“MEMSEye” for optical 3D tracking and imaging applications

Abstract

We demonstrate a compact, low-power device which combines a laser source, a MEMS mirror, and photo-sensors to enable fast-motion tracking of an object in a 3D volume while obtaining its precise XYZ coordinates, as well as high resolution laser-based imaging. Any object can be tracked which is marked by retro-reflective tape, or a corner-cube retroreflector (CCR). Two separate subsystems which we termed “MEMSEyes” track the position of the object within a ∼40° field-of-view cone, allowing triangulation of the object's distance. A demonstration system running in a 40 kHz control loop is capable of human hand motion tracking and provides position information at up to 5m distance with 13-bit precision and repeatability. In another demonstration, a longer object is marked by two CCRs at its ends and the system measures its orientation in space with ∼0.1° precision by locating both ends (CCRs) in a time-multiplexed manner. When used in rastering mode, a single MEMSEye device can efficiently scan objects and 2D barcodes.