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 before policy learning and (2)
separating 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 https://tinyurl.com/rl-recovery for videos and supplementary
material.
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Recovery RL: Safe Reinforcement Learning with Learned Recovery Zones
attributed to: Brijen Thananjeyan, Ashwin Balakrishna, Suraj Nair, Michael Luo, Krishnan Srinivasan, Minho Hwang, Joseph E. Gonzalez, Julian Ibarz, Chelsea Finn, Ken Goldberg
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 before policy learning and (2)
separating 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.
0
Vulnerabilities & Strengths