# NavBind Diagnoses Instruction-Action Binding at Route Forks in Navigation VLA Models

- Source: arXiv cs.RO
- Published: 2026-10-22T04:00:00.000Z
- RoboHot: https://robohot.news/en/items/fkqw2vikv430qgalho6e5khwj
- Original: https://arxiv.org/abs/2610.29203

## Summary

NavBind proposes a method for diagnosing whether navigation vision-language-action (VLA) models truly follow instructions: with the navigation context fixed, it checks whether changing the instruction affects the probability distribution of actions. The authors recombined route-aligned instruction segments from R2R-CE and RxR-CE to construct 3,252 route-fork contexts, each pairing two full instructions that share a description of the route already traveled but specify different branches, and evaluated them under the same agent state and navigation history.