scholarly journals POSSIBILITIES OF THE APPLICATION OF THREE-DIMENSIONAL TECHNOLOGIES AND MODERN TECHNOLOGICAL MEANS IN THE CRIME INVESTIGATION ACTIVITY

2018 ◽  
Vol 18 ◽  
pp. 98-105
Author(s):  
N. V. Pavliuk
Keyword(s):  
Digital Media ◽  
Technology Use ◽  
Laser Scanning ◽  
3D Model ◽  
Imaging System ◽  
3D Visualization ◽  
Three Dimensional ◽  
Scanning System ◽  
Crime Reconstruction ◽  
Technological Means

The issues related to the introduction of innovative methods, technologies and technological means in the investigation of crimes are considered. It is noted that one of the main directions of the development of Criminalistics is the assimilation of the virtual reality associated with computerization of spheres of life, implementation of modern technologies and their use in law enforcement. Technology use of laser scanning of terrain and objects resulting in 3D model is produced allows several times to increase informative value of data collected at the incident scene, provides a visual and convenient visualization in three-dimensional form. As against photo and video images, 3D model has a stereoscopic image and the ability to freely change the angle while viewing. Besides to scanning results can be stored on any digital media without the possibility of changes or adjustments. Attention is focused on the technological capabilities of 3D-visualization systems on examples of their use in foreign countries as technological means of capturing the situation of the scene and the subsequent of a crime reconstruction. Thus, using a portable three-dimensional imaging system for working with volumetric traces at a crime scene, it is possible to obtain accurate three-dimensional images of traces of protectors or footprints (shoes) on soil and snow. This system is an alternative to traditional methods of fixing evidence: photofixing and making plaster casts. Unlike other systems, new approach does not require the use of lasers. The expediency of expanding the range of 3D laser scanning system use in modern investigative and judicial practice of our state with the aim of increasing the level of provision of pre-trial investigation authorities with technological means and bringing it closer to European standards is argued.

scholarly journals INTEGRATION OF SURVEYING TECHNIQUES TO DETECT THE IDEAL SHAPE OF A DOME: THE CASE OF THE ESCUELAS PÍAS CHURCH IN VALENCIA

2019 ◽  
Vol XLII-2/W9 ◽  
pp. 39-43
Author(s):  
S. Artese ◽  
J. L. Lerma ◽  
J. Aznar Molla ◽  
R. M. Sánchez ◽  
R. Zinno
Keyword(s):  
Laser Scanning ◽  
3D Model ◽  
Three Dimensional ◽  
Historical Building ◽  
Software Packages ◽  
Similarities And Differences ◽  
3D Documentation ◽  
Almost All ◽  
The Church ◽  
The Ideal

<p><strong>Abstract.</strong> The three-dimensional (3D) documentation and surveying of cultural heritage can be carried out following several geomatics techniques such as laser scanning and thermography in order to detect the original 3D shape after applying reverse engineering solutions. In almost all cases, the integration of data collected by different instruments is needed to achieve a successful and comprehensive 3D model of the as-built architectural shape of the historical building. This paper describes the operations carried out by the authors to determine the as-built 3D model of the Escuelas Pias Church, related namely to the dome and circular nave. After the description of the church and historical notes, attention will be driven to the indirect registration results obtained with three different laser scanning software packages, highlighting similarities and differences, and the consequences while generating meshes. The 3D model carried out will then be described and the results of some investigations with regard to the hypotheses about the design of the dome and the origin of the alterations will be presented.</p>

Recognition and repairing of surface hole in three dimensional laser scanning system

2016 ◽  
Vol 9 (1) ◽  
pp. 114-121
Author(s):  
吕源治 LYU Yuan-zhi ◽  
孙 强 SUN Qiang ◽  
毕国玲 BI Guo-ling
Keyword(s):  
Laser Scanning ◽  
Three Dimensional ◽  
Scanning System ◽  
Laser Scanning System

Effects of Combustion Chamber Geometry Upon Exit Temperature Profiles

2009 ◽  
Author(s):  
Clayton Kotzer ◽  
Marc LaViolette ◽  
William Allan
Keyword(s):  
Combustion Chamber ◽  
Laser Scanning ◽  
Reference Model ◽  
Ambient Pressure ◽  
Three Dimensional ◽  
Temperature Fields ◽  
Scanning System ◽  
Geometric Deviations ◽  
Exit Temperature ◽  
Engine Operating Condition

The purpose of this research was to investigate the effects of combustion chamber geometry on exit temperature fields using an ambient pressure test rig. The apparatus contained a 120° sector of a combustion section of a Rolls Royce (previously Allison) T56-A-15 gas turbine engine. A thermocouple rake acquired high-resolution temperature measurements in the combustion chamber exit plane. Rig test conditions were set to simulate an engine operating condition of 463 km/h (250 knots) at 7620 m (25000ft) by matching the Mach number, the equivalence ratio and the Sauter mean diameter of the fuel spray. To quantify the geometric deviations of the combustion chamber specimens, which varied in service conditions, a three-dimensional laser scanning system was used. Combustion chamber geometric deviations were extracted through comparison of the scanned data to a reference model using the selected software. The relationship between combustion chamber exit temperature profile and geometric deviation was then compared. The main conclusion of this research was that small deviations from nominal dimensions in the dilution zone of the combustion chamber correlated to an increase in pattern factor. A decrease in the mixing of the products of combustion and dilution air was observed as damage in the dilution zone increased. This reduction in mixing created a more compact, higher temperature core flow. The results obtained from this research were compared to past studies.

3D Laser Scanner and its Application in Engineering Survey

2013 ◽  
Vol 671-674 ◽  
pp. 2111-2114
Author(s):  
Yan Ping Feng ◽  
Wei Guo Li ◽  
Li Bing Yang ◽  
Yan Li Gao ◽  
Wen Bin Li
Keyword(s):  
Laser Scanning ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Laser Scanner ◽  
Target Object ◽  
Scanning System ◽  
3 Dimensional ◽  
Working Principle ◽  
Laser Scanning System ◽  
Three Dimensional Space

3D laser scanning system is to use laser ranging principle to record intensively the 3D coordinates, reflectivity and texture information on the surface of the target object. It makes a real record of the three-dimensional space, which makes traditional measurement be released from the limit that couldn’t be exceeded in the past, and let the measurement precision up to a new level. At the same time, it has provided extensive researches with better help than ever. This paper mainly discusses the characteristics, working principle, application and future development of the ground 3 dimensional laser scanner.

Three Dimensional Modeling of Buildings Using Three Dimensional Laser Scanning Data

2012 ◽  
Vol 594-597 ◽  
pp. 2398-2401
Author(s):  
Dong Ling Ma ◽  
Jian Cui ◽  
Fei Cai
Keyword(s):  
Point Cloud ◽  
Laser Scanning ◽  
3D Visualization ◽  
Cloud Model ◽  
Three Dimensional ◽  
3D Models ◽  
Three Dimensional Modeling ◽  
Dimensional Modeling ◽  
Feature Lines ◽  
Point Cloud Model

This paper provides a scheme to construct three dimensional (3D) model fast using laser scanning data. In the approach, firstly, laser point cloud are scanned from different scan positions and the point cloud coming from neighbor scan stations are spliced automatically to combine a uniform point cloud model, and then feature lines are extracted through the point cloud, and the framework of the building are extracted to generate 3D models. At last, a conclusion can be drawn that 3D visualization model can be generated quickly using 3D laser scanning technology. The experiment result shows that it will bring the application model and technical advantage which traditional mapping way can not have.

Complex 3D Measuring by Multiple Laser Scanning of Automotive Parts

2013 ◽  
Vol 837 ◽  
pp. 511-516
Author(s):  
Adrian Catalin Voicu ◽  
Gheorghe I. Gheorghe
Keyword(s):  
Reverse Engineering ◽  
Laser Scanning ◽  
Three Dimensional ◽  
Correct Choice ◽  
3D Scanning ◽  
Single Step ◽  
Graph Representation ◽  
Scanning System ◽  
Production Environment ◽  
Virtual Design

For over 20 years the term"three-dimensional scan"(3D) showed the world the possibilities of virtual design, simulation, or reverse engineering. 3D scanning is also known as 3D digitizing, the name coming from the fact that this is a process that uses a contact or non-contact digitizing probe to capture the objects form and recreate them in a virtual workspace through a very dense network of points (xyz) as a 3D graph representation. Until recently, digitization was limited by the speed of the scan head and the correct choice of the probing system, type of scanned piece and budget for the purchase or develops the scanning system. With the evolution of technology appeared a number of new techniques that tend to improve the properties of classical methods. Even if intended for copying or geometrical control, or rather virtual geometric modelling or product realization, there are two groups of technologies: with contact (classical methods with probes) or without contact (laser, optical or combination). Most automotive manufacturers currently use 3D scan metrology based on optical or laser systems to validate products quality. The pieces are initially measured by 3D scanning then they are compared with the designed model (CAD file) using a specialized software. By this comparison producer can interfere very quickly in the manufacturing process to remove the cause of defects, this technique being called Reverse Engineering (RE). There are many variables that affect accuracy of laser scanning and therefore the quality of information: reflectance of surface, colour object, recesses, openings narrow and sharp edges can be difficult to scan. This accuracy may vary from micron to millimetre and the acquisitions size from a few points to several thousand points per second. The overall accuracy of a 3D acquisition system depends above all on the sensors precision and on the acquisition device (acquisition with contact) or acquisition structure (acquisition without contact). In a perfect world or in an integrated production environment, 3D measuring systems should be able to measure all the necessary parameters in a single step without errors, and to render the results in the same way to the manufacturing networks equipped with computers, in formats useful for machines control and processes management.

Reverse Engineering Physical Models Employing Wrap-Around B-Spline Surfaces and Quadrics

1996 ◽  
Vol 210 (2) ◽  
pp. 147-157 ◽  
Author(s):  
D J Weir ◽  
M J Milroy ◽  
C Bradley ◽  
G W Vickers
Keyword(s):  
Reverse Engineering ◽  
Computer Aided Design ◽  
Laser Scanning ◽  
Three Dimensional ◽  
Surface Fitting ◽  
Physical Models ◽  
Scanning System ◽  
Cad Model ◽  
Three Dimensional Model ◽  
B Spline

Reverse engineering involves digitizing a three-dimensional model or part, by means of a tactile or non-contact optical sensor, converting the data to a CAD (computer aided design) database description and manufacturing by CNC (computer numerical controlled) machines. This paper demonstrates an effective approach to the reverse engineering of physical models by employing a three-dimensional laser scanning system in conjunction with surface-fitting software developed by the authors. Accurate surface data are collected by the laser scanner and then input to the surface-fitting software. Surface entities such as B-spline and quadric functions are employed to build the CAD model. The CAD model is compatible with popular design and manufacturing software packages. A telephone receiver is used to illustrate the efficiency of the process.

Research on 3D Reconstruction of the Facial Surface Reverse Engineering

2011 ◽  
Vol 201-203 ◽  
pp. 113-116 ◽  
Author(s):  
Jie Yang ◽  
Lei Zhao
Keyword(s):  
Computer Aided Design ◽  
Laser Scanning ◽  
Three Dimensional ◽  
Scanning System ◽  
3D Face Reconstruction ◽  
Surface Integration ◽  
Computer Aided ◽  
Point Data ◽  
Aided Design ◽  
Laser Scanning System

According to the surface integration of laser technology and computer-aided design and computer-aided manufacturing technology (CAD & CAM), a method that is rebuilt surface of three-dimensional facial reconstruction has been explored. A laser scanning system is used to collect the 3D discrete point data of the facial model, which will be cut up by their characteristics and curvature in order to make a 3D face reconstruction. The maximum reconstructive error is 0.2174mm. Application results indicate that the proposed method is quite satisfactory for facial reconstructive surgery, rehabilitation design and plastic surgery.

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