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Aggregate Point Cloud Geometric Features for Processing
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作者 Yinghao Li Renbo Xia +4 位作者 Jibin Zhao Yueling Chen Liming Tao Hangbo Zou Tao Zhang 《Computer Modeling in Engineering & Sciences》 SCIE EI 2023年第7期555-571,共17页
As 3D acquisition technology develops and 3D sensors become increasingly affordable,large quantities of 3D point cloud data are emerging.How to effectively learn and extract the geometric features from these point clo... As 3D acquisition technology develops and 3D sensors become increasingly affordable,large quantities of 3D point cloud data are emerging.How to effectively learn and extract the geometric features from these point clouds has become an urgent problem to be solved.The point cloud geometric information is hidden in disordered,unstructured points,making point cloud analysis a very challenging problem.To address this problem,we propose a novel network framework,called Tree Graph Network(TGNet),which can sample,group,and aggregate local geometric features.Specifically,we construct a Tree Graph by explicit rules,which consists of curves extending in all directions in point cloud feature space,and then aggregate the features of the graph through a cross-attention mechanism.In this way,we incorporate more point cloud geometric structure information into the representation of local geometric features,which makes our network perform better.Our model performs well on several basic point clouds processing tasks such as classification,segmentation,and normal estimation,demonstrating the effectiveness and superiority of our network.Furthermore,we provide ablation experiments and visualizations to better understand our network. 展开更多
关键词 Deep learning point-based models point cloud analysis 3D shape analysis point cloud processing
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Point Cloud Processing Methods for 3D Point Cloud Detection Tasks
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作者 WANG Chongchong LI Yao +2 位作者 WANG Beibei CAO Hong ZHANG Yanyong 《ZTE Communications》 2023年第4期38-46,共9页
Light detection and ranging(LiDAR)sensors play a vital role in acquiring 3D point cloud data and extracting valuable information about objects for tasks such as autonomous driving,robotics,and virtual reality(VR).Howe... Light detection and ranging(LiDAR)sensors play a vital role in acquiring 3D point cloud data and extracting valuable information about objects for tasks such as autonomous driving,robotics,and virtual reality(VR).However,the sparse and disordered nature of the 3D point cloud poses significant challenges to feature extraction.Overcoming limitations is critical for 3D point cloud processing.3D point cloud object detection is a very challenging and crucial task,in which point cloud processing and feature extraction methods play a crucial role and have a significant impact on subsequent object detection performance.In this overview of outstanding work in object detection from the 3D point cloud,we specifically focus on summarizing methods employed in 3D point cloud processing.We introduce the way point clouds are processed in classical 3D object detection algorithms,and their improvements to solve the problems existing in point cloud processing.Different voxelization methods and point cloud sampling strategies will influence the extracted features,thereby impacting the final detection performance. 展开更多
关键词 point cloud processing 3D object detection point cloud voxelization bird's eye view deep learning
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Comparison of Results of Different GPS Post-processing Software
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作者 Dapeng SHI 《Asian Agricultural Research》 2024年第6期33-35,共3页
In order to obtain high-precision GPS control point results and provide high-precision known points for various projects,this study uses a variety of mature GPS post-processing software to process the observation data... In order to obtain high-precision GPS control point results and provide high-precision known points for various projects,this study uses a variety of mature GPS post-processing software to process the observation data of the GPS control network of Guanyinge Reservoir,and compares the results obtained by several kinds of software.According to the test results,the reasons for the accuracy differences between different software are analyzed,and the optimal results are obtained in the analysis and comparison.The purpose of this paper is to provide useful reference for GPS software users to process data. 展开更多
关键词 GPS Data processing point POSITION PRECISION
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Building Facade Point Clouds Segmentation Based on Optimal Dual-Scale Feature Descriptors
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作者 Zijian Zhang Jicang Wu 《Journal of Computer and Communications》 2024年第6期226-245,共20页
To address the current issues of inaccurate segmentation and the limited applicability of segmentation methods for building facades in point clouds, we propose a facade segmentation algorithm based on optimal dual-sca... To address the current issues of inaccurate segmentation and the limited applicability of segmentation methods for building facades in point clouds, we propose a facade segmentation algorithm based on optimal dual-scale feature descriptors. First, we select the optimal dual-scale descriptors from a range of feature descriptors. Next, we segment the facade according to the threshold value of the chosen optimal dual-scale descriptors. Finally, we use RANSAC (Random Sample Consensus) to fit the segmented surface and optimize the fitting result. Experimental results show that, compared to commonly used facade segmentation algorithms, the proposed method yields more accurate segmentation results, providing a robust data foundation for subsequent 3D model reconstruction of buildings. 展开更多
关键词 3D Laser Scanning point Clouds Building Facade Segmentation point Cloud processing Feature Descriptors
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Joint asymptotic distribution of exceedances point process and partial sum of stationary Gaussian sequence 被引量:3
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作者 TAN Zhong-quan PENG Zuo-xiang 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2011年第3期319-326,共8页
Let {Xi}i=1^∞ be a standardized stationary Gaussian sequence with covariance function τ(n) =EX1Xn+1, Sn =∑i=1^nXi,and X^-n=Sn/n.And let Nn be the point process formed by the exceedances of random level (x/√2 l... Let {Xi}i=1^∞ be a standardized stationary Gaussian sequence with covariance function τ(n) =EX1Xn+1, Sn =∑i=1^nXi,and X^-n=Sn/n.And let Nn be the point process formed by the exceedances of random level (x/√2 log n+√2 log n-log(4π log n)/2√log n) √1-τ(n) + X^-n by X1,X2,…, Xn. Under some mild conditions, Nn and Sn are asymptotically independent, and Nn converges weakly to a Poisson process on (0,1]. 展开更多
关键词 stationary Gaussian sequence exceedances point process partial sum.
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Energy Efficiency Optimization for Heterogeneous Cellular Networks Modeled by Matérn Hard-Core Point Process 被引量:4
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作者 Yonghong Chen Jie Yang +1 位作者 Xuehong Cao Shibing Zhang 《China Communications》 SCIE CSCD 2020年第8期70-80,共11页
The Poisson point process(PPP) has been widely used in wireless network modeling and performance analysis due to the independence between its nodes. Therefore, it may not be a suitable model for many of the exclusive ... The Poisson point process(PPP) has been widely used in wireless network modeling and performance analysis due to the independence between its nodes. Therefore, it may not be a suitable model for many of the exclusive networks between the nodes. This paper analyzes the energy efficiency(EE) and optimizes the two-tier heterogeneous cellular networks(Het Nets). Considering the mutual exclusion between macro base stations(MBSs) distribution, the deployment of MBSs is modeled by the Matérn hard-core point process(MHCPP), and the deployment of pico base stations(PBSs) is modeled by the PPP. We adopt a simple approximation method to study the signal to interference ratio(SIR) distribution in two-tier MHCPP-PPP networks and then derive the coverage probabilities, the average data rates and the energy efficiency of Het Nets. Finally, an optimization algorithm is proposed to improve the EE of Het Nets by controlling the transmit power of PBSs. The simulation results show that the EE of a system can be effectively improved by selecting the appropriate transmit power for the PBSs. In addition, two-tier MHCPP-PPP Het Nets have higher energy efficiency than two-tier PPP-PPP Het Nets. 展开更多
关键词 energy efficiency heterogeneous cellular networks coverage probability matérn hard-core point process
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Reliability Analysis of Repairable Systems Using Stochastic Point Processes 被引量:1
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作者 谭芙蓉 江志斌 白同朔 《Journal of Shanghai Jiaotong university(Science)》 EI 2008年第3期366-369,共4页
In order to analyze the failure data from repairable systems, the homogeneous Poisson process (HPP) is usually used. In general, HPP cannot be applied to analyze the entire life cycle of a complex, re-pairable system ... In order to analyze the failure data from repairable systems, the homogeneous Poisson process (HPP) is usually used. In general, HPP cannot be applied to analyze the entire life cycle of a complex, re-pairable system because the rate of occurrence of failures (ROCOF) of the system changes over time rather than remains stable. However, from a practical point of view, it is always preferred to apply the simplest method to address problems and to obtain useful practical results. Therefore, we attempted to use the HPP model to analyze the failure data from real repairable systems. A graphic method and the Laplace test were also used in the analysis. Results of numerical applications show that the HPP model may be a useful tool for the entire life cycle of repairable systems. 展开更多
关键词 repairable systems reliability analysis homogeneous Poisson process (HPP) rate of occurrence of failures (ROCOF) stochastic point process Laplace test
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The SCUSUM Estimation of Variance Change Point in Linear Process 被引量:1
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作者 ZHAO Wen-zhi XIA Zhi-ming 《Chinese Quarterly Journal of Mathematics》 CSCD 2011年第2期170-173,共4页
This paper considers the estimation problem of a variance change-point in linear process.Consistency of a SCUSUM type change-point estimator is proved and its rate of convergence is established.The mean-unknown case i... This paper considers the estimation problem of a variance change-point in linear process.Consistency of a SCUSUM type change-point estimator is proved and its rate of convergence is established.The mean-unknown case is also considered. 展开更多
关键词 variance change point linear process rate of convergence
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Model for Failure Point Process of a Repairable System and Application 被引量:1
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作者 JIANG Renyan CHEN Hao 《International Journal of Plant Engineering and Management》 2018年第2期89-96,共8页
A engineering system is usually repairable, and failure process of a repairable by a failure point process. The power law model is a commonly used approach to model syst the em is often described failure point process... A engineering system is usually repairable, and failure process of a repairable by a failure point process. The power law model is a commonly used approach to model syst the em is often described failure point process. This paper introduces the concept and model for the failure process of repairable system. The method of parameter estimation is developed, and failure observations are fitted into a power-law model by using the least square method. Two applications of the pressent model are discussed according to the practical failure data of the central cooling system of a nuclear power plant. One application is determining the optimal overhaul time, and the other is evaluating the quality of maintenance. This paper provides references for the overhaul decision making and maintenance quality evaluation in reality. 展开更多
关键词 repairable system failure point process overhaul decision maintenance quality
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A Modified Averaging Composite Implicit Iteration Process for Common Fixed Points of a Finite Family of k-Strictly Asymptotically Pseudocontractive Mappings
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作者 Donatus Igbokwe Oku Ini 《Advances in Pure Mathematics》 2011年第4期204-209,共6页
The composite implicit iteration process introduced by Su and Li [J. Math. Anal. Appl. 320 (2006) 882-891] is modified. A strong convergence theorem for approximation of common fixed points of finite family of k-stric... The composite implicit iteration process introduced by Su and Li [J. Math. Anal. Appl. 320 (2006) 882-891] is modified. A strong convergence theorem for approximation of common fixed points of finite family of k-strictly asymptotically pseudo-contractive mappings is proved in Banach spaces using the modified iteration process. 展开更多
关键词 IMPLICIT ITERATION process k-Strictly ASYMPTOTICALLY Pseudo-Contractive Maps Fixed pointS
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RATE OF CONVERGENCE FOR MULTIPLE CHANGEPOINTS ESTIMATION OF MOVING-AVERAGE PROCESSES
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作者 Li Yunxia Zhang Lixin 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2005年第4期416-422,共7页
In this paper, the least square estimator in the problem of multiple change points estimation is studied. Here, the moving-average processes of ALNQD sequence in the mean shifts are discussed. When the number of chang... In this paper, the least square estimator in the problem of multiple change points estimation is studied. Here, the moving-average processes of ALNQD sequence in the mean shifts are discussed. When the number of change points is known, the rate of convergence of change-points estimation is derived. The result is also true for p-mixing, φ-mixing, a-mixing, associated and negatively associated sequences under suitable conditions. 展开更多
关键词 mean shift multiple change points moving-average process ALNQD least square.
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Computer Processing of the Intersection of Two Cones with Their Axes Intersecting and a Method to Get the Special Points
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作者 杨培中 《Journal of Donghua University(English Edition)》 EI CAS 2008年第2期213-217,共5页
The analytic expression of the special points on the intersection of two cones with their axes intersecting(ITCTAI) is given. It also presents a method to construct the special points graphically according to the anal... The analytic expression of the special points on the intersection of two cones with their axes intersecting(ITCTAI) is given. It also presents a method to construct the special points graphically according to the analytic expression of them. Finally, with computer programming language, it gives a program to generate the intersection in several different cases. 展开更多
关键词 ITCTAI INTERSECTION special points graphical method computer processing
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New Approach in Processing of the Infrared Image Sequence for Moving Dim Point Targets Detection
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作者 Mohamed Abdo M. Hongzuo Li 《Journal of Signal and Information Processing》 2013年第3期144-149,共6页
The development of an efficient moving target detection algorithm in IR-image sequence is considered one of the most critical research fields in modern IRST (Infrared Search and Track) systems, especially when dealing... The development of an efficient moving target detection algorithm in IR-image sequence is considered one of the most critical research fields in modern IRST (Infrared Search and Track) systems, especially when dealing with moving dim point targets. In this paper we propose a new approach in processing of the Infrared image sequence for moving dim point targets detection built on the transformation of the IR-image sequence into 4-vectors for each frame in the sequence. The results of testing the proposed approach on a set of frames having a simple single pixel target performing a different motion patterns show the validity of the approach for detecting the motion, with simplicity in calculation and low time consumption. 展开更多
关键词 IR Image SEQUENCE processING STATISTICAL processING DIM point Target DETECTION
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Standby Redundancy Allocation for a Coherent System under Its Signature Point Process Representation
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作者 Vanderlei da Costa Bueno 《American Journal of Operations Research》 2016年第6期489-501,共13页
Willing to work in reliability theory in a general set up, under stochastically dependence conditions, we intend to characterize a not identically spare standby redundancy operation through compensator transform under... Willing to work in reliability theory in a general set up, under stochastically dependence conditions, we intend to characterize a not identically spare standby redundancy operation through compensator transform under a complete information level, the physic approach, that is, observing its component lifetime. We intend to optimize system reliability under standby redundancy allocation of its components, particularly, under minimal standby redundancy. To get results, we will use a coherent system representation through a signature point process. 展开更多
关键词 RELIABILITY Martingale Methods in Reliability Theory Signature point process Standby Redundancy Coherent System
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A novel three-step implicit iteration process for threeΦ-hemicontractive mapping in the intermediate sense
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作者 Godwin Amechi Okeke Austine Efut Ofem 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2023年第2期248-263,共16页
In this paper,we introduce a three-step composite implicit iteration process for approximating the common fixed point of three uniformly continuous and asymptotically generalizedΦ-hemicontractive mappings in the inte... In this paper,we introduce a three-step composite implicit iteration process for approximating the common fixed point of three uniformly continuous and asymptotically generalizedΦ-hemicontractive mappings in the intermediate sense.We prove that our proposed iteration process converges to the common fixed point of three finite family of asymptotically generalizedΦ-hemicontractive mappings in the intermediate sense.Our results extends,improves and complements several known results in literature. 展开更多
关键词 xed point asymptotically genralizedΦ-hemicontractive mapping in the intermediate sense uniformly continuos implicit iteration process strong convergence Banach spaces
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Status of UnDifferenced and Uncombined GNSS Data Processing Activities in China
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作者 Pengyu HOU Delu CHE +3 位作者 Teng LIU Jiuping ZHA Yunbin YUAN Baocheng ZHANG 《Journal of Geodesy and Geoinformation Science》 CSCD 2023年第3期135-144,共10页
With the continued development of multiple Global Navigation Satellite Systems(GNSS)and the emergence of various frequencies,UnDifferenced and UnCombined(UDUC)data processing has become an increasingly attractive opti... With the continued development of multiple Global Navigation Satellite Systems(GNSS)and the emergence of various frequencies,UnDifferenced and UnCombined(UDUC)data processing has become an increasingly attractive option.In this contribution,we provide an overview of the current status of UDUC GNSS data processing activities in China.These activities encompass the formulation of Precise Point Positioning(PPP)models and PPP-Real-Time Kinematic(PPP-RTK)models for processing single-station and multi-station GNSS data,respectively.Regarding single-station data processing,we discuss the advancements in PPP models,particularly the extension from a single system to multiple systems,and from dual frequencies to single and multiple frequencies.Additionally,we introduce the modified PPP model,which accounts for the time variation of receiver code biases,a departure from the conventional PPP model that typically assumes these biases to be time-constant.In the realm of multi-station PPP-RTK data processing,we introduce the ionosphere-weighted PPP-RTK model,which enhances the model strength by considering the spatial correlation of ionospheric delays.We also review the phase-only PPP-RTK model,designed to mitigate the impact of unmodelled code-related errors.Furthermore,we explore GLONASS PPP-RTK,achieved through the application of the integer-estimable model.For large-scale network data processing,we introduce the all-in-view PPP-RTK model,which alleviates the strict common-view requirement at all receivers.Moreover,we present the decentralized PPP-RTK data processing strategy,designed to improve computational efficiency.Overall,this work highlights the various advancements in UDUC GNSS data processing,providing insights into the state-of-the-art techniques employed in China to achieve precise GNSS applications. 展开更多
关键词 Global Navigation Satellite Systems(GNSS) UnDifferenced and UnCombined(UDUC) Precise point Positioning(PPP) PPP-Real-Time Kinematic(PPP-RTK) single-station data processing multi-station data processing
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基于激光雷达扫描的料仓原料储料量测量方法 被引量:1
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作者 牛智有 沈柏胜 +4 位作者 路开新 徐志杰 江善晨 刘静 刘梅英 《华中农业大学学报》 CAS CSCD 北大核心 2024年第3期293-301,共9页
为提高仓内原料储料量测量自动化和智能化水平,设计了一种基于二维激光雷达扫描的储料量测量装置与系统。本系统采用RPLIDARS1型二维激光雷达扫描获取不同储料量物料的原始点云数据,通过坐标变换、重叠点提取、滤波、分割等方法对原始... 为提高仓内原料储料量测量自动化和智能化水平,设计了一种基于二维激光雷达扫描的储料量测量装置与系统。本系统采用RPLIDARS1型二维激光雷达扫描获取不同储料量物料的原始点云数据,通过坐标变换、重叠点提取、滤波、分割等方法对原始点云进行预处理,采用贪婪投影三角化算法将预处理后的点云进行三维重建,获得仓内原料的三维模型,结合物料三维模型和物料的容重获得仓内原料的储料量,从而实现储料量的自动测量。以玉米为试验对象,测量小型储料塔内玉米储料量并对玉米不同储料量进行扫描测量,验证模型的准确性,结果显示:测量结果的平均绝对误差为8.05kg,平均相对误差为1.52%。研究结果表明,基于二维激光雷达扫描的储料量测量方法是可行的,具有较好的稳定性和测量精度,能够满足实际生产需求。 展开更多
关键词 料仓 储料量 激光雷达 点云处理 三维重建
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水利工程质量监督全过程全方位定量评价模型构建 被引量:2
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作者 栾清华 王月 +2 位作者 李阳 裴梦桐 李彦苍 《南水北调与水利科技(中英文)》 CAS CSCD 北大核心 2024年第1期148-157,共10页
为促进我国水利工程质量监督管理工作运行的高效化,确保工程监督的有效性和权威性,基于AHP(analytic hierarchy process)原理,针对水利部督查小组的现场检查情况,依据水利部下达的相关文件,结合负分制和一票否决制,将定性问题定量化,构... 为促进我国水利工程质量监督管理工作运行的高效化,确保工程监督的有效性和权威性,基于AHP(analytic hierarchy process)原理,针对水利部督查小组的现场检查情况,依据水利部下达的相关文件,结合负分制和一票否决制,将定性问题定量化,构建一套涉及水利工程建设、运行、管理全过程全方位的质量监督管理评价模型,共包含7层2112个指标。在综合试错的基础上,计算得出不同层级和不同指标的权重,然后选用该模型分析评价2020年7个省份受督查水利工程项目的质量管理与安全生产管理监督数据,间接说明模型的实用性和易操作性。评价结果表明:7个省份均在合格以上,整体质量管理情况较好,但得分差异显著,其中最高得分90.6、最低得分65.6,相差25分;不同类型管理评价结果显示,安全生产管理得分普遍高于质量管理得分;各参建单位评价结果显示,建设单位和勘察设计单位的情况最优、评分基本达到满分,而质量检测单位和施工单位得分最低、需重点加强相关监管。评价结果为水利工程监督管理工作提供了科学的数据支撑,构建的评价模型也为水利工程质量监督定量化提供了易实操的普适性工具。 展开更多
关键词 水利工程 质量管理评价 层次分析法 负分制 一票否决
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Pre-process algorithm for satellite laser ranging data based on curve recognition from points cloud
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作者 Liu Yanyu Zhao Dongming Wu Shan 《Geodesy and Geodynamics》 2012年第2期53-59,共7页
The satellite laser ranging (SLR) data quality from the COMPASS was analyzed, and the difference between curve recognition in computer vision and pre-process of SLR data finally proposed a new algorithm for SLR was ... The satellite laser ranging (SLR) data quality from the COMPASS was analyzed, and the difference between curve recognition in computer vision and pre-process of SLR data finally proposed a new algorithm for SLR was discussed data based on curve recognition from points cloud is proposed. The results obtained by the new algorithm are 85 % (or even higher) consistent with that of the screen displaying method, furthermore, the new method can process SLR data automatically, which makes it possible to be used in the development of the COMPASS navigation system. 展开更多
关键词 satellite laser ranging (SLR) curve recognition points cloud pre-process algorithm COM- PASS screen displaying
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基于线结构光扫描的工件高精度三维测量方法 被引量:2
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作者 洪汉玉 吴裕强 +1 位作者 叶亮 邵洋 《武汉工程大学学报》 CAS 2024年第1期66-71,共6页
为了提高工业中对复杂轮廓工件的测量精度和效率,设计了一套高精度非接触三维测量系统,并提出了一种基于线结构光扫描的工件轮廓三维测量方法。首先,利用高精度相机和三轴移动平台采集线结构光图像。然后,通过基于差分区间的灰度质心算... 为了提高工业中对复杂轮廓工件的测量精度和效率,设计了一套高精度非接触三维测量系统,并提出了一种基于线结构光扫描的工件轮廓三维测量方法。首先,利用高精度相机和三轴移动平台采集线结构光图像。然后,通过基于差分区间的灰度质心算法,精确而高效地提取出线结构光中心线,并生成原始点云模型。接着,对采集到的点云数据进行必要的点云滤波和精简预处理。最后,将预处理后的点云数据与CAD模型精确配准,进行工件表面轮廓的测量与误差评定。实验结果表明:测量工件轮廓高度的绝对误差小于0.07 mm,相对误差小于0.5%。所提出的三维测量系统及方法测量误差较低,能够实现工件的高精度三维测量,具有一定的工业应用价值。 展开更多
关键词 线结构光 点云处理 三维测量 轮廓误差
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