Well, What is it? Terrestrial laser scanning (TLS) is a form of measuring with a tripod-based LIDAR (light detection and ranging) instrument used to capture high accuracy data of buildings and other objects.
What is it used for?
TLS is used for a large variety of different applications, including capturing the flatness of a wall, preserve the conditions of a crime scene or accident, document the faꞔade of a large building for pre-fab architectural paneling, analyzing the shape of a vessel, volumetric stockpile surveys and many more.
Leica Scanner at a Bridge
How does it work?
Terrestrial Laser Scanners works by emitting an invisible laser to measure 3D points the same as a survey total station would. The difference is the scanner’s ability to measure its entire scene and the speed at which the measurements are taken.
The laser field of view is 310 degrees vertically and 360 degrees horizontally. The laser scanner will rotate upon the tripod and spin the mirror at the same time to capture the full scene. Each scan takes about 3-7 minutes, depending on the resolution.
What Does a Terrestrial Laser Scanner measure?
Terrestrial Laser Scanners measure everything in the line-of-sight of the laser. The smallest details like the texture of brick, the leaves on trees, and the metalwork of ornate hand-railings are picked up in the scans.
Scan of a museum
What is the accuracy of the Terrestrial laser scanner? Is it any better than a pro-3D camera?
Absolutely, terrestrial laser scanners can measure points as accurate as 3mm at 30 feet. A standard pro-3D camera cannot achieve less than an inch of accuracy. The resulting “point clouds” from the scanner are extremely high-resolution with points in spaced very close together, so close that the result of a scan looks just like a photograph.
The higher the resolution the slower the scanner will rotate making the resulting point cloud more detailed. The faster the scanner rotates the less time the laser has to document to small changes creating a lighter point cloud.
The Resolution of the scanner does not always directly affect the resolution of the “project point cloud”. For example, scanning a single wall with a handful of low resolution scans the resulting point cloud will be a higher resolution because of the number of points that accumulate from more than one low res scan.
Grey-scale Factory Scan
Color or Black and White?
Depending on the need or conditions of the project, laser scanning can be conducted in absolutely no light. This makes it possible to measure and see things in places of absolute darkness. When scanning in dark conditions, the scanner is unable to pick up color unless artificial light is added, but the resulting point cloud imagery looks almost like night vision. Everything that was once very dark will be brightly visible in the 3D imaginary.
What are the benefits of using terrestrial laser scanning?
Benefits in Architecture
Capture the “as-is” conditions of a building quickly, accurately, and with little to no disruption. Photorealistic imaging and 3D visualization of different aspects of buildings to create views never seen before. 3D data can be used in all common CAD programs. FARO WebShare Cloud for sharing the scan data via the internet simple, secure, and can be used anywhere online. The resulting point clouds can be precisely modeled in Autodesk Revit.
3D modeling and laser scanning of a historic fountain
Benefits in Construction
Laser Scanning in construction can offer fast and cost-effective documentation of the entire construction process. Seamless capture and monitoring is critical for construction progress for legal and technical documentation, precise dimensional check of complex components such as free-form shape elements, documentation of deformation processes and monitoring of countermeasures., project coordination to help improved multi-trade project collaboration. Capturing scans at all phases of construction can aid in the case of final building inspections by being able to go back and visualize the entire construction process start to finish.
Structural Steel Clash Detection
Benefits in Property Management & Facility Maintenance
Building information models (BIM) is taken another step further here at PMC. We interject valuable asset information right into the living model. This way your facility can be on the cutting edge of maintenance and efficiency by utilizing autonomous features right through the model.
3D Laser Part Scanning is a non-contact, nondestructive technology that digitally captures the shape of physical objects using a line of laser light. Point clouds are then created by data obtained from the laser surface scan of an object, which allows the capture of a physical object’s exact size and shape into the computer world as a digital 3-dimensional representation. 3D scanning technology also makes it easier to generate feature-created models and accurately dimensioned 2D CAD designs. This differentiates the process from built as-modeling, where a CAD operator purposely drafts a model to reflect any defects of the part that is under study.
Laser Part Scanning
3D Laser Scanning is a non-contact, nondestructive technology that digitally captures the shape of physical objects using a line of laser light. 3D laser scanners create “point clouds” of data from the surface of an object, which allows the capture of a physical object’s exact size and shape into the computer world as a digital 3-dimensional representation.
Our engineers understand all phases of the manufacturing process. From prototyping to production, we can help you identify where problems may originate. Our detailed reports reveal exactly where deviations exist, saving time and money over manual inspection techniques.
As the drive to increase efficiency and reduce rework for factory planning continues to grow many factory owners look to 3D factory design to help. This leads to the question, how do I get my factory into to 3D?
Getting the 3D Data
The first step in getting a 3D factory is gathering the 3D information. Traditionally this was done using manual measurement techniques. More recently this work has been almost entirely replaced by laser scanning. The reason for this shift is two fold; first the cost per square foot has dramatically reduced while the quality of the data has increased by over 10x. These two factors have lead to a dramatic shift in data acquisition since 2010.
Not Apples to Apples
Even though scanning now cost less the data being collected is far superior to that which is collected through manual means. The scanner does not miss or forget dimensions. The scanner also collects information that simply is not reasonable to collect through manual means.
Although it is possible to model your factory in any application from Catia to AutoCAD you will get the most out of your model by using specialized factory design applications. Currently there are two dominant applications in 3D factory design, Siemens FactoryCAD and Autodesk Factory Design Suite.
Siemens FactoryCAD The first 3D factory tool to hit the market FactoryCAD is a full featured AutoCAD add-on similar
to many other applications such as AutoCAD MEP. FactoryCAD features many pre-made systems covering most assets typically found in factories such mezzanines and cranes to material handling containers and operators.
Autodesk Factory Design Suite
It is now possible to develop 3D models to any LOD in almost any format. Although some automated tools exist most model geometry is still created using tracing techniques. Cost effective options of generating 3D models typically involve having portions of the model completed by overseas partners.
As teams become more sophisticated laser scan users they’ll start to find new a creative uses for the scan data that don’t always involve modeling. Scan data can be edited to remove objects that will be demolished right within the cloud itself. The scans can also be plotted directly on sheets for use by installers and fabricators.
If you decided to convert your scan data to model data one of the most important decisions you’ll make is what LOD should you’re model be developed to. Within the AEC industry today even LOD has multiple definitions. It can either stand for Level of Detail or Level of Development. These are two distinct things. Level of Detail is purely a CAD modeling visualization decision. Will generic objects be used within the model or will the exact item be modeled? Level of Development, sometimes called Level of Design refers to the models development as it pertains to it use in construction of the building. This has little to do with the visual representation of the objects in the model and has more to do with the data behind the objects. For example if a model is in an LOD500 state it will contain warranty information for each item.
3D Laser Scanning is a non-contact, non-destructive technology that digitally captures the shape of physical objects using laser light. 3D laser scanners create “point clouds” of data by scanning over them with laser light. In other words, 3D laser scanning is a way to capture a physical object’s exact size and shape into the computer world as a digital 3-dimensional representation.
Getting the 3D Data
The first step in getting a 3D building is gathering the 3D information. Traditionally this was done using manual measurement techniques. More recently this work has been almost entirely replaced by laser scanning. The reason for this shift is two fold; first the cost per square foot has dramatically reduced while the quality of the data has increased by over 10x. These two factors have lead to a dramatic shift in data acquisition since 2010.
For most projects a single scanner is used. A modern scanner is a small piece of equipment that sits on top of a standard camera tripod. The scanner will be setup multiple times throughout the building or facility to be scanned. Depending on the project size you should expect to see anywhere from 20 to over 1000 individual setups. Each time the scanner is run it will take from 2 to 10 minutes depending on the settings used.
The shape of objects appear as millions, or even billions, of points called a “point cloud”. The point cloud is viewed on and processed on standard workstation class computers. The process is very fast, gathering up to 1,000,000 points per second and very precise over large areas (to ±0.12″). Scan data is commonly used in most major CAD applications including all Autodesk and Bentley products. The scan is used as a reference to create model geometry for use in project planning or sometimes just on it’s own as an accurate record of as-built conditions.
Laser Scanning Process ROI
Accurate and exact measurements
All data is captured
Advanced decision making
Data is quickly available to entire team
Reduce costs and schedule savings
Reduce job site interruption
More Than a Planning Tool
One common use within the AEC industry is to ensure that what was promised is what was delivered. This can be used a various stages of construction to accomplish different goals. It is often used a quality check to ensure that installers are meeting there obligations to ‘build to the model’. Another great use is to capture conditions before they are enclosed. Have a 3D scan of piping before it is encased in concrete can be a great asset for a building owner to posses.
PMC is the largest independent industrial engineering & simulation services firm in North America. For over 30 years PMC has been leveraging the latest in advanced technology to improve our Client’s processes. Established in 1979 PMC, has grown to have office around the world. With over 700 clients, 6000 completed projects, and over 150 employees PMC can work with you to find the right data-driven productivity solutions for your needs.