航空测试用程控信号源设计

针对目前用于航空测试仪器校准的信号源现状,提出了一种基于PC104总线和直接数字频率合成技术的程控信号源设计方案。介绍了整个信号源系统的构成与工作原理,并详细叙述了其中DDS信号发生模块和功率放大模块的硬件设计。     

小型无人机实时仿真系统设计与实现

介绍了一种面向小型无人机实时仿真系统的设计与实现。系统的硬件平台采用PC/104总线的体系结构。利用RTKernel实时核开发基于DOS的实时多任务应用程序。文中就系统结构、飞机模型、传感器仿真、仿真算法、实时多任务应用程序编写进行了详细的论述。该系统已成功应用于某小型无人机仿真。     

基于PC/104总线的航姿系统智能检查仪的设计

针对PC/104总线测试系统具有体积小、功能强等特点,设计了基于PC/104总线的航姿系统智能检查仪。该检查仪具有智能化高,测试速度快、精度高,判读直观,操作简单等特点。     

基于ARINC429总线的 某型机载设备便携式检测设备

针对特定某种机载设备ARINC429总线通信状态的监测需求,设计了一种便携式检测设备。为了减小体积与重量,达到设计目标要求,该系统以PC/104嵌入式工业控制计算机结合ZHHK429-PC104-Plus429通信板卡为核心实现。文章描述了系统硬件的组成及原理,分析了软件结构及板卡的初始化、总线数据接收及发送的方法。经测试,该系统实时性好,可靠性高,可有效满足特定机载设备的状态监测及维护的需要。     

基于PC104总线的ARINC429航空接口卡设计

采用FPGA实现了基于PC104总线的ARINC429总线接口卡的设计,该接口卡可有效节约硬件资源,具有处理速度快、抗干扰能力强、成本低廉等特点,可广泛应用于以ARINC429总线作为通信方式的航空设备的通信测试维护中。     

基于PC／104总线的交流信号采集方法

介绍了一种用DIAMOND-MM-16-AT采集卡构建的基于PC 104总线的高速数据采集系统采集交流信号的方法,详细说明了采集卡的设置及初始化方法、变量定义及利用多线程、双缓冲区技术实现数据的高速采集和存储的方法,最后给出了滤波和计算交流有效值的算法。     

基于PC/104总线的飞机电源产品综合测试系统

详细介绍了一套基于PC／104总线和虚拟仪器技术的飞机电源产品综合测试系统的功能和软硬件实现原理。阐述了测试系统的设计原理，最后结合整个系统设计介绍了在LabVIEW环境下测试系统软件的设计和实现。     

激光推进中继折转系统的控制分系统性能仿真

为了在激光推进系统中实现对主激光的精确控制,设计了中继折转系统。中继折转系统以光学方法捕获信标光后实时解算出信标光和主激光方向并驱动中继折转镜调整姿态,实现自主闭环跟踪。控制分系统采用基于PC104总线架构方式,由电流环、速度环和位置环构成三环调节系统。对整个控制系统进行了计算机仿真,设计位置回路的跟踪带宽为2 Hz,速度回路的带宽为5 Hz,系统的跟踪精度小于0.4°。仿真结果表明,中继折转系统达到了设计要求的控制精度,能满足整个激光推进系统的使用要求。     

ARINC429总线信号测试平台的设计

本文基于对ARINC429总线信号的分析,提出了ARINC429总线信号测试平台的设计,该平台可以及时发现测模块的潜在故障,有利于提高ARINC429总线信号模块产品的质量水平。该测试平台可以实现对各类包含ARINC429总线功能的模块进行自动测试,减少了专用测试设备的研制,极大的缩减了测试设备的研制经费和维护成本。     

车载实时控制模块设计与实现

随着车载任务系统综合化的不断提高,对实时控制模块要求控制处理的内容也越来越多,不仅需要控制许多端口,还要进行算法的解算。介绍了一种高性能的实时控制模块的设计方案,方案包括了车载实时控制模块的系统结构、硬件设计及其软件配置。在硬件设计中详细描述了各个功能模块实现的方法。该系统基于美国模拟器件公司最先进的Tiger Shark 201 DSP处理器,该模块支持PCI、CPCI总线、A／D转换、数据存储等功能。     

基于飞机油箱模型形状特征油量测量切片步长选择方法研究

 在分析飞机数字式油量测量过程中目前广泛使用的切片法油量测量原理的基础上,针对现有的定步长切片法无法得到准确、可靠的燃油质量特性数据库的缺陷,结合对飞机油箱模型形状特征的分析,提出了基于飞机油箱模型形状特征的油量测量切片步长选择方法。此方法包括切片步长整体和局部选择两个过程,整体选择以实现相邻两切片平面所夹油箱模型体积近似相等为目的来确定切片步长,以体现油箱模型截面整体变化规律;局部选择以设计切片平面与截面突变平面重合或尽可能接近的方式,突出油箱截面的局部变化特征。实验结果表明：该切片步长选择方法较定步长方法能够建立更为合理、可靠的燃油质量特性数据库,从而提高了油量测量精度。     

The effect of inlet conditions on the flow and heat transfer in multiple rotating cavity with axial throughflow

This paper discusses experimental results from two different build configurations of a heated multiple rotating cavity test rig.Measurements of heat transfer from the discs and tangential velocities are presented.The test rig is a 70% full scale version of a high pressure compressor stack of an axial gas turbine engine.Of particular interest are the internal cylindrical cavities formed by adjacent discs and the interaction of these with a central axial throughflow of cooling air.Tests were carried out for a range of non-dimensional parameters representative of high pressure compressor internal air system flows(Re up to 5×106 and Rez up to 2×105).Two different builds have been tested.The most significant difference between these two build configurations is the size of the annular gap between the(non-rotating) drive shaft and the bores of the discs.The heat transfer data were obtained from thermocouple measurements of surface temperature and a conduction solution method.The velocity measurements were made using a two component,LDA system.The heat transfer results from the discs show differences between the two builds.This is attributed to the wider annular gap allowing more of the throughflow to penetrate into the cavity.There are also significant differences between the radial distributions of tangential velocity in the two builds of the test rig.For the narrow annular gap,there is an increase of non-dimensional tangential velocity V/Ωr with radial location to solid body rotation V/Ωr=1.For the wider annular gap,the non-dimensional velocities show a decrease with radial location to solid body rotation.      

二维翼段颤振的μ控制

 采用超声电机作为作动器来实现含控制面的翼段颤振鲁棒抑制。针对作者设计的二维翼段颤振主动抑制系统，通过理论与实验相结合的方法，建立了考虑沉浮方向阻尼和作动器模型参数不确定性的控制系统模型，设计了μ控制器，并对控制器做了降阶处理。数值仿真和风洞试验表明，μ控制器可有效地抑制颤振的发生，将颤振临界速度提高23.4%。相对于H_∞控制器，μ控制器的控制效果和鲁棒性更好。     

Abnormal Shape Mould Winding

为解决网格化芯模的缠绕问题,本文提出了复合材料面片缠绕机理;接着详细分析了面片缠绕过程中的芯模凹曲面上纤维滑线和架空现象,应用微分几何曲面理论和空间几何理论,提出判据及其解决方案;最后,针对飞机发动机进气道的缠绕成型,编制缠绕控制程序并进行相应的实验,验证了面片缠绕方法的可行性。     

基于H∞性能指标的质量矩拦截弹鲁棒控制

 以所建立的质量矩拦截弹数学模型为基础，利用微分几何的反馈线性化理论，得到一个解耦线性系统，考虑到拦截弹的鲁棒性要求和3个滑块的协调控制问题，提出采用双回路的设计方法，内回路采用线性二次调节器（LQR），外回路采用考虑混合灵敏度问题的H_∞控制设计。仿真结果证明了该方法动态性能满足设计要求，同时对系统参数的不确定性具有较强的鲁棒性。     

航天器返回地球的气动特性综述

航天器返回地球的飞行过程中,气动特性是实现将宇宙飞行速度减到落地前速度、保证再入飞行得到有效控制以及再入防热安全可靠的关键因素。针对简单旋成体气动外形、半弹道式再入控制、烧蚀防热类返回航天器,综述了返回地球过程中变化的空气流域特性、航天器周围的气体绕流环境、空气与航天器作用产生的动力学与热效应等。系统地给出了该类航天器的再入气动特性参数与飞行性能的共性规律,包括:气动阻力与再入减速、气动升力与再入轨迹控制、配平攻角与飞行稳定性、气动加热与防热,以及再入过程中不同气动特性航天器、气象条件变化等对再入飞行性能的影响规律。为航天器开展返回飞行过程的跨流域气动性能工程研制提供设计参考。     

Research on Auto-detection for Remainder Particles of Aerospace Relay Based on Wavelet Analysis

Aerospace relay is one kind of electronic components which is used widely in national defense system and aerospace system. The existence of remainder particles induces the reliability declining, which has become a severe problem in the development of aerospace relay. Traditional particle impact noise detection (PIND) method for remainder detection is ineffective for small particles, due to its low precision and involvement of subjective factors. An auto-detection method for PIND output signals is proposed in this paper, which is based on direct wavelet de-noising (DWD), cross-correlation analysis (CCA) and homo-filtering (HF), the method enhances the affectiv-ity of PIND test about the small particles. In the end, some practical PIND output signals are analysed, and the validity of this new method is proved.     

Effects of Mo on the Microstructure and Hydrogen Sorption Properties of Ti-Mo Getters

The effects of Mo on the microstructure evolution, porosity and hydrogen sorption properties of Ti-Mo getters are investigated in this work. The results show that the addition of Mo prolongs the densification process of Ti-Mo getters and results in a significant amount of sintered pores. With the Mo content increasing, the porosity of getters firstly increases reaching the maximum value as it at- tains about 7.5wt.%, and then drops. At the room temperature, the hydrogen sorption property of getters increases progressively with the Mo content increasing, but the tendency is not very clear before its content lies below 2.5wt.%. When the Mo content achieves about 7.5wt.%, the hydrogen sorption property proves to be the best. The discussion is made about the above mentioned phenomena inclusive of hydrogen sorption properties of getters under different activation conditions (from 500-750 ℃).     

Preparation of Highly Dispersed Antimony-doped Tin Oxide Nano-powder via Ion-exchange Hydrolysis of SnCl4 and SbCl3 and Azeotropic Drying

Antimony-doped tin hydroxide colloid precipitates have been synthesized by hydrolysis of SnCl4 and SbCl3 using: (1) an ion-exchange hydrolysis to remove chlorine ions, and (2) isoamyl acetate as an azeotropic solvent to obviate water. The obtained dried powder is of high dispersivity without any need for further grinding. The size and dispersivity of the final particles are investigated with the aid of TG-DTA, BET, XRD and TEM. After having calcined, the antimony-doped tin oxide nanopowder possesses a tetragonal rutile structure with high dispersivity, uniform particles and low hard agglomeration.