What Can a VLA Learn from the Agent That Calls It? Task-Level Experience Distillation for Embodied Navigation

원문 초록

Navigation agents use a large language model (LLM) planner to call a vision-language-action (VLA) model. Each episode needs the LLM, adding cost and delay. We distill successful agent experience into the VLA instead of distilling the planner. The VLA then navigates alone at test time. Agent sessions are not VLA demonstrations. They include motions driven by planner tools and sub-instructions, along with detours. We present H2E, a task-level experience distillation method that converts these sessions into VLA training data. Every motion becomes a VLA action under the original task instruction, with the resulting poses as targets. H2E masks the loss on steps that move away from the goal. It labels every visited state within 1 m of the goal as a stop. We then update the VLA with low-rank adaptation. The VLA learns to stop at the goal and find goals the base model never reaches. On all 3,189 REVERIE-CE val-unseen episodes, H2E raises the success rate of an 8B VLA from 35.0% to 44.9%.