Title
Recovery RL: Safe Reinforcement Learning With Learned Recovery Zones
Abstract
Safety remains a central obstacle preventing widespread use of RL in the real world: learning new tasks in uncertain environments requires extensive exploration, but safety requires limiting exploration. We propose Recovery RL, an algorithm which navigates this tradeoff by (1) leveraging offline data to learn about constraint violating zones <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">before</i> policy learning and (2) <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">separating</i> the goals of improving task performance and constraint satisfaction across two policies: a task policy that only optimizes the task reward and a recovery policy that guides the agent to safety when constraint violation is likely. We evaluate Recovery RL on 6 simulation domains, including two contact-rich manipulation tasks and an image-based navigation task, and an image-based obstacle avoidance task on a physical robot. We compare Recovery RL to 5 prior safe RL methods which jointly optimize for task performance and safety via constrained optimization or reward shaping and find that Recovery RL outperforms the next best prior method across all domains. Results suggest that Recovery RL trades off constraint violations and task successes 2–20 times more efficiently in simulation domains and 3 times more efficiently in physical experiments. See <uri xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">https://tinyurl.com/rl-recovery</uri> for videos and supplementary material.
Year
DOI
Venue
2021
10.1109/LRA.2021.3070252
IEEE Robotics and Automation Letters
Keywords
DocType
Volume
Reinforcement learning,safety
Journal
6
Issue
ISSN
Citations 
3
2377-3766
1
PageRank 
References 
Authors
0.34
0
10
Name
Order
Citations
PageRank
Brijen Thananjeyan1133.93
Ashwin Balakrishna246.80
Suraj Nair324.41
Michael Luo411.02
Krishnan Srinivasan510.34
Minho Hwang674.18
Joseph E. Gonzalez72219102.68
Julian Ibarz821728.98
Chelsea Finn981957.17
Ken Goldberg103785369.80