Title: Predictive Embedding as Latent Action: Towards VLA Pretraining in the Wild
Primary area: applications to robotics, autonomy, planning
Keywords: Predictive Embedding, VLA pretraining

Abstract: Vision-Language-Action models (VLAs) show promise for scalable robot learning, yet their progress is limited by small, narrow robot datasets. Human manipulation videos could provide richer learning material of skills, but current methods face a dilemma: either use expensive, precise labeled data with a limited scope, or abundant in-the-wild videos without hand tracking labels. We propose PELA, a pretraining framework that learns human motions by creating Predictive Embeddings that align with Latent Actions. Instead of trying to reconstruct every dynamics detail, PELA focuses on motion patterns that can be predicted from context and reflect real physical interaction. This creates a latent action space that captures motion dynamics across heterogeneous data sources. We build UniHand-Mix, a large hybrid dataset combining 5M carefully labeled lab recordings pairs with 2.5M pairs from in-the-wild human videos (7.5M total samples, >2,000 hours). This provides both reliable training signals and diverse real-world scenarios for large-scale learning. Our experiments show PELA generates realistic hand motions in both controlled and in-the-wild scenarios, and significantly improves downstream robot manipulation performance. The results demonstrate that predictive embeddings offer a practical route to scaling VLA pretraining using abundant human data.