Research On The Construction Of Point Cloud Model Of Open Pit Dump And Its Edge Warning Line Extraction

With the development of intelligent mine,the application of many intelligent equipment,especially the assembling of unmanned vehicles in open-pit mines,saves a lot of manpower and material resources.At the same time,it also puts forward higher requirements for the current open-pit load-transport-unloading environment awareness system.Open pit dump is the place where ore waste is discharged centrally,and the dump data information is the important basis of open pit mine truck transportation.With the continuous progress of the dumping operation of the open pit dump,the dump edge will change dynamically.This change makes it difficult to accurately determine the benchmark line for safe dumping in open-pit mines called the dumping edge warning line.Dumping safety accidents may occur when the open pit mine card judges the wrong dumping area.How to extract the dumping edge warning line of high-precision open-pit mines has become the key to safe dumping operations in open-pit mines and the realization of automatic dumping operations by unmanned vehicles in open-pit mines.Based on the data of dump point cloud collected by 3D laser scanning technique,the paper studies the construction of dump point cloud model and the extraction of dump edge warning line in open-pit mines.The main work is as follows:(1)In view of the problems of high noise and large amount of data in the collected point cloud data of open-pit mine dumps,denoising and simplification algorithms are used to complete the preprocessing of point cloud data.In order to deal with the noise existing in the point cloud data of the dump site,the performance of two denoising algorithms based on spatial distribution and based on bilateral filtering on the simulation data of the dump site was studied.In order to reduce the redundant information in the point cloud data,three point cloud simplification algorithms based on random sampling,based on bounding box and based on curvature were compared on the simplification effect of soil dump simulation data.(2)To meet the visualization requirements of open-pit mine dump site safety monitoring and dump vehicle scheduling model,this paper obtains the NURBS interpolation curve by interpolating the point cloud data of the open-pit mine dump site,and then fits the NURBS interpolation curve to obtain the dump site point cloud model.In addition,the modeling time and modeling accuracy of the method to build the simulation model of the dump are also analyzed.(3)To solve the problem of finding the optimal dump line for open-pit mine trucks in the dump,an algorithm for removing the edge of the dump in open-pit mine was proposed.This method selects the dumping plane data through the angle between the normal vector of the point cloud data and the horizontal plane and calculates the dumping plane equation,then uses the soil dumping plane equation to segment the point cloud data around the dumping edge line,and finally fits the surrounding data of the dumping line Form the dumping edge warning line.(4)Based on the data of a coal mine dump in Inner Mongolia,the algorithm proposed in this paper is applied as an example.Firstly,the airborne 3D laser scanner was used to collect and preprocess the point cloud data of the dump.Secondly,the point cloud model of the dump site is constructed and the warning line of the dump edge is extracted.Thirdly,a quantitative analysis of the constructed model and the extracted dumping edge warning line was performed.Finally,the dumping edge warning line was used to provide a safe dumping area for the open pit mine.In this paper,the use of 3D lidar scanning technology to study the open pit dump and dump edge can not only provide a new method for related scholars to study this direction,but also reduce the occurrence of safety accidents in open pit dump.