室内低位火焰位置与门缝光影特征关联性研究

Study on the correlation between position of indoor low-level flame and the light characteristics through the door slits

为研究全遮挡环境下,如何通过门缝光影来定位室内低位火焰,搭建了一个ISO 9705标准房间,门与地面处设90 cm×2 cm的缝,使用0.5A标准木垛火模拟室内低位起火燃烧,通过室外摄像头记录门缝光影变化,耦合MATLAB亮度识别和图像处理技术,分析门缝光影变化规律,探究室内低位火焰位置与门缝光影特征的关联性。结果表明:某一亮度阈值下,门缝光影轮廓大致呈四边形,当火焰位于门面中轴线上时,门缝光影轮廓呈等腰梯形,而当火焰偏向一侧时,光影向其对侧偏转。随火焰距门面中点距离的增加,门缝光影四边形的腰线夹角减小,而它的高(称作门缝光影延伸距离)先增加后减小。室内低位火焰位置可与门缝光影四边形的几何参数建立关联;火焰距门面中点距离与门缝光影延伸距离的关系可用分段函数进行表征。研究可为火灾事故后通过视频定位室内低位火焰位置提供参考。

In order to study how to locate the indoor low-level flame through the door slit light characteristics under the full oc⁃clusion environment,a ISO 9705 standard room was con⁃structed,with a 90 cm×2 cm slit between the door and the floor,and a 0.5A standard wood stack fire was used to simulate the in⁃door low-level fire.The change of the door slit light characteris⁃tics was recorded by the outdoor video,and the change rule of door slit light characteristics and the correlation between the in⁃door low-level flame position and the door slit light characteristics was analyzed,coupled with the MATLAB luminance recognition and image processing technology.The results show that the geom⁃etry of the door slit light was roughly quadrilateral under a certain luminance threshold,when the flame is located in the center axis of the door,the geometry is isosceles trapezoidal,and when the flame is biased to the side,the door slit light is deflected to its op⁃posite side.As the distance of the flame from the door increased,the angle of the quadrilateral girdle decreased,while the exten⁃sion distance of the door slit light first increased and then de⁃creased.The correlation was obtained between the indoor lowlevel flame position and the geometric parameters of the door slit light.The distance of the flame from the door and the extension distance of the door slit light can be characterized by the segmenta⁃tion function.The study can provide a technical reference for lo⁃cating the position of indoor fire after a fire accident by video.