3D Point Cloud From Lidar Acrylic Box Acrylic Box for Experiment Acrylic Box Not Recognized Dynamic Object Detected by Radar 2D Map Generated by Lidar Acrylic Box Recognized IWR 1443 VLP-16 2D Map With Radar Detection (a) (b) VLP-16 RPLIDAR-A2 3D Point Cloud for Mapping and Localization 2D Scan for Aisle Detection Data Points From Wall-Penetrating Radar (c) (d) FIGURE 9. Application examples for combining lidar and radar sensors heterogeneously or homogeneously. (a) Human detection by radar sensors and its tracking on a 3D lidar point cloud map. The position of a detected human is shown in white. (b) A 2D map augmented by radar detection of acrylic objects. Acrylic boxes of the environment, lidar maps, and radar detection are presented in red. (c) Extended map generation by radar and 2D lidar sensors. Data points from the lidar and radar sensors are depicted in red and yellow, respectively. Data points from the radar sensors are located behind the wall. (d) An autonomous mobile robot with two lidar sensors for tunnel surveillance. The two lidar sensors employed (VLP-16 and RPLIDAR-A2) are illustrated in yellow. 42 IEEE ROBOTICS & AUTOMATION MAGAZINE SEPTEMBER 2023