一种高帧频EMCCD驱动电路设计

为满足自适应光学系统波前传感器需要高帧频、高灵敏度的要求,针对E2V公司的高帧频、低照度EMCCD 芯片CCD60设计了外围驱动电路.系统采用FPGA作为主要的逻辑控制和时序信号发生器件,采用EL7156管脚驱动器将TTL电平转换为CCD60需要的驱动电平,并用DDS(直接数字合成器)产生正弦波通过高压放大模块来产生高...     

利用光纤通信实现相机图像传输及控制

利用可编程逻辑器件FPGA控制高速串行通信器件CY7B923/933,将数字图像和控制指令 串行化,通过光电转换器件(HFBR-1119T/2119T)进行光纤数据传输,实现了对高帧频、多通道数字图像的远程传输和反馈控制。结果表明,该方法图像传输正确,控制稳定可靠,符合实际使用要求。     

用CPLD实现的高速数字图像存储转发装置

本文叙述了一种利用CPLD器件实现的高速数字图像存储转发装置,它被用于一个数字视频图像传输系统中.该装置的主要功能是将来自于CCD的数字图像数据存入大容量存储器中,并可以对数据进行编码,变换成PCM码输出.由于采用了VHDL语言设计,实现了分立器件难以实现的功能,提高了系统的可靠性,并可以方便地移植到各种CPLD器件中.     

高速科学CCD CAMERA系统设计

在实验结果的基础上,介绍了一种高速科学CCD相机系统设计。测试选用了柯达CCD芯片KAF-0401LE和KAF-1001E,用MAXII系列CPLD芯片实现了CCD驱动时序和数据采集时序控制;采用片内集成CDS的CCD信号A/D转换器AD9824进行相关双采样和高速模数转换;内置8051的CypressUSB2.0控制芯片CY7C68013A完成了高速同步数据传输及与上位机通讯,接收和发送上位机指令等;结合USB采集系统使用VisualC 编写了系统控制界面。实现了采集速率选择(最高10MHzPixelRate对应于20Mbyte/sUSB传输速度)、复合模式选择、单帧/连续采集、制冷温度采集和控制等,适用于同类型CCD相机的系统设计。     

高速多通道数据采集系统的设计

基于复杂可编程逻辑器件CPLD控制和USB网络动态增减接口,研究设计多通道高速高精度数据采集系统;CPLD作为主控系统,利用USB配置标记识别通道动态增减网路接口,搭建电子元器件设计采集控制核心电路,详细分析CPLD控制各个部件的时序采集和传输数据,给出USB动态增减网络通道接口的方法。成功设计探测速度可以达到80km/h,同时6个通道高速数据采集探测,并且每个通道采集的数据同时显示在同一屏幕上。     

基于SSD硬盘的嵌入式高速图像存储技术

高速大容量图像数据的存储技术是数字图像处理中的一项重要技术.为了实现图像数据的高速实时存储,提出了在嵌入式Linux平台上基于SSD硬盘的高速数字图像记录方法.采用Linux驱动程序控制SAS硬盘控制器,将图像数据高速记录在SSD硬盘上.介绍了整个系统结构,给出了Linux驱动程序的实现方法,分析了影响图像数据记录速度的因素.实验测试中图像数据记录速度可以达到150 MB/s,可以满足对高帧频相机的高速图像数据存储的要求.     

基于SRIO 的高速图像串行传输系统设计

针对CCD 图像具有分辨率高、数据量大的特点,本文提出一种新的平台,可实时完成数据采集,并将采集的数据通过SRIO 接口以3.125 Gb/s 的速度进行传输与显示.该方法根据SRIO 接口协议,采用FPGA+DSP 的方式,利用FPGA 内的高速串行通信接口MGT,实现SRIO 通信协议,与DSP 之间的SRIO 接口模块进行高速传输,再通过DSP 的网络接口将接收到的数据实时传输到PC 机,进行显示.实验结果表明,这种新的平台能够实时传输所采集的CCD 相机数据,并具有可靠性高,可移植性强,升级简单,易于工程实现的优点.     

多通道CCD图像数据实时记录系统

针对多通道CCD图像数据实时记录、预处理问题,本文提出了一种基于DSP并行处理技术的方案.实验结果表明,系统实现了多通道CCD图像数据的实时记录.用四片DSP以及一个通用CPU实现一个最小系统,用于实时记录六路CCD图像数据,同时实现图像数据和辅助数据的分离,处理结果可以记录在本地的磁盘,也可以通过网线完成数据的传输.最小系统安装在标准的CPCI机箱中,当输入通道数大于六路时,可以通过最小系统并行的方式,实现系统的扩展.该方案已经应用于18路CCD图像数据的实时记录系统中,最小系统实现了最高63.2MB/s的数据记录.     

基于CPLD的线阵CCD驱动的实现

本文以日本东芝公司的线阵CCD器件TCD1206SUP为例,在研究了线阵CCD器件工作原理和驱动电路波形的基础上,介绍了采用图形式层次设计方法,用复杂可编程逻辑器件(CPLD)设计线阵CCD驱动脉冲的实现方法。用一片EPM7064设计出TCD1206SUP正常工作所需的驱动波形,减小了驱动器的体积。讨论了电路的工作原理和设计特点,同时给出了电路原理图和CPLD电路的时序仿真波形。     

基于ARM的USB便携存储模块设计

介绍基于ARM控制CH375芯片实现的USB便携存储模块的设计。首先介绍USB便携存储模块原理，之后给出ARM控制CH375的具体硬件及软件设计，最后介绍USB便携存储模块在油气田井口数据实时检测及远程传输系统中的应用。利用该设计能够实现U盘自动提取采集数据，克服人工采集数据的周期长自然环境恶劣等困难，已成功应用到油气田数据采集领域。     

科学级CCD相机在星敏感器中的设计与应用

星敏感器通过探测天球上不同位置的恒星来确定航天器的姿态。星相机是星敏感器的成像系统。虽然近年来CMOS成像技术快速发展,但在科学级成像领域,特别是星敏感器应用中,CCD技术较成熟。本文的研究目的是研究一种探测能力强、数据更新快的用于星敏感器的成像系统。文中主要研究了基于TH7888A科学级CCD传感器的星相机的设计和应用,说明了CCD工作原理,详细分析了该种CCD传感器的星等探测灵敏度,论述了CCD星相机的设计方案。并用成像实验、动态范围测试、星等探测能力实验等实验验证了所设计的相机的性能。设计的星相机可以用给定的小型光学系统在60 ms以内的积分时间探测6等星,相机可达到10帧/秒的图像数据更新频率,满足短积分时间进行快速星光成像的要求。     

Centroid error analysis of Shack–Hartmann wave-front sensor induced by the sensitivity non-uniformity

Centroid error is the crucial limit to the performance of the Shack–Hartmann wave-front sensor. The previous studies showed that the centroid error was affected by the discrete sample, the photon noise and the readout noise of the CCD. For many special characters, a CMOS camera is also used in the Shack–Hartmann wave-front sensor. Compared to a CCD, the sensitivity of a CMOS camera is obviously non-uniform. In this paper, a detailed analysis of the centroid error induced by the sensitivity non-uniformity of pixels is presented. The theoretical results are represented and demonstrated through an experiment. The results show that the error induced by the sensitivity non-uniformity is only dependent upon the detector, and has no relationship with the other factors. For the CMOS camera mentioned in this paper, the centroid error is less than 0.015 pixels.     

电子倍增器件CCD60噪声特性分析

介绍EMCCD的增益原理,分析了EMCCD各种噪声的产生机理及相应的抑制方法,并推导出总信比噪模型,从该信噪比模型得出EMCCD相机的电子倍增过程大大削弱了读出噪声对探测灵敏度的影响;同时为保护电子倍增结构,在满足应用要求的前提下应尽量降低倍增增益;最后通过计算不同工作模式下CCD60的暗电流噪声和CIC噪声总和并以此...     

一种数字航测相机的驱动系统设计及优化方法

介绍一种应用于数字航测相机的大幅面CCD图像传感器驱动系统设计与开发,并详细分析了选用的FTF4052M芯片驱动时序和几种驱动方法。该系统采用增强型51单片机和CCD专用集成芯片结合的设计思路,研制出了大幅面全帧CCD的驱动电路。并从EMC的角度对电路进行降噪方面的优化,实现4008×5344高分辨率清晰图像的采集测试。结果表明该驱动系统的设计与优化方法能够实现对大幅面全帧CCD芯片FTF4052M的驱动,图像质量基本满足应用要求。     

Sensitivity enhancement of grating interferometer based two-dimensional sensor arrays using two-wavelength readout

Diffraction gratings integrated with microelectromechanical systems (MEMS) sensors offer displacement measurements with subnanometer sensitivity. However, the sensitivity of the interferometric readout may drop significantly based on the gap between the grating and the reference surface. A two-wavelength (2-λ) readout method was previously tested using a single MEMS sensor for illustrating increased displacement measurement capability. This work demonstrates sensitivity enhancement on a sensor array with large scale parallelization (~20,000 sensors). The statistical representation, which is developed to model sensitivity enhancement within a grating based sensor array, is supported by experimental results using a thermal sensor array. In the experiments, two lasers at different wavelengths (633 and 650 nm) illuminate the thermal sensor array from the backside, time-sequentially. The diffracted first order light from the array is imaged onto a single CCD camera. The target scene is reconstructed by observing the change in the first diffracted order diffraction intensity for both wavelengths. Merging of the data from two measurements with two lasers was performed by taking the larger of the two CCD measurements with respect to the reference image for each sensor. ~30% increase in the average sensitivity was demonstrated for a 160×120 pixel IR sensor array. Proposed architecture is also applicable to a variety of sensing applications, such as parallel biosensing and atomic force microscopy, for improved displacement measurements and enhanced sensitivity.     

Real-time tricolor phase measuring profilometry based on CCD sensitivity calibration

A real-time tricolor phase measuring profilometry (RTPMP) based on charge coupled device (CCD) sensitivity calibration is proposed. Only one colour fringe pattern whose red (R), green (G) and blue (B) components are, respectively, coded as three sinusoidal phase-shifting gratings with an equivalent shifting phase of 2π/3 is needed and sent to an appointed flash memory on a specialized digital light projector (SDLP). A specialized time-division multiplexing timing sequence actively controls the SDLP to project the fringe patterns in R, G and B channels sequentially onto the measured object in one over seventy-two of a second and meanwhile actively controls a high frame rate monochrome CCD camera to capture the corresponding deformed patterns synchronously with the SDLP. So the sufficient information for reconstructing the three-dimensional (3D) shape in one over twenty-four of a second is obtained. Due to the different spectral sensitivity of the CCD camera to RGB lights, the captured deformed patterns from R, G and B channels cannot share the same peak and valley, which will lead to lower accuracy or even failing to reconstruct the 3D shape. So a deformed pattern amending method based on CCD sensitivity calibration is developed to guarantee the accurate 3D reconstruction. The experimental results verify the feasibility of the proposed RTPMP method. The proposed RTPMP method can obtain the 3D shape at over the video frame rate of 24 frames per second, avoid the colour crosstalk completely and be effective for measuring real-time changing object.     

Research on the application of single camera stereo vision sensor in three-dimensional point measurement

A single camera stereo vision sensor model based on planar mirror imaging is proposed for measuring a three-dimensional point. The model consists of a CCD camera and a planar mirror. Using planar mirror reflections of a scene, a picture with parallax is obtained by shooting the target object and its virtual image. This is equivalent to shooting the target object from different angles with the camera and the virtual camera in the planar mirror, so it has the function of binocular stereo vision. In addition, the measurement theory of the three-dimensional point is discussed. The mathematical model of a single camera stereo vision sensor is established, the intrinsic and extrinsic parameters are calibrated, and the corresponding experiment has been done. The experimental results show that the measuring method is convenient and effective; it also has the advantages of simple structure, convenient adjustment, and is especially suitable for short-distance measurement with high precision.     

高分辨率便携式管道锈蚀检测仪

设计了一套高分辨率的便携式 X 射线管道锈蚀检测仪, 该检测仪成像空间分辨率为 3 lp/mm, 透度灵敏度为 1.6%. 在检测仪的设计过程中, 利用 CsI 转换屏将射线转换为可见光、利用微光慢扫描 CCD 相机成像, 在笔记本电脑的远程控制下, 由图像采集器获取射线数字图像并通过网络传输至笔记本电脑进行处理、显示和存盘等工作, 利用基于统计特性的自适应边缘增强次序滤波对管道锈蚀图像进行降噪增强处理, 取得了较好的效果. 实验结果表明, 该检测仪可清楚地显示管道内部结垢、堵塞、腐蚀等情况.     

动态波前相位的高分辨率测量

动态波前相位信息测量是大气光学，气动光学和激光技术等领域的重要实验手段。提出了一种具有高的时间和空间分辨率以及长的测量持续时间的动态波前相位测量方法。应用Ｈａｒｔｍａｎｎ－Ｓｈａｃｋ波前传感器获得高空间分辨率的相位信息，采用高帧频ＣＣＤ摄象机获得高时间分辨率图象数据。