The project was executed by Acropol-Geo with a process inspection and support of 3DLS’s specialists. 3DLS apply advanced geo-technologies in the field of engineering research and GIS, and have spearheaded the development of laser scanning in Russia.
The plant project involved successfully capturing the factory-built documentation, conducting a survey of industrial facilities, performing accurate measurements for the control of construction, creating topographical plans and maps, calculating volumes of mining and storage of bulk products, performing architectural measurements of buildings, scanning and simulating emergency hydraulic power units, capturing the linear objects of pipeline transportation, carrying out a three-dimensional modeling of complex industrial structures, and performing other activities to visualize and model the 3D scan.
Enterprises increasingly use 3D solutions leading vendors such as Autodesk, AVEVA, Bentley, ESRI and Intergraph to incorporate scans for the design, engineering and project management of industrial management. The leading enterprises that use these technologies are players primarily in the oil, gas and energy industries.
Prior to the design of the reconstruction of an object, it is critical to collect complete and accurate spatial data, capturing the actual geometry of the reconstruction object along with all of its components. This has been common practice in the past. Many designers still recall with horror the complex and very involved phases of collecting factual information. In order to execute the precise measurements of existing construction, dozens of people spent months and in some cases years working with tape measures, theodolites and ropes doing manual measurements of steel production plants. This resulted in a lot of human error, endless inconsistencies and continuous verification and correction. And now the advance of three-dimensional laser scanning technology has allowed completion of this first phase of on-site survey within significantly shorter periods of time and with an unprecedented increase in the quality, accuracy and detail of such work.
Using this new technology in the object survey phase of the project, a designer receives an accurate computer copy of the real object in the form of a three-dimensional model. And dozens of workers that were previously doing this work manually are easily replaced with only one instrument, operated by one operator. Moreover, all these measurements are performed without any contact between the operator and the object, so the process of measurement does not prevent the plant from continuing to conduct its business as usual. Such measurements at the TogliattiKauchuk plant was carried out by laser scanner FARO Laser Scanner Focus-3D and Leica ScanStation C10.
The Leica SS C10 scanner has a high range (up to 300m) and was used for scaled surveying and for scans registration with local coordinate system of plant. FARO LS Focus-3D scanners were used for detailed surveying of objects.
The Leica SS C10 scanner has the best indices while industry laser scanning on the distance more 40m, and has a good signal/noise ratio. The main advantage of Leica SS C10 is that it mounts on standard geodesic tripod with trigger, has built-in centering, double-axis inclination compensator, accepts a standard GPS antenna and has automatic recognition of flat geodesic tags.
The portability of Focus 3D Scanner allowed the crew to quickly transport the scanner from one surveying station to another without having to turn it off. This scanner has proved to be extremely adaptable when working within tight spaces and crowded conditions (lots of pipes, valves, flanges and steel in a confined space). Its small and efficient battery allowed continuous operation for up to 5 hours. The Russian interface of the internal firmware of Focus 3D laser scanner allows any operator to quickly and properly configure the device, and be confident that the desired result will be achieved.
The field work of the scanning of the plant was carried out by a team of four specialists in 34 working days, and consisted of two parts:
The work was carried out on an area of 5 hectares. However, multi-level interlocking of cables and tubes of different diameters, hundreds of technology setup areas, equipment, facilities, tanks and furnaces increased the technological complexity of the object and its scanning. Shooting conditions were close to extreme: functioning harmful production process, vibration, noise, high temperature piping, the presence of high- pressure steam, harmful chemical emissions, etc.
All elements of the object were subject to scanning, including each flange. Scanning was done from a total of 8,158 positions to achieve the maximum coverage of the elements of the measurement object. The total number of single measurements (in the point cloud) exceeded 12.5 billion. In order to reduce the time, in which this field phase of work was completed, the technology approach of “total scan” was used. The use of a standard survey methods (the use of the order of 7 spheres or marks on each scan) and stitching of such a large amount of data would have required 5-6 times more time. Additionally, the use of proprietary software allowed to successfully solve the problem of compensation for fluctuations and vibrations.
The postprocessing phase consisted of the following:
We used software Leica Cyclone 7.3.3 64-bit for final merging of aligned scans. The advantage of Leica Cyclone version 64-bit is to use all available RAM (we had RAM 128Gb). Unlike analogous software Leica Cyclone works faster and more correctly with huge point clouds: visualize, registration quality control, merge point clouds, cut clouds by parts to pass it to modelers.It should be noted that the final cloud of points contains not only the structure of the scan but also the transformations of the scans that have taken place during the alignment process in Leica Cyclone. If necessary, this alignment can be re-registered and transformed into a different coordinate system, where new elements of related objects can be added (for example in the case of continuing reconstruction work at the factory).The final 3D scan included every single one of the 12.5 billion real measurements that were captured during the scanning process. The customer got thin point clouds too to load it to AVEVA LFM for control. That data are in correct PTX format.
Quality control is performed by visual analysis of cross-linked sections of the cloud of points in the software environment Leica Cyclone. Horizontal and vertical cross sections of the aligned point models have been built in order to assess the accuracy of the models. The points in these cross sections were highlighted in different colors that correspond to the various scanning stations. The quality control inspection results were positive: the maximum difference between the points of scans from different stations amounted to 12 mm compared with the desired tolerance of up to 15 mm in the assignment specification.
The high density of the cloud of points and the adequate coverage of the element measurements enabled the successful deciphering and modeling of the details of the object according to the required specifications. 3D modeling was performed by different software: Bentley MicroStation, Autodesk AutoCAD and Leica Cyclone. This process consisted of inserting vector geometric basics into the appropriate segmented point clouds. The final collecting and checking of 3D models was done in Bentley MicroStation.
The final step was the quality control process to determine the quality of the output results. Together, this provided for an exact match between the executed model and the real measurements of the object. Thanks to complex and flexible tools of MicroStation a 3D model of 3D models was collected from other software. Powerful 3D visualizing and rendering created the final 3D model.
The entire project was completed within 102 working days. The project management team received a database in Leica Cyclone IMP-format, containing the normalized cloud of points along with credible 3D models of the plant in CAD and PDMS format within the coordinate system of the plant. Thanks to laser scanning and 3D modeling, the project for the modernization of the plant will be implemented with the highest quality.
About the author: Vladimir Semykin of 3DLS in Moscow, Russia; e-mail: sva at 3dls.ru