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脉冲激光测距中时间间隔测量的新方法 总被引:1,自引:3,他引:1
提出脉冲激光测距中时间间隔测量的新方法。传统数字法的测时误差主要是开始和结束2个脉冲周期的计数误差,为此利用FPGA芯片中集成锁相环(PLL)单元产生N路同频且相位均匀分布的时钟脉冲,用N个计数器在这2个周期进行计数,用计数结果均值作为最终结果。这相当于将脉冲周期T细分为N等份,每份相当于1个脉冲,其周期为T/N。实现了在不增加测量时间和盲区的前提下,测量精度提高了N倍,解决了传统脉冲激光测距系统中提高精度、缩短测量时间和盲区的矛盾。 相似文献
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高精度时间测量技术在激光测距中有着重要作用,而时钟信号周期误差是影响时间测量精度的关键。传统的时钟周期校准往往只将测量过程中最后一个时钟周期的误差作为校准参数,无法对整个测量过程中的误差进行补偿。针对这一问题,提出了脉冲激光测距中高精度时间测量时钟信号误差补偿的方法,通过测量计时芯片在不同时间下的时钟周期误差,构造误差曲线以对测量结果进行补偿,提升了时间测量系统的测量精度。使用TDC-GP22专用计时芯片设计了时间测量系统并进行了测试。测试结果表明,系统平均绝对误差为0.38 ns,最小误差可达到65 ps。 相似文献
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自触发脉冲激光测距飞行时间测量研究 总被引:1,自引:0,他引:1
提出一种新型脉冲激光测距方法——自触发脉冲飞行时间激光测距方法。运用该方法有效解决了传统脉冲激光测距法中存在的提高测量精度和缩短测量时间两者之间的矛盾。对该方法及本质特点进行了详细描述和理论分析,并给出用于描述该方法的基本方程。其飞行时间测量系统的设计很大程度上决定了自触发脉冲激光测距的测量精度和测量速度。设计并实现了基于CPLD的自触发脉冲激光测距飞行时间测量系统。CPLD的使用提高了测量精度,并且结构简单,体积小,可靠性高,非常适合高性能便携式的激光测距仪。 相似文献
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《电子科技文摘》2006,(9)
0622873 0.35μm脉冲激光辐照铝平面靶软X射线转换效率测量=Measurement of conversion efficiency of soft X-ray from 0.35μm laser-irradiated aluminum planar targets [刊,英]/任树喜//上海大学学报(英文版).—2006,10 (3).—224-227(E) 0622874光学层析成像在含空洞状区域的图像重建[刊,中]/孟静//激光与红外.—2006,36(6).—515-518(G)文章给出一种直接基于传输模型的含空洞状区域的重要方法。实验证明,在传输模型下,不需要知道空洞状区域的位置、大小等信息即可成功重建光学层析图像。参12 0622875并行计数法脉冲激光测距的研究[刊,中]/黄震//激光与红外.—2006,36(6).—431-432(G)提出脉冲激光测距中利用并行计数法测量时间间隔。传统数字法测时误差主要是开始和结束两个脉冲周期的计数误差。为此利用CPLD高速缓冲的延迟特性产生多路同频且相位均匀分布的时钟脉冲,用多个 相似文献
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CPLD在自触发脉中激光测距飞行时间测量中的应用 总被引:1,自引:0,他引:1
自触发脉冲激光测距是一种新型的脉冲激光测距方法,该方法解决了传统脉冲激光测距测量精度与测量速度之间的矛盾.其飞行时间测量系统的设计很大程度上决定了自触发脉冲激光测距的测量精度和测量速度.设计并实现了基于CPLD的自触发脉冲激光测距的飞行时间测量系统.CPLD的使用提高了激光测距的精度,并且系统结构简单,体积小,可靠性高,非常适合高性能手持式脉冲激光测距仪.对自触发脉冲激光测距进行了实验研究,在20 m的测量范围内,获得了±0.98 mm的测距精度. 相似文献
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An accidental coincidence is defined as the erroneous registration of two photons, originating from separate positron annihilations, as having originated from the same positron annihilation. Previous analyses which did not consider accidental coincidences indicated that for a certain radioactivity distribution a gain in image signal-to-noise ratio of about 5 dB is achieved by the time-of-flight method over the conventional method. Subsequent experiments have validated this prediction in low counting rate situations. For higher, typical counting rates these experiments showed a significantly larger gain of about 9 dB, which was attributed to the way in which the time-of-flight method suppresses the degrading effects of accidental coincidences. We present an analytical model, extended from a previous model, which considers accidental coincidences. Calculations of signal-to-noise ratio, using this model, compare well with the experiments and show that the additional gain is indeed due to the treatment of accidental coincidences. An understanding of the model leads to an intuitive explanation of the gain mechanism and a determination of an effective coincidence-timing window that is achieved by the time-of-flight method. 相似文献
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基于飞行时间法的纳秒量级时间间隔测量系统研制 总被引:1,自引:0,他引:1
为了更好地探测空间等离子体成分,研究了一种基于飞行时间法的纳秒量级时间间隔测量系统,分别介绍了该系统的三个组成部分CPU模块、时间间隔测量模块、数据传输模块。并着重研究了纳秒量级时间间隔的测量方法,详细介绍了主要时间间隔测量芯片TDC-GP1。并对数据传输模块的设计做了简要说明。实验结果表明,该测量系统的性能可满足探测需求。 相似文献
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多惯组脉冲输出同步计数系统设哥 总被引:1,自引:0,他引:1
为满足某惯导设备生产厂家对多个惯组产品进行同时测试的需求,设计了一种对于多路脉冲信号同步计数的测试系统。(方法)测试系统以FPGA芯片和USB芯片CY68013N核心,对4个惯导组件输出的48路脉冲信号.每路进行无缝计数,每4ms为一个计数单元。并利用USB总线将每一个计数单元的计数值上传到测控计算机,上位机程序进行实时的处理、保存和显示。(方法)测试系统满足了对多个惯组产品同时测试的要求,提高了测试效率。 相似文献
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David Stoppa Lucio Pancheri Mauro Scandiuzzo Lorenzo Gonzo Gian-Franco Dalla Betta Andrea Simoni 《IEEE transactions on circuits and systems. I, Regular papers》2007,54(1):4-12
A 64-pixel linear array aimed at 3-D vision applications is implemented in a high-voltage 0.8 mum CMOS technology. The detection of the incident light signals is performed using photodiodes biased above breakdown voltage so that an extremely high sensitivity can be achieved exploiting the intrinsic multiplication effect of the avalanche phenomenon. Each 38times180-mum2 pixel includes, besides the single photon avalanche diode, a dedicated read-out circuit for the arrival-time estimation of incident light pulses. To increase the distance measurement resolution a multiple pulse measurement is used, extracting the mean value of the light pulse arrival-time directly in each pixel; this innovative approach dramatically reduces the dead-time of the pixel read-out, allowing a high frame rate imaging to be achieved. The sensor array provides a range map from 2 m to 5 m with a precision better than plusmn0.75% without any external averaging operation. Moreover, with the same chip, we have explored for the first time the implementation of an indirect time-of-flight measurement by operating the proposed active pixel in the photon counting mode 相似文献
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Machida H. Ando H. Yasuda K. Furutani K. Yamashita Y. Nakashima H. Takeda Y. Nakajima K. Sakao M. Nakaya M. 《Solid-State Circuits, IEEE Journal of》1993,28(3):344-351
The authors present three VLSI chips-a processor (PU) chip, a cache memory (CU) chip, and a network control (NU) chip-for a large-scale parallel inference machine. The PU chip has been designed to be adapted to logic programming languages such as PROLOG. The CU chip implements a hardware support called `trial buffer' which is suitable for the execution of the PROLOG-like languages. The NU chip makes it possible to connect 256 processing elements in a mesh network. The parallel inference machine (PIM/m) runs a PROLOG-like network-based operating system called PIMOS as well as many applications and has a peak performance of 128 mega logical inferences per second (MLIPS). The PU chip containing 384000 transistors is fabricated in a 0.8 μm double-metal CMOS technology. The CU chip and the NU chip contain 610000 and 329000 transistors, respectively. They are fabricated in a 1.0 μm double-metal CMOS technology. A cell-based design method is used to reduce the layout design time 相似文献
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人工神经网络是现代信息处理领域的一个重要的方法。相对于软件实现 ,硬件实现方式能充分发挥神经网络并行处理的特点。用模拟电路实现神经网络电路形式简单、功耗低、速度快、占用芯片面积小 ,可以提高在神经网络芯片上神经元的集成度 ,神经元电路适合用模拟电路实现。文中综述了当前神经网络单元的模拟 VLSI实现的成果、新技术以及作者的工作成果。针对应用最广泛的线性和平方突触神经元 ,详细从权值存储单元、突触电路和阈值函数电路三方面来叙述。对各种实现方式的优缺点进行了比较 ,同时指出了神经网络实现电路中需要考虑的因素。最后 ,展望了用集成电路技术实现自学习神经网络的发展方向 相似文献