非线性单自由度振动系统物理参数的两种辨识方法

本文讨论两种辨识非一单自由度振动系统物理参数的方法，基于描述函数概念的特参数法和由系统时域输入输出信息辨识系统参数的直接时域法。将这两种方法应用于几类非线性背地里自由度振动系统物理参数辨识，并进行了计算机仿真及直接时域法的实验。结果证明了这两种方法的有效性，还提出了对等 参数法的一种改进措施，将 成会考虑在内，以提高辨识精度。     

一种小型静电陀螺仪三位一体系统方案

在比较了国外两种小型静电陀螺仪方案的基础上，研究了一种小型静电陀螺仪质量不平衡调制信号读取、数字式支承和电场恒速三位一体工作系统方案。介绍了三位一体系统的工作原理，讨论了系统各组成模块的功能，对制约系统性能的关键因素作了相关分析。分析表明，在抵消变压器线圈阻抗匹配的条件下，可以忽略加力和信号读取之间的相互影响。     

位移浅水内孤立波

研究两层浅水系统中的内孤立波，该系统由两层常密度不可压缩无黏性水组成。利用Lagrange坐标和Hamilton原理，推导了两层浅水系统的位移浅水内波方程，并进一步导出了两层浅水系统的位移内孤立波解。数值实验表明，位移内孤立波与经典的KdV内孤立波吻合很好，说明Lagrange坐标和Hamilton方法适用于内波分析，可以为构造内波分析的保辛方法提供一种途径。     

挠性陀螺捷联系统场地快速标定

本文给出了捷联式惯性导航系统一种简单实用的场地标定方法。在系统中，对挠性陀螺仪采用特殊安装，把组合件旋转１８０°，用两位置数据测出陀螺的标度系数、常值漂移、加速度计零位和系统真方位。在标定过程中不需要对惯性组合件做水平调整。     

舰船惯性导航系统的双重信息导航工作方式

—舰船惯性导航系统通过不同的机械编排实现不同的导航工作方式，它们各有不同的误差方程和特点，以适应不同的条件。传统的设计方法在具体条件下只实现一种工作方式，保持一种方式的导航信息。本文论述了舰船惯性导航系统中首次应用的双重信息导航工作方式，以这种方式工作的惯性导航系统可在一套物理系统中同时生成，并保持水平阻尼与罗经回路两种工作方式的导航信息。文中分析了该工作方式的原理和特点，并对试验结果和应用情况做了有限说明。     

一类刚-梁耦合系统平面稳态运动的稳定性

研究了中心力场中的一类刚-弹耦合系统的平面运动动力学，模型是带有一悬臂 梁的刚体. 综合考虑了系统轨道运动与姿态运动，在Lagrange力学体系下给出了系统的运 动方程，在保守系统和考虑梁的材料黏滞阻尼两种情况下，利用能量-动量方法给出了一类 相对平衡点稳定性的充分条件.     

基于集值决策的机载冗余惯导系统状态判决方法

针对多套惯导系统冗余配置中，余度管理策略的有效性和完备性难以分析和评估的问题，采用 集值信息系统构建机载冗余惯性参考系统状态集值决策系统，为余度管理策略的评估和分析提供理论 依据。分析传统机载惯性余度管理策略存在的决策风险，建立包含不确定项的冗余惯性参考系统状态 决策系统，并基于各状态隶属度函数评价各子系统状态变化特性，确保决策系统的完备性。开展仿真 试验，验证对比两种余度管理策略对三种典型的惯性传感器故障类型的故障识别率。试验结果表明： 改进的策略对于典型故障类型中的两种时变故障的识别率，相较于传统策略分别提高了 3.9%和 6.9%， 提高了判决指标接近判别门限时的状态判决准确性。     

二维联合概率分布函数构造方法对结构串联系统可靠度影响分析

简要介绍了两种构造联合分布函数近似方法：基于Pearson相关系数的近似方法P和基于Spearman相关系数的近似方法S。推导了基于直接积分方法的串联系统失效概率计算公式,提出了两构件功能函数间负相关时串联结构系统失效概率上限值的计算公式。以理论联合概率分布函数是二维极值分布为例研究了两种近似方法在串联系统可靠度计算中的精度。结果表明,两种近似方法能够有效地计算串联结构系统可靠度,且精度很高,为不完备概率信息条件下串联结构系统可靠度分析提供了一条有效的途径。当两构件的功能函数正相关时,两种近似方法误差随串联系统失效概率的减小而增加,但近似方法与精确方法系统失效概率的差别最大也不会超过2倍;当两构件的功能函数负相关时,两种近似方法误差随系统失效概率的减小而减小,但两种近似方法的失效概率几乎与精确解一样。此外,两种近似方法误差不是随构件间相关性的增加而单调增加,而是存在一极大值。     

范式理论与平均法的等价性分析

分析了范式理论与平均法的等价性。得到的结论是：对含有一对纯虚根的二维非线性系统，使用两种方法得到的结果是等价的，并提供了两个算例来证实其结论的正确性。虽然分析是针对一类二维非线性系统，但其结论同样适合于高维非线性系统。     

无陀螺捷联惯导系统中加速度计配置方式

对无陀螺捷联惯导系统中加速度计的几种配置方式及适用场合做了介绍，重点给出了适于近程战术导弹使用的两种六加速度计配置方式及相应的惯导计算公式，并对两种配置方式做了比较。     

Qualitative behaviors of the continuous-time chaotic dynamical systems describing the interaction of waves in plasma

In this paper, a new Lorenz-like chaotic system describing the interaction of three resonantly coupled waves in plasma is studied. Explicit ultimate boundedness and global attraction domain are derived according to stability theory of dynamical systems. The innovation of the paper is that this paper not only proves this chaotic system is globally bounded for the parameters of this system but also gives a family of mathematical expressions of global exponential attractive sets for this system with respect to the parameters of this system. Furthermore, the exponential rate of the trajectories is also obtained. Finally, numerical localization of attractor is presented.     

A Volterra Series Approach to the Approximation of Stochastic Nonlinear Dynamics

A response approximation method for stochastically excited, nonlinear, dynamic systems is presented. Herein, the output of the nonlinear system isapproximated by a finite-order Volterra series. The original nonlinear system is replaced by a bilinear system in order to determine the kernels of this series. The parameters of the bilinear system are determined by minimizing, in a statistical sense,the difference between the original system and the bilinear system. Application to a piecewise linear modelof a beam with a nonlinear one-sided supportillustrates the effectiveness of this approach in approximatingtruly nonlinear, stochastic response phenomena in both the statistical momentsand the power spectral density of the response of this system in case ofa white noise excitation.     

对一类强非线性系统的分析

本文研究了一类强非线性系统,首先对系统在相平面上的全局结构进行定性分析,得到了系统参数的分叉值,然后研究了摄动方法在定性分析中的应用。     

长输管道泄漏故障诊断方法的研究

将序贯概率比检测法（SPRT）应用到管道泄漏的在线故障诊断中，基于SPRT检测法提出了泄漏识别因子，该因子的提出大大提高了泄漏监测系统的识别精度。同时对于非稳定流体，引入了相对稳定过程的概念，通过对均衡流量的检验可以进行泄漏监测。最后，利用参数识别等方法对泄漏进行定位，实验结果证明了方法的有效性。     

Nonlinear response and nonsmooth bifurcations of an unbalanced machine-tool spindle-bearing system

In this effort, a six-degree-of-freedom (DOF) model is presented for the study of a machine-tool spindle-bearing system. The dynamics of machine-tool spindle system supported by ball bearings can be described by a set of second order nonlinear differential equations with piecewise stiffness and damping due to the bearing clearance. To investigate the effect of bearing clearance, bifurcations and routes to chaos of this nonsmooth system, numerical simulation is carried out. Numerical results show when the inner race touches the bearing ball with a low speed, grazing bifurcation occurs. The solutions of this system evolve from quasi-periodic to chaotic orbit, from period doubled orbit to periodic orbit, and from periodic orbit to quasi-periodic orbit through grazing bifurcations. In addition, the tori doubling process to chaos which usually occurs in the impact system is also observed in this spindle-bearing system.     

有限元—传递矩阵法求解链式结构非线性系统的动力响应

本文提出一分析多自由度非线性振动系统时域响应的数值计算法,并就一三自由度非线性系统,分别计算了此系统具有一个非线性弹簧、两个非线性弹簧和三个非线性弹簧三种情况下的动态响应;通过与对应的线性系统响应结果的比较,验证了此法的有效性、可靠性和多种优点.     

多体系统传递矩阵法研究进展

作为一种多体系统动力学新方法, 多体系统传递矩阵法由于其无需系统总体动力学方程和快速计算的特点, 已被广泛用于各种多管火箭、自行火炮、舰炮等复杂大型机械系统动力学分析与设计. 本文介绍了该方法的研究进展, 包括: 线性多体系统传递矩阵法、多体系统离散时间传递矩阵法、二维系统传递矩阵法、受控多体系统传递矩阵法、多体系统传递矩阵法和通常动力学方法的混合方法等, 给出了该方法解决自行火炮、多管火箭武器多体系统动力学的重大工程应用实例.      

A novel non-equilibrium fractional-order chaotic system and its complete synchronization by circuit implementation

In this paper, we construct a novel four dimensional fractional-order chaotic system. Compared with all the proposed chaotic systems until now, the biggest difference and most attractive place is that there exists no equilibrium point in this system. Those rigorous approaches, i.e., Melnikov??s and Shilnikov??s methods, fail to mathematically prove the existence of chaos in this kind of system under some parameters. To reconcile this awkward situation, we resort to circuit simulation experiment to accomplish this task. Before this, we use improved version of the Adams?CBashforth?CMoulton numerical algorithm to calculate this fractional-order chaotic system and show that the proposed fractional-order system with the order as low as 3.28 exhibits a chaotic attractor. Then an electronic circuit is designed for order q=0.9, from which we can observe that chaotic attractor does exist in this fractional-order system. Furthermore, based on the final value theorem of the Laplace transformation, synchronization of two novel fractional-order chaotic systems with the help of one-way coupling method is realized for order q=0.9. An electronic circuit is designed for hardware implementation to synchronize two novel fractional-order chaotic systems for the same order. The results for numerical simulations and circuit experiments are in very good agreement with each other, thus proving that chaos exists indeed in the proposed fractional-order system and the one-way coupling synchronization method is very effective to this system.     

Nonlinear dynamic singularity analysis of two interconnected synchronous generator system with 1:3 internal resonance and parametric principal resonance

The bifurcation analysis of a simple electric power system involving two synchronous generators connected by a transmission network to an infinite-bus is carried out in this paper. In this system, the infinite-bus voltage are considered to maintain two fluctuations in the amplitude and phase angle. The case of 1:3 internal resonance between the two modes in the presence of parametric principal resonance is considered and examined. The method of multiple scales is used to obtain the bifurcation equations of this system. Then, by employing the singularity method, the transition sets determining different bifurcation patterns of the system are obtained and analyzed, which reveal the effects of the infinite-bus voltage amplitude and phase fluctuations on bifurcation patterns of this system. Finally, the bifurcation patterns are all examined by bifurcation diagrams. The results obtained in this paper will contribute to a better understanding of the complex nonlinear dynamic behaviors in a two-machine infinite-bus (TMIB) power system.     

一种辩识多输入多输出振动系统参数的方法

本文讨论的是多输入、多输出串联振动系统传递函数的辩识问题.本文表明:从系统结构来看,多输入、多输出串联振动系统可以化成为多重交叉闭环系统.本文将这类振动系统的传递函数分解成多个二阶子系统.从系统辩识的角度出发,提出了一种通过辩识子系统传递函数,实现对整个系统传递函数辩识的新方法.仿真结果及模型实验结果表明:这种方法是可行的,且具有较高的精度.