Fringe projection (also known as “fringe projection profilometry” or “digital fringe projection”) is a metrology technique used to create precise measurements of three-dimensional (3D) surfaces. It is a subset of structured light measurements, which includes other measurement techniques. A fringe projection system requires a camera and projector, which are offset from one other as seen in the left image below. An algorithm is used to triangulate the surface with a known distance to create a repeatable and calibratable measurement with known uncertainty.
In fringe projection, the measurement is created by capturing a series of projected sinusoidal patterns onto the surface of interest. The measured object creates what is known as a “phase offset,” which an algorithm uses to create the same repeatable and calibrated measurements with known uncertainty. The output is a measurement, in quantifiable units like microns, for the entire surface.
Fringe projection was pioneered in the late 20th century, revolutionizing ability to measure surfaces. The technique quickly became the industry standard for precise 3D surface analysis, such as manufacturing.
One of the key advantages of fringe projection is its ability to capture detailed surface information quickly and non-destructively. This makes the technique a valuable tool for industries which require precise measurements for quality control like aerospace, automotive, electronics, energy, and medical device manufacturing. Fringe projection systems are an objective inspection technology subject to industry standards, including ISO 25178 for surface texture, and ISO 16610 for metrology.
Today, at Phase3D, all our products use a patented customizable optics system which employs fringe projection to measure powder-based additive manufacturing builds. By using fringe projection the exact profile of every layer of every build is extracted and used to detect anomalies which lead to part defects. Phase3D has released Fringe Research to empower the additive manufacturing industry by measuring every layer, identifying build anomalies, and improving the build and part performance using real, objective data. Make sure to check out https://www.additivemonitoring.com/ to learn more.
