LLM Augmented Hierarchical Agents
Bharat Prakash Tim Oates Tinoosh Mohsenin
Solving long-horizon, temporally-extended tasks using Reinforcement Learning
(RL) is challenging, compounded by the common practice of learning without
prior knowledge (or tabula rasa learning). Humans can generate and execute
plans with temporally-extended actions and quickly learn to perform new tasks
because we almost never solve problems from scratch. We want autonomous agents
to have this same ability. Recently, LLMs have been shown to encode a
tremendous amount of knowledge about the world and to perform impressive
in-context learning and reasoning. However, using LLMs to solve real world
problems is hard because they are not grounded in the current task. In this
paper we exploit the planning capabilities of LLMs while using RL to provide
learning from the environment, resulting in a hierarchical agent that uses LLMs
to solve long-horizon tasks. Instead of completely relying on LLMs, they guide
a high-level policy, making learning significantly more sample efficient. This
approach is evaluated in simulation environments such as MiniGrid, SkillHack,
and Crafter, and on a real robot arm in block manipulation tasks. We show that
agents trained using our approach outperform other baselines methods and, once
trained, don't need access to LLMs during deployment.