SixthSense: Task-Agnostic Proprioception-Only Whole-Body Wrench Estimation for Humanoids

Xingzhou Chen; Xiayan Xu; Yan Ning; Jiyu Yu; Yizheng Zhang; Siyi Qian; Lingzhu Xiang; Jiahao Chen; Yuquan Wang; Haodong Zhang; Ling Shi

arXiv · 2605.01427

SixthSense: Task-Agnostic Proprioception-Only Whole-Body Wrench Estimation for Humanoids

Xingzhou Chen·Xiayan Xu·Yan Ning·Jiyu Yu·Yizheng Zhang·Siyi Qian·Lingzhu Xiang·Jiahao Chen·Yuquan Wang·Haodong Zhang·Ling Shi

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Abstract

Humanoid robots are entering our physical world at scale, yet as oversized toys--good at singing and dancing, but short on force-interaction capabilities for practical tasks. Bridging this gap necessitates prioritizing reliable contact perception as a fundamental requirement. Estimating external wrenches in humanoids is complicated by floating-base dynamics and indeterminate contact locations. Existing analytical frameworks require idealistic assumptions and hard-to-obtain measurements, which are often unavailable in practice. To bridge this gap, we propose SixthSense, a task-agnostic approach that infers whole-body contact timing, location, and wrenches from proprioception and IMU data alone. To capture the multi-modal dynamics between unstructured contact inputs and the uncertain motion outputs, we employ conditional flow matching to tokenize proprioceptive histories and estimate a spatiotemporally sparse contact-event flow. SixthSense serves as a plug-and-play perception module for applications including collision detection, physical human-robot interaction, and force-feedback teleoperation. Experiments across standing, walking, and whole-body motion-tracking policies showcased unprecedented performance in diverse behaviors.

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BibTeX RIS

Xingzhou Chen, Xiayan Xu, Yan Ning, Jiyu Yu, Yizheng Zhang, Siyi Qian, Lingzhu Xiang, Jiahao Chen, Yuquan Wang, Haodong Zhang, Ling Shi. 2026-05-02. SixthSense: Task-Agnostic Proprioception-Only Whole-Body Wrench Estimation for Humanoids. https://arxiv.org/abs/2605.01427

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