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Related papers: Trust Region-Guided Proximal Policy Optimization

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Proximal Policy Optimization (PPO) has been broadly applied to robotics learning, showcasing stable training performance. However, the fixed clipping bound setting may limit the performance of PPO. Specifically, there is no theoretical…

Machine Learning · Computer Science 2024-11-07 Ziqi Zhang , Jingzehua Xu , Zifeng Zhuang , Hongyin Zhang , Jinxin Liu , Donglin wang , Shuai Zhang

Trust region methods, such as TRPO, are often used to stabilize policy optimization algorithms in reinforcement learning (RL). While current trust region strategies are effective for continuous control, they typically require a…

Artificial Intelligence · Computer Science 2018-02-26 Ofir Nachum , Mohammad Norouzi , Kelvin Xu , Dale Schuurmans

Despite Proximal Policy Optimization (PPO) dominating policy gradient methods -- from robotic control to game AI -- its static trust region forces a brittle trade-off: aggressive clipping stifles early exploration, while late-stage updates…

Machine Learning · Computer Science 2025-05-26 Ben Rahman

We study reinforcement learning (RL) in the setting of continuous time and space, for an infinite horizon with a discounted objective and the underlying dynamics driven by a stochastic differential equation. Built upon recent advances in…

Machine Learning · Computer Science 2023-10-19 Hanyang Zhao , Wenpin Tang , David D. Yao

We introduce a constrained optimization method for policy gradient reinforcement learning, which uses a virtual trust region to regulate each policy update. In addition to using the proximity of one single old policy as the normal trust…

Machine Learning · Computer Science 2022-09-19 Hung Le , Thommen Karimpanal George , Majid Abdolshah , Dung Nguyen , Kien Do , Sunil Gupta , Svetha Venkatesh

Reinforcement learning (RL) has re-emerged as a natural approach for training interactive LLM agents in real-world environments. However, directly applying the widely used Group Relative Policy Optimization (GRPO) algorithm to multi-turn…

Machine Learning · Computer Science 2026-01-27 Junbo Li , Peng Zhou , Rui Meng , Meet P. Vadera , Lihong Li , Yang Li

Recently, Large Language Models (LLMs) have rapidly evolved, approaching Artificial General Intelligence (AGI) while benefiting from large-scale reinforcement learning to enhance Human Alignment (HA) and Reasoning. Recent reward-based…

Machine Learning · Computer Science 2025-06-19 Xuerui Su , Shufang Xie , Guoqing Liu , Yingce Xia , Renqian Luo , Peiran Jin , Zhiming Ma , Yue Wang , Zun Wang , Yuting Liu

Trust Region Policy Optimization (TRPO) is an iterative method that simultaneously maximizes a surrogate objective and enforces a trust region constraint over consecutive policies in each iteration. The combination of the surrogate…

Machine Learning · Computer Science 2023-02-17 Mingfei Sun , Benjamin Ellis , Anuj Mahajan , Sam Devlin , Katja Hofmann , Shimon Whiteson

Uncertainty estimation for Reinforcement Learning (RL) is a critical component in control tasks where agents must balance safe exploration and efficient learning. While deep neural networks have enabled breakthroughs in RL, they often lack…

Machine Learning · Computer Science 2025-12-22 Matthijs van der Lende , Juan Cardenas-Cartagena

Proximal policy optimization and trust region policy optimization (PPO and TRPO) with actor and critic parametrized by neural networks achieve significant empirical success in deep reinforcement learning. However, due to nonconvexity, the…

Machine Learning · Computer Science 2023-03-01 Boyi Liu , Qi Cai , Zhuoran Yang , Zhaoran Wang

Proximal Policy Optimization (PPO) is widely used in reinforcement learning due to its strong empirical performance, yet it lacks formal guarantees for policy improvement and convergence. PPO's clipped surrogate objective is motivated by a…

Machine Learning · Computer Science 2026-02-02 Razvan-Andrei Lascu , David Šiška , Łukasz Szpruch

On-policy deep reinforcement learning algorithms have low data utilization and require significant experience for policy improvement. This paper proposes a proximal policy optimization algorithm with prioritized trajectory replay (PTR-PPO)…

Machine Learning · Computer Science 2021-12-09 Xingxing Liang , Yang Ma , Yanghe Feng , Zhong Liu

Proximal Policy Optimization (PPO) is a highly popular policy-based deep reinforcement learning (DRL) approach. However, we observe that the homogeneous exploration process in PPO could cause an unexpected stability issue in the training…

Machine Learning · Computer Science 2022-12-14 Qisheng Zhang , Zhen Guo , Audun Jøsang , Lance M. Kaplan , Feng Chen , Dong H. Jeong , Jin-Hee Cho

Most methods in reinforcement learning use a Policy Gradient (PG) approach to learn a parametric stochastic policy that maps states to actions. The standard approach is to implement such a mapping via a neural network (NN) whose parameters…

Machine Learning · Computer Science 2024-05-29 Sergio Rozada , Antonio G. Marques

Offline reinforcement learning (RL) is a challenging setting where existing off-policy actor-critic methods perform poorly due to the overestimation of out-of-distribution state-action pairs. Thus, various additional augmentations are…

Machine Learning · Computer Science 2023-02-23 Zifeng Zhuang , Kun Lei , Jinxin Liu , Donglin Wang , Yilang Guo

The proximal policy optimization (PPO) algorithm stands as one of the most prosperous methods in the field of reinforcement learning (RL). Despite its success, the theoretical understanding of PPO remains deficient. Specifically, it is…

Machine Learning · Computer Science 2023-06-09 Han Zhong , Tong Zhang

Reinforcement Learning (RL) agents can solve diverse tasks but often exhibit unsafe behavior. Constrained Markov Decision Processes (CMDPs) address this by enforcing safety constraints, yet existing methods either sacrifice reward…

Machine Learning · Computer Science 2025-08-18 Nikola Milosevic , Johannes Müller , Nico Scherf

In recent years, reinforcement learning (RL) has gained increasing attention in control engineering. Especially, policy gradient methods are widely used. In this work, we improve the tracking performance of proximal policy optimization…

Machine Learning · Computer Science 2021-07-21 Jana Mayer , Johannes Westermann , Juan Pedro Gutiérrez H. Muriedas , Uwe Mettin , Alexander Lampe

Inverse Reinforcement Learning (IRL) learns a reward function to explain expert demonstrations. Modern IRL methods often use the adversarial (minimax) formulation that alternates between reward and policy optimization, which often lead to…

Machine Learning · Computer Science 2025-10-14 Yang Chen , Menglin Zou , Jiaqi Zhang , Yitan Zhang , Junyi Yang , Gael Gendron , Libo Zhang , Jiamou Liu , Michael J. Witbrock

Proximal policy optimization (PPO) is one of the most popular state-of-the-art on-policy algorithms that has become a standard baseline in modern reinforcement learning with applications in numerous fields. Though it delivers stable…

Machine Learning · Computer Science 2025-02-25 Qisai Liu , Zhanhong Jiang , Hsin-Jung Yang , Mahsa Khosravi , Joshua R. Waite , Soumik Sarkar