LRE试验台加注系统故障建模与仿真分析

在对液体火箭发动机试验台推进剂加注系统进行结构分析的基础上,对加注系统进行模块化分解,建立其工作过程模型,分析了动态系统中故障注入的方式,对加注系统的两种典型故障进行了故障建模与仿真分析,仿真结果很好地描述了故障状态下加注系统的工作性能,通过分析仿真结果能进一步丰富和完善试验台故障知识库。

Abstract：

Based on the structural analysis for LRE test-bed propellant filling system. The filling system was modularized and its working model was built. The method of injecting fault was analyzed. Two typical fault modes were injected into model and the simulation results were analyzed. The results described preferably filling system＇s working capability in fault condition. The simulation results and analysis can also be used to enrich and perfect the fault knowledge base of test-bed.     

Hybrid chaotic sequence for QS-CDMA system with RAKE receiver

A class of the hybrid chaotic sequences is presented. The generator of the sequences is given and realized by the digital method. The hybrid chaotic sequences exhibit good random properties that are very important for the performance of QS-CDMA system with RAKE receiver. The performance of the system is analyzed when the hybrid chaotic sequences are used as spreading codes in a QS-CDMA system with RAKE receiver and compared with those obtained for m-se-quences and logistic sequences. The results show that the hybrid chaotic sequences are a class of very promising spreading codes for QS-CDMA system.     

STRONG CONVERGENCE OF MONOTONE HYBRID METHOD FOR FIXED POINT ITERATION PROCESSES*

K. Nakajo and W. Takahashi in 2003 proved the strong convergence theorems for nonex-pansive mappings, nonexpansive semigroups, and proximal point algorithm for zero point of monotone operators in Hilbert spaces by using the hybrid method in mathematical programming. The purpose of this paper is to modify the hybrid iteration method of K. Nakajo and W. Takahashi through the monotone hybrid method, and to prove strong convergence theorems. The convergence rate of iteration process of the monotone hybrid method is faster than that of the iteration process of the hybrid method of K. Nakajo and W. Takahashi. In the proofs in this article, Cauchy sequence method is used to avoid the use of the demiclosedness principle and Opial＇s condition.     

一种机械臂协调操作柔性负载的振动控制研究

基于柔性负载有限元模型,推导了负载振动的数学模型,分析了振动产生的原因。通过偏值点的引入设计任意阶数的EI成型器和多个波峰形式的Multi-EI成型器。利用成型器具有周期延伸特性抑制多模态柔性物体的振动,并把这一方法应用到机械臂协调操作柔性负载的振动控制中。对两个机械臂协调操作柔性负载进行了仿真,仿真结果证明了振动模型与成型器的有效性。

Abstract：

The vibration model was derived based on the finite element model.The causation for vibration was analyzed.The deviation value was introduced.Following this method,any order EI shapers could be designed by introducing the deviation value points.The Multi-EI shaper was designed.The method has these advantages that the design process is easier,the computational complexity is smaller and the robustness is better.The shaper is used to reduce the residual vibration of flexible object that has multiple mode,and then this method is used control the vibration of flexible object cooperated by robot manipulators.The simulation results prove the validity of vibration model and shaper.     

基于虚拟样机技术的航天器配重设计与实现

将航天器的质量、质心和转动惯量调配到一定目标范围内,可以降低航天器姿态控制的难度,提高航天器姿态控制的准确性,利用虚拟样机技术和数值优化技术的相关软件设计了航天器配重仿真优化方法,能够对航天器进行构件设计,仿真装配、动力学分析和可变装配参数优化,能够支持构件可变质量优化和装配位置优化,最后通过空间机器人地面气浮仿真平台的配重实例验证了配重方法的正确性,结果表明该方法可以有效地对航天器进行配重优化。

Abstract：

The mass, centroid and moment of inertia of spacecraft, regulated at a certain target range, can reduce the difficulty and improve accuracy in spacecraft stance control. The relative software of virtual prototyping and numerical optimization techniques were used for designing the methods of simulation and optimization in spacecraft balance. The methods could make spacecraft devised in components, simulation assembly, dynamic analysis and parameter optimization of variable assembly and support the components of variable quality optimization and assembly location optimization. The accuracy of balancing platform was validated by the balancing example of space robot ground floatation simulation platform. The result shows that spacecraft can be effectively balanced and optimized by this method.     

曲面薄壳有限元离散误差分析和修正方法研究

基于曲面薄壳几何/物理方程和有限元离散原理推导,揭示了壳单元离散方法特点、刚度矩阵误差产生机理和范数表示方法。以航空涡轮发动机测压探针为例,深入研究了利用协调平板壳单元、非协调平板壳单元、一次和二次实体退化壳单元等不同类型单元离散曲面薄壳时,应力计算误差影响因素及变化规律,综述了单元的适用条件。基于Boltzmann模型提出了应力计算结果修正通式,通过FORTRAN语言编程修正应力仿真结果和ANSYS二次开发语言APDL命令实现应力修正结果的读取和后处理,应力修正结果与理论解相对误差小于5%,满足曲面薄壳设计和稳定性分析应用要求。

Abstract：

Based on the geometric physical equations and deduction of discrete process of finite element for curved thin-walled structure,characteristics of shell elements for discretion and discrete error for element stiffness matrix were analyzed theoretically,and the norm expression of discrete error for element stiffness matrix was put forward.Then,as an illustration,a probe for detecting the pressure inside turboprops was meshed by curved thin-walled shell element,compatible flat shell element,incompatible flat shell element and 3D degenerated shell element,respectively,and the stress of the probe was numerically calculated by FEM.On the basis of solved results,the stress error was analyzed thoroughly,the influence factors on the error and the applying situations for different elements were determined.Finally,the general form of correctional function was put forward according to the Boltzmann model.The program developed with FORTRAN was used to correct the numerical results and the APDL commands inside ANSYS software were utilized to read and plot the correctional stress results.Through the correction,the discrete error can be reduced within 5% that satisfies the requirement of application for structural design and stability analysis.     

Researching and implementation of reconfigurable Hash chip based on FPGA

The reconfigurable cryptographic chip is an integrated circuit that is designed by means of the method of reconfigurable architecture, and is used for encryption and decryption. Many different cipher algorithms can be flexibly implemented with the aid of a reconfigurable cryptographic chip and can be used in many fields. This article takes an example for the SHA-1/224/256 algorithms, and then designs a reconfigurable cryptographic chip based on the thought and method of the reconfigurable architecture. Finally, this paper gives the implementation result based on the FPGA of the family of Stratix II of Altera Corporation, and presents a good research trend for resolving the storage in hardware implementation using FPGAs.     

用于装备体系分析的探索性分析及其工具研究

探索性分析是用于武器装备体系分析研究的一种有效分析方法,通过探索性分析,人们易于理解不确定性因素的影响,全面把握各种关键要素。分析研究了探索性分析基本方法和软件环境,并构建了相应的辅助工具,可有效解决分析过程中探索空间大、计算过程复杂等问题。

Abstract：

Exploratory analysis is an efficient analysis method for Study of Weapon Systems of Systems. The effect of uncertainties was understood easy by exploratory analysis, and many key elements are held. The actual computation method and software environment of exploratory analysis were studied, and the assistance tool was developed, which could resolve effectively problem of the too large space and complex computation procedure.     

Data-driven fault diagnosis method for analog circuits based on robust competitive agglomeration

The data-driven fault diagnosis methods can improve the reliability of analog circuits by using the data generated from it. The data have some characteristics, such as randomness and incompleteness, which lead to the diagnostic results being sensitive to the specific values and random noise. This paper presents a data-driven fault diagnosis method for analog circuits based on the robust competitive agglomeration (RCA), which can alleviate the incompleteness of the data by clustering with the competing process. And the robustness of the diagnostic results is enhanced by using the approach of robust statistics in RCA. A series of experiments are provided to demonstrate that RCA can classify the incomplete data with a high accuracy. The experimental results show that RCA is robust for the data needed to be classified as well as the parameters needed to be adjusted. The effectiveness of RCA in practical use is demonstrated by two analog circuits.     

Method of Chaotic Prediction Based on Wavelet BP Network and Its Application

The advantage of artificial neural network and wavelet analysis are integrated through replacing the traditional S-shaped activation function with the wavelet function. One method of chaotic prediction based on wavelet BP network was put forward based on the reconstruction of state space. Training data construction and networks structure are determined by chaotic phase space, and nonlinear relationship of phase points was established by BP neural networks. As an example, the new method was applied on short term forecasting of monthly precipitation time series of Sanjiang Plain with chaotic characteristics. The results showed so higher precision of the method had that the theoretical evidence would be provided for applying the chaos theory to study the variable law of monthly precipitation.     

COMBINING SINGULAR SPECTRUM ANALYSIS AND PAR（p） STRUCTURES TO MODEL WIND SPEED TIME SERIES

Singular spectrum analysis （SSA） is a technique that decomposes a time series into a set of components, such as, trend, harmonics, and residuals. Leaving out the residual components and adding up the others, the time series can be smoothed. This procedure has been used to model Brazilian electricity consumption and flow series. The PAR（p）, periodic autoregressive models, has been broadly used in modelling energy series in Brazil. This paper presents an approach of this decomposition method, by fitting the PAR（p）, considering its multivariate version known as multivariate SSA （MSSA）. The method was applied to a vector of two wind speed series recorded at two locations in the Brazilian Northeast region. The obtained results, when compared to the univariate decomposition of each series, were far superior, showing that the spatial correlation between the two series were considered by MSSA decomposition stage.     

Efficient analysis of dielectric radomes using multilevel fast multipole algorithm with CRWG basis

A full-wave analysis of the electromagnetic problem of a three-dimensional （3-D） antenna radiating through a 3-D dielectric radome is preserued. The problem is formulated using the Poggio-Miller-Chang-Harrington- Wu（PMCHW） approach for homogeneous dielectric objects and the electric field integral equation for conducting objects. The integral equations are discretized by the method of moment （MoM）, in which the conducting and dielectric surface/interfaces are represented by curvilinear triangular patches and the unknown equivalent electric and magnetic currents are expanded using curvilinear RWG basis functions. The resultant matrix equation is then solved by the multilevel fast multipole algorithm （MLFMA） and fast far-field approximation （FAFFA） is used to further accelerate the computation. The radiation patterns of dipole arrays in the presence of radomes are presented. The numerical results demonstrate the accuracy and versatility of this method.     

基于虚拟集成技术的ESP硬件在环仿真

针对汽车电子稳定性控制系统的开发,提出了集成ADAMS/Car的整车虚拟样机、MATLAB/Simulink的虚拟控制器和LabVIEW的测控平台的汽车电子稳定性控制的硬件在环仿真方法（VCHIL）,阐述了该方法的实现原理,讨论了基于虚拟集成技术的硬件在环仿真系统的组成及其相互关系,并以此为向导,研制了汽车电子稳定程序（ESP）的硬件在环仿真实验平台,并进行了实验验证。

Abstract：

Aiming at the development of ESP system,hardware-in-loop simulation method based on virtual cross technology （VCHIL）,which combined virtual modal by ADAMS/CAR,virtual controller by MATLAB/Simulink and LabVIEW platform,was addressed.The realization principle of the method was introduced.The structure and relation between parts of hardware-in-loop simulation system based on virtual cross technology were discussed,and according to these,the hardware-in-loop simulation testing platform was developed.Test on this platform was performed and the results were analyzed and compared.     

Information compression and speckle reduction for multifrequency polarimetric SAR images based on kernel PCA

Multifrequency polarimetric SAR imagery provides a very convenient approach for signal processing and acquisition of radar image. However, the amount of information is scattered in several images, and redundancies exist between different bands and polarizations. Similar to signal-polarimetric SAR image, multifrequency polarimetric SAR image is corrupted with speckle noise at the same time. A method of information compression and speckle reduction for multifrequency polarimetric SAR imagery is presented based on kernel principal component analysis （KPCA）. KPCA is a nonlinear generalization of the linear principal component analysis using the kernel trick. The NASA/JPL polarimetric SAR imagery of P, L, and C bands quadpolarizations is used for illustration. The experimental results show that KPCA has better capability in information compression and speckle reduction as compared with linear PCA.     

基于PDES的最小时间桶算法研究

混合策略在一定程度上避免了过分保守或极端乐观的缺点。首先分析了现有同步机制存在的不足,然后论述了视界概念及最小时间桶算法的设计与实现,接着对最小时间桶算法的性能进行了定性定量的深入探讨,最后采用PHOLD仿真应用模型在MTB算法、保守算法和TW乐观算法之间进行了性能对比实验,实验结果表明：MTB算法在某些条件下具有更小的回退开销和更快的事件处理效率。

Abstract：

Hybrid strategy to some certain extent avoids the shortcomings of the excessive conservation and extremely optimism. The shortcoming of the existing time synchronization algorithms was analyzed; then the very important conception of the event horizon,furthermore was proposed,and the design and the realization of the Minimum Time Buckets Algorithm were put forward. The remainder provided the farther research for the performance of this algorithm by qualitative analysis and quantitative analysis. Finally,the PHOLD simulation model was used to compare the performance of conservative algorithm,TW algorithm and MTB algorithm. The experiment results indicate that under some conditions MTB algorithm has lower rollback costs and faster event process speed,which lead to better performance than TW and conservative algorithms.     

Multi-parameters uncertainty analysis of logistic support process based on GERT

The uncertainty analysis is an effective sensitivity analysis method for system model analysis and optimization. However,the existing single-factor uncertainty analysis methods are not well used in the logistic support systems with multiple decision-making factors. The multiple transfer parameters graphical evaluation and review technique（MTP-GERT） is used to model the logistic support process in consideration of two important factors, support activity time and support activity resources, which are two primary causes for the logistic support process uncertainty. On this basis,a global sensitivity analysis（GSA） method based on covariance is designed to analyze the logistic support process uncertainty. The aircraft support process is selected as a case application which illustrates the validity of the proposed method to analyze the support process uncertainty, and some feasible recommendations are proposed for aircraft support decision making on carrier.     

一种新型UUV半实物仿真系统设计与实现

针对UUV导航与控制系统高精度仿真的需要,设计了一种支持捷联惯导、多普勒测速仪、深度传感器和GPS接收机接入的半实物仿真系统,解决了GPS卫星导航信号仿真、多普勒测速仪水声回波模拟和UUV深浅水航行深度模拟问题,进行了导航与控制系统的半实物仿真试验,分别测试了GPS导航仿真子系统、多普勒测速仿真子系统和深度模拟子系统。试验结果表明,该仿真系统满足了仿真实时性和计算精度的要求,对于UUV研制具有重要的应用价值。

Abstract：

To satisfy the requirement of high accuracy simulation of complicated navigation and control system of unmanned underwater vehicle, a new plan of simulation system was proposed, which afforded the interface environment for SINS, Doppler velocity instrument, depth sensor and GPS receiver. The GPS satellite navigation signal simulation, the acoustic echo of Doppler velocity instrument and the sailing depth simulation were solved. The simulation experimentation combining hardware was processed, and the GPS simulation subsystem, the Doppler velocity simulation subsystem and the sailing depth simulation subsystem were all tested. The results show that the simulation system meets the real-time and accuracy requirements, and the system has important application value for UUV development.     

Research on robust fault-tolerant control for networked control system with packet dropout

A kind of networked control system with network-induced delay and packet dropout, modeled on asynchronous dynamical systems was tested, and the integrity design of the networked control system with sensors failures and actuators failures was analyzed using hybrid systems technique based on the robust fault-tolerant control theory. The parametric expression of controller is given based on the feasible solution of linear matrix inequality. The simulation results are provided on the basis of detailed theoretical analysis, which further demonstrate the validity of the proposed schema.     

New Hybrid Genetic Algorithm for Vertex Cover Problems

This paper presents a new hybrid genetic algorithm for the vertex cover problems in which scan-repair and local improvement techniques are used for local optimization. With the hybrid approach, genetic algorithms are used to perform global exploration in a population, while neighborhood search methods are used to perform local exploitation around the chromosomes. The experimental results indicate that hybrid genetic algorithms can obtain solutions of excellent quality to the problem instances with different sizes. The pure genetic algorithms are outperformed by the neighborhood search heuristics procedures combined with genetic algorithms.