Decimeter-Accuracy Positioning for Drones Using Two-Stage Trilateration in a GPS-Denied Environment
Yu-Er Chen, Huan-Huan Liew, Ju-Chin Chao, Ruey‐Beei Wu
Abstract
This study proposes a high-accuracy two-stage trilateration method that enables real-time positioning in global position system (GPS)-denied areas, such as unmanned aerial vehicles (UAVs) under bridges and targets in vegetation or indoors, where automated drone operation is difficult, and there are few localization methods. This method uses ultrawideband (UWB) with high-ranging accuracy and a high transmission rate as the positioning sensor. The drone and the target are equipped with multiple UWBs, and the relative distance is calculated through the signal transmission between the UWB devices so as to determine the position of the target in a fixed coordinate system. In practice, this method uses the UWB anchors on the ground to locate the UAV moving in the air, and the altitude error can be reduced from 8–10 m to less than 1 m. The moving UAV can also be used as the anchor to locate fixed objects on the ground in areas with poor GPS, and the relative position error is reduced from 2.02 to 0.35 m, and the relative altitude error is reduced from 3.39 to 0.32 m. This study alleviates the insufficient accuracy of the trilateration method when the UWB anchors are in the coplanar space, so as to improve the reliability of the positioning and navigation of the UAV in the GPS-denied area.