System integration of hybrid assembled large aperture Micro Scanner Array for fast scanning LiDAR sensors

Abstract

We present the design and system integration of a hybrid MEMS scanning mirror (MSM) array developed for real-time three-dimensional imaging with a panoramic optical field of view (FOV) of 360 deg ×60 deg (horizontal × vertical). The pulsed time-of-flight light detection and ranging (LiDAR) system targets a distance measurement range of 100 m with a video-like frame rate of 10 Hz. The fast vertical scan axis is realized by a synchronous scanning MSM array with large receiver aperture. It increases the scanning rate to 3200 Hz, which is four times faster in comparison with state-of-the-art fast macroscopic polygon scanning systems used in current LiDAR systems. A hybrid assembly of frequency selected scanner elements was chosen instead of a monolithic MEMS array to guaranty high yield of MEMS fabrication and a synchronous operation of all resonant MEMS elements at 1600 Hz with large FOV of 60 deg. The hybrid MSM array consists of a separate emitting mirror for laser scanning of the target and 22 reception elements resulting in a large reception aperture of D eff ¼ 23 mm. All MSM are driven in parametric resonance to enable a fully synchronized operation of all individual MEMS scanner elements. Therefore, piezoresistive position sensors are integrated inside the MEMS chip, used for position feedback of the driving control. We focus on the MEMS system integration including the microassembly of multiple MEMS scanning elements using micromechanical self-alignment. We present technical details to meet the narrow tolerance budgets for (i) microassembly and (ii) synchronous driving of multiple MEMS scanner elements. © The Authors. Published by SPIE under a Creative Commons Attribution 4.0 International License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.

Unlocking The Potential of Lidar: Principles, Applications, And Future Prospects

“…As mirror routes, the scanning system can scan and collect the data on s straight line. And owning to the rotation of the beam system, which is the cylindrical part in the figure below, the device can 360-degree scan the surroundings through horizontally route the scanning line [3].…”

“…Fig. 1 Structure of Mechanical scanning LiDAR [3] Mechanical lidar has fast scanning speed and strong anti-interference ability. However, mechanical lidar relies on the rotation of the mechanical structure to realize scanning, which has the disadvantages of severe physical wear, high cost, and bulky volume.…”