Computer-Aided Design, Engineering, & Manufacturing Systems Techniques & Applications, Computer-Int

297 Pages·2016·10.74 MB·English

COMPUTER-AIDED DESIGN,
ENGINEERING, AND MANUFACTURING
Systems Techniques And Applications
VOLUME
II
COMPUTER-
INTEGRATED
manufacturing
COMPUTER-AIDED DESIGN,
ENGINEERING, AND MANUFACTURING
Systems Techniques And Applications
V O LU M E
I I
COMPUTER-
INTEGRATED
manufacturing
Editor
CORNELIUS LEONDES
CRC Press
Boca Raton London New York Washington, D.C.
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Preface
A strong trend today is toward the fullest feasible integration of all elements of manufacturing including
maintenance, reliability, supportability, the competitive environment, and other areas. This trend toward
total integration is called concurrent engineering. Because of the central role information processing
technology plays in this, the computer has also been identified and treated as a central and most essential
issue. These are the issues which are at the core of the contents of this volume.
This set of volumes consists of seven distinctly titled and well-integrated volumes on the broadly
significant subject of computer-aided design, engineering, and manufacturing: systems techniques and
applications. It is appropriate to mention that each of the seven volumes can be utilized individually. In
any event, the great breadth of the field certainly suggests the requirement for seven distinctly titled and
well-integrated volumes for an adequately comprehensive treatment. The seven-volume titles are:
1. Systems Techniques and Computational Methods
2. Computer-Integrated Manufacturing
3. Operational Methods in Computer-Aided Design
4. Optimization Methods for Manufacturing
5. The Design of Manufacturing Systems
6. Manufacturing Systems Processes
7. Artificial Intelligence and Robotics in Manufacturing
The contributions to this volume clearly reveal the effectiveness and great significance of the techniques
available and, with further development, the essential role that they will play in the future. I hope that
practitioners, research workers, students, computer scientists, and others on the international scene will
find this set of volumes to be a unique and significant reference source for years to come.
Cornelius T. Leondes
Editor
© 2001 by CRC Press LLC
Editor
Cornelius T. Leondes, B.S., M.S., Ph.D., emeritus professor, School of Engineering and Applied Science,
University of California, Los Angeles has served as a member or consultant on numerous national
technical and scientific advisory boards. He has also served as a consultant for numerous Fortune 500
companies and international corporations, published over 200 technical journal articles, and edited
and/or co-authored over 120 books. He is a Guggenheim Fellow, Fulbright Research Scholar, and Fellow
of IEEE, and is a recipient of the IEEE Baker Prize Award and the Barry Carlton Award of the IEEE.
© 2001 by CRC Press LLC
Contributors
Gabriella M. Acaccia Bruno Maione Roberto P. Razzoli
University of Genova Politecnico di Bari University of Genova
Genova, Italy Bari, Italy Genova, Italy
Massimo Callegari Ernest L. McDuffie Stephen E. Sorensen
University of Genova Florida State University Hughes Information Technology
Genova, Italy Tallahassee, Florida Systems
Aurora, Colorado
Franco Caron Rinaldo C. Michelini
Massimo Tronci
Politecnico di Milano University of Genova
Milan, Italy Genova, Italy University of Rome “La Sapienza’’
Rome, Italy
Marco Cristofari Rezia M. Molfino
Biagio Turchiano
Florida State University University of Genova
Politecnico di Bari
Tallahassee, Florida Genova, Italy
Bari, Italy
Stantcho N. Djiev Andrew Y.C. Nee
William J. Wolfe
Technical University of Sofia National University of Singapore
University of Colorado at Denver
Sofia, Bulgaria Republic of Singapore
Denver, Colorado
Sebastian Engell S.K. Ong Konrad Wöllhaf
Universität Dortmund National University of Singapore Universität Dortmund
Dortmund, Germany Republic of Singapore Dortmund, Germany
Maria Pia Fanti Luben I. Pavlov Swee-Hock Yeo
Politecnico di Bari Technical University of Sofia Nanyang Technological University
Bari, Italy Sofia, Bulgaria Republic of Singapore
Martin Fritz Giacomo Piscitelli Zhengxu Zhao
Software Design & Management AG Politecnico di Bari University of Derby
Ratingen, Germany Bari, Italy Derby, United Kingdom
© 2001 by CRC Press LLC
Contents
Chapter 1 System Approach to the Design of Generic Software
for Real-Time Control of Flexible Manufacturing Systems (FMS)
Maria Pia Fanti, Bruno Maione, Giacomo Piscitelli, and Biagio Turchiano
Chapter 2 Computer-Integrated Assembly for Cost Effective Developments
Rinaldo C. Michelini, Gabriella M. Acaccia, Massimo Callegari,
Rezia M. Molfino, and Roberto P. Razzoli
Chapter 3 Multi-Level Decision Making for Process Planning
in Computer-Integrated Manufacturing (CIM) Systems
Zhengxu Zhao
Chapter 4 A Computer-Aided and Integrated Machining System
Swee-Hock Yeo
Chapter 5 Intelligent Set-Up Planning Systems for Parts Production
in Manufacturing Systems
S.K. Ong and Andrew Y.C. Nee
Chapter 6 Object-Oriented Modeling and Simulation of
Multipurpose Batch Plants
Sebastian Engell, Martin Fritz, and Konrad Wöllhaf
Chapter 7 Scheduling Systems and Techniques in Flexible
Manufacturing Systems
Ernest L. McDuffie, Marco Cristofari, Franco Caron, Massimo Tronci,
William J. Wolfe, and Stephen E. Sorensen
Chapter 8 Automated Systems Techniques for On-Line Quality
and Production Control in the Manufacture of Textiles
Stantcho N. Djiev and Luben I. Pavlov
© 2001 by CRC Press LLC
1
System Approach
to the Design
of Generic Software
for Real-Time
Control of Flexible
Manufacturing
Systems (FMS)
1.1 Preface
1.2 Dedication
1.3 Introduction
1.4 Fundamental Steps of the Modeling Process
1.5 Specification of the Model Static Structure
Workstations • Transport System
1.6 Queuing Network Configuration
Production Activity Configuration • Job
Configuration • Server Configuration • Transport System
Configuration • Definition of the Queuing Network
Configuration
1.7 Scheduling Policy
1.8 The Discrete Event Dynamic System Model
Maria Pia Fanti Events • The DEDS Model
Politecnico di Bari 1.9 An Example of How the Modeling Process
The Model Static Structure of the Application Example • The
Bruno Maione
Queuing Network Configuration of the Application
Politecnico di Bari Example • The Applied Scheduling Policy
1.10 The Generic Control Software Organization
Giacomo Piscitelli
The Control Hierarchy • Objects and Architecture
Politecnico di Bari
of the Control Software
Biagio Turchiano 1.11 Conclusions
Politecnico di Bari Appendix: List of Principal Symbols
1.1 Preface
The control system is the core of any flexible manufacturing system (FMS) because it confers to the plant
the capability to absorb internal changes and external fluctuations in demand and in production environ-
ment. However, the technical literature has repeatedly documented that poor control software design is
the major source of difficulties in implementing FMSs. Namely, the FMS potentiality is not yet fully utilized,
because typical, contemporary control software packages are still proprietary and do not possess flexibility
and genericity. On the contrary, reducing the programming and reprogramming effort needs a generic
software usable in an arbitrary FMS, producing an arbitrary part mix.
To design a generic software, two main problems must be solved. The former is to define an abstract
formalism representing both hardware/software components of the FMS and the production plans. The latter
consists in identifying a modular architecture of the control software capable of integrating standard modules.
To solve the first problem, we use a system approach leading to a discrete event dynamic system (DEDS)
that constitutes a formal framework providing information on both the current operating conditions of
the shop floor (SF) and the production progress. To face the second problem, we use the object-oriented
approach to design the kernel of the generic control software. The resulting modular architecture is
organized so that modules and interfaces among them can be replaced without altering the overall
functionality.
1.2 Dedication
To our parents
Maria Pia Fanti, Biagio Turchiano
To the memory of my parents
Bruno Maione
1.3 Introduction
In recent years, the worldwide competition and the growing demand for a high variety of products have
emphasized the role of production systems. In particular the FMSs are of increasing importance because
they have the capability to face changes in production environment and to combine the efficiency of the
mass-production lines with the flexibility of job-shops producing a variety of products in small- or
medium-size batches. In any FMS, control software plays a key role since it can allow optimization of
both hardware (numerically controlled machines, material handling devices, buffers, etc.) and software
(information flow, data base content, etc.). Moreover FMS control should offer adaptive and dynamic
features to absorb internal and external changes and to use all the resources efficiently. However, the
literature has repeatedly documented that information flow and control software are the primary sources
of difficulties in implementing FMSs. Namely, as a result of their proprietary nature, typical contemporary
software packages for controlling manufacturing systems suffer from lack of flexibility and of genericity.
They enable particular productivity improvements and focus on particular aspects of a specific plant.
On the contrary, a generic software is necessary—usable in an arbitrary FMS producing an arbitrary part
mix and minimizing the programming and reprogramming effort.
To design a generic and flexible control software, two main problems emerge. The first one is that
effective control of the FMS activities depends on the existence of a formalism consisting of a unifying
abstraction upon which a comprehensive and consistent knowledge base can be constructed. For this
reason, the search for appropriate frameworks, taking into account the system operation, underlies recent
efforts in the area of flexible automation Naylor and Maletz [14], Naylor and Volts [15]. The second
problem consists in identifying an appropriate, modular software architecture capable of integrating
standard software modules, e.g., for data base management, for field-events detection, and so on. More-
over, if there is the necessity, the modules of this architecture should be changeable to take into account
specific instances of particular FMSs without changing the software main structure and interfaces among
different parts.
To solve the first problem, we refer to Zeigler’s approach [20], [21], [22] which describes DEDS by using
a set-theoretic formalism based on system theory concepts of Zadeh and Desoer [19], Wymore [18], and
many others. In our approach the DEDS state encompasses information on both the current operating
conditions of the SF and the progress of the programmed production. Moreover it includes a logic com-
ponent collecting the decision rules necessary to resolve conflicts arising in the resource allocation. The
information on the SF operating conditions and on the production progress is described using the
primitive concepts of entities, entity attributes, and relationships between entities themselves, all
organized in a relational structure [2] updated at each event occurrence. The decision rules, appearing as
system state components, can be changed at any instant. Due to the formal structure of these rules, one
can establish the information necessary to support the decision making.
The approach followed to define the DEDS state is transparent and has some advantages. First of all,
it allows a detailed and modular description of the production system. Major details can be given, if
necessary, by enriching the state with further entities, attributes, and relationships. Moreover, the model
allows us to describe a generic FMS, producing an arbitrary part mix, under an arbitrary scheduling
policy. Finally, the mechanism for state updating and the definition of all the exogenous events triggering
such transitions lead to a DEDS model that completely describes the FMS behavior at job release and
flow management levels.
To face the second problem, we consider the operation control of FMS from a model reference point
of view. Our approach consists in driving the SF so that it follows the dynamics of the reference DEDS
model. Indeed, this model establishes how the plant should respond to the command signals and interacts
both with the higher level (production planning) and with the lower one (hardware components). The
resulting control architecture emerges as direct consequence of this idea of utilizing the DEDS formulation
to define the kernel of a generic software driving the dynamics of the actual FMS. Inspired by the works
of Naylor and Volts [15], Naylor and Maletz [14], the paper [7] considerably improves and generalizes
the formalism proposed in [5], necessary to develop a generic control software at the job release and
flow management levels. Moreover, in the same line of [7], we emphasize the principles of structure,
orderly partitioning, and modularity by using an object-oriented approach to design the control software.
Namely, we decompose the control software into modules (objects) which encapsulate both data and
procedures (methods) characterizing their behavior and which interact by sending one another messages.
In addition the role and the interfaces of such objects remain unchanged, even if the FMS modifies its
configuration to fit particular production needs. These characteristics are key features when the reuse of
existing software (i.e., for planning, hardware components for managing data base, etc.) is one of the
main objectives.
The organization of this contribution is as follows. The general methodology for building the sequen-
tial state of the DEDS model is the main concern of Section 1.4. Sections 1.5 and 1.6 specify the basic
entities, relationships, and attributes defined on the entity sets. Section 1.7 introduces the formal rep-
resentation of the decision rules that govern the flow of the transitional entities. Section 1.8 completes
the DEDS model by defining events, DEDS state, model clock and mechanism for event-driven state
transitions. Section 1.9 applies our formalism to a case study. Section 1.10 discusses the organization of
a generic control software, as it emerges from the DEDS formulation. Finally, Section 1.11 draws the
conclusions.
1.4 Fundamental Steps of the Modeling Process
To build an abstract comprehensive framework, we must specify the circumstances and restrict the aspects
under which we consider the system. In other terms, we have to define an experimental frame. In respect
to this fundamental point, we observe that even if the real behavior of the manufacturing plant involves
variables changing continuously over time, the DEDS model abstracts from this behavior and records the
occurrence of certain discrete events only. Namely, we consider the evolution of the manufacturing plant
as a record (or a trace) of the occurrence of certain discrete, qualitative changes in the system, and ignore
continuously occurring micro-changes. This is because we can describe the behavior of an FMS by means