Safety Modulation: Enhancing Safety in Reinforcement Learning through Cost-Modulated Rewards

Fuente: arXiv
Salvato in:
Dettagli Bibliografici
Autori principali: Zhang, Hanping, Guo, Yuhong
Natura: Preprint
Pubblicazione: 2025
Soggetti:
Accesso online:
Tags: Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
_version_ 1866917976265981952
author Zhang, Hanping
Guo, Yuhong
author_facet Zhang, Hanping
Guo, Yuhong
contents Safe Reinforcement Learning (Safe RL) aims to train an RL agent to maximize its performance in real-world environments while adhering to safety constraints, as exceeding safety violation limits can result in severe consequences. In this paper, we propose a novel safe RL approach called Safety Modulated Policy Optimization (SMPO), which enables safe policy function learning within the standard policy optimization framework through safety modulated rewards. In particular, we consider safety violation costs as feedback from the RL environments that are parallel to the standard awards, and introduce a Q-cost function as safety critic to estimate expected future cumulative costs. Then we propose to modulate the rewards using a cost-aware weighting function, which is carefully designed to ensure the safety limits based on the estimation of the safety critic, while maximizing the expected rewards. The policy function and the safety critic are simultaneously learned through gradient descent during online interactions with the environment. We conduct experiments using multiple RL environments and the experimental results demonstrate that our method outperforms several classic and state-of-the-art comparison methods in terms of overall safe RL performance.
format Preprint
id arxiv_https___arxiv_org_abs_2504_03040
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Safety Modulation: Enhancing Safety in Reinforcement Learning through Cost-Modulated Rewards
Zhang, Hanping
Guo, Yuhong
Machine Learning
Artificial Intelligence
Safe Reinforcement Learning (Safe RL) aims to train an RL agent to maximize its performance in real-world environments while adhering to safety constraints, as exceeding safety violation limits can result in severe consequences. In this paper, we propose a novel safe RL approach called Safety Modulated Policy Optimization (SMPO), which enables safe policy function learning within the standard policy optimization framework through safety modulated rewards. In particular, we consider safety violation costs as feedback from the RL environments that are parallel to the standard awards, and introduce a Q-cost function as safety critic to estimate expected future cumulative costs. Then we propose to modulate the rewards using a cost-aware weighting function, which is carefully designed to ensure the safety limits based on the estimation of the safety critic, while maximizing the expected rewards. The policy function and the safety critic are simultaneously learned through gradient descent during online interactions with the environment. We conduct experiments using multiple RL environments and the experimental results demonstrate that our method outperforms several classic and state-of-the-art comparison methods in terms of overall safe RL performance.
title Safety Modulation: Enhancing Safety in Reinforcement Learning through Cost-Modulated Rewards
topic Machine Learning
Artificial Intelligence
url https://arxiv.org/abs/2504.03040