No Prior Mask: Eliminate Redundant Action for Deep Reinforcement Learning
This addresses a fundamental obstacle for deploying RL in real-world settings by reducing action redundancy, though it is an incremental improvement over existing methods.
The paper tackles the problem of large action spaces in reinforcement learning by proposing a redundant action filtering mechanism that eliminates repeated or invalid attempts without prior knowledge, achieving superior performance on high-dimensional, pixel-input, and stochastic problems.
The large action space is one fundamental obstacle to deploying Reinforcement Learning methods in the real world. The numerous redundant actions will cause the agents to make repeated or invalid attempts, even leading to task failure. Although current algorithms conduct some initial explorations for this issue, they either suffer from rule-based systems or depend on expert demonstrations, which significantly limits their applicability in many real-world settings. In this work, we examine the theoretical analysis of what action can be eliminated in policy optimization and propose a novel redundant action filtering mechanism. Unlike other works, our method constructs the similarity factor by estimating the distance between the state distributions, which requires no prior knowledge. In addition, we combine the modified inverse model to avoid extensive computation in high-dimensional state space. We reveal the underlying structure of action spaces and propose a simple yet efficient redundant action filtering mechanism named No Prior Mask (NPM) based on the above techniques. We show the superior performance of our method by conducting extensive experiments on high-dimensional, pixel-input, and stochastic problems with various action redundancy. Our code is public online at https://github.com/zhongdy15/npm.