A new method for designing and machining air compressor screw pairs

2020 ◽  
Vol 34 (22n24) ◽  
pp. 2040128
Author(s):  
Long Hoang ◽  
Tien Long Banh ◽  
Tuan-Linh Nguyen
Keyword(s):  
3D Model ◽  
3D Models ◽  
High Accuracy ◽  
New Method ◽  
Air Compressor ◽  
Industrial Manufacturing ◽  
Disk Tool ◽  
Air Compressors ◽  
Model Pair

Screw air compressors have been being used widely for 45 years. There are many research works on these machines, but there have been still many problems, especially on designing and machining their screw pair, to study. This paper focuses on gate screw profiling from the main screw profile and disc tool profiling for manufacturing the screw pair. The air compressor screw 3D model pair, designed by using the proposed methods, have satisfied the meshing condition. The disc tool 3D models created for machining the screws have also been tested in many ways, these testing results show high accuracy of the disk tool 3D model, which can be used in industrial manufacturing.

Research on the Inspection Information Extraction from 3D Models of Sheet Metal Parts by the Photoelectric Equipments

2013 ◽  
Vol 446-447 ◽  
pp. 486-490
Author(s):  
Li Wei Zhao ◽  
Dong Wang ◽  
Bo Hao ◽  
Li He
Keyword(s):  
Information Extraction ◽  
Sheet Metal ◽  
3D Model ◽  
High Efficiency ◽  
3D Models ◽  
High Accuracy ◽  
Inspection Method ◽  
Metal Parts ◽  
Sheet Metal Parts ◽  
Actual Shape

The short comings and limitations of traditional inspection method of sheet metal parts were described in this paper. Aiming at the inspection method based on the 3D models of sheet metal parts, the method of the inspection information extraction was introduced also. The actual shape of the sheet metal was obtained by the portable photoelectric equipments and then the 3D model was formed. The inspection information was extracted from the 3D model by the system which developed by VC++ tools on the CATIA platform. The characteristics of this method are high accuracy, environmental protection and high efficiency.

scholarly journals WORKFLOW FOR AN EVIDENCE-BASED VIRTUAL RECONSTRUCTION: THE MARBLES OF THE CIBORIUM OF THE EARLY MEDIEVAL MONTE SORBO CHURCH

2020 ◽  
Vol XLIII-B2-2020 ◽  
pp. 1395-1402
Author(s):  
E. C. Giovannini
Keyword(s):  
3D Model ◽  
3D Models ◽  
High Accuracy ◽  
3D Modelling ◽  
Evidence Based ◽  
Visual Appearance ◽  
Architectural Elements ◽  
Digital Integration ◽  
Virtual Reconstruction ◽  
Great Possibility

Abstract. The paper presents a practical approach to define a hypothetical virtual reconstruction of the ciborium and pergola of Monte Sorbo's Church. The high accuracy of archaeological fragments, digitally acquired, allowed to hypothesize the entire sequences of decorations of architectural elements and to define their geometrical rules. Starting from the acquisition to the 3d modelling phase, the proposed virtual reconstruction combines original fragments with their lost parts modelled in a digital environment.Digital technologies offer nowadays the great possibility to visualize and understand cultural heritage in a new and attractive way. Digital models and virtual reconstructions have a key role in encouraging and promoting the development of good practices for recording, documenting, and making accessible scientific processes beyond visual appearance. The term virtual reconstruction, within the project, is used to describe a procedure that consists of making a 3D model that reproduces a digital copy of the original, assembling digitally acquired fragments with elements philologically reconstructed following the evidence-based geometrical rules. This study aims to contribute to this growing area of research by exploring possibilities on digital integration of different 3d models to re-define a visual appearance of lost architectural elements.

scholarly journals Stellar magnetic imaging from spectropolarimetric data

1996 ◽  
Vol 176 ◽  
pp. 53-60 ◽  
Author(s):  
J.-F. Donati
Keyword(s):  
Small Amplitude ◽  
High Accuracy ◽  
Spectral Lines ◽  
New Method ◽  
Doppler Imaging ◽  
Magnetic Imaging ◽  
Active Stars ◽  
Surface Fields ◽  
Very High

In this paper, I will review the capabilities of magnetic imaging (also called Zeeman-Doppler imaging) to reconstruct spot distributions of surface fields from sets of rotationnally modulated Zeeman signatures in circularly polarised spectral lines. I will then outline a new method to measure small amplitude magnetic signals (typically 0.1% for cool active stars) with very high accuracy. Finally, I will present and comment new magnetic images reconstructed from data collected in 1993 December at the Anglo-Australian Telescope (AAT).

A Design of High-Accuracy Displacement Measurement Instrument from Principles of Optics

2012 ◽  
Vol 170-173 ◽  
pp. 2924-2928
Author(s):  
Sheng Biao Chen ◽  
Yun Zhi Tan
Keyword(s):  
Measurement Instrument ◽  
High Accuracy ◽  
Mechanical Tests ◽  
Total Reflection ◽  
Displacement Measurement ◽  
New Method ◽  
Water Volume ◽  
Water Drainage ◽  
Accuracy Of Measurement ◽  
Better Than

In order to measure the water drainage volume in soil mechanical tests accurately, it develop a new method which is based on principles of optics. And from both physical and mathematic aspects, it deduces the mathematic relationship between micro change in displacement and the increment projected on screen. The result shows that total reflection condition is better than refraction condition. What’s more, the screen could show the water volume micro variation clearly, so it can improve the accuracy of measurement.

scholarly journals Barycentric prolate interpolation and pseudospectral differentiation

2021 ◽  
Author(s):  
Yan Tian
Keyword(s):  
Boundary Value Problem ◽  
Convergence Rates ◽  
Boundary Value ◽  
High Accuracy ◽  
Second Order ◽  
New Method ◽  
Numerical Examples ◽  
Helmholtz Problem ◽  
Collocation Scheme

AbstractIn this paper, we provide further illustrations of prolate interpolation and pseudospectral differentiation based on the barycentric perspectives. The convergence rates of the barycentric prolate interpolation and pseudospectral differentiation are derived. Furthermore, we propose the new preconditioner, which leads to the well-conditioned prolate collocation scheme. Numerical examples are included to show the high accuracy of the new method. We apply this approach to solve the second-order boundary value problem and Helmholtz problem.

A New Method for Aggregate Proportion Design of Mixture

2012 ◽  
Vol 178-181 ◽  
pp. 1250-1253
Author(s):  
Yu Hua Li ◽  
Kai Huang ◽  
Ying Zhen Gao
Keyword(s):  
Iterative Algorithm ◽  
Accurate Result ◽  
High Accuracy ◽  
New Method ◽  
Equation Method ◽  
Normal Equation ◽  
Improved Method ◽  
Mixture Ratio ◽  
Target Value ◽  
Initial Target

When we make design of mixture ratio, we always use normal equation method (NEM), but the solution value of that method may doesn’t meet our demand. When we use the new method that proposed in this paper, we can solve the problem. The new method makes an improvement for NEM. By iterative algorithm, the new method uses the gradation data calculated by NEM as initial target value, canceling the relevant aggregate if the result of proportion is negative, and setting the gradation to the boundary value if the target value goes beyond limits. According to the adjusted object value, using NEM again, the new aggregate proportion can be solved. Then the new gradation of mixture will come into being the next target value. Finally, the accurate result will meet our need. The new improved method has good engineering applicability and high accuracy

Research on Construction of Semantic Web of 3D Model Database

2012 ◽  
Vol 532-533 ◽  
pp. 1263-1267
Author(s):  
Hui Jia ◽  
Guo Hua Geng ◽  
Jin Xia Yang
Keyword(s):  
Semantic Web ◽  
3D Model ◽  
3D Model Retrieval ◽  
New Method ◽  
Three Dimension ◽  
Semantic Extension ◽  
Model Retrieval ◽  
Semantic Relevance ◽  
Model Database

This paper presented a new method to construct semantic web of three-dimension model database based on ontology. Firstly we build ontology of three-dimension model database, according the model to extract classes, objects and attributes. Secondly utilize WordNet which is an English ontology to expand original ontology node to semantic extension node, including synonym, hypernym, hyponym and holonym. Experiment result shows that this method not only effectively expands the semantic vocabularies of a 3D model database, but also keeps good semantic relevance of the expanded vocabularies to the original ones, so as to achieve semantic based 3D model retrieval effectively.

Adaptive Verspannung von Zahnstange-Ritzel-Antrieben*/Adaptive preloading for rack-and-pinion-drives

2019 ◽  
Vol 109 (05) ◽  
pp. 312-318
Author(s):  
T. Engelberth ◽  
A. Verl
Keyword(s):  
Machine Tools ◽  
Energy Demand ◽  
High Accuracy ◽  
Drive System ◽  
New Method ◽  
Large Machine ◽  
Production Facilities

Zahnstange-Ritzel-Antriebe werden vorwiegend in großen Werkzeugmaschinen eingesetzt. Um die hohen Genauigkeitsanforderungen moderner Produktionsanlagen zu erreichen, werden diese Antriebe elektrisch verspannt. Die Verspannung ist konstant. Dieser Beitrag beschreibt eine neuartige Methode, die sogenannte adaptive Verspannung. Ziel ist es, den Energiebedarf und die Belastung des Antriebssystems durch Anpassung der Verspannung während des Betriebs zu reduzieren, ohne die Genauigkeit zu beeinflussen.   Rack-and-pinion-drives are mostly used in large machine tools. To achieve the high accuracy specifications of modern production facilities, these drives are electrically preloaded. The preload is constant. This article describes a new method of so-called adaptive preloading. The aim is to reduce energy demand and wear of the drive system by adjusting the preload during operation without affecting the accuracy.

scholarly journals UNDERWATER PHOTOGRAMMETRY DIGITAL SURFACE MODEL (DSM) OF THE SUBMERGED SITE OF THE ANCIENT LIGHTHOUSE NEAR QAITBAY FORT IN ALEXANDRIA, EGYPT

2019 ◽  
Vol XLII-2/W10 ◽  
pp. 1-8 ◽  
Author(s):  
M. Abdelaziz ◽  
M. Elsayed
Keyword(s):  
3D Model ◽  
Low Cost ◽  
Data Gathering ◽  
Archaeological Site ◽  
3D Models ◽  
Surface Model ◽  
Digital Surface Model ◽  
Architectural Elements ◽  
3D Photogrammetry ◽  
First Time

<p><strong>Abstract.</strong> Underwater photogrammetry in archaeology in Egypt is a completely new experience applied for the first time on the submerged archaeological site of the lighthouse of Alexandria situated on the eastern extremity of the ancient island of Pharos at the foot of Qaitbay Fort at a depth of 2 to 9 metres. In 2009/2010, the CEAlex launched a 3D photogrammetry data-gathering programme for the virtual reassembly of broken artefacts. In 2013 and the beginning of 2014, with the support of the Honor Frost Foundation, methods were developed and refined to acquire manual photographic data of the entire underwater site of Qaitbay using a DSLR camera, simple and low cost materials to obtain a digital surface model (DSM) of the submerged site of the lighthouse, and also to create 3D models of the objects themselves, such as statues, bases of statues and architectural elements. In this paper we present the methodology used for underwater data acquisition, data processing and modelling in order to generate a DSM of the submerged site of Alexandria’s ancient lighthouse. Until 2016, only about 7200&amp;thinsp;m<sup>2</sup> of the submerged site, which exceeds more than 13000&amp;thinsp;m<sup>2</sup>, was covered. One of our main objectives in this project is to georeference the site since this would allow for a very precise 3D model and for correcting the orientation of the site as regards the real-world space.</p>

scholarly journals FROM ARCHIVE DOCUMENTATION TO ONLINE 3D MODEL VISUALIZATION OF NO LONGER EXISTING STRUCTURES: THE TURIN 1911 PROJECT

2020 ◽  
Vol XLIII-B2-2020 ◽  
pp. 837-844
Author(s):  
D. Einaudi ◽  
A. Spreafico ◽  
F. Chiabrando ◽  
C. Della Coletta
Keyword(s):  
Cultural Heritage ◽  
3D Model ◽  
3D Models ◽  
World's Fair ◽  
Existing Structures ◽  
Present Generation ◽  
Technical Issues ◽  
Digital Documentation ◽  
3D Documentation ◽  
Model Visualization

Abstract. Rebuilding the past of cultural heritage through digitization, archiving and visualization by means of digital technology is becoming an emerging issue to ensure the transmission of physical and digital documentation to future generations as evidence of culture, but also to enable present generation to enlarge, facilitate and cross relate data and information in new ways. In this global effort, the digital 3D documentation of no longer existing cultural heritage can be essential for the understanding of past events and nowadays, various digital techniques and tools are developing for multiple purposes.In the present research the entire workflow, starting from archive documentation collection and digitization to the 3D models metrically controlled creation and online sharing, is considered. The technical issues to obtain a detail 3D model are examined stressing limits and potentiality of 3D reconstruction of disappeared heritage and its visualization exploiting three complexes belonging to 1911 Turin World’s Fair.

Sign in / Sign up

Export Citation Format

Share Document