Application of FTP in flaw detection of rail web

In this paper, the author aims to use the Fourier transform profilometry(FTP), a three-dimensional non-contact optical measurement method, for recovering the rail profile and defects on the rail web. In phase unwrapping, the least square algorithm based on the specific characteristic of the rail is used. Simulation is done to manifest the feasibility of the method. Results of the experiments show that in restoring the rail profile and detecting the rail web´s defects FTP have significant advantages, the simulation shows that the maximal error of the algorithm is 0.053mm, compared to some traditional surface detection method, it is able to achieve a higher accuracy, also provides a better basis and testing demonstration for the further application of the non-contact optical three-dimension measuring method on the rail.