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1.
KE Hai-sen YE Xu-dong 《浙江大学学报(A卷英文版)》2006,7(10):1742-1747
INTRODUCTION In recent years, much progress has been made in the design of control laws for systems subjected to nonholonomic constraint making it impossible to stabilize the system by any time-invariant continuous state feedback control law. This fact stimulates re- searchers to construct time-varying (Jiang and Ni- jmeijer, 1999; Jiang, 2001; Samson, 1995; Tian and Li, 2002) or discontinuous (Chang and Chen, 2002; Ge et al., 2003; Hu et al., 2004; Kim and Tsiotras, 2002; Mnif, 2004;… 相似文献
2.
用模式识别的理论和方法，对内燃机气门间隙的识别问题进行了探讨。在分析气门振动力学模型的基础上，通过测取振动信号获得故障特征信息，用模式识别的理论和方法，在建立状态特征模式空间的基础上实现对故障的分类识别。考虑到内燃机振动信号的复杂性，采用了外触发采样和有效截取的方法进行信号的数据采集和分析。 相似文献
3.
Delay-dependent robust control for uncertain discrete singular systems with time-varying delay 总被引：1，自引：0，他引：1
The design problem of delay-dependent robust control For uncertain discrete singular systems with time-varying delay is addressed in this paper. The uncertainty is assumed to be norm-bounded. By establishing a finite sum inequality based on quadratic terms, a new delay-dependent robust stability condition is derived and expressed in terms of linear matrix inequalities （LMIs）. A suitable robust state feedback control law is presented, which guarantees that the resultant closed-loop system is regular, causal and stable for all admissible uncertainties. Numerical examples are given to demonstrate the applicability of the proposed method. 相似文献
4.
Input-output approach to robust stability and stabilization for uncertain singular systems with time-varying discrete and distributed delays 总被引：3，自引：0，他引：3
Based on input-output approach, the robust stability and stabilization problems for uncertain singular systemswith time-varying delays are investigated. The parameter uncertainties are assumed to be norm-bounded and the time-varying delays include both discrete delay and distributed delay. By introducing a new input-output model, the time-delay system is embedded in a family of systems with a forward system without time delay and a dynamical feedback uncertainty. A sufficient and necessary condition, which guarantees the system regular, impulse-free and stable for all admissible uncertainties, is obtained. Based on the strict linear matrix inequality, the desired robust state feedback controller is also obtained. Finally, a numerical example is provided to demonstrate the application of the proposed method. 相似文献
5.
为了开展液压元件溢流阀实验课教学,设计并搭建了可视化溢流阀振动测试实验平台。该实验平台不仅可以直观反映溢流阀工作中阀芯的运动变化过程,并且实时输出阀芯运动变化曲线。研究液压阀的失稳机理和颤振行为,同时对阀体关键部位采用透明设计,可以方便在线观察阀芯的振动过程。加装合适传感器便于研究不同结构、不同参数对溢流阀振动影响,为研究溢流阀工作失稳机理和阀颤振行为提供参考。 相似文献
6.
Adam Czornik 《Journal of The Franklin Institute》2010,347(2):502-507
In this paper we introduce certain constants that characterize exponential stability or exponential unstability of discrete linear time varying systems. We also present bounds for Lyapunov and Perron exponents in terms of the introduced constants. 相似文献
7.
Ross H. Sanders 《Journal of sports sciences》2013,31(2):213-227
Abstract The purpose of this study was to establish the characteristics of the movement patterns common to flutter kicking of skilled swimmers and to determine how the movement patterns of swimmers at different levels of a “learn-to-swim” programme differ from those of skilled swimmers. Also, the nature of the skill afforded the opportunity to investigate learning of a cyclical multi-joint task from a motor control perspective. The underwater motion of nine children representing three levels of a “learn-to-swim” programme and 10 skilled swimmers were video-recorded while performing nine cycles of prone flutter kicking. Kinematics including joint angular motion and coordination of joint actions were calculated. Fourier analysis was applied to determine the frequency composition of the vertical undulations of the hip, knee, and ankle and to calculate the velocity of the body wave travelling caudally from hip to ankle. Fourier analysis also enabled investigation of biological noise, as distinct from variability. The results indicated the desired joint angles and coordination towards which learners could be guided. An index based on the ratio of hip – knee and knee – ankle body wave velocities showed that the inter-joint coordination of most learners was not appropriate for effective flutter kicking. There was strong evidence to suggest that skilled performance in flutter kicking is characterized by sequencing of joint actions to produce a single sinusoidal body wave moving caudally with not decreasing and preferably increasing velocity, low biological noise, and small variability. 相似文献
8.
ＩＮＴＲＯＤＵＣＴＩＯＮＩｔｈａｓｂｅｅｎｒｅｃｏｇｎｉｚｅｄｔｈａｔｌｏｎｇ ｓｐａｎｂｒｉｄｇ ｅｓ ,ｃａｂｌｅ ｓｕｐｐｏｒｔｅｄｂｒｉｄｇｅｓｉｎｐａｒｔｉｃｕｌａｒ,ａｒｅｓｕｂｊｅｃｔｔｏｔｈｅｄｙｎａｍｉｃｗｉｎｄａｃｔｉｏｎ .Ｔｈｅａｅｒｏｄｙ ｎａｍｉｃｓｔａｂｉｌｉｔｙ (ｆｌｕｔｔｅｒ)ｏｆｓｕｓｐｅｎｓｉｏｎｂｒｉｄｇｅｓｄｕｒｉｎｇｅｒｅｃｔｉｏｎｉｓａｓｕｂｊｅｃｔｏｆｍａｊｏｒｃｏｎｃｅｒｎｆｏｒｒｅｓｅａｒｃｈｅｒｓａｎｄｅｎｇｉｎｅｅｒｓ .Ａｌｔｈｏｕｇｈｔｈｅｐｅｒｉ… 相似文献
9.
Pin-Lin Liu 《Journal of The Franklin Institute》2009,346(10):958-968
This paper investigates the exponential stability problem for uncertain time-varying delay systems. Based on the Lyapunov-Krasovskii functional method, delay-dependent stability criteria have been derived in terms of a matrix inequality (LMI) which can be easily solved using efficient convex optimization algorithms. These results are shown to be less conservative than those reported in the literature. Four numerical examples are proposed to illustrate the effectiveness of our results. 相似文献
10.
将脉动风速及其非线性项引入到桥梁的自激力公式中 ,运用随机微积分理论与矩方程理论 ,得到双方向运动的桥梁断面的一阶矩与二阶矩的微分方程组。通过微分方程的数值方法 ,得到扭转驱动的桥梁断面随机振动的时程曲线 ,从而得到随机失稳的临界风速。研究表明 ,脉动风速非线性项使得扭转驱动的桥梁趋于稳定 相似文献