pathfinder软件的使用

人员疏散软件Pathfinder介绍及应用ThebackgroundofPathfinder性能化主要由两部分组成，烟气和人员疏散目前国际上常用疏散软件有：STEPS、SIMULEX、SGEM、buildingEXODUS、Pathfinder等Pathfinder是由美国ThunderheadEngineering公司开发的一个基于进出和人员运动的模拟器。它提供了图形用户界面的模拟设计和执行，以及三维可视化工具的分析结果。ThunderheadEngineering公司同时开发了现今广泛使用的基于FDS的烟气模拟软件PyrosimTheBasicGraphicalUserInterfaceofPathfinder：快捷工具栏菜单栏工具属性定义区导航菜单栏模型区Auniquefeatureofpathfinder目前广泛使用的几款疏散软件生成的人员疏散模型往往是由一定体积的网格组成，例如buildExodus,其模型就是由0.5*0.5的网格组成，且模型为二维，比较不直观Pathfinder运动的环境是一个完整的三维三角网格设计，以配合实际层面的建设模式，生成的人员疏散模型为一个整体，且模型为三维结构，与实际建筑契合Pathfinderprovidesthreemainviewsforworkingonevacuationmodels:导航视图：该视图列出了在分层格式模型中的所有对象。它可以用来快速定位并通过名称修改对象。3DView:Thisviewshowsa3Drepresentationofthecurrentmodel.Themodelcanbeexploredandmodifiedusingvarioustools(The3DarethemainviewsinwhichdrawingisperformedinPathfinder)2DView:Thisviewisverysimilartothe3DView,butitprovidesanadditionalsnappinggridandantopviewofthemodel.Youcandrawsomestandroomgeometryeasilyinthisviewwiththehelpofthosegrids.YoucandefineRoompropertiesinthispanelPathfinderisbuiltontheideaofcreatingfloorspaceonwhichoccupantscanwalk.FloorsaretheprimarymethodoforganizationinPathfinder.Attheirmostbasiclevel,theyaresimplygroupsinwhichrooms,doors,stairs,ramps,andexits.Youcandefineit’spropertyafterchoosingafloorImportingFilesimage(GIFJPGPNG)CAD(DXF、DWG)PyroSimandFDSfilesTheimportedimageisaddedtotheImportedGeometry→BackgroundImagesgroupinthe3DView.WorkwithImportingFilesImagesAfterafileisselected,anewdialogwillappearallowspropertiesoftheimagetobespecifiedsothattheproperscaling,rotation,andoffsetcanbeapplied.DrawingroomsoverabackgroundimageCADThefirstpromptaskstheusertoselectthebaseunitinwhichtheCADfilewascreated.Options:Theoptionspromptallowstheusertospecifymoreoptionsforimport.extractroomfromCADfileswiththisbuttonPyroSimandFDSfiles:roomextractedfromaPyroSimfilewiththisbuttontooThecomponentofafloorOnceroomshavebeenextractedusingthe3Dor2Droomextractiontools,themodelwillstillbemissingdoorsandstairs.DoorbetweentworoomsStairbetweentwofloorsRoomWallsandotherimpassableareasarerepresentedasgapsinthenavigationmeshYoucanonlysepruatetworoomsbygapandhereisagapwithoutanythicknessOccupantsInPathfinder,occupantsaredefinedintwoparts:profilesandbehaviors.Youcandefinetheoccupant’sprofileandbehaviorhereTheprofiledefinesfixedcharacteristicsoftheoccupants,suchasmaximumspeed,radius,avatar,andcolor.Thebehaviordefinesasequenceofactionstheoccupantwilltakethroughoutthesimulation,suchasmovingtoarefugearea,waiting,andthenexiting.YoucaneitherusedefaultprofileandbehaviorsordefinenewoneTheBehaviortaballowsyoutosetoptionsforPathfinder'stwoprimarysimulationmodesSFPE：SFPF模式使用了火灾防护设计手册中的SFPE概念，模式中行人不会相互影响，即互不避让并可互相穿透。人员的行走速率由每个房间的人群密度决定，通过出口的人流量则由出口宽度决定，以流量为基础的选择意味着人员会自动转移到最近的出口。STEERING：Steering模式使用路径规划、指导机制和碰撞处理相结合的手段来控制行人运动，人员之间的距离和最近点的路径超过某一阈值的时候，算法就会产生新的路径，从而改变了行人的行走轨迹。疏散人流量不受门限制，疏散人员之间保持一定间距注：由于steering模式更接近现实，仿真中我们均使用steering模式。SimulationmodesAdditionalactionscanbeaddedtoanybehavior.Toaddanaction,selectabehaviororexistingbehavioraction.Thepropertypanelwillshowadrop-downbuttonwiththedescriptionofanactionthatcanbeadded.Withthenewbehaviorselected,thebehaviorpropertypanelwillappearChooseoneactionandclick-dragonthemodelThoseontheredareawillbeinfluencebytheactionAttention:oneoccupantfollowbehaviorfirstlyandactionsceondlyThesespecificvalueswillneverchangeunlessthedistributionischangedintheprofile.Thisensuresthattwosimulationrunswiththesameinputmodelwillgivethesameanswer.Newdistributionofprofilescanbegeneratedforoccupantsbyright-clickingtheoccupantsandselectingRandomize.Pathfinder使用实例Pathfinder使用实例一新建楼层以一个简单的实例介绍Pathfinder的基本使用，模拟一个两层（一层层高2.5m)建筑的人员疏散CadinformationinthisexampleStair3.2mDoor1.425mRoom30m*20mFloor0.0mFloor0mFloor2.5mCreatingMovementSpaceAddnewfloorHereisthenewfloorImportCADfiles用该按钮导入CAD图纸，分别定义单位、高度导入的图纸显示如下选中该工具生成网格生成的网格：原CAD图纸添加楼梯、疏散门ButtonforcreatingstairButtonforcreatingdoorDefinestairpropetyDefinedoorpropety添加楼梯和疏散门之后的结构如下：楼梯疏散门添加疏散人员：选中Floor0.0，右键，选择Addoccupants键入Floor0.0中疏散人数Floor2.5m同样设置至此，疏散模型建立Pathfinder具有友好的人机界面，也可经过简单调整，模型变成如下界面：菜单栏simulation→runsimulationSummaryReportThesummaryreportfilecontainsinformationaboutthesimulationgeometry,simulationperformance,andusageinformationforeachroom,stairway,anddoor.Pathfinderalsoprovideoutputintheformof2DtimehistoryplotsofCSV(commaseparatedvalues)outfilesandatextsummaryofroomclearingtimesanddoorwayflowrates.