AAMAS Conference 2026 Conference Paper
Plan-and-Execute: LLM-Guided Reinforcement Learning with Cross-Modal Fusion for Long-Sequence Decision Making
- Yadong Li
- Tong Zhang
- Zhen Cui
We introduce Plan-and-Execute (PLEX), a novel framework that synergies the abstract reasoning capabilities of large language models (LLMs) with the grounded reinforcement learning (RL). In this architecture, an LLM serves as a dynamic planner, iteratively decomposing complex language instructions into structured subgoal sequences. A dedicated RL agent, leveraging cross-modal attention mechanism, then executes these subgoals by fusing language instructions with high-dimensional visual observations to learn and optimize its decision-making policies. This hierarchical coordination enables our agent to master long-horizon tasks through a tight loop of reasoning and grounded interaction. Comprehensive evaluation in the MiniGrid and MiniHack environment confirms that PLEX achieves a significant performance improvement over existing methods across diverse scenarios. The PLEX exhibits superior sample efficiency, particularly in complex, long-horizon tasks that require sustained reasoning and action sequences.