In the world of Metrology, manufacturers are embracing technologies that boost accuracy, speed, and ultimately productivity both in their inspection and reverse engineering processes. White-light is a popular new technology to meet these objectives. Non-contact 3-D digital measurement machines are a way to meet manufacturing objectives in a way conventional coordinate measuring machines (CMMs) do not.
White-light structural lighting method creates an truly accurate, dense point cloud of a product. Light from two point sources are employed to illuminate an object with an interference fringe pattern. A CCD camera records the curvature of the fringes from a viewpoint offset from the projector by typically 20-30 degrees. The curvature of the fringe pattern, angle between the lights and camera enable the product surface to be computed and measured.
Once the measurements are computed a “patch” is formed. On average a patch consists of an 8”x 8” area. The total number of points measured in one patch can total 100,000 or more per second with an accuracy of about .002” or .05mm. These numbers are astounding compared to a CMM's capacity to measure about one point per second. Patches are created and merged until the user has enough critical information on their product.
