Key Technologies And Applications Of Real Scene Reverse Modeling Of Bridge Components Based On 3D Point Cloud Model

Since the 21st century,with the rapid development of transportation technology,the increasing traffic volume,vehicle load increased significantly,the bridge service condition deteriorated,plus bridge "aging",conditions,the material degradation,construction defects,a large number of problems in the operational phase of bridge diseases,increasing safety accident.In order to ensure the safe operation of existing and newly built Bridges,it is very important to detect and evaluate the actual state of Bridges quickly and accurately.At the same time,the existing bridge basically only has the design drawings and models,the lack of complete and accurate completion model and operation model.This brings some difficulties to the maintenance and reconstruction of the following Bridges.At present,the spatial morphology acquisition of Bridges in operation mainly relies on artificial observation methods and traditional measuring instruments.These methods and instruments have low efficiency and high working intensity,and their detection results are greatly affected by the knowledge level and subjective judgment of the detection personnel,and their reliability is low.In recent years,bridge inspection and evaluation and management technology is developing rapidly towards industrialization,information and intelligence.3D laser scanning technology not only breaks through the traditional single point measurement method,but also can directly and quickly obtain massive 3D coordinate data of object surface.It has the advantages of high measurement efficiency,high degree of automation,low working intensity of detection personnel,large amount of data and high data processing efficiency.Compared with the traditional measurement technology,it has a broad application prospect.The 3d point cloud data collected by 3d laser scanner can present the point coordinate information of the measured object surface in the form of 3D point cloud model,which is intuitive and easy to read.Therefore,3d laser scanning technology can quickly obtain the spatial configuration information of bridge structure,and provide a guarantee for reverse modeling based on bridge real scene.The point cloud model obtained directly from the scanning of bridge components has limited application,and it often has many problems,and the mass data points have a high degree of dispersion to the geometric information of components.In order to improve the applicability of component point cloud model,it is necessary to carry out a series of processing to the point cloud model.In this paper,a complete method of real scene reverse modeling of bridge components based on 3D point cloud model is proposed,and the reverse modeling of two engineering cases is carried out using this method.Firstly,the point cloud models of various bridge components obtained by 3D laser scanner are summarized and analyzed,and the problems existing in the three-dimensional point cloud of bridge components in typical environments are summarized.Then for some of the common problems is proposed based on optimal placement of the station and based on scanning the point cloud of auxiliary props quality improvement methods,at the same time,three of the most common problem for point clouds,in view of the high frequency noise is proposed based on neighboring points spatial relations of the high frequency noise filtering algorithm,in view of the low frequency noise is proposed based on improved bilateral filter low-frequency noise smoothing algorithm,A point cloud integrity improvement algorithm based on Delaunay triangle and minimum curvature is proposed to improve the quality of point cloud significantly.Finally,a reverse modeling algorithm based on bridge component skeleton extraction is proposed to generate a threedimensional solid model that can reflect the real spatial state of the bridge from the high quality point cloud preprocessed,and verified by two engineering examples.A series of methods proposed in this paper have the advantages of high efficiency and high precision.They can be applied to the point cloud of bridge components at the level of ten million points to obtain the spatial state of bridge components during scanning,and provide a real basis for the safe operation,maintenance and reinforcement of bridges.