New approach to improve the accuracy of 3-D shape measurement of moving object using phase shifting profilometry

When phase shifting profilometry (PSP) is employed for 3-D shape measurement, the object must be kept static during the projection and acquisition of the multiple fringe patterns. Errors will occur when the object moves and if the projection and capture of fringe patterns are not fast enough. In this paper, a new approach is proposed to tackle the problem, consisting of two steps. Firstly, the rotation matrix and translation vector describing the movement of the object are estimated using a set of marks placing on the surface of the object. Then the expressions of the fringe patterns under the influence of 2-D object movement are derived, which are employed to determine the correct phase map, leading to accurate measurement of the profile. Simulations and experiments are presented to verify the effectiveness of the proposed algorithm.