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101.
The approximate solution of a system for variational inequality with different mapping in Hilbert spaces has been studied, based on the convergence of projection methods. However, little research has been done in Banach space. The primary reason is that projection mapping lacks preferable properties in Banach space. In this paper, we introduce generalized projection methods. By using these methods, the results presented in this paper have extended the main results of Chang et al.’s and Huang and Noor’s recent works [S.S. Chang, H.W. Joseph Lee, C.K. Chan, Generalized system for relaxed cocoercive variational inequalities in Hilbert spaces, Appl. Math. Lett. 20 (2007) 329–334; Zhenyu Huang, Muhammad Aslam Noor, An explicit projection method for a system of nonlinear variational inequalities with different (γ,r)-cocoercive mappings, Appl. Math. Comput. 190 (2007) 356–361] from Hilbert spaces to Banach space. 相似文献
102.
In this paper we concerned with PID controllers for rigid robots whose integral term is driven by a saturation function. We introduce a new tuning procedure with particular conditions that have to be satisfied at each joint. We found that this novel approach relaxes Tomei's condition on the proportional gains which also relaxes conditions on integral gains. We show, through simulations, that important performance improvement is achieved with respect to previous tuning procedures. Copyright © 2010 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society 相似文献
103.
光学相关识别过程中,为减小输入场景中背景噪音对输出相关点的影响,通过分析背景噪音和目标图像的傅里叶谱,在匹配滤波函数中引入一由背景噪音傅里叶谱确定的指数函数,通过指数函数对匹配滤波函数振幅进行非线性调制,使设计的指数型空间匹配滤波器对背景噪音谱透过率小于目标图像谱透过率,从而增加输出相关平面上的信噪比,以实现相关点的正确探测。模拟结果表明当参量m由0增加到1.2时,相关峰值下降2.28倍,信噪比增加3倍。模拟和实验结果均表明:与纯相位匹配滤波器相比其抗噪能力得到明显改善。 相似文献
104.
Jawad Arif Suhail Akhtar 《International Journal of Adaptive Control and Signal Processing》2010,24(4):275-286
Adaptive interference cancelation is of vital importance in a broad array of scientific and engineering disciplines. In this paper we develop a closed‐loop discrete‐time interference cancelation algorithm. The novel features of this algorithm are its ability to deal with multiple channels being affected by interferences with different frequency spectrums. Also we provide a proof of Lyapunov stability of closed‐loop system and asymptotically perfect interference cancelation for a class of interference signals. Furthermore, we introduce a new approach for updating the estimator through the use of staggered estimate. The goal of staggered estimation is to minimize the total number of estimates/calculations done within a time period while ensuring that there is no estimator aliasing. Finally, the proposed algorithm is implemented on an TMS320C6713 DSP Kit and an experimental verification is obtained. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
105.
The asymptotic Lyapunov stability of one quasi-integrable Hamiltonian system with time-delayed feedback control is studied by using Lyapunov functions and stochastic averaging method.First,a quasi-integrable Hamiltonian system with time-delayed feedback control subjected to Gaussian white noise excitation is approximated by a quasi-integrable Hamiltonian system without time delay.Then,stochastic averaging method for quasi-integrable Hamiltonian system is used to reduce the dimension of the original system,a... 相似文献
106.
Abdellah Benzaouia Abdelaziz Hmamed Ahmed EL Hajjaji 《International Journal of Adaptive Control and Signal Processing》2010,24(12):1091-1106
This paper deals with sufficient conditions of asymptotic stability and stabilization for nonlinear discrete‐time systems represented by a Takagi–Sugeno‐type fuzzy model whose state variables take only nonnegative values at all times t for any nonnegative initial state. This class of systems is called positive systems. The conditions of stabilizability are obtained with state feedback control. This work is based on multiple Lyapunov functions. The results are presented in linear matrix inequalities form. A real plant is studied to illustrate this technique. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
107.
V. Karthik K. LahaP. Parameswaran K.S. ChandravathiK.V. Kasiviswanathan T. JayakumarBaldev Raj 《International Journal of Pressure Vessels and Piping》2011
Modified 9Cr-1Mo ferritic steel (P91) is subjected to a series of heat treatments consisting of soaking for 5 min at the selected temperatures in the range 973 K–1623 K (below Ac1 to above Ac4) followed by oil quenching and tempering at 1033 K for 1 h to obtain different microstructural conditions. The tensile properties of the different microstructural conditions are evaluated from small volumes of material by shear punch test technique. A new methodology for evaluating yield strength, ultimate tensile strength and strain hardening exponent from shear punch test by using correlation equations without employing empirical constants is presented and validated. The changes in the tensile properties are related to the microstructural changes of the steel investigated by electron microscopic studies. The steel exhibits minimum strength and hardness when soaked between Ac1 and Ac3 (intercritical range) temperatures due to the replacement of original lath martensitic structure with subgrains. The finer martensitic microstructure produced in the steel after soaking at temperatures above Ac3 leads to a monotonic increase in hardness and strength with decreasing strain hardening exponent. For soaking temperatures above Ac4, the hardness and strength of the steel increases marginally due to the formation of soft δ ferrite. 相似文献
108.
Xiaopeng Wei Dongsheng Zhou Qiang Zhang 《Computers & Mathematics with Applications》2009,57(11-12):1938
In this paper, we obtain some sufficient conditions for determining the asymptotic stability of discrete-time non-autonomous delayed Hopfield neural networks by utilizing the Lyapunov functional method. An example is given to show the validity of the results. 相似文献
109.
NONLINEAR OPTIMAL CONTROL: A CONTROL LYAPUNOV FUNCTION AND RECEDING HORIZON PERSPECTIVE 总被引:1,自引:0,他引:1
Two well known approaches to nonlinear control involve the use of control Lyapunov functions (CLFs) and receding horizon control (RHC), also known as model predictive control (MPC). The on-line Euler-Lagrange computation of receding horizon control is naturally viewed in terms of optimal control, whereas researchers in CLF methods have emphasized such notions as inverse optimality. We focus on a CLF variation of Sontag's formula, which also results from a special choice of parameters in the so-called pointwise minnorm formulation. Viewed this way, CLF methods have direct connections with the Hamilton-Jacobi-Bellman formulation of optimal control. A single example is used to illustrate the various limitations of each approach. Finally, we contrast the CLF and receding horizon points of view, arguing that their strengths are complementary and suggestive of new ideas and opportunities for control design. The presentation is tutorial, emphasizing concepts and connections over details and technicalities. 相似文献
110.
In this paper equivalent conditions for exact observability of diagonal systems with a finite-dimensional output operator are given. One of these equivalent conditions is the conjecture of Russell and Weiss (SIAM J. Control Opt. 32(1) (1994) 1–23). The other conditions are in terms of the eigenvalues and the Lyapunov solutions of finite-dimensional subsystems. 相似文献