Unmanned aerial vehicles offer a safe and fast approach to the production of three-dimensional spatial data on the surrounding space. In this article, we present a low-cost SLAM-based drone for creating indoor exploration maps of building interiors. The focus is on emergency response mapping in inaccessible or potentially dangerous places. For this purpose, we used a quadcopter microdrone equipped with laser range finders (1D scanners) and an optical sensor for mapping and positioning. The employed SLAM is designed to map indoor spaces with planar structures through graph op-timization. It performs loop-closure detection and correction to recognize previously visited places and correct the accumulated drift over time. The proposed methodology was validated for several indoor environments. We investigated the performance of our drone against a multi-layer LI-DAR-carrying macrodrone, a vision-aided navigation helmet, and ground truth obtained with a terrestrial laser scanner. The experimental results indicated that our SLAM system is capable of creating quality exploration maps of small indoor spaces, and handling of the loop-closure problem. The accumulated drift without loop closure was on average 1.1% (0.35 m) over a 31 m long ac-quisition trajectory. Moreover, the comparison results demonstrated that our flying microdrone provided a comparable performance to the multi-layer LIDAR-based macrodrone given the low deviation between the point clouds built by both drones. About 85 % of the cloud-to-cloud distances were less than 10 cm.

Date Submitted: 2023-11-21