基于MEMS传感器的姿态检测系统

基于MEMS传感器设计了一种姿态检测系统,通过MEMS传感器获取角速度、加速度等信息,利用硬件对采集的数据进行滤波处理,实现目标物体运动过程中姿态角的测量。采用互补滤波对数据进行融合,有效消除了噪声干扰,提高了系统的检测精度。无线模块的应用实现了下位机与上位机的同步,实时显示目标物体的运动姿态。实验表明,该系统具有较高的测量精度及良好的实时显示效果。     

基于太阳矢量和MEMS的自旋弹姿态估计系统研究

针对自旋弹提出了一种新的姿态估计方法。首先,根据自旋弹的性质设计了一种特殊的太阳矢量测量装置,用来测量太阳矢量并替代常用的MEMS中的加速度计和地磁计来修正陀螺仪偏差。该太阳矢量测量装置包括透明外壳、光电池阵列、实时时钟和处理器,太阳透过透明外壳照射光电池阵列,该阵列将太阳能转换成电动势信号,并结合实时时钟、通过处理器处理得到该时刻的太阳矢量。然后,通过四元数微分方程建立卡尔曼滤波状态方程和观测方程对自旋弹进行姿态估计。最后,仿真结果表明该方法能够得到较高精度的自旋弹姿态角。     

基于MEKF的捷联惯导初始对准算法研究

在某些对精度要求不是很高的领域微机电系统(MEMS)等低精度捷联惯导系统因其造价低等特点而得到广泛应用。由于传统的初始对准方法不能估计除姿态以外的任何量,故不适用于MEMS等低精度捷联惯导系统。该文研究了一种基于姿态估计的初始对准方法,并使用乘性扩展卡尔曼滤波进行对准,在姿态对准的同时实现对惯性器件误差的建模估计。在实现初始对准的基础上显著降低了计算量。     

融合多传感信息的仿人机器人姿态解算

在RoboCup Soccer仿人机器人比赛中,机体姿态实时解算是仿人机器人运动控制系统的核心技术之一。文中分析了MEMS加速度计、磁强计和陀螺仪性能,以自主姿态测量为前提,融合惯性测量单元中多传感信息,提出了一种基于四元数的姿态解算算法。针对仿人机器人步行姿态控制中传感器数据存在的噪声干扰和测量误差,设计卡尔曼滤波器实现了对数据漂移的有效补偿,从而提高了全姿态检测的测量精度。试验结果验证了该算法对仿人机器人运动控制系统机体姿态实时解算的有效性。     

基于MEMS的测姿定向方法研究

针对 MEMS 惯性器件精度较低,MEMS 惯导系统无法满足平台姿态精度要求的问题,本文提出了一种基于 MEMS 器件的测姿、定向方法。当载体近匀速运动时,利用加速度计和磁力计信息,采用垂直陀螺原理得到高精度的姿态信息,通过卡尔曼滤波估计出陀螺漂移,载体非近匀速运动时采用惯性姿态递推更新算法,补偿修正力矩和陀螺漂移误差,提高了载体的测姿定向精度。实验测试结果表明,采用本文的测姿定向方法后 MEMS 系统的姿态精度达到了 0.6°, 精度明显高于传统方法的精度,能够满足大多数中高精度平台的要求。     

CCD成像单元仿真系统的实时显示方法研究

依据某型号航天光学遥感器内部系统通信协议,对CCD成像单元仿真系统在通信过程中的实时显示方法进行了研究.提出了一种利用计算机仿真技术,以计算机算法控制为核心,以通信控制电路为基础的实时显示实现的方法.阐述了航天光学遥感器CCD成像单元仿真系统的工作原理;分析了CCD成像单元仿真系统实时性需求,并应用微秒级精度的定时器对实时显示时间进行定时测试.经过实验证明,该方法满足预定要求,实现了仿真环境下的实时显示,完成了对航天光学遥感器内部遥感器控制单元的检测.     

基于数字图像处理的星体检测技术研究

简述了基于CCD器件昼夜星体检测系统的组成和原理,针对影响星体检测精度的关键因素,采用质心法确定恒星位置,较详细分析了提高信噪比的图像处理算法和亚像元定位算法,对以恒星为基准的实时、多参数校正设备实现高精度的测量。     

基于CCD成像单元仿真测试系统的实时性实现

依据某型号航天光学遥感器内部系统通信协议,在CCD成像单元仿真测试系统的基础上,提出了一种利用计算机检测与仿真技术结合,以计算机算法控制为核心,以通信控制电路为基础的实时性实现的新方法.阐述了航天光学遥感器CCD成像单元仿真测试系统的工作原理及功能;分析了CCD成像单元仿真测试系统实时性需求,并应用微秒级精度的定时器对实时显示时间和实时存储时间进行定时测试,经过实验证明,该方法满足预定的实时通信要求,实现了仿真测试环境下的实时性显示与存储,完成了对航天光学遥感器内部遥感器控制单元的检测.     

一种基于高精度CCD的星敏感器系统设计

CCD作为实时、高精度姿态测量部件,对空间飞行器的姿控、导航、定位具有重要意义。本文对CCD星敏感器遮光罩、光学系统、电路系统硬件及导航星库制定、星图识别、姿态计算软件算法等星敏感器技术实现进行了系统阐述,并提出星敏感器系统设计方案。经实验室静、动态检验和观星检验,该系统可以满足卫星姿轨控系统提出的精度要求。     

基于递推最小二乘算法的惯导姿态误差动态标定方法

在分析最小二乘算法原理的基础上,提出了一种基于递推最小二乘算法的惯导姿态误差动态标定方法,建立了计算模型,进行了仿真分析.仿真结果表明,该方法具有较高的解算精度和计算效率,航向误差解算精度优于3.5”,水平误差解算精度优于0.15".该方法解决了动态条件下惯导姿态误差实时标定的技术难题,对提高惯导姿态测量精度和测量船外...     

聚对苯撑苯并双(口恶)唑发光及其器件制备

采用光谱技术,研究了聚对苯撑苯并双(口恶)唑(PBO)溶液的光敏发光特性,并用相对法估算出溶液发光效率在50%范围.结合光谱技术、半导体电学和电化学等研究手段,具体研究了以PBO为发光层的单层电致发光器件,研究结果显示,电致发光与薄膜的光致发光有具有相同的发光中心,峰值位于510 nm左右.同时发现,由于存制备过程中不同处理条件使得不同厚度薄膜残留的掺杂物质浓度不同,从而引起薄膜的导电性的不同.使得器件的阈值场强随PBO厚度的减小而逐渐增加.     

系统级封装新型埋入式电源滤波结构的研究

在高密度小尺寸的系统级封装(SiP)中,对供电系统的完整性要求越来越高,多芯片共用一个电源网路所产生的电压抖动除了会影响到芯片的正常工作,还会通过供电网路干扰到临近电路和其他敏感电路,导致芯片误动作,以及信号完整性和其他电磁干扰问题.这种电压抖动所占频带相当宽,几百MHz到几个GHz的中频电源噪声普通方法很难去除.结合埋入式电容和电源分割方法的特点,提出一种新型高性能埋入式电源低通滤波结构直接替代电源/地平面.研究表明,在0.65～4GHz的频带内隔离深度可达-40～75 dB,电源阻抗均在0.25ohm以下,实现了宽频高隔离度的高性能滤波作用.分别用电磁场和广义传输线两种仿真器模拟,高频等效电路模型分析这种低通滤波器的工作原理以及结构对隔离性能的影响,并进行了实验验证.     

Emerging interconnects: a state-of-the-art review and emerging solutions

Aluminium was a primary material for interconnection in integrated circuits (ICs) since their inception. Later, copper was introduced as interconnect material which has better metallic conductivity and resistance to electromigration. As the aggressive technology scaling continues, the copper resistivity increased because of size effects, which causes increase in delay, power dissipation and electromigration. The need to reduce the resistor-capacitor??????? delay, dynamic power utilisation and the crosstalk commotion is as of now the fundamental main impetus behind the presentation of new materials. The purpose of this paper is to do a survey of interconnect material used in IC from introduction of ICs to till date. This paper studies and reviews new materials available for interconnect application which are optical interconnects, carbon nanotube (CNT), graphene nanoribbons (GNRs) and silicon nanowires which are alternatives to copper. While doing a survey of interconnect material, it is found that multiwalled CNTs, multilayer GNR and mixed CNT bundles are promising candidates and are ultimate choice that can strongly address the problems faced by copper but on integration basis copper would last for coming years.     

Arsenic deposition as a precursor layer on silicon (211) and (311) surfaces

We investigate the properties of arsenic (As) covered Si(211) and Si(311) surfaces by analyzing data from x-ray photoelectron spectroscopy (XPS) and low-energy electron diffraction (LEED) images. We then create a model using total surface energy calculations. It was found that both Si(211) and Si(311) had 0.68±0.08 surface As coverage. Si(211) had 0.28±0.04 Te coverage and Si(311) had 0.24±0.04 Te coverage. The Si(211) surface replaces the terrace and trench Si atoms with As for a lower surface energy, while the Si edge atoms form dimers. The Si(311) surface replaces all terrace atoms and adsorbs an As dimer every other edge site. These configurations imply an improvement in the mean migration path from the bare silicon surface by allowing the impinging atoms for the next epitaxial layer, tellurium (Te), to bind at every other pair of edge atoms, and not the step terrace sites. This would ensure a nonpolar, B-face growth.     

光子晶体微腔发光二极管

光子晶体微腔因其具有增强自发辐射、定向输出和单模工作的能力而受到广泛关注。介绍了光子晶体微腔发光二极管的基本原理、设计、特性、制作及其典型器件。     

Comparative study of maximum power point tracking techniques for hybrid renewable energy system

The power generation demand is increasing day-by-day throughout the world, therefore, the use of hybrid systems becomes a significant solution. The hybrid renewable energy system (HRES) is used for delivering power in various regions in order to overcome intermittence of wind and solar resources. Because of increasing environmental problems, for example, greenhouse gas emission and energy cost have interested novel research into substitute methods in favour of electrical power generation. Maximum Power Point Tracking (MPPT) control method is a vast deal of novel research used for enhancing the efficiency of HRES. The authors have revealed that the hybrid techniques i.e. Global MPPT, fuzzy-neuro systems, Adaptive Neuro-Fuzzy Inference System (ANFIS), Perturbed and Observe (P&O) + Adaptive Neural Network (ANN) etc. can provide best results as compared to other MPPT control methods. This paper offering a state of art review of MPPT control techniques for HRES.     

用于单光子TOF测量的时间-幅度变换器

基于新型共源共栅电流源的积分方法,设计了一种用于单光子飞行时间(TOF)测量的时间-幅度变换器(TAC)。该方法有效简化了TAC电路结构,减小了TAC占用面积,显著提高了TOF的满量程范围(FSR)。采用0.18 μm标准CMOS工艺设计。集成TAC的单光子探测器像素单元的填充因子可达到26.8%。后仿真结果表明,该TAC在120 ns的FSR内具有230 ps的定时分辨率,微分非线性(DNL)低于0.05 LSB,积分非线性(INL)低于1.1 LSB。蒙特卡洛仿真表明,512个TAC像素间的不均匀性低于0.5 %。该TAC非常适用于高密度时间相关的单光子计数(TCSPC)探测器阵列。     

超宽带脉冲信号的光学生成方法研究

近年来超宽带(UWB)通信技术迅猛发展,在测量、雷达技术、民用和军事无线通信中有着重要的应用,UWB-over-fiber技术已经成为目前研究的热点,其中就包括UWB脉冲信号的产生方法。区别于传统的电子学方法,光子学产生方法不受电子瓶颈制约,可以实现很高的带宽,并且具有抗电磁干扰、重量轻、结构紧凑的优点。通过对比国内外本领域研究成果,讨论及总结了以下三种原理的UWB脉冲信号的光学生成方法:1)相位调制-强度调制转换(PM-IM);2)半导体光放大器(SOA)的非线性效应;3)频谱塑形和色散所致频域-时域映射,然后对各种方案进行了对比分析。     

Joint estimation of TOA and DOA in IR-UWB system using a successive propagator method

Impulse radio ultra-wideband (IR-UWB) ranging and positioning require accurate estimation of time-of-arrival (TOA) and direction-of-arrival (DOA). With receiver of two antennas, both of the TOA and DOA parameters can be estimated via two-dimensional (2D) propagator method (PM), in which the 2D spectral peak searching, however, renders much higher computational complexity. This paper proposes a successive PM algorithm for joint TOA and DOA estimation in IR-UWB system to avoid 2D spectral peak searching. The proposed algorithm firstly gets the initial TOA estimates in the two antennas from the propagation matrix, then utilises successively one-dimensional (1D) local searches to achieve the estimation of TOAs in the two antennas, and finally obtains the DOA estimates via the difference in the TOAs between the two antennas. The proposed algorithm, which only requires 1D local searches, can avoid the high computational cost in 2D-PM algorithm. Furthermore, the proposed algorithm can obtain automatically paired parameters and has better joint TOA and DOA estimation performance than conventional PM algorithm, estimation of signal parameters via rotational invariance techniques algorithm and matrix pencil algorithm. Meanwhile, it has very close parameter estimation to that of 2D-PM algorithm. We have also derived the mean square error of TOA and DOA estimation of the proposed algorithm and the Cramer-Rao bound of TOA and DOA estimation in this paper. The simulation results verify the usefulness of the proposed algorithm.     

多孔硅发光机制的分析

从量子力学的基本理论出发讨论了量子限制效应，推导出多孔硅有效禁带宽度增量并用量子限制效应和表面态及其物质在发光中作用的理论解释了ＰＳ光致发光的实验现象。