一类弹性飞行器动态特性的摄动估计

本文针对一类高速、细长体飞行器的动力学模型,应用矩阵谱的摄动与估计理论,分析了气动力非定常因素对飞行器动态特性的影响。结论表明,利用低阶的准定常系统结果可以十分准确地估计非定常系统特性,从而大大降低动力学方程的阶次,为弹性飞行器的降阶模型研究提供了理论依据,有助于飞行器主动控制系统的分析与设计。     

Dynamic Simulation of Planar Flexible Link Manipulators using Adaptive Modal Integration

In this paper a modal integration method is proposed for analyzingthe dynamic behavior of multi-link planar flexible manipulators. Anon-linear finite element method is employed to derive theequations of motion in terms of a mixed set of generalizedcoordinates of the manipulator with rigid links and deformationparameters that characterize flexible deformations of the links.Using a perturbation method the vibrational motion of themanipulator is modeled as a first-order perturbation of thenon-linear nominal rigid link motion. For that purpose theflexible dynamic manipulator model is split into two parts. Arigidified model describes the nominal rigid link motion. Alinear system linearized about the nominal trajectory describesthe vibrational motion. In order to reduce the dimension of thelinearized system, a modal reduction technique is proposed. Thenmodal integration can be applied using only a small number of lowfrequency modes. The mode-acceleration concept is used to accountfor the pseudo static contribution of the high frequency modes.Applied to the motion of a manipulator mechanism the method isreferred to as adaptive modal integration since thetime-varying nature of the mode shape functions is taken intoaccount.A flexible two-link manipulator is analyzed to illustrate theperformance of the solution method. Comparisons between solutionsutilizing non-linear and perturbation analyzes with and withoutmodal integration show a good agreement. In a simulation with onlya few modes the accuracy is kept, whereas the computation time isdrastically reduced.     

A Mathematical Approach in the Design of Arterial Bypass Using Unsteady Stokes Equations

In this paper we present an approach for the study of Aorto-Coronaric bypass anastomoses configurations using unsteady Stokes equations. The theory of optimal control based on adjoint formulation is applied in order to optimize the shape of the zone of the incoming branch of the bypass (the toe) into the coronary according to several optimality criteria.Dedicated to David Gottlieb on the occasion of his 60th birthdayValery Agoshkov: This work has been prepared when the first author was a visiting professor at Institut d’Analyse et Calcul Scientifique of the école Polytechnique Fédérale de Lausanne     

确定性扰动PV插值算法及其性能分析

This paper discusses the performance of some existing interpolation algorithms, and presents a deterministic perturbation partial volume interpolation algorithm. This algorithm distributes the contribution of intensity of the transformed point to nine entries in the joint histogram,imports and determines the perturbation to calculate the weights. Then it is analyzed and compared with other algorithms. The results of experiments indicate that this algorithm can avoid the local extremes on grid points and non-grid points, and effectively smooth the object function.     

一个带扩散扰动的风险模型的破产概率

在经典的Lundberg-Cramer的风险模型的基础上，将保险单的签署过程假定为常数速率Pois—son过程受标准维纳扰动后的保单的签署过程，推广了经典的Lundberg-Cramer的风险模型，获得了带扩散扰动的风险模型的破产概率及其上界，同时给出了调节系数的一个上界，最后讨论了破产概率与扰动强度之间的关系。     

The persistence of nonoscillatory solutions of difference equations under impulsive perturbations

We obtain a sufficient condition for the persistence of nonoscillatory solutions of the difference equation with continuous variable, ,under the impulsive perturbations, x(t_k+τ)−x(t_k)=I_k(x(t_k)),kN(1),     

Analysis of stability of stochastic dynamic systems under Poisson perturbations. II. Stability of solutions in quadratic mean of systems of linear stochastic differential equations under Poisson perturbations

Necessary and sufficient conditions of asymptotic stability in quadratic mean are obtained for trivial solutions of systems of linear stochastic differential equations under Poisson perturbations. Model problems are analyzed. Part I of this article is published in No. 4 (2005). __________ Translated from Kibernetika i Sistemnyi Analiz, No. 6, pp. 50–66, November–December 2005.     

基于阻力估计器的直线伺服系统滑模控制

针对直接驱动的永磁直线同步电动机（PMLSM）伺服系统的端部效应引起的推力波动问题，设计一种带有阻力估计器的滑模变结构速度控制器，滑模控制对扰动和系统参数变化具有很强的鲁棒性，但是却存在抖振现象，影响伺服系统的稳态性能，为了削弱滑模控制的抖振，设计一个阻力扰动估计器对阻力扰动（包括直线电机特有的端部效应产生的推力波动）进行估计和补偿。仿真结果表明，该方案对系统参数变化和阻力扰动具有很强的鲁棒性，同时提高了系统的稳态精度。     

一类不确定性系统的鲁棒正实性分析与综合

考虑一类具有多项式型不确定性系统的鲁棒正实性分析和综合问题。这类不确定模型是区间摄动和范数有界摄动系统的自然推广。给出了一个系统具有鲁棒扩展严格正实性 (ESPR)的充分条件 ,利用该条件可估计出使系统保持 ESPR的最大参数摄动范围。在 ESPR分析的基础上 ,进一步给出了ESPR控制器的存在条件和控制器的构造方法。通过凸优化算法 ,得到了所提出方法意义下具有最大摄动界的 ESPR控制器设计方法。     

调试器对并行程序干扰特性的研究

机群系统中并行程序的执行具有不确定性，这种不确定性给并行程序的调试带来了困难，并行程序的不确定性是由运行环境中的各种干扰因素造成的，该文研究交互式调试行为对调试程序的干扰特性，文中给出了算法可以在调试的过程中实时地报告出本次交互式调试操作是否对调试的程序造成了干扰。