Reverse Engineering of Geometric Surfaces Using Tabu Search Optimization Technique

Author(s):  
Ayman M. A. Youssef ◽  
Ashraf O. Nassef ◽  
Sayed M. Metwalli

Creating unavailable geometric models from existing parts plays an important role in the process of reverse engineering, for which the accuracy and fitting time of the created models are important factors. This paper proposes the use of Tabu Search (TS) technique in the optimal fitting of NURBS (Non Uniform Rational B-Spline) surfaces to laser-scanned point clouds of free-form surfaces for existing parts. The fitting process involves the initial estimation of the NURBS surface control points using least-squares approximation, followed by optimization of NURBS weights to minimize fitting error. Optimization is performed using a hybrid coding scheme, namely; Modified Continuous Reactive Tabu Search (M-C-RTS), in which a combinatorial optimization component, based on Reactive Tabu Search (RTS), co-operates with Sequential Quadratic Programming (SQP), as a local minimizer. The developed fitting algorithm was applied to a number of simulated free-form surfaces in addition to a laser-scanned PC mouse. Implementation was carried out using MATLAB software and the results were compared to those obtained using Genetic Algorithms (GAs) in an earlier publication. The results show the superiority of the proposed algorithm to the GA-based method with respect to the number of objective function evaluations (about 50% reduction). In addition to this time saving achievement, and surprisingly, M-C-RTS proved to be capable of finding better solutions than GAs.

2001 ◽  
Vol 40 (3) ◽  
pp. 215-227 ◽  
Author(s):  
Lai Xinmin ◽  
Lin Zhongqin ◽  
Huang tian ◽  
Zeng Ziping

2016 ◽  
Vol 63 (4) ◽  
pp. 647-663
Author(s):  
Vimal Kumar Pathak ◽  
Chitresh Nayak ◽  
Amit Kumar Singh ◽  
Himanshu Chaudhary

Abstract Computer-aided tools help in shortening and eradicating numerous repetitive tasks that reduces the gap between digital model and actual product. Use of these tools assists in realizing free-form objects such as custom fit products as described by a stringent interaction with the human body. Development of such a model presents a challenging situation for reverse engineering (RE) which is not analogous with the requirement for generating simple geometric models. Hence, an alternating way of producing more accurate three-dimensional models is proposed. For creating accurate 3D models, point clouds are processed through filtering, segmentation, mesh smoothing and surface generation. These processes help in converting the initial unorganized point data into a 3D digital model and simultaneously influence the quality of model. This study provides an optimum balance for the best accuracy obtainable with maximum allowable deviation to lessen computer handling and processing time. A realistic non trivial case study of free-form prosthetic socket is considered. The accuracy obtained for the developed model is acceptable for the use in medical applications and FEM analysis.


Author(s):  
C. Jepping ◽  
F. Bethmann ◽  
T. Luhmann

This paper deals with the correction of exterior orientation parameters of stereo image sequences over deformed free-form surfaces without control points. Such imaging situation can occur, for example, during photogrammetric car crash test recordings where onboard high-speed stereo cameras are used to measure 3D surfaces. As a result of such measurements 3D point clouds of deformed surfaces are generated for a complete stereo sequence. The first objective of this research focusses on the development and investigation of methods for the detection of corresponding spatial and temporal tie points within the stereo image sequences (by stereo image matching and 3D point tracking) that are robust enough for a reliable handling of occlusions and other disturbances that may occur. The second objective of this research is the analysis of object deformations in order to detect stable areas (congruence analysis). For this purpose a RANSAC-based method for congruence analysis has been developed. This process is based on the sequential transformation of randomly selected point groups from one epoch to another by using a 3D similarity transformation. The paper gives a detailed description of the congruence analysis. The approach has been tested successfully on synthetic and real image data.


2014 ◽  
Vol 664 ◽  
pp. 263-267
Author(s):  
Feng Lu ◽  
Ning Li ◽  
Xiao Fei Zhang

To deal with the lack of accurate and efficient inspection methods in complex free-form surfaces, three-dimensional measurement method based on the optical measurement and computer image processing technology was proposed. It adopted laser scanning technology to get point clouds of free-form surface. Used rapid measurement software to inspect precision of point cloud& CAD model. What could be the cause of machining errors was analyzed. 3D deviation inspection of complex surfaces was applied by an artifact. Detected the machining error of an important section, and outputted test report. This research provides a convenient and swift method for the inspection of free-form surface and processing quality control.


2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Xue Ming He ◽  
Jun Fei He ◽  
Mei Ping Wu ◽  
Rong Zhang ◽  
Xiao Gang Ji

To seek better methods of measurement and more accurate model of reconstruction in the field of reverse engineering has been the focus of researchers. Based on this, a new method of adaptive measurement, real-time reconstruction, and online evaluation of free-form surface was presented in this paper. The coordinates and vectors of the prediction points are calculated according to a Bézier curve which is fitted by measured points. Final measured point cloud distribution is in agreement with the geometric characteristics of the free-form surfaces. Fitting the point cloud to a surface model by the nonuniform B-spline method, extracting some check points from the surface models based on grids and a feature on the surface, review the location of these check points on the surface with CMM and evaluate the model, and then update the surface model to meet the accuracy. Integrated measurement, reconstruction, and evaluation, with the closed-loop reverse process, established an accurate model. The results of example show that the measuring points are distributed over the surface according to curvature, and the reconstruction model can be completely expressed with micron level. Meanwhile, measurement, reconstruction and evaluation are integrated in forms of closed-loop reverse system.


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