Arbor Vegetation Point Cloud Filtering Processing And Accurate Earthwork Measurement In The Visible Area

At present,many engineering projects involve the issue of earthwork calculation.In addition to ground points in the point cloud data collected by a 3D laser scanner,there are also non-ground points such as vehicles,buildings,and vegetation.In order to extract ground points from the three-dimensional point cloud data,and then construct a TIN(Triangulated Irregular Network),and then calculate the amount of earthwork in the target area,it is necessary to distinguish ground points from non-ground points.Currently,the commonly used filtering algorithms include progressive encryption triangulation filtering algorithm,area growth algorithm,slope change filtering algorithm,etc.,but each algorithm has its applicability limitations.In this paper,the vegetation type that has grown arbor(relatively tall trees),with good visibility and visible bare ground underneath,carries out filtering processing to remove arbor vegetation,and proposes a filtering method of irregular triangulation filtering that integrates regional growth,and obtains the result after filtering.The ground point cloud data is used to generate the earthwork surface TIN,and then the earthwork amount in the area is accurately calculated.The main research contents of this paper are as follows:1.First take a small piece of arbor vegetation type earthwork area around the campus as an experimental study,use the three-dimensional laser scanner FARO 3D X330 to obtain the point cloud data of the target scene;then perform point cloud splicing,texture mapping,and texture mapping on the collected point cloud data.Point cloud denoising and point cloud simplification and other point cloud data processing work;According to experiments,the accuracy of splicing based on spherical targets is relatively high,up to millimeter level;the simplified sampling of point cloud data is the best for unified sampling.2.After processing the collected point cloud data of the test area,based on the idea of the irregular triangulation filtering algorithm proposed in this article,the Matlab software platform is used to filter the collected point cloud data through self-programming,To achieve the purpose of removing arbor vegetation.3.Compare the results of the filtering algorithm in this paper with the filtering results of the classic progressive encryption delta filtering algorithm proposed by ISPRS,compare the filtered data in this paper with the reference data obtained by the classic algorithm,and quantitatively evaluate the accuracy of the filtering algorithm.The filtering test results show that the error of type I in the test area is 8.5%,the error of type II is 3.7%,and the total error is 5.3%.The three types of errors of the filtering algorithm in this paper are all less than 10%,and the overall filtering effect is good.4.Use Geomagic to generate the earthwork surface TIN from the ground point cloud data obtained after filtering,and then calculate the earthwork volume of the area;use the traditional earthwork measurement method to calculate the earthwork volume for the same area,and compare the calculation result with the earthwork volume result calculated by the3 D laser scanning Perform comparison verification.The test results show that the error rate of the earthwork between the two is less than 5%,and the difference is small.