Mobile robot 6D pose estimation using a wireless localization network

Global navigation satellite systems (GNSS) are widely used for localization on Earth, but are not available on other planets, so that robotic planetary exploration missions need to use alternative methods for localization. This paper presents a wireless localization network (WLN) for estimating the 3D position and 3D orientation of a mobile robot. It consists of at least one reference 24 GHz radar node with known pose, and a mobile node on the robot. The reference nodes can determine the distance and both spatial angles to the mobile robot (thus locating it in 3D) using round-trip time of flight measurements and digital beamforming. We use an extended Kalman filter (EKF) to fuse these results with the readings from the mobile node, and an inclinometer to determine the complete 6D pose of the mobile robot. Measurements in a realistic scenario prove the feasibility of the proposed concept.