An Indoor Backpack System for 2-D and 3-D Mapping of Building Interiors

This letter presents a backpack mapping system for creating indoor 2-D and 3-D maps of building interiors. For many applications, indoor mobile mapping provides a 3-D structure via an indoor map. Because there are significant roll and pitch motions of the indoor mobile mapping system, the need arises for a moving mobile system with 6 degrees of freedom (DOFs) (x, y, and z positions and roll, yaw, and pitch angles). First, we present a 6-DOF pose estimation algorithm by fusing 2-D laser scanner data with inertial sensor data using an extended Kalman filter-based method. The estimated 6-DOF pose is used as the initialized transformation for consecutive map alignment in 3-D map building. The 6-DOF pose gives a full 3-D estimation of the system pose and is used to accelerate the map alignment process and also align the two maps directly when there are few or no overlapping areas between the maps. Our results show that the proposed system effectively builds a consistent 2-D grid map and a 3-D point cloud map of an indoor environment.