Abstract：To solve the problem that the scan results of the ring scan sonar are affected by the sound of mixed water in the drainage pipe, a method for denoising the point cloud data of the sonar scan is proposed. On the basis of the three-dimensional point cloud data obtained by the ring scan sonar, the density clustering optimization algorithm (DBSCAN) is used to remove the noise in the point cloud data. Then, the method of fitting the slope of the outer tangent of the circle is used to identify the boundary of the inner wall of the pipeline and the silt deposition line, and finally obtain a model including the boundary of the inner wall of the drainage pipe and the characteristics of the silt line. To verify the effectiveness, a drainage pipeline in Wuhan is taken as an example for analysis, and performs data denoising and feature extraction based on 980000 point cloud coordinates collected on site. The results show that after the initial screening of the point cloud data using the density clustering optimization algorithm, the SFA-COT can effectively identify the inner wall boundary and the siltation line of the drainage pipe. The mean square error of the fitting radius is 0.0071m, which has higher fitting accuracy and better denoising effect than the single density clustering algorithm.
吴俊豪,李琛,王蓉,刘文黎,周星宇. 基于密度聚类和圆外切线斜率拟合的埋地排水管道声呐点云去噪技术[J]. 计量学报, 2023, 44(2): 231-237.
WU Jun-hao,LI Chen,WANG Rong,LIU Wen-li,ZHOU Xing-yu. The Slope Fitting Method of Sonar Point Cloud on the Inner Wall of Sewer Based on Density Algorithm and Tangent Slope Fitting of the Circle. Acta Metrologica Sinica, 2023, 44(2): 231-237.
Ma M H, Wang H X, Jia P F, et al. Investigation of inducements and defenses of flash floods and urban waterlogging in Fuzhou, China, from 1950 to 2010 ［J］. Natural Hazards, 2018, 91(2): 803-818.
［3］
Petit-Boix A, Arnal C, Marin D, et al. Addressing the Life Cycle of Sewers in Contrasting Cities through an Eco-Efficiency Approach ［J］. Journal of Industrial Ecology, 2018, 22(5): 1092-1104.
Wang C H, Wang A Y, Rong W, et al. Adaptive Denoising Algorithm for Photon-Counting LiDAR Point Clouds ［J］. Laser & Optoelectronics Progress, 2021, 58(14): 482-489.
Fu B W, Jin P K, Shi S, et al. Sediment Characteristics of Sewer Network in Xi an City ［J］. China Water & Wastewater, 2018, 34(17): 119-122, 127.
［9］
Ester M, Kriegel H P, Sander J, et al. A Density-Based Algorithm for Discovering Clusters in Large Spatial Databases with Noise ［J］. AAAI Press, 1996, 96(34): 226-231.
Guo Y X, Xu H D, Xie W, et al. Exploration and Practice of Combined Sewer Overflow Pollution Control in Old Urban Area Based on Sponge City Concept ［J］. China Water & Wastewater, 2019, 35(14): 1-6.
Zhang M, Zhang Z J, Feng J Q, et al. Density peak clustering algorithm based on adaptive reachable distance ［J］. Journal of Computer Applications, 2022, 42(6): 8.
［14］
Sander J, Ester M, Kriegel H P, et al. Density-based clustering in spatial databases: The algorithm GDBSCAN and its applications ［J］. Data Mining and Knowledge Discovery, 1998, 2(2): 169-194.
Bao J S, Dong H L, Yin Y, et al. Experimental analysis on alternating magnetic field to suppress friction noise of brake ［J］. Journal of Vibration Engineering, 2021, 34(4): 838-848.
Guo X L, Zheng F F, Ma C M, et al. GPR-based leak detection technology in water pipelines: principle and phenomenon mechanism ［J］. Journal of Hydraulic Engineering, 2021, 52(7): 781-792.
Zhang Y C, Li Y B, Fu X B. Point Cloud Segmentation De-noising Method Based on Curvature Constraint ［J］. Acta Metrologica Sinica, 2020, 41(10): 1218-1225.
Xiao Q, Wang J R, Chen H, et al. The detection and evaluation by CCTV and rehabilitation analysis of sewer pipeline in an area of Shenzhen City ［J］. Water & Wastewater Engineering, 2019, 55(9): 109-114.
［10］
Rodriguez A, Laio A. Clustering by fast search and find of density peaks ［J］. Science, 2014, 344(6191): 1492-1496.
［16］
Nurunnabi A, Sadahiro Y, Laefer D F. Robust statistical approaches for circle fitting in laser scanning three-dimensional point cloud data ［J］. Pattern Recognition, 2018, 81: 417-431.
Ye X T, Zhao P, Zheng K, et al. Research on Underwater Hull Surface Imaging Method Based on Ultrasonic Phased Array ［J］. Acta Metrologica Sinica, 2020, 41(1): 79-84.
2023, Vol. 44 
