Constrained Contrastive Reinforcement Learning
Proceedings of The 14th Asian Conference on Machine Learning, PMLR 189:1070-1084, 2023.
Learning to control from complex observations remains a major challenge in the application of model-based reinforcement learning (MBRL). Existing MBRL methods apply contrastive learning to replace pixel-level reconstruction, improving the performance of the latent world model. However, previous contrastive learning approaches in MBRL fail to utilize task-relevant information, making it difficult to aggregate observations with the same task-relevant information but the different task-irrelevant information in latent space. In this work, we first propose Constrained Contrastive Reinforcement Learning (C2RL), an MBRL method that learns a world model through a combination of two contrastive losses based on latent dynamics and task-relevant state abstraction respectively, utilizing reward information to accelerate model learning. Then, we propose a hyperparameter $\beta$ to balance two kinds of contrastive losses to strengthen the representation ability of the latent dynamics. The experimental results show that our approach outperforms state-of-the-art methods in both the natural video and standard background setting on challenging DMControl tasks.