  We introduce LIDAUS Localization of IoT Device via Anchor UAV SLAM), an
infrastructure-free, multi-stage SLAM system that utilizes an Unmanned Aerial
Vehicle (UAV) to accurately localize IoT devices in a 3D indoor space where GPS
signals are unavailable or weak, e.g., manufacturing factories, disaster sites,
or smart buildings. The lack of GPS signals and infrastructure support makes
most of the existing indoor localization systems not practical when localizing
a large number of wireless IoT devices. In addition, safety concerns, access
restriction, and simply the huge amount of IoT devices make it not practical
for humans to manually localize and track IoT devices. To address these
challenges, the UAV in our LIDAUS system conducts multi-stage 3D SLAM trips to
localize devices based only on RSSIs, the most widely available measurement of
the signals of almost all commodity IoT devices. The main novelties of the
system include a weighted entropy-based clustering algorithm to select high
quality RSSI observation locations, a 3D U-SLAM algorithm that is enhanced by
deploying anchor beacons along the UAV's path, and the path planning based on
Eulerian cycles on multi-layer grid graphs that model the space in exploring
stage and Steiner tree paths in searching stages. Our simulations and
experiments of Bluetooth IoT devices have demonstrated that the system can
achieve high localization accuracy based only on RSSIs of commodity IoT
devices.
