ALGORITHM OF PRETREATMENT ON AUTOMOBILE BODY POINT CLOUD参考.doc

CHINESE JOURNAL OF MECHANICAL ENGINEERING GAO Feng ZHOUYu DU Farong QU Weiwei XIONGYonghua Department of Automobile Engineering, Beihang University, Beijing , China  ALGORITHM OF PRETREATMENT ON AUTOMOBILE BODY POINT CLOUD* Abstract: As point cloud of one whole vehicle body has the traits of large geometric dimension, huge data and rigorous reverse precision, one pretreatment algorithm on automobile body point cloud is put forward. The basic idea of the registration algorithm based on the skeleton points is to construct the skeleton points of the whole vehicle model and the mark points of the separate point cloud, to search the mapped relationship between skeleton points and mark points using congruence triangle method and to match the whole vehicle point cloud using the improved iterative closed point (ICP) algorithm. The data reduction algorithm, based on average square root of distance, condenses data by three steps, computing datasets average square root of distance in iw.^pling: cube ￡rd, sorting order according to the value computed from the first stop, choosing sampling percentage. Tfe accuracy of the two algorithms above is proved by a registration and reduction exiuvple of whole vehicle point cloud of a certain light truck. Key voros: Reverst; engineering Paint cloud registration Skeleton point iterative closed point(ICP) Data reduction  0 INTRODUCTION In reverse engineering system, the point cloud registration and the data reduction are two crucial cruxes of the point cloud pretreatment. The precision of registration and quality of reduction can affect the outcome of surface reconstruction significantly. The hypostasis of point cloud registration is to find proper mapping relation among several preparative registration point clouds and achieve iterative solution by coordinate transforming. The traditional registration algorithm is mainly divided into two categories: the geometry matching algorithm and the pinpoint registration algorithm. Geome