systems. With this set, one can implement the stability region of the process parameters. In a recent paper the stability conditions based on Pontryagin’s studies and valid for arbitrary-order plants have been presented. The procedure deduced for the controller parameters is exhaustive, but that deduced for the process parameters requires further mathematical evaluations, whose complexity is proportional to the number of process time constants. In the aforementioned recent paper these evaluations have been performed for a second-order time-delay plant whose transfer function has no zero. The aim of this paper is to execute these calculations for a second-order plant whose transfer function has one zero and to provide the related stability region. 相似文献
12.
研究线性时滞系统最优控制的前馈反馈近似设计问题.基于Taylor级数法,将系统的二次型最优控制问题转化为线性代数方程组的求解问题,给出了系统前馈反馈次优控制律的存在唯一性条件和Taylor级数表示形式.仿真算例验证了方法的有效性. 相似文献
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An adaptive online parameter identification is proposed for linear single-input-single-output (SISO) time-delay systems to simultaneously estimate the unknown time-delay and other parameters. After representing the system as a parameterized form, a novel adaptive law is developed, which is driven by appropriate parameter estimation error information. Consequently, the identification error convergence can be proved under the conventional persistent excitation (PE) condition, which can be online tested in this paper. A finite-time (FT) identification scheme is further studied by incorporating the sliding mode scheme into the adaptation to achieve FT error convergence. The previously imposed constraint on the system relative degree is removed and the derivatives of the input and output are not required. Comparative simulation examples are provided to demonstrate the validity and efficacy of the proposed algorithms. 相似文献
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This paper investigates the feedback stabilization problem for SISO linear uncertain control systems with saturating quantized measurements. In the fixed quantization sensitivity framework, we propose a time varying control law able to effectively account for the presence of saturation, which is often the main source of instability, designed using sliding mode techniques. Such controller is proved able to stabilize the plant both in the presence and in the absence of quantization. 相似文献
15.
Chong LinQing-Guo Wang 《Automatica》2002,38(1):177-180
This note deals with the uniqueness of solutions to relay feedback systems, and presents an improved criterion over that in Lootsma et al. (Automatica 35(3) (1999) 467). 相似文献
16.
Finite-time stability and stabilization of time-delay systems 总被引:2,自引:0,他引:2
Emmanuel Moulay Michel Dambrine Nima Yeganefar Wilfrid Perruquetti 《Systems & Control Letters》2008,57(7):561-566
Finite-time stability and stabilization of retarded-type functional differential equations are developed. First, a theoretical result on finite-time stability inspired by the theory of differential equations, using Lyapunov functionals, is given. As it may appear not easily usable in practice, we show how to obtain finite-time stabilization of linear systems with delays in the input by using an extension of Artstein’s model reduction to nonlinear feedback. With this approach, we give an explicit finite-time controller for scalar linear systems and for the chain of integrators with delays in the input. 相似文献
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Si-Lu Chen Kok Kiong Tan Sunan Huang 《International journal of systems science》2013,44(12):1229-1239
This article investigates the limit cycles within type-1 linear systems under PID-type of relay feedback. The problem is generalised from the identification of friction models of servo mechanical systems via limit-cycle experiments under dual-channel relay feedback. Locations of limit cycles are given so that the exact durations between two consecutive switchings of relays can be determined via numerical computation. After this, local stability of limit cycles can be checked via the Jacobian of Poincaré map. Examples are analysed using proposed theorems. 相似文献
19.
A general receding horizon control (RHC), or model predictive control (MPC), for time-delay systems is proposed. The proposed RHC is obtained by minimizing a new cost function that includes two terminal weighting terms, which are closely related to the closed-loop stability. The general solution of the proposed RHC is derived using the generalized Riccati method. Furthermore, an explicit solution is obtained for the case where the horizon length is less than or equal to the delay size. A linear matrix inequality (LMI) condition on the terminal weighting matrices is proposed, under which the optimal cost is guaranteed to be monotonically non-increasing. It is shown that the monotonic condition of the optimal cost guarantees closed-loop stability of the RHC. Simulations demonstrate that the proposed RHC effectively stabilizes time-delay systems. 相似文献
20.
带有乘性噪声的线性时滞系统固定步长平滑估计 总被引:1,自引:0,他引:1
研究带有乘性噪声的线性时滞系统的固定步长平滑估计问题.通过虚拟噪声补偿技术,将该问题转化为一类带有未知时变噪声的随机系统的估计问题;基于等价系统的新息重组分析及投影定理,通过求解与原系统同维的Riccati方程,得到系统的最优平滑估计器.该方法无需扩维,具有较大的计算优势.仿真实验表明了该算法的有效性. 相似文献