A Miniature LiDAR With a Detached MEMS Scanner for Micro-Robotics

Abstract

Light detection and ranging (LiDAR) has been widely used for airborne surveillance and autonomous driving. The ability of robotics or even micro-robotics can be drastically enhanced if equipped with LiDAR, but very light and small LiDAR must be used. Micro-robots have sizes close to birds or insects, and almost all existing LiDAR are too heavy and too large for them. In this work, a novel MEMS LiDAR, with its optical scanner separated from its base, is proposed and demonstrated. The scanner head will be carried by a moving micro-robot while the LiDAR base is fixed on the ground. There is a thin, flexible optical/electrical cable connecting the scanner head to the base. The scanner head consists of a MEMS mirror and a rod lens, which weighs only 10 g and measures under 4 cm long. The MEMS mirror has an aperture of 1.2 mm <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times \,\,1.4$ </tex-math></inline-formula> mm and can scan a field of view (FoV) of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$9^{\circ } \times 8^{\circ }$ </tex-math></inline-formula> . As the micro-robot and the optical scanner head moves with respect to the optical receiver, an IMU (inertial measurement unit) has been embedded in the scanner head to track the motion and an algorithm has been developed to reconstruct the true point clouds. The movable head LiDAR can acquire 400 points per second and detect targets up to 35 cm away. A micro-robot can carry the scanner head while it is moving, and the point clouds can be generated at the LiDAR base. This new LiDAR configuration enables ranging, mapping, tracking, and zoom-in scanning for micro-robots.