From Traditional to Virtual Design of Machine-Tools: A Long Way to Go ... Part 1 — Problem Identification and Model Validation

2006 ◽  
Author(s):  
Raffaele Bedini ◽  
Giovanni Tani ◽  
Alessandro Fortunato ◽  
Giovanni Gallorini ◽  
Claudio Mantega
Keyword(s):  
Model Validation ◽  
Machine Tools ◽  
Experimental Validation ◽  
Virtual Design ◽  
Problem Identification ◽  
Design Procedures ◽  
Traditional Design ◽  
Set Up

This paper reports the final results of research devoted to providing a package of tools for the Virtual Design of Machining Centers for an Italian manufacturer involved until today with traditional design procedures. The general thematics of Virtual Design have been realistically defined and focalised on the topics of particular interest for the firm; these constraints are analysed and the chosen solutions discussed. The paper also reports on the experimental validation of some complex parameters of the models of the Machining Centers already set up.

Application of Tree Graph Method for Reducing the Total Time of Tool Changing in Milling and Boring Machine Tools

2013 ◽  
Vol 371 ◽  
pp. 431-435 ◽  
Author(s):  
Claudiu Obreja ◽  
Gheorghe Stan ◽  
Lucian Adrian Mihaila ◽  
Marius Pascu
Keyword(s):  
Machine Tools ◽  
Design Method ◽  
Machining Process ◽  
Cnc Machine Tools ◽  
Tree Graph ◽  
Cnc Machine ◽  
High Productivity ◽  
Automatic Tool Changer ◽  
Automatic Tool ◽  
Set Up

With a view of increasing the productivity on CNC machine tools one of the main solution is to reduce, as much as possible, the auxiliary time consumed with the set-up and replacement of the tools and work pieces engaged in the machining process. Reducing the total time of the tool changing process by the automatic tool changer system can be also achieved through minimizing the number of movements needed for the actual exchange of the tool, from the tool magazine to the machine spindle (the optimization of the tool changing sequences). This paper presents a new design method based on the tree-graph theory. We consider an existing automatic tool changing system, mounted on the milling and boring machining centre, and by applying the new method we obtain all the possible configurations to minimize the tool changing sequence of the automatic tool changer system. By making use of the method proposed we obtain the tool changing sequences with minimum necessary movements needed to exchange the tool. Reconfiguring an existing machine tool provided with an automatic tool changer system by making use of the proposed method leads to obtaining the smallest changing time and thus high productivity.

POLICE IN FIGHT AGAINST ORGANISED CRIME — PROBLEM IDENTIFICATION

2021 ◽  
Vol 140 (4) ◽  
pp. 164-172
Author(s):  
AGNIESZKA ARAUCZ-BORUC
Keyword(s):  
Organised Crime ◽  
Central Bureau ◽  
Ordinary People ◽  
Problem Identification ◽  
Crime Problem ◽  
Cross Border ◽  
The World ◽  
Set Up

Organised crime, in view of its nature, is very dangerous, and its extensive structure not only in Poland, but all over the world causes a great threat to ordinary people. In Poland, the main service established to fight crime, including organised crime, is the police. The fight against organised crime (of an economic, drug, criminal, terrorism-related nature, including cross-border crime) is handled by the police organisational unit set up in 2000 - the Central Bureau of Investigation. The purpose of the article is to present the police as a competent service in the fi eld of recognising, combatting and preventing organised crime.

Differences and Dialogic Learning in a Collaborative Virtual Design Studio

2006 ◽  
Vol 31 (3) ◽  
pp. 85-94
Author(s):  
Jeffrey Hou ◽  
Min-Jay Kang
Keyword(s):  
Cultural Dimensions ◽  
Design Studio ◽  
Virtual Design ◽  
Dialogic Learning ◽  
Design Collaboration ◽  
Collaborative Environment ◽  
Traditional Design ◽  
The Social ◽  
Operational Issues

With the ability of linking distant partners and diverse bodies of students and faculty, virtual design studios provide unique opportunities for examining cultural, contextual, and methodological differences in design and design collaboration. However, most evaluations of virtual design studio in the recent literature have focused primarily on technical and operational issues. In contrast, the social and cultural dimensions of virtual design studio and their pedagogical implications have not been adequately examined. To address this gap, this article examines the experience and outcomes of a recent virtual design studio involving international collaboration between faculty and student partners. Specifically, it looks at how presence of differences and process of dialogic learning create pedagogical opportunities in a collaborative 'virtual' environment. Based on the case study, this article argues that through dialogues, collaboration, and negotiation of cultural, contextual and methodological differences, collaborative virtual design studio offers an alternative to traditional design studio based on the primacy of individual practice and the master-apprentice model of learning. By creatively utilizing the collaborative environment involving diverse partners, virtual design studio can foster a critical understanding of cross-cultural design process and the significance of dialogues and negotiation in design.

Realization of planar frequency selective fabrics and analysis of transmission characteristics

2016 ◽  
Vol 87 (11) ◽  
pp. 1360-1366 ◽  
Author(s):  
Fuwang Guan ◽  
Hong Xiao ◽  
Meiwu Shi ◽  
Weidong Yu ◽  
Fumei Wang
Keyword(s):  
Resonance Frequency ◽  
Transmission Curve ◽  
Experimental Transmission ◽  
Design Procedures ◽  
Traditional Design ◽  
Narrow Bandwidth ◽  
Simulation Calculation ◽  
Computer Based ◽  
Frequency Selective ◽  
Relevant Work

Based on traditional frequency selective surfaces (FSSs), the research ideas of novel frequency selective fabrics (FSFs) are proposed. In this paper, the specific square-loop patch FSF was chosen as an example to illustrate the design procedures, including ANSYS (HFSS) simulation and numerical calculation methods, and then a computer-based experiment was conducted to develop prototypes. Although the simulation, calculation, and experiment results have minor differences, especially the resonance frequency, they show good consistency overall, which demonstrates that traditional design methods could also apply to 2D FSFs. The experiment transmission curve shows obvious band-stop response, peaking at -37.12 dB at the resonance frequency 11.65 GHz, and the narrow bandwidth of -10 dB is predicted from 10.85 GHz to 12.55 GHz. To further verify the validity of design procedures, two complementary cross-shaped FSFs were fabricated through a computer embroidery process, and the experimental transmission curves are complementary as expected, peaking at -26.05 dB and 0 dB at the same resonance frequency 9.65 GHz, and the narrow bandwidths of -10 dB and -0.5 dB are 1.07 GHz and 0.41 GHz, respectively. Although many problems need to be solved in further research, this convenient fabrication method and theoretical basis could make relevant work feasible in later study.

From Traditional to Virtual Design of Machine-Tools: A Long Way to Go ... Part 2 — The Talk Between Two Worlds

2006 ◽  
Author(s):  
Raffaele Bedini ◽  
Giovanni Tani ◽  
Alessandro Fortunato ◽  
Gabriele Goti ◽  
Claudio Mantega
Keyword(s):  
High Speed ◽  
Experimental Tests ◽  
Design Environment ◽  
Virtual Design ◽  
Sensitive Data ◽  
Simulation Language ◽  
Input Module ◽  
Set Up ◽  
Microsoft Windows ◽  
Graphic Module

To allow easy and fast interaction between the simulation modules developed by the authors in a Virtual Design environment and the data bases set up in the past by an Italian manufacturer for the traditional design of Machining Centers for High Speed Milling, a graphic interface was created. The work was done utilising advanced features of Matlab suitable, through Microsoft Windows assisted procedures, to extract from Microsoft Excel sheets all sensitive data regarding the machine-tool components, feeding the input module of the simulation package. In this way it is now possible to perform intensive simulation campaigns quickly and easily avoiding the very burdensome procedures demanded for the input to the simulation language. This graphic module also makes it possible to quickly present and compare the results of experimental tests with the outputs of simulation runs.

scholarly journals Development and Validation of a Calibration Gauge for Length Measurement Systems

Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 3960 ◽  
Author(s):  
Francisco Javier Brosed ◽  
Raquel Acero Cacho ◽  
Sergio Aguado ◽  
Marta Herrer ◽  
Juan José Aguilar ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Machine Tools ◽  
Experimental Validation ◽  
Element Analysis ◽  
Measurement Systems ◽  
Guidance Systems ◽  
Verification Systems ◽  
Development And Validation

Due to accuracy requirements, robots and machine-tools need to be periodically verified and calibrated through associated verification systems that sometimes use extensible guidance systems. This work presents the development of a reference artefact to evaluate the performance characteristics of different extensible precision guidance systems applicable to robot and machine tool verification. To this end, we present the design, modeling, manufacture and experimental validation of a reference artefact to evaluate the behavior of these extensible guidance systems. The system should be compatible with customized designed guides, as well as with commercial and existing telescopic guidance systems. Different design proposals are evaluated with finite element analysis, and two final prototypes are experimentally tested assuring that the design performs the expected function. An estimation of the uncertainty of the reference artefact is evaluated with a Monte Carlo simulation.

scholarly journals A Cold-Pressing Method Combining Axial and Shear Flow of Powder Compaction to Produce High-Density Iron Parts

Technologies ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 70 ◽  
Author(s):  
Grigoriev ◽  
Dmitriev ◽  
Korobova ◽  
Fedorov
Keyword(s):  
Material Flow ◽  
Axial Loading ◽  
Powder Compaction ◽  
Friction Forces ◽  
Pressing Method ◽  
Cold Pressing ◽  
Traditional Design ◽  
Active Friction ◽  
Set Up ◽  
Active Friction Forces

Highly performance methods for cold pressing (cold die forging) of preforms from iron powder with subsequent heat treatment and producing ready parts made of powder are described in the paper. These methods allow fabricating parts with smooth surfaces and improved mechanical characteristics—porosity, tensile strength. Application of the traditional design set-up with a single-axial loading is restricted to high stresses in the dies to deform the preforms that lead to cracks formation. New powder compaction schemes by applying active friction forces (shear-enhanced compaction) make it possible to unload dies and produce high-quality parts by cold pressing. The scheme allows moving the die in the direction of the material flow with a velocity that exceeds the material flow velocity.

Generalized Kinematic Modeling of Reconfigurable Machine Tools

1998 ◽  
Vol 124 (1) ◽  
pp. 47-51 ◽  
Author(s):  
Yong-Mo Moon ◽  
Sridhar Kota
Keyword(s):  
Machine Tools ◽  
Screw Theory ◽  
Cost Effective ◽  
Mathematical Representation ◽  
Kinematic Modeling ◽  
Effective Manner ◽  
Systematic Selection ◽  
Motion Characteristics ◽  
Set Up ◽  
Representation Scheme

To accommodate frequent changes in product design and to be able to process a family of products in a timely and cost-effective manner, the next generation of machine tools should be reconfigurable. Reconfigurability enables reduction not only in machine design lead time but more significantly a reduction in machine set-up and ramp-up time. The essential characteristics of Reconfigurable Machine Tools (RMTs) include modularity, convertibility, flexibility, and cost-effectiveness. This paper presents a mathematical representation scheme using screw theory that lays the foundation for systematic design of reconfigurable machine tools. The motion characteristics of a set of desired machining tasks as well as stored library of machine modules are captured in a common representation scheme. A simple design example to illustrate the application of this methodology for systematic selection and synthesis of reconfigurable machine tools is presented.

Analysis of Position for the 4-PUU Parallel Manipulator

2012 ◽  
Vol 220-223 ◽  
pp. 1757-1760
Author(s):  
Shu Hua Sun
Keyword(s):  
Machine Tools ◽  
Parallel Manipulator ◽  
Three Dimensional ◽  
Parallel Robots ◽  
Industrial Robots ◽  
Rehabilitation Robot ◽  
Analytic Geometry ◽  
Forward Solution ◽  
Numerical Examples ◽  
Set Up

An original 4-PUU parallelManipulator with three-dimensional translations and one rotational motion about Z axis was presented. Its positional inverse modals were set up by using the conversion of coordinates and projection in analytic geometry, and the method of the forward solution of theManipulator and corresponding numerical examples were given.This methods were verified by using MATLAB software,which can provide the basis for studying the parallel robots work space. And it has wide application in the fields of industrial robots, micromanipulators, virtual axis machine tools, damping platform, rehabilitation robot and other fields.

SAFETY AND RELIABILITY OF BREAKWATERS

1984 ◽  
Vol 1 (19) ◽  
pp. 164 ◽  
Author(s):  
A. Mol ◽  
R.L. Groeneveld ◽  
A.J. Waanders
Keyword(s):  
Reliability Analysis ◽  
Probability Distributions ◽  
Simulation Method ◽  
Design Parameters ◽  
Suggested Approach ◽  
Design Procedures ◽  
Traditional Design ◽  
Safety And Reliability ◽  
Event Trees ◽  
Rubble Mound Breakwaters

This paper discusses the need to incorporate a reliability analysis in the design procedures for rubble mound breakwaters. Such an analysis is defined and a suggested approach is outlined. Failure mechanisms are analysed and categorized in Damage Event Trees. The probability of failure is computed using a level III simulation method to include time and cumulative effects and to account for skewed probability distributions. Typical outputs of the computer program are shown and compared with results according to traditional design approaches. The paper concludes that there is a definite need to include reliability analysis in the design procedures for larger breakwaters and such an analysis must consider the accuracy of design parameters and methods.

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