SLAM Robotics 3 Degrees of freedom (mechanics) 2 Front end 2 IMU 2 Iterative methods 2 Kalman filters 2 LiDAR 2 Optical radar 2 Perceptually degraded scene 2 Performance 2 Simultaneous localization and mapping 2 Simultaneous localization and mapping algorithms 2 Six degrees of freedom 2 State estimation 2 Tightly-coupled 2 Underground tunnels 2 perceptually degraded scenes 2 state estimation 2 3D reconstruction 1 Background modelling 1 Cognitive mapping 1 Computer vision 1 Depth data integration 1 Egomotion estimation 1 Image change detection 1 Image features 1 Loop closure 1 Loop closure detection 1 Maintenance 1