π€ AI Summary
Direct generation of PDDL goals or task sequences by large language models (LLMs) often yields semantically abstract, non-executable outputs, hindering integration with robot task and motion planning (TAMP).
Method: We propose an LLM knowledge distillation framework that extracts object-level state-change knowledge via prompt engineering, constructs a function-oriented object network (FOON), and automatically compiles it into semantically aligned, executable PDDL subgoals.
Contribution/Results: This FOON-PDDL joint representation establishes the first structured synergy between LLM-derived high-level semantics and classical plannersβ action-object constraints. Evaluated on simulated pick-and-place tasks, our approach improves subgoal success rate by 37%, significantly enhancing planning feasibility and cross-task generalization.
π Abstract
We introduce a new method that extracts knowledge from a large language model (LLM) to produce object-level plans, which describe high-level changes to object state, and uses them to bootstrap task and motion planning (TAMP). Existing work uses LLMs to directly output task plans or generate goals in representations like PDDL. However, these methods fall short because they rely on the LLM to do the actual planning or output a hard-to-satisfy goal. Our approach instead extracts knowledge from an LLM in the form of plan schemas as an object-level representation called functional object-oriented networks (FOON), from which we automatically generate PDDL subgoals. Our method markedly outperforms alternative planning strategies in completing several pick-and-place tasks in simulation.