Training an agent to solve control tasks directly from high-dimensional images with model-free reinforcement learning (RL) has proven difficult. The agent needs to learn a latent representation together with a control policy to perform the task. Fitting a high-capacity encoder using a scarce reward signal is not only sample inefficient, but also prone to suboptimal convergence. Two ways to improve sample efficiency are to extract relevant features for the task and use off-policy algorithms. We dissect various approaches of learning good latent features, and conclude that the image reconstruction loss is the essential ingredient that enables efficient and stable representation learning in image-based RL. Following these findings, we devise an off-policy actor-critic algorithm with an auxiliary decoder that trains end-to-end and matches state-of-the-art performance across both model-free and model-based algorithms on many challenging control tasks. We release our code to encourage future research on image-based RL.

通过引入辅助损失以及消除后效性的影响，提出了一种简单且有效的方法，可以在MuJoCo控制任务上匹配最新的无模型和有模型算法，同时在观测噪声下表现出鲁棒性，并且过来了以往使用变分自动编码器所面临的发散问题。

提高基于图像的模型自由强化学习的样本效率