输电线路异物入侵多维度检测及预警系统

输电线路是电网的重要组成部分,其分布范围广、工况复杂,极易遭受到外力破坏。为预防异物入侵影响输电线路的安全稳定运行,设计了一套输电线路异物入侵多维度检测及预警系统,可实现对电力现场入侵物体空间位置确定、与架空线之间的距离测算。该系统可提高输电线路的整体智能化运维水平,提升工作效率,降低运维成本,有效保证电网运行安全。     

一种异物清除作业机器人机构的优化设计

针对输电线路的作业环境和异物清除的作业特点,提出一种适用于输电线路异物清除作业的机器人机构优化设计。该机器人机构包括机器人移动本体和作业工具,作业工具包括电热清除工具及电锯清除工具,可实现对输电线路上的可燃性和可切割性异物的清除作业。建立机器人的运动学模型,仿真分析电锯清除作业和电热清除作业的过程,对机器人样机系统进行优化设计。相关实验结果验证了该机器人系统具备在输电线路上清除可燃性或可切割性异物的功能。     

双轨安装现场激光准直测量系统的设计

激光准直测量系统由半导体激光器、光学分光及转向系统、光电接收系统及液晶显示模块组成.激光光束经转向系统后出射两条相互平行的基准光束,作为导轨的安装检测基准.该系统利用二维PSD作为光电接收器件,采用液晶显示模块显示导轨偏差,可快速、直接、准确地测量导轨安装的偏移量,从而提高导轨安装的精度和速度.实验结果显示测量系统在X,Y方向上的标准偏差分别为:0.002 mm,0.005 mm.     

激光清障技术在电网中的应用现状与发展

电能是现代社会最重要的动力源,而附着于输电线路上的各类障碍,如异物、覆冰、树障等对输电线路与电网的安全稳定运行造成了巨大威胁。传统的清障方法存在各自的缺点,有的存在安全隐患,有的耗能较高,且大多需要停电处理。激光有着能量高,准直性好等优点,可用于远距离无接触地击落异物或融化覆冰,因此激光清障技术近年来受到越来越多的关注。本文总结了国内激光清障技术在电网中的应用与研究成果,阐述了目前使用激光清除覆冰、异物、树障等不同类型障碍的原理以及优缺点;介绍了常用于清障的几种激光器的特点;分析了激光波长、激光功率、光斑直径等常见参数对于清障效率的影响;总结了激光辐照可能对导线以及绝缘子等电力设备的影响。分析了光功率密度与辐照时间的安全阈值问题;展望了未来激光清障技术的几种可能的发展方向。     

输电线路激光除冰技术试验分析及工程应用设计

为防止覆冰对输电线路的危害,从理论分析、模拟试验、工程应用设计等方面系统研究了输电线路激光除冰技术,分别得出了CO2、Nd:YAG激光除冰特性:1.5kW CO2激光融冰体速度约为728.5mm3/s,单位能耗为2.08J/mm3;Nd:YAG固体激光融冰效果稍高于CO2激光,突出优点在于其热应力除冰;激光除冰时瓷绝缘子安全阈值约20.5～54.4J/mm2,复合绝缘子远小于该值,导线安全阈值很高,几乎不会损伤。结果表明激光可用于输电线路除冰,具有热融冰效应和热应力效应,如结合机械除冰可大大提高除冰效率和效果。根据研究结果提出了其工程应用设计方案:工程化车载式激光除冰系统选用固体激光器,输出功率1～1.5kW,光斑直径15～20mm,发散角3mrad,作用距离为100～1000m,激光电源采用车载发电机,总功耗≤50kW。预计未来3～5a激光除冰速度将可提高3～4倍,激光除冰系统可向小型化、便携式方法发展。     

大功率激光强度分布测量系统

文中针对激光加工大功率激光光束光斑功率密度分布测量的要求,设计了测量系统,实现了对大功率光束光斑的检测。     

高精度钢轨端面坡度测量算法研究

当前国内在焊接钢轨之前需要通过塞尺与角度尺等接触式工具测量钢轨垂直度与端面坡度,由于人工测量步骤复杂, 测量效率低,故研究了一种基于激光轮廓仪非接触式钢轨测量系统。 系统由 4 个激光轮廓仪采集钢轨整个端面及侧面信息,然 后运用二面角原理完成钢轨端面与侧面、端面与底面夹角的计算,最后再通过直角尺模型测得端面坡度。 经现场测试,钢轨垂 直度的重复测量误差小于 0. 2°,测量精度最高可达 0. 3°,端面坡度极限误差达到 0. 04 mm。 实验结果证明所设计系统能够高效 而又稳定地完成钢轨垂直度的检测工作,满足实际测试要求。     

基于机器视觉的牵引供电接触网异物清除系统

列车在运行过程中,使用受电弓从铁路沿线接触网取得电力,而接触网大多都露天架设,极容易被各种异物悬挂,导致列车延误或发生安全事故。目前对接触网大多采用人工现场巡检方式,工作量大且效率低下。针对以上问题,设计了一种基于机器视觉的接触网异物清除系统,该系统由异物清除机器人和异物清除管理软件构成。异物清除机器人悬挂在接触线上,可自动运动拍摄视频,并利用机器视觉技术自动识别接触网上是否悬挂异物,若发现异物及时使用自带的大功率激光器清除,同时将相关数据通过4G网络发送到调度控制中心;异物清除管理软件收集并分析各个机器人上传的数据,若发现异物及时通知相关工作人员处理以保障列车运行安全,同时也能有效降低人工巡检工作量,提升巡检效率。     

车轮热轧轮胚尺寸激光测量系统的研究

采用激光测量和视觉测量相结合的方法设计了车轮热轧轮胚尺寸激光测量系统的硬件结构和测量方案,设计了系统的靶标标定方法,并针对高温状态的曲面尺寸进行了测量实验。通过分析实验结果,得到测量系统对于常温状态下车轮轮辋相关尺寸单次测量的标准差分别为0.3865mm、0.1862mm和0.1561mm,20~1000℃热态测量时,测量结果的标准差为0.0390mm。     

AD7656在四频差动激光陀螺信号检测系统中的应用

为实现四频差动激光陀螺的稳频控制等功能,需要快速精确测量陀螺的光强、电流和温度信号。使用单片6通道、16位AD转换芯片AD7656,与高性能DSP芯片TMS320F2812设计而成的检测系统,解决了XINTF接口数据传输等问题,并采用均值滤波方法,能有效、实时、精确地采样四频差动激光陀螺各种信号,大大降低陀螺测量控制电路的功率和体积。在10kHz的采样率下,系统测量信号精度可达10^-4量级。电路能够长期稳定工作,满足对陀螺信号的测量要求,达到预期目标。     

Fiberoptic Confocal Microscopy Using a 1.55-μm Fiber Laser for Multimodal Biophotonics Applications

We have experimentally demonstrated a fiberoptic confocal microscope using a 1.55-mum laser source. A compact and efficient Er-doped fiber laser source and conventional single-mode fiber components were used to construct a near-infrared fiberoptic confocal microscope system with 3-D scanning capability. A broadband 1.55-mum light source was used to reduce fringe patterns and interferences that occur when a highly coherent source is used. Our system showed a lateral resolution as high as 1.1 mum with a 60times objective lens, which is close to the theoretical limit. The system can be used in various multimodal biophotonics platforms including precise 3D imaging, biosensing, and laser tissue ablation due to its high water absorption characteristics while maintaining low thermomechanical and self-focusing damage from high-power lasers.     

Airy光束聚焦后自恢复与透镜校正研究

Airy光束是一种特殊的无衍射光束,具有自恢复性及自弯曲性。根据衍射理论对聚焦后有限能量Airy光束的自恢复现象进行了研究,利用三角棱镜和圆形聚焦透镜组成的光学系统产生了Airy光束,所得到的Airy光束衰减较快。通过增加透镜对光束进行修正,并对修正前后Airy光束的光强分布的变化进行数值模拟和对比。结果表明,在一定传输距离内,有限能量Airy光束聚焦后自恢复光束随着传播距离的增大很快衰减。通过加入校正透镜可以抑制Airy光束的衰减。     

相位式激光测宽仪的设计和实现

自60年代初期激光的出现,激光测距取代了传统的测距方法成为测距系统的主流.本文所设计的激光测宽仪实际上是在激光测距的基础上实现双向测量,是激光测距的一个应用,旨在设计一套体形轻巧、性价比高、测距精度较高的双向测距系统,所采用的是相位法,即对半导体激光器直接调制使激光连续发射,通过测量往返信号之间的相位差实现距离的测量.文中采用了直接数字频率合成技术(DDS),保证了主振和本振频率的准确性也避免了传统测距系统中正弦发生信号所出现的频率漂移和相位抖动等问题,实验结果比较理想.     

Development and field test of a laser-based nonintrusive detection system for identification of vehicles on the highway

A real-time laser-based nonintrusive detection system has been developed for the measurement of true travel time of vehicles on the highway. The detection system uses a laser line that is projected onto the ground as a probe. The reflected light is collected and focused into a photodiode array by an optical system. Vehicle presence is detected based on the absence of reflected laser light. By placing two identical laser/sensor pairs at a known distance apart, the speeds of both the front and rear of a vehicle are measured based on the times when each sensor is triggered. The length of each vehicle is determined by using these speed measurements and the residence time of the vehicle under each sensor. Using real-time software, the speed, acceleration, and length of a detected vehicle can be calculated and displayed simultaneously. A new prototype system has been tested on the highway with different types of vehicles and scenarios, and the results are presented here. The tests have also been carried out for different weather conditions and road materials. The results indicate that the laser system operates well under real highway conditions.     

Feasibility of Neural Stimulation With Floating-Light-Activated Microelectrical Stimulators

Neural microstimulation is becoming a powerful tool for the restoration of impaired functions in the central nervous system. Microelectrode arrays with fine wire interconnects have traditionally been used in the development of these neural prosthetic devices. However, these interconnects are usually the most vulnerable part of the neuroprosthetic implant that can eventually cause the device to fail. In this paper, we investigate the feasibility of floating-light-activated microelectrical stimulators (FLAMES) for wireless neural stimulation. A computer model was developed to simulate the micro stimulators for typical requirements of neural activation in the human white and gray matters. First, the photon densities due to a circular laser beam were simulated in the neural tissue at near-infrared (NIR) wavelengths. Temperature elevation in the tissue was calculated and the laser power was retrospectively adjusted to 325 and 250 mW/cm(2) in the gray and white matters, respectively, to limit ΔT to 0.5 °C. Total device area of the FLAMES increased with all parameters considered but decreased with the output voltage. We conclude that the number of series photodiodes in the device can be used as a free parameter to minimize the device size. The results suggest that floating, optically activated stimulators are feasible at submillimeter sizes for the activation of the brain cortex or the spinal cord.     

The Optics of Reflectors for Illumination

Although lens optics are a highly sophisticated and extremely advanced technology, nonimaging reflector optics for illumination only have been strangely neglected until very recently. The author's book The Optical Design of Reflectors that first appeared in 1974 is the only extant book covering this important subject comprehensively. In the past most reflector forms other than elementary parabolic or elliptical shapes have been produced by crude heuristic and empirical shop procedures, even by some of the most technically advanced American manufacturers. The mathematics of relatively simple reflector geometries of the types most commonly needed are presented. Simple examples illustrate the derivation of curves for circular reflectors designed to any beam specification, even for completely arbitrary beam shapes. Alternative ray-tracing and graphical integration methods are given. References provide sources from which complicated and highly sophisticated asymmetric reflector designs can be accomplished. Compensation for large or elongated light sources by means of the phantom light center is covered. Some visual background material is included to guide designers in matters of glare avoidance as well as other relevant physiology of the human eye.     

基于复合抛物面反光杯和菲涅尔透镜组合的洗墙灯LED条形光斑设计优化

根据非成像光学设计原理和方法,提出一种基于复合抛物面反光杯和菲涅尔透镜组合的LED条形光斑光学器件设计。采用Tracepro软件对反光杯的反射面进行二次抛物曲线拟合和菲涅尔透镜折射棱齿斜率进行计算,并对此条形光斑光学系统模拟与分析,制作实际模型测试,达到洗墙灯具所需光束角(50%Imax)[C0/180]面为10°和[C90/270]面为60°的条形光斑,且20 W洗墙灯具在5 m远处平均照度可达140 lx,可以解决传统全内反射TIR条纹透镜副光斑大、光线利用低、洗墙距离短、灯具眩光等问题。     

Lens With Transformable-Type and Tunable-Focal-Length Characteristics

A versatile lens with transformable-type and tunable-focal-length characteristics has been presented. The conventional punching technology is adopted to fabricate the lens structure due to its inherently high direction-holding capability. As a result, the alignment between two ends of the lens can be easily achieved without requiring complicated process. At the same time, soft lithography is used to realize structure similar to liquid-filled lens except the working medium being air rather than liquid acting as a tuning mechanism. These two parts are eventually combined together with bonding under oxygen plasma activation. With this design, large flexibility in performance tuning will be added to the lens, which has been experimentally demonstrated in beam shaping and imaging applications.     

光学薄膜制备用的多离子束电子束系统

本文介绍一种新型的光学薄膜制备用多离子束电子束系统。