1、毕业设计(论文)外文资料翻译院 系专业学生姓名班级学号外文出处指导教师评语：指导教师签名： 年 月 日外文原文Applied iterative closest point algorithm to automated inspection of gear box toothSalim Boukebbab, Hichem Bouchenitfa, Hamlaoui Boughouas, Jean Marc LinaresAbstract The development of a complete system and quality control of manufactured parts
2、requires the coordination of a set complex processes allowing data acquisition, their dimensional evaluation and their comparison with a reference model. By definition, the parts inspection is the comparison between measurements results and the theoretical surfaces definition in order to check the c
3、onformity after manufacturing phase. The automation of this function is currently based on alignment methods of measured points resulting from an acquisition process and these nominal surfaces, in a way that they “fit best”. The distance between nominal surface and measured points(i.e. form defects)
4、 calculated after alignment stages are necessary for the correction of the manufacturing parameters(Henke, Summerhays, Baldwin, Cassou, &Brown, 1999).In the work, a method for automated control based on association of complex surfaces to a cloud points using the Iterative Closest Point(I.C.P)algorit
5、hm for alignment stage is proposed. An industrial application concerning a tooth gear manufactured in our countrys tractor engines is presented.2007 Elsevier Ltd. All rights reserved. Keywords: CMMs; Complex surfaces; ICP; Gear; Manufacturing process 1. IntroductionThe design and manufacture of comp
6、lex surfaces became a current practice in industry. These surfaces can be conceived by a direct method based on the use of Computer Aided Design(CAD)software , or an indirect method which consists in a treatment of a discrete representation of an object model to obtain its CAD model. This last can b
7、e obtained throughout an acquisition process, allowing then a much more rapid safeguard, modification, manufacture, automatic inspection, prototypes checking and a much easier analysis (Lai & Ueng, 2000). The last year, the development process has covered all automated production phases, from design
8、 to the parts inspection passing by manufacture. Since the design and the manufacture of complex surfaces became a current practice in industry, then the problem related to the parts conformity are being felt more and more. The automation and the flexibility of a three-dimensional measurement machin
9、e with or without contact have made a considerable reduction in the acquisition time and the measurements treatment. In the current state of the metrology software, the inspection of elementary surfaces (plane, cylinder, cone, etc.)became a very easy practice. On the other hand the inspection of com
10、plex surfaces remains a problem to overcome (Tucker & Kurfess, 2003). The ascending complexity of parts geometry and the need for reducing production costs impose the use of more powerful tools for the inspection of complex parts surfaces, for a better service functionality description during its as
11、sembly with the conjugate mechanism parts (Tholath & Radhakrishnan, 1999). Our work is placed accordingly and consists to establish a procedure for modeling and inspecting complex parts surfaces, enabling the correction of relative deviations within production means. The method used is based on the
12、iterative-closest-point(ICP)algorithm, which is a well-known method for registering a 3D set of points to a 3D model that minimizes the sum of squared residual errors between the set and the model. This choice is motivated by the robustness of this method and it is important to underline here that;
13、no attempt to implement it within Coordinate Measuring Machines (CMMs) software has been reported in the three-dimensional metrology literature. A numerical application treating the case of a tooth of the toothed wheel which equips the gear box tractor manufactured at the engines and tractors factor
14、y in our country is presented, the comparison between the real surface obtained by acquisition and the ideal model has led to the calculation of the form defects on the two flanks of the tooth gear.2. Problems and adopted algorithm The principle of the software of Coordinate Measuring Machines consi
15、sts generally in individually associating an elementary mathematical model (plane, cylinder, etc) to each digitized surface. The function to be minimized is based on the distance di between the digitized point Mi and the theoretical surface (Fig.2). As already pointed out in the introduction, in cur
16、rent state of the metrology software, the inspection of elementary surfaces (plane, cylinder, cone, etc,) is not a problem, and most CMMs correct remaining alignment deviations numerically (alignment means to evaluate an optimum transformation T mapping the measured points to the corresponding nominal points in a way
