Skip to main content

Lund University Publications

LUND UNIVERSITY LIBRARIES

Time-efficient reinforcement learning with stochastic stateful policies

Al-Hafez, Firas ; Zhao, Guoping ; Peters, Jan and Tateo, Davide LU orcid (2024) 12th International Conference on Learning Representations, ICLR 2024
Abstract

Stateful policies play an important role in reinforcement learning, such as handling partially observable environments, enhancing robustness, or imposing an inductive bias directly into the policy structure. The conventional method for training stateful policies is Backpropagation Through Time (BPTT), which comes with significant drawbacks, such as slow training due to sequential gradient propagation and the occurrence of vanishing or exploding gradients. The gradient is often truncated to address these issues, resulting in a biased policy update. We present a novel approach for training stateful policies by decomposing the latter into a stochastic internal state kernel and a stateless policy, jointly optimized by following the stateful... (More)

Stateful policies play an important role in reinforcement learning, such as handling partially observable environments, enhancing robustness, or imposing an inductive bias directly into the policy structure. The conventional method for training stateful policies is Backpropagation Through Time (BPTT), which comes with significant drawbacks, such as slow training due to sequential gradient propagation and the occurrence of vanishing or exploding gradients. The gradient is often truncated to address these issues, resulting in a biased policy update. We present a novel approach for training stateful policies by decomposing the latter into a stochastic internal state kernel and a stateless policy, jointly optimized by following the stateful policy gradient. We introduce different versions of the stateful policy gradient theorem, enabling us to easily instantiate stateful variants of popular reinforcement learning and imitation learning algorithms. Furthermore, we provide a theoretical analysis of our new gradient estimator and compare it with BPTT. We evaluate our approach on complex continuous control tasks, e.g. humanoid locomotion, and demonstrate that our gradient estimator scales effectively with task complexity while offering a faster and simpler alternative to BPTT.

(Less)
Please use this url to cite or link to this publication:
author
; ; and
publishing date
type
Contribution to conference
publication status
published
subject
conference name
12th International Conference on Learning Representations, ICLR 2024
conference location
Hybrid, Vienna, Austria
conference dates
2024-05-07 - 2024-05-11
external identifiers
  • scopus:85200568592
language
English
LU publication?
no
additional info
Publisher Copyright: © 2024 12th International Conference on Learning Representations, ICLR 2024. All rights reserved.
id
08f2f52b-bbf6-4185-9bbf-76116268de92
date added to LUP
2025-10-16 14:06:36
date last changed
2025-10-17 12:07:50
@misc{08f2f52b-bbf6-4185-9bbf-76116268de92,
  abstract     = {{<p>Stateful policies play an important role in reinforcement learning, such as handling partially observable environments, enhancing robustness, or imposing an inductive bias directly into the policy structure. The conventional method for training stateful policies is Backpropagation Through Time (BPTT), which comes with significant drawbacks, such as slow training due to sequential gradient propagation and the occurrence of vanishing or exploding gradients. The gradient is often truncated to address these issues, resulting in a biased policy update. We present a novel approach for training stateful policies by decomposing the latter into a stochastic internal state kernel and a stateless policy, jointly optimized by following the stateful policy gradient. We introduce different versions of the stateful policy gradient theorem, enabling us to easily instantiate stateful variants of popular reinforcement learning and imitation learning algorithms. Furthermore, we provide a theoretical analysis of our new gradient estimator and compare it with BPTT. We evaluate our approach on complex continuous control tasks, e.g. humanoid locomotion, and demonstrate that our gradient estimator scales effectively with task complexity while offering a faster and simpler alternative to BPTT.</p>}},
  author       = {{Al-Hafez, Firas and Zhao, Guoping and Peters, Jan and Tateo, Davide}},
  language     = {{eng}},
  title        = {{Time-efficient reinforcement learning with stochastic stateful policies}},
  year         = {{2024}},
}