Abstract

World action models (WAMs) combine robot action generation with future state prediction. Existing WAMs typically predict videos or learned visual latents, which represent interaction geometry only implicitly and may retain appearance information unrelated to control. We introduce SkeleWAM, a compact WAM that represents a manipulation scene as a sparse 3D skeleton composed of robot joints, object centers, and interaction points. Constructed online from current RGB-D observations and robot proprioception, the skeleton provides a unified geometric state for action generation and future skeleton prediction. Future skeleton prediction provides additional geometric supervision for action learning without requiring visual reconstruction. At inference, SkeleWAM generates actions directly from the current skeleton and language instruction, while Medoid Action Consensus (MAC) serves as an auxiliary consensus strategy for stochastic action samples. On LIBERO-Plus, SkeleWAM achieves an overall success rate of 85.9% with 57.1M parameters, outperforming Cosmos-Policy by 3.7 percentage points. These results demonstrate that sparse 3D robot--object structure provides an effective state space for robust and parameter-efficient world action learning. The project is available at https://skelewam-project.github.io/.

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Open access
Green open access

Cite this article

APA 7

Sheng, J., Wang, H., & Liu, M. (2026). SkeleWAM: Skeleton World-Action Modeling for Efficient Robotic Manipulation. https://omanscience.com/en/articles/skelewam-skeleton-world-action-modeling-for-efficient-robotic-manipulation

MLA 9

Sheng, Juyi, et al. "SkeleWAM: Skeleton World-Action Modeling for Efficient Robotic Manipulation." https://omanscience.com/en/articles/skelewam-skeleton-world-action-modeling-for-efficient-robotic-manipulation.

Chicago (author–date)

Sheng, Juyi, Hua Wang, and Mengyuan Liu. 2026. "SkeleWAM: Skeleton World-Action Modeling for Efficient Robotic Manipulation." https://omanscience.com/en/articles/skelewam-skeleton-world-action-modeling-for-efficient-robotic-manipulation.

Harvard

Sheng, J., Wang, H. and Liu, M. (2026) 'SkeleWAM: Skeleton World-Action Modeling for Efficient Robotic Manipulation', Available at: https://omanscience.com/en/articles/skelewam-skeleton-world-action-modeling-for-efficient-robotic-manipulation.

Vancouver

Sheng J, Wang H, Liu M. SkeleWAM: Skeleton World-Action Modeling for Efficient Robotic Manipulation. https://omanscience.com/en/articles/skelewam-skeleton-world-action-modeling-for-efficient-robotic-manipulation

IEEE

J. Sheng, H. Wang, and M. Liu, "SkeleWAM: Skeleton World-Action Modeling for Efficient Robotic Manipulation," https://omanscience.com/en/articles/skelewam-skeleton-world-action-modeling-for-efficient-robotic-manipulation.