Temporal GRPO: Beyond Trajectory-Level Credit in Vision-Language-Action Reinforcement Learning

arXiv:2608.13026v1 Announce Type: new Abstract: Outcome-driven reinforcement learning offers a scalable way to post-train vision-language-action (VLA) policies from sparse task-success feedback. In common GRPO-based VLA post-training, one rollout-level advantage is applied to every action in the tr