Emergence of intelligence in next-generation manufacturing systems

In the paper we propose a fundamental shift from the present manufacturing concepts and problem solving approaches towards new manufacturing paradigms involving phenomena such as emergence, intelligence, non-determinism, complexity, self-organization, bottom-up organization, and coexistence with the ecosystem. In the first part of the paper we study the characteristics of the past and the present manufacturing concepts and the problems they caused. According to the analogy with the terms in cognitive psychology four types of problems occurring in complex manufacturing systems are identified. Then, appropriateness of various intelligent systems for solving of these four types of problems is analyzed. In the second part of the paper, we study two completely different problems. These two problems are (1) identification of system in metal forming industry and (2) autonomous robot system in manufacturing environment. A genetic-based approach that imitates integration of living cells into tissues, organs, and organisms is used. The paper clearly shows how the state of the stable global order (i.e., the intelligence) of the overall system gradually emerges as a result of low-level interactions between entities of which the system consists and the environment.     

An integrated manufacturing planning assistant — IMPA

In this paper, we describe our development of a fully integrated manufacturing planning assistant (IMPA) system, which is able to: (1) interpret the finished part requirements directly from the designer's CAD systems or solid modelers without user intervention or special feature coding; (2) check the machinability of a designed part; (3) automatically generate a process plan, a tool path and an NC (numerically controlled) code, and (4) support interactive user modification of the resulting plans, tool paths and NC code. A demonstration version of the system was designed to provide automated assistance for the planning of machining processes on three-axes NC machine tools. The underlying architectural concepts and reasoning algorithms can be extended to more complex machines such as four-or-more-axes NC machines. CAD, CAE, and CAM including robotic, FMS (flexible manufacturing system) and NC machines are widely used in industry today. There is increasing interest in automation of factory control software Merchant, (1988); this includes automating the generation of the control programs — that is, in developing systems which will automatically produce the NC code for machining the part, given a model of the part, the shape of the raw material, and the machine specifications. With such systems, there are several difficulties in the manual preparation of an NC program code such as, long and tedious calculations, high risk of error in data preparation, etc., which need to be eliminated. This is a critical step toward the integration of CAD and CAM into a truly concurrent engineering and manufacturing environment.     

Expert systems in production planning and scheduling: A state-of-the-art survey

Intelligent solutions, based on expert systems, to solve problems in the field of production planning and scheduling are becoming more and more widespread nowadays. Especially the last decade has witnessed a growing number of manufacturing companies, including glass, oil, aerospace, computers, electronics, metal and chemical industries—to name just a few—interested in the applications of expert systems (ESs) in manufacturing. This paper is a state-of-the-art review of the use of ESs in the field of production planning and scheduling. The paper presents famous expert systems known in the literature and current applications, analyzes the relative benefits and concludes by sharing thoughts and estimations on ESs future prospects in this area.     

Simulation aided design of organizational structures in manufacturing systems using structuring strategies

This paper presents a simulation aided approach for designing organizational structures in manufacturing systems. The approach is based on a detailed modeling and characterization of the forecasted order program, especially of elementary processes, activity networks and manufacturing orders. Under the use of the organization modeling system FORM, that has been developed at the ifab-Institute of Human and Industrial Engineering of the University of Karlsruhe, structuring strategies—e.g., a process-oriented strategy—can be applied in order to design organizational structures in manufacturing systems in a flexible and efficient way. Following that, a dynamical analysis of the created manufacturing structures can be carried out with the simulation tool FEMOS, that has also been developed at the ifab-Institute. The evaluation module of FEMOS enables to measure the designed solutions with the help of logistical—e.g., lead time degree—and organizational—e.g., degree of autonomy—key data. This evaluation is the basis for the identification of effective manufacturing systems and also of improvement potentialities. Finally, a case study is presented in this paper designing and analyzing different organizational structures of a manufacturing system where gear boxes and robot grip arms were manufactured.     

Integration and control of intelligence in distributed manufacturing

The area of intelligent systems has generated a considerable amount of interest—occasionally verging on controversy—within both the research community and the industrial sector. This paper aims to present a unified framework for integrating the methods and techniques related to intelligent systems in the context of design and control of modern manufacturing systems. Particular emphasis is placed on the methodologies relevant to distributed processing over the Internet. Following presentation of a spectrum of intelligent techniques, a framework for integrated analysis of these techniques at different levels in the context of intelligent manufacturing systems is discussed. Integration of methods of artificial intelligence is investigated primarily along two dimensions: the manufacturing product life-cycle dimension, and the organizational complexity dimension. It is shown that at different stages of the product life-cycle, different intelligent and knowledge-oriented techniques are used, mainly because of the varied levels of complexity associated with those stages. Distribution of the system architecture or system control is the most important factor in terms of demanding the use of the most up-to-date distributed intelligence technologies. A tool set for web-enabled design of distributed intelligent systems is presented. Finally, the issue of intelligence control is addressed. It is argued that the dominant criterion according to which the level of intelligence is selected in technological tasks is the required precision of the resulting operation, related to the degree of generalization required by the particular task. The control of knowledge in higher-level tasks has to be executed with a strong involvement of the human component in the feedback loop. In order to facilitate the human intervention, there is a need for readily available, user-transparent computing and telecommunications infrastructure. In its final part, the paper discusses currently emerging ubiquitous systems, which combine this type of infrastructure with new intelligent control systems based on a multi-sensory perception of the state of the controlled process and its environment to give us tools to manage information in a way that would be most natural and easy for the human operator.     

Software support tools for construction of interactive problem-solving systems

The class of so-called route systems is described—systems of productions with dynamic scheduling of stepwise interactive computations. Automated manufacturing of such systems in the DISUPP support system is based on the synthesis of two models: a model of the application domain and a communication model.Translated from Kibernetika, No. 6, pp. 17–27, November–December, 1989.     

RTMMS—An OSI-based real-time messaging system

A critical component of the MAP initiative has been the development of a message handling system—initially designed for manufacturing environments—termed MMS. In terms of the OSI model, this application-layer system is designed to support communications to and from programmable devices, specifically in manufacturing, and, more recently, in process-control environments as well. MMS also permits specific, application-oriented messaging systems to be built around the core definition of MMS—these additional systems being termed companion standards. However, although dedicated to such real-world environments, MMS does not have a direct capacity to support time-critical services. It has been recognized that such capabilities are vital in many areas of control, and therefore work needs to be undertaken to extend MMS to cover this field. This paper addresses some of the issues where MMS, in its standardized form, falls short, and suggests what can be done to overcome these difficulties. It proposes additions to the MMS profile, and basically, therefore, to the Virtual Manufacturing Device which underlies the MMS system. In the context of the paper, it should be noted that Real-time MMS is not designed as a replacement for the Manufacturing Messaging Specification, but rather functions alongside it. The paper concludes by illustrating how such real-time extensions may be implemented.     

Integrity constraints of manufacturing data bases

Today's manufacturing cost reduction and competitiveness largely depends on the application of automated manufacturing. Automated manufacturing could be even more efficient if computerizations of the process is taken one step further—to the integration of the design and manufacturing processes by means of or through a well-structured data base. This paper refers to several important issues related to integrity constraints in relational data bases. The literature review provides a summary of what has been done in this area by other researchers. In addition, some of the concepts proposed, developed, and even implemented before are introduced. A brief look at the classification of integrity constraints is performed by examining the real world and engineering and manufacturing worlds. This classification is supported by various manufacturing examples for each type of integrity constraints. Further, we discuss the issues of how to express and manage integrity constraints in relational data bases with particular emphasis on manufacturing applications.     

Criteria for selecting control systems in flexible manufacturing

Industry in Europe has been undergoing major structural changes during the last twenty years or so. Against the background of high demand for consumer and capital goods with corresponding, mostly fixed production capacities, it was necessary to build flexible and, at the same time, efficient production plants in order to cope with the increasing variety of products and shorter innovation cycles.Flexible manufacturing is inconceivable without information technology. Thus, the word “information” has rightly taken its place in the list of primary factors associated with modern production technology. The “gating” of data into production planning and quality assurance, combined with concepts of logistics and control, keeps the flow of materials on the move and helps to shorten lead times.The organization of production and the plant equipment itself have to be matched to the size of the plant, the product range and the market. In large-batch production, for example, a customized vehicle is required; in small-batch or unit production it is often necessary to manufacture a machine to specific customer requirements. Despite such great variations in the type of requirement, it is still possible to distinguish a number of common factors—one of them being the hierarchical structure of the automation landscape with objective and transparent distribution of information across all levels; from the control level for pre-production, assembly and transport up to the planning level for capacity planning and materials management.Hierarchical levels enable particular tasks to be assigned to specific automation equipment. Mainframes and minicomputers are used at the planning level. Dedicated systems such as numerical controls and programmable controllers are now used almost exclusively on the shopfloor control level.Local area networks connect the automation systems of different manufactures without the need for any adaptation. Protocols must be unified for this purpose. Since stable standards are not yet in existence, Siemens has decided to follow the strategy of standard harmonized development.Programmable controllers are part of all production, transport and storage systems. The main requirements are for control, operator communication, monitoring, counting and positioning. A comprehensive production family is a very important factor. Excellent hardware compatibility, easy interlinking and a uniform programming language are all characteristic of the family philosophy.Industrial robots are used mainly in the automobile industry. Largely thaks to them it is possible to produce economically and rationally any mix of model variants and to automate assembly. Programming facilities such as teach-in, on-line or off-line are therefore an important selection criterion for robot control.The majority of numerical controls in use today are used for controlling single machines in heavy-duty and special-purpose machinery manufacture. In networked applications, numerical controls form part of flexible manufacturing systems. In addition to machine control and management, the capacity for communication is an important criterion for selection in this case.In many controls for individual machines the priority is for quick and easy programming. “Shopfloor programming” has assumed considerable importance in such applications. Shopfloor programming requires controls with a sophisticated, user-friendly, graphics interface.Examples show how dedicated automation subsystems have been finding widespread application in the automation of manufacturing, transport and warehouse equipment. They are designed specially to perform certain tasks, both in programming and operation, in order to provide an economic solution to a problems in terms of matched performance and functionality.     

A logical approach to representing and reasoning about space

The need for a formal language in which to express and reason about spatial concepts is of crucial importance in many areas of AI and visual systems. For the last five years, spatial reasoning research by the Qualitative Spatial Reasoning Group, University of Leeds, has centred on the development and application of such a language — the RCC spatial logic. Below, we briefly describe the work of the group in this area.     

Verifying Programs with Unreliable Channels

We consider the verification of a particular class of infinite-state systems, namely systems consisting of finite-state processes that communicate via unbounded lossy FIFO channels. This class is able to model, e.g., link protocols such as the Alternating Bit Protocol and HDLC. For this class of systems, we show that several interesting verification problems are decidable by giving algorithms for verifying (1) thereachability problem—is a finite set of global states reachable from some other global state of the system ? (2)safety properties over tracesformulated as regular sets of allowed finite traces, and (3)eventuality properties—do all computations of a system eventually reach a given set of states? We have used the algorithms to verify some idealized sliding-window protocols with reasonable time and space resources. Our results should be contrasted with the well-known fact that these problems are undecidable for systems with unboundedperfectFIFO channels.     

Monitoring distributed real-time systems

This paper emphasizes the power ofmonitoring of distributed real-time systems as a promising tool for both scientific work and practical purposes. Starting out from a number of well-known problems with today's (industrial) real-time systems, a classification of remedial monitoring applications is given. The most important features of a monitoring system suitable for such purposes are discussed and related to the current research into monitoring of (general) distributed systems. Finally, some of the resulting conceptual issues underlying our prototype VTA monitoring system—currently being under development at our department—are presented.     

Growth Phenomena — Algebraic and Geometric Descriptions

An enormous variety of nonlinear dynamical systems can be — by suitable introduction of new coordinates — represented in the form of polynomial systems and then can be reduced to Volterra systems, where the nonlinearities are at most quadratic. In this paper, we discuss a link between systems of differential equations with homogeneous quadratic polynomial vector fields and non-associative algebras on the one hand and the question of representation of such systems as geodesics in some Finsler spaces on the other hand.     

Pragmatism and purism in artificial intelligence and legal reasoning

The paper identifies and assesses the implications of two approaches to the field of artificial intelligence and legal reasoning. The first — pragmatism — concentrates on the development of working systems to the exclusion of theoretical problems. The second — purism — focuses on the nature of the law and of intelligence with no regard for the delivery of commercially viable systems. Past work in AI and law is classified in terms of this division. By reference to The Latent Damage System, an operational system, the paper articulates and responds to conceivable purist (jurisprudential and AI) objections to such a program. The methods of the pragmatist are also called into question and refined. The author concludes that pragmatism within a purist framework is the only sound approach to developing reliable AI systems in law.     

Modeling Reactive Multimedia: Events and Behaviors

This paper explores the idea of reactivity in multimedia, and proposes systems which can react to continuously-evolving behaviors as well as to more traditional discrete events. The idea is presented in a scenario as well as in a number of small programming examples.The illustrative examples are written in the Fran system. Fran provides a high-level programming model for animations, built in the Haskell functional programming language. Whilst we use Fran for illustration—and indeed we argue that the functional paradigm is a natural choice of host for such a system—we should stress that the notion of external behaviors within multimedia is independent of the programming environment chosen and could be incorporated into other systems such as SMIL.     

The state of the art in intelligent real-time FMS control: a comprehensive survey

Flexible manufacturing systems (FMS) have been developed with the hope that they would provide a means to tackle a threefold challenge — better quality, lower cost and shorter lead times — by integrating machine tools, robots, material handling and storage systems, and computers. Control of the integrated system presented a new set of problems as well as challenges, which have been receiving considerable attention from the academic community as well as from industrial system users. Intelligent control, which involves using computers to assist in decision making at various stages of the control process, has been advocated by many researchers as a possible avenue to reach a solution to these problems. This paper provides a review of the state of the art in intelligent control of FMS, in an attempt to supplement earlier general reviews via a more focused perspective. The principles of several techniques, namely simulation, knowledge based, example based, petri nets, and hybrid approaches are briefly introduced, and publications are reviewed, followed by discussions ontheir potential. Suggestions for further research and development are also enumerated.     

Cooperation without deliberation: A minimal behavior-based approach to multi-robot teams

While terminology and some concepts of behavior-based robotics have become widespread, the central ideas are often lost as researchers try to scale behavior to higher levels of complexity. “Hybrid systems” with model-based strategies that plan in terms of behaviors rather than simple actions have become common for higher-level behavior. We claim that a strict behavior-based approach can scale to higher levels of complexity than many robotics researchers assume, and that the resulting systems are in many cases more efficient and robust than those that rely on “classical AI” deliberative approaches. Our focus is on systems of cooperative autonomous robots in dynamic environments. We will discuss both claims that deliberation and explicit communication are necessary to cooperation and systems that cooperate only through environmental interaction. In this context we introduce three design principles for complex cooperative behavior—minimalism, statelessness and tolerance—and present a RoboCup soccer system that matches the sophistication of many deliberative soccer systems while exceeding their robustness, through the use of strict behavior-based techniques with no explicit communication.     

A multi-layered architecture for sketch-based interaction within virtual environments

In this article, we describe a multi-layered architecture for sketch-based interaction within virtual environments. Our architecture consists of eight hierarchically arranged layers that are described by giving examples of how they are implemented and how they interact. Focusing on table-like projection systems (such as Virtual Tables or Responsive Workbenches) as human-centered output-devices, we show examples of how to integrate parts or all of the architecture into existing domain-specific applications — rather than realizing new general sketch applications — to make sketching an integral part of the next-generation human–computer interface.     

Symbolic computation in nonlinear dynamics

This paper gives examples of how computer algebra systems can help us to understand nonlinear dynamical systems and their numerical simulations. We caution against naive use of exact arithmetic, but we give examples where elementary use is helpful. We also look at the use of polynomial computations — such as factoring, computation of discriminants, and Gröbner bases — in bifurcation studies.This paper is dedicated to the memory of M. A. H. Nerenberg (1936–1993).     

Tractability through symmetries in propositional calculus

Many propositional calculus problems — for example the Ramsey or the pigeon-hole problems — can quite naturally be represented by a small set of first-order logical clauses which becomes a very large set of propositional clauses when we substitute the variables by the constants of the domainD. In many cases the set of clauses contains several symmetries, i.e. the set of clauses remains invariant under certain permutations of variable names. We show how we can shorten the proof of such problems. We first present an algorithm which detects the symmetries and then we explain how the symmetries are introduced and used in the following methods: SLRI, Davis and Putnam and semantic evaluation. Symmetries have been used to obtain results on many known problems, such as the pigeonhole, Schur's lemma, Ramsey's, the eight queen, etc. The most interesting one is that we have been able to prove for the first time the unsatisfiability of Ramsey's problem (17 vertices and three colors) which has been the subject of much research.