Pro/E工程图模块中专用符号自动标注的实现

通过应用实例，简要介绍了在Pro/Engineer工程图模块中，利用其符号和映射健自定义专用符号并实现自动标注的方法和技巧。     

基于稀疏符号时间序列分析的转子碰摩故障早期检测方法

引入稀疏混沌时间短序列概念,提出了稀疏符号时间序列分析方法与实现流程.利用映射空间关系对混沌振子的相变进行自治而快速辨识,以尽早而准确地捕捉表征转子碰摩早期的特征信号,进而实现对转子碰摩故障进行早期检测.仿真和数值实验均表明,基于稀疏符号时间序列分析方法可以对信噪比为-37.163 dB左右的微弱信号进行可靠检测,是一种具有实际应用价值的故障早期特征检测方法.     

基于混沌符号动力学的混沌运算电路

基于混沌符号动力学原理及单驱动恒流源混沌电路构造的1-D分段线性映射混沌系统,提出了一种能够实现混沌符号序列四则运算的混沌运算电路.用单驱动恒流源混沌电路所产生的12位长度混沌符号序列,并结合混沌符号运算的加法及减法原理对该运算电路进行了验证,结果表明在精度允许范围内,该电路的运算结果与传统的二进制编码算法完全等效.在验证过程中全部采用门电路,故结构简单、便于系统集成,此外该电路可应用于数字图像处理或数字加密等混沌信号处理系统中.     

结构模态多级分层并行计算方法EI北大核心CSCD

基于稀疏存储技术和传统并行模态综合法提出了一种有限元结构模态分析多级分层并行计算方法。该方法在两级分区4次变换策略的基础上不仅实现了大量数据的分布式稀疏存储,提高了数据的内存访问效率,而且实现了系统整体缩减后的广义特征方程规模的有效降低,大幅度减少了广义特征方程的求解时间。此外,它还利用计算任务和异构众核集群硬件体系结构映射实现了计算过程的多级并行,不仅有效改善了不同层级的负载均衡,而且通过通信分离有效提高了通信效率。因此,它能够充分利用异构众核分布式存储并行计算机的体系结构特点提升大规模有限元模态并行计算效率。数值算例表明,相比于传统的并行模态综合法,稀疏存储格式模态多级分层并行方法能够大幅度节省内存空间和提高计算效率。     

注水系统三级节流降噪设计及数值分析

大压差工况下,流量调节阀的节流作用导致自流注水系统振动噪声问题突出。为控制自流注水系统的噪声,从系统配置的角度进行系统降噪优化设计,提出了多级节流的降噪方案。采用流体动力学数值方法进行了多级节流低噪声设计原理分析,验证了多级节流降噪方案的有效性。基于低噪声设计原理,设计了三级流量调节阀串联的节流注水方案,并对三级节流系统进行了流场数值分析,数值分析结果表明:三级节流设计使各级阀后低压区减小,避免了阀后局部气蚀出现;一级阀门和二级阀门进口下缘及出口上缘均出现大尺度的漩涡结构,为主要噪声源区域。     

星载串联型柔性抓捕机构的多级阻尼镇定控制

利用星载抓捕机构进行航天器对接是实现在轨操作的重要环节,对接引入的碰撞力易引起抓捕机构及漂浮基座的扰动失稳。针对捕获后不稳定系统的镇定控制问题,提出了一种具有多级可控阻尼的串联型柔性抓捕机构广义模型,并利用Kane方法建立了漂浮基座耦合柔性抓捕机构的一体化动力学方程。将全局分散的多级阻尼力模化为微粒群,构建了目标适应度函数,基于微粒群优化算法实现了不稳定系统的多级阻尼优化镇定控制。对某型星载12自由度柔性抓捕机构进行数值仿真,结果表明提出的控制方法能显著改善基座和柔性抓捕机构的动力学响应,保证系统渐近稳定。在研制的二关节四级阻尼柔性抓捕机构原理样机上开展捕获碰撞模拟实验,验证了多级阻尼镇定控制方法的有效性。     

金属多级雾化制粉及其单级过程原理综述

综合评述了金属多级雾化过程的原理，介绍了多级雾化的方法，成粉原理及其进一步研究的方向，概述了其单级过程即气体雾化和旋转盘离心 经过程的制粉机理、数学模型，传热研究，并且提出了存在的问题。     

基于神经网络的产品文化符号意象认知评价方法研究

目的 利用神经网络建立产品文化符号特征元素与意象认知的映射关系,将文化符号的特征元素与用户的感知意象相关联.方法 首先,收集意象认知词汇,通过焦点小组选择符合整体意象认知的词汇,根据词频统计提取核心语义词汇;然后,利用里克特量表法针对测试样本进行核心语义词汇符合程度评价,并对语义核心词汇进行主成分分析,提取主成分权重系数,得到测试样本的综合意象评价值;最后,运用神经网络工具箱将特征元素与综合意象评价值进行映射关系分析.结果 将抽样数据与神经网络得出的数据进行对比验证,数值基本接近,将全部随机变量输入神经网络得到综合意象评价值最高和最低的特征元素组合,剔除相关性弱的特征元素.结论 通过基于神经网络的产品文化符号意象认知的评价方法可以建立文化符号特征元素与综合意象评价认知的映射关系,得到相关性强的特征元素,为运用理性的思维设计出满足用户文化需求的产品提供了数据与图形结构参考.     

传统文化符号在产品隐喻设计中的应用

目的 探讨传统文化符号的隐喻特征及其在现代设计中的应用价值和意义,构建传统文化符号隐喻机制及隐喻设计方法。方法 从修辞学角度,研究传统文化符号的隐喻特征,探讨如何对传统文化符号特征进行抽象提炼。基于事物之间的相似性,实现从来源到目标的映射关系,实现对文化符号意义的传达。重点提出基于人类认知的隐喻设计方法理论框架,并运用案例分析法,进一步地论证应用方法的可行性。结论 传统文化符号具有深远的传承价值和意义。通过现代产品中的隐喻设计,不仅可以传达其自身隐含的价值和意义,为设计师提供创意源泉和设计思路,而且可以实现文化认同,丰富现代产品设计的语义。这为文化产品的构思与设计提供了系统清晰的研究思路,为现代产品设计提供新的设计思路和理论思考。     

电子全息高分辨率三维数值重现

对电子全息图进行计算机三维数值重现时，由于样品各层电子衍射的干扰，影响了纵向分辨率的提高。本提出一种基于多能量电子全息图数值重现像叠加原理的新方法，可以提高险息数值重现纵向分辨率，从而实现真正的三维数值重现的含义。还通过计算机模拟研究的手段对该原理和方法的有效性进行了验是出了有价值的结果。     

基于任务的神经网络多传感器数据融合新方法

面向遥操作机器人系统对传感和控制的具体要求及条件,提出一种基于任务的神经网络多传感器数据融合新方法。根据遥操作过程中的不同任务,利用优化的神经网络算法,对双视觉、六维力／力矩、接近觉（数字／模拟）、指端力、关节角度等多种传感器信息进行融合决策,并实时地将融合结果反馈回上层控制系统。     

Structure of synchronized chaos studied by symbolic analysis in velocity-curvature space

A new method of symbolic analysis based on finite discretization of velocity-curvature space is proposed. A minimum alphabet is introduced in a natural way, and a number of initial analytic measures are defined that make it possible to study the structure of discrete mapping dynamics. The proposed method is tested by application to a system of two unidirectionally coupled logistic maps. It is shown that this method can be used to reveal and study changes in the structure of attractors. In the given example, features in the attractor structure of the driven subsystem are studied upon its escape from the identical synchronization regime.     

Data acquisition, analysis and applications of multi-sensor integration

This paper presents some key techniques for multisensor integration system, which is applied to the intelligent transportation system industry and surveying and mapping industry, e.g. road surface condition detection, digital map making. The techniques are synchronization control of multisensor, spacetime benchmark for sensor data, and multisensor data fusion and mining. Firstly, synchronization control of multisensor is achieved through a synchronization control system which is composed of a time synchronization controller and some synchronization subcontrollers. The time synchronization controller can receive GPS time information from GPS satellites, relative distance information from distance measuring instrument and send spacetime information to the synchronization subcontroller. The latter can work at three types of synchronization mode, i.e. active synchronization, passive synchronization and time service synchronization. Secondly, spacetime benchmark can be established based on GPS time and global reference coordinate system, and can be obtained through position and azimuth determining system and synchronization control system. Thirdly, there are many types of data fusion and mining, e.g. GPS/Gyro/DMI data fusion, data fusion between stereophotogrammetry and PADS, data fusion between laser scanner and PADS, and data fusion between CCD camera and laser scanner. Finally, all these solutions presented in paper have been applied to two areas, i.e. landborne intelligent road detection and measurement system and 3D measurement system based on unmanned helicopter. The former has equipped some highway engineering Co., Ltd. and has been successfully put into use. The latter is an ongoing research.     

Model of retinal local adaptation for the tone mapping of color filter array images

We present a tone mapping algorithm that is derived from a model of retinal processing. Our approach has two major improvements over existing methods. First, tone mapping is applied directly on the mosaic image captured by the sensor, analogous to the human visual system that applies a nonlinearity to the chromatic responses captured by the cone mosaic. This reduces the number of necessary operations by a factor 3. Second, we introduce a variation of the center/surround class of local tone mapping algorithms, which are known to increase the local contrast of images but tend to create artifacts. Our method gives a good improvement in contrast while avoiding halos and maintaining good global appearance. Like traditional center/surround algorithms, our method uses a weighted average of surrounding pixel values. Instead of being used directly, the weighted average serves as a variable in the Naka-Rushton equation, which models the photoreceptors' nonlinearity. Our algorithm provides pleasing results on various images with different scene content and dynamic range.     

多视点距离图象集成的截平面法

利用截平面进行了多视点距离图象的集成。和基于三维空间上的几何特征或直接进行曲面匹配的集成方法相比，截平面法具有计算简单等优点。所得到的物体轮廓曲线表示也很容易转换为更高一级的表示。实验结果表明，截平面法在表示的精度和处理速度上都有很好的实用价值。     

Coupled multi‐scale cohesive modeling of failure in heterogeneous adhesives

A multi‐scale cohesive numerical framework is proposed to simulate the failure of heterogeneous adhesively bonded systems. This multi‐scale scheme is based on Hill's variational principle of energy equivalence between the higher and lower level scales. It provides an easy way to obtain accurate homogenized macroscopic properties while capturing the physics of failure processes at the micro‐scale in sufficient detail. We use an isotropic rate‐dependent damage model to mimic the failure response of the constituents of heterogeneous adhesives. The finite element method is used to solve the equilibrium equation at each scale. A nested iterative scheme inspired by the return mapping algorithm used in computational inelasticity is implemented. We propose a computationally attractive technique to couple the macro‐ and micro‐scales for rate‐dependent constitutive laws. We introduce an adhesive patch test to study the numerical performance, including spatial and temporal convergence of the multi‐scale scheme. We compare the solution of the multi‐scale cohesive scheme with a direct numerical simulation. Finally, we solve mode I and mode II fracture problems to demonstrate failure at the macro‐scale. Copyright © 2010 John Wiley & Sons, Ltd.     

多传感器信息融合在电机故障诊断中的应用

为了提高电机故障诊断的准确性,引入一种多传感器信息融合的诊断方法。将多个传感器所采集的转子振动频谱信号处理后,利用蚁群神经网络进行故障局部诊断,以获得彼此独立的证据,再由证据理论对各证据进行融合,最终实现对电机故障的准确诊断。实验结果表明,该方法有效提高诊断的可信度,减少电机故障分类识别的不确定性。     

Short communication optimal replacement scheduling in multi‐state series–parallel systems

The paper generalizes a replacement schedule optimization problem to multi‐state systems, where the system and its components have a range of performance levels—from perfect functioning to complete failure. The multi‐state system reliability is defined as the ability to satisfy a demand which is represented as a required system performance level. The reliability of system elements is characterized by their lifetime distributions with hazard rates increasing in time and is specified as expected number of failures during different time intervals. The optimal number of element replacements during the study period is defined as that which provides the desired level of the system reliability by minimum sum of maintenance cost and cost of unsupplied demand caused by failures. To evaluate multi‐state system reliability, a universal generating function technique is applied. A genetic algorithm (GA) is used as an optimization technique. Examples of the optimal replacement schedule determination are demonstrated. Copyright © 2000 John Wiley & Sons, Ltd.     

圆柱结构声辐射估计中的振动传感器数目要求

使用近似Kirchhoff积分法估计点力源激励下圆柱壳体的辐射声压和声功率,研究壳体表面速度传感器均匀布放时传感器数目对估计精度的影响。单个场点声压估计和声功率估计误差给定的情况下,随着频率的升高,所需的传感器越来越多,但在场点声压级曲线或辐射声功率级曲线的峰值频率附近,需要的传感器数目会出现谷值;且激励源位置对单个场点声压估计时的传感器数目要求影响不大。进一步研究了全空间声压估计时的传感器数目需求,发现此时传感器需求数目曲线比单个场点声压估计时的传感器数目需求曲线平滑,不会在曲线峰值频率附近出现谷值。     

基于TCS230的颜色检测装置及其在智能装配机器人避障中的应用

为使机器人躲避路障,开发了基于TCS230的颜色检测装置．红外传感器或色标传感器作为检测颜色的手段无法实现场景中多种颜色分辨,而颜色检测装置中的传感器TCS230能够将颜色信号转变成为相对应的频率信号并传递给单片机,单片机获取频率信号后,应用测频程序分辨物体颜色,适用于多颜色分辨场合．该颜色检测装置装配到智能装配机器人上进行动态避障应用时,受到临界位置和振动等多种因素的影响,检测准确率不高．采用并行双测法和延时检测法解决了临界位置影响产生的误判,研发出T型槽联结双传感器结构和软件均值滤波方法,减少了运动过程中振动引起的测量误差．该装置应用到智能装配机器人的避障策略中,取得了良好的效果．该颜色检测装置的开发应用可以推广到工业生产相关的颜色分辨场合．