超宽超窄矩形带通滤光片的设计

回顾了带通滤光片的研究应用现状,得出要设计超宽超窄的带通滤光片必须采用多腔串置的结构.引入了影响带通滤光片性能的参数,并对这些参数进行了分析.设计出了两类性能完全不同的带通滤光片,并对它们的特性做了一定的分析.     

超宽超窄矩形带通滤光片的设计

回顾了带通滤光片的研究应用现状,得出要设计超宽超窄的带通滤光片必须采用多腔串置的结构.引入了影响带通滤光片性能的参数,并对这些参数进行了分析.设计出了两类性能完全不同的带通滤光片,并对它们的特性做了一定的分析.     

双离子束溅射技术制备带通滤光片

研究了采用双离子束溅射沉积技术、以沉积时间作为膜厚控制手段制备带通滤光片的工艺。简要介绍了离子束溅射系统的基本工作原理和膜厚控制技术,描述了分别在K9玻璃和有色玻璃上制备由多层Ta2O5和SiO2薄膜组成的滤光片以及短波通和长波通的工艺过程,最后测试并分析了由短波通和长波通组成带通滤光片的光学性能。实验结果表明,采用双离子束溅射技术,以沉积时间作为膜厚监控手段能够制备出具有优良光性能并满足应用设计要求的带通滤光片。     

微型低温远红外带通滤光片的研制

论述了微型低温远红外带通滤光片的设计和研制。介绍了该滤光片不同于一般远红外滤光片的研制工艺。测试出了低温下该滤光片中心波长漂移参数，并给出和分折了校准后的测试结果。     

闪电探测用超窄带通滤光片的研制

根据闪电探测的需要,利用Anderson局域的概念,以SiO2和Ta2O5为介质材料,设计出了带通位置为闪电特征峰的超窄带通滤光片。统计结果显示,该滤光片的峰位、半峰宽和透过率受每层膜厚随机涨落的影响较小。通过ZZSX-800型真空镀膜机对所设计的膜系进行实际镀制,获得了性能优良的超窄带通滤光片。     

陷波滤光片的类褶皱设计

针对当前陷波滤光片设计方法中,因需要大量薄层和折射率连续渐变而导致的制作难度较高的问题,介绍了一种陷波滤光片的类褶皱膜系设计方法。此方法中,每层薄膜的层内折射率不变,层间折射率呈离散型渐变,每层为1个光学厚度,膜系模拟计算的光谱很好,并可降低制造工艺难度。给出了膜系的基本结构形式,并分析了其中各参数对陷波滤光片光谱的影响,指出了参数变化对光谱影响的基本规律。通过对典型膜系设计,模拟分析了膜厚偏差和折射率偏差对光谱的影响。结果表明,膜系对膜厚偏差更加敏感,为膜系镀制工艺中的误差控制提供了理论依据。     

采用亚微米埋入式光栅的彩色滤光片

为进一步提高彩色滤光片的色度性能和光能利用率,设计了一种宽带宽高透射率的亚微米埋入式光栅结构,该结构由PMMA基底、ZnS膜层、二维Al金属光栅和SiO2覆盖层等组成。采用严格耦合波理论分析了ZnS膜层厚度、周期、占空比等结构参数对透射光谱特性的影响,并在此基础上优化结构参数,获得了宽带宽滤波输出。当透射光谱中心波长为635,530和455nm时,相应透射效率分别为68%,78%和71%,半极大值处全宽(FWHM)约为100nm。计算结果表明,与其他应用于彩色滤光片的光栅结构相比,所设计光栅结构的中心光谱透射效率可提高19%,并有效减少了三色输出光谱之间的重叠区域,提高了彩色滤光片的色度性能。     

周期性渐变折射率光学薄膜的设计及光谱特性分析

分析折射率呈不同函数分布的周期性渐变折射率薄膜的光谱特性,分析表明光谱曲线具有负滤光片的特性。分别从最低和最高折射率、周期数、周期厚度的角度,对用共蒸法制备的周期性渐变折射率薄膜光谱特性进行了详细分析讨论。结果表明截止带中心波长和截止带宽度与周期厚度成线性关系,截止带中心波长的反射率与周期数成三次多项式关系。用堆叠和叠加两种方法设计渐变折射率多截止带负滤光片,并分析两种方法在共蒸法方式制备下的优缺点。最后总结出了渐变折射率负滤光片的设计方法。     

基于带通滤光片的平面工件面形干涉测量方法

针对目前工业领域对平面零件面形低成本测量需求,提出了一种基于带通滤光片的干涉测量方法。该方法根据分振幅干涉的原理,使用两个中心波长相差10 nm的滤光片分别放置在工业摄像头上,拍摄两组准单色光干涉图样,通过对比处理实现干涉条纹级数排序。然后使用Zernike多项式对完成排序的干涉图样进行拟合,获得环形工件面形,最后应用最小二乘法摆正,获得所测工件的面形精度信息。通过理论分析及实测对比验证了该方法的可行性。     

深背景高陡度荧光滤光片

荧光滤光片是应用于生物医学和生命科学仪器的关键元件。介绍了深背景、高截止陡度荧光滤光片的设计和镀制工艺。采用优化设计HB-βBPF膜系,提高荧光滤光片的隔离度。分析了散射对背景深度的影响,通过优化工艺参数,降低散射。研制的荧光滤光片截止陡度小于10nm(OD0.3~OD5的波长间隔),邻域背景达到OD7~OD8。     

减小表面粗糙度测量高斯滤波幅度偏差

提出了一种减小表面粗糙度测量用的高斯滤波器幅度传输特性偏差的新方法。根据中心极限定理,可以构造出不同的高斯逼近滤波器。用多级一阶巴特沃思滤波器和多级移动平均滤波器分别去逼近高斯滤波器时,两者的幅度偏差方向相反、极值位置相近,所以这两种方法的线性组合可以大大减小偏差。用这两种不同逼近滤波器的并联方法构成的一个简单的线性组合滤波器,去逼近高斯滤波器的幅度传输特性,其幅度传输特性的最大偏差只有0．11％。这种新的逼近方法,算法简单、精度高,实现了表面测量高斯滤波处理的高精度和高效率的高度统一。     

6自由度平台的Washout滤波器设计及试验研究

现代运动模拟器通常采用并联6自由度平台作为运动系统。由于平台的运动范围有限,就需要运用Washout滤波器,将实际运动转换成模拟器能够实现的信号。首先,设计经典Washout滤波器,对于高通加速度通道,平移和侧移方向都采用二阶高通滤波,升沉方向采用三阶高通滤波;倾斜协调通道纵向和侧向都选择二阶低通滤波器;高通角速度通道的3个方向都采用二阶高通滤波器。仿真证明Washout滤波算法能够提高模拟逼真度。然后,通过分析滤波器的自然响应频率和输出信号之间的关系,总结出Washout滤波器自然响应频率的选择原则。最后,在6自由度平台上针对所设计的滤波器进行试验。试验证明,所设计的Washout滤波器达到了预期的设计要求。     

Particle Filter for Estimation and Tracking

In recent years, the particle filter technique has been widely used in tracking, estimation and navigation. In this paper, the authors described several practical filters including the general practical, the extended Kaman practical, and the unscented particle filters. And they explained the degeneracy problem in the practical filter process, and introduced some solved methods. Finally they demonstrated the estimation of different particle filters in non-liner and non-Gaussian situation respectively. The result proved the unscented particle filter had the best performance.     

随动磨削曲轴表面异常轮廓误差去除方法

在高精度随动曲轴磨床中,为控制曲轴加工轮廓误差常采用预补偿的方法,如果测量时工件上有磨屑、毛刺等干扰将在测量结果中引入明显的异常轮廓,采用传统的高斯滤波器对数据进行处理将极大地影响轮廓误差的补偿精度,甚至导致废品出现。针对这一问题,给出了适用于闭轮廓的高斯滤波器、Rk滤波器和鲁棒高斯回归滤波器的理论模型。分别应用3种滤波器,对比分析结果可知,鲁棒高斯回归滤波器去除异常轮廓误差效果最理想,并通过人为改变异常轮廓的尺度,进一步验证鲁棒高斯回归滤波器的适应性和可靠性。该滤波方法集成到随动曲轴磨床软件中,实现异常轮廓的自动去除,提高了补偿效率,有效保证了曲轴磨削轮廓的误差精度。     

Optimal and near-optimal filters in high-resolution electron microscopy

Two filters for improving the visibility of crystalline material in the presence of amorphous surface contamination layers in high-resolution electron microscope images can be constructed automatically from the information present in the Fourier transform of the recorded image. The recorded signal is considered in the first approximation to be the sum of two signals which are uncorrelated in the frequency domain. By estimating the power spectrum of the signal from the amorphous layer, an optimized estimate for the desired signal is given by the Wiener filter. A second filter which uses the estimated amplitude of the amorphous signal to subtract out a background can be shown to be related to the Wiener filter. The two filters are applied to an experimental image of zeolite and the effects of the two filters are compared.     

The filtering method to calculate the transmission characteristics of the low-pass filters using actual measurement data

The Gaussian filter and spline filter are low-pass filters used in surface roughness estimation methods, and their transmission characteristics are well known. However, the transmission characteristics of the Gaussian filter and spline filter used at actual sites may not be in agreement with their theoretical characteristics. Generally, the spline filter is used with an open profile. Although the transmission characteristics of the periodic spline filter are well known, these transmission characteristics are not those of a nonperiodic spline filter used with an open profile. In the case of a Gaussian filter, the filter width of the theoretical transmission characteristics is ∞. However, a Gaussian filter of filter width λ_c is used at actual sites. This fact is a major problem. To solve this problem, it is necessary that the transmission characteristics of a low-pass filter are obtained from actual measurement data and the filter output. However, it is not possible to calculate the transmission characteristics from actual measurement data owing to the end effect and the discontinuity at each end of the data, etc. In this paper, we propose a new method for exactly calculating the transmission characteristics of a low-pass filter. This method involves the process in which the open profile is considered as a closed profile by repeating it periodically. The transmission characteristics of a nonperiodic spline filter and a Gaussian filter (filter width λ_c) used at actual sites were confirmed by the proposed method. The transmission characteristics of the Gaussian filter of filter width λ_c were almost the same as the theoretical characteristics. However, the transmission characteristics of the nonperiodic spline filter were considerably different from those of a periodic spline filter with well-known characteristics. Moreover, the transmission characteristics of the nonperiodic spline filter were found not to be unique.     

新型TCG数码相机编码滤色器研究

在分析三色光栅(TCG)编码滤色器用于数码彩色摄影原理的基础上，完成了黑白CCD像面前加贴TCG编码滤色器获得数字彩色图像的实验。通过对三种编码滤色器的结构分析说明TCG编码滤色器具有提高图像分辨率的潜力。采用TCG和Bayer网格两种编码滤色器进行软件仿真获得彩色图像，这两种图像的对比说明TCG编码滤色器具有彩色还原性好的优点，可形成新型数码相机的基础。     

两种空气过滤器的性能比较及改进措施

本文对两种空压机机前过滤器进行了简要介绍,并分别从过滤效果、使用寿命、吸风口、大气环境和滤料等方面的特性进行了比较分析,最后对自洁式过滤器使用中出现的问题提出了维护办法.     

射频系统中MEMS谐振器和滤波器

介绍了目前国内外射频系统中所涉及的静电梳状谐振器、自由梁谐振器、薄膜声体波谐振器、腔结构谐振器、平行谐振器结构HF带通滤波器、折叠梁MF滤波器、分布传输线可调滤波器等MEMS谐振、滤波器件.对这些器件的结构原理、制造方法以及性能指标作了分析.把这些器件的性能指标和目前射频系统中谐振器、滤波器的性能要求进行比较,分析了这些器件的应用前景.最后,对基于MEMS技术的射频谐振器、滤波器发展作出展望.     

NONLINEAR ESTIMATION METHODS FOR AUTONOMOUS TRACKED VEHICLE WITH SLIP

In order to achieve precise,robust autonomous guidance and control of a tracked vehicle,a kinematic model with longitudinal and lateral slip is established,Four different nonlinear filters are used to estimate both state vector and time-varying parameter vector of the created model jointly.The first filter is the well-known extended Kalman filter.The second filter is an unscented version of the Kalman filter.The third one is a particle filter using the unscented Kalman filter to generate the importance proposal distribution.The last one is a novel and guaranteed filter that uses a linear set-membership estimator and can give an ellipsoid set in which the true state lies.The four different approaches have different complexities,behavior and advantages that are surveyed and compared.