Criticality and Safety Margins for Reinforcement Learning

Fuente: arXiv
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Main Authors: Grushin, Alexander, Woods, Walt, Velasquez, Alvaro, Khan, Simon
Format: Preprint
Published: 2024
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_version_ 1866910970867089408
author Grushin, Alexander
Woods, Walt
Velasquez, Alvaro
Khan, Simon
author_facet Grushin, Alexander
Woods, Walt
Velasquez, Alvaro
Khan, Simon
contents State of the art reinforcement learning methods sometimes encounter unsafe situations. Identifying when these situations occur is of interest both for post-hoc analysis and during deployment, where it might be advantageous to call out to a human overseer for help. Efforts to gauge the criticality of different points in time have been developed, but their accuracy is not well established due to a lack of ground truth, and they are not designed to be easily interpretable by end users. Therefore, we seek to define a criticality framework with both a quantifiable ground truth and a clear significance to users. We introduce true criticality as the expected drop in reward when an agent deviates from its policy for n consecutive random actions. We also introduce the concept of proxy criticality, a low-overhead metric that has a statistically monotonic relationship to true criticality. Safety margins make these interpretable, when defined as the number of random actions for which performance loss will not exceed some tolerance with high confidence. We demonstrate this approach in several environment-agent combinations; for an A3C agent in an Atari Beamrider environment, the lowest 5% of safety margins contain 47% of agent losses; i.e., supervising only 5% of decisions could potentially prevent roughly half of an agent's errors. This criticality framework measures the potential impacts of bad decisions, even before those decisions are made, allowing for more effective debugging and oversight of autonomous agents.
format Preprint
id arxiv_https___arxiv_org_abs_2409_18289
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Criticality and Safety Margins for Reinforcement Learning
Grushin, Alexander
Woods, Walt
Velasquez, Alvaro
Khan, Simon
Machine Learning
Artificial Intelligence
Systems and Control
68T07
I.2.6
State of the art reinforcement learning methods sometimes encounter unsafe situations. Identifying when these situations occur is of interest both for post-hoc analysis and during deployment, where it might be advantageous to call out to a human overseer for help. Efforts to gauge the criticality of different points in time have been developed, but their accuracy is not well established due to a lack of ground truth, and they are not designed to be easily interpretable by end users. Therefore, we seek to define a criticality framework with both a quantifiable ground truth and a clear significance to users. We introduce true criticality as the expected drop in reward when an agent deviates from its policy for n consecutive random actions. We also introduce the concept of proxy criticality, a low-overhead metric that has a statistically monotonic relationship to true criticality. Safety margins make these interpretable, when defined as the number of random actions for which performance loss will not exceed some tolerance with high confidence. We demonstrate this approach in several environment-agent combinations; for an A3C agent in an Atari Beamrider environment, the lowest 5% of safety margins contain 47% of agent losses; i.e., supervising only 5% of decisions could potentially prevent roughly half of an agent's errors. This criticality framework measures the potential impacts of bad decisions, even before those decisions are made, allowing for more effective debugging and oversight of autonomous agents.
title Criticality and Safety Margins for Reinforcement Learning
topic Machine Learning
Artificial Intelligence
Systems and Control
68T07
I.2.6
url https://arxiv.org/abs/2409.18289