Probabilistic Subgoal Representations for Hierarchical Reinforcement learning

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A4 Artikkeli konferenssijulkaisussa

Date

2024

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en

Pages

16

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Proceedings of Machine Learning Research, Volume 235, pp. 51755-51770

Abstract

In goal-conditioned hierarchical reinforcement learning (HRL), a high-level policy specifies a subgoal for the low-level policy to reach. Effective HRL hinges on a suitable subgoal representation function, abstracting state space into latent subgoal space and inducing varied low-level behaviors. Existing methods adopt a subgoal representation that provides a deterministic mapping from state space to latent subgoal space. Instead, this paper utilizes Gaussian Processes (GPs) for the first probabilistic subgoal representation. Our method employs a GP prior on the latent subgoal space to learn a posterior distribution over the subgoal representation functions while exploiting the long-range correlation in the state space through learnable kernels. This enables an adaptive memory that integrates long-range subgoal information from prior planning steps allowing to cope with stochastic uncertainties. Furthermore, we propose a novel learning objective to facilitate the simultaneous learning of probabilistic subgoal representations and policies within a unified framework. In experiments, our approach outperforms state-of-the-art baselines in standard benchmarks but also in environments with stochastic elements and under diverse reward conditions. Additionally, our model shows promising capabilities in transferring low-level policies across different tasks.

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Publisher Copyright: Copyright 2024 by the author(s)

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Citation

Wang, V H, Wang, T, Yang, W, Kämäräinen, J K & Pajarinen, J 2024, ' Probabilistic Subgoal Representations for Hierarchical Reinforcement learning ', Proceedings of Machine Learning Research, vol. 235, pp. 51755-51770 . < https://proceedings.mlr.press/v235/wang24bx.html >