High resolution laser fringe pattern projection based on MEMS micro-vibration mirror scanning for 3D measurement

Abstract

3D measurement of micro-sized components by Fringe projection profilometry (FFP) requires fringe patterns with high spatial resolution. In order to project high-resolution and fine fringe patterns, a MEMS scanning module is used to project the precise time-modulated line laser stripes into space to form high-resolution laser fringes. The micro-vibration mirror in the MEMS module works in a resonant state, and the internal position detection of the MEMS module generate precise time reference signal. The reference signal is used to project spatial fringe patterns and ensure the stability and high resolution. The high-resolution laser fringe patterns generated by MEMS scanning module are projected to micro-sized components for 3D measurement. The measurement experiment shows that the spatial resolution of the projected fringes can reach 0.47 mm and the phase shift resolution is 0.12 mm. The measurement results show that the tiny height changes of the measured components can be well measured and presented. The standard gauge block with a height of 1 mm is measured, and the root mean square error of the measured height is 0.037 mm. It has a good prospect to apply the proposed method to the 3D measurement of micro-sized components.