Accelerating Reinforcement Learning of Robotic Manipulations via Feedback from Large Language Models
Kun Chu, Xufeng Zhao, Cornelius Weber, Mengdi Li, Stefan Wermter
TL;DR
Reinforcement Learning in robotic manipulation often suffers from sample inefficiency and reward specification. Lafite-RL leverages Large Language Models to provide real-time evaluative feedback during RL, adding $r_{llm}$ to the environment reward as $r_t = r_{env} + r_{llm}$, using two prompts (Scene Observer and Motion Evaluator) to guide learning. On RLBench tasks with a Franka Panda, the approach yields higher success rates and faster learning than baselines, demonstrating the potential of LLM-guided, low-effort supervision for robotic manipulation. Overall, Lafite-RL shows that non-expert users can design prompts that enable LLMs to accelerate RL without direct low-level control, offering a scalable path toward interactive, data-efficient robotic learning.
Abstract
Reinforcement Learning (RL) plays an important role in the robotic manipulation domain since it allows self-learning from trial-and-error interactions with the environment. Still, sample efficiency and reward specification seriously limit its potential. One possible solution involves learning from expert guidance. However, obtaining a human expert is impractical due to the high cost of supervising an RL agent, and developing an automatic supervisor is a challenging endeavor. Large Language Models (LLMs) demonstrate remarkable abilities to provide human-like feedback on user inputs in natural language. Nevertheless, they are not designed to directly control low-level robotic motions, as their pretraining is based on vast internet data rather than specific robotics data. In this paper, we introduce the Lafite-RL (Language agent feedback interactive Reinforcement Learning) framework, which enables RL agents to learn robotic tasks efficiently by taking advantage of LLMs' timely feedback. Our experiments conducted on RLBench tasks illustrate that, with simple prompt design in natural language, the Lafite-RL agent exhibits improved learning capabilities when guided by an LLM. It outperforms the baseline in terms of both learning efficiency and success rate, underscoring the efficacy of the rewards provided by an LLM.
