Closed-loop VLA training
Several papers treat supervised imitation as an incomplete training signal for robot policies. dVLA-RL applies proximal policy optimization (PPO) to the sampled denoising path of a discrete diffusion VLA, which gives the policy a usable likelihood during multi-step action generation. It reports 99.7% average success on LIBERO and raises an MM-ACT backbone on RoboTwin 2.0 from 61.4% to 92.0% average success.
Flatness Preserves Instruction Following attacks a different failure mode: small robot datasets can make a VLA ignore changed language instructions. Adding sharpness-aware minimization (SAM) during finetuning improves counterfactual instruction following without new data, including 47.8% success on LIBERO-CF compared with 13.2% for the default π0.5 finetune. RECALL adds a deployment loop: collect recovery demonstrations at high-uncertainty states, then train with replay to avoid forgetting. Its strongest setting reaches 72.4% overall LIBERO-10 success, compared with 60.2% for matched passive collection.