基于角加速率的MEMS陀螺仪快速标定方法

微机电系统(MEMS)陀螺仪的非线性误差是影响陀螺仪测量精度的主要因素之一。针对角速率标定法难以获得陀螺仪连续输出的问题。该文提出了一种角加速率标定实验方案,介绍了用二次标定方法解算出陀螺仪的零位误差系数、刻度因子、交叉耦合系数及非线性误差项的具体步骤。与常规补偿模型算法比较表明,此方法可快速标定陀螺仪的误差参数,补偿后的MEMS陀螺仪绝对误差小于0.084(°)/s,线性度提高了1~2个数量级。     

MEMS半球谐振陀螺的角速度积分及其FPGA设计

微电子机械系统(MEMS)半球谐振陀螺是MEMS微陀螺领域的研究热点,能工作在角速度积分模式下,具有体积小、质量轻、功耗低、成本低、对称性高、Q值高,以及精度高等优点.文章给出了一种微型半球谐振陀螺的结构,研究了其工作原理以及检测方法,设计了一种数字式MEMS半球谐振陀螺仪的角速度积分工作模式方案及其FPGA实现方法,以完成目前MEMS半球谐振陀螺的角速度积分模式的控制与检测工作.     

基于虚拟哥氏力的MEMS陀螺仪自标定方法及实验

本文提出了使用虚拟哥氏力来标定MEMS陀螺仪特性的一种方法,通过利用一系列电压信号来模拟哥氏力和角速率的输入,以获得陀螺仪的频率特性响应。该方法可以分别在开环模式和闭环模式的情况下便捷且高效的测量出陀螺的标度因数等性能指标。同时,该方法可以很容易识别外部角速度的动态响应,增大了传统标定方法的频率范围,避免了利用测试设备标定陀螺所面临的性能局限。并且,该方法可以用于微机械陀螺的误差校正和故障检测。本文所使用的陀螺是自主研制的双质量线振动陀螺。     

基于FPGA的数字闭环光纤陀螺仪模拟表头设计

光纤陀螺仪是一种用来测量角速度的传感器。为了检测调制解调电路是否符合设计要求,并提高陀螺的实际应用精度,本文设计了一种基于FPGA的光纤陀螺仪模拟表头及其测试系统,能有效地检测调制解调电路的性能。     

基于LABVIEW的MIMU 24项误差参数的快速标定方法

针对传统微惯性测量单元(MIMU)标定方法过程繁琐、标定周期长且标定设备复杂等问题,该文设计了一种通过LABVIEW上位机控制小型三轴转台对MIMU进行快速标定的一种方法。首先建立MIMU标定模型,再通过分别构建陀螺仪和加速度计的卡尔曼滤波器来减小运算量和标定时间。以小型三轴转台的姿态与速度为基准求得速度误差与姿态误差作为观测量,通过LABVIEW上位机控制三轴转台按照所设计好的标定路径转动,采集MIMU输出并使用卡尔曼滤波器LABVIEW的子函数（VI）进行MIMU的24项误差参数估计。实验结果表明,该方法能实现对MIMU中的陀螺仪和加速度计的快速标定,与传统分立式标定法相比,其安装误差与常值漂移的精度基本一致,标定因数相对误差小于0.006,标定时间由3 h减少至30 min。     

一种非设备方式对星敏感器进行精度标定的新方法

星敏感器是一种高精度的空间姿态敏感器,精度标定是保证其高精度测量效果中的重要一环.相对传统的采用测量仪器进行精度标定方式,作者提出了非设备方式对星敏感器进行精度标定的新方法.该方法无需外加精度测量设备,利用第二坐标系下的恒星坐标,换算出恒星角距,然后通过星敏感器对已知的恒星角距进行实际测量,从而标定出星敏感器的测量精度.实验数据证明,与传统方法相比,该方法具有更精确的标定效果.     

基于角速度估计的MEMS陀螺随机误差动态滤波方法

针对MEMS陀螺仪受随机误差影响较大需要进行滤波处理,采用时间序列分析法建立的随机误差模型无法直接用于动态条件下滤波的问题,提出了一种基于角速度估计的随机误差动态滤波方法.首先,采用时间序列分析法对MEMS陀螺仪随机误差进行分析与模型构建;然后,将角速度估计假设模型建模为三维线性模型,并与陀螺仪随机误差模型结合构建动态滤波模型;最后,采用强跟踪卡尔曼滤波方法直接估计出角速度值以实现对随机误差滤波,并进行试验验证.结果表明:无论是静态还是动态条件下,该滤波方法估计的角速度值精度均较高,可以有效降低MEMS陀螺仪的随机误差,提升MEMS陀螺仪精度.     

一种基于双轴位置转台的IMU快速标定方法

为了简化标定设备,降低标定成本,该文研究了利用双轴位置转台进行光纤陀螺惯组混合标定的可行性。通过分析加速度计和陀螺的标定原理,提出了一种快速六位置标定方案。利用地球重力加速度和自转角速度对加速度计和陀螺进行误差激励,完成标定。首先建立了标定模型,其次设计了位置编排方案,最后进行了实验验证。实验结果表明,快速六位置法能实现加速度计和陀螺误差参数的快速标定,其中标度因数的标定精度与传统方法基本一致,安装误差和常值漂移的精度相对于传统标定方法有所降低,但满足低精度的光纤陀螺惯组的使用要求;同时,与传统标定方法相比,其标定时间由4.5h减少至2h。     

MOAP方案治疗急性淋巴细胞白血病疗效观察

主要介绍了一种微机械系统(MEMS)陀螺仪的速率标定法,根据MEMS陀螺仪的输出数学模型,详细推导了如何得到MEMS陀螺仪的输出数学模型中的零漂、刻度因数和安装误差,并在得到其标定系数后将其封装在C函数中进行验证实验.通过实验数据分析可知,MEMS陀螺仪速率标定法原理简单,易于实现,且精度较高.此标定法所得到的MEMS陀螺仪输出数学模型能较准确地反映其输出,且MEMS陀螺仪的线性度有所改善.     

MEMS陀螺仪的一种实用标定法

主要介绍了一种微机械系统(MEMS)陀螺仪的速率标定法,根据MEMS陀螺仪的输出数学模型,详细推导了如何得到MEMS陀螺仪的输出数学模型中的零漂、刻度因数和安装误差,并在得到其标定系数后将其封装在C函数中进行验证实验.通过实验数据分析可知,MEMS陀螺仪速率标定法原理简单,易于实现,且精度较高.此标定法所得到的MEMS陀螺仪输出数学模型能较准确地反映其输出,且MEMS陀螺仪的线性度有所改善.     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

Nanoimprint Lithography -A Next Generation High Volume Lithography Technique

IntroductionNanoimprint Lithography is a well-acknowl-edged low cost, high resolution, large area pattern-ing process. It includes the most promising methods,high-pressure hot embossing lithography (HEL) [2],UV-cured imprinting (UV-NIL) [3] and micro contactprinting (m-CP, MCP) [4]. Curing of the imprintedstructures is either done by subsequent UV-lightexposure in the case of UV-NIL or by cooling downbelow the glass transition temperature of the ther-moplastic material in case of HEL…     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.     

Influence of PVK ： NPB hole transporting layer on the characteristics of organic light-emitting devices

A doping system consisting of NPB and PVK is employed as a composite hole transporting layer （CHTL）. By adjusting the component ratio of the doping system, a series of devices with different concentration proportion of PVK ： NPB are constracted. The result shows that doping concentration of NPB enhances the competence of hole transporting ability, and modifies the recombination region of charge as well as affects the surface morphology of doped film. Optimum device with a maximum brightness of 7852 cd/m^2 and a power efficiency of 1.75 lm/W has been obtained by choosing a concentration proportion of PVK ： NPB at 1：3.     

New insert layer structure OLEDs

An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn（salen）/Liq/LiF/A1. Effective insert electrode layers comprising LiF（1nm）/Al（5 nm） are used as a single semitransparent mirror, and bilayer cathode LiF（1 nm）/A1（100 nm） is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.     

Analysis of error performance on Turbo coded FDPIM

Due to variable symbol length of digital pulse interval modulation（DPIM）, it is difficult to analyze the error performances of Turbo coded DPIM. To solve this problem, a fixed-length digital pulse interval modulation（FDPIM） method is provided. The FDPIM modulation structure is introduced. The packet error rates of uncoded FDPIM are analyzed and compared with that of DPIM. Bit error rates of Turbo coded FDPIM are simulated based on three kinds of analytical models under weak turbulence channel. The results show that packet error rate of uncoded FDPIM is inferior to that of uncoded DPIM. However, FDPIM is easy to be implemented and easy to be combined, with Turbo code for soft-decision because of its fixed length. Besides, the introduction of Turbo code in this modulation can decrease the average power about 10 dBm, which means that it can improve the error performance of the system effectively.     

A method for calculating the center position of collimated light

It is a key problem to accurately calculate beam spots＇ center of measuring the warp by using a collimated laser. A new method, named double geometrical center method （DGCM）, is put forward for the first time. In this method, a plane wave perpendicularly irradiates an aperture stop, and a charge couple device （CCD） is employed to receive the diffraction-beam spots, then the geometrical centers of the fast and the second diffraction-beam spots are calculated respectively, and their mean value is regarded as the center of datum beam. In face of such adverse instances as laser intension distributing defectively, part of the image being saturated, this method can still work well. What＇s more, this method can detect whether an unacceptable error exits in the courses of image receiving, processing and calculating. The experimental results indicate the precision of this method is high.     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Preparation and Characterization of TaN ALD Precursors

High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET ＞ PDMAT ＞ TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.