Based on the study of the application of three-dimensional laser scanning technology in ancient building surveying and mapping,this paper briefly describes the working principle and flow of three-dimensional laser sca...Based on the study of the application of three-dimensional laser scanning technology in ancient building surveying and mapping,this paper briefly describes the working principle and flow of three-dimensional laser scanning technology.Based on the practical application,this paper puts forward the discussion of related problems and matters needing attention.This has a certain reference significance for the study of new technology in surveying and mapping of ancient buildings.展开更多
Slope excavation is one of the most crucial steps in the construction of a hydraulic project. Excavation project quality assessment and excavated volume calculation are critical in construction management. The positio...Slope excavation is one of the most crucial steps in the construction of a hydraulic project. Excavation project quality assessment and excavated volume calculation are critical in construction management. The positioning of excavation projects using traditional instruments is inefficient and may cause error. To improve the efficiency and precision of calculation and assessment, three-dimensional laser scanning technology was used for slope excavation quality assessment. An efficient data acquisition, processing, and management workflow was presented in this study. Based on the quality control indices, including the average gradient, slope toe elevation, and overbreak and underbreak,cross-sectional quality assessment and holistic quality assessment methods were proposed to assess the slope excavation quality with laserscanned data. An algorithm was also presented to calculate the excavated volume with laser-scanned data. A field application and a laboratory experiment were carried out to verify the feasibility of these methods for excavation quality assessment and excavated volume calculation. The results show that the quality assessment indices can be obtained rapidly and accurately with design parameters and scanned data, and the results of holistic quality assessment are consistent with those of cross-sectional quality assessment. In addition, the time consumption in excavation quality assessment with the laser scanning technology can be reduced by 70%e90%, as compared with the traditional method. The excavated volume calculated with the scanned data only slightly differs from measured data, demonstrating the applicability of the excavated volume calculation method presented in this study.展开更多
[目的]阐明不同算法在坡面侵蚀监测中的精度和适用性,进而为土壤侵蚀过程监测算法的选择和构建提供参考。[方法]于黄土丘陵沟壑区典型流域同一自然坡面建立5个小区进行径流冲刷试验,以TLS三维点云数据为基础,通过DEM of difference(DoD)...[目的]阐明不同算法在坡面侵蚀监测中的精度和适用性,进而为土壤侵蚀过程监测算法的选择和构建提供参考。[方法]于黄土丘陵沟壑区典型流域同一自然坡面建立5个小区进行径流冲刷试验,以TLS三维点云数据为基础,通过DEM of difference(DoD)、Cloud to Cloud(C2C)、Cloud to Mesh/Model(C2M)和Multiscale Model to Model Cloud Comparison(M3C2)等方法计算侵蚀产沙量,并分析了不同算法对于侵蚀产沙的监测差异。[结果]不确定性分析结果表明:M3C2平均不确定性最小,C2C,C2M次之,DoD最大。产沙结果表明:大流量(85,70,55 L/min)下,4种算法单场次和累计场次产沙量与实测产沙量之间有显著的线性关系(R 2>0.62,p<0.05),M3C2表现最优;小流量(40,25 L/min)下,单场计算产沙量与实测产沙量之间的线性关系不显著但累计产沙量与实测产沙量之间有显著的线性关系(R 2>0.91,p<0.05),DoD表现最优。侵蚀沉积空间分布特征表明:C2C,M3C2和DoD均能反映梁峁坡和沟谷坡侵蚀发展经历的两个阶段(快速发育和稳定发育),其中M3C2能够检测到细微的地形变化,但在TLS扫描盲区,M3C2由于在法线方向上未找到对应点会出现“空洞”。[结论]M3C2算法更适合监测复杂三维地形,但在扫描盲区仍会失效,未来应改进算法,有助于应对更加复杂和剧烈的地形变化。展开更多
为提高变电站后期监测与运维管理能力,运用三维激光扫描技术,构建基于点云数据的变电站三维模型。首先,运用三维扫描设备采集变电站点云数据,通过概率统计方法、自适应密度体素滤波算法(adaptive density voxel filtering algorithm,ADV...为提高变电站后期监测与运维管理能力,运用三维激光扫描技术,构建基于点云数据的变电站三维模型。首先,运用三维扫描设备采集变电站点云数据,通过概率统计方法、自适应密度体素滤波算法(adaptive density voxel filtering algorithm,ADVFA)及基于密度的空间聚类算法(density-based spatial clustering of applications with noise,DBSCAN)对变电站点云数据集进行顶部与地面切除、压缩和去噪预处理,减少数据运行的难度与时间。其次,构建变电站电气设备点云数据快速提取方法和匹配模型,由特征编码、特征解码和特征学习3个模块组成邻域特征聚合方法对预处理后的电气设备点云数据进行分割提取,基于图像识别的快速匹配方法,完成分类设备点云与模型库设备种类的相对匹配,提高电气模型精细匹配效率。最后,通过算例分析验证所提出的基于点云数据的变电站三维建模方法的有效性和合理性。展开更多
基金Jiangxi Social Science Planning Project:Research on the Activation of Traditional Villages in Jiangxi Province from the Perspective of Cultural Conservation:A Case Study of Fuhe River Basin(Grant No.17BJ16).
文摘Based on the study of the application of three-dimensional laser scanning technology in ancient building surveying and mapping,this paper briefly describes the working principle and flow of three-dimensional laser scanning technology.Based on the practical application,this paper puts forward the discussion of related problems and matters needing attention.This has a certain reference significance for the study of new technology in surveying and mapping of ancient buildings.
基金supported by the National Natural Science Foundation of China(Grant No.51379109)
文摘Slope excavation is one of the most crucial steps in the construction of a hydraulic project. Excavation project quality assessment and excavated volume calculation are critical in construction management. The positioning of excavation projects using traditional instruments is inefficient and may cause error. To improve the efficiency and precision of calculation and assessment, three-dimensional laser scanning technology was used for slope excavation quality assessment. An efficient data acquisition, processing, and management workflow was presented in this study. Based on the quality control indices, including the average gradient, slope toe elevation, and overbreak and underbreak,cross-sectional quality assessment and holistic quality assessment methods were proposed to assess the slope excavation quality with laserscanned data. An algorithm was also presented to calculate the excavated volume with laser-scanned data. A field application and a laboratory experiment were carried out to verify the feasibility of these methods for excavation quality assessment and excavated volume calculation. The results show that the quality assessment indices can be obtained rapidly and accurately with design parameters and scanned data, and the results of holistic quality assessment are consistent with those of cross-sectional quality assessment. In addition, the time consumption in excavation quality assessment with the laser scanning technology can be reduced by 70%e90%, as compared with the traditional method. The excavated volume calculated with the scanned data only slightly differs from measured data, demonstrating the applicability of the excavated volume calculation method presented in this study.
文摘[目的]阐明不同算法在坡面侵蚀监测中的精度和适用性,进而为土壤侵蚀过程监测算法的选择和构建提供参考。[方法]于黄土丘陵沟壑区典型流域同一自然坡面建立5个小区进行径流冲刷试验,以TLS三维点云数据为基础,通过DEM of difference(DoD)、Cloud to Cloud(C2C)、Cloud to Mesh/Model(C2M)和Multiscale Model to Model Cloud Comparison(M3C2)等方法计算侵蚀产沙量,并分析了不同算法对于侵蚀产沙的监测差异。[结果]不确定性分析结果表明:M3C2平均不确定性最小,C2C,C2M次之,DoD最大。产沙结果表明:大流量(85,70,55 L/min)下,4种算法单场次和累计场次产沙量与实测产沙量之间有显著的线性关系(R 2>0.62,p<0.05),M3C2表现最优;小流量(40,25 L/min)下,单场计算产沙量与实测产沙量之间的线性关系不显著但累计产沙量与实测产沙量之间有显著的线性关系(R 2>0.91,p<0.05),DoD表现最优。侵蚀沉积空间分布特征表明:C2C,M3C2和DoD均能反映梁峁坡和沟谷坡侵蚀发展经历的两个阶段(快速发育和稳定发育),其中M3C2能够检测到细微的地形变化,但在TLS扫描盲区,M3C2由于在法线方向上未找到对应点会出现“空洞”。[结论]M3C2算法更适合监测复杂三维地形,但在扫描盲区仍会失效,未来应改进算法,有助于应对更加复杂和剧烈的地形变化。
文摘为提高变电站后期监测与运维管理能力,运用三维激光扫描技术,构建基于点云数据的变电站三维模型。首先,运用三维扫描设备采集变电站点云数据,通过概率统计方法、自适应密度体素滤波算法(adaptive density voxel filtering algorithm,ADVFA)及基于密度的空间聚类算法(density-based spatial clustering of applications with noise,DBSCAN)对变电站点云数据集进行顶部与地面切除、压缩和去噪预处理,减少数据运行的难度与时间。其次,构建变电站电气设备点云数据快速提取方法和匹配模型,由特征编码、特征解码和特征学习3个模块组成邻域特征聚合方法对预处理后的电气设备点云数据进行分割提取,基于图像识别的快速匹配方法,完成分类设备点云与模型库设备种类的相对匹配,提高电气模型精细匹配效率。最后,通过算例分析验证所提出的基于点云数据的变电站三维建模方法的有效性和合理性。
