Wheel profile and tread surface defect detection based on phase measuring profilometry

With the rapid development of high-speed and heavy-load in modern rail transit, the abrasion and surface defect of wheel tread are getting serious, and the demand of measuring the wheel profile and tread surface defect has been increasing. Phase Measuring Profilometry (PMP), due to its good characters of non-contact, high precision, easy to control automatically etc., is often used for precise 3D shape reconstruction. In this paper, PMP technology and Stoilov phase shift algorithm are adopted, three deformed fringe patterns of wheel are collected with fixed phase shift between them, and branch cut phase unwrapping algorithm is used, based on which the three-dimensional surface shape of the wheel is reconstructed and the artificial surface flaws on the tread are restored and measured. This method provides a good reference for the precise online detection of the wheel abrasion and surface defect.