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利用电光偏转器进行激光脉冲整形的两种扫描光路的比较 被引量:1
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作者 谢兴龙 陈绍和 +1 位作者 许世忠 邓锡铭 《中国激光》 EI CAS CSCD 北大核心 1996年第12期1091-1096,共6页
从理论上系统地比较了利用电光偏转器进行激光脉冲进形的两种扫描光路.并对两种扫描方式的优缺点进行了论述,指出了一种对空间扫描线复原精度的估计方法.为现阶段神光-Ⅱ升级的实验工作提供了理论基础.
关键词 扫描光路 电光偏转器 激光脉冲整形
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大型工件扫描式激光喷丸系统研制
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作者 余雄超 胡永祥 姚振强 《航空制造技术》 2018年第7期84-88,共5页
对大型工件扫描式激光喷丸系统进行研制,主要目的是解决激光喷丸针对大型工件的应用问题以及实现工艺过程中激光光斑质量的良好控制。其主要包含作为激光光源的高能量纳秒激光器模块、对激光光斑的尺寸和形状进行调整控制的光斑调节模... 对大型工件扫描式激光喷丸系统进行研制,主要目的是解决激光喷丸针对大型工件的应用问题以及实现工艺过程中激光光斑质量的良好控制。其主要包含作为激光光源的高能量纳秒激光器模块、对激光光斑的尺寸和形状进行调整控制的光斑调节模块、导引激光进行大幅面扫描的两轴振镜模块以及装夹工件并对工件施加弹性预弯的柔性预应力夹具模块。在此基础上结合激光喷丸的工艺特点进行系统的控制流程规划。对制备的系统样机进行激光喷丸光斑质量控制的试验验证,结果表明,通过基于正交柱面透镜组的光斑调节模块的调整,所形成的光斑基本符合规划的目标参数要求,光斑的尺寸与形状质量可实现良好的控制。 展开更多
关键词 激光喷丸 扫描光路 柱面透镜 光斑形状 畸变校正
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基于双目视觉的激光喷丸大幅面动态扫描系统光束指向标定方法
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作者 毛展晨 胡永祥 《电加工与模具》 2021年第6期52-57,67,共7页
大型工件的激光喷丸成形由于工作范围广,一般采用动态扫描光路系统。二维振镜系统通过轴线互相垂直的振镜偏转实现激光的高速扫描,适用于大幅面的激光喷丸成形,然而振镜系统的扫描场存在固有的几何畸变,并且系统中的各种因素耦合的误差... 大型工件的激光喷丸成形由于工作范围广,一般采用动态扫描光路系统。二维振镜系统通过轴线互相垂直的振镜偏转实现激光的高速扫描,适用于大幅面的激光喷丸成形,然而振镜系统的扫描场存在固有的几何畸变,并且系统中的各种因素耦合的误差也会影响实际工作。基于双目视觉根据实际激光喷丸系统设计分步标定方案,利用指示光斑测量坐标建立双目-振镜坐标系的固有联系,同时标定喷丸工作距离,分析末端振镜扫描指向误差根源,划分校正网格对激光指向误差进行补偿。试验结果表明:标定方法可以有效克服激光指向误差,精度符合激光喷丸成形的工艺要求。 展开更多
关键词 二维振镜 双目视觉 扫描光路
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基于SPAD阵列的共光路扫描三维成像 被引量:2
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作者 康岩 薛瑞凯 +2 位作者 李力飞 张同意 高奇 《激光与光电子学进展》 CSCD 北大核心 2021年第10期289-298,共10页
基于单光子雪崩二极管(SPAD)阵列探测器的三维成像技术在工业和科学领域具有重要的应用前景。然而现有的SPAD阵列器件仍存在小阵列规模和低像素填充率所导致的低空间分辨率问题,为此基于SPAD阵列(32pixel×32pixel)和衍射光学元件(D... 基于单光子雪崩二极管(SPAD)阵列探测器的三维成像技术在工业和科学领域具有重要的应用前景。然而现有的SPAD阵列器件仍存在小阵列规模和低像素填充率所导致的低空间分辨率问题,为此基于SPAD阵列(32pixel×32pixel)和衍射光学元件(DOE)搭建收发共光路扫描三维成像实验系统。利用DOE将出射激光整形为激光点阵并与接收视场匹配可以提升激光能量利用效率,通过共光路扫描可以实现高分辨三维成像。利用基于滑动时间窗的噪声光子滤除算法和基于全变分正则化的图像重构算法对回波光子数据进行处理。实验结果表明,图像重构算法可以获取10 m外目标64 pixel×64 pixel的三维图像,且在平均每像素0.86个信号光子的条件下实现清晰成像,成像结果的平均绝对误差为0.016m。 展开更多
关键词 成像系统 三维成像 光子计数 飞行时间 光路扫描 正则化方法
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Automated extraction of expressway road surface from mobile laser scanning data 被引量:3
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作者 TRAN Thanh Ha TAWEEP Chaisomphob 《Journal of Central South University》 SCIE EI CAS CSCD 2020年第7期1917-1938,共22页
This paper presents a voxel-based region growing method for automatic road surface extraction from mobile laser scanning point clouds in an expressway environment.The proposed method has three major steps:constructing... This paper presents a voxel-based region growing method for automatic road surface extraction from mobile laser scanning point clouds in an expressway environment.The proposed method has three major steps:constructing a voxel model;extracting the road surface points by employing the voxel-based segmentation algorithm;refining the road boundary using the curb-based segmentation algorithm.To evaluate the accuracy of the proposed method,the two-point cloud datasets of two typical test sites in an expressway environment consisting of flat and bumpy surfaces with a high slope were used.The proposed algorithm extracted the road surface successfully with high accuracy.There was an average recall of 99.5%,the precision was 96.3%,and the F1 score was 97.9%.From the extracted road surface,a framework for the estimation of road roughness was proposed.Good agreement was achieved when comparing the results of the road roughness map with the visual image,indicating the feasibility and effectiveness of the proposed framework. 展开更多
关键词 mobile laser scanning SEGMENTATION road surface EXPRESSWAY VOXELIZATION point cloud
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Automatic Road Extraction in Rural Areas Based on Digital Imaging and Laser Scanner Data
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作者 Claudionor Ribeiro da Silva Jorge Ant6nio Silva Centeno Maria Joao Henriques 《Journal of Civil Engineering and Architecture》 2011年第4期285-296,共12页
Digitizing road maps manually is an expensive and time-consuming task. Several methods that intend to develop fully or semi-automated systems have been proposed. In this work we introduce a method, based on the Radon ... Digitizing road maps manually is an expensive and time-consuming task. Several methods that intend to develop fully or semi-automated systems have been proposed. In this work we introduce a method, based on the Radon transform and optimal algorithms, which extracts automatically roads on images of rural areas, images that were acquired by digital cameras and airborne laser scanners. The proposed method detects linear segments iteratively and starting from this it generates the centerlines of the roads. The method is based on an objective function which depends on three parameters related to the correlation between the cross-sections, spectral similarity and directions of the segments. Different tests were performed using aerial photos, Ikonos images and laser scanner data of an area located in the state of Parana (Brazil) and their results are presented and discussed. The quality of the detection of the roads centerlines was computed using several indexes - completeness, correctness and RMS. The values obtained reveal the good performance of the proposed methodology. 展开更多
关键词 Radon transform automatic extraction ROADS laser scanning digital image
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