  The following paper presents an adaptive anchor pairs selection method for
ultra-wideband (UWB) Time Difference of Arrival (TDOA) based positioning
systems. The method divides the area covered by the system into several zones
and assigns them anchor pair sets. The pair sets are determined during
calibration based on localization root mean square error (RMSE). The
calibration assumes driving a mobile platform equipped with a LiDAR sensor and
a UWB tag through the specified zones. The robot is localized separately based
on a large set of different TDOA pairs and using a LiDAR, which acts as the
reference. For each zone, the TDOA pairs set for which the registered RMSE is
lowest is selected and used for localization in the routine system work. The
proposed method has been tested with simulations and experiments. The results
for both simulated static and experimental dynamic scenarios have proven that
the adaptive selection of the anchor nodes leads to an increase in localization
accuracy. In the experiment, the median trajectory error for a moving person
localization was at a level of 25 cm.
