LIDAR Simultaneous Localization and Mapping

Simultaneous Localization and Mapping (SLAM) is a core capability required for a robot to explore and understand its environment. We have developed a large scale SLAM system capable of building maps of industrial and urban facilities using LIDAR.

Online LiDAR-SLAM for Legged Robots with Deep-Learned Loop Closure (ICRA 2020)

In this paper, we present a factor-graph LiDAR SLAM system which incorporates a state-of-the-art deeply learned feature-based loop closure detector to enable a legged robot to localize and map in industrial environments. These facilities can be badly lit and comprised of indistinct metallic structures, thus our system uses only LiDAR sensing and was developed to run on the quadruped robot’s navigation PC. Point clouds are accumulated using an inertial-kinematic state estimator before being aligned using ICP registration. To close loops we use a loop proposal mechanism which matches individual segments between clouds. We trained a descriptor offline to match these segments. The efficiency of our method comes from carefully designing the network architecture to minimize the number of parameters such that this deep learning method can be deployed in real-time using only the CPU of a legged robot, a major contribution of this work. The set of odometry and loop closure factors are updated using pose graph optimization. Finally we present an efficient risk alignment prediction method which verifies the reliability of the registrations. Experimental results at an industrial facility demonstrated the robustness and flexibility of our system, including autonomous following paths derived from the SLAM map.