Diffusion policy with Q-ensemble for offline reinforcement learning
摘要
Offline reinforcement learning (ORL), with the aim of learning optimal policies from offline datasets, is an important paradigm of RL. Recently, Diffusion-QL has significantly boosted the performance of offline RL using a conditional diffusion model to represent RL policy. However, experimental results showed that normalized Q-value in the Diffusion-QL significantly reduced offline RL’s performance. To solve this problem, we proposed a Diffusion Policy with Q-Ensemble (DPQE) in this study. The DPQE employs the Q-ensemble method to mitigate the overestimation of Q-values on Out-Of-Distribution actions. It uses the variance of Q-ensemble to adaptively adjust the weight of the Q-value to balance behavior cloning and Q-learning term. In addition, an ensemble gradient diversification regularization term is introduced to the naive RL loss to improve the stability of the training process. Our approach is evaluated on the D4RL Gym-MuJoCo benchmarks and experimental results outperform the State-Of-The-Art offline RL algorithms.