Relative Position Estimation in Multi-Agent Systems Using Attitude-Coupled Range Measurements

TL;DR

This paper proposes a simple framework for 3D relative position estimation in multi-agent systems using only range measurements and inertial sensors, achieving 40-50 cm accuracy in experiments.

Contribution

It introduces a sufficient observability condition and a practical framework that enables accurate relative positioning without GPS in multi-agent systems.

Findings

Achieves 40-50 cm positioning accuracy in experiments.

Validates the framework through simulation and real-world tests.

Provides a sufficient condition for observability in range-based relative positioning.

Abstract

The ability to accurately estimate the position of robotic agents relative to one another, in possibly GPS-denied environments, is crucial to execute collaborative tasks. Inter-agent range measurements are available at a low cost, due to technologies such as ultra-wideband radio. However, the task of three-dimensional relative position estimation using range measurements in multi-agent systems suffers from unobservabilities. This letter presents a sufficient condition for the observability of the relative positions, and satisfies the condition using a simple framework with only range measurements, an accelerometer, a rate gyro, and a magnetometer. The framework has been tested in simulation and in experiments, where 40-50 cm positioning accuracy is achieved using inexpensive off-the-shelf hardware.