ΕΛΛΗΝΙΚΗ ΔΗΜΟΚΡΑΤΙΑ
Ανώτατο Εκπαιδευτικό Ίδρυμα Πειραιά
Τεχνολογικού Τομέα
Ορολογία στην Ξένη Γλώσσα
Ενότητα: Flexible Manufacturing II
Παναγιώτης Τσατσαρός
Τμήμα Μηχ. Αυτοματισμού ΤΕ
Άδειες Χρήσης
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Το παρόν εκπαιδευτικό υλικό υπόκειται σε άδειες χρήσης Creative Commons.
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Για εκπαιδευτικό υλικό, όπως εικόνες, που υπόκειται σε άλλου τύπου άδειας
χρήσης, η άδεια χρήσης αναφέρεται ρητώς.
Χρηματοδότηση
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Το παρόν εκπαιδευτικό υλικό έχει αναπτυχθεί στα πλαίσια του εκπαιδευτικού
έργου του διδάσκοντα.
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Το έργο «Ανοικτά Ακαδημαϊκά Μαθήματα στο Ανώτατο Εκπαιδευτικό
Ίδρυμα Πειραιά Τεχνολογικού Τομέα» έχει χρηματοδοτήσει μόνο την
αναδιαμόρφωση του εκπαιδευτικού υλικού.
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Το έργο υλοποιείται στο πλαίσιο του Επιχειρησιακού Προγράμματος
«Εκπαίδευση και Δια Βίου Μάθηση» και συγχρηματοδοτείται από την
Ευρωπαϊκή Ένωση (Ευρωπαϊκό Κοινωνικό Ταμείο) και από εθνικούς πόρους.
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1.
Σκοποί ενότητας ................................................................................................ 4
2.
Περιεχόμενα ενότητας........................................................................................ 4
3.
Flexible Manufacturing II.................................................................................... 5
4.
3.1
The basics of flexible manufacturing ........................................................... 5
3.2
Part families ................................................................................................ 6
3.3
Flexible modules ......................................................................................... 6
3.4
Flexible cells. .............................................................................................. 6
3.5
Components of a system............................................................................. 7
3.6
Types of flexibility ........................................................................................ 7
3.7
Related automation systems. ...................................................................... 8
Computer Simulation ......................................................................................... 8
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1. Σκοποί ενότητας
The aims of this unit are to:
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Provide authentic text and vocabulary specific to the needs of students of
Automation Engineering
Encourage students to combine their knowledge of English with their
technical knowledge
Enable students to understand text coherence through the use of
conjunctions and linking words
Provide students with practice in context relevance
2. Περιεχόμενα ενότητας
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Flexible Manufacturing related to other disciplines
Flexible Manufacturing: principles, technology and components
Flexible Manufacturing Cells and Flexible Manufacturing Modules
Types of flexibility of Flexible Manufacturing Systems and Subsystems
Flexible Manufacturing Systems and related automation systems
Computer Simulation in Flexible Manufacturing Systems
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3. Flexible Manufacturing II
Related to—and sometimes synonymous with—agile manufacturing, adaptable
manufacturing, cellular manufacturing, computer-integrated manufacturing, flexible
machining, and flexible automation, flexible manufacturing encompasses a diverse
set of manufacturing principles and technologies with a few common goals:
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achieving a highly automated manufacturing process with rigorous
computerized monitoring and management of quality and productivity
making manufacturing operations readily scalable for different levels of output
allowing customization and reconfiguration of manufacturing processes with
minimal downtime and cost
providing management with detailed and timely information about the
manufacturing process
enabling manufacturers to coordinate their work processes with those of their
suppliers and customers to maximize efficiency and minimize costs
___________, flexible manufacturing systems (FMS) generally consist of a
combination of computerized numerical control (CNC) machines, robots, selfdiagnostic systems, and a hierarchical information system. They may___________
include any number of other devices for material handling and other functions. These
systems are designed to be easily reprogrammed or even regrouped with other
devices___________ permit rapid and inexpensive changes in the manufacturing
process, facilitating quick responses to market changes and allowing for so-called
mass customization of products. FMS can___________ monitor, schedule, and route
workflow to maximize efficiency and to avoid deadlocks ___________ component
failures or backlogs on certain devices.
3.1 The basics of flexible manufacturing
___________each FMS is unique in configuration and process, an abstract
description of overall operations in outline form is possible. ___________, numerical
control programs and computer-aided process planning are utilized to develop the
sequence of production steps for each machined part. ___________, based on
inventory, orders, and computer simulations of how an FMS can run most
economically, a schedule is established for parts that are going to be produced on
that day. ___________, material and required tooling arc retrieved either
automatically or manually from storage and loaded into the system. ___________
loaded, the FMS begins machining operations. ___________the process plan,
robots, conveyors, and other automated material handling devices transport the
workpiece between workstations. Should any tool break down during the production
cycle, an FMS can reroute the workpiece to other tools within the system.
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3.2 Part families
Most FMS (or their subsystems) are designed to produce any number of related
workpieces. ___________, the essential characteristics that constitute a workable
"partfamily" are common shape, size, weight and tolerance range. ___________
members of a part family share many traits, usually a software-directed change is all
an FMS requires to switch from producing one kind of part to another.
3.3 Flexible modules
Workstations, or individual processing units, are a concept central to any discussion
of FMS. A processing unit refers to the sum of operations performed within a
particular factory area containing several pieces of process equipment meant to carry
out individual or multiple operations on various products. ___________, different
workstation distinctions mark the divide between two FMS subsystems—the flexible
manufacturing module (FMM) and the flexible manufacturing cell (FMC). The module
comprises a stand-alone numerically controlled machine tool (NCMT), automatic
material handling device (such as a robot or automatic pallet changer) and an
automated monitoring system to control for tool breakage, equipment depreciation,
automatic measuring and related diagnostics. FMM constitute the first step in the
automation of the loading and unloading of parts to and from an NCMT. For
machining centers, automatic pallet changers make it possible for unmanned
attended machining to occur for___________ six hours.
3.4 Flexible cells.
The flexible manufacturing cell, ___________, comprises two or more machine tools
which may or may not include NCMT. ___________ FMM. the FMC incorporates a
material handling device (such as a robot) servicing several machine tools arranged
in a circle or line. Automatic pallet changers are also used___________ automatic
conveyor systems linking NCMT. ___________ an FMM, information flow to and
from an FMC is integrated into a larger monitoring control system. FMC are less
flexible than FMM. Usually FMC are applied to a "family," ___________some
broader grouping of components----___________shafts within a prescribed size
range. ___________each FMC is designed to meet the specialized requirements of
different customers, standardization is not a universal feature. ___________, just the
design phase requires considerable consultation and information exchange between
the specific user and FMC supplier. It should be noted that early versions of FMC
and FMS initially functioned below their anticipated performance level. Problems
arose ___________the technical difficulties involved when linking product flows with
different machines. ___________, demand for FMC is initially limited to a few large
firms with enough financial clout to undertake the risky investment the systems
represented.
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3.5 Components of a system
With the above subsystems in mind. FMS can be distinguished by the following
characteristics: the flow of tools and parts between different machine groups is
automated; material handling is mostly, but not exclusively, performed by automated
guided vehicle systems (AGVS), and not, as ___________ FMC, industrial robots.
This is explained by the fact that FMS consist of machining centers mostly involved
with the production of, geometrically speaking, prismatic parts, while material
handling robots work___________ computer numerically controlled (CNC) lathes that
machine rotational parts. ___________ FMS also incorporate the use of conveyors
and rail guided transport systems. And, ___________ their subsystems, FMS have a
lower rate of labor utilization, higher labor productivity, and, ___________ higher
capital productivity. FMS are usually equipped with a "hot standby" feature. This
alludes to a computer control system comprising two computer units. Should one fail
to operate, the other automatically kicks in to keep the FMS running.
3.6 Types of flexibility
__________ joint characteristics, FMS and their subsystems share most, if not all, of
the following to differing degrees:
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Machine flexibility—the ease of making the changes necessary to
manufacture a specific set of part/product types.
Process flexibility—the capacity to manufacture a given set of part/product
types in a variety of ways, each possibly using different materials.
Product flexibility—the systematically unique condition to change over to
produce a new set of parts or products economically and quickly.
Routing flexibility—the capability to cope with breakdowns and continue
manufacturing a given set of part/product types using alternative routes.
Volume flexibility—the ability to operate profitably across a range of different
production volumes.
Expansion flexibility—the potential to expand in a modular fashion.
Production flexibility—the variable domain of part/product types that a system
can produce.
__________ all flexible systems are not equally versatile__________, manufacturers
must determine which aspects of flexibility best serve business
objectives__________ cost efficiency, speed, or the ability to rapidly implement
product alterations. These objectives will dictate what kinds of tasks are best suited
for flexible solutions and how much capital should be invested to develop each
component of the FMS.
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3.7 Related automation systems.
__________ true FMS and their subsystems, are two other manufacturing concepts
distinguished by their comparatively higher level of automation and lower level of
flexibility. These are the flexible transfer line and fixed transfer line. Between these
two systems and FMS a trade-οff, or "productivity dilemma," is said to exist.
__________, the higher the level of automation, the greater the manufacturer
efficiency__________ productivity and lower unit costs.__________ the efficiency
advantage held by non-FMS related systems is said to be achieved__________
losing a certain degree of innovative flexibility.
The flexible transfer line comprises workstations utilizing numerous automated
general or special purpose machine tools joined by an automated workpiece flow
system __________ line principle. The flexible transfer line is capable of
simultaneously or sequentially machining different workpieces running along the
same path. A fixed transfer line, _________, utilizes a number of special purpose
machine tools ( __________ general ones) initially designed to produce one product
only. After a considerable period of setup time __________, it can accommodate a
different variant of the product, as in the case of different sized cylinder heads.
Fill in the blanks above with the words given below. Some of the words must be used
more than one times.
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According to (x2) / in comparison with / for instance
Once / in general / such as
As opposed to (x2) / next / in all respects
Although / because / since (x2)
Up to / in certain cases / similar to
As a result / more specifically / indeed
In terms of (x2) / to a far greater extent / accordingly
In conjunction with(x2) / on the other hand / while
Compared to / likewise / in order to
Besides / due to (x2) / first
In the case of / at the expense of / by contrast
Though / following that / but
In fact / also
4. Computer Simulation
One of the __________ features of FMS is computer simulation. Thirty years after
their introduction, a _________ of microcomputer-based simulation packages are
available for simulation analysis. There are also many mainframe simulation
packages now available in a microcomputer format. __________ their mainframe
forerunners, microcomputer simulation packages are considered user-friendly and do
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not require the __________ of highly skilled individuals. __________ developments
introduced sophisticated color graphics in conjunction with several __________ in
computer mainframes that allowed software developers to create even more complex
programs that their user-friendly orientation. A __________ advance is the
incorporation of animation techniques. In the opinion of Nigel Greenwood, had
simulation analysis been available in the early days of FMS. their success
__________ would have been greatly enhanced.
Computer simulation exercises are performed to identify system __________ the
utilization of fixed resources such as machine tools and variable resources such as
operators, tools, and material __________. Utilization of resources is measured in
terms of busy, idle, down, and __________ time. Simulation results then provide
information to FMS designers about work in progress, production rates, and the
__________ of equipment failure, all __________factors that determine how well a
particular FMS works. When computer simulation packages first appeared, many
experienced production engineers __________ their usefulness. Having been
schooled in a "hard modeling" simulation background that used scale __________,
pieces of paper, drawing pins, and the like to represent personnel and pallets,
experienced engineers were skeptical of computer simulation modeling. The
substantial advantages of computer simulation and the __________ of new
engineers with computer trained backgrounds has __________ this initial skepticism.
One critical limitation of computer simulation is that computer simulation modelers
are unable to accurately __________ a specifically designed FMS facility, so that the
possibility of an informational __________ between FMS project designers and
simulators exists. Heightened communications between these two groups ensures
that discrepancies arc minimized. It is also expected that __________ developments
in microcomputer-based packages will help minimize discrepancies.
In the evolution of an FMS during its multiphase design process, computer simulation
is of great assistance. During the __________ design phase, if given a hypothetical
array of workstation configurations, a computer simulation is able to determine their
__________ throughput times to a high degree of reliability. It is also used to
calculate initial financial analysis and to animate __________ configurations. During
the detailed design phase, computer simulation makes it possible for suggested
system improvements to be incorporated and tested in an FMS model to analyze
their impact.
Fill in the blanks with the words given below
impact / respective / transporters / unlike / layout / conceptual presence / prospective
/ questioned / outstanding / alleviated bottlenecks / further / depict / blocked /
advances / note-worthy plethora / retain / rate / relevant / discrepancy / influx
subsequent
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