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Scientific Problems of CIM and Ways for their Solution
( : f)p~right
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11" :\( : Informatioll (:oIlII"ClI Prohlelll"; SU/,{L!!, l'SSR, l~t~l)
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SCIENTIFIC PROBLEMS OF CIM AND WA VS FOR THEIR SOLUTION Y. M. Solomentsev .\lOSCOll' ,\l(lchillt Toul (Il1d SII/all Tool IlIstitutt ISTAXKIX) , lv1oscolL', USSR
Abstract. Introduction of computer integrated manufactures \ elM) makes one of the basic ways of development of manufacturing processes. Construction of CIM is a complicated problem. Such industrial system will be made up of CNC machine tools \ as the main group of operating machines) , automatic transport systems, loading/unloading robots, automatic storage facilities as well as a distributed network of computer-based control system of different levels from microprocessors to large-size computers and other components of CIM: technology with required quality control, tooling, information and measuring, CAD software and hardware, economic management. Keywords. Computer integrated manufacture; flexible manufacturing system; computer-aided design; adaptive control; manufacturing processes. Il~TRODUCTION
Introduction of CIM with labour and energy saving processes marks one of the basic ways of development of mechanical engineering tOday. The utmost results, at that, are obtained by introduction of CIM which comprises all industrial processes such as production of blanks, thermal treatment, machining and assembly of components.
~IT_E_ ' C_H_N_O_L_O_G_I_C_A_L______~k DESIGN IBLANC-PRODUCTION COMPUTER INTEGRATED 11ANUFACTU .m
STORAGE In its turn , each industrial process requires specific package of automatic equipment which is selected on the basis of economic and technical feasibility studies with due regard to the actual industrial conditions. For example, depending on the available industrial process the following automated complexes can be used for part manufacturing, i.e. module, cell, flexible manufacturing system ( FMS ), automated production line, unmanned shops, unmanned factories.
ICONTROL INFORHATION AND lEASURIl~G
RELIABILITY AND DIAGNOSTICS SOFTHAKE HARDWARE ECONOMIC MANAGEMENT
Demand for a wide range of high-quality end products, multi-nomenclature batch manufacturing, the necessity to suit the arising requirements of the society, manpower deficiency and high labour costs place the development of CHI amongst the most urgent problems of today. Construction of CIM is a complicated problem. Such industrial system will be made up of CNC machine tools \ as the main group of operating machines ), automatic transport systems, loading / unloading robots, automatic storage facilities as well as a large network of computer-based control system of different levels ( from microprocessors to large-size computers and other components of CD1 , fig. 1.
Fig. 1. Components of CIM. THE I~IN SCIENTIFIC ru,D TECHNOLOGICAL PROBL£MS OF CIf.1 Technological problems will include: - stable production of hign-quality parts in CIl1 including the stages of mounting, setting-up and machining; - theoretical groundS for the development of CAPP systems; - designing tooling systems and pallet fixtures; - computer-aided development of NC-programming.
6
Yu. 1\1. SuiOlllelltse\
Design problems will include: -formal description of a machine to be produced; - methods of construction and optimisation of the machine design; - computer-aided design of components with the view to getting blueprints. The problems relating to the tooling aids were mentioned alongside the technological ones, but taking into account their importance it is necessary to distinguish their main research trends: - development of CAD systems for cutting tools; - development of CAD systems for an auxiliary tool; - development of new tool construction and modification of the existing cutting tool on the basis of its utilization in CAM systems; that is improvement of its wear resistance, reliability, flexibility; - research on the problem of improvement of operating conditions for cutting tool, such as selection of optimal cutting modes, development of diagnostic techniques; - development and arrangement of automatic transport systems, automatic tool change systems. An information and measuring system implies the development of measuring, automatic checkout and pattern recognition system. As a matter of fact the information and measuring system is a problem of measuring information theory of CN1 that is carried out in three directions: - principles of building up the information and measuring system; - hardware and software of the information and measuring system; -checking out all the parts.
A highly important but less investigated problem is the creation and use of transport system, intermediate storage and stocking of transferred parts and components. The following scientific trends are urgent here: - creation of a classifier for parts and manufacturing systems that allow to carry out the development of unified containers for transportation of a group of parts ( pallets, magazines, pans ); - development of formula-like representations and variants of automatic and storage transportation facilities as a whole; - development of computer aided selection system for transportation. and storage. Special attention in transportation system is paid to the development of basic scientific design fundamentals, creation and using industrial robots and robotic systems for different purposes that correspond constructive, technological and economical requirements. Economic facilities shall involve: - development of criteria to optimize the production structure of an enterprise, economic justification of computer-aided system sphere of application, methodics of pre-design study; - developing a system for the optimisation of structure and operation of a CIM; - economic problems of using separate elements of CIM.
Software for FMS control includes system and specific software, operational system and applied software. First consists of: - p)anning a computing process for FMS control; - development of effective operating systems for microprocessors on the basis of their orientation problem; - development of other special systems and design methodics of technologically oriented data base. Applied software system includes tne development of applying computering mathematical methods to the solution of specific production tasks. It's impossible to use ~rlS witnout tne ~e velopment of modern control hardware tnat comprisesNC systems, microprocessors anu controllers, ILlotors of uifferent Kin~s and for various purposes. In a~~ition reliability and diagnostics of tne system are the most important problems. 1'oday nearly the greatest number of problEmS are connected with software and hardware FMS control. Hardware FMS control must be organized as local computers network, but with peculiarities which follow from control problems of technological processes in real time. Software local computers network of FMS control supports network functions, creates base for space distribution of separate control problem~ offers mechanism for coordination of the above problems, conducts informational statistic and diagnostic models of FMS, provides information service, organizes external interaction with global problems of general scale. Important scientific problems of software and hardware control include: - providing network compatability of potentially non-compatible programs software and hardware based on deep standartization taking into account FMS peculiarity; - optimisation of set, range, functional possibilities and architecture of separate control systems united in FMS; - creation of instrumental means which are able to genegate model of multi-functional controlled technological process as FMS object; - creation of instrumental means which are able to generate software of FMS generally according to technical task to a new project; -development of an intellectual FMS control system, aimed at making not ordinary decisions dealing with computer aidea finish work of software, diagnostics, planning computer control process, giving reco~nen dations for system reconfiguration etc. Flexible CAM will demana essential reauction of time and increasing the quality of designing and technological development of parts. To reaCh it one must widely use different CAD software and hardware practically in all the fields of machinery. Besides the following problems must be solved: - development of the designing theory of parts in connection with the specific properties and condition of manufacturing
Scit' llt ific prohlullS of (: 1\ 1
system; - fundamental investigation that will de fine their physical, technical, economical parameters to receive their mathematical model . THE BAIN STAGES IN DESIGlUNG FHS High-quality output required a most tho rough analysis of manufacturing methods involved to produce articles , for they are the most important and crucial stage of production . To get a clearer view of the role of te chnological aspects in the development and functioning of FMS it is necessary , first of all , to examine the main stages in designing such systems, which are to be based on utilization of computers and CAD mainly due to the multiple variance of problems solved. Pre - design study. While designing FMS it is necessary to perform a so-called predesign study. This stage starts with the analysis of production process and it is desirable to begin the study from " the top" , since the designed FMS is to fit well structurally into the system of production. This analysis makes it possible to reveal the nomenclature , quantity , num ber of parts in batch and structural-manu facturing properties of the parts in case of mach i ning . To prepare the needed and sufficient bank of initial data for the purposes of des i g ning it is important to classify the ar t i cles and parts on the basis of the ir designated purpose. In this case it is possible to systematize the pre - design s t ages , carry out unification and stan dartization , reduce the nomenc l ature of the cutting tool used , employ progressive processes. Of great re l evance it is to make the right cho i ce of the production methods and to give preference to progressive technologies basea both on new physical effects and on the complex use of the already existing methods of machining . Under these circumstances a very important role is attributed to the so - called " bank of phy sical effects " utilization of which is to enable automatic generation of new produc t i on me t hods. Then comes designing of " elementary " product i on methods which involves representa tion of parts as a set of standar d e l e ments of form \ for examp l e, smooth hole , stepwi se hole , th r eaded hole , taped hole etc ) and assignment of an " elementary route " for any standard element , that is sequence of operations ( types of machi ning , plans of machining). It is obv i ous that performance of this procedure requires development of spec i fic CAPP system for an elementary level . Lists of elemen tary routes make up the initial mate ri al to group piece - operations accord i ng to de sign - techno l ogical signs. The p r esent day p r oduction proce s s of ma chine - building is subdivided by character into mass , batch and unit depending on the program of part production , nomenclature , demensions etc . Since it is impossible to
7
draw a clear line between different types of production, and taking into account that certain technological operations in machining different surfaces of one or several parts may considerably vary in time , and that there is a possibility to comb i ne partially technological opera ti ons of machining of several parts one shouldn ' t treat in a unique manne r a kind of pro duction as a whole . Production structure by its technological functiona l dependancies may contain ele ments of different kinds of production. That is why it is necessary to make models of production types and criteria of opti mality as eary as at the pre - design stage. Unde r a kind of product i on we mean the type of equipment used and forms of l?ro duction menagement . Then comes representation of " elementary " technology on different types of equip ment , arrangement of operations , making up of the equipment operation schedule \ if needed ) , selection of kinds of p r o duction for differen t g r oups of part ope r ations. Thus at the stage of pre - design research technological requirements to FMS sect ions are defined and links between separate manufacturing subdivisions of the enterprise are established. FMS designing. The first thing at this stage is to know what elements FMS can consist of. I t is necessary to perform forming and a n alys i s of element mode l s of FMS . These elements are: machine tools, pallets , transport , warehouses. The model of the elements must contain a set of formal parameters needed for an aaequate description of corresponding technologi cal functions , namely a model must des c r ibe possibilities of an element. For example , a machine tool may be characte rized by the size of a pallet , the num ber of coordinates , the accuracy of ma chining , the capacity of a tool magazine etc. The mode l s of separate elements and the model of possibl e interaction bet ween them give a common model of the whole complex system , that is FMS. He can represent here s t ructural , dynamic , simu l ation, information etc mode l s . The structural model of FMS l the composition of its basic and auxiliary technologica l equipment ) allows to define a criterion or a system of cri t eria of its functio ning optimum, to build mach i ning group technology and contro l system having i n mind a schedule. The task may be formu lated i n such a way: there is a set of pa rt batches and a set of plans of eve r y part machining. It is necessary to find such a sequence of machining of part ba tches and machining plans of eve r y part that the g i ven set of pa r ts shou l d go through FMS for as short a t i me as pos sible . This task may be r eferred to as a complete task of the class " ,, " and has no effective algorithms for solving. In troducting some r estricting heuristics we may suggest some models of contr o l which give a rathe r good schedu l e of the equipment work at the stage of des i gn i ng. The task of optimum control of FMS being a dynami c one presents certain inte r es t . As a result of failure of any element of
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FMS or arrival of extra urgent parts the schedule is disrupted. The task is to c l ear off the disturbance or to replan the work of FMS in an optimum way. Repre senting FMS as a technicai system or as an algebra system \ that is : A, P , 0 where A is a set of elements, ? - a set of relations, 0 - a set of operations) we can enumerate all possible structures of FMS using combinator methods; and using some definite restrictions we can get ad missable structures of FMS. Introducting a criterion of optimum allows to put i n order the obtained structures and to choose the best one. It should be noted that the choice of a structure, composition of the basic and auxiliary equipment is at the l evel of a technical suggestion and first study design . The errors at this le vel usually lead to irrepairable or hard ly repairable consequences . Variety of structures at their generation may seem very great . It is defined by a number of components which FMS is composed of . But unfortunately at present we don't possess a large enough number of such components. If the possibility of the technological equipment is an active limitation of FMS , there arises a problem of giving a new technical task and designing a new and more suitable equipment . Designing of the technological processes . It includes CAPP, NC programming and sys tem of tooling. perhaps , one of the main problems of CA?? and NC - programming is the problem of encoding geometrical informa tion about a part. Effective systems of encoding prismatic parts haven't been de veloped yet. 'Time of encoding becomes comparable with the time of describing a te chnological process in the input language of l~C - programming. Tooling system connected with the tecnno logy of machining identical parts has the fo l lowing main aspects : tool set-up, tool making up into a set for machining a batch of parts , tool condition diagnost i cs in the process of its maintenance . Adaptive control . The demand for high flexibility of automatic systems, the provi sion for the required part quality in the unmanned machining mode raised in the first p l ace the questions of adaptive control of techno l og i cal processes. ~he Soviet school of production eng i nee r s set up and headed by prof . Balakshin pioneered the develop ment of theoretical princip l es of adaptive control and the first machine tools with adaptive systems. All - round researches in the fie l d of adapt i ve control have been carried out in the Moscow Machine Tool and Small Tool Institute. Since the demand for providing the requi red part quality form the basis of any te chnological process , the adaptive control systems by means of elastic deformation cont r ol have been developed on the first stage . In these systems the accuracy and working productivity have been increased by several times at the expense of chan ging working conditions or by means of forc i able aimed displacement of seperate com ponents of the technological system . At present machine tools including clC machi -
nes are equipped with such control sys tems. Besides advantages men t ionea above , the use of such adaptive control systems a ll ow to increase considerably the reliabi l ity of the eqUipment and the tools, that is to say , to avoid their breakage in the case of emergency. It is achieved by means of the suitable control in the course of adjusting or stopp i ng the te chnological process indicating certain defects. The reseach shows that the efficiency of the machining process mainly depends on the proper maintenance of tne cutting tool. The task of optimal tool use by means of adaptive control has been set and solved . As a result , the tool l ife has been increased by 1.5 - L times , particu la r ly when machining special hardworking materials . One of the main reasons of this effect is that the positive feedback of tne cutting process itself is broken off when controlling . With the purpose of increasing mach i ne tool module and FMS flexibility, the systems of adaptive control by setting up and resetting up have been developed . Tne experimental research showed that the setup accuracy can be achieved within some micrometrs , as a result the size accuracy increases by 1 . 6 - 1.6 times . The time spent on setting up and resetting up is considerably decreased . It is proved tnat the use of adaptive systems allow to in crease the initial productivity of FMS by 2 - 3 times. Thus when solving the same problems one can use a smaller amount of equipment . Integrated CAD/CAM systems . 'l'nese systems r equire hardware and software development , link channels and common data base which one can eas i ly get to from any production stage. The computer of various classes from mic roprocessors to large computers form the hardware of CAD/CN1 systems . For effective use these computers are integrated in the network ( fig . 2 ) . ~his provides integra t i on of design , production process p l an ning , manufacturing and con t rol systems. At the same t ime it al l ows to increase the re li abi l ity of computers. I n the sof t ware two relatively independent pa r ts are distinguished : invariable which depends on the design ob j ect to a l ittle extent a nd a specific one . The i nvariable pa r t of sof t ware includes control p r og r am, data base cont r o l system , the programs of computer graphics , document system programs. The design p r ocedures referring to a defi nite design and manufacturing object form a specif i c part and corresponding data bases. CONCLUSION The given approach has been put i nto tne base of all - round scient i fic subject development on the creat i on of CIn by means of CAD a n d fully justified itself .
Scielllific proble ms of C l \1
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Fig. 2 . Hardware of the STANKIN institute compu t er network.
©
11" :\( : Informatioll (:oIlII"ClI Prohlelll"; SU/,{L!!, l'SSR, l~t~l)
ill
\bllllbct llrill,~ T('{'hllf)lf)g~,
SCIENTIFIC PROBLEMS OF CIM AND WA VS FOR THEIR SOLUTION Y. M. Solomentsev .\lOSCOll' ,\l(lchillt Toul (Il1d SII/all Tool IlIstitutt ISTAXKIX) , lv1oscolL', USSR
Abstract. Introduction of computer integrated manufactures \ elM) makes one of the basic ways of development of manufacturing processes. Construction of CIM is a complicated problem. Such industrial system will be made up of CNC machine tools \ as the main group of operating machines) , automatic transport systems, loading/unloading robots, automatic storage facilities as well as a distributed network of computer-based control system of different levels from microprocessors to large-size computers and other components of CIM: technology with required quality control, tooling, information and measuring, CAD software and hardware, economic management. Keywords. Computer integrated manufacture; flexible manufacturing system; computer-aided design; adaptive control; manufacturing processes. Il~TRODUCTION
Introduction of CIM with labour and energy saving processes marks one of the basic ways of development of mechanical engineering tOday. The utmost results, at that, are obtained by introduction of CIM which comprises all industrial processes such as production of blanks, thermal treatment, machining and assembly of components.
~IT_E_ ' C_H_N_O_L_O_G_I_C_A_L______~k DESIGN IBLANC-PRODUCTION COMPUTER INTEGRATED 11ANUFACTU .m
STORAGE In its turn , each industrial process requires specific package of automatic equipment which is selected on the basis of economic and technical feasibility studies with due regard to the actual industrial conditions. For example, depending on the available industrial process the following automated complexes can be used for part manufacturing, i.e. module, cell, flexible manufacturing system ( FMS ), automated production line, unmanned shops, unmanned factories.
ICONTROL INFORHATION AND lEASURIl~G
RELIABILITY AND DIAGNOSTICS SOFTHAKE HARDWARE ECONOMIC MANAGEMENT
Demand for a wide range of high-quality end products, multi-nomenclature batch manufacturing, the necessity to suit the arising requirements of the society, manpower deficiency and high labour costs place the development of CHI amongst the most urgent problems of today. Construction of CIM is a complicated problem. Such industrial system will be made up of CNC machine tools \ as the main group of operating machines ), automatic transport systems, loading / unloading robots, automatic storage facilities as well as a large network of computer-based control system of different levels ( from microprocessors to large-size computers and other components of CD1 , fig. 1.
Fig. 1. Components of CIM. THE I~IN SCIENTIFIC ru,D TECHNOLOGICAL PROBL£MS OF CIf.1 Technological problems will include: - stable production of hign-quality parts in CIl1 including the stages of mounting, setting-up and machining; - theoretical groundS for the development of CAPP systems; - designing tooling systems and pallet fixtures; - computer-aided development of NC-programming.
6
Yu. 1\1. SuiOlllelltse\
Design problems will include: -formal description of a machine to be produced; - methods of construction and optimisation of the machine design; - computer-aided design of components with the view to getting blueprints. The problems relating to the tooling aids were mentioned alongside the technological ones, but taking into account their importance it is necessary to distinguish their main research trends: - development of CAD systems for cutting tools; - development of CAD systems for an auxiliary tool; - development of new tool construction and modification of the existing cutting tool on the basis of its utilization in CAM systems; that is improvement of its wear resistance, reliability, flexibility; - research on the problem of improvement of operating conditions for cutting tool, such as selection of optimal cutting modes, development of diagnostic techniques; - development and arrangement of automatic transport systems, automatic tool change systems. An information and measuring system implies the development of measuring, automatic checkout and pattern recognition system. As a matter of fact the information and measuring system is a problem of measuring information theory of CN1 that is carried out in three directions: - principles of building up the information and measuring system; - hardware and software of the information and measuring system; -checking out all the parts.
A highly important but less investigated problem is the creation and use of transport system, intermediate storage and stocking of transferred parts and components. The following scientific trends are urgent here: - creation of a classifier for parts and manufacturing systems that allow to carry out the development of unified containers for transportation of a group of parts ( pallets, magazines, pans ); - development of formula-like representations and variants of automatic and storage transportation facilities as a whole; - development of computer aided selection system for transportation. and storage. Special attention in transportation system is paid to the development of basic scientific design fundamentals, creation and using industrial robots and robotic systems for different purposes that correspond constructive, technological and economical requirements. Economic facilities shall involve: - development of criteria to optimize the production structure of an enterprise, economic justification of computer-aided system sphere of application, methodics of pre-design study; - developing a system for the optimisation of structure and operation of a CIM; - economic problems of using separate elements of CIM.
Software for FMS control includes system and specific software, operational system and applied software. First consists of: - p)anning a computing process for FMS control; - development of effective operating systems for microprocessors on the basis of their orientation problem; - development of other special systems and design methodics of technologically oriented data base. Applied software system includes tne development of applying computering mathematical methods to the solution of specific production tasks. It's impossible to use ~rlS witnout tne ~e velopment of modern control hardware tnat comprisesNC systems, microprocessors anu controllers, ILlotors of uifferent Kin~s and for various purposes. In a~~ition reliability and diagnostics of tne system are the most important problems. 1'oday nearly the greatest number of problEmS are connected with software and hardware FMS control. Hardware FMS control must be organized as local computers network, but with peculiarities which follow from control problems of technological processes in real time. Software local computers network of FMS control supports network functions, creates base for space distribution of separate control problem~ offers mechanism for coordination of the above problems, conducts informational statistic and diagnostic models of FMS, provides information service, organizes external interaction with global problems of general scale. Important scientific problems of software and hardware control include: - providing network compatability of potentially non-compatible programs software and hardware based on deep standartization taking into account FMS peculiarity; - optimisation of set, range, functional possibilities and architecture of separate control systems united in FMS; - creation of instrumental means which are able to genegate model of multi-functional controlled technological process as FMS object; - creation of instrumental means which are able to generate software of FMS generally according to technical task to a new project; -development of an intellectual FMS control system, aimed at making not ordinary decisions dealing with computer aidea finish work of software, diagnostics, planning computer control process, giving reco~nen dations for system reconfiguration etc. Flexible CAM will demana essential reauction of time and increasing the quality of designing and technological development of parts. To reaCh it one must widely use different CAD software and hardware practically in all the fields of machinery. Besides the following problems must be solved: - development of the designing theory of parts in connection with the specific properties and condition of manufacturing
Scit' llt ific prohlullS of (: 1\ 1
system; - fundamental investigation that will de fine their physical, technical, economical parameters to receive their mathematical model . THE BAIN STAGES IN DESIGlUNG FHS High-quality output required a most tho rough analysis of manufacturing methods involved to produce articles , for they are the most important and crucial stage of production . To get a clearer view of the role of te chnological aspects in the development and functioning of FMS it is necessary , first of all , to examine the main stages in designing such systems, which are to be based on utilization of computers and CAD mainly due to the multiple variance of problems solved. Pre - design study. While designing FMS it is necessary to perform a so-called predesign study. This stage starts with the analysis of production process and it is desirable to begin the study from " the top" , since the designed FMS is to fit well structurally into the system of production. This analysis makes it possible to reveal the nomenclature , quantity , num ber of parts in batch and structural-manu facturing properties of the parts in case of mach i ning . To prepare the needed and sufficient bank of initial data for the purposes of des i g ning it is important to classify the ar t i cles and parts on the basis of the ir designated purpose. In this case it is possible to systematize the pre - design s t ages , carry out unification and stan dartization , reduce the nomenc l ature of the cutting tool used , employ progressive processes. Of great re l evance it is to make the right cho i ce of the production methods and to give preference to progressive technologies basea both on new physical effects and on the complex use of the already existing methods of machining . Under these circumstances a very important role is attributed to the so - called " bank of phy sical effects " utilization of which is to enable automatic generation of new produc t i on me t hods. Then comes designing of " elementary " product i on methods which involves representa tion of parts as a set of standar d e l e ments of form \ for examp l e, smooth hole , stepwi se hole , th r eaded hole , taped hole etc ) and assignment of an " elementary route " for any standard element , that is sequence of operations ( types of machi ning , plans of machining). It is obv i ous that performance of this procedure requires development of spec i fic CAPP system for an elementary level . Lists of elemen tary routes make up the initial mate ri al to group piece - operations accord i ng to de sign - techno l ogical signs. The p r esent day p r oduction proce s s of ma chine - building is subdivided by character into mass , batch and unit depending on the program of part production , nomenclature , demensions etc . Since it is impossible to
7
draw a clear line between different types of production, and taking into account that certain technological operations in machining different surfaces of one or several parts may considerably vary in time , and that there is a possibility to comb i ne partially technological opera ti ons of machining of several parts one shouldn ' t treat in a unique manne r a kind of pro duction as a whole . Production structure by its technological functiona l dependancies may contain ele ments of different kinds of production. That is why it is necessary to make models of production types and criteria of opti mality as eary as at the pre - design stage. Unde r a kind of product i on we mean the type of equipment used and forms of l?ro duction menagement . Then comes representation of " elementary " technology on different types of equip ment , arrangement of operations , making up of the equipment operation schedule \ if needed ) , selection of kinds of p r o duction for differen t g r oups of part ope r ations. Thus at the stage of pre - design research technological requirements to FMS sect ions are defined and links between separate manufacturing subdivisions of the enterprise are established. FMS designing. The first thing at this stage is to know what elements FMS can consist of. I t is necessary to perform forming and a n alys i s of element mode l s of FMS . These elements are: machine tools, pallets , transport , warehouses. The model of the elements must contain a set of formal parameters needed for an aaequate description of corresponding technologi cal functions , namely a model must des c r ibe possibilities of an element. For example , a machine tool may be characte rized by the size of a pallet , the num ber of coordinates , the accuracy of ma chining , the capacity of a tool magazine etc. The mode l s of separate elements and the model of possibl e interaction bet ween them give a common model of the whole complex system , that is FMS. He can represent here s t ructural , dynamic , simu l ation, information etc mode l s . The structural model of FMS l the composition of its basic and auxiliary technologica l equipment ) allows to define a criterion or a system of cri t eria of its functio ning optimum, to build mach i ning group technology and contro l system having i n mind a schedule. The task may be formu lated i n such a way: there is a set of pa rt batches and a set of plans of eve r y part machining. It is necessary to find such a sequence of machining of part ba tches and machining plans of eve r y part that the g i ven set of pa r ts shou l d go through FMS for as short a t i me as pos sible . This task may be r eferred to as a complete task of the class " ,, " and has no effective algorithms for solving. In troducting some r estricting heuristics we may suggest some models of contr o l which give a rathe r good schedu l e of the equipment work at the stage of des i gn i ng. The task of optimum control of FMS being a dynami c one presents certain inte r es t . As a result of failure of any element of
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FMS or arrival of extra urgent parts the schedule is disrupted. The task is to c l ear off the disturbance or to replan the work of FMS in an optimum way. Repre senting FMS as a technicai system or as an algebra system \ that is : A, P , 0 where A is a set of elements, ? - a set of relations, 0 - a set of operations) we can enumerate all possible structures of FMS using combinator methods; and using some definite restrictions we can get ad missable structures of FMS. Introducting a criterion of optimum allows to put i n order the obtained structures and to choose the best one. It should be noted that the choice of a structure, composition of the basic and auxiliary equipment is at the l evel of a technical suggestion and first study design . The errors at this le vel usually lead to irrepairable or hard ly repairable consequences . Variety of structures at their generation may seem very great . It is defined by a number of components which FMS is composed of . But unfortunately at present we don't possess a large enough number of such components. If the possibility of the technological equipment is an active limitation of FMS , there arises a problem of giving a new technical task and designing a new and more suitable equipment . Designing of the technological processes . It includes CAPP, NC programming and sys tem of tooling. perhaps , one of the main problems of CA?? and NC - programming is the problem of encoding geometrical informa tion about a part. Effective systems of encoding prismatic parts haven't been de veloped yet. 'Time of encoding becomes comparable with the time of describing a te chnological process in the input language of l~C - programming. Tooling system connected with the tecnno logy of machining identical parts has the fo l lowing main aspects : tool set-up, tool making up into a set for machining a batch of parts , tool condition diagnost i cs in the process of its maintenance . Adaptive control . The demand for high flexibility of automatic systems, the provi sion for the required part quality in the unmanned machining mode raised in the first p l ace the questions of adaptive control of techno l og i cal processes. ~he Soviet school of production eng i nee r s set up and headed by prof . Balakshin pioneered the develop ment of theoretical princip l es of adaptive control and the first machine tools with adaptive systems. All - round researches in the fie l d of adapt i ve control have been carried out in the Moscow Machine Tool and Small Tool Institute. Since the demand for providing the requi red part quality form the basis of any te chnological process , the adaptive control systems by means of elastic deformation cont r ol have been developed on the first stage . In these systems the accuracy and working productivity have been increased by several times at the expense of chan ging working conditions or by means of forc i able aimed displacement of seperate com ponents of the technological system . At present machine tools including clC machi -
nes are equipped with such control sys tems. Besides advantages men t ionea above , the use of such adaptive control systems a ll ow to increase considerably the reliabi l ity of the eqUipment and the tools, that is to say , to avoid their breakage in the case of emergency. It is achieved by means of the suitable control in the course of adjusting or stopp i ng the te chnological process indicating certain defects. The reseach shows that the efficiency of the machining process mainly depends on the proper maintenance of tne cutting tool. The task of optimal tool use by means of adaptive control has been set and solved . As a result , the tool l ife has been increased by 1.5 - L times , particu la r ly when machining special hardworking materials . One of the main reasons of this effect is that the positive feedback of tne cutting process itself is broken off when controlling . With the purpose of increasing mach i ne tool module and FMS flexibility, the systems of adaptive control by setting up and resetting up have been developed . Tne experimental research showed that the setup accuracy can be achieved within some micrometrs , as a result the size accuracy increases by 1 . 6 - 1.6 times . The time spent on setting up and resetting up is considerably decreased . It is proved tnat the use of adaptive systems allow to in crease the initial productivity of FMS by 2 - 3 times. Thus when solving the same problems one can use a smaller amount of equipment . Integrated CAD/CAM systems . 'l'nese systems r equire hardware and software development , link channels and common data base which one can eas i ly get to from any production stage. The computer of various classes from mic roprocessors to large computers form the hardware of CAD/CN1 systems . For effective use these computers are integrated in the network ( fig . 2 ) . ~his provides integra t i on of design , production process p l an ning , manufacturing and con t rol systems. At the same t ime it al l ows to increase the re li abi l ity of computers. I n the sof t ware two relatively independent pa r ts are distinguished : invariable which depends on the design ob j ect to a l ittle extent a nd a specific one . The i nvariable pa r t of sof t ware includes control p r og r am, data base cont r o l system , the programs of computer graphics , document system programs. The design p r ocedures referring to a defi nite design and manufacturing object form a specif i c part and corresponding data bases. CONCLUSION The given approach has been put i nto tne base of all - round scient i fic subject development on the creat i on of CIn by means of CAD a n d fully justified itself .
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