MULTIPARAMETER MEASUREMENT FOR RACEWAY GROOVE OF BEARING BASED ON 3D RECONSTRUCTION WITH DIGITAL STRUCTURED LIGHT

A fast 3D reconstruction method based on structured light to measure various parameters of theraceway groove is presented. Digital parallel grating stripes distributed with sine density are projected ontothe raceway groove by a DLP projector, and distorting of stripes is happened on the raceway. Simultane-ously, aided by three-step phase-shifting approach, three images covered by different stripes are obtained bya high-resolution CCD camera at the same location, thus a more accuracy local topography can be obtained.And then the bearing is rotated on a high precision computer controlled rotational stage. Three images arealso obtained as the former step at next planned location triggered by the motor. After one cycle, all imagesinformation is combined through the mosaics. As a result, the 3D information of raceway groove can begained. Not only geometric properties but also surface flaws can be extracted by software. A preliminaryhardware system has been built, with which some geometric parameters have been extracted from recon-structed local topography.