acooperativeagentmodellingapproachforprocessplanning-外文文献(编辑修改稿)

acooperativeagentmodellingapproachforprocessplanning-外文文献(编辑修改稿)内容摘要：

information on the monitor.The time adapter is used to count time in thecourse of process planning.The schedule adapter is responsible for schedulingevents such as proposal generation, proposal evaluation, and conflict resolution. When an iningproposal from another agent is detected, the adapterschedules an evaluation event. When a process planning problem is detected, it then schedules a proposal generation event. Both kinds of events will beassigned a priority at the same time of event generation. If a conflict resolution is required, then theadapter schedules a conflict resolution event andassigns it the highest priority. Whenever a negotiation is required, the adapter immediately suspendsother events and fires a negotiation effector.When a problem arrives, the Pagent first invokesthe effector ‘WatchProblem’ to examine the problem. Afterwards, it creates a ‘problem examined’event. At the same time, it generates the facts of theproblem. Responding to the ‘proposal generationtask’ event, the effector ‘GenerateProposal’ generates a proposal and creates a proposal ‘GeneratedEvent’. This event results in the facts of the proposal.Responding to the task event created by theschedule adapter, when the task name is ‘proposalgeneration’, the ining proposal is evaluated. Theadapter checks if the adapter has already generatedan interacting proposal. If yes, it links the twoproposals and notifies the proposal originators of itsintent to evaluate the new proposal. In this case, itevaluates the already generated proposal. If the proposal adapter has not yet generated an interactingproposal, the adapter searches the scheduled pendingtasks for related generation tasks. It checks to see ifit has already started working on a proposal or isplanning to start. If yes, it links the evaluation andgeneration tasks. In this case, it evaluates the proposal with the triggering proposal generation. If thetriggering proposal is acceptable, it may not benecessary to generate a separate proposal or a proposal can be generated which is tailored to integratesmoothly with the triggering proposal. If there are nocurrent plans to work on a related proposal, theevaluation task only evaluates the ining proposalaccording to agent knowledge. The Pagent whichoriginated the triggering proposal is then notified.If a conflict is notified from another agent, theconflict resolution responds to this event to resolvethe conflict. After the adapter responds to the conflict event, it first judges the conflict situation. Thenit invokes the relevant strategy to resolve the conflict.. Knowledge representationThe CoCAPP system’s knowledge is about product representation and agent knowledge. Each Pagentin the CoCAPP system has three types of knowledge: domain knowledge, control knowledge, andconflict resolution knowledge. The Bagent has onlycontrol knowledge. The part representation is aboutthe problem description. It is monly shared byall agents within the CoCAPP system.. Part representationA part in the Machining CoCAPP system consistsof two kinds of data. One kind is about the constraints to the generating plan. Another kind is aboutits geometric information. They are described asfollows: fl CONSTRAINT production time, cutting force,.machining power。 fl PART Name。 Type。 MaxSize。 Material。 InitSta.tus。 HeatTreat。 Features .The Name is the identifier of a part. It must beunique. The Type is the keyword of the part to showits outlook shape. The MaxSize gives the maximumenvelope size of the part. The Material is the material kind of the part. The InitStatus is the raw status(). Zhao et in Industry 41 2020 83–9788of workpiece with which the part can be fabricated.The HeatTreat is about the part heattreatment condition. The Features are a collection of all features. Afeature is represented as follows: fl FEATURE Name。 Type。 Location。 FinalSize。 .InitSize。 Hardness。 TolerancesThe Name is the identifier of a feature. It must beunique. The Type is the keyword of the feature. Thefeature Location is about the original position anddirectional vector of the feature. The feature size, . including final size FinalSize and initial size Init.Size , is the dimensional value of the feature. TheHardness is about the feature’s hardness. The Tolerances are about dimensional and geometric tolerances. A keyword is assigned to tolerance to distinguish the tolerance content.. Domain knowledgeThe domain knowledge of each Pagent is aboutthe descriptions of its process planning capabilities,and used to generate proposals, evaluate proposals,and resolve conflicts. Different agents may havedifferent formats for domain knowledge representations such as databases, analytical algorithms, etc.The domain knowledge can be extracted from manuwxfacturing handbooks such as 19–21 . Each Pagenthas a different domain knowledge content.For example, the operation selection agent is usedto generate machining operation alternatives for defined features of parts. For each given feature, theremay exist more than one possible operation. Sometraditional machining methods such as forging, diecasting, drilling, turning, milling, boring, shaping,grinding, lapping, honing, and diamond boring, etc.,have been built into the domain knowledge base. Itscontent includes the relationship between operationswith parameters such as machinable feature, workpiece material, tolerances, preparatory operation, timecalculation equation. The knowledge is representedas facts in a semantic as shown in Fig. 3. In theknowledge base, an operation fact is stored in onenode. All facts are stored in a list.The proposal generation, proposal evaluation, andconflict resolution strategies are embedded in thesolver adapter。