Robust Target-relative Localization with Ultra-Wideband Ranging and Communication

TL;DR

This paper presents a robust method for quadcopters to localize and track a target using UWB sensors and communication, integrating sensor fusion and target orientation transfer for autonomous relative positioning.

Contribution

It introduces a novel EKF-based estimator combining UWB, onboard sensors, and target orientation communication for improved relative localization.

Findings

Successful autonomous relative positioning with static targets.

Effective tracking of moving targets.

Robust localization despite target speed uncertainties.

Abstract

In this paper we propose a method to achieve relative positioning and tracking of a target by a quadcopter using Ultra-wideband (UWB) ranging sensors, which are strategically installed to help retrieve both relative position and bearing between the quadcopter and target. To achieve robust localization for autonomous flight even with uncertainty in the speed of the target, two main features are developed. First, an estimator based on Extended Kalman Filter (EKF) is developed to fuse UWB ranging measurements with data from onboard sensors including inertial measurement unit (IMU), altimeters and optical flow. Second, to properly handle the coupling of the target's orientation with the range measurements, UWB based communication capability is utilized to transfer the target's orientation to the quadcopter. Experiment results demonstrate the ability of the quadcopter to control its position relative to the target autonomously in both cases when the target is static and moving.