Coarse-to-fine action generation
Two manipulation papers treat action structure as a control problem. Libra-VLA splits prediction into discrete macro-direction intent and continuous fine control, then runs its heavier planner less often through an intent buffer. It reports 97.2% average success on LIBERO and 79.5% zero-shot success on LIBERO-Plus.
CF-VLA applies a similar coarse-then-fine idea to flow-based action sampling. It uses two function evaluations: one coarse action-aware start point and one local correction. The reported trade-off is concrete: 96.5 average LIBERO success at NFE=2, 75.4% lower action sampling latency, and 83.0 average success in real-robot experiments.