Research On 3D Scanning Technology Based On Six-axis Manipulator

In recent years,with the continuous development of manufacturing and computer technology,3D scanning technology is one of the important means to obtain the surface data of the measured object.Its characteristics of non-contact,high precision and high efficiency have become the mainstream trend in the field of reverse modeling,and are widely used in many fields such as cultural relic protection,industrial measurement and medical diagnosis.In the industrial field,the traditional approach is to combine the line laser profilometer with the single-degree-of-freedom displacement platform to detect and measure the surface of the object,but the working space and posture are greatly limited.The 3D scanning system based on six-axis manipulator greatly improves the flexibility of the measuring system,and more comprehensively collects the 3D data and 3D model of the object to be measured.In this study,a 3D scanning system is designed,in which a line laser profiler is used as data acquisition equipment,a six-axis manipulator and an electric rotary table are used as motion equipment,and the 3D measurement and 3D reconstruction of the measured object are realized by combining point cloud processing technology and surface reconstruction technology.The main work of this thesis is as follows:(1)Firstly,the measuring principle of the line laser profilometer and the kinematics principle of the manipulator are introduced.According to the processing flow of point cloud data,the algorithm principles of statistical filtering and straight-through filtering of point cloud,point cloud data simplification and 3D surface reconstruction are introduced in detail.(2)The 3D scanning system is designed and built,the upper computer of the system is designed using Lab VIEW,the lower computer based on VAL3 language is developed to control the manipulator,and the position and orientation of the whole scanning system is calibrated and corrected in the coordinate system,so as to improve the accuracy of subsequent point cloud data acquisition and processing.(3)In order to improve the efficiency and accuracy of data acquisition,an equidistant spiral scanning strategy based on scanning depth constraint is proposed for global scanning of the measured object;Then,the sparse point area and hole area are detected according to the preliminary data,and the normal vector distribution is calculated to divide the area and supplement the data collection,and a zoning supplementary scanning strategy based on the normal vector constraint is obtained.(4)The collected point cloud data is filtered and de-noised.A sparse point detection algorithm is designed to detect the areas with poor collection effect.The voxel down sampling algorithm is improved to improve the efficiency of data reduction.The position and pose of the manipulator are calculated according to the normal vector distribution of the area to be scanned.Finally,multiple sets of data are spliced and three-dimensional surface reconstruction is performed.The 3D scanning system based on six-axis manipulator was successfully realized,which expanded the application of 3D reconstruction technology based on reverse engineering in industrial field,and has certain application significance.