UAVs Beneath the Surface: Cooperative Autonomy for Subterranean Search and Rescue in DARPA SubT

Matěj Petrlı́k, Pavel Petráček, Vı́t Krátký, Tomáš Musil, Yurii Stasinchuk, Matouš Vrba,
Tomáš Báča, Daniel Heřt, Martin Pecka, Tomáš Svoboda, Martin Saska

Published in Field Robotics, 2023    |    Paper available: pdf

 

Abstract

This paper presents a novel approach for autonomous cooperating UAVs in search and rescue operations in subterranean domains with complex topology. The proposed system was ranked second in the Virtual Track of the DARPA SubT Finals as part of the team CTU-CRAS-NORLAB. In contrast to the winning solution that was developed specifically for the Virtual Track, the proposed solution also proved to be a robust system for deployment onboard physical UAVs flying in the extremely harsh and confined environment of the real-world competition. The proposed approach enables fully autonomous and decentralized deployment of a UAV team with seamless simulation-to-world transfer, and proves its advantage over less mobile UGV teams in the flyable space of diverse environments. The main contributions of the paper are present in the mapping and navigation pipelines. The mapping approach employs novel map representations --- SphereMap for efficient risk-aware long-distance planning, FacetMap for surface coverage, and the compressed topological-volumetric LTVMap for allowing multi-robot cooperation under low-bandwidth communication. These representations are used in navigation together with novel methods for visibility-constrained informed search in a general 3D environment with no assumptions about the environment structure, while balancing deep exploration with sensor-coverage exploitation. The proposed solution also includes a visual-perception pipeline for on-board detection and localization of objects of interest in four RGB stream at 5 Hz each without a dedicated GPU. Apart from participation in the DARPA SubT, the performance of the UAV system is supported by extensive experimental verification in diverse environments with both qualitative and quantitative evaluation.

 

Open-source 

All our open-source software including the whole control and simulation stacks is available at github.com/ctu-mrs.

 

Datasets

 

Cite as 

@article{petrlik2023uavs,
  author = {Petrlik, Matej and Petracek, Pavel and Kratky, Vit and Musil, Tomas and Stasinchuk, Yurii and Vrba, Matous and Baca, Tomas and Hert, Daniel and Pecka, Martin and Svoboda, Tomas and Saska, Martin},
  journal = {Field Robotics},
  title = {{UAVs Beneath the Surface: Cooperative Autonomy for Subterranean Search and Rescue in DARPA SubT}},
  year = {2023},
  volume={3},
  pages={1--68},
  doi={https://doi.org/10.55417/fr.2023001},
  month={January},
  pdf="https://fieldrobotics.net/Field_Robotics/Volume_3_files/Vol3_01.pdf",
}
 

Video material

Prize round - UAV Red onboard data

 

Prize round - UAV Red external camera

 

Prize round - UAV Green onboard data

 

Prize round - UAV Green external camera

 

Prize round - UAV Blue onboard data

 

Prize round - UAV Blue external camera

 

DARPA SubT Challenge Post-event Testing: UAV Green - Tunnel and Cave Environment - GoPro

 

DARPA SubT Challenge Post-event Testing: UAV Green - Tunnel and Cave Environment - Onboard Data

 

DARPA SubT Challenge Post-event Testing: UAV Blue - Tunnel Environment 2 - GoPro

 

DARPA SubT Challenge Post-event Testing: UAV Blue - Tunnel Environment 2 - Onboard Data

 

DARPA SubT Challenge Post-event Testing: UAV Blue - Urban Environment - GoPro

 

DARPA SubT Challenge Post-event Testing: UAV Blue - Urban Environment - Onboard Data

 

DARPA SubT Challenge Post-event Testing: UAV Yellow - Urban Environment - GoPro

 

DARPA SubT Challenge Post-event Testing: UAV Yellow - Urban Environment - Onboard Data

 

DARPA SubT Challenge Post-event Testing: UAV Yellow - Urban Environment (Hall and Metro) - GoPro

 

DARPA SubT Challenge Post-event Testing: UAV Yellow - Urban Environment (Hall and Metro) - Onboard Data

 

DARPA SubT Challenge Post-event Testing: UAV Pink - Urban Environment (Storeroom) - GoPro

DARPA SubT Challenge Post-event Testing: UAV Pink - Urban Environment (Storeroom) - Onboard Data