Lissajous-Like Scan Pattern for a Nodding Multi-Beam Lidar

Abstract

In this paper, trajectory design for a nodding multi-beam Lidar system is studied. While the multi-beam Lidar is inherently 3-dimensional and does not require nodding to create a 3D scan, the vertical resolution of these units can be limited, depending on the number of Lidar beams and their spread. This is especially important when viewing small objects and objects at distance. This vertical resolution can be improved by placing the Lidar on a nodding mechanism, allowing the beams to be repositioned. Typically, this mechansism undergoes a raster scan pattern, where the Lidar is slowly rotated and each line of Lidar data is collected in order. In contrast, this work presents the use of Lissajous-like scan pattern, in which the depth points are collected while the cradle is moving quickly. This trajectory allows for a trade-off between scan speed and resolution that is not possible when using a raster scan. In this paper, relevant theory and prior work is presented, simulations are shown that support the proposed theory, and proof-of-concept experiments are performed to show the feasibility of the approach.