Decentralized and Fully Onboard: Range-Aided Cooperative Localization and Navigation on Micro Aerial Vehicles

TL;DR

This paper introduces a decentralized, range-aided localization and formation control method for micro aerial vehicles, enabling accurate navigation without centralized computation or external localization systems, demonstrated through real-world experiments.

Contribution

It proposes a novel decentralized approach combining block coordinate descent for localization and factor graph inference for formation control, improving scalability and robustness.

Findings

Achieves decimeter-level positioning accuracy.

Operates without strict coordination or external systems.

Successfully demonstrated in indoor and outdoor experiments.

Abstract

Controlling a team of robots in a coordinated manner is challenging because centralized approaches (where all computation is performed on a central machine) scale poorly, and globally referenced external localization systems may not always be available. In this work, we consider the problem of range-aided decentralized localization and formation control. In such a setting, each robot estimates its relative pose by combining data only from onboard odometry sensors and distance measurements to other robots in the team. Additionally, each robot calculates the control inputs necessary to collaboratively navigate an environment to accomplish a specific task, for example, moving in a desired formation while monitoring an area. We present a block coordinate descent approach to localization that does not require strict coordination between the robots. We present a novel formulation for formation control as inference on factor graphs that takes into account the state estimation uncertainty and can be solved efficiently. Our approach to range-aided localization and formation-based navigation is completely decentralized, does not require specialized trajectories to maintain formation, and achieves decimeter-level positioning and formation control accuracy. We demonstrate our approach through multiple real experiments involving formation flights in diverse indoor and outdoor environments.