Resonant biaxial 7-mm MEMS mirror for omnidirectional scanning
Resonant biaxial 7-mm MEMS mirror for omnidirectional scanning
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DOI：
10.1117/1.jmm.13.1.011103
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发表时间：
2014-01-01
影响因子：
2
通讯作者：
Benecke, Wolfgang
中科院分区：
文献类型：
--
作者：
Hofmann, Ulrich;Aikio, Mika;Benecke, Wolfgang
需要用于环境感知的低成本汽车激光扫描仪，以便将先进的驾驶员辅助系统集成到所有汽车领域，这是减少道路交通事故数量的关键。在欧洲资助的MiniFaros项目范围内，来自五个不同国家的合作伙伴一直在合作开发小型低成本飞行时间测距传感器。基于全向透镜和双轴大孔径MEMS反射镜的组合，开发了全向360 °激光扫描概念。描述了一种由堆叠式垂直梳状驱动器静电致动的谐振双轴7 mm无框架MEMS反射镜的概念、设计、制造和首次测量结果。两个正交轴的相同谐振频率对于实现所需的圆扫描能力是必要的。选择了三脚架悬挂，因为它最大限度地减少了两个谐振轴的频率分裂。通过超过500微米的镜子厚度来实现低镜子曲率。已经开发了基于多晶片键合的这种大型反射镜的气密晶片级真空封装，以实现每个轴上+/-6.5度的大机械倾斜角。由于+/-15度的大目标倾斜角并且由于MEMS镜致动器具有10 mm的直径，已经实现了约1.6 mm的腔深度。(C)2014年，美国光电仪器工程师学会（SPIE）
Low-cost automotive laser scanners for environmental perception are needed to enable the integration of advanced driver assistant systems into all automotive vehicle segments, which is a key to reduce the number of traffic accidents on roads. Within the scope of the European-funded project MiniFaros, partners from five different countries have been cooperating in developing a small-sized low-cost time-of-flight-based range sensor. An omnidirectional 360-deg laser scanning concept has been developed based on the combination of an omnidirectional lens and a biaxial large aperture MEMS mirror. The concept, design, fabrication, and first measurement results of a resonant biaxial 7-mm gimbal-less MEMS mirror that is electrostatically actuated by stacked vertical comb drives is described. Identical resonant frequencies of the two orthogonal axes are necessary to enable the required circle scanning capability. A tripod suspension was chosen, since it minimizes the frequency splitting of the two resonant axes. Low-mirror curvature is achieved by a thickness of the mirror of more than 500 pm. Hermetic wafer-level vacuum packaging of such large mirrors based on multiple wafer bonding has been developed to enable a large mechanical tilt angle of +/- 6.5 deg in each axis. Due to the large targeted tilt angle of +/- 15 deg and because of the MEMS mirror actuator having a diameter of 10 mm, a cavity depth of about 1.6 mm has been realized. (C) 2014 Society of Photo-Optical Instrumentation Engineers (SPIE)