Acquiring 3D Data in Sewers

Posted by Olivia Singeron Feb 5, 2021

The wastewater industry is constantly evolving. New developments in technology show us faster and more accurate ways to complete maintenance work—and often with fewer resources. Through these advancements, we get a glimpse into what’s possible in the industry and what more can be learned from our systems underground.3D Sewer Data

Today, we see this in the buzz surrounding artificial intelligence and its potential role in sewer inspections: automatically identifying defects and coding accordingly before a human operator gets involved. And we see this in a shift toward 3D data as an integral part of inspection workflows. When 3D data is acquired, it offers additional insight into sewers.

This data can be used to further characterize defects, and also to build a virtual model of a collection system. A virtual model can benefit engineers in a number of ways, including helping them model flow capacity, better understand operational risks, work more proactively to predict failures, perform what-if analyses, and optimize overall operations. A virtual model can also be used for augmented reality, giving site workers a virtual glimpse at infrastructure underground in order to plan work. There are a variety of methods used for acquiring 3D data in sewers.

Laser Profiling:

激光探頭連接到CCTV履帶並將激光環鑄在管道內壁上。通過下水道進步,軟件從履帶視頻中提取環的形狀。組裝這些連續的橫截麵產生管道內表麵的3D模型。

聲納:

雖然激光分析能夠在水線上方獲得管材幾何形狀,但聲納技術可以在它下麵檢查。使用高頻,短程聲音,聲納探頭掃描牆麵幾何,識別抵消,堵塞,缺陷,淤泥電平,更加附加的管道。為了捕獲流管中的完整幾何輪廓,通常組合激光分析和聲納數據。

Laser Triangulation:

利用激光三角測量,可以捕獲3D測量在表麵上突出激光,然後用相機將其視角。激光器和相機都指向相同的目標區域。了解激光器和相機之間的角度偏移,可以計算深度差異。激光分析是一種激光三角測量的形式,但是該技術也由人孔掃描儀使用以捕獲幾何形狀。

LiDAR:

As with laser triangulation, LiDAR uses laser light to scan 3D space. But instead of relying on geometric calculations, LiDAR uses time-of-flight, wavelength and projection angle to determine the distance and location where a laser point hits an object. Multiply this over millions of points and you end up with a cloud of points that can be stitched together into a geometric mesh. In pipe and manhole inspections, LiDAR can create a continuous 3-D model. The ovality and surface condition of the pipe, joint and positions and offsets, size and location of defects and connections, flow level, and more can be identified from this model. Simple LiDAR rangefinders can also be used for tasks like measuring the depth of a manhole, or the distance to a lateral connection within a mainline.

攝影測量:

With photogrammetry, geometry can be determined by comparing a series of images (usually sequential frames of video) collected during an inspection. Dimensional data is extracted from the footage based on how things change from one video frame to the next. Unlike other methods, this process can be applied to existing inspection video for a retrospective analysis.

地理空間:

地理空間技術將地理信息係統(GIS)和全球定位係統(GPS)結合在世界空間中找到資產。在廢水行業中,GPS設備通常用於建立人孔的位置。在創建汙水係統的全麵GIS映射時,可以使用此信息。鄰接管道的位置和鄰接管的方向用作從資產內收集的位置和定位幾何的參考點,從而幫助將個別資產模型縫合在一起,以單個集合係統的總體模型。

XYZ:

An inertial navigation system (INS), also known as an XYZ sensor, is being added to small-diameter inspection equipment to track the camera’s orientation and position in 3D space. These sensors are beneficial for understanding the location of assets--particularly where lateral and drain lines bend, at what angle, and in what direction.

把它全部拉到一起

Many of these technologies are effective for capturing 3D data from asset interiors, while others are well suited for establishing the position of those assets in world space or the trajectory of a line. When these technologies are combined, it allows for the creation of an all-purpose virtual model. Virtual models can help with flow studies, rehabilitation and maintenance planning, capacity planning, and what-if modeling. Combining traditional inspection data with 3D data can also enable augmented reality (AR), where asset features and parameters are georeferenced—or placed in real-world 3D space--and then overlaid on live video. AR will allow a field technician with a smartphone or inspection camera to see virtual representations of hidden infrastructure and details about an assets’ composition, condition and history.


Did you know the ROVVER X sewer inspection crawler can be equipped to offer laser profiling capabilities in seconds? Learn more about this laser ring accessory:
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Topics:All Topics下水道基礎設施

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