人员疏散软件Pathfinder介绍及应用 The background of Pathfinder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Thunderhead Engineering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 Thunderhead Engineering公司同时开发了现今广泛使用的基于FDS的烟气模拟软件Pyrosim The Basic Graphical User Interface of Pathfinder： 快捷工具栏菜单栏工具属性定义区导航菜单栏模型区 A unique feature of pathfinder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 Pathfinder provides three main views for working on evacuation models: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 3D View: This view shows a 3D representation of the current model. The model can be explored and modified using various tools(The 3D are the main views in which drawing is performed in Pathfinder) 2D View: This view is very similar to the 3D View, but it provides an additional snapping grid and an top view of the model. You can draw some stand room geometry easily in this view with the help of those grids.You can define Room properties in this panel Pathfinder is built on the idea of creating floor space on which occupants can walk. Floors are the primary method of organization in Pathfinder. At their most basic level, they are simply groups in which rooms, doors, stairs, ramps, and exits .You can define it’s property after choosing a floor Importing Filesimage (GIF JPG PNG)CAD(DXF、DWG)PyroSim and FDS filesThe imported image is added to the Imported Geometry →Background Images group in the 3D View. Work with Importing FilesImagesAfter a file is selected, a new dialog will appear allows properties of the image to be specified so that the proper scaling, rotation, and offset can be applied. Drawing rooms over a background image CADThe first prompt asks the user to select the base unit in which the CAD file was created.Options: The options prompt allows the user to specify more options for import. extract room from CAD fileswith this button PyroSim and FDS files :room extracted from a PyroSim file with this button too The component of a floorOnce rooms have been extracted using the 3D or 2D room extraction tools, the model will still be missing doors and stairs.Door between two roomsStair between two floorsRoom Walls and other impassable areas are represented as gaps in the navigation meshYou can only sepruate two rooms by gap and here is a gap without any thickness OccupantsIn Pathfinder, occupants are defined in two parts: profiles and behaviors. You can define the occupant’s profile and behavior here The profile defines fixed characteristics of the occupants, such as maximum speed, radius, avatar, and color. The behavior defines a sequence of actions the occupant will take throughout the simulation, such as moving to a refuge area, waiting, and then exiting.You can either use default profile and behaviors or define new one The Behavior tab allows you to set options for Pathfinder's two primary simulation modesSFPE： 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Simulation modes Additional actions can be added to any behavior. To add an action, select a behavior or existing behavior action. The property panel will show a drop-down button with the description of an action that can be added.With the new behavior selected, the behavior property panel will appear Choose one action and click-drag on the model Those on the red area will be influence by the actionAttention : one occupant follow behavior firstly and action sceondly These specific values will never change unless the distribution is changed in the profile. This ensures that two simulation runs with the same input model will give the same answer. New distribution of profiles can be generated for occupants by right-clicking the occupants and selecting Randomize. 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 Cad information in this exampleStair 3.2mDoor 1.425mRoom 30m*20mFloor 0.0mFloor 0mFloor 2.5m Creating Movement SpaceAdd new floorHere is the new floor Import CAD files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Button for creating stairButton for creating doorDefine stair propetyDefine door propety 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Floor 0.0，右键，选择Add occupants键入Floor 0.0 中疏散人数Floor 2.5 m 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→run simulation Summary ReportThe summary report file contains information about the simulation geometry, simulation performance,and usage information for each room, stairway, and door. Pathfinder also provide output in the form of 2D time history plots of CSV (comma separated values) out files and a text summary of room clearing times and doorway flow rates. 。