Path Planning For Three-dimensional Line Scanning Robots

In this thesis, a path planning method for inspection of complex surfaces withscanning systems based on industrial robots is studied, and the main contentsinclude:(1) read and display of CAD data in IGES format;(2) selection of thesurface to be inspected, and computation of its relevant information;(3) pathplanning for complex surfaces with the three-dimensional line laser scanner, andpath simulation and verification using simulation software for industrial robots.This thesis is divided into seven chapters.In the first chapter, the state of the art in this field is introduced, and anindustrial robot scanning system is presented. All the algorithms in this thesis aredeveloped for this system. Then, the significance of this study is analyzed, andfinally the main contents of this thesis are introduced.In the second chapter, the definitions and properties of curves and surfaces aswell as some basic algorithms are introduced to provide a theoretical basis forcurve and surface processing in the following chapters.In the third chapter, read and display methods for the CAD data file in IGESformat, including the structure analysis of an IGES file, the functions of each part,the read process of the file, and display method after reading the file, areintroduced.In the fourth chapter, selection and information computation method for thecomplex surface are introduced. The selection mechanism of OpenGL is used topick up the surface to be inspected, and sample points on the surface and normalvectors at these points are computed. A new method for computing sample points isput forward to meet the features of the three-dimensional line laser scanner. In thismethod, the sample points are computed by the intersection of a specified plane anda set of isoparametric curves on the surface. Meanwhile, a method is proposed toeliminate redundant sample points.In the fifth chapter, a series of position and orientation that is required to scanthe surface are computed using the concept of visual cone and considering theparameters of the three-dimensional line laser scanner as well. Then these positionsconnected with a Zigzag path to get the optimal scanning path.In the sixth chapter, the path computed in the fifth chapter is converted into an executable file for industrial robots, and the path is simulated and occlusion andcollision are analyzed.The thesis is concluded with a summary and the future work prospect in theseventh chapter.