This article presents the CERBERUS robotic system-of-systems, which won the DARPA
Subterranean Challenge Final Event in 2021. The Subterranean Challenge was organized by DARPA
with the vision to facilitate the novel technologies necessary to reliably explore diverse underground
environments despite the grueling challenges they present for robotic autonomy. Due to their
geometric complexity, degraded perceptual conditions combined with lack of GNSS support, austere
navigation conditions, and denied communications, subterranean settings render autonomous operations particularly demanding. In response to this challenge, we developed the CERBERUS system
which exploits the synergy of legged and flying robots, coupled with robust control especially for
overcoming perilous terrain, multi-modal and multi-robot perception for localization and mapping in
conditions of sensor degradation, and resilient autonomy through unified exploration path planning
and local motion planning that reflects robot-specific limitations. Based on its ability to explore
diverse underground environments and its high-level command and control by a single human supervisor, CERBERUS demonstrated efficient exploration, reliable detection of objects of interest,
and accurate mapping. In this article, we report results from both the preliminary runs and the final
Prize Round of the DARPA Subterranean Challenge, and discuss highlights and challenges faced,
alongside lessons learned for the benefit of the community.
