Producing 3D CAD Models from Laser Scanning Data
Laser scan surveys are conducted for the purpose of performing retro-fits and upgrades to piping, processing plants, offshore facilities and vessels such as FPSOs. CAD models generated by laser scan surveys allow piping engineers and designers to make necessary changes in a safe environment, with the knowledge that new parts will fit in the desired location on the initial installation. Please click for more information.
19 April 2016
Intertek Surveying Services is a global leader in the field of dimensional control, surveying and laser scanning. With hubs in Australia, Brazil, Canada, UK and USA, Intertek has established a reputation as a trusted measurement partner with a focus on proactive, process-driven dimensional control management. Intertek has executed significant onshore and offshore projects for blue-chip clients around the globe.
Why laser scan?
Generally speaking, laser scan surveys for the oil and gas industry are conducted for the purpose of performing retro-fits or upgrades to piping and machinery at processing plants or facilities and offshore facilities or vessels such as FPSOs. The end goal is to produce a CAD model which piping engineers or designers can make necessary changes safely, with the knowledge that when the new part or parts arrive on site that they will fit in the desired location on the initial installation. In other instances there may be no plans or drawings of the facility and laser scanning is deployed to complete an as-build survey of the site. This gives engineers and designers the insight they need to plan for future work or maintenance programs. Laser scanning captures the geometry of the existing piping accurately and in very high detail, allowing this information to be used in the design process.
Figure 1: Laser scan point cloud data with resulting CAD modelling overlaid.
Converting the point cloud data to a CAD model
Converting the raw laser scan point cloud data into a CAD model requires specialised software that can turn millions of 3D points measured on the piping into solid CAD models. Intertek Surveying Services is a global distributor of the LFM suite of laser scan software and experts in producing CAD models from laser scan data. Using LFM Intertek can quickly produce CAD models and export them to a variety of CAD packages to suit our clients’ needs.
Geometric or intelligent CAD models?
There are two types of CAD models produced from laser scan data, simple geometric models and intelligent models. A geometric model is the basic shape of the pipe or flange with a centreline. The LFM software analyses thousands of points on the pipe and precisely fits a CAD element to them with millimetre accuracy. The resulting pipe model only contains basic geometry such as the diameter and length of the pipe.
Intelligent models are similar to geometric models, however, when analysing the points to fit the CAD element the LFM software references international standards tables for piping such as ANSI for the type of pipe that best suits the data. When created, this model provides much more specific information such as the pressure rating for the pipe and what type of valves, flanges and other associated equipment are designed to work with it.
Figure 2: Standards tables in LFM
Intelligent models are then exported and carry this information with them. The additional information is particularly useful for Pipe Designers who can import the models into their native CAD packages. Armed with this additional information engineers and designers are able to work more efficiently, as opposed to being required to manually input this information when using a basic geometric model. Additionally, isometric drawings (ISOs) ISO’s can quickly be generated from intelligent models for fabrication shops to manufacture replacement components.
Stuart has been working in precise surveying, laser scanning and metrology for over 10 years in Australia, SE Asia and Africa. He has started-up the Australian operations for Intertek increasing our global reach to this region. Intertek Surveying Services (formerly Hi-Cad) are a global leader in dimensional control and laser scanning.