Hierarchical Reinforcement Learning from Demonstration via Reachability-Based Reward Shaping

Hierarchical reinforcement learning (HRL) has achieved remarkable success and significant progress in complex and long-term decision-making problems. However, HRL training typically entails substantial computational costs and an enormous number of samples. One effective approach to tackle this challenge is hierarchical reinforcement learning from demonstrations (HRLfD), which leverages demonstrations to expedite the training process of HRL. The effectiveness of HRLfD is contingent upon the quality of the demonstrations; hence, suboptimal demonstrations may impede efficient learning. To address this issue, this paper proposes a reachability-based reward shaping (RbRS) method to alleviate the negative interference of suboptimal demonstrations for the HRL agent. The novel HRLfD algorithm based on RbRS is named HRLfD-RbRS, which incorporates the RbRS method to enhance the learning efficiency of HRLfD. Moreover, with the help of this method, the learning agent can explore better policies under the guidance of the suboptimal demonstration. We evaluate the proposed HRLfD-RbRS algorithm on various complex robotic tasks, and the experimental results demonstrate that our method outperforms current state-of-the-art HRLfD algorithms.