Those who make unit control system build a model
- source:TAMIKO CNC Machining
At Design Stage, the Model Of Cell Control System Is Critical, which Is Utilized To Develop Reusable And Expandable Software Of Cell Control System Easily.
In This Paper, the Generic Architecture Is Defined That Supports Design And Implementation Of Highly Flexible Control Systems For Agile Manufacturing Cells, which Is Based On Generic Resource Models.
The Resource Model Is Established By Integrating Object-oriented Method And Petri Net.
Key Words:cForeword of Ell-control;modeling;agile Manufacturing;Petri Net1 is made adroitly is to make create a when the enterprise answers the change of the market quickly and put forward new production pattern, it asks production system has nimble sex, can trends reframes, in order to get used to the need that different product produces. It is primary production unit of the foundation with unit, can recombine a new production quickly to make a system according to market demand. Consequently, of production unit can reframe the gender is crucial. Production unit by treatment equipment, carry the physical equipment composition such as hardware of equipment, computer, make the reset that reframing unitly is physical equipment. Although can mix machine tool, robot,the physical equipment such as the computer serves as building blocks piece, build a production system, but the software that controls these device must be developed technically. Carry out make adroitly, the notional influence of nimble sex controls a system to unit, when production unit reframes, ask nimble production unit controls a system to be able to be produced by fast and effective ground or must be revised. To satisfy this kind of requirement, unit control software should be had modularity and but sex of put sb in a very important position, the unit control model that builds in design phase is crucial. Article discussion makes unit accuse those who make a model to build adroitly, the system that put forward to be based on production resource model controls a model. Petri net has a graph to express to analyse the character that controls logic with maths, apply extensively at making automation system build a model. Object-oriented technology provided the connection with man-to-man nature between the object in the physical object to make a system and software. The control model that the method that is united in wedlock with object-oriented method and Petri net photograph will come to indicate resource, build OPN model, easy implementation model arrives between control software change. 2 unit control a model to press object-oriented analytic method, production system is by production substance 3 kinds of objects such as object, information object and control object comprise  . Make hypostatic object in order to describe of all kinds equipment; Description of information object in order to dominates the of all kinds static state that the system uses and dynamic news, these information often are put in the database; If the job of of all kinds control that controls an object to implement a system attempers, diagnose and control. Object-oriented technology provided the connection with man-to-man nature between the object in the physical object to make a system and software. Design controller with object-oriented method, we call the boy or girl friend that answers relatively with physical resource in controller fictitious resource (VE) object, if the graph is shown 1 times,control a model for unit. In controller there is a client between each object / the service concerns, transfer activity of the mutual control that finish through the message. Superstratum is controlled (the order that SC) object decides what to do and executes the mission to rock-bottom VE object, the plan that SC wants to carry out controller, attemper and control a function, still include to optimize and lock up processing to death. The characteristic of this unit control model is: (1) intelligible sex. Because control systematic structure to be similar to physical structure of the system, the physical object of production system and software formed the connection with man-to-man nature between medium object; (2) is flexible. Because the object can be replaced, new process designing and in adding a system respectively, won't make control the change with systematic big happening, those who control a system is flexible will increase; (3) simple sex. In give rank below control mode, the design of ranking control object will be simplified by apparent ground, because be to consider a complex task merely (carry and install) of a spare parts, is not a consideration all child the task (device of moving robot program, clamp waits) a moment; (Sex of 4) put sb in a very important position. Controller will have the package that fits put sb in a very important position and the design of package is simple also. Graph 1 unit accuses patternmaking 3 fictitious resource the special mission that fictitious resource object executes production resource and the current condition that record production resource. According to the type of resource of physics of fictitious resource pilot, fictitious resource divides 3 kinds: Machine equipment: They can make product function happens to physics changes and change logically, exemple: CNC machine tool (physics changes) and measure workstation (logistic change) . Store equipment: They can store only product, the character of unalterable product, exemple: Local bumper and store system. Facility for transporting: In treatment equipment is mixed store the product is carried between equipment, exemple: AGV, machine support of the people carries plant. In controller between each object, deferent is high-level message, but between the physical equipment that represents in every fictitious resource and it, agreement of use appropriative word. To simplify the implementation of fictitious resource, fictitious resource cent becomes two parts, namely current share and special share, see graph 1b, current ministry deal out gave the abstract description of resource, build a model according to resource condition builds a model or using Petri network; Special share realizes the high-level function that current share assumes, consequently, superstratum controlled an object to offer same message interface for all fictitious resource. The main function of the current share of fictitious resource is the current condition that records exterior resource, and to the middle of controller other object sends message and the message that accept other target. Because current share can handle high-level message and exterior resource to be able to handle physical installation only only,have some agreements, consequently, the message must be changed, the main function of the special share of fictitious resource is to change send the message to physical equipment and the message that come from physical equipment. In addition, when the function that lacks current share agreement when physical device is characteristic, this function character comes true by the special share of fictitious resource. The concept of the high-level word agreement that we offer special be similar to production message standard (the international standard of MMS)  , but some are different. The first, MMS simplified the communication between controller and equipment, but it does not support the message is based on between each object communication in controller, consequently MMS lack is used at cooperative control implement the active service between each object. The cooperative control that included place to need in high-level word agreement implement the service between each object, but, can use MMS to achieve high-level word agreement, for example: Of use MMS keep variable service. The 2nd, fictitious production unit was included in MMS standard (the concept of VMD) , its action is similar to the action of the current share of fictitious resource, it provided a current function model with abstraction already, also offerred unified port to all physics equipment, it and special function and communication ability have nothing to do. But VMD gives out only an interface, the high level that requires without us serves, the equipment position of the facility status in VMD and fictitious resource is different, the state information of VMD gives out to correspond with other equipment only whether possible information, and should give out in fictitious resource the state information with concerned more detailed equipment, for example: Clamp device is to be in clamp or loose condition, whether is equipment processing the state information such as the spare parts. 4 resource model is mixed for the design the current share that achieves fictitious resource, build model of current natural resources, this model describes some kind of resource (the common property that 1b) seeing a picture has. To increase flexible with standardization, rapid development unit controls a system, will establish warehouse of model of current natural resources (1c) seeing a picture. Model of current natural resources includes information model and control model, among them information model includes resource to describe information, resource state information, mistake to handle information, tie information and process capability information to wait. Control model states the dynamic character of resource and control are logistic, will express with object-oriented Petri net, namely OPN model, model of so easy implementation arrives between control software change. As a result of same kind resource has identical character and identical control interface, because this is OK,build a model with same method. The common resource that the first condition that establishs warehouse of model of current natural resources is pair of production unit that have domestic and internationally undertakes an analysis, sum up their function, form a relatively current resource model. 4.
1 information model makes resource to every, control system needs to express with information model, basically have following news: Descriptive resource information defines the character of every resource. This information is a static state. Natural resources of description of resource state information is current condition (the current clamping apparatus, current likely cutting tool, current product or spare parts, order that already held currently, wrong code and command code) dynamic information. This information is retrieved by control system and update. The wrong condition that resource treats wrong message description to give in place leaves the message of finished action. Resources capacity information describes resource to be able to finish the information of what operation. This information is divided into static part and dynamic part, static part depicts the faculty with inherent resource, dynamic part describes current capacity. Resource restrains the tie that information natural resources carries out, be like: Hypothesis product can flow to a direction only between two machine tools. 4.
The different position that 2 control model controls a model to indicate fictitious resource (movement) with migratory incident (message) , will express with object-oriented Petri net, namely OPN model. Petri net is the powerful tool that studies system of disperse incident trends, it is by and migratory the digraph that these two kinds of node form, can describe resource clearly to reach the condition of changeover happening in the mutual changeover among production system. Of production system build a model, emulate, attemper reach control to often use Petri network, but all right now Petri wire mould equipment in involving a system, to build the control model of fictitious resource, need undertakes decomposing to model of systematic Petri network. Above all, some is involved to plant only in Petri net an is marked to be this resource with migratory part Petri net of resource piece; Next, find out be located in this kind of Petri net piece brim involves correspondence of place of other natural resources migratory, with information a will state this plants migratory happening condition that replaces correspondence of place of other natural resources or it is the result that it causes. We can build the Petri network model of fictitious resource respectively, the current model of fictitious resource uses treatment machine tool Petri net description, if pursue,2 are shown. This kind of model is as follows to the changeover regulation of software of fictitious resource object: T11: ? 12: of of thistle of Jia of draw water of ministry ? Does eat vase 13: of of sanded Jia thistle? 14: of of languid of ち of commonplace of ability of ministry ? Does ministry place 15: of the that read languid? Does eat vase still right Zuo 16: ? Is badger of cloth Hu anxious 17: receiving Xi ? 11: of Xi of Ou of Qiao of incomplete Fan? 12: of Man of take along sth to sb of ⒖ of ministry Zhan? 13: of of thistle of Jia of Lei of cabin ? Does cabin closely question however 14: of Ao Zuo ? Does cabin brag commonplace 15: ? Does cabin censure is opposite all right Zuo 16: ? Receive P11: of Zuo of Fan of attentively happy ⒃ ? P14: of of of of thistle of Na Hui Jia? Does of languid leap up collect idle to break Long P13: ? The condition in the net of Petri of current model of natural resources of treatment of? of Wang of Huo of ∥ of a huge legendary turtle of ⒘ of bank of ⌒ of arc of of thorn of Hu of arc of ⑽ of bank of ⌒ of Pi of ㄒ of ill Shan of of of languid Ao the state that represents some kind of resource, express the attribute of fictitious resource. A the Petri wire mould that the graph shows 2 times medium P11, P12, P13, P14, P15, P16 can change the leisure that has for fictitious resource place, initialization respectively, wait to lade, machining, be being uninstalled and; The migratory changeover in Petri net has some operations for fictitious resource place. The Petri wire mould that the graph shows 2 times medium migratory T11, T13, T14 can be changed for initialization (Setup()) , treatment (part of Process()) , strip (the treatment facilities such as Unload()) is fictitious the operation of resource; The information in Petri net the information that changeover is given out for fictitious resource or can receive, the information in the Petri network that the graph shows 2 times foreign control object sends MP11 translate into this treatment facilities is fictitious a kind of message of resource, this message sparks when facility status is leisure the execution that Setup operates, MP12, MP14 is the hair when be being carried out by Load and Unload operation give facility for transporting fictitious resource the requirement assembles and unassemble the message of workpiece, MP13 is facility for transporting fictitious resource sends treatment facilities fictitious resource expresses to assemble and unassemble ending message. 5 last words are based on object-oriented analytic method, the article put forward to make unit control a model, control object and the composition of fictitious resource object that indicate physical resource by superstratum, in controller the communication that is based on a message is used between each object. This control structure can regard unit pilot as referenced model, consult according to this kind model and the physical resource type that form unit system, the special control structure that can design a requirement quickly. To achieve the current share of fictitious resource, built resource Petri network, decided changeover is regular. The work that should do further is the current model warehouse that builds fictitious resource, to realize Gao Rou the gender is mixed but the control software of sex of put sb in a very important position is offerred strong prop up. CNC Milling CNC Machining