基于关键器件的光纤陀螺可靠性评估

以可靠性评估技术为基础,采用关键器件法对光纤陀螺工作状态下可靠性指标进行评估。通过对光纤陀螺实施故障模式、影响及危害性分析以及故障树分析,确定光纤陀螺的关键器件为超辐射发光二极管（SLD）光源,结合SLD光源性能退化数据对SLD光源进行可靠性评估,得到SLD光源的可靠度曲线。由关键器件转换法原理可知,曲线即为光纤陀螺工作状态下可靠度曲线。通过与整机法的评估结果进行对比,得出基于关键器件的光纤陀螺可靠性评估是可信的,为光纤陀螺可靠性评估提供了一种切实可行的方法。     

展望FOG在舰艇导航中的应用

在简述光纤陀螺（FOG）的发展与现状的基础上，对国外捷联式FOG航姿基准、FOG平台罗经和FOG在潜艇惯导系统中的应用进行了评述。最后，对我国发展基于FOG的舰载导航仪器提出几点建议。     

光纤陀螺在惯导系统中的建模及其应用

提出了一种适用于高精度光纤陀螺（FOG）的静态输出信号建模的改进型二阶自回归AR（2）模型，建立了FOG随机误差的实时卡尔曼滤波器，并在FOG捷联惯导系统（SINS）中进行了实际应用。Allan方差分析和实际应用表明，该建模和滤波方法有效减小了高精度FOG误差，在一定程度上提高了FOGSINS的静态初始对准精度，明显降低了导航漂移，提高了导航精度，具有较好的实际应用价值。     

光纤陀螺低温快速启动技术

光纤陀螺的启动时间与超辐射发光二极管(SLD)的输出性能密切相关。论文建立了SLD的ArcTan模型,并利用该模型分析光功率的温度敏感度和驱动电流敏感度。结果显示低温启动时,改变驱动电流可更快实现光功率稳定(与变温控制相比)。以此为指导设计了新型驱动电路,实现光功率自动控制,有效缩短光纤陀螺低温启动时间。论文描述了SLD的新型数学模型,设计出SLD的新型驱动电路。以低温(的40℃)启动时间较长(～8.5s)的陀螺仪表为应用对象,改进驱动电路后,该仪表可在2.5s内完成启动。     

基于SLD光源的谐振式光纤陀螺角度随机游走提升方法

针对基于超辐射发光二极管（SLD）光源的谐振式光纤陀螺角度随机游走提升需求,分析了移频复位特性非理想对陀螺输出的误差影响机理,建立了信号传输系统仿真模型,确定了移频锯齿波复位产生的尖峰脉冲噪声对陀螺输出的定量影响。在陀螺调制解调控制方案中,提出了一种部分采样结合均值滤波的技术方法,减小了锯齿波移频复位误差对解调系统的影响,提高了陀螺角度随机游走性能。经实验证明,使用部分采样结合均值滤波的方法测试光纤环直径50?mm、光纤长度30?m的基于SLD光源的谐振式光纤陀螺,陀螺角度随机游走提升了30%,达到0.045。     

基于粒子滤波的光纤陀螺寻北方案

为了降低噪声对光纤陀螺（FOG）寻北的影响,提高寻北速度和精度,提出了一种基于粒子滤波（PF）的光纤陀螺寻北方案。首先基于单轴光纤陀螺能够敏感地球自转角速率水平分量的输出特性,建立非线性光纤陀螺寻北系统的状态空间模型和观测模型。根据粒子滤波的基本原理,以及在解决非线性系统估计问题上的优势,利用粒子滤波来解算出光纤陀螺敏感轴与真北方向的夹角。仿真实验结果表明,该方案不仅可以在20至30倍采样时间间隔内快速获得寻北结果,而且可以有效解决光纤陀螺常值漂移和随机噪声的影响,其精度优于基于扩展卡尔曼滤波（EKF）的寻北结果。     

陀螺寻北仪中测量信号的在线建模与滤波

针对光纤陀螺寻北仪中光纤陀螺(FOG)和加速度计的随机误差,采用改进型二阶自回归AR(2)模型,在线建立了光纤陀螺和加速度计随机误差模型。根据该模型,建立了FOG陀螺寻北仪的12阶Kalman滤波器,实现了两个FOG和两个加速度计测量信号在寻北过程中的实时滤波。仿真、Allan方差分析与寻北试验结果表明:FOG信号中随机游走、零偏不稳定性、变化率随机游走、变化率斜坡和量化噪声五项噪声源误差系数都小于滤波前的二分之一;在减小光纤陀螺和加速度计测量信号中的随机误差,提高其精度的同时,FOG寻北仪的寻北误差减小了0.3 mil。     

光纤陀螺捷联式惯导系统初始对准方法研究

对光纤陀螺（FOG）的零偏重复性、零偏随时间变化规律的重复性进行了实骀研究。根据FOG零偏重复性好和零偏随时间变化规律的重复性好等特点，采用最小二乘估计和Kaiman滤波估计方法，提出、设计实现了一个有效实用的FOG捷联式惯导系统（SINS）初始对准方法，并与转位式初始对准方法的对准结果进行了比较，得到了精度相当的结果。     

数字闭环光纤陀螺复位电压控制技术研究

在数字闭环光纤陀螺(FOG)中，2π复位电压的准确度直接影响到陀螺的标度因数精度，对提高陀螺性能起着重要的作用。中对2π复位电压对标度因数的影响进行了理论分析，并在此基础上提出了建立第二反馈回路以稳定2π复位电压的控制方法。     

基于双模型的光纤陀螺温度补偿方法（英文）

基于Sagnac效应的光纤陀螺(FOG),因其自身的优点广泛地应用在捷联惯性导航系统中(SINS)。然而,温度对FOG的影响包括常值影响和随机影响,仍是制约光纤陀螺性能的关键因素之一。针对不同性质的漂移,首先建立基于相关性分析的多项式模型补偿常值漂移;然后结合时间序列分析的方法,利用Kalman滤波抑制经多项式模型补偿后残差信号中的随机成分,进一步提高FOG的精度。单轴光纤陀螺试验结果表明,传统的单多项式补偿模型,FOG的零偏稳定性能由0.05(°)/h仅提高到0.04(°)/h;采用常值和随机的双补偿模型,FOG的零偏稳定性能由0.05(°)/h提高到了0.01(°)/h。证明了双温度建模与补偿方法的有效性,在工程上有一定的参考价值。     

Some aspects of control systems as dynamical systems

Linear control semigroupsL=Gl(d,R) are associated with semilinear control systems of the form whereA:R ^m gl(d,R) is continuous in some open set containingU. The semigroupL then corresponds to the solutions with piecewise constant controls, i.e., L acts in a natural way onR ^d {0}, on the sphereS ^d–1, and on the projective spaceP ^d–1. Under the assumption that the group generated byL in Gl(d,R) acts transitively onP ^d–1, we analyze the control structure of the action ofL onP ^d–1: We characterize the sets inP ^d–1, where the system is controllable (the control sets) using perturbation theory of eigenvalues and (generalized) eigenspaces of the matrices g L For nonlinear control systems on finitedimensional manifoldsM, we study the linearization on the tangent bundleTM and the projective bundleP M via the theory of Morse decompositions, to obtain a characterization of the chain-recurrent components of the control flow onU×PM. These components correspond uniquely to the chain control sets onP M, and they induce a subbundle decomposition ofU×TM. These results are used to characterize the chain control sets ofL acting onP ^d–1 and to compare the control sets and chain control sets.Research supported in part by NSF Grant DMS 8813976 and DFG Grant Co 124/6-1.     

结构振动的非线性控制及其试验研究

本文分析了结构振动控制系统的特点，提出了一种结构振动的非线性离散控制方案，该方案仅利用受控结构的输出信号，实现容易，对结构参数变化具有一定的鲁棒性，本文还建立了一套具有浮点运算功能的结构振动计算机控制装置，并就某受控结进行了试验，试验表明，该非线性控制方案是可行的，理论结果与试验结果具有良好的一致性。     

Model-Based Feedback Control of Acoustic Radiation from Vibrating Structures by Means of Structural Control

In this work, it is investigated how classical techniques of linear feedback control design can be applied to the problem of the reduction of acoustic radiation from vibrating structures for cases where the disturbance is broadband and where no reference is available. Much of the work carried out to date in the field of active noise and vibration control has concentrated on applications where either the disturbance to be cancelled is periodic (propeller noise in aircraft,...) or a reference signal, highly correlated with the disturbance, is available (air conditioning duct noise,...) such that a feedforward control approach can be used. When the disturbance is broadband and where no reference is available, feedforward control cannot be used and feedback control must instead be used. Feedback control theory is well established and a vast amount of analytical tools are available to the feedback control designer. However, due to the inherent delays associated with the propagation of sound waves, feedback control of acoustic fields is prone to being unstable. In this paper, a controller is presented which feeds back a measure of the structural response (vibration) of the system in order to determine the control force that needs to be applied to the vibrating structure in order to reduce the total acoustic energy radiated by the vibrating structure. This revised version was published online in July 2006 with corrections to the Cover Date.     

石英挠性加速度计二元调宽数字脉冲控制系统的研制

本文介绍了石英挠性加速度计二元调宽数字脉冲控制系统的研制及其应用。提出了通过提高系统采样频率来抑制石英挠性加速度计摆片摆幅，从而最大限度地减小其疲劳强度的方法。并基于这一思想设计了石英挠性加速度计二元调宽数字脉冲控制模型，对模型进行了模拟仿真，证明该方案是合理可行的。其已成功地应用于各新型导航产品中     

Control of chaotic oscillations of a satellite

Analytical conditions and practical methods of their realization are proposed to solve a problem of a command signal tracking for a nonlinear disturbed system.Non- linear disturbed plants consisting of linear dynamic block and nonlinear block in feedback are considered.Nonlinear part of the plant and disturbance are unknown and bounded. The paper illustrates a possibility of applications of proposed algorithms to control libra- tion angle of satellite.     

复杂动态网络控制研究进展

研究复杂网络结构性质与模型的主要目的之一就是为了了解网络结构与网络功能之间的关系,并在此基础上考虑改善网络性能的有效途径.综述了近年关于利用分布式控制的方法使得一个动态网络具有期望行为的一些研究进展.对于具有固定和连通的拓扑结构的复杂动态网络,牵制控制策略的有效性与网络拓扑密切相关.综述了牵制控制的可行性、稳定性分析以及控制策略比较研究. 另一方面,对于具有时变拓扑结构的动态网络的控制,着重综述了移动多自主体网络系统的蜂拥控制,并特别阐述了如何把牵制控制的思想用于蜂拥控制.      

压电智能结构模糊自学习控制(FSLC)

将模糊逻辑与学习控制的基本思想相结合,根据控制系统的动态输出特性,采用模糊控制对学习控制律中的参数进行实时校正,实现系统的动态学习过程,提出了一种适用于压电智能结构振动控制的模糊自学控制方法FSLC（FuzzySelf-LearningContr01）。分别采用三维8节点实体单元（Solid45）和耦合单元模拟主结构和压电致动器／传感器,基于ANSYS参数化语言编写了压电智能结构振动控制分析的有限元程序。通过数值仿真证明了模糊自学习控制方法能有效控制压电结构的振动,并提高了自学习控制的收敛速度和获得了很好的控制效果。     

Numerical study comparing RANS and LES approaches on a circulation control airfoil

A numerical study over a nominally two-dimensional circulation control airfoil is performed using a large-eddy simulation code and two Reynolds-averaged Navier–Stokes codes. Different Coanda jet blowing conditions are investigated. In addition to investigating the influence of grid density, a comparison is made between incompressible and compressible flow solvers. The incompressible equations are found to yield negligible differences from the compressible equations up to at least a jet exit Mach number of 0.64. The effects of different turbulence models are also studied. Models that do not account for streamline curvature effects tend to predict jet separation from the Coanda surface too late, and can produce non-physical solutions at high blowing rates. Three different turbulence models that account for streamline curvature are compared with each other and with large eddy simulation solutions. All three models are found to predict the Coanda jet separation location reasonably well, but one of the models predicts specific flow field details near the Coanda surface prior to separation much better than the other two. All Reynolds-averaged Navier–Stokes computations produce higher circulation than large eddy simulation computations, with different stagnation point location and greater flow acceleration around the nose onto the upper surface. The precise reasons for the higher circulation are not clear, although it is not solely a function of predicting the jet separation location correctly.     

Adaptive robust fuzzy control for a class of uncertain chaotic systems

In this paper, the output feedback control of uncertain chaotic systems is addressed via an adaptive robust fuzzy approach. Fuzzy logic systems are employed to approximate uncertain nonlinear functions in the chaotic systems. Because only partial information of the system’s states is needed to be known, an observer is given to estimate the unmeasured states. Compared with the existing results in the observer design, the prior knowledge on dynamic uncertainties is relaxed and a class of more general chaotic systems is considered as well as robustness to the approximation error is improved. It can be proven that the closed-loop system is stable in the sense that all the variables are bounded. Simulation example for the unified chaotic systems is given to verify the effectiveness of the proposed method. This work was supported in part by the National Natural Science Foundation of China (60874056) and the Foundation of Educational Department of Liaoning Province (2008312).     

Design of bounded feedback controls for linear dynamical systems by using common Lyapunov functions

For a linear dynamical system, we address the problem of devising a bounded feedback control, which brings the system to the origin in finite time. The construction is based on the notion of a common Lyapunov function. It is shown that the constructed control remains effective in the presence of small perturbations.