高速数字图像数据传输的研究及实现

随着CCD相机几何分辨率和辐射分辨率的提高,其数据传输速率越来越高,传输通道也越来越多,因此对相机与采集卡之间（或者数传设备）的接口性能提出了更高的要求。文章基于并／串（串／并）转换功能的芯片．研究探讨了一种高速数字图像传输方法,可提高数据传输率,减少电缆数量,提高可靠性,为实现航天相机的轻型化、小型化作出一定的贡献。     

Sound insulation performance of plates with interconnected distributed piezoelectric patches

This paper deals with the sound insulation performance of a thin plate with intercon-nected distributed piezoelectric patches. Piezoelectric patches are periodically bonded on the sur-faces of the plate in a collocated fashion, and are interconnected via an inductive circuit network. This piezoelectric system is termed as piezo-electromechanical (PEM) plate in the paper. Homogenization methods are involved under a sub-wavelength assumption to analytically develop the dynamical equations for the PEM plate. The dispersion relationships and energy densities of the wave modes propagating in the PEM plate are studied;the sub-wavelength assumption is verified for the simulations in this paper. The coincidence frequency of the PEM plate is researched, and results show that the coincidence frequency of the PEM plate will disappear at certain circum-stances;mathematical and physical explanations are made for this phenomenon. The disappearance of the coincidence frequency is used to optimize the value of inductance, for the purpose of improv-ing the sound transmission loss of the PEM plate.     

无余量装配技术在复合材料机身结构部段上的应用

提出了在复合材料飞机部段装配过程中采用无余量装配的方法。在产品设计和制造过程中采用数字量传递的方式可减少误差积累,提高协调精度。关键零部件的装配、工装制造等采用激光跟踪仪等数字化测量设备可以确保精确性,并能在装配工艺设计阶段就考虑零部件间的协调安装精度及公差分配要求。通过分析复合材料部段装配特点,并以复合材料机身典型结构为例进行应用研究,阐述了在三维数字化装配过程中具有协调关系的关键零部件无余量装配的工艺流程、方法,从而可实现零部件一次装夹、加工及无反复装配,使装配质量具有良好的稳定性。     

基于线结构光的飞机蒙皮对缝阶差与间隙测量技术研究

针对飞机蒙皮对缝阶差与间隙的数字化检测问题,以线结构光视觉测量技术为基础,提出了阶差与间隙测量模型,从阶差与间隙的尺寸和位置两个方面设计测量方法。使用线结构光视觉传感器完成阶差与间隙的尺寸测量,同时利用iGPS测量系统对视觉传感器的位姿进行实时跟踪测量,从而确定阶差与间隙的测量位置。通过试验验证了算法的正确性和稳定性,能够实现非接触、高精度测量:试验结果表明:5mm内阶差的重复测量精度优于0.04mm,间隙的重复测量精度优于0.05mm。     

弧齿锥齿轮啮合迹方向角的主动设计方法

为了实现弧齿锥齿轮设计规定的啮合迹方向,以局部综合法为基础,结合轮齿接触分析技术和无约束优化方法,进行弧齿锥齿轮啮合迹方向角的主动设计,给出了1种实现齿面参考点处啮合迹目标方向角的设计方法。通过1对弧齿锥齿轮的实例演示,论证了该方法对弧齿锥齿轮啮合迹方向角进行主动设计的可行性。结果表明:局部综合法中的输入啮合迹方向角必须小于旋转轴平面中规定的角度;在调整啮合迹方向角的过程中,传动误差曲线没有发生畸变。     

数据格式转换技术在精密测量中的应用

叙述了为提高数据传输可靠性,在接收精密仪器所采集的数据过程中考虑将原有RS232串口通信,改进为USB接口通讯。但是接收到的信号出现了不明原因的周期性强干扰。为此,通过分析USB/RS232转换原理及A/D采集输出数据特点,对原软件的数据采集部分增补了具有特殊功能的子程序,使得应用程序可以自行恢复数据的完整性。此方法具有通用性,可在不同软件编辑环境中实现,且不影响硬件组成。文中又详细介绍了在薄膜厚度在线测量中应用上述USB接口通信的情况,实测结果表明试验取得了预想的效果。改进后的电容测量系统具有更为广泛的应用前景。     

最佳传力特性的偏置曲柄滑块机构解析法设计

本文根据偏置曲柄滑块机构的运动特性和传力特性所建立的函数关系，运用极值理论推导出给定条件下传力特性最佳的计算公式，大大方便了设计应用，值得推广。     

软件无线电概念及直接中频采样软件接收机方案

软件无线电是最近几年提出的一种实现无线电通信的新的体系结构，文章介绍了软件无线电的概念、特点、历史和现状，并且提出和分析了直接中频采样软件接收机实现方案。     

Multiple-site investigation of the properties of an HF radio channel and the ionosphere using Digital Radio Mondiale broadcasting

The Digital Radio Mondiale (DRM), one of the new digital radio broadcasting standards, has been designed to overcome typical short wave radio channel difficulties, such as the multipath propagation and fast temporal changes of the received signal level, both related to the properties of the ionosphere along the path of propagation. In particular, some of the RF carriers used in the applied COFDM transmission technique serve to estimate the current state of the radio channel to enable the proper demodulation of the received signal.We have been detecting such RF carriers on select frequency channels (standard DRM broadcast) using a network of recording stations located in different parts of Poland in order to collect data on the HF radio channel. We have been also evaluating the usefulness of this procedure in providing information on the current state of the ionosphere in the refraction region between the transmitter and receivers. When the DRM system becomes more widespread, this method can supplement data that comes from the ionosondes, since it does not require much financial resources and the receivers can be easily scattered over a large area. This paper presents a set of experimental data and its analysis.     

ATM局域网仿真技术

简要介绍了 Ａ Ｔ Ｍ 局域网仿真的主要原理，以 Ｉ Ｂ Ｍ ８２６０ Ａ Ｔ Ｍ 交换机为例，具体分析了 Ａ Ｔ Ｍ 局域网仿真的实现细节。