Tian Ailing1£¬Tomoaki Makihata2£¬Mitsuo Takeda2£¬Jiang Zhuangde1
(1.State Key Laboratory for Manufacturing Systems Engineering,Xi'an Jiaotong¡¡University,Xi'an 710049,China;2.Department of Information and Communication Engineering,The University of Elecro-Communications,Tokyo 182-8585,Japan)
Abstract:A threeª²dimensional profile measurement technique for objects with spatially isolated surfaces is presented,which is combined flexibly with temporal phase unwrapping based on the Fourier fringe analysis.A sequence of sinusoidal fringe patterns with a varying pitch over time is projected onto objects,and the temporal variation of the fringe signal is recorded with charge coupled device£¨CCD£© camera.The phase of the temporal fringe signal is detected at each pixel by Fourier transform method£¬ and is temporally phase unwrapped,independently from other pixels.The temporal frequency of the fringe signal estimated from the time slope of the unwrapped phase provides the information of the absolute surface heights of the objects.The measurement technique of objects with large discontinuities and spatially isolated surfaces is demonstrated by experiment.
Keywords:temporal phase unwrapping;Fourier transform;three-dimensional profile measurement;fringe pattern projection