An investigation for improvement of the 3D‐digitization process: a reverse engineering approach

Abstract

Purpose -The purpose of this paper is to provide a comprehensive work flow for the improvement of the Reverse Engineering (RE) process in producing non-uniform rational B-splines (NURBS) models from scanned point cloud data. This should become a reliable guide in the creation of desired 3D-CAD models in order to improve efficiency of downstream operations and further to make decisions regarding quality control. Design/methodology/approach -The paper deals with a detailed investigation of operations in achieving an object's accuracy in the data editing phase and data fitting phase that employs the use of a 3D scanner. A case example involving the ShapeGrabberw AI310 laser scanner was used in digitizing the physical object. Operations considered for investigation at the data editing phase include relaxation, decimation of triangles and sharpening of edges. Contour detection, construct patches, target patch count, grid construction and grid resolution are selected as the operations for investigation in the data fitting phase. Evaluation of the generated digitized models was carried out by performing tests which include 3D Comparisons and Geometric Dimensioning and Tolerance (GD & T) testing. Findings -The process of data editing is considered to be extremely time consuming which requires a high degree of skill in order to carry out the data manipulation steps. For the purpose of investigation, an electrical socket cover was considered as the object for digitization. The study found some contributors to enhance the quality of the digital model that can be used in the first piece inspection. The results indicate that although the operations associated with the data fitting phase affect the overall quality of the digitized model; they are however, limited by whatever the quality achieved at the data editing phase. Practical implications -The RE work flow described in this research will assist designers and practitioners in improving both the efficiency and effectiveness of design and manufacturing functions. Originality/value -The data editing and fitting processes are time consuming due to various adjustments necessary in obtaining a NURBS model from the digitized data. Thus, the proposed RE work flow identified the steps to realize the desired CAD models from the point cloud data. Moreover, from this study, practitioners will get a concise overall understanding about which geometrical features need to be adjusted so that the required model can be achieved; instead of the need to develop this procedure by themselves through the process of trial and error.

An integrated design approach for rapid product development

“…The RE workflow involves the sequential development of discrete models at the data acquisition, data capture, data editing and data fitting phases (Chowdary et al, 2011). These include: physical object, point cloud model, polygon model, surface model, and digitized parametric CAD model.…”

“…Data acquisition of the physical object commences with implementation of the RE process as proposed in Chowdary et al (2011). Retrieval of missing part data for the broken clutch shoe was accelerated through a non-contact digitization method known as laser triangulation (Várady et al, 1996).…”

“…In the generated triangular mesh model, errors such as intersections and holes were detected and repaired manually. It is imperative to resolve these deficiencies before proceeding to development of the parametric CAD model as the created polygon mesh embodies the rough surface of the periphery defining the shape of the object (Chowdary et al, 2011). Moreover, the existence of these deficiencies prevents the construction of a superior non-uniform rational B-splines (NURBS) model (Ali et al, 2009).…”

An Integrated Approach for Design and Manufacture of Plastic Products

“…The reconstruction of digital geometric models of physical objects, usually indicated as RE in the CAD field, has been extensively studied in recent years, due to the development and spreading of 3D scanning technologies and the increase in number of appropriate applications [1][2][3][4][5][6]. RE in fact, exploit 3D data acquired on the physical object and describing its surfaces as starting point for the reconstruction framework [1,2,7]. Many researchers have contributed to the ReE area demonstrating its usefulness to leverage the product design and development process.…”

“…In addition, RE subject area has been widely recognized as being a substantial step in the product development process. Other applications of RE include recovery of damaged or broken part, the design of a new component and a simulation model [1,2,7]. Sovilj-Nikic et al [11] measured roughness parameters of surfaces of the hob milling tools using the measuring device "MahrSurf PS1".…”