The Synthesis, Designing and Analysis of the Spatial Mechanisms with Imposed Constraints

2015 ◽  
Vol 756 ◽  
pp. 495-499 ◽  
Author(s):  
Alexey Fomin

The present study provides structural synthesis, designing of 3D models and kinematic analysis of the developed spatial one-and two-movable mechanisms with imposed constraints. These mechanisms have an opportunity of technological application as mechanisms for cutting the complex internal surfaces of machine elements. The mechanisms produce a special kind of screw motion which is the most suitable means for cutting of complex spatial surfaces. Structural synthesis was based on mathematical solution of universal structural system where numbers of kinematic pairs and movable links were calculated. 3D-modelling analysis allowed to identify motion paths of their output links with machining tools. This investigation results gave an opportunity to analyze the tools motion, optimize their constructions and use of relevant parameters, and design their motions to obtain specified surfaces of machine elements.

Author(s):  
Agnieszka Chmurzynska ◽  
Karolina Hejbudzka ◽  
Andrzej Dumalski

During the last years the softwares and applications that can produce 3D models using low-cost methods have become very popular. What is more, they can be successfully competitive with the classical methods. The most wellknown and applied technology used to create 3D models has been laser scanning so far. However it is still expensive because of the price of the device and software. That is why the universality and accessibility of this method is very limited. Hence, the new low cost methods of obtaining the data needed to generate 3D models appeare on the market and creating 3D models have become much easier and accessible to a wider group of people. Because of their advantages they can be competitive with the laser scanning. One of the methods uses digital photos to create 3D models. Available software allows us to create a model and object geometry. Also very popular in the gaming environment device – Kinect Sensor can be successfully used as a different method to create 3D models. This article presents basic issues of 3D modelling and application of various devices, which are commonly used in our life and they can be used to generate a 3D model as well. Their results are compared with the model derived from the laser scanning. The acquired results with graphic presentations and possible ways of applications are also presented in this paper.


Author(s):  
Luis Marques ◽  
Josep Roca

The creation of 3D models of urban elements is extremely relevant for urbanists constituting digital archives and being especially useful for enriching maps and databases or reconstructing and analyzing objects/areas through time, building/recreating scenarios and implementing intuitive methods of interaction. The widespread data available online offer new opportunities to generate realistic 3D models without the need to go physically to the place. This chapter aims to demonstrate the potential 3D modeling and visualization/interaction of urban elements in the city for multiple purposes, and it is organized in four main topics: The first deals with the theoretical framework regarding the bases of the human perception of the spatial environment and the importance of 3D modelling. The second and third deal with technical procedures on terrestrial/aerial data acquisition and demonstrate alternatively data gathered online to generate 3D models for the visualization of urban elements of the city, and the fourth introduces 3D model visualization within an augmented reality environment.


2017 ◽  
Vol 62 (No. 4) ◽  
pp. 204-210 ◽  
Author(s):  
S. Ozkadif ◽  
E. Eken ◽  
MO Dayan ◽  
K. Besoluk

This study was undertaken to obtain and analyse, on the basis of sex, three-dimensional (3D) reconstructions obtained by a 3D computer program from two-dimensional (2D) vertebral column sections taken by multidetector computed tomography (MDCT) images, in the chinchilla. A total of 16 adult chinchillas (Chinchilla lanigera) of both sexes were used. The MDCT images were taken under general anaesthesia, and were then transferred to a personal computer on which 3D reconstructions were carried out using a 3D modelling program (Mimics 13.1). The volume, surface area and vertebral body length of each vertebra (except caudal region) forming the vertebral column were measured from the 3D models created. The ratios (in percentage) of the measurements of each vertebra (except the sacral ones) forming the vertebral column region (cervical part, thoracic part, lumbar part) were determined for statistical analysis. We detected significant differences (P < 0.05) between sexes in all vertebrae forming the vertebral column of the chinchilla with respect to volume, surface area and vertebral body length, except for C6 and L1. This study is the first to carry out 3D reconstructions of data obtained from CT images in the chinchilla and the obtained results contribute to a more detailed understanding of the anatomy of this species. Our strategy may also be useful for the design of experiments exploring the vertebral column in domestic mammals and humans.


Robotica ◽  
2015 ◽  
Vol 34 (11) ◽  
pp. 2467-2485 ◽  
Author(s):  
Wen-ao Cao ◽  
Huafeng Ding ◽  
Ziming Chen ◽  
Shipei Zhao

SUMMARYThis paper presents a systematic method for dealing with mobility analysis and structural synthesis of a class of important spatial mechanisms with coupling chains, which involve more complex coupling relations than spatial parallel mechanisms. First, an approach to the establishment of the motion screw equation of the class of mechanisms is derived. Then, a general methodology for mobility analysis along with detection of rigid substructures is proposed based on the motion screw equation. Third, the principle of structural synthesis of the class of mechanisms is established on the basis of the method of mobility analysis. Finally, some novel spatial mechanisms with coupling chains are synthesized, illustrating the effectiveness of the method. The study of the paper will benefit structural analysis and synthesis of more complex spatial mechanisms with coupling chains.


2014 ◽  
Vol 1036 ◽  
pp. 1037-1040
Author(s):  
Radu Emanuil Petruse ◽  
Ioan Bondrea ◽  
Marco Sacco ◽  
Stefano Mottura

The purpose of the article is to introduce possibilities of using Augmented Reality instructions in order to better understand technical drawings. The aim of these instructions based on 3D models is to create AR training applications and analyze their impact on the users. These instructions consist in a 3D model, superimposed over the technical drawing. The AR application also offers step by step instructions for 3D modelling in CAD software, which are very useful in creating the 3D model starting from a technical drawing. The AR application was tested by students from the Faculty of Engineering in Sibiu, obtaining great improvements in their 3D modelling times. The results of a survey that the students completed reveal that the AR modelling instructions also aids their spatial visualization capability.


2017 ◽  
Vol 21 (1) ◽  
pp. 32-43 ◽  
Author(s):  
Nemanja Majstorović ◽  
Luka Čerče ◽  
Davorin Kramar ◽  
Mirko Soković ◽  
Branislav Glišić ◽  
...  

Summary Background: 3D modelling in orthodontics is becoming an increasingly widespread technique in practice. One of the significant questions already being asked is related to determining the precision of the scanner used for generating surfaces on a 3D model of the jaw. Materials and methods: This research was conducted by generating a set of identical 3D models on Atos optical 3D scanner and Lazak Scan laboratory scanner, which precision was established by measuring a set of orthodontic parameters (54 overall) in all three orthodontic planes. In this manner we explored their precision in space, since they are used for generating spatial models – 3D jaws. Results: There were significant differences between parameters scanned with Atos and Lazak Scan. The smallest difference was 0.017 mm, and the biggest 1.109 mm. Conclusion: This research reveals that both scanners (Atos and Lazak Scan), which belong to general purpose scanners, based on precision parameters can be used in orthodontics. Early analyses indicate that the reference scanner in terms of precision is Atos.


2021 ◽  
Vol 343 ◽  
pp. 04009
Author(s):  
Nicolae Florin Cofaru ◽  
Andrei Horia Brănescu ◽  
Vesna Marjanovic ◽  
Mirko Blagojevic ◽  
Vlăduţ Mihuţ

Within this paper, a detailed study is elaborated regarding the human foot during both orthostatic and gait, the main goal being to develop 3D models which are very useful in the foot motion and loading state research. In order to elaborate the accurate 3D modelling of the human foot assembly, a thorough biomechanical study is done. Such a study was required due to the fact of the high anatomical complexity of the motions within the foot, taking into consideration the 26 bones and 33 joints consisting it. The research aims the CAD modelling of the biomechanics of the healthy subjects alongside with predisposed pathological conditions. The resulting models will have important utility in both educational field and for further CAE approaches and studies.


Author(s):  
R. Ravanelli ◽  
L. Lastilla ◽  
M. Crespi

The aim of this work is to present a comparison among three software applications currently available for the Occipital Structure Sensor<sup>TM</sup>; all these software were developed for collecting 3D models of objects easily and in real-time with this structured light range camera. The SKANECT, itSeez3D and Scanner applications were thus tested: a DUPLO<sup>TM</sup> bricks construction was scanned with the three applications and the obtained models were compared to the model virtually generated with a standard CAD software, which served as reference.<br><br> The results demonstrate that all the software applications are generally characterized by the same level of geometric accuracy, which amounts to very few millimetres. However, the itSeez3D software, which requires a payment of $7 to export each model, represents surely the best solution, both from the point of view of the geometric accuracy and, mostly, at the level of the color restitution. On the other hand, Scanner, which is a free software, presents an accuracy comparable to that of itSeez3D. At the same time, though, the colors are often smoothed and not perfectly overlapped to the corresponding part of the model. Lastly, SKANECT is the software that generates the highest number of points, but it has also some issues with the rendering of the colors.


ACTA IMEKO ◽  
2017 ◽  
Vol 6 (3) ◽  
pp. 29 ◽  
Author(s):  
Piercarlo Dondi ◽  
Luca Lombardi ◽  
Marco Malagodi ◽  
Maurizio Licchelli

Measuring historical violins provides crucial information about the morphology of the instruments, useful both for researchers and violin makers. Generally, these measures are taken manually using a calliper, but they can be repeated only occasionally due to both the restricted access to these precious instruments and the need of avoiding accidental damages to the wood or to the varnishes. In this work, we describe and assess the accuracy of a protocol for the acquisition and creation of high quality 3D models of violins, suitable for taking accurate measurements. Six historical violins of 17th – 18th centuries, kept in “Museo del Violino” in Cremona (Italy), were used as test set. The quality of the final outcomes was checked comparing measures taken on the 3D meshes with the correspondent ones taken by calliper on the original instruments. Finally, a comparison between the sound board of the instruments were performed.


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