It is a non-contact metrology technique used to measure the three-dimensional surface topography of an object. To achieve that, the measurement is obtained by capturing a series of projected sinusoidal patterns on the surface of interest. The key advantage of fringe projection is its ability to capture the detailed information of the surface quickly and non-destructively.
HOW DOES FRINGE PROJECTION WORK?
It operates using the triangulation method, which projects a series of structured light patterns, typically sinusoidal or parallel fringes, onto the surface or sample and analyzes how these patterns are distorted by height variations.
Distortion of the projected fringes due to changes in surface height results in a phase shift.
Advanced algorithms interpret this phase data to generate highly detailed 3D coordinates, reconstructing the object’s surface with high precision.
A typical Fringe Projection system consists of:
A projector that emits light patterns on the sample’s surface.
A camera that is positioned at a known angle relative to the projector records the deformed patterns.
By analyzing these distortions, advanced algorithms compute precise 3D surface coordinates. The resulting dataset enables the reconstruction of highly detailed topographies, making Fringe Projection a powerful technique for accurate, non-contact 3D measurement.
This method is particularly effective for large-area measurements, offering high vertical resolution and repeatability for large-area and form measurements.
APPLICATIONS
Fringe Projection is commonly used for large-area measurements and complex geometries that require fast, non-contact 3D surface reconstruction. It enables rapid measurement of surfaces ranging from millimeter-scale components to much larger objects.
Because of this large measurement field and fast acquisition, this technique is typically used when the inspection area exceeds the range of microscopic techniques such as Interferometry or Confocal microscopy, making it particularly suitable for macro-scale surface characterization.
Typical applications include:
Industrial inspection: Quality control of large or complex components.
Advanced manufacturing: Monitoring machining, additive manufacturing, and tooling processes.
Cultural heritage: 3D digitization of artifacts and historical objects without physical contact.
Medical and dental fields: Measurement of implants, prosthetics, and anatomical models with complex geometries.
Materials science: Characterization of surfaces and novel materials with high vertical accuracy.
