DELTA: Decomposed Efficient Long-Term Robot Task Planning using Large Language Models
Yuchen Liu, Luigi Palmieri, Sebastian Koch, Ilche Georgievski, Marco Aiello
TL;DR
DELTA addresses the challenge of long-horizon robot task planning with large language models by grounding LLM outputs in 3D scene graphs and decomposing long-term goals into sub-goals. The method generates formal domain and problem descriptions in PDDL, prunes scene graphs to essential items, and solves sub-problems autoregressively with an automated planner, concatenating executable sub-plans. Across five domains and multiple scenes, DELTA achieves higher success rates and orders-of-magnitude faster planning times than four strong baselines, demonstrating the value of environment-grounded LLM planning and goal decomposition. The approach offers a scalable, automatic planning pipeline with strong generalization, and points to future work on handling dynamic uncertainties and real-world validation.
Abstract
Recent advancements in Large Language Models (LLMs) have sparked a revolution across many research fields. In robotics, the integration of common-sense knowledge from LLMs into task and motion planning has drastically advanced the field by unlocking unprecedented levels of context awareness. Despite their vast collection of knowledge, large language models may generate infeasible plans due to hallucinations or missing domain information. To address these challenges and improve plan feasibility and computational efficiency, we introduce DELTA, a novel LLM-informed task planning approach. By using scene graphs as environment representations within LLMs, DELTA achieves rapid generation of precise planning problem descriptions. To enhance planning performance, DELTA decomposes long-term task goals with LLMs into an autoregressive sequence of sub-goals, enabling automated task planners to efficiently solve complex problems. In our extensive evaluation, we show that DELTA enables an efficient and fully automatic task planning pipeline, achieving higher planning success rates and significantly shorter planning times compared to the state of the art. Project webpage: https://delta-llm.github.io/
