Virtual Manufacturing

COLLOQUIUM
VIRTUAL MANUFACTURING
By
ANURAG CHAUDHARY
(Registration No – 2015PR02)
M.Tech. III Semester (PP RR OO DD UU CC TT II OO NN EE NN GG II NN EE EE RR II NN GG )
Under The Guidance
Of
Dr. Audhesh Narayan
Master of Technology (M.Tech.)
in
PRODUCTION ENGINEERING
Submitted to the
DEPARTMENT OF MECHANICAL ENGINEERING
Motilal Nehru National Institute of Technology Allahabad
Allahabad, UP, India, 211004
September 26, 2016

Virtual Manufacturing
i
ACKNOWLEDGEMENTS
It is a great pleasure to express my sincere gratitude and profound regards to Dr. Audhesh Narayan,
Assistant Professor, Mechanical Engineering Department, MNNIT Allahabad, for his constant
encouragement, valuable guidance and help during the entire course of the work. Words are insufficient to
acknowledge the keen interest taken by him in all aspects of the present work.
I would also like to acknowledge the useful resources of the MNNIT Central Library.
Date:
Anurag Chaudhary
(Reg. No.- 2015PR02)

ii
ABSTRACT
Virtual Manufacturing system is a computer system which can generate the same
information about manufacturing system„s structure, states and behaviours as we
can observe in real manufacturing systems. Virtual reality and virtual
manufacturing often concentrate on an interface between VR technology and
manufacturing and production theory and practice. In terms of manufacturing
education, virtual concept is expected to be more safety, relevant and cost effective
than physical one. It is our belief that the direction of evolution of manufacturing
theory and practice will become clearer in the future once the role of VR
technology is understood better in developing this interface.
This report describes the Virtual Manufacturing System a virtual world consisting
of a machine shop in which engineering components can be made. The mechanisms
and processes of their manufacture are recorded so that those mechanisms and
processes can be carried out subsequently on real computer-numerically-controlled
machine tools.

iii
CONTENT
I. ACKNOWLEDGEMENTS i
II. ABSTRACT ii
III. LIST OF TABLES iv
IV. LIST OF FIGURES iv
1. INTRODUCTION 1
2.
HISTORY OF VIRTUAL MANUFACTURING AND VIRTUAL
REALITY
2-4
3. VIRTUAL REALITY TECHNOLOGIES 5-7
4. VIRTUAL MAUFACTURING 8-16
5.
METHODS AND SIMULATION TOOLS USED IN VIRTUAL
MANUFACTURING SYSTEMS
17
6.
EDUCATIONAL REQUIREMENTS FOR VIRTUAL
18-19
7. ECONOMICS AND SOCIO-ECONOMICS 20-23
8. ADEQUACY OF A VIRTUAL MANUFACTURING SYSTEM 24
9. APPLICATIONS OF VM 25-28
10. FUTURE RESEARCH DIRECTION 29
11. CONCLUSION 30
12. REFERENCES 31-32

iv
LIST OF TABLES:
Table I: Overview of Simulation Tools 17
Table II: Factors of Virtual Manufacturing 20
LIST OF FIGURES:
Figure 1: Virtual Manufacturing 10
Figure 2: Virtual Manufacturing Objectives, Scope And Domains 11
Figure 3: Role of Virtual Manufacturing System 18
Figure 4: Academic Research Versus Industrial Tools 22

1
CHAPTER-1
INTRODUCTION
The natural instinct of an engineer who wants to make a new device is to go to a
workshop, find some scrap aluminium or mild steel, and to machine up what is
required. The engineer will do this by eye where dimensions are not critical, and by
measurement where they are. He or she will make mistakes of course - holes may be
drilled in the wrong place initially or, more seriously, material may be cut which is
subsequently needed to support some other part of the component. But eventually a
rough hack at a prototype will emerge[1]
.
The idea of our Virtual Manufacturing System is to allow de signers to follow that
instinct, but with the added luxury of cost-free second thoughts. The system is a
virtual world representing a machine shop in which engineering components can be
made and, almost as importantly, unmade. This is to say that time can be reversed
to obliterate mistakes, material reappearing to fill erroneous cavities unlike the way
it so inconveniently doesn't in real life. Many people have produced simulation
systems that will replay a pre-determined sequence of machining operations inside
a computer, but we are not aware of any fully-interactive system that is intended to
be a source of such operations, and which is intended to be used by designers as a
design system[2]
.
The main aim of this report is briefly but completely describe the main features of
the virtual reality technology systems and describe new view to this area - Virtual
Manufacturing. Virtual Manufacturing use of a virtual reality systems for the CAD
of components and processes for manufacturing - for viewing 3D engineering
models to be passed to NC machines for real manufacturing. a lot of tasks in
manufacturing systems have been transferred from workshops into computer
systems and large parts of activities are considered to be carried out as information
processing within computers. For example, drafting papers and pens had been
replaced with CAD (computer aided design) system. Up-to late 1970s, NC part
programming performed at operating panel of NC controllers had been mainly
substituted by CAM (computer aided manufacturing) software nowadays. Virtual
Reality is technology for presentation of complicated information, manipulations
and interactions of person with them by computer. Method of dialogue of person
with computer is named interface and virtual reality is newest of row this
interfaces.

2
CHAPTER-2
HISTORY OF VIRTUAL MANUFACTURING AND VIRTUAL
REALITY
The most advanced current form of the Computer Aided Manufacturing is Virtual
Manufacturing (VM) based on Virtual Reality (VR). The concept of Artificial
Reality appeared already in the 1970s (Miron KRUEGER) and the notion of Virtual
Reality was introduced by Jaron Lanier (1989). In 1990 the concepts of Virtual
World and Virtual Environments appeared. Virtual reality is defined as a computer
generated interactive and immersive 3D environment simulating reality.
Let us have a short glimpse at the last three decades of research in virtual reality
and its highlights[3]
:
 Sensorama - in years 1960-1962 Morton Heilig created a multi-sensory simulator.
A prerecorded film in color and stereo, was augmented by binaural sound, scent,
wind and vibration experiences. This was the first approach to create a virtual
reality system and it had all the features of such an environment, but it was not
interactive.
 The Ultimate Display – in 1965 Ivan Sutherland proposed the ultimate solution of
virtual reality: an artificial world construction concept that included interactive
graphics, force-feedback, sound, smell and taste.
 “The Sword of Damocles” - the first virtual reality system realized in hardware,
not in concept. Ivan Sutherland constructs a device considered as the first Head
Mounted display (HMD), with appropriate head tracking. It supported a stereo view
that was updated correctly according to the user‟s head position and orie ntation.
 GROPE - the first prototype of a force-feedback system realized at the University
of North Carolina (UNC) in 1971.
 VIDEOPLACE - Artificial Reality created in 1975 by Myron Krueger - “a
conceptual environment, with no existence”. In this system the silhouettes of the
users grabbed by the cameras were projected on a large screen. The participants
were able to interact one with the other thanks to the image processing techniques
that determined their positions in 2D screen‟s space.
 VCASS - Thomas Furness at the US Air Force‟s Armstrong Medical Research
Laboratories developed in 1982 the Visually Coupled Airborne Systems Simulator –
an advanced flight simulator. The fighter pilot wore a HMD that augmented the out-

3
the window view by the graphics describing targeting or optimal flight path
information.
 VIVED - Virtual Visual Environment Display – constructed at the NASA Ames in
1984 with off-the-shelf technology a stereoscopic monochrome HMD.
 VPL - the VPL company manufactures the popular Data- Glove (1985) and the Eye
phone HMD (1988) - the first commercially available VR devices.
 BOOM - commercialized in 1989 by the Fake Space Labs. BOOM is a small box
containing two CRT monitors that can be viewed through the eye holes. The user
can grab the box, keep it by the eyes and move through the virtual world, as the
mechanical arm measures the position and orientation of the box.
 UNC Walkthrough project - in the second half of 1980s at the University of North
Carolina an architectural walkthrough application was developed. Several VR
devices were constructed to improve the quality of this system like: HMDs, optical
trackers and the Pixel-Plane graphics engine.
 Virtual Wind Tunnel - developed in early 1990s at the NASA Ames application
that allowed the observation and investigation of flow-fields with the help of
BOOM and Data Glove.
 CAVE - presented in 1992 CAVE (CAVE Automatic Virtual Environment) is a
virtual reality and scientific visualization system. Instead of using a HMD it
projects stereoscopic images on the walls of room (user must wear LCD shutter
glasses). This approach assures superior quality and resolution of viewed images,
and wider field of view in comparison to HMD based systems.
 Augmented Reality (AR) - a technology that “presents a virtual world that enriches,
rather than replaces the real world”. This is achieved by means of see-through HMD
that superimposes virtual three-dimensional objects on real ones. This technology
was previously used to enrich fighter pilot‟s view with additional flight information
(VCASS). Thanks to its great potential – the enhancement of human vision –
augmented reality became a focus of many research projects in early 1990s.
The term Virtual Manufacturing first came into prominence in the early 1990s, in
part as a result of the U.S. Department of Defense Virtual Manufacturing Initiative.
Both the concept and the term have now gained wide international acceptance and
have somewhat broadened in scope. For the first half of the 1990s, pioneering work
in this field has been done by a handful of major organizations, mainly in the
aerospace, earthmoving equipment, and automobile industries, plus a few

4
specialized academic research groups. Recently accelerating worldwide market
interest has become evident, fueled by price and performance improvements in the
hardware and software technologies required and by increased awareness of the
huge potential of virtual manufacturing. Virtual manufacturing can be considered
one of the enabling technologies for the rapidly developing info rmation technology
infrastructure.
VR representation techniques are widely used which means that they develop
rapidly. In product manufacturing techniques and organization, virtual reality has
become the basis of virtual manufacturing aimed at meeting the expectations of the
users/buyers of products, also as to their low cost and lead time. Virtual
manufacturing includes the fast improvement of manufacturing processes without
drawing on the machines' operating time fund. It is said that Virtual Manufacturing
is the use of a desktop virtual reality system for the computer-aided design of
components and processes for manufacture[4]
.

5
CHAPTER-3
VIRTUAL REALITY TECHNOLOGIES
Virtual Reality is technology for presentation of complicated information,
manipulations and interactions of person with them by computer. Method of
dialogue of person with computer is named interface and virtual reality is newest of
row this interfaces. After applications of virtual reality in area of computer games
are rise need to exercise these technologies in industry. Main areas of using of
virtual projecting and prototyping are automotive and air industry in this time.
Virtual projecting as very perspective method must by using in area of projecting of
manufacturing systems, too.
Historically, virtual reality has entered into the public awareness as medial toy with
equipment "helmet-glove", which was preferentially determined for wide public and
the price of this system had also to correspond to this fact, so price could not be
very high. As follows, the producers of virtual reality systems have aimed at
developing and providing of the systems for data collecting and analyzing and
systems supporting economic modelling. It is obvious that, from among areas,
where virtual reality systems can be most frequently used are applications based on
3D-space analyzing and physical dimension visualization. Virtual reality with
ability to show data 3D and attach sounds and touch information increases
extraordinarily data comprehensibility. Along with increasing the number of data
are increased the effects from virtual reality too[5]
.
After the first applications of Virtual reality (VR) in the field of flight simulators
and computer game creating, arisen the need to implement the virtual technologies
into industry. Product design and virtual prototyping is one of the greatest
successes of VR applications in industry. The main attention in the field of VR
system applications in the technical practice is given to CAD/CAM/CAE systems of
higher level. It is for the cause of realization of export in format VRML (Virtual
Reality Modelling Language). The newest versions of these systems could aid both
existing formats VRML 1.0 and VRML 2.0 (97). The cost of a VR system is very
specific problem. The real cost of an effective system can only be assessed in
relation to the benefits it brings to a company. Such hardware and software is so
expensive that only large corporations could afford to build virtual environments.
One of the possible ways to solve the problem is to implement a VR format to a

6
lower systems with aim actively utilize systems of Computer Integrated
Manufacturing.
VR systems could be divided by ways of communication with user to such groups:
1. Window on World Systems - for displaying the virtual world are used
conventional computer monitors. This system is also called Desktop Virtual
Reality, but usually it is called as Window on World (WoW).
2. Video Mapping - This system is modification of WoW system, where the siluetes
of human body could be displayed in 2D. User could see themselves on monitors in
interaction with environment.
3. Immersive Systems - basic VR systems, which enables user to be in virtual
environment. The feeling to be in is created by Head Mounted Displays (HMD).
This HMD could be with or without limitation of moving.
4. Telepresence - Attached to a high - speed network, VR takes telepresence to next
level. Participants can be thousands of kilometers apart and yet feel as if they are
all standing in the same virtual office or laboratory, with their product, design, or
experiment right in front of them not only talking about it, but interacting with it,
change it etc.
Distribution of VR systems by hardware equipment is in these levels. Some levels
are not strictly kept, mainly in VR systems of higher levels[6]
.
For a long time people have been gathering a great amount of various data. The
management of megabytes or even gigabytes of information is no easy task. In
order to make the full use of it, special visualization techniques were developed.
Their goal is to make the data perceptible and easily accessible for humans.
Desktop computers equipped with visualization packages and simple interface
devices are far from being an optimal solution for data presentation and
manipulation. Virtual reality promises a more intuitive way of interaction.
The first attempts to apply VR as a visualization tool were architectural
walkthrough systems. The pioneering works in this field were done at the
University of North Carolina beginning after year 1986, with the new system
generations developed constantly. Many other research groups created impressive
applications as well - just to mention the visualization of St. Peter Basilica at the
Vatican presented at the Virtual Reality World‟95 congress in Stuttgart or
commercial Virtual Kitchen design tool. What is so fantastic about VR to make it
superior to a standard computer graphics? The feeling of presence and the sense of

7
space in a virtual building, which cannot be reached even by the most realistic still
pictures or animations. One can watch it and perceive it under different lighting
conditions just like real facilities. One can even walk through non-existent houses -
the destroyed ones.
Another discipline where VR is also very useful is scientific visualization. The
navigation through the huge amount of data visualized in three-dimensional space is
almost as easy as walking. An impressive example of such an application is the
Virtual Wind Tunnel, developed at the NASA Ames Research Center. Using this
program the scientists have the possibility to use a data glove to input and
manipulate the streams of virtual smoke in the airflow around a digital model of an
airplane or space-shuttle. Moving around (using a BOOM display technology) they
can watch and analyze the dynamic behavior of airflow and easily find the areas of
instability. The advantages of such a visualization system are convincing - it is
clear that using this technology, the design process of complicated shapes of e.g.,
an aircraft, does not require the building of expensive wooden models any more. It
makes the design phase much shorter and cheaper. The success of NASA Ames
encouraged the other companies to build similar installations - at Eurographics‟95
Volkswagen in cooperation with the German Fraunhofer Institute presented a
prototype of a virtual wind tunnel for exploration of airflow around car bodies.
Other disciplines of scientific visualization that have also profited of virtual reality
include visualization of chemical molecules , the digital terrain data of Mars
surface etc.
Virtual engineering is currently approached in various ways. Because virtual
engineering is an emerging technology, its terminology and definition are not
completely established. In manufacturing, the major component of virtual
engineering is virtual manufacturing.

8
CHAPTER-4
VIRTUAL MAUFACTURING
Virtual manufacturing is defined as an integrated, synthetic manufacturing
environment exercised to enhance all levels of decision and control. It can be
categorized into three groups according to the
A. TYPE OF PRODUCT AND PROCESS DESIGN[8]
a) Design-centered VM: provides manufacturing information to the designer during
the design phase. In this case VM is the use of manufacturing-based simulations to
optimize the design of product and processes for a specific manufacturing goal
(DFA, quality, flexibility, …) or the use of simulations of processes to evaluate
many production scenario at many levels of fidelity and scope to inform design and
production decisions.
b) Production-centered VM: uses the simulation capability to modelize
manufacturing processes with the purpose of allowing inexpensive, fast evaluation
of many processing alternatives. From this point of view VM is the production
based converse of Integrated Product Process Development (IPPD) which optimizes
manufacturing processes and adds analytical production simulation to other
integration and analysis technologies to allow high confidence validation of new
processes and paradigms.
c) Control-centered VM: is the addition of simulations to control models and actual
processes allowing for seamless simulation for optimization during the actual
production cycle.
B. TYPE OF SYSTEM INTEGRATION According to the definitions proposed by
Onosato and Iwata[9]
, every manufacturing system can be decomposed into two
different sub-systems:
a) Real Physical System (RPS): An RPS is composed of substantial entities such
as materials, parts and machines that exist in the real world.
b) Real Informational System (RIS): An RIS involves the activities of information
processing and decision making.
c) Virtual Physical System (VPS): A computer system that simulates the responses
of a real physical system is a virtual physical system, which can be represented by
a factory model, product model, and a production process model. The production
process models are used to determine the interactions between the factory model
and each of the product models.

9
d) Virtual Information System (VIS): A computer system that simulates a RIS and
generates control commands for the RPS is called a „virtual informational system
(VIS).
C. TYPE OF FUNCTIONAL USAGE VM is used in the interactive simulation of
various manufacturing processes such as virtual prototyping, virtual machining,
virtual inspection, virtual assembly and virtual operational system.
 Virtual Prototyping (VP) mainly deals with the processes, tooling, and equipment
such as injection molding processes[10]
. VM is allied to the Virtual Prototyping, the
Virtual CAD and Virtual CAM made most of the time by simulation. Roger W Pryor
discussed in his paper on the potential real benefits that can be realized through
cost saving, minimization of number of prototype models.
 Virtual machining mainly deals with cutting processes such as turning, milling,
drilling and grinding, etc. The VM technology is used to study the factors affecting
the quality, machining time and costs based on modeling and simulation of the
material removal process as well as the relative motion between the tool and the
work piece.
 Virtual inspection makes use of the VM technology to model and simulate the
inspection process, and the physical and mechanical properties of the inspection
equipment.
 In Virtual Assembly, VM is mainly used to investigate the assembly processes, the
mechanical and physical characteristics of the equipment and tooling, the
interrelationship among different parts and the factors affecting the quality based
on modeling and simulation.
 A virtual assembly environment would enable a user to evaluate parts that are
designed to fit together with other parts. Issues such as handling ease of assembly
and order of assembly can be studied with virtual assembly.
 Virtual operational control makes use of VM technology to investigate the material
flow and information flow as well as the factors affecting the operation of a
manufacturing system.
We can also classify virtual engineering in terms of production life cycle as virtual
design, digital simulation, virtual prototyping, and virtual factory. Virtual design is
done on virtual reality equipment. Digital simulation permits the verification and
validation of the product's operation without using physical prototypes. Virtual
prototyping builds a simulated prototype that possesses the same geometry and

10
physical behavior as the real product. Virtual factory is a simulation of factory
production line.
There are many definition of Virtual Manufacturing (VM). Iwata (1993) defines
VM as follows: "A virtual manufacturing system is a computer system which can
generate the same information about a manufacturing system's structure, states and
behaviours as we can observe in real manufacturing systems".
The report from the 1994 Virtual Manufacturing User Workshop includes an in-
depth analysis of VM and its definition: "Virtual Manufacturing is an integrated
synthetic manufacturing environment exercised to enhance all levels of decision
and control" was annotated extensively to cover all the current functional and
business aspects of manufacturing. Also the practical side of manufacturing
virtuality is highlighted in this useful analysis. A comprehensive and thorough
survey of literature on VM problems relating to production design and control can
be found in a study done at the University of Maryland[11,12]
.
Figure 1: Virtual Manufacturing
 Environment: supports the construction, provides tools, models, equipment,
methodologies and organizational principles,
 Exercising: constructing and executing specific manufacturing simulations using
the environment which can be composed of real and simulated objects, activities
and processes,
 Enhance: increase the value, accuracy, validity,
 Levels: from product concept to disposal, from factory equipment to the enterprise
and beyond, from material transformation to knowledge transformation,

11
 Decision: understand the impact of change (visualize, organize, identify
alternatives)
The definition of VM given by a Bath University project team deserves attention.
According to this definition: "Virtual Manufacturing is the use of a desk-top virtual
reality system for the computer aided design of components and processes for
manufacturing - for creating viewing three dimensional engineering models to be
passed to numerically controlled machines for real manufacturing". This definition
emphasizes the functions aiding the machining process.
We choose to define the objectives, scope and the domains concerned by the Virtual
Manufacturing thanks to the 3D matrix represented in Fig. 2 which has been
proposed by IWB, Munich[12]
.
Figure 2: Virtual Manufacturing Objectives, Scope And Domains
The vertical plans represent the three main aspects of manufacturing today:
Logistics, Productions and Assembly, which cover all aspects directly related to the
manufacturing of industrial goods. The horizontal planes represent the different
levels within the factory. At the lowest level (microscopic level), VM has to deal
with unit operations, which include the behavior and properties of material, the
models of machine tool – cutting tool – work piece-fixture system. These models
are then encapsulated to become VM cells inheriting the characteristics of the lower
level plus some extra characteristics from new objects such as a virtual robot.
Finally, the macroscopic level (factory level) is derived from all relevant sub -
systems. The last axis deals with the methods we can use to achieve VM systems.

12
It is unquestionable that virtual manufacturing aids real manufacturing processes
and systems and it is perfected as the information technologies, the manufacturing
systems and the business demands develop. In this context, Virtual Manufacturing
should be recognized as an advanced information structure of Real Manufacturing
Systems, which integrates the available information tools and the virtual
environment immersiveness to achieve business-manufacturing goals.
Virtual manufacturing is used loosely in a number of contexts. It refers broadly to
the modelling of manufacturing systems and components with effective use of
audiovisual and/or other sensory features to simulate or design alternatives for an
actual manufacturing environment, mainly through effective use of computers. The
motivation is to enhance our ability to predict potential problems and inefficiencies
in product functionality and manufacturability before real manufacturing occurs.
Another term that is sometimes mentioned in the context of virtual manufacturing is
agile manufacturing - sometimes defined as a structure within which agility is
achieved through the integration of three primary resources: organization, people,
and technologies. A way to achieve this is through innovative management
structures and organization, a skill base of knowledgeable and empowered people,
and flexible and intelligent technologies. Whereas agility focuses on the ability to
make rapid changes in products and processes based on the voice of the customer,
virtual manufacturing provides a means for doing so. One area in which virtual
manufacturing has made an impact is that of rapid prototyping machines, building
prototypes by precise deposition of layer upon layer of powdered metal, a process
known as stereo lithography. Virtual reality (VR) has been used by companies such
as General Motors and Caterpillar to build electronic prototypes of vehicles,
instead of physical prototypes. This process reduces product development time
significantly.
The combination of information technology (IT) and production technology has
greatly changed traditional manufacturing industries. Many manufacturing tasks
have been carried out as information processing within computers. For example,
mechanical engineers can design and evaluate a new part in a 3D CAD system
without constructing a real prototype. As many activities in manufacturing systems
can be carried out using computer systems, the concept of virtual manufacturing
(VM) has now evolved.

13
VM is defined as an integrated synthetic manufacturing environment for enhancing
all levels of decision and control in a manufacturing system. VM is the integration
of VR and manufacturing technologies. The scope of VM can range from an
integration of the design sub-functions (such as drafting, finite element analysis
and prototyping) to the complete functions within a manufacturing enterprise, such
as planning, operations and control.
However, a practical VM system is highly multidisciplinary in nature. Many of
these research projects and commercial software for VM systems have restrictions
in their implementation. Firstly, many machining theories and heuristics need to be
modeled in a VM system. However, most VM applications are designed only for
specific problems in pre-defined conditions. There is no one VM application having
all the technologies necessary to model a real machining process. Secondly, each
constructing process of a new VM system is akin to the reinvention of "wheels".
Besides geometrical modelling of machines, analytical modelling of machining
parameters, such as the cutting force, also has to be developed for every specific
task. Lastly, various VM systems are developed with different programming and
modelling languages, making them less flexible and scalable due to incompatibility
problems. Any change m one part would require the whole system to be modified.
During a VM simulation process, 3D graphics or VR will be an enabling tool to
improve human-to-human or human-to-machine communications. VM addresses the
collaboration and integration among distributed entities involved in the entire
production process. However, VM is regarded as evolutionary rather than
revolutionary. It employs computer simulation, which is not a new field, to model
products and their fabrication processes, and aims to improve the decision-making
processes along the entire production cycle. Networked VR plays an essential role
in VM development.
Current VR and Web technologies have provided the feasibility to implement VM
systems. However, this is not an easy task due to the following factors:
 The conflicting requirements of real-time machining and rendering. Generally, a
high level of detail for a scene description would result in a high complexity of the
virtual scene.
 The conflicting requirements of static data structure and dynamic modelling. In the
virtual machining environment, a dynamically modeled work piece is essential.

14
 The requirements for a consistent environment to avoid confusion and provide
navigational cues to prevent a user from getting lost in the VR environment.
 The importance of an adequate sense of immersion in the VR environment, without
which even a highly detailed rendering will not help a user interact effectively in
the virtual 3D environment using conventional 2D interfaces such as a keyboard.
Representative applications of virtual reality technology are presented in a number
of areas. Applications in manufacturing or pointers to it have been emphasized
particularly. Immersive display technology can be used for creating virtual
prototypes of products and processes. The user can then be exposed to an
environment that is next best only to an actual product or process. Examples from
the product standpoint include virtual prototyping of a product, such as
earthmoving equipment, instead of expensive physical prototyping. From the
process standpoint, such examples include detailed layout design involving hard-to
quantify factors such as adequate illumination, sources of distractions for operators
caused by heavy goods, and personnel movement.
The issues here are concerned with CAD model portability among systems, trade-
offs between highly-detailed models and real-time interaction and display, rapid
prototyping, collaborative design using VR over distance, use of the World Wide
Web for virtual manufacturing in small and medium-sized business, using
qualitative information (illumination, sound levels, ease of supervision, handicap
accessibility) to design manufacturing systems, use of intelligent and autonomous
agents in virtual environments, and determining the validity of VR versus reality
(quantitative testing of virtual versus real assemblies/equipment).
A number of initiatives in this area have been undertaken at the National Institute
of Standards and Technology (MIST). Engineering tool kit environments are needed
that integrate clusters of functions that manufacturing engineers need in order to
perform related sets of tasks. Integrated production system engineering
environments would provide functions to specify, design, engineer, simulate,
analyze, and evaluate a production system. Some examples of the functions that
might be included in an integrated production system engineering environment
are[7]
:
 Identification of product specifications and production system requirements,
 Productibility analysis for individual products,
 Modelling and specification of manufacturing processes,

15
 Measurement and analysis of process capabilities,
 Modification of product designs to address manufacturability issues,
 Plant layout and facilities planning,
 Simulation and analysis of system performance,
 Consideration of various economic/cost trade-offs of different manufacturing
processes, systems, tools, and materials,
 Analysis supporting selection of systems/vendors,
 Procurement of manufacturing equipment and support systems,
 Specification of interfaces and the integration of information systems,
 Task and workplace design,
 Management, scheduling, and tracking of projects.
The interoperability of the commercial engineering tools that are available today is
extremely limited, so as users move back and forth between different software
applications carrying out the engineering process, (hey must reenter data. Examples
of production systems that may eventually be engineered using this type of
integrated environment include transfer lines, group technology cells, automated or
manually operated workstation's, customized multipurpose equipment, and entire
plants.
Manufacturers and their worldwide subcontractors and main suppliers can establish
agile manufacturing teams that will work together on the design, virtual
prototyping, and simulated assembly of a particular product while establishing
confidence in the virtual supply chain. Using the most advanced VR systems,
geographically remote members of the team can meet together in the same virtual
design environment to discuss and implement changes to virtual prototypes.
Examples of recent developments in virtual collaborative environments include
projection of gestures and movements of multiple remote designers as voice-
activated avatars to help explain the intention of the designer to others in real time
using high-speed ATM networks.
For monitoring and control of complex manufacturing systems, four dimensions can
be conceived to express complexity[6]
:
1. Space permits us to examine the physical location, layout, and flow issues
critical in all manufacturing operations.
2. Time permits us to address facility life-cycle and operational dynamic issues,
beginning with concurrent engineering of the production process and testing

16
facilities during product design, extending through production and decline of the
initial generation product(s), cycling through the same process for future-
generation products.
3. Process allows us to study the coherent integration of engineering, management,
and manufacturing processes, it permits examination of the important, yet intricate
interplay of relationships between classically isolated functions. As examples,
consider relationships between production planning and purchasing, production
control and marketing, quality and maintenance, and design and manufacturing.
Processes involve decisions ranging from long-range operational planning to
machine/device-level short-term planning and control. The integration between
various levels of aggregation is essential.
4. Network deals with organization and infrastructure integration. Whereas the third
dimension focuses on the actions, this dimension concentrates on the actors and
their needs and responsibilities. Clearly including personnel, the set of actors also
includes ail devices, equipment, and workstations; all organizational units, be they
cells, teams, departments, or factories; and all external interactors, such as
customers, vendors, subcontractors, and partners. Issues such as contrasting
hierarchically controlled networks with hierarchical, autonomous agent networks
must be addressed.
Virtual manufacturing techniques enhance our ability to understand the four
dimensions described above by addressing issues such as designing products that
can be evaluated and tested for structural properties, ergonomic Functionality, and
reliability, without having to build actual scale models; designing products for
aesthetic value, meeting individual customer preferences; ensuring Facility and
equipment compliance with various Federally mandated standards, Facilitating
remote operation and control of equipment (telemanufacturing and telerobotics);
developing processes to ensure manufacturability without having to manufacture
the product (e.g. avoiding destructive testing); developing production plans and
schedules and simulating their correctness; and educating employees on advanced
manufacturing techniques, worldwide, with emphasis on safety[5]
.

17
CHAPTER-5
METHODS AND SIMULATION TOOLS USED IN VIRTUAL
VM has two main core activities. The first one is the “Modeling Activity” which
determines what to model and degree of thought that is needed. The second on is
the “Simulation Activity” which represents model in a computer based environment
and compare to the response of the real system with degree of accuracy and
precision[11]
.
The following methods are necessary to achieve VM system:
Manufacturing characterization confines measure and analyze the variables that
influence material transformation during manufacturing. Modeling and
representation technologies provide different kinds of models for representation,
standardization the processes in such a way that the information can be shared
between all software applications (Knowledge based systems, Object oriented,
feature based models). Visualization, environment construction technologies
includes Virtual reality techniques, augmented reality technology, graphical user
interfaces for representation of information to the user in a meaningful manner and
easily comprehensible. Verification, validation and measurement the tools and
methodologies needed to support the verification and validation of a virtual
manufacturing system. Multidiscipline optimization: VM and simulation are usually
no self-standing research disciplines, they often are used in combination with
“traditional” manufacturing research. Nowadays numerous tools are available for
simulating manufacturing levels. Table[12]
shows the overview of simulation tools
applicable in manufacturing process.
Table I: Overview of Simulation Tools

18
CHAPTER-6
EDUCATIONAL REQUIREMENTS FOR VIRTUAL
Figure 3: Role of Virtual Manufacturing System
Old-fashioned manufacturing systems without virtual concept have processed
material and data by user operation and physical facilities. Nowadays, however,
manufacturing systems consist of two parts: one is a physical system, the other is a
virtual one. Since virtual systems are constructed and operated in the computer
systems, the virtual can be more safety and more cost-effectively. And after the
verification of the data in the virtual environment, the error-free data transmitted
into the physical environment. There for the relationship between the physical and
virtual manufacturing systems can be collaborative.
To obtain the maximized effectiveness of the virtual manufacturing system, there
are some essential requirements.
 3 D visualization
Since almost all manufacturing facilities such as an NC machine, a robot
manipulator and a work table, have 3 dimensional shape, showing the 3 D geometric
information can achieve the insight reasoning of the object‟s status. For interactive
and dynamic visualization, the recommended features are:

19
 zoom in/out, zoom certain region,
 rotating, panning
 perspective and orthogonal projection
 Identical Man-Machine Interface
To train the facility operation, user interfaces of virtual simulator are required
identical with the real physical facilities. The enumerated virtual facility interfaces
are:
 control panels and teach pendant with push button, rotate switch, jogging tool
 screens showing status
 Simulation
Based-on 3 D geometric model, the systems are required to support the following
items:
 discrete-event simulation handling with user-inputs as well as system-generated
events
 detection of collision
 estimation of cycle time
 Interface and monitoring
 CAD interface for input model construction
 generation of next-step data such as an NC code or a robot program file
 transmission of information into the real manufacturing system
 teacher‟s monitoring of student‟s practice status

20
CHAPTER-7
ECONOMICS AND SOCIO-ECONOMICS
Table II: Factors of Virtual Manufacturing
EXPECTED BENEFITS
As small modifications in manufacturing can have important effects in terms of cost
and quality, Virtual Manufacturing will provide manufacturers with the confidence
of knowing that they can deliver quality products to market on time and within the
initial budget. The expected benefits of VM are:
 From the product point of view it will reduce time-to-market, reduce the number of
physical prototype models, improve quality, …: in the design phase, VM adds
manufacturing information in order to allow simulation of many manufacturing
alternatives: one can optimize the design of product and processes for a specific
goal (assembly, lean operations, …) or evaluate many production scenarios at
different levels of fidelity,
 From the production point of view it will reduce material waste, reduce cost of
tooling, improve the confidence in the process, lower manufacturing cost,…: in the
production phase, VM optimizes manufacturing processes including the physics
level and can add analytical production simulation to other integration and analysis
technologies to allow high confidence validation of new processes or paradigms. In
terms of control, VM can simulate the behavior of themachine tool including the

21
tool and part interaction (geometric and physical analysis), the NC controller
(motion analysis, look-ahead)…
If we consider flow simulation, object-oriented discrete events simulations allow to
efficiently model, experiment and analyze facility layout and process flow. They
are an aid for the determination of optimal layout and the optimization of
production lines in order to accommodate different order sizes and product mixes.
The existence of graphical-3D kinematics simulation are used for the design,
evaluation and off-line programming of work-cells with the simulation of true
controller of robot and allows mixed environment composed of virtual and real
machines.
The finite element analysis tool is widespread and as a powerful engineering desig n
tool it enables companies to simulate all kind of fabrication and to test them in a
realistic manner. In combination with optimization tool, it can be used for decision-
making. It allows reducing the number of prototypes as virtual prototype as cheaper
than building physical models. It reduces the cost of tooling and improves the
quality, …
VM and simulation change the procedure of product and process development.
Prototyping will change to virtual prototyping so that the first real prototype will
be nearly ready for production. This is intended to reduce time and cost for any
industrial product. Virtual manufacturing will contribute to the following
benefits[11]
:
1. Quality: Design For Manufacturing and higher quality of the tools and work
instructions available to support production;
2. Shorter cycle time: increase the ability to go directly into production without
false starts;
3. Producibility: Optimize the design of the manufacturing system in coordination
with the product design; first article production that is trouble-free, high quality,
involves no reworks and meets requirements.
4. Flexibility: Execute product changeovers rapidly, mix production of different
products, return to producing previously shelved products;
5. Responsiveness: respond to customer “what-ifs” about the impact of various
funding profiles and delivery schedule with improved accuracy and timeless,
6. Customer relations: improved relations through the increased participation of
the customer in the Integrated Product Process Development process.

22
ECONOMIC ASPECTS
It is important to understand the difference between academic research and
industrial tools in term of economic aspects.
Figure 4: Academic Research Versus Industrial Tools
The shape of the face in the diagram presented in Figure[12]
, is defined by two
curves:
– “effort against level of detail” where “level of detail” refers to the accuracy of
the model of simulation (the number of elements in the mesh of a FEM model or the
fact if only static forces are taken into account for a simulation , …
– “effort against development in time” is a type of time axis and refers to future
progress and technological developments (e.g. more powerful computers or
improved VR equipment).
Universities develop new technologies focusing on technology itself. Researchers
do not care how long the simulation will need to calculate the results and they not
only develop the simulation but they need to develop the tools and methods to
evaluate wether the simulation is working fine and wether the results are exact. On
the other hand, industrial users focus on reliability of the technology, maturity
economic aspects (referring to the effort axis) and on the integration of these
techniques within existing information technology systems of the companies (e.g.
existing CAD-CAM systems, …). To our mind, Virtual Manufacturing is, for a part
of its scope, still an academic topic. But in the future, it will become easier to use
these technologies and it will move in the area of industrial application and then

23
investments will pay off. For example in the automotive and aerospace companies
in the late 60‟s, CAD was struggling for acceptance. Now 3 -D geometry is the basis
of the design process. It took 35 years for CAD-CAM to evolve from a novel
approach used by pioneers to an established way of doing things. During this
period, hardware, software, operating systems have evolved as well as education
and organizations within the enterprise in order to support these new tools. Today,
some techniques are daily used in industry, some are mature but their uses are not
widespread and some are still under development.

24
CHAPTER-8
ADEQUACY OF A VIRTUAL MANUFACTURING SYSTEM
It will depend on the adequacy of the model that how much the virtual system is
close to the real system. The adequacy of a virtual manufacturing system is defined
as the agreed degree of accuracy and precision between the responds of the VMS
and the real system under the same conditions in all points of the modeling space.
Two problems arise here, how accurate and how precise the virtual model is.
Accuracy determines the deviation of the results produced by VMS from the
results, produced by the real system.
Precision defines the spread of modeling results. There is a curious detail here: the
problem is how to increase the spread of simulation results rather than to reduce it.
VMS often exhibits a "perfectly precise" behavior, yielding repetitive constant
responses at a point of the modeling space, something which is quite far from the
real situation. To implant a stochastic character to the VMS, methods of the
imitation modeling are employed in which the principal factors are modeled as
stochastic to emulate a stochastic system behavior.
The process of proving the adequacy of a VMS is called validation. If the VMS
does not represent adequately the real system, it should be improved iteratively
until the desired degree of accuracy and precision is achieved. Th is process is
referred to as a calibration.

25
CHAPTER-9
APPLICATIONS OF VM
The virtual manufacturing has been successfully applied to many fields such as,
automobile manufacturing, aeronautics and astronautics, railway locomotives,
communication, education and so on, which has an overpowering influence on
industrial circles.
A. Automotive domain[13]
The Integrated-Computer Aided Research on Virtual
Engineering Design and Prototyping Lab of Wisconsin University developed a set
of virtual foundry platform which make use of solid glasses to observe three-
dimensional image, establish multifarious geometric model by language and ma ke
sure geometry size and place with data glove. American Daimler Chrysler
Automotive Company adopted virtual prototype technology in their research of
automobile part and thus shortened the developing period. American Caterpillar
Co., the world‟s leading manufacturer of engineering machinery and construction
equipment, applied virtual prototype technology in the design optimization and the
internal visibility evaluation of loaders. The shape design using the virtual
technology can be modified and evaluated at any time. The modeling data after
scheme confirming can be directly used for the stamping tool design, simulation
and processing, even for the marketing and propaganda. Application of V M is used
in automobile factory shop floor and also in car driving simulation. Song Cheng
describes a case research of D auto-company‟s virtual paint shop established with
the technology of three dimensional simulations.
B. Aerospace domain Virtual Manufacturing in aerospace industry is used in FEA
to design and optimize parts, e.g. reduce the weight of frames by integral
construction, in 3D-kinematics simulation to program automatic riveting machines,
and few works dealing with augmented reality and virtual reality to support
complex assembly and service tasks in aircraft design[12]
. The aero engine model
created in virtual environment describes where tools are developed and used to help
manufacturing and design engineers to take action and decisions on problems
normally solved only by experience. Henrik R[14]
explained application of VM in
aircraft domain by considering Turbine Exhaust Casing (TEC). TEC is
manufactured by fabrication and about 200 welds are needed to manufacture the
product. Issues have been identified with the robustness of the geometrical
tolerances created during production. Several welding sequence concepts were

26
investigated to find a more robust manufacturing sequence. From the welding
simulations it was shown that the residual stresses could be lowered using a
different welding sequence. Moreover, to further avoid the issue with geometrical
tolerances a pre-deformation was given to the product before welding, the amount
of needed pre deformation was calculated by the virtual welding simulation tool.
C. Healthcare domain Healthcare is one of the biggest adopters of virtual reality
which encompasses surgery simulation, phobia treatment, robotic surgery and skills
training[15]
. One of the advantages of this technology is that it allows healthcare
professionals to learn new skills as well as refreshing existing ones in a safe
environment. Plus it allows this without causing any danger to the patients. Virtual
manufacturing applications in the healthcare industry are associated with many
leading areas of medical technology innovation including robot -assisted surgery,
augmented reality (AR) surgery, computer-assisted surgery (CAS), image-guided
surgery (IGS), surgical navigation, multi-modality image fusion, medical imaging
3D reconstruction, pre-operative surgical planning, virtual colonoscopy, virtual
surgical simulation, virtual reality exposure therapy (VRET), and VR physical
rehabilitation and motor skills training. Stent design influences the post-procedural
hemodynamic and solid mechanical environment of the stented artery by
introducing non-physiologic flow patterns and elevated vessel strain. This
alteration in the mechanical environment is known to be an important factor in the
long-term performance of stented vessels. Because of their critical function, stent
design is validated by methods such as FEA.
D. Home Appliance domain The virtual kitchen equipment system developed by a
Japanese company Matsushita allows customers to experience functions of a variety
of equipment in virtual kitchen environment before the purchase of actual
equipment. These choosing results can be stored and send to the production
department through computer network and be manufactured.
E Other applications of VM explicated[16]
Product shape style designs of
conventional automobiles adopt the plastic to manufacture the shape model. The
shape design using the virtual technology can be modified and evaluated at any
time. In the shape design of other products such as building and decoration,
cosmetic packing, communication, etc. has great advantages. In piping system
design, through the implementation of virtual technology, the designer can enter
into virtual assembly by conducting piping layout and check the potential

27
interference and other problems. Product movement and dynamics simulation
displays the product behavior and dynamically perform the product performance.
The product design must solve the movement coordination and cooperation of each
link on the production line. The usage of simulation technology can intuitively
conduct the configuration and design, and guarantee the working coordination. In
Product assembly simulation the coordination and assembly property of mechanical
product is the place where most errors of the designers emerge. In the past, the
error at final stage leads to the scrapping of parts and delay manufacture product
which causes more economic losses and damage. The implementation of virtual
assembly technology can conduct the verification in the stage of design, and ensure
the correctness of design to avoid the loss. The adoption of virtual reality
technology in virtual prototype suitably helps in 3D modeling of products, and then
set the model into VE to control, simulate and analyze. Simulation and optimization
of the productive process of enterprise are used in the productive technology by
formulating the products, man power of the factory, reasonable allocation of
manufacturing resources, material storage and transportation system. LIU Qing-ling
addressed the VM system provides the working environment of collaboration for the
virtual enterprise partners, that affords collaboration support for each link of the
whole course of orders of users, originality in product, design, production of parts,
set assembling, sales and after sale services. Virtual Simulation is an important
technologic method accounting for complex design and testing of designing
proposal. Yongkang Ma explains in his research that the elements such as welding
robots and fixtures of workstation for body-in-white welding are analysed and
optimized using digital modelling method of work station.
F. Virtual Teaching Platform of Digital Design and Manufacturing To promote
students‟ learning interest and improve teaching effects Jianping Liu and Qing
Yang adopts a virtual teaching platform of digital design and manufacturing in
innovation teaching methodology. Yu Zhang explains virtual reality technology in
program -based learning helps students to establish their spatial concepts and
enhance their understanding on engineering drawings. Huang Xin represents motion
simulation of entire product mechanisms could be achieved by means of the
function of intelligent simulation. Liu Jianping suggests that with the help of the
CAD software, students can easily understand how to read technical drawing and
replicate same in software, and the cost of design can also be saved.

28
G. Virtual Training Hazim El-Mounayri concluded that the architecture of a virtual
training environment (VTE) was used to develop the corresponding system for the
case of CNC milling. A recent application of VE based training includes training
for operation of engineering facilities, CNC manufacturing. The Learning
Environments Agent (LEA) engine includes a hierarchical process knowledge base
engine, an unstructured knowledge base engine for lecture delivery; a rule based
expert system for natural-language understanding, and an interface for driving
human-like virtual characters. Integrated Virtual Reality Environment for Synthesis
and Simulation engine was used to drive the virtual environment, display the
engineering facility and manage a multimodal input from a variety of sources. A
general geometric modeling approach is based on modeling precisely the geometries
involved in the machining operation, including work-piece geometry and tool
geometry.
H. The Development Of Virtual Manufacturing Mold On Automobile Panels The
development process of mould virtual manufacturing. At first, the desired
production is analysized, and then concept design is performed. After that, the
optimized design and system integration can be performed. In a virtual
environment, the virtual product model can be constructed by using relevant
software[17]
. This is a gradual process. According to the product development
requirement, virtual model function, the behavior of simulation model and
performance of the virtual simulation analysis are compelled by adopting
corresponding simulation analysis tools. Then modeling and simulation analysis are
repeated which bases on the results of the simulation analysis. When the
improvement and model of virtual manufacturing mold meet the original design
objective, then the real manufacturing is expected to start before the automobile
panels being put on production, all the production has gone through the inspection
of virtual practice. Thus the potential difficulties of production and unreasonable
design can be removed through the virtual analysis. Then all the design c an be
modified or redesigned until the entire manufacturing process can be reasonably
and smoothly finished. Therefore it can not only shorten the period of development
cycle and reduce the cost of development, but also can improve the quality of
products.

29
CHAPTER-10
FUTURE RESEARCH DIRECTION
The research on virtual manufacturing technology is still at the stage of system
framework and general technology, while the application oriented research on the
key technology needs to be developed. The future research directions are as
follows:
 VP technology and system of assembly simulation, production process,
scheduling simulation and NC machining process simulation should be based
on photorealistic animation.
 Man-machine cooperation solution in virtual environment and virtual
manufacturing with the virtual reality technology.
 The distributed/collaborative simulation technology of the hybrid model
based on complex system.
 Requirements of a large amount of CPU power for real-time simulation.
 Open system architecture for virtual manufacturing research based on the
distributed processing environments.
 Selective addition to animation
 Shop floor based generic models
 VM methodology for process characterization
 Technologies to simulate assembly operations
 Declarative representation of product and processes
 Natural language for VM meta-model
 Cost database and integration
 VM user interface (communication between VM knowledge base and user)
 VM verification & validation methods, algorithms & tools
 Process model and simulation validation
 Methodology for using a VM system
 VM framework (guidelines, integration standards, etc.)
 Methodology for design abstraction
 Tools to relate conceptual design with possible manufacturing methods and
processes and cost estimates based on manufacturing features
 Manufacturing engineering automation (knowledge-based computer
applications to perform manufacturing engineering decision making)
 Simulation architecture

30
CHAPTER-11
CONCLUSION
The term global virtual manufacturing (GVM) extends the definition of VM to
include, and emphasize, the use of Internet/intranet global communications
networks for virtual component sourcing, and multisite multiorganization virtual
collaborative design and testing environments. Companies that commit to GVM may
be able to dramatically shorten the time to market for new products, cut the cost of
prototyping and preproduction engineering, enable many more variations to be tried
out before committing to manufacture, and Increase the range and effectiveness of
quality assurance testing. Virtual prototypes can be virtually assembled, tested, and
inspected as part of production planning and operative graining procedures; They
can be demonstrated, market tested, used to brief and rain sales and customer staff,
transmitted instantly from site to site via communications links, and modified and
recycled rapidly in response to feedback.
Designers do not design in real time but manufacturing does occur in real time. It is
therefore necessary for a design by manufacture system to be able to relax and
tighten the applied constraints as required by the designer. Additionally, multiple
levels of constraints may be applied in different circumstances; for example there
are several possible ways of dealing with feed rates:
 no constraint (pure design, don't care about feed rates);
 feedback constraint (design with manufacturing in mind) use colour, sound, and
labels to indicate physical quantities such as rate of metal removal;
 full constraint (manufacturing conditions) don't allow constraints to be broken.
For the flexibility and performance we require, be believe that a constraint system
based on rules, rather than physical modelling, will best meet our needs.
Virtual reality and virtual manufacturing often concentrate on an interface between
VR technology and manufacturing and production theory and practice. In this report
we concentrate on the role of VR technology in developing this interface. It is our
belief that the direction of evolution of manufacturing theory and practice will
become clearer in the future once the role of VR technology is understood better in
developing this interface.

31
CHAPTER-12
REFERENCES
1. G.M. Bayliss Real-time geometric modelling for manufacture University of Bath
School of Mechanical Engineering Technical Report 001/1994.
2. Bowyer The Svlis user manual University of Bath School of Mechanical
Engineering Technical Report 002/1994.
3. MARCINČIN, J. N.: Application of the Virtual Reality Technologies in Design of
Automated Workplaces. Transactions of the Universities of Košice, Vol. 10, No. 1,
Košice, 2001, pp. 47-51, ISSN 1335-2334.
4. BANERJEE, P., ZETU, D.: Virtual Manufacturing. John Wiley and Sons, New
York, 320 p., ISBN 0-471-35443-0.
5. LEDERER G.: Virtual Manufacturing - Manufacturers Challenge of the 1990s.
CIME - Computer Integrated Manufacture and Engineering. Vol. 1, No. 2, 1996, pp.
44-46.
6. NEAGA, I., KURIC, I.: Virtual Environments for Product Design and
Manufacturing. In: Proceedings „CA Systems and Technologies“. Zilina, 1999, pp.
60-65.
7. ONG, S. K., NEE, A. Y. C.: Virtual and Augmented Reality Applications in
Manufacturing. Springer-Verlag London, 387 pp., ISBN 1-85233-796-6.
8. Xi Junjie, Research on Virtual Manufacturing and System Structure of Complex
Products, 3rd International Conference on Information Management, Innovation
Management and Industrial Engineering, 2010.
9. Ka Iwata and Ma Onosato and Ka Teramoto and Sa A. Osaki, Modeling and
Simulation Architecture for Virtual Manufacturing System”, Annals CIRP, 44,pp.
399–402,1995.
10.G. Gary Wang, Definition and review of virtual protyping, Canada.
11.Saadoun M., Sandoval V., Virtual Manufacturing and its implication, Virtual reality
and Prototyping, Laval, France, 1999.
12.Dépincé Ph., Tracht K., Chablat D., Woelk P.-O., Future Trends of the Machine
Tool Industry, Technical Workshop on Virtual Manufacturing, October 2003,
EMO‟2003.
13.Er. Raj Kumar, An overview of virtual manufacturing with case studies, IJEST, Vol
3, Iss 4, 2011.

32
14.Henrik Runnemalm, Virtual Manufacturing of Light Weight Aero Engine
Components, ISABE, 2009.
15.Tomasz Mazuryk and Michael Gervautz, Virtual Reality: History, Applications,
Technology and Future.
16.Li Liu, Application Status and Development Trend of Virtual Manufacturing, IEEE,
2011.
17.X.Y.Ruan, Z.L.Lou, “Digital Plasticity Forming Technology And Science in 21
Century,” J. Die and Mould Technology. Shanghai, vol. 35, pp 3–8, February 2003.

Virtual Manufacturing

Recommandé

Recommandé

Contenu connexe

Tendances

Tendances (20)

Similaire à Virtual Manufacturing

Similaire à Virtual Manufacturing (20)

Dernier

Dernier (20)

Virtual Manufacturing