AION
Research paperRobotics & Embodied AI1 source · Oct 8, 2026

PathTime-VLA: Path-Time Decoupling for Factorized Post-Training of Vision-Language-Action Policies

Vision-Language-Action (VLA) policies typically predict actions at fixed time intervals, coupling the route a robot follows with its execution pace.

Key points

  • Our key insight is to bring the path-time parameterization of classical motion planning into the learned action representation of a VLA.
  • We introduce PathTime-VLA, which represents motion as a progress-indexed interaction path $X(s)$ and a positive interval-time profile.
  • This representation supports a staged post-training procedure: demonstrations and DAgger interventions establish a target-domain prior, Speed-DQN learns execution multipliers from robot interaction, and Path-AWR uses rollout outcomes to refine the diffusion path generator.
  • A path-conditioned action expert realizes the resulting motions while maintaining distinct learning interfaces for path generation and execution timing.

Sources (1)

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