基于改进小波变换的MEMS陀螺信号去噪算法

为提高MEMS陀螺仪测量精度,抑制测量噪声对其造成的影响,该文分析了某型号MEMS陀螺仪误差特性,提出基于递归最小二乘法(RLS)多重小波分解重构的强追踪自反馈模型,建立新的软阈值函数。由于模型处理后的数据带有部分奇异值,该文提出了一种改进的中值滤波算法。对于陀螺仪零偏噪声问题,提出零偏不稳定性抑制算法,并对该算法模型进行了详细的描述。将某项目研究中列车姿态测量系统的实验数据应用到该算法模型中。测试实验分为静态、动态两组,其结果均表明:该算法减小了信号中的噪声,有效地抑制了MEMS陀螺仪随机漂移,提高了姿态解算的精度。肯定了该算法对陀螺仪输出信号噪声去除,以及使用精度提升的可行性和有效性。     

多传感器滤波算法下的两轮自平衡机器人控制

文中旨在实现两轮自平衡机器人更加稳定的姿态控制的研究,选择STM32作为开发平台,针对在对两轮平衡车姿态检测过程中存在一定的噪声干扰和测量误差的问题,设计了一种基于卡尔曼滤波的由多个传感器数据融合的方法。在更好地融合了多组陀螺仪与加速度计的数据,同时减少了存储量,得到更准确更稳定的角度值。控制结果表明,卡尔曼滤波方法下的多组传感器数据融合的姿态检测方案,能够更好地有助于系统抑制噪声,使得自平衡机器人的姿态调节更加稳定,更有利于机器人系统的控制。     

基于MEMS微惯性器件的姿态测量 单元设计与测试

MEMS惯组具有体积小、价格低、易于集成等优点,已被广泛应用于各个领域,为提高MEMS姿态解算精度,采用 Mahony互补滤波方法设计了MEMS惯性组件,Mahony互补滤波器将陀螺仪解算的高频姿态信号和加速度计－磁强计解算的低频姿态信号进行融合,提高测量精度,介绍了MEMS惯组硬件、软件、算法设计及无磁转台测试,无磁转台静态测量下的俯仰角精度0.51°,横滚角精度 0.5°,航向角精度1.1°。     

基于AHRS的改进自适应互补滤波算法研究

针对基于MEMS传感器的航姿参考系统精度不高、数据易漂移导致测量无人载体航姿数据不准确的问题,设计了基于四元数与自适应互补滤波相结合的改进自适应互补滤波算法。通过对MEMS加速度计与磁强计输出数据、MEMS陀螺仪的积分数据进行补偿、数据融合,减小积分漂移。仿真实验数据表明,该改进互补滤波算法可抑制外部噪声对输出数据准确性的影响,提高了姿态角输出数据准确性。     

微型姿态方位参考系统的设计

微型姿态方位参考系统基于stm32单片机和MEMS传感器的实时姿态测量系统。由stm32通过iic总线采集陀螺仪、加速度计、电子罗盘原始数据,利用互补滤波算法进行数据融合,采用四元数进行姿态更新并通过串口或spi总线实时输出姿态数据。     

基于MEMS惯性传感器的两轮自平衡小车设计

着重分析了两轮自平衡小车的设计原理与控制算法,采用卡尔曼滤波算法融合陀螺仪与加速度计信号,得到系统姿态倾角与角速度最优估计值,通过双闭环数字PID 算法实现系统的自平衡控制。设计了以MPU-6050传感器为姿态感知的两轮自平衡小车系统,选用8位单片机HT66FU50A为控制核心处理器,完成对传感器信号的采集处理、车身控制以及人机交互的设计,实现小车自主控制平衡状态、运行速度以及转向角度大小等功能。     

基于卡尔曼滤波的两轮自平衡车姿态检测研究

在两轮自平衡车设计的过程中,车身姿态检测是关键的设计环节,关系到自平衡车能否有效进行车身的自动控制。但是,使用单一传感器容易导致姿态检测过程中出现测量误差和噪声干扰,所以还需要对测量信号进行滤波处理。因此,基于这种情况,本文设计了一个基于卡尔曼滤波的两轮自平衡车姿态检测系统,从而更好的解决自平衡车的姿态控制问题。     

基于MARG传感器的头部姿态解算方法研究

针对头盔显示器(HMD)的头部姿态检测系统中单一传感器进行头部姿态解算准确度低、精度粗略的问题,提出了一种基于MARG传感器的头部姿态解算方法。将互补滤波与PI算法相结合估算陀螺仪的漂移误差,再通过扩展卡尔曼滤波(EKF)实现姿态数据融合。设计了由CC1310、陀螺仪、加速度计和磁强计组成的头部姿态检测单元进行测试实验。与单独的EKF对比,结果表明,这种算法对陀螺仪自身的漂移和加速度计噪声有抑制作用,提高了头部姿态解算的精度和稳定性。     

一种基于AIKF的姿态测量算法

惯性测量单元中传感器具有较强的非线性和噪声的不确定性,导致使用常规卡尔曼滤波时误差大,容易出现发散,针对此问题,该文提出了一种改进的自适应增量卡尔曼滤波（AIKF）算法。该算法使用互补滤波将加速度计、磁力计和陀螺仪的数据进行融合,利用滤波后的数据增量作为卡尔曼滤波器的观测量,同时对系统噪声进行自适应在线估计,以获得精准的姿态输出。实验结果表明,该算法能够实现姿态的精准测量,摇摆台试验中俯仰角、横滚角误差小于0.05°,航向角误差小于0.15°,具有较好的噪声抑制能力。     

基于线性CCD的两轮自平衡智能小车控制系统设计

文中设计了一种基于线性CCD图像传感器的两轮自平衡智能小车。该车通过加速度计测量小车倾角和陀螺仪测量车的倾角速度,两个数据融合得到车的姿态,进而控制其自身平衡,通过线性CCD检测赛道的信息实现行走及转向.经实验验证,该智能小车系统稳定,鲁棒性强,符合我们设计的要求。     

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.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.