2D LiDAR

A spinning laser rangefinder that scans one horizontal plane, measuring the distance to obstacles all around.

A 2D lidar, also called a single-line lidar, has just one laser beam for ranging, spun by a motor or a rotating mirror to sweep out a horizontal plane; each revolution outputs a series of angle-and-distance readings that, plotted together, trace an outline of the surroundings. Ranging is done by time-of-flight (d = c·t / 2, where c is the speed of light and t is the round-trip time), though cheaper units use triangulation instead. Being cheap, low in data volume, and stable in precision, 2D lidars are common in robot vacuums, warehouse AMRs, and AGVs, used for 2D lidar SLAM, AMCL localization, and obstacle avoidance; ROS represents their data with the LaserScan message. Their limitation is that they only see the single plane at their mounting height, so obstacles like tabletops or overhead bars that sit outside that plane get missed, requiring a depth camera or a multi-line lidar to fill the gap.

ExampleThe Slamtec RPLIDAR A1 performs a 360° scan, ranging more than 8,000 times per second at an adjustable 2–10 Hz scan rate using triangulation, and is officially positioned for SLAM mapping, robot navigation, and robot vacuums.

Also called

Single-Line Laser Scanner, Laser Scanner, Planar LiDAR

Related

LiDAR · LiDAR SLAM · Adaptive Monte Carlo Localization · Occupancy Grid Map · Costmap · Robot Vacuum Cleaner

Sources

SLAMTEC RPLIDAR A1
Wikipedia: Lidar