Vol. 42, Issue 1, pp. 31-41 (2012)
Keywords
on-line inspection, phase measuring profilometry (PMP), Stoilov’s algorithm, pixel matching, modulation
Abstract
An on-line phase measuring profilometry (PMP) based on Stoilov’s algorithm which can be used for on-line 3-D shape inspection is proposed in this paper. A stationary sinusoidal grayscale fringe pattern is projected onto the object kept on the production line, and an immobile charge-coupled device (CCD) is used to capture five deformed patterns equidistantly. The phase distribution is calculated by using Stoilov’s algorithm, and the height distribution of the inspected object is obtained through the relation of phase–height mapping. When inspected object moves, the positions of images in different deformed patterns change, so the pixel matching is implemented to acquire the equivalent phase-shifting which meets the requirement of Stoilov’s algorithm. Modulation which represents the contour of inspected object is used as the template to perform the pixel matching for the first time in this paper. Computer simulation and experiment verified the effectiveness of the method.