scholarly journals Development of Support System for Ship-Hull Plate Forming Using Laser Scanner

2021 ◽  
Vol 15 (3) ◽  
pp. 290-300
Author(s):  
Masahito Takezawa ◽  
◽  
Kohei Matsuo ◽  
Takahiro Ando
Keyword(s):  
Point Cloud ◽  
Laser Scanner ◽  
Target Surface ◽  
Ship Hull ◽  
B Spline ◽  
Spline Surface ◽  
Lines Of Curvature ◽  
Plate Shape ◽  
The Difference ◽  
Ship Hull Plate

In this study, we developed a new system that outputs the additional press work procedures necessary to obtain the desired ship-hull surface. This study is unique in terms of determining the additional press work procedures required according to the current plate shape at any work stage by measuring the plate shape using a laser scanner. In the proposed method, a B-spline surface is constructed from a point cloud measured using a laser scanner, and the current plate shape is analyzed based on differential geometry. Additional press lines are estimated based on the difference in the normal curvature along the lines of curvature between the designed target surface and the current surface. We demonstrated the effectiveness of our proposed method through experiments at a shipyard. The proposed system may be used to enhance the efficiency of press work and is expected to be an effective tool for training beginners in the future.

Sticking Paint Replacement Films on Ship Hull Surfaced based on Lines of Curvature

2019 ◽  
Author(s):  
M Takezawa ◽  
K Matsuo
Keyword(s):  
Shape Optimization ◽  
Nonlinear Optimization ◽  
Thin Sheet ◽  
Ship Hull ◽  
Surface Shape ◽  
Bulk Carrier ◽  
B Spline ◽  
Original Surface ◽  
Lines Of Curvature ◽  
Curvature Lines

In this paper, we propose a new concept of using the paint replacement films covering a ship-hull surface instead of paint based on lines of curvature. Firstly, we correct the B-spline hull surface within the prescribed deviation from the original surface shape based on nonlinear optimization to smooth the flow of curvature lines. After shape optimization, we adjust the position and the number of curvature lines so that it becomes the surface developments suitable for applying to thin sheet films. Using our method, it is possible to stick the films on the hull surface with few wrinkles. Finally, we applied proposed techniques to a bow of a bulk carrier to demonstrate the effectiveness of our algorithms.

scholarly journals Tank Modeling and Its Condition Assessment using Terrestrial Laser Scanner

2021 ◽  
Vol 936 (1) ◽  
pp. 012004
Author(s):  
Irwan Gumilar ◽  
Samuel Van Livtrik Lumban Gaol ◽  
Made Munarda ◽  
Brian Bramanto ◽  
Agus Lukmanulhakim
Keyword(s):  
Data Processing ◽  
Point Cloud ◽  
Good Condition ◽  
Laser Scanner ◽  
Condition Assessment ◽  
American Petroleum Institute ◽  
Terrestrial Laser Scanner ◽  
Cloud Data ◽  
Data Assessment ◽  
The Difference

Abstract Condition assessment of the tank must be carried out since it is related to Health, Safety, and Environment (HSE). Assessment is carried out by referring to the applicable standards. This study aims to create a 3D (Dimension) model and assess the tank using Terrestrial Laser Scanner technology. This includes planning, data acquisition, data processing, and data visualization. The data processing process starts with the registration stage with the cloud-to-cloud method, georeferencing, 3D modeling using point cloud, and tank assessment filtered point cloud data. Assessment includes analysis of volume, verticality/slope (in terms of the difference between upper and lower tank), and roundness calculations. The 3D model of the tank was generated with a registration error of less than 1 cm. The volume of tank I and tank II were calculated to 134.108 m3 and 134.067 m3, respectively. The difference between the upper and lower radius for each tank ranges from 2 to 10 mm. Considering the results and recalling the API 650 standard (American Petroleum Institute), each tank is considered reliable and in a good condition.

Ship-hull geometry representation with B-spline surface patches

1992 ◽  
Vol 24 (4) ◽  
pp. 217-222 ◽  
Author(s):  
L. Bardis ◽  
M. Vafiadou
Keyword(s):  
Ship Hull ◽  
B Spline ◽  
Surface Patches ◽  
Spline Surface

Ship hull plate processing surface fairing with constraints based on B-spline

2005 ◽  
Vol 4 (3) ◽  
pp. 13-17 ◽  
Author(s):  
Liu Yu-jun ◽  
Zhu Xiu-li ◽  
Ji Zhuo-shang
Keyword(s):  
Ship Hull ◽  
B Spline ◽  
Ship Hull Plate

scholarly journals Representation of 3D Environment Map Using B-Spline Surface with Two Mutually Perpendicular LRFs

2015 ◽  
Vol 2015 ◽  
pp. 1-14 ◽  
Author(s):  
Rui-Jun Yan ◽  
Jing Wu ◽  
Ji Yeong Lee ◽  
Chang-Soo Han
Keyword(s):  
Point Cloud ◽  
Three Dimensional ◽  
Complex Problem ◽  
Experimental Result ◽  
Data Set ◽  
B Spline ◽  
Spline Surface ◽  
3D Environment ◽  
Spline Surfaces ◽  
Continuous Rotation

This paper proposes a map representation method of three-dimensional (3D) environment by using B-spline surfaces, which are first used to describe large environment in 3D map construction research. Initially, a 3D point cloud map is constructed based on extracted line segments with two mutually perpendicular 2D laser range finders (LRFs). Then two types of accumulated data sets are separated from the point cloud map according to different types of robot movements, continuous translation and continuous rotation. To express the environment more accurately, B-spline surface with covariance matrix is proposed to be extracted from each data set. Due to the random movements, there must be overlap between extracted B-spline surfaces. However, merging of two overlapping B-spline surfaces with different distribution directions of their control points is a complex problem, which is not well addressed by far. In our proposed method, each surface is divided into overlap and nonoverlap. Then generated sample points with propagated uncertainties from one overlap and their projection points located on the other overlap are merged using the product of Gaussian probability density functions. Based on this merged data set, a new surface is extracted to represent the environment instead of the two overlaps. Finally, proposed methods are validated by using the experimental result of an accurate representation of an indoor environment with B-spline surfaces.

A Fast Grid Deformation Algorithm for Aerodynamic Shape Optimization

2010 ◽  
Author(s):  
Kaveh Mohamed ◽  
Kurt Sermeus ◽  
Eric Laurendeau
Keyword(s):  
Optimization Problems ◽  
Flow Simulation ◽  
Surface Model ◽  
Initial Surface ◽  
Surface Mesh ◽  
B Spline ◽  
Mesh Movement ◽  
Spline Surface ◽  
The Difference ◽  
Volume Mesh

A mesh movement algorithm suitable for aerodynamic design optimization problems is presented. It involves B-spline surface construction, projection and evaluation on B-spline faces for the surface mesh movement, as well as inverse-distance and 2D/3D TFI interpolations for the volume mesh deformation. The algorithm is fast and exhibits an excellent parallel efficiency. It is used to deform the surface and volume mesh of an ONERA-M6 wing undergoing several planform changes. The quality of the deformed mesh is preserved as long as the difference between the initial surface mesh and the B-spline surface model is small. A good agreement reported between the flow simulation results on the deformed mesh and those obtained on initial fixed mesh.

Results of studying the dimensional accuracy of the bases of complete removable prostheses made using 3D printing and traditional technologies

2020 ◽  
pp. 34-39
Author(s):  
Vokulova Yu.A. Vokulova ◽  
E.N. Zhulev
Keyword(s):  
3D Printing ◽  
Traditional Method ◽  
Laser Scanning ◽  
Laser Scanner ◽  
Digital Technologies ◽  
Dimensional Accuracy ◽  
3D Printer ◽  
Significance Level ◽  
Average Value ◽  
The Difference

This article presents the results of studying the dimensional accuracy of the bases of complete removable prostheses made using a 3D printer and the traditional method. Bases of complete removable prostheses were made using an intraoral laser scanner iTero Cadent (USA) and a 3D printer Asiga Max UV (Australia). To study the dimensional accuracy of the bases of complete removable prostheses, we used the DentalCAD 2.2 Valletta software. The Nonparametric Wilcoxon W-test was used for statistical analysis of the obtained data. We found that the average value of the difference with the standard for bases made using digital technologies is 0.08744±0.0484 mm. The average value of the difference with the standard for bases made by the traditional method is 0.5654±0.1611 mm. Based on these data, we concluded that the bases of complete removable prostheses made using modern digital technologies (intraoral laser scanning and 3D printer) have a higher dimensional accuracy compared to the bases of complete removable prostheses made using the traditional method with a significance level of p<0.05 (Wilcoxon's W-test=0, p=0.031). Keywords: digital technologies in dentistry, digital impressions, intraoral scanner, 3D printing, ExoCAD, complete removable dentures.

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