Factory environment and CIM

Robotics & Computer-lntegrated Manufacturing, Vol. 7, No. 3/4, pp. 213-228, 1990 Printed in Great Britain

•

0736-5845/90 $3.00 + 0.00 © 1991 Pergamon Press pie

Invited Presentation FACTORY ENVIRONMENT A N D CIM VLADIMIR R. MILA(~I(~ Institute of Production Engineering and CIM, Mechanical Engineering Faculty, University of Beograd, Yugoslavia

This contribution on the topic of factory environment and CIM is divided into two parts. The first part deals with some fundamental aspects of intelligent manufacturing systems for the new generation of factories. This subject is divided into three blocks: intelligent manufacturing systems, expert systems and intelligent CAE/CAD/CAM. Based on the input-output approach, some basic requirements for IMS definition are given. The second part deals with the problem of the factory environment and CIM, more specifically from historical aspects to the contemporary factory and some conceptual design aspects of FMS. At the end, an example of structural pattern recognition of FMS is given.

1.1. Structure and its elements for I M S In the overall structure, IMS is the first member which, when decomposed from the adopted cascade structure, is as shown in Fig. 2. In this case we have three inputs, 10, I 1 and 05, and one output 01. Each of these inputs and the output are a complex matrix function difficult to describe mathematically. Therefore, only some of the members of these functions are quoted here.

1. IMS FOR THE NEW GENERATION OF FACTORIES Within the scientific program for research in the field of intelligent manufacturing systems, a general structure with various main parts may be defined. The scientific program has three entities with numerous inputs and outputs. The decomposition of such a structure is achieved according to stratification and layer principles. The structure is therefore multilevel with an integral decomposition. The overall structure of the scientific research program has inputs-outputs as well as the main research areas which are the developing blocks of processes. The following process blocks were adopted: • • •

block 1--intelligent manufacturing (IMS), block 2--expert systems (ES), and block 3--inteUigent CAE/CAD/CAM.

Input 10 (Table 1). This input may be defined with the following characteristics: (101) engineering products with high level of machining; (102) exclusive products; (103) increase in workers' productivity; (104) decrease of product delivery time; (105) extended product lifetime; (106) factory and system with high intellectual activities; and (107) diversity of commerical products.

systems

The inputs and outputs are marked with corresponding numbers. The overall structure is illustrated in Fig. 1.

'°1 !

IMS

1

Each of these items may be understood as a theorem for the design of intelligent manufacturing systems.

° • OI

I

O5 12

•

°'

2

OI

~

10

O2

.o2

II

~10

15 J CAE/CAD/ [ 05 " CAM 5~ "

•[

]MS ~

E Fig. 2.

Fig. 1. 213

. OI

214

Robotics & Computer-Integrated Manufacturing • Volume 7, Number 3/4, 1990

Table 1. Input 10 101

Engineering products with high level of manufacturing

• Function Complexity

• Share complexity

+Large number of components

Minimum number ~ of components

+ Mechanics and electronics

r Mechatronics

Complex computing manufacture and assembly

+ Compact structure

Complex * manufacturing technology

Complex assembly

Simple ~- assembly

+Minimum number of components • Complex materials

+Composite materials

• Dimensions and tolerances

Designed ~ features of parts

~ Complex manufacturing

+ Dimensioning and tolerances theory

- Miniaturization

Nano-technology

Complex machining measurement and assembly

of products - Large products

102

103

Exclusiveness

Productivity

• Discovery, innovation for new products • Market diffusion • Machines' productivity

• Workers' productivity

i I •

Machine-worker productivity T L

• Worker environment productivity

104

Delivery term

Time economy in factory

t t I

Large dimensions ~- and great complexity

+ Designing of new products + New manufacturing technologies • + New approach to market development + Performance and reliability + Artificial intelligence + Flexibility

105

Product lifecycle

Functions for durability

Materials for durability Technology for durability Multifunctionality for durability

' Product , model

- Society's synthetic • productivity

' I + Know-how (skills)

[ + Knowledge--intelligenceFlexibility ~1 + ]+ + +

I I

l

Integration Supervision Intelligence Flexibility

.~ J + Inside manufacturing system I + outside manufacturing system + Disturbances Level of functionality in factory

• I + Technological cycle (Tcr)

I

+ Manufacturing cycle (Tco)

Time economy in environment

Complex machining, dimensions measuring and assembly

~J+ I + +

Normative-administration cycle (TcNA) Communication cycle (Tct) Transportation cycle (TcT)

Level of environment's functionality

+ Mobile into immobile elements + Processes without friction and wearing

I + Materials resistant to wearing and corrosion + Materials resistant to other changes J + Surface protection * + New manufacturing processes

I

~- I + Multipurpose machines with constant configuration + Multipurpose machines with changeable configuration

I

] V Reliability

---1

I !

-- I V Effectiveness I V Halfperiod of I product's ~"I lifecycle

fr ~ max

f s "* m a x

Factory environment and CIM • V. R. MILACI(2

215

Table 1 (contd).

106

Factory with high intellectual activities

+ Elimination of barrier between direct and indirect work

• Direct work

• Indirect work

V Level of heterarchical , structure * max

' I + Creation of environment for work and thinking processes

I

+ Creation of conditions for creative work as a pleasure for a group of people + Overcoming administratively prescribed hours for creation and work

• Homogenization of work outside working hours

107

Diversity of commerical products

Diversity in one family

I-

+ Direct inheritance + Indirect inheritance in

V Level of work creativity

max

I V New family-based products

in a family(fertilization) Diversity as symbiosis of technologies

+

Mutation of technologies

Brief comments are made for some of them after designating them as the matrix:

[107

Enoineerin9 products with hioh level of machinin9 (101) may include a wide range of features, such as function and shape complexity, complexity of component materials, dimensions and accuracy, etc. All this may be represented as a submatrix of the previous matrix:

/] SO

{101} =

sM

DiT

where SF is the complexity of the function, SO is the complexity of the shape, SM is the complexity of material used, and DiT is the dimensions and tolerances. The complexity of the function (SF) of a set or a product depends, as a rule, on the structure complexity expressed through an increased number of components to carry out such a function and frequently a simultaneous complexity of the shape of each component and the complete product. However, a new philosophy based on artificial intelligence assumes in fact that the products have a minimum number of components representing the symbiosis of materials, mechanical structures and electronic assemblies for the performance of a given function. This decreases the number of components, but increases the complexity of shapes. The second characteristic is the symbiosis of the different properties of components. Examples of research undertaken in this direc-

~'- V Mutation-based products

tion are presented. The body of a car is composed from several hundreds of elementary surfaces. With the introduction of composite materials this number of elements was decreased to only a few, thus reducing assembly operations to a minimum. The increase in the number of functions of an assembly or a product, on the other hand, presupposes combining mechanical engineering and electronics, i.e. the creation of mechatronic structures. The symbiosis of mechanical engineering and electronics is not a mechanical merging of two technologies into one, but it implies their adjustment and conforming to avoid the effect of a "reaction to the foreign body" in the structure. Imagine an assembly with a box into which a multilayer plate with electronic components is mounted. Thermal stress and the functional demands of the given assembly require complex calculations as well as an adequate solution of this mechatronic assembly. A greater number of functions is realized through the complexity of the shape (SO) and compact structure. This generates new curves and surfaces extremely difficult to manufacture. The complexity of material (SM) requires the design of the properties of materials on the basis of designed functions. This is particularly evident in the composing of features and shapes of composite materials. All these features may have both mechanical and complex functional features. Dimensions and tolerances (DiT) are still a great puzzle for designers, although they are used from the very beginning of the design and manufacturing process of engineering products. The first period, which still exists, is characterized by the possibility of discovering the logic for dimensioning and tolerances, so that everything is in the hands of the designer and his skill and intuition. The second category of problems is related to the fast orientation to miniaturization, although it also includes gigantic engineering products as well. Thus, in the case of miniaturization a

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Robotics & Computer-IntegratedManufacturing • Volume7, Number 3/4, 1990

jump is made from the domain of micro- to nanotechnology which radically changes everything. If the shift is made from the large systems, similar demands are faced which correspond to such big dimensions, naturally. The problem of accuracy in products of large dimensions is not much easier to solve than the preceding nano-technological problems. The advantage is that according to the first impression the problems stand in closer proximity to the systems of medium dimensions. Considering the problem of the determination of dimensional accuracy it may be concluded that it is essential to define special methods for this task. Nano-technological tasks are so important that they largely determine the manufacturing system as well, and a certain measure of intelligence. Some of these fundamental aspects of this input point to the complexity of the expression of this member of the submatrix, and particularly to the possiblities for its formulation. Exclusive products (102) are the products which may be produced and offered to the market by a small number of manufacturers or by one manufacturer only. The exclusivity, in fact, points to the uniqueness or to the monopoly of one factory in the manufacture of one product or its placement at the market. What is hidden behind this characteristic? First of all an intensive capability for discovery, and the innovation process to transfer the discovery into an economic category, that is into manufacturing and market diffusion. It is difficult to support this logic with practical technological solutions. Let us quote an example from a recent period. The manufacture of TV cameras required an obligatory development of a series of manufacturing technologies for this very complex product. The same may be noted in the manufacture of shop-floor systems for reading computer disks. This means that a very extensive research program and the development of new design methods, new materials and manufacturing processes preceded the production of this product. 7he increase in the productivity of workers (103) is a very complex demand, because it concerns the man and his entire environment together with other men and machines, and their macro-environment. The second change occurs in the measurement and expression of this productivity. Until the present, as a rule, this productivity in its more narrow sense was expressed by the number of manufactured pieces (parts, assemblies, products) per unit time or by the quantity of chip machining. The first definition does not give a synthetic expression of productivity, while the second one is less real. This means that a new approach should be found for the expression of the productivity of workers, as production is increasingly becoming the symbiosis of know-how, information processing and knowledge. Therefore, the expression of workers' productivity should be sought by linking these three aspects, the result of which is the product itself. On the other hand, an increasing redistribution of functions between machines and workers occurs, so that it is

now possible to speak about the productivity of workers, productivity of machines and the productivity of an inter-connected relation of men--the workers - - a n d machines. The latter is frequently expressed through the level of the adaptability of machines to the man or, as in case of computers, user friendliness. Reduction of delivery time (104) is one of key orientations for the building of the new generation of factories. Manufacturing systems and factories are characterized today by very low economy of time in the cycle between the issuance of an order to the delivery of a product. According to analyses, about 5 ~ of the total time in the production cycle is spent adding to the value of the product, while the value of the product does not change during the other part of the manufacturing cycle (waiting, transport, filling in of documents, etc.). The aim is, therefore, an extensive increase in the share of production in the manufacturing cycle, so that the level of functionality of the production system may reach a maximum:

TOT --. max Top

f = --

where: TCT is the duration of the manufacturing cycle and Tcp is the duration of the production cycle. This can be achieved with the building of a new modelling concept of the product itself. The extension of the product's lifetime (105) also represents a fundamental change in the attitude to the product itself. At the time of the construction of pyramids, churches and other similar products the ethic of engineers of that time was directed to the durability of the "work of their hands". With the development of engineering consumer goods, this ethic was transformed into the ethic of the consumer society. We are now entering into a new period of development when a new ethic resembling that from the first period will be needed. This means that now the ethic of engineers in the manufacture of engineering products should be based on much longer product lifetimes. This ethic, at the present level of development of human consciousness, is directly opposed to man's yearning for a dynamic and innovative life-style. The reconciliation of these two contradictions undoubtedly requires scientific and technological penetration along two lines. The first line is concerned with the materials and the function of the product itself, i.e. if it deals with mechanical mobile parts then the elimination of corrosion and wear will provide the basis for the extension of the lifetime of a product. In a word, it is necessary to run against "wearing"--the effects of time. The second line of scientific and technological effort is the modelling of a product with an inherent capability for change in time according to the user's requirements, achievable through modifications or extensions of its own functions. This is extremely difficult and practically insoluable at the present level of development, where a design theory with such a capability has not been devised.

Factoryenvironmentand CIM • V. R. MILACIC The factory as a system with high intellectual activities (106) is the environment in which all the above demands are solved, but which at the same time offers special conditions to highly educated experts. An environment with a stimulative effect on creative abilities is exceptionally important for the new generation of factories. This will assume the creation of working and living conditions in the factory which will differ from those based on Taylor's concept. The factory is, first of all, a system in which homogenizat i o n - t h e integration of people participating in direct production--is achieved with the other, greater group of people responsible for the development, marketing and overall functioning of the system in the factory. Working hours and creativity time differ less and less, so that practically the period of provided time comes out of all its determined norms. In order that all this should not seem as a utopia, the example of the FANUC company in Japan should be mentioned, which has applied this concept. However, the implementation of this concept requires the overcoming of historical, social and mental barriers. The diversity of commercial products (107) can be directly linked with all the above component inputs. The diversity of products is, in fact, a very complex problem. When speaking about the diversity of products, variant solutions of a class of products are considered (e.g. automobiles, machine tools, airplanes, household appliances, etc). This primarily relates to inherited features within a family of products which take into account the possibilities of shop-floor production without a satisfactory level of flexibility. However, at the present level of development, this is a fairly limited concept of diversification. The first step over this limiting factor has been already surmounted today by creating diverse products based on the symbiosis of different technologies and different products into new products. This particularly applies to industry in Japan which has changed something called a robot toy into a big robot manufacturing power. This also applies to the manufacture of watches, cameras, video cameras, audio equipment, calculators and others, which through the symbiosis of different parts have created entire classes of new products. This area offers great potential possibilities for the manufacturing of new generations of products in the new generation of factories. The increasing level of technical information possessed by buyers represents a potential source of demand for new variants of product solutions from engineers. Input 11 (Table 2). This second input may be defined in the following way: (111) the new generation of factories should minimize the consumption of power, raw materials and storage space; (112) the manufacturing system should perform highly complex tasks with a high degree of reliability; (113) the manufacturing system should be able to

217

satisfy the level of highly creative personnel, with a developed system of communication between parts within a unique system; (114) the manufacturing system should be highly productive, with the ability to respond quickly to market demands; (115) the manufacturing system should be designed so that manpower is separated from machines both in time and space; and (116) the manufacturing system should be highly flexible. The matrix expression of this input is:

(11}

=

13

.

16 Each of the above inputs may be analyzed in a similar way to the former set of inputs. It is obvious that some of the requirements of the theorem in the first set of inputs are given here in the form of closer formulations (lemmas), which are directly connected with the former. Minimization of power, material and space consumption (111) is a very broad and exigent demand in the building of manufacturing systems. The minimization of power is directly linked with the minimized consumption of material, although it is much more than that. Manufacturing processes for shaping products by their nature determine energy requirements as well, although the materials used determine the consumption of power necessary for their transformation into the designed product. The consumption of energy and material is directly linked to material removed as a surplus (waste-machining) from the product, as well as the dissipation of power during the manufacturing process itself. This imposes the need for the development of new manufacturing processes (technologies in a more narrow sense), as well as new materials providing minimization of power and material for the manufacture of engineering products. The minimization of space is directed towards the minimization of floor space and the maximum utilization of volume; and minimization of transport paths through the construction of aggregate mechanical systems with continuous effect; and the reduction of the size of products for the performance of these tasks. This means that the first condition is to design new manufacturing processes and new materials. The second condition is to design manufacturing machines with minimum power consumption, minimum waste and with the maximum concentration of operations. The latter means that we require machines which will manufacture products and not their components. The third assumption is the establishment of the new production planning and control concept without

Table 2. Input 11 111

Minimization of power, materials and space for manufacturing system

• Existing processes: relation of power and materials

+ Machines with concentrated operations , + Loss of energy + Loss of material

• Spatial compactness of production workspace

In process

+ Aggregate machines for product + Reduction of transport to minimum

Minimum production space

" - ' * + Just-in-time production control + Large systems based on large number of small dimension components 112

Manufacturing system for highly complex and highly productive products

~ ~

• Manufacturing system for product

---~+ Integration of production, assembly and testing

• 24-Hour manufacturing system

113

~__.~

New concept of quality assurance

Products with complex structure and minimum size require new generation of machines and manufacturing systems

+ Miniaturization of components

/

• High reliability of of the manufacturing system

V Multifunctional , manufacturing systems

--~+ Product quality based on flexible adjustment

• Product of limited dimensions (volume) with great number of components ~ - ~

+ Mechanical-electrical components + Mechanical-hydraulicpneumatic-electrical components [

+ Self-diagnosis + Self-maintenance + Capability to work under flexible tolerance conditions (self-adjustment)

I

Minimum by introduction of new processes and materials

Building of highly reliable manufacturing system based on flexibility possessed by man

+ Redristribution of tasks between man and machine

High level manufacturing • New concept of symbiosis system and highly between man and manufacturing educated workers system

+ Natural intelligence of man and artificial intelligence of machines + Man in manufacturing chain is on on-line and off-line based regime

• Organizational structure

+ Hierarchical structure + Heterarchical structure Communication between men Communication between men and machines Communication between men and environment

• Communication structure

• Educated worker

~i

Innovation process

Worker in addition to skill possesses knowledge

[

Multifunctional worker

[

I

~7 Works on several machine !

Flexible to produce custom-ordered product (manufacturing mentality) 114

Highly productive manufacturing system and quick satisfaction of market demands

• Highly productive production methods

~

• New methods for product designing and manufacture

~

+ Methods based on t ~ min, M ~ min, E --, min and P ~ min for product with maximum satisfaction of buyer

- ~ + New methods as manufacturing basis (intelligent CAD/CAM systems)

• Buyer's demands and his ~-,-+ Linking of buyer and factory communication with manufacturing system

!

• Model of product as basis of satisfying procedure

~

+ Building of integral manufacturing system based on data and not on algorithms

Factory environment and CIM • V. R. MILA~I(2

219

Table 2 (contd).

115

Manufacturing system with separation of physical machine and man in space and time

• Human decision-making in off-line regime

~ -+ Off-lineprogramming ~-~+ Expert systems

• New generation of machines based on concentration of operations

~

• Development of system for work in off-lineregime

• Building of inter-connection between machines • Building of TOP/MAP communication system • Diagnostics and maintenance

• Microflexibilityof machines • Macroflexibilityof machines • Automation and flexibility • Machines based on flexibility

stocks of raw materials and work in progress, that is incomplete production. This has been promoted for the first time through the just-in-time (JIT) concept, which should develop into the new manufacturing philosophy. It should be added here that in essence the shift is made towards the manufacture of products of smaller and smaller dimensions, units which are composed into big, or very big, engineering systems.

Manufacturin# systems for products with high complexity and hioh reliability level (112) assume the development of systems for products and not for its parts, with a 24-hour work regime during six days in the week. It was pointed out that the design and manufacture of very complex products with limited dimensions is increasingly taking place. A good example of this is the manufacture of TV cameras and video players, which contain several thousands of parts in a limited volume. More and more stress is placed on the need for manufacturing systems which will produce a complete product and not just its components. The result of this concept is the integration of the manufacturing of parts and assemblies with their assembly and quality inspection. This means that Taylor's decomposition concept is changed into a new concept of computer-integrated manufacture with concentration of operations through to the completion of the product. The reliability of the operation of the manufacturing system should provide for successful work in the domain of the quality assurance of the product and the successful separation of man and machine in time and space. The reliability of the work of the manufacturing system should also be based on the flexible interfacing of components, and not on hard automation. Practically, this means that the interfacing of components based on adjustment is necessary, by

-~+ Conglomerate machines with man's quality of flexibility

~

+ Building of product hardware and software

~

+ Development of software for diagnosis and maintenance (D&M) + Building of hardware for D&M system I---*-+Machines based on flexibility 1---~+ System based on flexibility -~+ Manufacturing system based on flexibility and automation =F~A compromise --~+ New manufacturing systems based Man's on robotical concept --'~flexibility

~ ~

which flexibility is introduced into the domain of product assembly as well.

Hioh level manufacturing systems and hiohly educated workers (113) enable fundamental changes to be made in factory shop floors. Factories were, until the present, the space in which operations were performed with great physical and pyschological effort. Thus interest was lost in the performance of these operations. The new generation of factories assumes the existence of manufacturing systems which will require highly educated workers. This means that the research into the new symbiosis of man and machine will be undertaken here. Namely, it is believed that research in the field of artificial intelligence, and particularly in knowledge engineering, will provide a new redistribution of tasks between man and machines in the domain of intelligence in such a way that man will transfer a part of his intelligence to machines. This has been investigated for nearly thirty years. These investigations point out that we are very far from initial practical results being achieved on these assumptions. Reinvestigation of this concept is being imposed more and more and the development of a new concept which will place man in the control and decision making chain. The problem of communication between parts within a manufacturing system and manto-man and m a n - m a c h i n e communication should be added to this. All this assumes the development of a very complex communication system between parts and between the parts and the whole system which may be organized in a hierarchical or heterarchial way. The high manufacturing level of the equipment and the high level of education of the workers point to the multifunctionality of machines, and the multifunctionality of men as well.

• New product • M a r k e t diffusion

• Machine • productivity • Workers' productivity • Machine worker productivity • Worker-environment productivity

• T i m e e c o n o m y in factory • Time economy of environment

• Durability functions • M a t e r i a l for durability • T e c h n o l o g y for durability • Multifunctionality for d u r a b i l i t y

• Direct w o r k • Indirect work • H u m a n i z a t i o n of work

• Diversity in a family • D i v e r s i t y as a s y m b i o s i s of technology

102

103

104

105

106

107

Z

• Production function complexity • Shape complexity • Complexity o f materials • Dimensions and tolerance

101

Table 3.

+

+

+

+

+

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4

6

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10

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10

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7

7

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5

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6

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8

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8

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1

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2

9

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7

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114 3

6

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2

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3

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115 4

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6

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2

7

3

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7

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116 3

4

+

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+

4

5

2

1

1

4

6

9

20 1

7

13 8

22

Z

71

4

4

6 9 7

12

+

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113 3

+

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7

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1

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112 3

1

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Factory environment and Manufacturing system with high productivity and fast response to and satisfying of market demands (114) assumes highly productive manufacturing methods based on serial production of one product and close interconnection with the product market, the product being manufactured on the market's demand. Here also the strict division of work between the manufacturer and the buyer is removed. However, the established model of the product manufactured at the demand of the buyer has a richer structure in comparison with the model of the product, subject to shopfloor manufacturing capabilities and how the design engineer interprets the product. The basis consists of the user's model which in fact determines the functionality of the product, while the possibility of its manufacture is determined in the factory. The linking of these two models is achieved on the model of the product itself, whose manufacture is supported by comprehensive engineering activity with the planning, design, and conclusively with the preparation of the manufacture of such a product (Fig. 3). This means that the integration of all these functions, the core of which is the model of a product, enables the linking of all functions in question. The manufacturing system is designed to separate machines from men both in space and time (115) through the control and intelligence of the system itself working both autonomously and under a mancontrolled regime. To achieve this, the development of a very strong TOP/MAP communication system is essential with the building of AI elements into the machines and the processes themselves. This will not eliminate man from the entire control and decision making chain, but will include him at the highest level of decision making for the planned work of the manufacturing system. This separation also represents the building of an intercommunication system between certain parts of the manufacturing system and the provision of the coordination and supervision of its work. The question of diagnosis and maintenance of a manufacturing system designed in this way is of particular importance. This implies that elements of self-diagnosis should be designed and installed, together with the design of equipment (machines and robots) for self-maintenance operations, or maintenance with the aid of maintenance robots. Manufacturing system with a high level of flexibility

CIM

• V. R.

MILACIC

221

(116). This characteristic is especially important for manufacturing in which serial productions may consist of one product or a variant when the buyer insists on it. The flexibility of one machine, a group of machines, engineering design or an entire factory with all its activities may be considered. It is particularly important to underline the contradiction between flexibility and automation. Namely, greater flexibility assumes a lower level of automation and contrary to this, greater automation results in lower system flexibility. A new concept of machines should solve this contradiction in the production plane of a manufacturing system, i.e. by passing from the existing relation:

A N-

1 F

to the new relation

A,,~F. One concept is that the configuration of the manufacturing system on the basis of the established production task should be made during machining. Another concept is to build a functional system, for instance, on the basis of kinematic demands for obtaining of desired surfaces, or assembly at different levels of complexity. Here appears the demand for the building of redundant manufacturing systems. The third possible direction is the distribution of flexibility between machine tools, accessories and robots, as manipulation machines.

Input 05. This input is especially important for the introduction of intelligent manufacturing systems into the factory environment and may be considered as logistical support achieved through the control of the entire introduction process with the education of manpower and the linking of the newly designed IMS with the existing parts of the factory structure. More detailed consideration of this input comes out of the framework of this analysis and will be the subject of future research.

Output 01. The definition of the output of this system may be expressed in matrix form as:

I Production pLonning

I Pr°duc' design I

{01} = [IMS]{IO, 11,05}

Process design l

I

[~unctionotity I Producil3iLity] I Productlmodel J Usermodel Fig. 3.

Factorymodel

where IMS is taken as a transformation matrix, while 10, 11, 05 is an input matrix which has been analyzed in detail. The structure of this expression is very complex and an attempt is made here to elaborate it further. I M S transformation matrix. An intelligent manufacturing system may be defined with the logical formula established by the author in a previous paper which is

222

Robotics & Computer-Integrated Manufacturing • Volume 7, Number 3/4, 1990

now expressed as the following matrix form:

Let us show an example how this structure was formalized. If a machine tool is analyzed and the input is 10, i.e. the output member:

F

HI AI I KE !CAD [IMS] = CAM PC M C R

{01}1.7 = [M]{IO} which may be written as

po /

}

[107J

where HI is human intelligence, AI is artifical intelligence, KE is knowledge engineering, CAD is computer-aided product design, CAM is computer-aided manufacturing, PC is computer-aided production planning and control, M are manufacturing machines and accessories, C are computers in all parts of this matrix as a separate IMS unit and R are robots and other robotical systems for performance of different functions in the IMS. Each of the above members of this matrix has a very complex structure so that it is retained here only in the in-depth development of this model, in order to draw out possible combinations of formal connections which are the subject of our investigations. Matrix output-input form and the transformation matrices may be written as: {Output} = [IMS]{Input} so that the output from the system is defined with the following set of relations: {Output} -- [IMS]{10, 11, 05}. The formally written structure of IMS outputs generates connections which are later separately investigated. Each of the members written as a submatrix is made from a sub-submatrix structure through to the definition of primitives.

OI ~, I1_~r- Design -1 theory i~I '

in which the first member is the input matrix, the matrix is:

{101} =

SO SM " DiT

On the other hand, in order to define the transformation matrix linked for the machine, further structuring of our model will be necessary.

1.2. The first decomposition level of the IMS transformation matrix--1 At the first decomposition level we have a global IMS structure consisting of the following substructures: • • • • •

design theory, technologies and machines--fundamental concepts, engineering machines and systems, IMS model, and development of IMS as a laboratory model (Fig. 4).

With the approach shown for IMS zero level the inputs, outputs and transformation matrices for each of these blocks (i.e. substructures) may be defined.

!

OII

n

TechnoLogies ] end / mochines 12J ~.] Engineering ] machines t3I end systems I

it

11

013 It

Model of IMS

--I

014

41 1 ,~

BuiLding IMS

51

015 it

t

tgraduate i

L CeAT J

012

stu-?~

Fig. 4. Program of intelligent manufacturing systems.

O41

IL

it

051

Factory environment

and CIM

The starting point is the statement that for the building of an IMS it is necessary to develop a design theory. The main reason for such a statement should be sought in the fact that it is not possible to design this system on the basis of empirical experience, including interpolation, as in fact here a technological jump (catastrophic penetration) is in question and not development based on an S-model. Various scientific centers in the world are working on the problem of the development of design theory. We have also achieved here considerable results in the development of design theory. However, this is a very complex problem and it is certain that this will be one of the key problems during the next ten years. 2 Technology and machine substructures relate to fundamental research on the discovery of new machines, products and industries. Through mastered knowledge and practical results achieved during the development of civilization, a wealth of knowledge and technologies were collected which should be organized for the purpose of the discovery of new products and systems. We are here particularly interested in building intelligent manufacturing systems. One such analysis has already been completed and systematized.3 Engineering machines and systems are in fact units and structures physically derived from an established concept. Therefore, we deal here with the new generation of machines for the building of an IMS. The model as well as the building of IMS is the result of preceding research work and at the same time a certain evaluation of scientific and technological efforts made within this program.

•

V. R. MILAt~I(~

223

10

II LI desiGeneral gntheoryt 1102 t

011~ 110

. o111

Desiofgn theory , o112 [MS J 01121 1105,,~AE/CAD/CAD t o113

Fig. 5.

• •

computer-aided product design (CAD), and computer-aided manufacturing (CAM).

The structure of our model may be represented as illustrated in Fig. 5. From this model input-output connections may be defined, while retaining the already established definitions and their modifications. The research undertaken until the present pointed to the need to penetrate into other scientific fields such as mathematical topology, theory of automata, cognitive process theory, etc. The inputs 10 and 11 have already been defined for this level. However, only the "transparent" box of general design theory has its own specific structure which gives different output for the same input. It should be mentioned here that input components are not correlated in the same way with the assumed transformation ("transparent box"). The general formula of the functional design system may be defined as;

FS = (FB, PB, SB, p, ~ ) 1.3. Task structure: design theory--1 The further elaboration of this project includes the definition of the demand for design theory. This is at present one of the central scientific fields of research and is also the basis of further development of engineering. The timely recognition of the key scientific area based on cybernetics as a model of interdisciplinary scientific research brought about the awareness of the significance of the changed inter-relations between sciences. The latter is a new dimension in the development of new sciences. It is already obvious today that scientific centers engaged in the development of design theory have been already established. It is not intended here to identify them, but just to state that they exist and to recognize the concept offered by them. The basic characteristics should be recognized as: • •

general design theory, and special design theory (in this case concerned with IMS).

With the development of these segments the conditions will be created for fundamental changes in the domains of: •

the analysis and synthesis of mechanical structures,

showing that it consists of FB which are fundamental knowledge blocks, OB which are operational knowledge blocks, SB which are structural knowledge blocks, and where p: FB x SB~_ 1 -~ SBi is the coupling function and ~ : FB x SB ~ CB is the composition function, after its implementation to the levels of the real world, perceptive world and reflective world. Each of these levels is very complex and it is necessary to build transmission functions to express their connections, which are achieved in upward and downward directions. The models which may be built for relations established in this way may differ subject to their scientific engineering approach. So at the lowest engineering level different simulation models and, at a higher level, deduction models may be observed. It is obvious that the inferences made on deduction models, based on existing knowledge, cannot come out of their framework. Induction reasoning is of particular significance, in case of limited knowledge on the basis of which inferences should be made in a much wider domain. Therefore induction reasoning is especially important for use in combination with an adequate system of learning. This concept is of particular significance for the development of the general design theory. A formalized expression for this block

224

Robotics & Computer-Integrated Manufacturing • Volume 7, Number 3/4, 1990

has the following form:

"General ] {Input = 0111} = design ]{Outputs = 10 ^ 11}. theory J This means that the key part ~s the definition of the general design theory. An extensive effort has already been made in a part of this expression, but further research for the development of the applied design theory is essential. The basic question which is put forward here relates to the possibility of the application of the general design theory to solve specific design problems. In this way we come to the special design theory which relates here to the special design theory of IMS. 2. FACTORY E N V I R O N M E N T AND CIM 2.1. History Human history can be considered through three main projects. The first project is the domestication of animals, started 5000 years ago, which still exists, but with different objectives. The second project is the organization of society and its parts. The third project is the creation of artifacts and particularly of machines. All three projects have been cross-fertilized during human history, generating steady changes expanding and enhancing human capability. The factory can be taken as an example of the crossfertilization of all three projects (for example mining, transportation, manufacturing, etc.). However, the history of factories shows that the combination of organizational and machine projects over almost two centuries has deeply changed factory concepts and influenced the life of the society. Roughly speaking, the phases of factory development are as follows in manufacture: the British concept (first Industrial Revolution), American concept (tolerancing, exchangeability of parts), NC concept and now the CIM concept. All these development stages are classified according to manufacturing technology and manufacturing means, although they are very little related to human nature. Let us start with the definition of a factory according to the Livin9 Webster Encyclopedic Dictionary: A building or collection of buildings used for the manufacture of goods, or colloq.: an institution failing to encourage individual creativity producing only uniformity. The first and the second part of the definition clearly point out that the first concept of factory as a set of buildings and machines exists all the time. The factory was defined as a machine environment, but not as a human environment. As a matter of fact, the human environment was defined by uniformity and discouraged individual creativity. This means that we need a new definition of the factory as a human center. Another important aspect is dealing with the factory environment. Environment has the following

definition in the same dictionary: All the physical, social and cultural factors and conditions influencing the existence or development of an organism or assemblage of organisms; the act of surrounding... Cybernetics should be considered as a science of environments. The classification of environments can be made almost infinitely wide or infinitely narrow. It is primarily defined with the behavior of systems within a specific environment. In addition we can consider an inner and outer environment of a machine or a factory. We can thus divide the entire factory environment into the machine and human environments with broad variability of interfacing of those two parts. Also some FMS components or their features could be related to the entire factory environment. A catastrophe in a very broad sense is any discontinuous transition that occurs when a system can have more than one stable state, or when it can follow more than one stable pathway of change. The catastrophe is the " j u m p " from one state or pathway to another one. Using catastrophe theory, 4 the space is defined by two factors: robot intelligence and factory environment based on the CIM concept as shown in Fig. 6. The factory environment could be defined by levels of flexibility, integration, automation and intelligence. The same parameters are present in machine tools or robots. Each of the selected parameters can be coupled between robot and factory. A similar model could be introduced for machine tool or any hardware or software as a part of CIM. When talking about factory flexibility and robot flexibility there are many differences. The fundamental difference is related to human and machine flexibility and intelligence.

2.2. The contemporary factory There are different concepts of contemporary factory among FMS, CIM and IMS structure. Today the most general and broad logical structure is covered by IMS

(AI ^ CIM (CAD ^ CAM ^ PC A FMS (MT ^ C A R))).

Factory environment(CIM)

I ~High

Low

Fig. 6. Sense and nonsense in robotics.

Factory environment and C I M • V. R. MILAt~I(~

The factory can be defined through the status of knowledge and experience. Comparing the entropy of the existing and the new generation of factory along the lines of knowledge and experience, one could summarize by saying that entropy will change from the minimum to the maximum value (Fig. 8). One proposal along this line has been made--the human-centered CIM concept 5 (Fig. 9). The new framework of this concept is the man-machine system which makes a difference between the allocation of responsibilities and functions including man-machine interfacing.

If this structure is further developed on the basis of artificial intelligence for CIM system we obtain AI

(L6(LISP PROLOG) A KE(Ex) ^ MP (NL A S A V))

where L G (LISP PROLOG) AI are languages and tools; KE (Ex) are knowledge engineering and expert systems: MP (NL A S A V) is machine processing of natural languages and speech and vision. An intelligent manufacturing system can be taken to be a symbiosis of an intelligent programming system (software system) intelligent machine (hardware system) and the software and hardware from the previous generation of machines. The qualitative differences between the existing and new generation of factories (factory of the future) could be expressed by the following paradigm

2.3. Conceptual design of FMS Based on manufacturing requirements and system analyses of the existing production experience and knowledge, conceptual design of FMS covers two parallel lines of activities. The first line deals with equipment (facilities--hardware), and the other deals with the design/manufacturing process (software). The starting and central hardware selection is the machine tool or a set of machine tools and a measuring system. The next step is the selection of a robot or set of robots for material handling. The selection of tooling and accessory equipment can be partly understood as interfacing between machine tool, measuring machine and robot. The second part of the manufacturing chain is related to the transportation of parts and tools. There are two main parts for achieving the transportation function: a transport system and a storage system. The information-communication network has been obtained by a computer control and monitoring system. In order to integrate these two chains each part has a control and an interfacing system as well. The software line covers the CAD/CAM complex, including process planning based on group tech-

{RF} = [T1]{EF} {IF} = [T2]{RF} = [T2][T1]{EF} as shown (Fig. 7).

Real model

{RF} {FF}

Approximate model

[TI] [T2]

Ideal model

IEF} [RF] = [T2] [TI] {EF}

Fig. 7.

Entropy

Knowledge

Experience

Industry

Existing

EEK'-~ min

EE i--"-min

Revitalize

E~K-~ max

EEE--~"rain ENC"" max

225

ENI---- max

Fig. 8.

Organization design

M a n - man aLLocation of responsibilities Organizational structure i

Man-machine allocation of function

=]

I

A

equipment - ., . ~_ Software _ _ Hardware, IMan-machine interface workplace and[ I Application I workplace I ~ software Environment ~ ~1

z

x

Hardware and I environmental [ ergonomics

Fig. 9.

J

• , : Information flow

dab design

Software ergonomics

226

Robotics & Computer-IntegratedManufacturing t Volume 7, Number 3/4, 1990

IO, X,Y,*I SS,,: I0,0,0,0 I X3

~I

q2 (f,,,)Y.

IR States Robot xl

X2 x3 x4

MT

Code I

Yl Y2

---_-=

/

-I

Y3 Y4

I r'l

-/

I

L,

I-~

Fig. 12. Machine tool structure.

%,.J k . J

Manufacturing task Parts store

AGV

Robot

/

/

Design requirements

Machine

/ /

/

/

P,

I

0

I I

l

2

P2

I 3

;idtte(~ eoC~or '

Fig. 10.

Fig. 13. nology and producibility aspects. The software line generates the basic requirements for hardware definition. It is necessary to create an interface between these two blocks and understand the problem as a multidimensional one. In addition the whole FMS structure is rather complex. Here the method and models are proposed on how to build the structure and interfacing substructures into integrated FMS. Let us take an example of an FMS which consists of a machine tool (MT), robot (R) and automated guided vehicle (AGV) (Fig. 10). A complex graph shows the dynamic coupling between MT--* R and R--, AGV. This coupling can be considered on the manufacturing task level as well as on the conceptual design level (basically on the functional level).

p(I,O):(O,X,Y,W) x ( 0 , 0 , 0 , 0 ) ~(O,O,O,W) p(I,I]:(O,X,Y,W) x (O,O,~,W)~(O,O,Y,W) p(i,2):(O,X,Y,W) x (O,O,Y,W) ~('O,O,Y,W) p(I,3):(O,X,Y,W] x (X,O,Y,W} ~ ( X , O , Y , W )

p(j,p-I}

:

I KII KZl /~31 K41

n(I}

MT=

Fig. 11.

Ios,c,d, b2}

KI2 K22 K'3Z K42

KI3 K23 K33 /('45

KI4 /(2a I K34 K44

~101~

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~oi

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Fig. 14(a).

Factory environment and

CIM• V.R.MILACIC

The machine tool structure can be defined manufacturing process planning inputs and outputs

machine is given in Fig. 14. The same graph is used for robot design. The structural expression for the robot is:

MT = {as, c, d, b2}

R, = {X, Y, Z, A, B, C}.

determined with the following production rules: WP ~

227

The last element is the AGV whose structural expression is

ala2a3a,,asMT

MT ~ cWP

AGV, = {0, X, Y, Z, A, B, C},

MT --* dTTS (Fig. 11).

All three subsystems are coupled into an FMC structural expression as

In order to satisfy manufacturing requirements the functional structure of machine tool is given by structural expression:

FMC, = {MT,, R,, AGV,}. By introducing thc coupling function inside onc subsystem and also among subsystems one can obtain an adequate F M C structure defined with the set of manufacturing tasks.

MT s = {B, X, O, W, Y,/Ch} according to Fig. 12. A metagraph for the conceptual design of the

PRR:

{X,Y,Z,B,C} Matrix

XYZBC XYZC XYBCZ

YXZBC

YXZC B

B

YXBZC YXBCZ

XYCBZ

C

B

ZXYBC ZXYC B ZXB YC ZXBC Y

• . .

120

Y ~ ] C(5)

,

-Y!2~---L--~

B(41

IXYZBC

XZYBC]

Z ( 2 ~

I x YZCB

)

XZYCBI

C(5)

/~X(I)

" -

Z(2) ~

C(5} XYBZC

XZBYCI

C(4) Y(2)

8(3)

~L~

C(41 z(5)

xzBcYI Fig. 14(b). Robot structure.

T

Y(5)

228

Robotics & Computer-IntegratedManufacturing $ Volume 7, Number 3/4, 1990 PRAGv: IO, X , Y , Z , A , 8 , C }

OX

OY

(o, 8, §)

(O,X, (0, X , (0, X ,

p ( I , 2 , 3) o p ( I , 2 , 3), p(I , 2 , 3) 2

(0, X , Y, Z , A , B , C (0, X, Y, Z , A , 8 , C (0, X , Y, Z , A , B, C

x (0, O, O) ~ (0, O, O) x (0, 8, 6 ) ~ (6, x, 6) x (0, X, 0 ) ~ ( 0 , X, Y)

p ( l , 7 , 7}o p(l, 7 ,7), p ( l , 7 , 7) z

(0, X , Y, Z , A (0, X , Y, Z , ~ (O,X, Y,Z,A

x (0, O, O ) ~ ( 0 , O, O) x (0, O, O) ~ (0, C, O) x (6, C, 5 ) ~ ( 0 , C, C}

__

OXX

Y, Z , . ~ , 8 , C ) Y, Z , A , B , C) Y, Z , A ; B , C )

x (0, 6, < 3 ) ~ x (0, O, O } ~ x (~), X, 0 ) ~

p(I, 2 , 2) 0 p(I , 2 , 2), p( I , 2 , 2 )2

OYX

B, C B, C B, C

OZX

OAX

OBX

( O , X , O) (0, X , X)

OCX 1

/ i

- OXY

OYY

OZY

OAY

OBY

OCY

I

OXZ

OYZ

OZZ

OAZ

OBZ

OCZ

OXA

OY~

OZA

OAA

OB~

OCA

OXB

OYB

02"8

OAB

OBB

OCB

i

OXC

OYC

OZC

OAC

OBC

OCC

~

c

Fig. 14(e). AGV structure.

2.4. Structural pattern recognition of FMS--instead of a conclusion It is evident that the subject of the factory environment and, more specifically, intelligent manufacturing systems is very broad and complex. However, some elements are offered here to build a framework for intensive research. One of the most important aspects of FMS is to define a basic structure. An example is given here of structuring the three main parts of an FMS" machine tool, robot and AGV. All three hardware units are defined by pattern recognition blocks of knowledge and structural blocks of knowledge. The next step is to develop a method of building

operating blocks of knowledge, as well as coupling and composition functions. REFERENCES

1. Mila~ir, R. V.: Intelligence as an Important Feature of CIM, IMS-L Amsterdam, Elsevier, 1988. 2. Mila~ir, R. V.: Manufacturing Systems Design Theory. Mechanical Engineering Faculty, Beograd University, Beograd, 1987. 3. Mila~ir, R. V. with associates: Intelligent manufacturing systems. Research Project Report No. 107, Beograd 1989. 4. Woodcock, A. and Davis, M.: Catastrophe Theory. Harmondsworth, Penguin, 1978. 5. Slatter, R. R. et al.: A human centred approach to the design of advanced manufacturing systems. Ann. CIRP 38: 461-464, 1989.