Fast and accurate fringe projection based on a MEMS microvibration mirror

In the traditional fringe projection technique, the speed of projecting 8-bit sinusoidal fringe patterns is slow. To address this issue, this paper designs a novel high-speed MEMS projector by using its high-frequency resonant and forward-reverse scanning. In high-speed projection mode, light sources may be unstable and produce more light-intensity noise. To reduce the standard deviation of phase errors, this paper proposes a method of generating high-quality sinusoidal fringe patterns. The proposed method encodes the traditional fringe pattern into the phase of the sinusoidal fringe pattern. Therefore, from a mathematical expression perspective, the actual projection pattern is a composition of two sine functions. The proposed method uses multiple projected patterns to computationally generate a high-quality phase-shifting pattern. Subsequently, the high-accuracy phase can be solved by using a phase-shifting method to process these generated high-quality phase-shifting patterns. Finally, the experimental results demonstrate the feasibility of the self-developed MEMS projector and the robust noise resistance of the proposed method. Compared to the traditional phase-shifting method, the proposed method can significantly improve phase accuracy in the case of the same required number of images.