scholarly journals Design and Manufacture of Child Prosthesis for Higher Members Below the Elbow Through Reverse Engineering

2021 ◽  
Author(s):  
E. Pozo ◽  
E. Medina ◽  
A. Pazmiño
Keyword(s):  
Finite Elements ◽  
Reverse Engineering ◽  
Point Cloud ◽  
Geometric Model ◽  
Prosthesis Design ◽  
Design And Manufacture ◽  
Design And Construction

The objective was to build a prosthesis with its elements such as socket, forearm and hand. The prostheses that are below the elbow generated the motivation for the investigation, being an important factor the correct adaptation of the socket to the stump in a personalized way creating an adjustment due to the vacuum that is generated between these elements, without the need to use a harness. For the design and construction of the prosthesis prototype, a Kinect device was used to obtain a point cloud of the geometric model, the alginate for the manufacture of the mold and plaster that is used to obtain the shape of the hand. The result is an individualized prosthesis design built based on the patient's own dimensions and validated using finite elements; with the purpose of making changes and improvements in the design, to have a prosthesis of easy placement and use. Keywords: prosthesis, socket, stump, finite elements, kinect. Resumen El objetivo fue construir una prótesis con sus elementos como son socket, antebrazo y la mano. Las prótesis que estén por debajo del codo genero la motivación de la investigación, siendo un factor importante la correcta adaptación del socket al muñón de forma personalizada creando un ajuste debido al vacío que se genera entre dichos elementos, sin la necesidad de utilizar un arnés. Para el diseño y construcción del prototipo de prótesis, se utilizó un dispositivo Kinect para la obtención de una nube de puntos del modelo geométrico, el alginato para la fabricación del molde y yeso que es utilizado para la obtención de la forma de la mano. Se presenta como resultado un diseño individualizado de prótesis construida en base a las dimensiones propias del paciente y validado mediante elementos finitos; con el propósito de realizar cambios y mejoras en el diseño, para tener una prótesis de fácil colocación y uso. Palabras claves: prótesis, socket, muñón, elementos finitos, kinect.

Research and Practice on New Measuring and Drafting Mode of Mechanical Drawing Based on Reverse Engineering

2012 ◽  
Vol 239-240 ◽  
pp. 645-648 ◽  
Author(s):  
Dong Yang Fang ◽  
Ai Mei Zhang ◽  
Yi Qiu
Keyword(s):  
Reverse Engineering ◽  
Point Cloud ◽  
Teaching Practice ◽  
Geometric Model ◽  
Three Dimensional ◽  
Surface Shape ◽  
Modern Engineering ◽  
Innovative Idea ◽  
Part Surface ◽  
Graphics Processing

New mode of measurement and draft in mechanical drawing based on reverse engineering is presented to reflect the idea of modern engineering design on teaching practice. Traditional measurement tools are replaced by three-dimensional scanner, whereas graphics processing is performed by using CAD technology. The processing includes three steps. Firstly, point cloud of part surface shape is obtained through scanning. Secondly, point cloud images are joined, filtered and latticed in Geomagic, which is application software of CAD. Finally, the processed point cloud is imported into Catia to reconstruct surface and three-dimensional geometric model. An innovative method of measurement and draft is accordingly proposed, which combines teaching and practices and helps to cultivate the innovative idea and abilities of students.

scholarly journals Symmetry Analysis of Oriental Polygonal Pagodas Using 3D Point Clouds for Cultural Heritage

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1228
Author(s):  
Ting On Chan ◽  
Linyuan Xia ◽  
Yimin Chen ◽  
Wei Lang ◽  
Tingting Chen ◽  
...  
Keyword(s):  
Cultural Heritage ◽  
Unmanned Aerial Vehicle ◽  
Point Cloud ◽  
Geometric Model ◽  
Digital Camera ◽  
Point Clouds ◽  
Symmetry Analysis ◽  
3D Point Clouds ◽  
Transmission Towers ◽  
Aerial Vehicle

Ancient pagodas are usually parts of hot tourist spots in many oriental countries due to their unique historical backgrounds. They are usually polygonal structures comprised by multiple floors, which are separated by eaves. In this paper, we propose a new method to investigate both the rotational and reflectional symmetry of such polygonal pagodas through developing novel geometric models to fit to the 3D point clouds obtained from photogrammetric reconstruction. The geometric model consists of multiple polygonal pyramid/prism models but has a common central axis. The method was verified by four datasets collected by an unmanned aerial vehicle (UAV) and a hand-held digital camera. The results indicate that the models fit accurately to the pagodas’ point clouds. The symmetry was realized by rotating and reflecting the pagodas’ point clouds after a complete leveling of the point cloud was achieved using the estimated central axes. The results show that there are RMSEs of 5.04 cm and 5.20 cm deviated from the perfect (theoretical) rotational and reflectional symmetries, respectively. This concludes that the examined pagodas are highly symmetric, both rotationally and reflectionally. The concept presented in the paper not only work for polygonal pagodas, but it can also be readily transformed and implemented for other applications for other pagoda-like objects such as transmission towers.

User-Driven Computer-Assisted Reverse Engineering of Editable CAD Assembly Models

2021 ◽  
pp. 1-16
Author(s):  
Ghazanfar Ali Shah ◽  
Jean-Philippe Pernot ◽  
Arnaud Polette ◽  
Franca Giannini ◽  
Marina Monti
Keyword(s):  
Reverse Engineering ◽  
Point Cloud ◽  
Point Clouds ◽  
Geometric Constraints ◽  
Computer Assisted ◽  
Reconstruction Process ◽  
Mechanical Parts ◽  
Starting Point ◽  
Cad Models ◽  
Incomplete Datasets

Abstract This paper introduces a novel reverse engineering technique for the reconstruction of editable CAD models of mechanical parts' assemblies. The input is a point cloud of a mechanical parts' assembly that has been acquired as a whole, i.e. without disassembling it prior to its digitization. The proposed framework allows for the reconstruction of the parametric CAD assembly model through a multi-step reconstruction and fitting approach. It is modular and it supports various exploitation scenarios depending on the available data and starting point. It also handles incomplete datasets. The reconstruction process starts from roughly sketched and parameterized geometries (i.e 2D sketches, 3D parts or assemblies) that are then used as input of a simulated annealing-based fitting algorithm, which minimizes the deviation between the point cloud and the reconstructed geometries. The coherence of the CAD models is maintained by a CAD modeler that performs the updates and satisfies the geometric constraints as the fitting process goes on. The optimization process leverages a two-level filtering technique able to capture and manage the boundaries of the geometries inside the overall point cloud in order to allow for local fitting and interfaces detection. It is a user-driven approach where the user decides what are the most suitable steps and sequence to operate. It has been tested and validated on both real scanned point clouds and as-scanned virtually generated point clouds incorporating several artifacts that would appear with real acquisition devices.

scholarly journals A HYBRID MODEL FOR THE REVERSE ENGINEERING OF THE MILAN CATHEDRAL. CHALLENGES AND LESSON LEARNT

2021 ◽  
Author(s):  
Franco Spettu ◽  
Simone Teruggi ◽  
Francesco Canali ◽  
Cristiana Achille ◽  
Francesco Fassi
Keyword(s):  
Reverse Engineering ◽  
Point Cloud ◽  
Learning Algorithm ◽  
A Priori ◽  
Point Clouds ◽  
Logical Structure ◽  
Cloud Data ◽  
Survey Techniques ◽  
Periodic Maintenance ◽  
Maintenance And Inspection

Cultural Heritage (CH) 3D digitisation is getting increasing attention and importance. Advanced survey techniques provide as output a 3D point cloud, wholly and accurately describing even the most complex architectural geometry with a priori established accuracy. These 3D point models are generally used as the base for the realisation of 2D technical drawings and 3D advanced representations. During the last 12 years, the 3DSurveyGroup (3DSG, Politecnico di Milano) conduced an omni-comprehensive, multi-technique survey, obtaining the full point cloud of Milan Cathedral, from which were produced the 2D technical drawings and the 3D model of the Main Spire used by the Veneranda Fabbrica del Duomo di Milano (VF) to plan its periodic maintenance and inspection activities on the Cathedral. Using the survey product directly to plan VF activities would help to skip a long-lasting, uneconomical and manual process of 2D and 3D technical elaboration extraction. In order to do so, the unstructured point cloud data must be enriched with semantics, providing a hierarchical structure that can communicate with a powerful, flexible information system able to effectively manage both point clouds and 3D geometries as hybrid models. For this purpose, the point cloud was segmented using a machine-learning algorithm with multi-level multi-resolution (MLMR) approach in order to obtain a manageable, reliable and repeatable dataset. This reverse engineering process allowed to identify directly on the point cloud the main architectonic elements that are then re-organised in a logical structure inserted inside the informative system built inside the 3DExperience environment, developed by Dassault Systémes.

scholarly journals Geometric Modelling of Octagonal Lamp Poles

2014 ◽  
Vol XL-5 ◽  
pp. 145-150 ◽  
Author(s):  
T. O. Chan ◽  
D. D. Lichti
Keyword(s):  
Point Cloud ◽  
Geometric Model ◽  
Real Data ◽  
Point Clouds ◽  
Circular Cone ◽  
Basic Point ◽  
The Real ◽  
Cone Model ◽  
Proposed Model ◽  
Pole Point

Lamp poles are one of the most abundant highway and community components in modern cities. Their supporting parts are primarily tapered octagonal cones specifically designed for wind resistance. The geometry and the positions of the lamp poles are important information for various applications. For example, they are important to monitoring deformation of aged lamp poles, maintaining an efficient highway GIS system, and also facilitating possible feature-based calibration of mobile LiDAR systems. In this paper, we present a novel geometric model for octagonal lamp poles. The model consists of seven parameters in which a rotation about the z-axis is included, and points are constrained by the trigonometric property of 2D octagons after applying the rotations. For the geometric fitting of the lamp pole point cloud captured by a terrestrial LiDAR, accurate initial parameter values are essential. They can be estimated by first fitting the points to a circular cone model and this is followed by some basic point cloud processing techniques. The model was verified by fitting both simulated and real data. The real data includes several lamp pole point clouds captured by: (1) Faro Focus 3D and (2) Velodyne HDL-32E. The fitting results using the proposed model are promising, and up to 2.9 mm improvement in fitting accuracy was realized for the real lamp pole point clouds compared to using the conventional circular cone model. The overall result suggests that the proposed model is appropriate and rigorous.

Challenges and Solutions for Conductor Sharing Technology with Higher Specification Conductor to Meet Target Fatigue Life

2021 ◽  
Author(s):  
Guan Han Khor ◽  
Ezuan Hanafi Razali ◽  
M. Idham Musa ◽  
Saifol Anuar Mat Isa ◽  
Wan Helmi Wan Hasan ◽  
...  
Keyword(s):  
Fatigue Life ◽  
Wall Thickness ◽  
Oil Recovery ◽  
S Phase ◽  
Phase 3 ◽  
Working Pressure ◽  
Well Design ◽  
Design And Manufacture ◽  
Improved Technology ◽  
Design And Construction

Abstract Since Conductor Sharing Technology became prominent in the 1990s, the technology has evolved to accommodate the associated well design and construction complexities. In the redevelopment of Brownfield "S", under an alliance between PETRONAS Carigali and other operator, the technology has enabled the number of potential new wells to be increased. However, the technology has been constrained in terms of the available conductor and casing size options. The objective is to advance the current technology to meet the well design and construction requirements. This paper presents the challenges and solutions for conductor sharing technology to accommodate a higher specification conductor (36"×1.5" wall thickness), which is required to meet the fatigue life requirement in Field "S" Phase 3 redevelopment project. Since mid-2018, when PETRONAS took over the operatorship, further conductor analyses have been required. These studies confirmed the requirement for 36" conductor with 1.5" wall thickness, to meet the target fatigue life of 20 years. This paper focuses on a range of key engineering considerations related to well construction including geometrical separation, integration between CWD (casing while drilling) and directional, cementing, and diverter requirement to CWD surface casing. Since there is no existing system that can accommodate this wall thickness and still be able to meet the well construction requirements, a collaboration with the equipment provider has led to the design and manufacture of the world's first splitter wellhead system used for 36" (1.5" WT) × 13-3/8"(2X) × 9-5/8"(2X) × 3-1/2"(4X) with 10,000 psi working pressure rating. The splitter wellhead has allowed two infill wells to be drilled and completed on Platform "A". The system has maximized oil recovery with the additional well. The successful installation and production from this wellhead provide opportunity to reduce construction cost and maximize utilization of existing well slots for future development of brown fields. The improved technology has created more value by allowing surface casing to be installed by CWD in directional sections and the cementing program to be enhanced under diverter system. This solution will be beneficial to similar brown fields which have limited remaining slots and where it is unjustifiable to construct a new platform. In addition, it provides opportunity to lower the wellhead platform cost for green fields by optimizing the number of well slots and platform design.

Design and Manufacturing of Customized Braces for Scoliosis Treatment

2002 ◽  
Author(s):  
H. Wu ◽  
D. Xue ◽  
J. Harder ◽  
J. L. Ronsky ◽  
P. Poncet ◽  
...  
Keyword(s):  
Geometric Model ◽  
Milling Machine ◽  
Cnc Milling ◽  
Optical Scanning ◽  
Cnc Milling Machine ◽  
Design And Manufacturing ◽  
Scoliosis Treatment ◽  
Noise Data ◽  
Thermoforming Process ◽  
Design And Manufacture

A new method to design and manufacture customized braces is introduced in this research for scoliosis treatment. In this method, a geometric model of a scoliosis patient’s torso is achieved using a laser optical scanning device. The brace geometry is obtained by generating the offset geometry of the torso’s surface, selecting vertical boundaries, removing holes and noise data, creating symmetrical geometry, and modifying the geometry near the pelvis curves. Manufacturing of the brace is conducted by producing a male die with a sculptured surface using a custom-designed 5-axis CNC milling machine and creating the plastic brace using a thermoforming process.

The Use of the Terrestrial Photogrammetry in Reverse Engineering Applications

2015 ◽  
Vol 4 (2) ◽  
pp. 48-57
Author(s):  
Naci Yastikli ◽  
Zehra Erisir ◽  
Pelin Altintas ◽  
Tugba Cak
Keyword(s):  
Reverse Engineering ◽  
Point Cloud ◽  
Low Cost ◽  
Line Drawing ◽  
Engineering Application ◽  
3D Models ◽  
Engineering Applications ◽  
Ship Model ◽  
Dense Point ◽  
Terrestrial Photogrammetry

The reverse engineering applications has gained great momentum in industrial production with developments in the fields of computer vision and computer-aided design (CAD). The reproduction of an existing product or a spare part, reproduction of an existing surface, elimination of the defect or improvement of the available product are the goals of industrial reverse engineering applications. The first and the most important step in reverse engineering applications is the generation of the three dimensional (3D) metric model of an existing product in computer environment. After this stage, many operations such as the preparation of molds for mass production, the performance testing, the comparison of the existing product with other products and prototypes which are available on the market are performed by using the generated 3D models. In reverse engineering applications, the laser scanner system or digital terrestrial photogrammetry methods, also called contactless method, are preferred for the generation of the 3D models. In particular, terrestrial photogrammetry has become a popular method since require only photographs for the 3-dimensional drawing, the generation of the dense point cloud using the image matching algorithms and the orthoimage generation as well as its low cost. In this paper, an industrial application of 3D information modelling is presented which concerns the measurement and 3D metric modelling of the ship model. The possible usage of terrestrial photogrammetry in reverse engineering application is investigated based on low cost photogrammetric system. The main aim was the generation of the dense point cloud and 3D line drawing of the ship model by using terrestrial photogrammetry, for the production of the ship in real size as a reverse engineering application. For this purpose, the images were recorded with digital SLR camera and orientations have been performed. Then 3D line drawing operations, point cloud and orthoimage generations have been accomplished by using PhotoModeler software. As a result of the proposed terrestrial photogrammetric steps, 0.5 mm spaced dense point cloud and orthoimage have been generated. The obtained results from experimental study were discussed and possible use of proposed methods was evaluated for reverse engineering application.

Research Based on Reverse Engineering Technology of Complex Structure Product

2015 ◽  
Vol 741 ◽  
pp. 806-809
Author(s):  
Ai Qin Lin ◽  
Yong Xi He
Keyword(s):  
Reverse Engineering ◽  
Point Cloud ◽  
Complex Structure ◽  
Laser Scanner ◽  
Complex Surface ◽  
Curved Surface ◽  
Quality Model ◽  
High Quality ◽  
Engineering Technology ◽  
Working Principle

Introduced reverse engineering technology and working principle. Researched reverse design process of the complex curved surface "spider". The data were collected by means of multiple scanning measuring with laser scanner. Used Geomagic Studio software for date point cloud processed of complex curved surface. Used UG software for surface reconstruction designed. Product reduction and improvement of the design were finished rapidly and high quality. Model of spider was printed with rapid prototyping technology. Compared with physical, the model’s reliability and accuracy were verified by reverse engineering design.Keywords: complex surface; reverse engineering technology; UG; Geomagic Studio software

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