Adaptive Diffusion Policy Optimization for Robotic Manipulation
Huiyun Jiang, Zhuang Yang
TL;DR
This work tackles the challenge of fast and stable optimization of diffusion-based policies in robotic reinforcement learning. It proposes ADPO, an Adam-based Diffusion Policy Optimization framework that employs adaptive gradient updates with a discount factor to interpolate among optimizers and Katyusha-style momentum to reduce noise-induced oscillations. The approach is validated by embedding ADAPG into six diffusion-based RL methods (DPPO, DIPO, IDQL, DAWR, QSM, DQL) and testing on OpenAI Gym and ROBOMIMIC robotic manipulation tasks, where ADPO variants achieve superior or comparable performance and improved stability. The paper also conducts a thorough hyperparameter study, revealing robust settings for $\varepsilon$ and task-dependent settings for $\omega$, providing actionable guidance for practitioners.
Abstract
Recent studies have shown the great potential of diffusion models in improving reinforcement learning (RL) by modeling complex policies, expressing a high degree of multi-modality, and efficiently handling high-dimensional continuous control tasks. However, there is currently limited research on how to optimize diffusion-based polices (e.g., Diffusion Policy) fast and stably. In this paper, we propose an Adam-based Diffusion Policy Optimization (ADPO), a fast algorithmic framework containing best practices for fine-tuning diffusion-based polices in robotic control tasks using the adaptive gradient descent method in RL. Adaptive gradient method is less studied in training RL, let alone diffusion-based policies. We confirm that ADPO outperforms other diffusion-based RL methods in terms of overall effectiveness for fine-tuning on standard robotic tasks. Concretely, we conduct extensive experiments on standard robotic control tasks to test ADPO, where, particularly, six popular diffusion-based RL methods are provided as benchmark methods. Experimental results show that ADPO acquires better or comparable performance than the baseline methods. Finally, we systematically analyze the sensitivity of multiple hyperparameters in standard robotics tasks, providing guidance for subsequent practical applications. Our video demonstrations are released in https://github.com/Timeless-lab/ADPO.git.
