Direct Preference Optimization for Primitive-Enabled Hierarchical RL: A Bilevel Approach

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Singh, Utsav, Chakraborty, Souradip, Suttle, Wesley A., Sadler, Brian M., Asher, Derrik E., Sahu, Anit Kumar, Shah, Mubarak, Namboodiri, Vinay P., Bedi, Amrit Singh
Format: Preprint
Published: 2024
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866918449002840064
author Singh, Utsav
Chakraborty, Souradip
Suttle, Wesley A.
Sadler, Brian M.
Asher, Derrik E.
Sahu, Anit Kumar
Shah, Mubarak
Namboodiri, Vinay P.
Bedi, Amrit Singh
author_facet Singh, Utsav
Chakraborty, Souradip
Suttle, Wesley A.
Sadler, Brian M.
Asher, Derrik E.
Sahu, Anit Kumar
Shah, Mubarak
Namboodiri, Vinay P.
Bedi, Amrit Singh
contents Hierarchical reinforcement learning (HRL) enables agents to solve complex, long-horizon tasks by decomposing them into manageable sub-tasks. However, HRL methods face two fundamental challenges: (i) non-stationarity caused by the evolving lower-level policy during training, which destabilizes higher-level learning, and (ii) the generation of infeasible subgoals that lower-level policies cannot achieve. To address these challenges, we introduce DIPPER, a novel HRL framework that formulates goal-conditioned HRL as a bi-level optimization problem and leverages direct preference optimization (DPO) to train the higher-level policy. By learning from stationary preference comparisons over subgoal sequences rather than rewards that depend on the evolving lower-level policy, DIPPER mitigates the impact of non-stationarity on hierarchical learning. To address infeasible subgoals, DIPPER incorporates lower-level value function regularization that encourages the higher-level policy to propose achievable subgoals. We also introduce two novel metrics to quantitatively verify that DIPPER mitigates non-stationarity and infeasible subgoal generation issues in HRL. We perform empirical evaluations on challenging robotic navigation and manipulation benchmarks and show that DIPPER achieves upto 40% improvements over state-of-the-art baselines, demonstrating that preference-based methods can effectively alleviate persistent challenges in hierarchical
format Preprint
id arxiv_https___arxiv_org_abs_2411_00361
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Direct Preference Optimization for Primitive-Enabled Hierarchical RL: A Bilevel Approach
Singh, Utsav
Chakraborty, Souradip
Suttle, Wesley A.
Sadler, Brian M.
Asher, Derrik E.
Sahu, Anit Kumar
Shah, Mubarak
Namboodiri, Vinay P.
Bedi, Amrit Singh
Machine Learning
Hierarchical reinforcement learning (HRL) enables agents to solve complex, long-horizon tasks by decomposing them into manageable sub-tasks. However, HRL methods face two fundamental challenges: (i) non-stationarity caused by the evolving lower-level policy during training, which destabilizes higher-level learning, and (ii) the generation of infeasible subgoals that lower-level policies cannot achieve. To address these challenges, we introduce DIPPER, a novel HRL framework that formulates goal-conditioned HRL as a bi-level optimization problem and leverages direct preference optimization (DPO) to train the higher-level policy. By learning from stationary preference comparisons over subgoal sequences rather than rewards that depend on the evolving lower-level policy, DIPPER mitigates the impact of non-stationarity on hierarchical learning. To address infeasible subgoals, DIPPER incorporates lower-level value function regularization that encourages the higher-level policy to propose achievable subgoals. We also introduce two novel metrics to quantitatively verify that DIPPER mitigates non-stationarity and infeasible subgoal generation issues in HRL. We perform empirical evaluations on challenging robotic navigation and manipulation benchmarks and show that DIPPER achieves upto 40% improvements over state-of-the-art baselines, demonstrating that preference-based methods can effectively alleviate persistent challenges in hierarchical
title Direct Preference Optimization for Primitive-Enabled Hierarchical RL: A Bilevel Approach
topic Machine Learning
url https://arxiv.org/abs/2411.00361