Damage Detection of Composite Material Intelligent Structure with a New Photoelectric System

A kind of photoelectric system that is suitable to measuring and to testing the damage of the composite material intelligent structure was presented. It can measure the degree of damage of the composite intelligent structure and it also can tell us the damage position in the structure. This system consists of two parts ： software and hardware. Experiments of the damage detection and the analysis of the composite material structure with the photoelectric system were performed, and a series of damage detection experiments was conducted. The results prove that the performance of the system is well and the effects of the measure and test are evident. Through all the experiments, the damage detection technology and test system are approved to be real-time, effective and reliable in the damage detection of the composite intelligent structure.

Photoelectric detection technology of laser seeker signals

The measurement of the rolling angle of the projectile is one of the key technologies for the terminal correction projectile.To improve the resolution accuracy of the rolling angle in the laser seeker weapon system, the imaging model of the detector, calculation model of the position and the signal-to-noise ratio(SNR) model of the circuit are built to derive both the correlation between the resolution error of the rolling angle and the spot position, and the relation between the position resolution error and the SNR. Then the influence of each parameter on the SNR is analyzed at large,and the parameters of the circuit are determined. Meanwhile, the SNR and noise voltage of the circuit are calculated according to the SNR model and the decay model of the laser energy. Finally,the actual photoelectric detection circuit is built, whose SNR is measured to be up to 53 d B. It can fully meet the requirement of0.5° for the resolution error of the rolling angle, thereby realizing the analysis of critical technology for photoelectric detection of laser seeker signals.

Performance evaluation and optimization design of photoelectric pyrometer detection optical system

The measurement and control of high temperature play very important roles in national defense,military,scientific experiments,industrial and agricultural production.Photoelectric pyrometer is one of the important radiation thermometers for non-contact temperature measurement.It has an important application in the field of high temperature measurement,and its performance directly affects the accuracy of temperature measurement.By improving the design of the detection optical system of the photoelectric pyrometer,the imaging performance of the photoelectric pyrometer can be improved effectively,and the temperature measurement accuracy can be improved.In this paper,the temperature measurement principle of photoelectric pyrometer,the wo rking principle of the detection optical system and the composition of the system are introduced.The optical components that affect the imaging of the optical system of the photoelectric pyrometer are analyzed.The optical pyrometer detection optical system is simulated by ZEMAX software,based on the analysis results,the Modulation Transfer Function(MTF)and the spot Diagram are used as the main evaluation criteria to optimize the design of the objective lens of the photoelectric pyrometer detection optical system.The imaging performance of the photoelectric pyrometer detection optical system and the accuracy of temperature measurement of the photoelectric pyrometer are improved by optimization design of the detection optical system.

Multi-area detection sensitivity calculation model and detection blind areas influence analysis of photoelectric detection target

Multi-element array photoelectric detector is the core devices to form a photoelectric detection target with a large field of view.This photoelectric detection target brings about the problem of uneven detection sensitivity distribution in the detection screen.To improve the uneven detection sensitivity of this photoelectric detection target,this paper analyzes the distribution law of the uneven detection sensitivity of the photoelectric detection target using the multi-element array photoelectric detector,dissects the main factors affecting the detection sensitivity according to the photoelectric detection principle,establishes the calculation model of detection sensitivity of the photoelectric detection target in the different detection areas and proposes a method to improve the detection sensitivity by compensating the gain of each unit photoelectric detector.The analysis of simulation and experimental results show that the proposed method of photoelectric detection target can effectively improve the output signal amplitude of the projectile under the certain detection distance,in particular,the output signal amplitude of the projectile is significantly increased when the projectile passes through the detection blind area.The experimental results are consistent with the simulation results,which verify the effectiveness of the proposed improvement method.

Three-dimensional coordinates test method with uncertain projectile proximity explosion position based on dynamic seven photoelectric detection screen

To objectively obtain the three-dimensional coordinates of the projectile fuze proximity explosion when projectile intersects the head of missile target, we propose a dynamic seven photoelectric detection screen test method, which is made up of six plane detection screens and a flash photoelectric dynamic detection screen. The three-dimensional coordinates calculation model of the projectile proximity explosion position based on seven plane detection screens with dynamic characteristics is established.According to the relation of the dynamic seven photoelectric detection screen planes and the time values,the analytical function of the projectile proximity explosion position parameters under non-linear motion is derived. The projectile signal filtering method based on discrete wavelet transform is explored in this work. Additionally, the projectile signal recognition algorithm using an improved particle swarm is proposed. Based on the characteristics of the time duration and the signal peak error for the projectile passing through the detection screen, the signals attribution of the same projectile passing through six detection screens are analyzed for obtaining precise time values of the same projectile passing through the detection screens. On the basis of the projectile fuze proximity explosion test, the linear motion model and the proposed non-linear motion model are used to calculate and compare the same group of projectiles proximity explosion position parameters. The comparison of test results verifies that the proposed test method and calculation model in this work accurately obtain the actual projectile proximity explosion position parameters.

Bubble counter based on photoelectric technique for leakage detection of cryogenic valves

In order to overcome the inconvenience of manual bubble counting, a bubble counter based on photoelectric technique aiming for automatically detecting and measuring minute gas leakage of cryogenic valves is proposed. Experiments have been conducted on a self-built apparatus, testing the performance with different gas inlet strategies (bottom gas-inlet strategy and side gas-inlet strategy) and the influence of gas pipe length (0, 1, 2, 4, 6, 8, 10 m) and leakage rate (around 10, 20, 30, 40 bubbles/min) on first bubble time and bubble rate. A buffer of 110 cm3 is inserted between leakage source and gas pipe to simulate the down- stream cavum adjacent to the valve clack. Based on analyzing the experimental data, experiential parameters have also been summarized to guide leakage detection and measurement for engineering applications. A practical system has already been suc- cessfully applied in a cryogenic testing apparatus for cryogenic valves.

Application of Vacuum Photoelectric Detection Technology in Super-Resolution System

Due to the wave characteristics of light, diffraction occurs when the light passes through the optical system, so that the resolution of the ordinary far-field optical system is limited by the size of the Airy disk diameter. There are various factors that cause image quality degradation during system detection and imaging, such as optical system aberrations, atmospheric inter-ference, defocusing, system noise and so on. Super-resolution optical imaging technology is the most innovative breakthrough in the optical imaging and detection field in this century. It goes beyond the resolution limit of ordinary optical systems or detectors, and can get more details and information of the structure, providing unprecedented tools for various fields. Compared with ordinary optical systems, super-resolution systems have very high requirements on the signals to be detected, which cannot be met by ordinary detection techniques. Vacuum photoelectric detection and imaging technology is equipped with the characteristics of high sensitivity and fast response. It is widely used in super-resolution systems and has played a great role in super-resolution systems. In this paper, the principles and structure of the image-converter streak camera super-resolution system, scanning electron microscopy super-resolution system and laser scanning confocal super-resolution system will be sorted out separately, and the essential role of the vacuum photoelectric detection technology in the ultra-microscopic sys-tem will be analyzed.

Improvement Detecting Method of Optical Axes Parallelism of Shipboard Photoelectrical Theodolite Based on Image Processing

An improvement detecting method was proposed according to the disadvantages of testing method of optical axes parallelism of shipboard photoelectrical theodolite (short for theodolite) based on image processing. Pointolite replaced 0.2'' collimator to reduce the errors of crosshair images processing and improve the quality of image. What’s more, the high quality images could help to optimize the image processing method and the testing accuracy. The errors between the trial results interpreted by software and the results tested in dock were less than 10'', which indicated the improve method had some actual application values.

A line laser detection screen design and projectile echo power calculation in detection screen area

A line laser with high power as the background light source for the design of a new photoelectric detection target is proposed in this paper, aiming to improve the detection ability of the traditional photoelectric detection target under low background illumination. The laser emitted pulse waveform function and the laser echo pulse response function were used to establish the mathematical model of the reflected echo power of projectile in the detection area and derive the calculation function of minimum detectable echo power in the line laser detection screen, according to information of the line laser emitted power, incident angle of projectile, duration time and detection distance of projectile passing through the line laser detection screen. Calculations and experimental results showed that the design method of line laser detection screen and calculation model of laser echo power are reasonable, and the detection ability of line laser detection screen is obviously higher than that of traditional photoelectric detection screen, especially in low background illumination;at the same time, the designed line laser detection screen was used to combine a six line laser detection screen intersection test system, based on live ammunition for shooting. The test system is stable and able to obtain the dynamic parameters of the flying projectile, verifying that the design of the line laser detection screen in new photoelectric detection target can be suitable for shooting range test applications.

细长竹木圆棒双激光对射自动检测系统设计

针对细长竹木圆棒胚体存在的表面凹坑、开裂等外观缺陷,设计了一种双激光对射式自动检测系统。机械结构采用载物链条使细长竹木圆棒整体平移并在弹性压板下滚动,由对称布置的双激光斜入射至压板和圆棒贴合部位,实现对竹木圆棒表面的双螺旋扫描和空隙检测;控制部分以西门子S7-200 Smart PLC为主体,设计了与实体链条同步的数字链条进行并行控制。测试结果表明,系统相对于人工检测漏检率为0,具有成本低、效率高、可靠性高、易于使用等特点,可有效解决细长竹木圆棒胚体表面质量初筛问题。

微分散液滴的光纤检测研究

微分散是微化工技术的重要组成部分,传统利用显微摄像分析和统计微分散液滴的方法成本高,不易推广。提出了一种基于光纤传感的微分散液滴在线检测技术,该方法基于漫反射光纤、光纤传感器、数据采集卡和LabVIEW程序实现了微通道内液滴生成频率和长度的在线检测,满足0.21 mm以上直径液滴的检测,检测频率上限为500 Hz,当液滴通过光纤时间超过15 ms时,还可检测液滴长度。研究结果表明光纤直径和光纤传感器响应时间是影响该方法检测性能的主要因素,与相似平台对比,以较低的成本实现了较高检测性能。

TDLAS气体激光遥测高灵敏光电探测电路设计

针对气体激光遥测光信号微弱、环境因素干扰强等特点,结合波长调制技术,设计和研究了用于TDLAS激光遥测的高灵敏度光电探测电路(Highly Sensitive Photoelectric Detection Circuit,HSPDC)。基于波长调制技术,确定了TDLAS信号噪声抑制方法;采用光电二极管理想模型,分析了光电探测电路的线性响应特性并确定了光电二极管的关键参数;基于级联放大原理设计、仿真并对HSPDC进行测试。结果表明:所设计HSPDC的光功率检测下限为0.11 nW,信号衰减仅为0.79 dB(f=10 kHz),截止频率较现有108 V/A跨阻放大电路高一个数量级,可用于高速调制微弱光信号的探测。搭建了气体激光遥测系统,当调制频率为3 kHz时,激光遥测系统获得了良好的检测性能,检测灵敏度达到88.66 mV/ppm,检测限优于0.565 ppm,线性拟合度R2为0.9996。研究表明,研制的HSPDC光电探测电路具有响应速度快、检测灵敏度高等优点,可集成化,能满足气体激光遥测应用需求。

基于卡尔曼算法的激光告警自适应控制系统

针对二维激光告警系统在极端环境下成像质量差的问题,设计了一种基于卡尔曼算法的自适应控制系统。采用两个InGaAs焦平面阵列探测器分别对来袭激光的角度进行精测和粗测,对卡尔曼算法进行推导优化和仿真验证,同时,基于改进后的卡尔曼算法,通过FPGA实现两个探测器的自适应积分控制,达到系统输出自适应控制的目的。结果显示,精测的卡尔曼预测平均误差为0.56%,粗测的卡尔曼预测平均误差为0.78%,在532 nm的模拟光源照射下,自适应控制系统在极端光强下减少了欠曝和过曝的干扰,在不同光强下光斑大小稳定在55个像素左右。实验表明,自适应控制系统提高了激光告警系统在不同光强下的成像稳定性,对激光告警系统在恶劣环境下工作具有重要意义。

黑磷半导体光物理及应用研究进展

与其他二维材料相比,二维黑磷具有较高的载流子迁移率、宽可调带隙和面内各向异性等特点,在晶体管、光子学、光电子学、传感器、电池和催化等领域引起科学家的广泛关注.然而,黑磷在自然环境条件下的不稳定性以及大面积、高质量半导体黑磷纳米材料制备的局限性严重滞缓了其在纳米器件、催化以及生物光子学领域的快速发展.本工作总结了近年来高稳定性黑磷纳米材料的可控制备和光学性质,重点突出其在光电探测器、非线性和线性光学、光催化和生物光子学等光学应用方面的研究进展,并对黑磷在未来光电子器件、光催化以及生物光子的挑战及机遇做出相应展望.

桁架式自动插装机器人控制系统设计

为了解决人工插装电子元件存在的效率及合格率低等问题,面向中小型3C企业的低成本桁架式线路板插装机器的控制系统开发,以电容插装为例,完成系统的上料、拾取、检测和插件等控制过程的设计,利用数据库完成插装关键信息的存储。系统采用通讯方式完成桁架式机器人的运动控制,具有控制灵活、成本低的优点;利用光电检测技术完成电容引脚距离检测、利用扭矩检测完成电容插入状态的判断,具有时间短、效率高的优点。系统经过实验测试,各项指标均满足设计要求。

小型光电编码器误差自动检测系统

为了提高小型光电编码器误差检测的精度和效率,拓展编码器误差检测的应用,设计了一种误差检测系统。通过对编码器误差来源分析,以步进电机为动力,DSP芯片为数据采集与电机驱动核心,21位高精度编码器为角度基准,搭建了可进行编码器动态误差与静态误差自动检测的系统。并通过对误差的分析与拟合,实现了对编码器的误差补偿,提高了被检编码器测量精度。经实际检测验证,所设计编码器误差检测系统达到设计要求。

基于FPGA的双目高精度宽波段激光告警系统

针对传统二维激光告警系统的光斑中心提取误差大、角度测量精度差和分辨率低的问题,设计了一种基于FPGA和InGaAs焦平面阵列探测器的高精度宽波段激光告警系统,对传统的Otsu(最大类间方差法)阈值分割算法进行了推导和优化,同时,基于改进后的算法,通过FPGA实现了光斑中心坐标提取以及方位角、俯仰角等参数的计算,并将结果传输至上位机实时监测;实验结果显示,相较于传统的阈值分割算法,改进后的Otsu算法使光斑中心提取精度达到了0.06个像素,改进后的激光告警系统角度测量平均误差为0.03°,角度分辨率达到0.05°;实验表明,双目高精度宽波段激光告警系统达到了实际应用的要求,提高了系统测量的角度分辨率和精度,对光电探测和激光告警领域的工作具有一定的意义。

基于光电标签的火箭橇全程测速技术研究

火箭橇试验在兵器研制和性能测试上起着至关重要的作用,现有火箭橇测速方法均存在一些不足之处,针对火箭橇试验中全程速度测量难题,提出了一种基于光电标签的火箭橇全程速度测量方法;建立了光电标签的探测模型,对光电标签的原向反射特性进行研究,分析并仿真了传感器在动态测量中的信号变化过程,基于信号的频率特性对光电探测器件与信号处理电路进行选型,设计并搭建出硬件测量电路,对系统进行了测试与验证;实验结果表明:传感器对光电标签的探测距离可达40 cm,系统速度测量范围满足了火箭橇试验在兵器靶场上的应用,与传统方法相比,光电标签法成本更低、易实现,在火箭橇全程速度测量中有更广泛的应用场景。

基于网格的多目标模板匹配晶粒位置检测方法

针对传统方法中晶粒位置检测的耗时长、精度低等局限性,提出一种基于网格的多目标模板匹配晶粒位置检测方法。通过改进传统的模板匹配方法,结合非极大值抑制算法,将芯片晶粒的检测速度和精度提高。实验结果表明:该算法在单一同种晶粒的算法识别率能够达到97%以上,单张图像耗时<200 ms,能够克服明暗不同造成的检测困难,达到技术指标要求。

基于动态门限与自适应插值的外引导平滑算法

为了实现靶场光电经纬仪外引导数据的实时平滑,确保外引导数据驱动下光电经纬仪稳定获取图像,提出基于动态门限的野值处理算法和基于自适应插值的处理算法。对于外引导数据中的野值,提出一种利用影响函数动态计算样本方差的方式,构建动态判别门限实时完成野值的处理;对于外引导数据的插值处理,判断插值计算的连贯性,并将外引导的“卡顿”数据进行分类,采取不同的策略实时自适应插值。实验结果表明:基于动态门限的五点外推野值剔除方法,野值检测率平均在80%以上,同时虚警率较低;插值处理算法能同时应对卡顿与非卡顿的外引导数据,处理结果平滑连贯。算法已成功应用于海军某观测站的光电经纬仪,满足了靶场弹道测量系统的需要。