Frontiers in Robotics and AI (Aug 2023)

Learning to reason over scene graphs: a case study of finetuning GPT-2 into a robot language model for grounded task planning

  • Georgia Chalvatzaki,
  • Georgia Chalvatzaki,
  • Georgia Chalvatzaki,
  • Ali Younes,
  • Daljeet Nandha,
  • An Thai Le,
  • Leonardo F. R. Ribeiro,
  • Iryna Gurevych,
  • Iryna Gurevych

DOI
https://doi.org/10.3389/frobt.2023.1221739
Journal volume & issue
Vol. 10

Abstract

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Long-horizon task planning is essential for the development of intelligent assistive and service robots. In this work, we investigate the applicability of a smaller class of large language models (LLMs), specifically GPT-2, in robotic task planning by learning to decompose tasks into subgoal specifications for a planner to execute sequentially. Our method grounds the input of the LLM on the domain that is represented as a scene graph, enabling it to translate human requests into executable robot plans, thereby learning to reason over long-horizon tasks, as encountered in the ALFRED benchmark. We compare our approach with classical planning and baseline methods to examine the applicability and generalizability of LLM-based planners. Our findings suggest that the knowledge stored in an LLM can be effectively grounded to perform long-horizon task planning, demonstrating the promising potential for the future application of neuro-symbolic planning methods in robotics.

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