Surface Reconstruction Technology Research Articles

Research on laser measurement point cloud preprocessing and 3D reconstruction technology for free-form surfaces.

Surface morphology measurement and reconstruction technology based on point cloud data is one of the key technologies for 3D information processing in the digital manufacturing industry and has been widely applied in fields such as reverse engineering, computer vision, and unmanned driving system navigation. A method for 3D modeling of aircraft-engine blade profiles based on laser measurement point cloud data is proposed to address the difficulties in measuring the 3D morphology of aircraft-engine blades and the low modeling accuracy. This method first preprocesses the measured point cloud and then uses Poisson's algorithm to reconstruct the blade surface in three dimensions based on the calculation of the point cloud normal. Through error statistical analysis, the overall reconstruction effect is good. The experimental results further validated the generality and effectiveness of this method.

Isogeometric degenerated shell formulation for post-buckling analysis of composite variable-stiffness shells

Variable-stiffness (VS) laminated shells with curved fibers have gradually become a promising lightweight structural concept in the aerospace field. However, as the complexity of the shell geometry and the fiber angle increases, the traditional finite element method (FEM) requires mesh refinement to guarantee accurate discretization, which significantly increases the computational cost, especially in the post-buckling analysis with multiple solving requirements. In this study, a non-uniform rational B-Splines (NURBS)-based degenerated solid shell formulation in the total Lagrangian framework is proposed for the post-buckling analysis of VS laminated shells. Since the nonlinear function related to the rotational degrees of freedom (DOFs) is additionally introduced into the displacement field expression, the restriction on the magnitude of the nodal rotations is effectively eliminated. In addition, the paper adopts the NURBS surface reconstruction technology based on the point-line-surface features to build B-spline CAD models from the point cloud with geometric imperfect features. Then, an integrated modeling-analysis framework for predicting the post-buckling behavior of VS structures with geometric imperfections is proposed. A series of numerical examples systematically demonstrate that the framework can effectively conduct the post-buckling analysis of shell structures with geometric imperfections. Meanwhile, the accuracy and robustness of the solutions by IGA are proved to be better than FEM.

Steady-state and dynamic performances of journal bearing based on rough surface reconstruction technology

Steady-state and dynamic performances of journal bearing based on rough surface reconstruction technology

Study on Sliding Wear Characteristics of Non-Gaussian Rough Surface in Mixed Lubrication

Under mixed lubrication, when there is direct rough contact between two contact surfaces, surface wear occurs, altering surface morphology, which in turn changes their lubrication state. The tribological performance of materials can be improved with in-depth understanding of the coupling mechanism linking surface wear and lubrication. A numerical model was established to predict the lubrication state and wear characteristics of the surface wear process based on non-Gaussian surface reconstruction technology and a mixed elastohydrodynamic lubrication sliding wear model. The evolution of wear characteristics in Gaussian and non-Gaussian rough surfaces was investigated, and the effect of surface skewness and kurtosis on lubrication and wear characteristics was discussed. The results indicated that as the wear cycle increases, the contact area and contact load ratios of the rough surfaces decrease before gradually stabilizing, while the coefficient of friction and maximum flash temperature rise and then gradually decrease. Increasing surface skewness and kurtosis increases the probability of wear, leading to increased accumulated wear, friction coefficient, and maximum flash temperature rise.

Prediction of the tribological characteristics of non‐Gaussian rough surfaces during sliding wear in mixed lubrication

AbstractIn mixed lubrication, material wear is inevitably caused due to solid contact. Simultaneously, the surface morphology after wear will affects the lubrication performance. To understand this coupling process, virtual surface reconstruction technology and mixed lubrication sliding wear model were applied to predict the evolution of wear characteristics and lubrication characteristics during wear in this study. The effects of the roughness root mean square (RMS), roughness direction and wavelength ratio on the contact area ratio, the contact load ratio, accumulated wear, film thickness and the friction coefficient were analysed. The results indicated that the contact area ratio and the contact load ratio and the friction coefficient decreased and average film thickness increased with the increase in the number of the wear cycles. In addition, a surface with low‐roughness RMS, longitudinal roughness texture and high‐wavelength ratio is suitable for improving lubrication performance and reducing wear.

High-precision surface reconstruction technology for elliptical flat mirrors

The predecessor of China Optics was China Optics and Applied Optics Digest, which was founded in 1985. At that time, it was the only retrieval journal in the field of optics in China. At the end of 2008, China Optics and Applied Optics Digest was renamed

Surface Reconstruction Pattern Recognition Technology Based on Scattered Point Cloud Data.

Surface reconstruction technology based on cloud data has broad prospects in the fields of reverse engineering, cultural heritage protection, and smart city construction. This article studies the surface reconstruction pattern recognition technology based on scattered point cloud data. The candidate feature points are extracted according to the surface variation, and the precise method of point cloud is used to fit the clustering plane, and the feature points are selected from the candidate feature points. Use the area increase method to construct the initial grid of the specific three-dimensional point group data. In the construction process, the normal vector of the point group data does not need to be separated, but defines the angle of the normal vector of the adjacent triangular grids, thereby separating relatively flat areas. Using the projection parameterization method, the scattering points in the domain are projected onto the curved surface, and the parameter values of the projection points are counted as the parameter values of the scattering points. All sampling points on the common boundary have tangent vectors along the two directions of the boundary. The direction of the bisector of the angle between the two tangent vectors is calculated as the direction of the connection vector outside the boundary of the sampling point. It can be seen from the experimental data that the search radius of the normal vector and feature descriptor when calculating the feature description operator is 0.01 and 0.02 m, instead of 0.005 and 0.006 m of the bunny data. Using the local feature size to refine the point cloud data can reduce the number of point clouds, remove redundant data in the point cloud, and realize dynamic adjustment and adaptive reconstruction of nonuniform point clouds.

In-situ reconstruction of spinel interface on Li-rich layered cathode with improved electrochemical performances

The produced inactive interface during the cycle and poor rate performance are the inevitable obstacles for the practicability of lithium-rich layered cathode. Here, we report that in-situ surface pretreatment technique with hydrazine hydrate can reconstruct epitaxial spinel possessing the rapid lithium ions diffusion path, which primarily includes the leaching of Li+/Ni2+ and redistribution of the metal ions. We confirm the generation of epitaxial spinel heterostructure on the layered matrix by kinds of characterization methods such as transmission electron microscopy and Raman spectroscopy. As a result, the epitaxial spinel substantially promotes the lithium ion diffusion coefficient from 1.98 × 10−11 cm2 s−1 to 3.76 × 10−11 cm2 s−1. Even under a discharge current 5 C, the reversible capacity still reaches up to 171.1 mAh g−1. After 200 cycles at 1 C, the modified cathode delivers a capacity retention of 84.2% with the discharge capacity of 197.8 mAh g−1. The presence of the epitaxial spinel layer exerts a positive effect on the stability of the cathode structure and suppression of side reactions at the interface via exploring the morphology and composition of the cycled cathodes. The in-situ surface reconstruction technology to generate spinel is appealing for promise prospect application of lithium-rich layered cathodes in the future.

A Survey of Surface Reconstruction Techniques for Line Structured Light Systems

Reverse engineering has been widely used in industrial production, and surface reconstruction technology is the most important part of reverse engineering. Line structure measurement is a non-contact surface measurement method with high precision, low destructiveness, high data acquisition efficiency and strong anti-interference. This paper focuses on the measurement principle of line structured light, system calibration, strip center extraction and point cloud data processing and surface reconstruction. Finally, the existing surface reconstruction techniques that are widely used are summarized.

An Improved RANSAC Surface Reconstruction Study

Surface reconstruction technology has always been an important research area in graphic image. However, efficiently processing massive amounts of high-precision point cloud data is still a problem worth studying. Based on the characteristics of point cloud data and the existing research results, this paper proposes a RANSAC algorithm based on voxel segmentation and applies it to 3D surface reconstruction. By analyzing the characteristics of the original point cloud data, the method improves the reconstruction speed of the 3D model while retaining a large amount of effective feature information and ensuring high precision. The experimental results show that compared with the reconstruction algorithm based on the original RANSAC algorithm, the proposed algorithm can effectively reduce the surface reconstruction time of 47.51%, and the model error after processing is only one thousandth compared with the original model.

Three-dimensional Acoustic Target Surface Reconstruction Method Based on Marching Cubes

Marching Cubes is an isosurface reconstruction algorithm based on volume data. In order to solve the problems of low resolution, rough surface, insufficient texture and stereo sense in the process of three-dimensional acoustic target’s visualization, a method based on Marching Cubes is used to reconstruct the surface of three-dimensional acoustic target in this paper. By constructing the minimal cube in acoustic data field, determining the connection mode, vertex coordinates and normal vectors of triangle elements in the cube where the target contour lies, we establish the target’s three-dimensional surface model, and the reconstruction of three-dimensional acoustic target is realized. The performance and validity of the method are validated by the sea trial data from three-dimensional imaging sonar, and the performance of the method is tested by multi-resolution data, and a three-dimensional surface model of buried target is constructed based on the sea trial data. The results show that the surface reconstruction technology of three-dimensional acoustic target based on marching cubes algorithm has the advantages of simple structure and less computation, and the time-consuming of the algorithm is proportional to the number of sampling points. In the process of three-dimensional acoustic image visualization, surface reconstruction technology can effectively improve the stereo sense and recognition of buried targets.

Fatigue life prediction of workpiece with 3D rough surface topography based on surface reconstruction technology

The fatigue performance of a workpiece depends on its surface quality. In traditional fatigue life prediction, the effect of surface quality is commonly accounted for by using empirical correction factors, which is imprecise when safety is of great concern. For surface quality, the surface topography is an important parameter, which introduces stress concentration that reduces the fatigue life. It is not feasible to test the stress concentration of different surface topographies. On the one hand, it is time-consuming and high-cost, and on the other hand, it cannot reflect the general statistical characteristics. With the help of surface reconstruction technology and interpolation method, a more efficient and economic approach is proposed, where FE simulation of workpiece with the reconstructed surface topography is used as a foundation for fatigue life prediction. The relationship between surface roughness (Sa) and fatigue life of the workpiece is studied with the proposed approach.

Novel Method for Virtual Restoration of Cultural Relics with Complex Geometric Structure Based on Multiscale Spatial Geometry

Because of the age of relics and the lack of historical data, the geometric forms of missing parts can only be judged by the subjective experience of repair personnel, which leads to varying restoration effects when the geometric structure of the complex relic is reconstructed. Therefore, virtual repair effects cannot fully reflect the historical appearance of cultural relics. In order to solve this problem, this paper presents a virtual restoration method based on the multiscale spatial geometric features of cultural relics in the case of complex construction where the geometric shape of the damaged area is unknown, using the Dazu Thousand-Hand Bodhisattva statue in China as an example. In this study, the global geometric features of the three-dimensional (3D) model are analyzed in space to determine the geometric shape of the damaged parts of cultural relics. The local geometric features are represented by skeleton lines based on regression analysis, and a geometric size prediction model of the defective parts is established, which is used to calculate the geometric dimensions of the missing parts. Finally, 3D surface reconstruction technology is used to quantitate virtual restoration of the defective parts. This method not only provides a new idea for the virtual restoration of artifacts with complex geometric structure, but also may play a vital role in the protection of cultural relics.

Role of 3D reconstruction in the evaluation of patients with lower segment oesophageal cancer.

Three-dimensional (3D) reconstruction has been used in evaluating the lungs and liver, but there is only little research on the application of 3D reconstruction for the oesophagus. This research aims to study the application of 3D reconstruction in patients with lower segment oesophageal tumours to improve the diagnosis and treatment of oesophageal cancer and to provide a better method of preoperative assessment. All the patients were treated at the First Hospital of Jilin University between January 2014 and August 2015 for oesophageal cancer. We collected the patients' imaging data and used surface reconstruction technology to reconstruct their oesophageal tumours and adjacent structures. Tumour shape and other specific parameters were analysed and calculated, and comparisons of the results from different conditions of 3D reconstruction were made. IBM SPSS 19.0 was used to analyse all the data. All the data were averaged over three measurements. The t-test was used to compare the mean of the two groups, and variance analysis was used among the groups, where P<0.05 indicated a significant difference. Of the 72 patients, there were 48 cases in which a gastroscope was able to pass through the oesophageal lesion and 24 cases where this was not possible. The location of the lesion ranged from 30 to 42 cm among those 48 cases. The endoscopic measurement length and the 3D length were both longer than the pathological length (P<0.05), but there was no significant difference between the endoscopic measurement length and the 3D length. In the reconstructed data of positive lymph nodes, the length, diameter, volume, CT value and reconstruction of the lymph nodes in the negative group were significantly different compared with the positive group. The application of 3D reconstruction in oesophageal cancer is safe and effective. 3D reconstruction plays an important role in preoperative evaluation of tumours and the surrounding lymph nodes and may be useful for evaluation of the long-term efficacy of radiotherapy and chemotherapy for oesophageal cancer.

Surface Reconstruction Adopting Laser Plane of Linear Path System Registered by Parallel Constraint

A surface reconstruction technology, which is contributed from the parallel constraint between two laser planes, is introduced and achieved by a laser projector guided by a linear path system. The projection geometry is constructed by the projection planes, the target planes, the laser planes, the image planes, and the intersection lines. First, the angle between the direction of the projector translation and the normal vector of the laser plane is contributed by the bilinear product operator of the intersection line and the projection matrix. Second, the distance errors are generated from the points on two laser planes and parameterized by the angle and the laser plane for the optimization. Finally, the surface reconstruction is realized by the optimized angle and laser plane. The experiments are conducted to prove the validity of the surface measurement method. The mean of the reconstruction errors is 0.78 mm in the test, which indicates the application potentials from the experimental investigations.

The Data Acquisition, Process and Reconstruction for a Reverse Engineering Study

As a modern design method that contrary to traditional design, RE technology use of special measuring apparatus to get dimensional data and enables one to start a design from an existing production model by combining computer technology, measurement technology and CAD/CAM technology. Firstly, The author has list the important application fields of RE technology, and then divided the RE process into four steps and described the detailed working flowchart. The data acquisition procedure includes datum-points creation and model measurement. For the threedimensional coordinate measuring machine, a contact measurement, the measuring method and working principal is deep discussed. As to the acquired data, the data processing should also be operated to meet the technique requirement, which consists of data splicing, noise eliminating, data interpolating, data smoothing and data filtering. Finally, the author summarized the surface reconstruction technology with the well data and assumed the RE technology will have more extensively application in mechanical fields.

Reverse Engineering Application in Automobile Parts Design

Along with the development of the measuring technique and computer technology, market competition is aggravating, the modern product of the design cycle demands shorter especially in automobile field. In order to meet the development requirements of automobile, we must reduce the design cycle and cost, so the Reverse Engineering (RE) technique has applications widely. This paper describes some concepts about reverse engineering. It points out the key technologies in reverse engineering like cloud data processing technology and surface reconstruction technology. Finally this paper uses the reverse engineering software CATIA to recover one inner automobile panel and describes the process of reverse engineering in details to build 3D model.

Surface models of the male urogenital organs built from the Visible Korean using popular software

Unlike volume models, surface models, which are empty three-dimensional images, have a small file size, so they can be displayed, rotated, and modified in real time. Thus, surface models of male urogenital organs can be effectively applied to an interactive computer simulation and contribute to the clinical practice of urologists. To create high-quality surface models, the urogenital organs and other neighboring structures were outlined in 464 sectioned images of the Visible Korean male using Adobe Photoshop; the outlines were interpolated on Discreet Combustion; then an almost automatic volume reconstruction followed by surface reconstruction was performed on 3D-DOCTOR. The surface models were refined and assembled in their proper positions on Maya, and a surface model was coated with actual surface texture acquired from the volume model of the structure on specially programmed software. In total, 95 surface models were prepared, particularly complete models of the urinary and genital tracts. These surface models will be distributed to encourage other investigators to develop various kinds of medical training simulations. Increasingly automated surface reconstruction technology using commercial software will enable other researchers to produce their own surface models more effectively.