Autonomous Flights inside Narrow Tunnels

TL;DR

This paper presents an autonomous aerial system capable of navigating narrow tunnels as small as 0.5 meters in diameter, combining real-time perception and novel motion planning to outperform human pilots in challenging environments.

Contribution

The paper introduces a new autonomous navigation system for narrow tunnels, integrating a virtual omni-directional perception module and a motion planner that accounts for perception and airflow disturbances.

Findings

System successfully navigates tunnels narrower than 0.5 m

Outperforms human pilots in tunnel navigation tasks

Open-source deployment pipeline provided for future use

Abstract

Multirotors are usually desired to enter confined narrow tunnels that are barely accessible to humans in various applications including inspection, search and rescue, and so on. This task is extremely challenging since the lack of geometric features and illuminations, together with the limited field of view, cause problems in perception; the restricted space and significant ego airflow disturbances induce control issues. This paper introduces an autonomous aerial system designed for navigation through tunnels as narrow as 0.5 m in diameter. The real-time and online system includes a virtual omni-directional perception module tailored for the mission and a novel motion planner that incorporates perception and ego airflow disturbance factors modeled using camera projections and computational fluid dynamics analyses, respectively. Extensive flight experiments on a custom-designed quadrotor are conducted in multiple realistic narrow tunnels to validate the superior performance of the system, even over human pilots, proving its potential for real applications. Additionally, a deployment pipeline on other multirotor platforms is outlined and open-source packages are provided for future developments.