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What is 3D laser scanning or 3D scanning?
3D laser scanning is a method of non-contact measurement of the shapes and colour of the surface of an object to create a computer replica.
It is one of the many specializations of topography. Different tools can be used like a camera, LiDAR, or a 3D laser scanner.
More precisely, 3D scanning technology by laser or remote sensing is the process of measuring an environment using a 3D laser scanner or a LiDAR.
The data resulting from the digitization provide a virtual representation of reality in the form of a three-dimensional (XYZ) point cloud, whether colorized or not.
From the creation of databases to preventive maintenance, through technical expertise or the integration of projects in complex environments such as industrial factories, 3D digitization is emerging as the technology that is revolutionizing topography.
Pipetech Engineering uses two different technologies: 3D laser scanner and LiDAR.
The first is a static measuring device that needs to be moved as many times as necessary to obtain complete digitization of the area of interest.
The second is dynamic, onboard a vehicle, drone, or helicopter, it collects data by following a defined trajectory.
How to successfully integrate 3D laser scanning into your business? What is important to consider before investing? When to adopt 3D laser scanning?
Advantages and limitations of 3D laser scanning The advantages are numerous: Saving of time in the field -
measurements - Completeness of readings - Elimination of reading errors - Reduction of project-related
costs - Saving
of time and errors on engineering studies - Digital validation of a project - Night surveys possible
- Work survey and
roadway under track (no stopping road track).
The limits depend on the device (range and precision) and on the use which is made of it because the tool must always be adapted to obtain the desired result.
It should be noted that the processing of the data resulting from digitization requires the use of powerful and expensive professional software because the data acquisition represents only 20% of the work!
The structured light used for 3D laser scanning can be white or blue and generated by numerous types of projectors, such as Digital Light Processing (DLP) technology.
The main advantages of the structured light technology for 3D laser scanning are its speed, resolution, and ability to do 3D laser scanning of people. One downside of the structured light technology is its sensibility to light conditions and issues to work outside.
Photogrammetric technology is also capable of reconstructing subjects of various scales, photographed from the ground or from the air. One downside of the photogrammetry technology is its sensitivity to the resolution of the input photographs and the time it takes to run the algorithms.
What are the most common mistakes while integrating 3D laser scanning?
It is clear that while investing in new technology, knowing the most common mistakes can prevent them from being made in the future.
Another way to prevent these problems is to have some knowledge of metrology, which makes the filtering process easier, as well as extracting the elements of the point cloud once it has been filtered and meshed.
The accuracy of the scanners and the part material could be one of the most common limitations.
" Today, in most cases, the precision provided by a contact system is a little greater than what a scanner can offer us. Another limitation that we may encounter is the material shine of the piece, as in some cases we will need outside help to mattify the surface and get a quality cloud. "
The two typical errors are generally the measurement time and the cost of a 3D laser scanning: “ Users who are not familiar with this technology think that by scanning a 3D object, this geometry can be easily modified.
This reverse engineering process is not an immediate process and requires some expertise to get a quality scan many users consider the result of the 3D data obtained by scanning to be equivalent to the original 3D digital model file.
“ The scanned point cloud or mesh data file is different from the original 3D digital model. Users need to undergo professional training to convert the mesh data le to a 3D digital model file. "
What should you consider before investing in 3D laser scanning technology?
Photo by zero take on Unsplash
The technology laser triangulation works by projecting a point or a laser line on an object, then capturing the reaction using sensors. This method is called triangulation because the laser point (or line), the sensor, and the laser emitter form a triangle.
On the other hand, structured light also uses trigonometric triangulation, but it works by projecting a pattern of light onto the object to be scanned and not a laser line (or point).
These two technologies are the most important today, with their advantages and disadvantages that should be known.
With these concepts in mind, let's find out what the experts think about which method to use in each case.
“In recent years, both solutions have been continuously improved.
Laser triangulation has certain advantages: when it requires precision and speed of measurement, it can achieve much better values than structured light.
In addition, it tends to create less noise on parts with refraction or reaction.
In the case of structured light, we have the advantage of being able to cover a larger working area, which makes it easier to measure large objects.
Laser triangulation scanners are normally more accurate than those for structured light, although capturing is generally longer and more complex.
It is common to use structured light on large parts and lasers on parts with tighter tolerances, but this should be evaluated in each case. "
3D laser scanning services can make the link between existing unknown conditions and complete documentation.
Having accurate data makes it possible to plan projects without having to deal with unknown interference and conflicts.
Range of Applications as designed for 3D laser scanning