🤖 AI Summary
This work addresses the instability of policies in offline reinforcement learning caused by insufficient data coverage and distributional shift. The authors propose a residual-based offline reinforcement learning framework that explicitly models dynamic estimation error to construct an empirical residual, which is then used to define a contractive residual Bellman operator. This operator is theoretically guaranteed to possess an asymptotically optimal fixed point and finite-sample convergence. By integrating empirical residual estimation, a reformulated Bellman equation, and deep Q-networks, the framework enables stable policy learning without any environment interaction. Experimental results on a stochastic CartPole environment demonstrate that the proposed residual offline DQN algorithm significantly outperforms existing methods.
📝 Abstract
Offline reinforcement learning (RL) has received increasing attention for learning policies from previously collected data without interaction with the real environment, which is particularly important in high-stakes applications. While a growing body of work has developed offline RL algorithms, these methods often rely on restrictive assumptions about data coverage and suffer from distribution shift. In this paper, we propose a residuals-based offline RL framework for general state and action spaces. Specifically, we define a residuals-based Bellman optimality operator that explicitly incorporates estimation error in learning transition dynamics into policy optimization by leveraging empirical residuals. We show that this Bellman operator is a contraction mapping and identify conditions under which its fixed point is asymptotically optimal and possesses finite-sample guarantees. We further develop a residuals-based offline deep Q-learning (DQN) algorithm. Using a stochastic CartPole environment, we demonstrate the effectiveness of our residuals-based offline DQN algorithm.