基于Linux的嵌入式实时视频跟踪系统

将ARM与DSP相结合,设计并实现了一套嵌入式实时视频传输跟踪系统;该系统以集成ARM和DSP双内核的OMAP3730作为核心处理器,首先通过ARM上搭载的Linux操作系统实现基于V4L2的图像采集功能,然后调用DSP完成H.264视频编码,压缩后的图像由基于实时流传输协议的流媒体服务器传输至远程计算机端解码并显示,最后利用camshift跟踪算法实现对运动目标物体的实时跟踪。该系统是小型无人机自主导航与控制的视觉导航以及以无人机为平台的运动目标检测的基础,有很好的应用前景。     

基于ARM和DSP的双核嵌入式视频监控系统

针对传统嵌入式视频监控设备集成度低,功能有限,响应速度慢,计算能力不足的问题,研究了一种基于ARM微处理器S3C6410与TMS320DM642 DSP双核体系结构的嵌入式视频监控系统。该系统采用CMOS摄像头采集视频数据,经DM642上算法处理后通过HPI高速并行接口传输给ARM处理器,ARM处理器负责对接收到的视频进行控制和LCD显示。重点阐述了ARM和DSP系统单元间的硬件连接方案,HPI接口驱动程序的设计实现,以及结合Linux异步通知和多线程技术的QT/Embedded客户端人机交互软件的编写。最后,移植了运动目标跟踪算法到DSP中并对整个系统进行实验测试,验证系统的性能。经实验证明,所设计的系统稳定可靠,视频清晰流畅,具有性能高、功耗和成本低、可扩展性强等优点,在嵌入式视频监控领域具有推广和使用价值。     

一种改进型的高解析喷码机控制系统的设计与实现

设计了一种以ARM9处理器和Windows CE操作系统为核心的改进型高解析喷码机控制系统。硬件上,采用绝对式光电编码器检测待喷物体的移动速度,提高检测精度;同时增加了喷头喷印速度的自动调节功能;摄像头模块实现了实时监控喷码机工作情况的目的。软件上,以S3C2440处理器的BSP包为基础,进行源代码的移植开发工作,应用到喷码机平台。硬件电路的设计完善了整个喷码机系统,软件程序的设计维护了喷码机系统的正常运行。实验测试结果证明,此系统满足高性能的要求,完成设计目标。     

基于模块计算机的千兆网磁共振谱仪控制接口

提出了一个基于模块计算机的磁共振谱仪的控制接口,它建立了核磁共振成像谱仪与上位计算机之间的通信,实现了控制谱仪、上传和下载、数据处理等功能,具备较高的传输速度,以及较好的实时性. 该接口以硬件模块的方式集成到谱仪上,通过千兆和百兆以太网连接上位机,接收下传至谱仪的序列;用中断机制和直接内存存取(DMA)方式实现与谱仪的数据传输,并将处理采集到的回波数据并上传到上位机. 控制接口的设计采用模块计算机Computer-On-Module(COM)的设计思路,以高性能的处理器为嵌入式平台,在Linux操作系统下开发驱动程序和应用程序. 实验证明,该模块具有数据处理速度快、传输速率高,成本低,体积紧凑,扩展性强等特点,是实现磁共振谱仪高性能的控制接口的理想方案.     

基于嵌入式的工业控制人机界面系统研究

针对工业控制系统网络化和良好人机交互性的需求,构建和开发了基于ARM9微处理器的通用工业控制人机界面系统。硬件部分主要讨论了以S3C2440微处理器为核心的硬件电路设计,外围电路模块包括SDRAM及Flash存储器电路、以太网电路、RS-232/RS-422电路、触摸屏及LCD接口等电路,在分析了硬件系统信号完整性的前提下,完成了6层PCB的设计工作。软件部分主要研究了U-Boot移植和内核裁剪技术,编写了相关的硬件设备驱动程序,设计了基于QT/Embedded的人机界面和相关应用程序。论文研究最终实现了工业控制系统的人机交互和控制需求。     

基于OMAPL138和FPGA构架的PC104主板检测系统

为了对PC104主板进行自动检测,分析了PC104主板工作原理及其总线时序,提出了一种基于ARM+FPGA的嵌入式检测系统的设计方案;该方案采用德州仪器(TI)双核架构的高性能芯片OMAPL138中的ARM核来实现检测系统的应用管理,DSP核实现数据的处理,并利用FPGA技术来实时采集PC104总线数据;检测系统在Linux操作系统下,通过人机交互方式实现了PC104主板的各种功能的自动检测;实验结果显示该检测快速可靠,为PC104主板的自动检测提供了一种有效的方法。     

基于ARM Cortex-M3的某新型装备信息采集系统设计

根据某新型装备特点,介绍了一种基于ARM Cortex-M3和SD卡的数据采集系统的硬件设计和软件设计。硬件部分包括信号调理电路、微控制器外围电路和SD卡接口电路三个方面。其中微控制器是基于ARM Cortex-M3微处理器设计的STM32F205VG,本设计采用微控制器自带的ADC模数转换器完成模数转换。软件部分包括系统软件和应用软件两部分,其中系统软件主要有主程序模块、初始化程序模块等;应用软件主要有信息采集、SD卡读写程序等。本系统设计采用ARM微处理器,充分利用了ARM的低功耗、高效率、体积小的优点,具有广泛的应用前景。     

基于OMAPL138 FPGA构架的PC104主板检测系统

为了对PC104主板进行自动检测,分析了PC104主板工作原理及其总线时序,提出了一种基于ARM FPGA的嵌入式检测系统的设计方案。该方案采用德州仪器(TI)双核架构的高性能芯片OMAPL138中的ARM核来实现检测系统的应用管理,DSP核实现数据的处理,并利用FPGA技术来实时采集PC104总线数据。检测系统在Linux操作系统下,通过人机交互方式实现了PC104主板的各种功能的自动检测。实验结果显示该检测快速可靠,为PC104主板的自动检测提供了一种有效的方法。     

基于DaVinci平台的桶标在线双目识别系统设计

为解决工业生产线灌装桶标在线识别,避免人工检测的疏失、降低工作量,提出并实现基于DaVinci平台和嵌入式图像检测技术的桶标在线识别系统,该系统采用双核处理器OMAP3530对运动桶标图像进行处理,并采用双摄像头、双处理器的双目并行处理架构解决灌装桶在生产线上不规则旋转识别,提出的嵌入式图像识别及融合决策算法克服了工业现场光线变化大、不规则背景扰动等干扰影响,经过现场2 000次随机试验,无漏识和错识虚警,仅存在部分因桶标遮挡、污损导致未识别,总识别率达到99.81%,满足实际使用要求。     

基于软件无线电架构的手持式频谱仪硬件设计

以手持式频谱仪为背景,设计一种基于软件无线电架构的、高集成度的、低功耗的手持频谱测量平台。该平台采用Xilinx公司28nm高性能功耗比Spartan 7序列的FPGA芯片XC7S100和TI公司集DSP和ARM为一体的双核CPU芯片OMAP-L138为主处理器,选用低功耗、高宽温、自身发亮的AMOLED屏为人机交互模块,通过EMIFA、UPP等外部拓展接口及强大的数据处理能力,结合时钟、电源模块,形成了并行与浮点计算优势互补的手持式数字信号处理系统,解决了频谱仪中频、零频信号的并行处理及复杂的浮点模型解算问题,该系统能具有体积小、精度高、高性能功耗比等特点,在户外等测试现场具有广泛的运用前景。     

Self-organization of five species in a cyclic competition game

Cyclic competition game models, particularly the “rock–paper–scissors” model, play important roles in exploring the problem of multi-species coexistence in spatially ecological systems. We propose an extended “rock–paper–scissors” game to model cyclic interactions among five species, and find that two of the five can coexistent when biodiversity disappears, which is different from the “rock–paper–scissors” game. As the number of fingers is five, we named the new model the “fingers” game, where the thumb, forefinger, middle finger, ring finger, and little finger cyclically dominate their subsequent species and are dominated by their former species. We investigate the “fingers” model in two ways: direct simulations and nonlinear partial differential equations. An important finding is that the number of species in a cyclic competition game has an influence on the emergence of biodiversity. To be specific, the “rock–paper–scissors” model is in favor of maintaining biodiversity in comparison with the “fingers” model when the variables (population size, reproduction rate, selection rate, and migration rate) are the same. It is also shown that the mobility and reproduction rate can promote or jeopardize biodiversity.     

Contrastive analysis on tone between Putonghua and Taiwan Mandarin

The differences of the pitch and duration of Chinese syllables between Putonghua （PTH） and Taiwan Mandarin （TM） were studied. The speech materials to be used are not only isolated syllables, but also sentences. The results reveal that： For the isolated syllables, T1 and T2 in TM are influenced by Minnan dialect, therefore their pitch are lower than those in PTH. T3 is fall-rise in PTH, while it is fall in TM. Moreover, the syllable duration sequence for different tone is T3〉T2〉T1〉T4 in PTH, while it is T1〉T2〉T3〉T4 in TM. For the syllables in sentences, T2 is mid-rise in PTH, while it is mid-level in TM. And the T3 is longer than T4 but shorter than T1 or T2 in PTH, while it is the shortest in TM. Furthermore the effects of prosodic phrase boundary on duration for different tones are almost the same in PTH, but the lengthening part of T1 or T2 is longer than that of T3 or T4 in TM.     

Experimental study on downstep in Chinese intonation

Downstep in pitch contour of Chinese Putonghua is examined using subtly designed sentences by controlling tone combinations. The results show both automatic and nonautomatic downstep phenomena exist in Chinese. In non-automatic downstep, low tones compress downwards the pitch range of the following syllables. and the main influence of downstep is on topline. Low tone not only lower the topline behind it, but also raise the high tones before it, the effects are compatible with each other. In automatic downstep, the topline of pitch contour in intonational phrase is presented as a linear downtrend, but it differs among speakers due to the effect of personal stress practice. In comparison with downstep phenomenon in other tone or non-tone languages, the downstep ratio in Chinese is not constant, and the domain of downstep is not limited within the adjacent tones.     

Abelian-Higgs phase of SU(2) QCD and glueball energy

It is shown that SU(2) QCD admits an dual Abelian-Higgs phase, with a Higgs vacuum of a type-Ⅱ superconductor. This is done by using a connection decomposition for the gluon field and the random-direction approximation. Using a bag picture with soft wall, we presented a calculational procedure for the glueball energy based on the recent proof for wall-vortices [Nucl. Phys. B 741(2006)1].     

Theoretical analysis and simulation of conjugate heights for dual-conjugate AO system in lidar

A multi-conjugate adaptive optics （MCAO） can offer a possibility of widening field of view （FOV） characterized by the isoplanatic angle, and the choose of conjugate height becomes a basic problem for MCAO, which influences the size of iosplanatic angle. Considering the application of lidar, the isoplanatic angle＇s expressions of two deformable mirrors （DMs） MCAO for uplink and downlink are deduced. The effects of conjugate heights for dual-conjugate AO are thoughtfully discussed, and the isoplanatic angles are further analyzed. The results show that the isopanatic angle varies with the conjugate height and reaches the maximum as the conjugate height is at the optimal altitude. Moreover, the optimal conjugate height changes with the propagation distance.     

Quick single-photon detector with many avalanche photo diodes working on the time division

Due to the limit of response speed of the present single-photon detector, the code rate is still too low to come into practical use for the present quantum key distribution (QKD) system.A new idea is put up to design a quick single-photon detector.This quick single-photon detector is composed of a multi-port optic-fiber splitter and many avalanche photo diodes (APDs).Au of the ports with APDs work on the time division and cooperate with a logic discriminating and deciding unit driven by the clock signal.The operation frequency lies on the number N of ports, and can reach N times of the conventional single-photon detector.The single-photon prompt detection can come true for high repetition-rate pulses.The applying of this detector will largely raise the code rate of the QKD, and boost the commercial use.     

Signal generation in an isotropic medium in scanning electron acoustic microscope

Based on the research in Ref. [5][Materials Science and Engineering, 1989; A122： 57 63], an improved model of heat source is set up, the different modes of Lamb wave in an isotropic sample generated by a chopped electron beam at frequency f are obtained with integral transform and normal function expansion method, and the output signal of PZT coupled at the back surface of the sample is found out. The generation mechanism of SEAM （Scanning Electron Acoustic Microscopy） signal is discussed. It shows that the SEAM is a near field imaging technique with high spatial resolution and its best lateral spatial resolution is about 2√2α （α is the radius of the focused electron beam）. Some of experimental results of SEAM images are presented in the paper and it shows that the spatial resolution of SEAM is better than 0.5 μm and smaller than the thermal diffusion length of the sample. Therefore the character of near field imaging in SEAM is also proved experimentally.     

High efficiency filtering using two-dimensional photonic crystal coupled cavity structures

Transmission spectra of coupled cavity structures (CCSs) in two-dimensional (2D) photonic crystals (PCs) are investigated using a coupled mode theory, and an optical filter based on CCS is proposed. The performance of the filter is investigated using finite-difference time-domain (FDTD) method, and the results show that within a very short coupling distance of about 3λ, where λ is the wavelength of signal in vacuum, the incident signals with different frequencies are separated into different channels with a contrast ratio of 20 dB. The advantages of this kind of filter are small size and easily tunable operation frequencies.