Hierarchical Agents by Combining Language Generation and Semantic Goal Directed RL

Bharat Prakash, Nicholas R Waytowich, Tim Oates, Tinoosh Mohsenin

Keywords: Hierarchical Agents, reinforcement learning, language generation

TL;DR: An interpretable hierarchical agent framework by combining sub-goal generation using language and semantic goal directed reinforcement learning

Abstract: Learning to solve long horizon temporally extended tasks with reinforcement learning has been a challenge for several years now. We believe that it is important to leverage both the hierarchical structure of complex tasks and to use expert supervision whenever possible to solve such tasks. This work introduces an interpretable hierarchical agent framework by combining sub-goal generation using language and semantic goal directed reinforcement learning. We assume access to certain spatial and haptic predicates and construct a simple and powerful semantic goal space. These semantic goal representations act as an intermediate representation between language and raw states. We evaluate our framework on a robotic block manipulation task and show that it performs better than other methods, including both sparse and dense reward functions. We also suggest some next steps and discuss how this framework makes interaction and collaboration with humans easier.