Tightly Coupled Model for Indoor Positioning based on UWB/INS

In this paper a tightly coupled indoor positioning system combining Ultra-Wideband (UWB) measurements with low-cost MEMS inertial navigation system (INS) measurements is proposed. Wireless sensor signal outage and severe multipath propagation very often lead to ranging errors, which make pure UWB-based localization less effective. Moreover, inertial sensors have their drift with time. A tightly coupled system is uesd to estimate moving target position and attitude in the indoor conditions. In order to eliminate the clock error, Time Difference of Arrival (TDOA) approach is used. Dynamic and static tests are carried on for the tightly coupled approach. Experimental results show that the tightly coupled indoor positioning system can improve the single system position accuracy and achieve the position and attitude real-time tracking of moving targets.