Nimble production unit builds the research of modular technology

This OOTPN Approach Possesses The Characteristics Of Object-oriented Methods And Petri Nets.

It Can Describe The Attributes And Behaviors Of AMC.

Furthermore, the Model Based On This Approach Has The High Degree Of Flexibility And Reusability.

Keywords: The definition that preface of Agile Manufacturing Manufacturing Cell Modeling Technique Petri Net creates unit adroitly results from make adroitly, it emphasizes production resource changes according to producing the job and reframing quickly, make production system can answer the change of the product quickly, satisfy changeful market demand. A nimble production unit (Agile Manufacturing Cell) it is the resource configuration that a group of need according to specific production task combine quickly, when producing task happening to change, it can change according to the task characteristic, organize new resource configuration by oneself on original basis. With traditional production system likeness, also need to have the support of the model to producing the analysis of unit, design adroitly, and, because make unit have adroitly flexible and can reframe quality, as the change of production environment its oneself structure also is in produce change, accordingly, be the same as phase of general production system model to compare, the model that depicts nimble production unit must have sex of put sb in a very important position, when making unit structure produce change adroitly its can reflect this one change quickly. The object-oriented technology that build a model [1][2][3] and Petri net [4] builds modular domain to receive wide application in production system, but they are put in the limitation with particular move. Build the model of the dispute formalization that modular technology builds object-orientedly, lack method of effective model analysis, test and verify, abstract sex, accuracy is insufficient. The condition number of the Petri wire mould adds a system condition space that counts as network system node shows exponential relation to increase, this makes with it the system with complex description makes the work with a painstaking take time, and the sex of put sb in a very important position of the systematic model that it builds is very poor. Accordingly, "Compound build a model " the concept appeared, the dominant position that uses all sorts of methods that build a model integratedly namely will build production system model. Compositive object-oriented Petri net (method of Integrated Object-oriented Petri Net) is among them typical delegate, this kind of method is used close (Gate) will join the Petri of different object child net, the put sb in a very important position that realizes systematic model [5] , but close means of this kind of join to handle complex production system effectively to control logic hard. Net of the Petri when the article put forward a kind of object-oriented ode (Object-Oriented Timed Petri-Net, OOTPN) establishs modular method, it can depict the sex of put sb in a very important position that makes unit and complex control have height logically adroitly. The definition of the net of the Petri when defining object-oriented ode of net of the Petri when 1 object-oriented ode is as follows: OOTPN=(P, tg, the Pi in K) type - P of net of the Petri when the ode of physical object - the gather Tgij of Pi - the transition of join Pi, Pj is transitional Tg - the gather K of Tgij - transfer certainly the differentiate regulation part that how changes produces. There are corporeal shedding and iformation flow in production system, and information is having main effect in nimble production unit. Because this is in OOTPN, become a branch of Petri net two kinds big, namely resource (Resource Place) with information (Information Place) . Resource represent resource state, resource the condition of the resource be reachinged by treatment object that medium your card indicates production system is medium, its flow in Petri net states the content in the system sheds the change that reachs resource position, information the news that your card represents to be delivered in the system, its flow uses descriptive iformation flow. Because it introduced time idea,net of the Petri when adopting an ode is, can describe the time that transitional place needs, more the analysis that is helpful for production system. In the meantime, input, output introduced in Pi concept, alleged input, output it is net of the Petri when the ode that points to this physics object and other physics object model happening concerns interactively, input the result of a wire mould of the Petri when the ode that is other physics object changes, output the condition that a wire mould of the Petri when the ode that is other physics object changes occurs, they are the interface that model of network of the Petri when this physics object is endowed with and model of other physics object produce to concern interactively. Input, output of the concept introduce drew lessons from object-oriented technology to enclose character mediumly, those who enhanced model of network of the Petri when the ode is modular characteristic. Such Pi can define as follows: Pi=(SP, ST, f, w) the SP={SPr in type, SPm} is the SPr={spr1 in rally pattern, spr2, ... , sprn, spinr1, ... Spinrj, spoutr1, ... Spoutrk} is resource gather, spinr is an input, spoutr is output a SPm={spm1, spm2, ... , spmx, spinm1, ... Spinmy, spoutm1, ... Spoutmz} is information gather, spinm is an input, spoutm is output a ST={st1, st2, ... the ST1 of gather SP è that Sts} is move? , SP? ST= ? , ? For ì of empty collect F (è of SP × ST) (the gather W that ST × SP) is concern of going from place to place to have Xiang Hu - the authority of arc. Transfer the input that transitional Tg is the OOTPN model in different physics object, output between the changes that happen, it decides the correlation between physical object. When the transition between physical object changes is occurring when conflict, the transition that differentiate regulation K uses affirmatory conflict to center is transitional how to happen. The process building a model of 2 nimble production unit uses OOTPN method to build the process that makes unit model adroitly to be as follows: (1) makes unit equipment resource undertake aggregate classification adroitly to forming according to object-oriented technology; (2) builds OOTPN current model for resource of every kinds of equipment, each specific facility in using successive mechanism to be able to be nimble production unit accordingly build OOTPN model; (3) definition transfers the join of the OOTPN model of each device that changes uses in unit; (4) is tectonic on the foundation of afore-mentioned measure the OOTPN model of whole unit. Below the method building a model model of bat around OOTPN. Nextpage2.

The resource of 1 nimble production unit classifies the equipment resource that forms nimble production unit is the foundation of task of the treatment that finish, the behavior of these equipment resource also is the foundation of whole and unit behavior. It is OK to use object-oriented method polymerization resembles a structure in production unit and the equipment resource with functional similar character in couples kind, establish a target further kind hierarchy concerns and make clear its successive relation. The main treatment facilities in creating unit generally speaking depends on its structure and functional character to be able to differentiate for the following 3 kinds big: (1) machines kind of equipment. Machining kind of equipment is to point to can finish a kind or a few kinds of equipment that machine craft, like common treatment machine tool (lathe, milling machine, grinder... ) , NC, machining center, solder the robot. Status of precision of the treatment method that the attribute of this kind of equipment basically includes facility, size range of pipe bent, treatment, facility (treatment, disengaged) wait, behavior has workpiece of outfit, discharge, treatment workpiece to wait. (2) carries kind of equipment. Carry kind of equipment between responsible equipment of workpiece deferent, resemble guiding bringing car, conveyer belt to wait is to carry kind of equipment a variety of robots, automatically, even, the workpiece that finish carries the worker of the task to also can be a kind to carry equipment by abstraction, its main attribute includes to carry state of limits, seat, equipment (carry, disengaged) etc, carrying limits among them is to show it is accessible other equipment. (3) storage kind equipment. Storage kind equipment is used at memory workpiece, resemble the stereo storehouse of automation, i/O buffer, even of workpiece also can be regarded pile upingly to be a kind of storage temporarily kind equipment. Its most significant action stores namely workpiece and extraction workpiece, the main attribute of this kind of equipment is to store among them the amount of workpiece and sort and its memory capacity. 2.

2OOTPN equipment natural resources is current of the model build it is on the base that the equipment resource with pair of nimble production medium unit has classified, build OOTPN model for resource of every kinds of equipment. Above all, according to the analysis of the character to all sorts of equipment resource and behavior, wire mould of the Petri when building an ode for resource of every kinds of equipment, built model wants to be able to reflect the character of resource and action. Next, the input of affirmatory model, output. Input, output it is this equipment and model of network of the Petri when other equipment is endowed with produce mutual concern, they are the interface that model of network of the Petri when this equipment is endowed with and other equipment model produce to concern interactively. Graph 1 it is the OOTPN model that machines kind of equipment, notable is to need to carry kind of equipment to lade the equipment of workpiece and do not need to carry kind of equipment to lade the model of the equipment of workpiece is different, it does not need a figure 1 medium M2, M3, M4, M5, be located in brim of line draw a frame round for input, output. 2.

3 transfer transitional definition transfers the input that changes is the OOTPN model in different equipment resource, output between the changes that happen, the OOTPN model that the OOTPN model that it will make each equipment resource in unit adroitly presses certain control logic join to become complete unit, that is to say, transfer changes decided to the synergic relationship between resource and interactive mode are made in unit. In making unit model specificly adroitly, transfer to spark transitionally means and spark the control that order decided unit is logistic. A few transfer to spark transitionally the concerned character that depends on Petri net can decide, if pursue,2(a) place is shown. However, transfer a few more additionally transitional sparking needs to introduce corresponding differentiate regulation in the model, the situation that the character of net of Petri of this kind of Chan Ping cannot decide and needs to introduce differentiate regulation says for conflict, corresponding differentiate regulation calls conflict differentiate regulation. Particular case can divide the conflict according to in the model it is 3 kinds: (1) transfers conflict exists between changes, already two or many transfer changes has identical input, must input certainly spark which transfer transitional, the conflict in this kind of circumstance and general Petri net is consistent. When unit medium workpiece chooses to machine equipment or be a choice this kind of conflict can produce normally when facility for transporting is carried, applicable is the shortest handling time is the preferential, shortest carriage method is preferential wait for differentiate regulation to resolve conflict, if pursue,2(b) place is shown. (2) sparks transfer a transitional conflict between medium your card, below this kind of circumstance, transfer to input a medium your card transitionally to count over spark the your card number that transitional place wants, need decides your card is sparked by what corresponding changes. Produce this kind of conflict normally when the workpiece in buffer enters a system to machine, applicable is the earliest date of delivery is preferential wait for differentiate regulation to resolve this kinds of conflict, if pursue,2(c) place is shown. (3) sparks transfer a transitional conflict between, corresponding changes can be inputted by what differ will spark. Below this kind of circumstance, the input that can differ correspondence of transitional translate into many changes will handle, if pursue,2(d) place is shown. When many workpiece competitive facility for transporting or treatment facilities produce this kind of conflict constantly, applicable is the shortest handling time is the preferential, earliest date of delivery is preferential wait for regulation to resolve conflict. 2.

The OOTPN model with 4 whole and unit construction. In above on the foundation of 3 paces, with transfer the OOTPN model join of each equipment in transitional will nimble production unit rises, made the OOTPN model of whole unit. When nimble production unit produces change, fine with predefine installation kind OOTPN model can construct for the foundation the OOTPN model of new facility, repass transfers changes has new link, in transfer the circumstance that conflict exists in changes gives a definition differentiate is regular, formed new production unit model so, and while unit model is affirmatory, control also decided logically come down. A case that uses OOTPN method to build nimble production unit is below Nextpage3 example research. This unit uses treatment casing kind spare parts, it is guided automatically with by a two Mandelli-7u machining center, communal buffer bring a car to form, its plane position is shown 3 times like the graph. The machines kind of equipment model that the model of Mandelli-7u machining center and graph show 1 times is similar, it is its workpiece assembles and unassemble only do not need a robot or emphasize assembling and unassemble equipment, the model of buffer is shown 4 times like the graph, the model of the car is shown 5 times like the graph, the model of whole unit is shown 6 times like the graph. By the graph 6 knowable in this model existence transfers 7 times transitional, tg1 expresses buffer of carry back of car general workpiece, tg2, Tg3 states the workpiece of buffer is machined by two machining center, tg4, Tg5 states the car carries workpiece respectively to machining center 1 or 2, tg6, Tg7 states the work that machining center processes is carried by the car. Among them, once Tg2 happens, mean work by machining center 1 treatment, criterion Tg4 happens certainly, namely the car carries work to machining center 1, tg3, Tg5 also is such, have logic of the following control so: IFTg2ThenTg4, IFTg3ThenTg5. Because make model of unit two machining center identical, the work that enters unit treatment is achievable on a machining center full treatment working procedure, accordingly, once Tg6, Tg7 happens, the car must remand workpiece buffer, criterion Tg1 happens certainly, controlling logic is: IFTg6ORTg7ThenTg1. In the meantime, existence conflicts between Tg2, Tg4, decide workpiece is machined by which machining center namely, belong to in front the conflict of the first kind of discussion kind, the regulation with the shortest first handling time comes to applicable affirmatory, the changes that needs time weak point already is first spark. Spark a conflict of the existence between medium 0 cards of Tg2, Tg4, decide which workpiece enters unit treatment first already, belong to in front the conflict of the 2nd kind of discussion kind, the regulation with first time of the earliest delivery comes to applicable affirmatory, make a shop sign early first on behalf of delivery time already spark transitional. Tg6, Tg7 also makes conflict part, namely the service that which machining center gets a car first, belong to the conflict of the 3rd kind of type, the regulation that applicable serves first first undertakes deciding, namely changes has similar first step, spark with same probability. The place on 4 conclusion put together is narrated, the article is aimed at the characteristic of nimble production unit, offerred the means building a model of net of the Petri when a kind of object-oriented ode, can describe the control logic with nimble production complex unit, and the sex of put sb in a very important position that built model has height. This kind of method builds OOTPN model for resource of of all kinds equipment above all, these equipment resource models make the fundamental component part of tectonic and whole unit model, assure the sex of put sb in a very important position of the model thereby, next through transferring changes and differentiate introduce the production environment with particular basis regularly to define the correlation between these component, describe the action of whole unit. Should form unitly when producing change, simply is revised on the foundation of component of equipment resource model or redefine transfers regulation of transitional, differentiate can form new unit model. Accordingly, this kind of method that build a model has the following advantage: (1) this kind of method is component part with equipment resource model, with transfer changes and differentiate regulation decide the connection between component part, construct then the model of whole unit, those who have height is modular characteristic; (Of model of 2) equipment resource build derive object-oriented thought, once the model of some kind of equipment is built, in can be being used at differring to build a model unitly, have sex of put sb in a very important position; (When 3) should make environmental happening change, through revise or redefine transfers regulation of transitional, differentiate can describe new unit structure, the model that this kind of method builds is had flexible; (Once 4) decided transfer changes and corresponding differentiate regulation, also decided unit control is logistic, the design that controls a system for unit and development provided a basis. 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