🤖 AI Summary
Current robotic systems lack the ability to autonomously refine their policies during inference. This work proposes VERITAS, a framework that, for the first time, integrates a gradient-free visual verifier with a pretrained general-purpose policy to enable real-time action evaluation and correction during deployment—without requiring additional training or human intervention. By leveraging verification trajectories for offline self-improvement, the method substantially outperforms the original general policy. Moreover, through iterative fine-tuning on self-generated data, the system demonstrates continuous performance gains, ultimately achieving efficiency approaching that of expert demonstrations.
📝 Abstract
Robots deployed in the real world should learn from their experience and improve over time. This requires a mechanism of practicing and learning from feedback. In this paper, we propose VERITAS, a generator-verifier framework for generalist robot policies for inference-time policy steering and self-improvement. We use a pre-trained generalist robot policy as a ``generator'' and pair it with a gradient-free ``visual verifier'' that evaluates actions at inference time. This framework enables inference-time steering that improves policy performance without additional training. We demonstrate that inference-time verification consistently outperforms vanilla generalists without training on additional demonstration data. Additionally, we demonstrate that the verified rollouts provide effective supervision for offline policy improvement: policies fine-tuned on verified self-generated trajectories achieve consistent performance gains. Notably, we find that post-training with verified rollouts achieves comparable efficiency to expert demonstrations, while requiring no human interventions. Our results highlight inference-time verification as a practical and scalable mechanism for improving robotic policies during deployment.