Piezoelectric MEMS mirror based SPAD LiDAR system enabling real-time monitoring across large covered areas for smart factory applications

This paper presents a MEMS mirror based SPAD LiDAR system that monitors the surrounding in smart factories. The proposed LiDAR system enables safety monitoring in real-time by acquiring spatial and depth information of the region of interest in a production scenario where workers and machines coexist. This sensor system features a MEMS mirror using piezoelectric material AlN and wafer-level packaging that steers the diverged laser beam with a wavelength of 915 nm for a large field of view. In addition, a CMOS based SPAD pixel array is deployed to detect the target region and thus the improved detector performance can be achieved. This study includes the lens system design for an effective LiDAR illumination part and the evaluation results of real-time object and human detection with the prototype LiDAR sensor system.