Laser stands for optical amplification excited by radiation. 3D laser scanning uses a laser beam to scan a part. There are several types of laser scanners, but the most common are: hand-held, where the beam is swept across the part and mounted on a tripod, and the laser line sweeps over an area or measures a point. The scanner can also be attached to an arm or a traditional gantry, but sometimes restricts scanning to a limited size, which increases the risk of human error and introduces a degree of uncertainty to the measurement.
3D scanning solutions using structured light are a fast, highly accurate and non-destructive way to digitally capture the physical form of an object. Much like laser scanning, digital data captured through 3D scanning can be used for product design, visualization, and inspection to help design engineers with quality assurance, design modifications, and improvements.
(1) Data output
Both laser scanners and 3D laser scanning technologies can produce high-density point clouds or polygon meshes, which can be inspected directly into CAD models, geometry or manufacturing drawings, or older products can be reverse-engineered using specialized software.
(2) Accuracy and traceability
Once the line passes through the illuminated object, the laser scanner captures the data. The 3D scanner samples the data multiple times as the fringe pattern of varying width and phase captures the shape of the object. 3D laser scanning technology is inherently more accurate than laser scanners due to the repeatability, traceability and high resolution of measurements. Both systems are immune to ambient light conditions, and both types of systems are suitable for industrial applications. Because 3D scanning provides greater accuracy, it is especially useful for measuring very detailed projects, capturing the defining edges of a part. As such, 3D is the preferred data capture method for the aerospace and power generation industries for its high level of accuracy, resolution and full traceability of data.
One of the biggest differences between laser scanners and 3D laser scanning technology is the light intensity used. Laser scanners focus intense light and energy into a small area, so the biggest safety hazard associated with this is eye safety. Technology cannot project with the same intensity and therefore does not carry the same risks. This makes 3D technology easy to implement in a wide range of environments, as it presents minimal security concerns when used in open studios or design studios.
(4) Potential scanning area
With the added benefit of using a photogrammetric system, it is possible to expand the potential scan area where we are using the system without compromising the accuracy of the scan data. Photogrammetry is a stand-alone metrology system designed to capture reference points using multiple digital images using a validated camera. The system can use these reference points to expand the potential scan area, which means large objects can be captured. Most laser scanners do not have the capability to integrate with photogrammetry or other single point systems, which means that accuracy can be compromised when scanning large objects.