TacHair: Tactile Contact-Distribution Guided Online Correction for Robotic Hair Stroking and Perception

TacHair: Tactile Contact-Distribution Guided Online Correction for Robotic Hair Stroking and Perception

Ruiyi Hu, Yongqiang Zhao, Daniel Bak, Yupeng Wang, Xuyang Zhang, Shan Luo · N/A · 2026

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Summary

Hair stroking is common in daily grooming and personal care, and is also widely used in hair-product evaluation, motivating robots with similar physical interaction capabilities.

Abstract Summary

Hair stroking is common in daily grooming and personal care, and is also widely used in hair-product evaluation, motivating robots with similar physical interaction capabilities. Existing robotic hair-care and surface-following methods mainly rely on trajectory planning, compliance, force regulation, or tactile-conditioned policies, but deformable hair can remain in contact while gradually drifting across the end-effector, making local interaction difficult to regulate. We propose TacHair, a tactile contact-distribution guided online correction framework that represents high-resolution tactile observations as a spatial hair-contact distribution. A visuotactile imitation policy generates the nominal stroking motion, while a separately trained residual module corrects local contact deviations, separating task progression from contact recovery. We evaluate TacHair in 525 real-robot trials across five head geometries and three hair conditions. A successful stroke requires both sufficient task progression and contact maintenance; our method improves success from 42.9% to 62.3% and contact maintenance from 59.4% to 88.0% over the same visuotactile policy without correction. These results demonstrate spatial tactile contact distributions as an effective feedback representation for contact-preserving interaction with deformable and visually occluded surfaces. Demos, code, and datasets are available at https://tachair.github.io.

Key Points

  • Hair stroking is common in daily grooming and personal care, and is also widely used in hair-product evaluation, motivating robots with similar physical interaction capabilities.
  • Existing robotic hair-care and surface-following methods mainly rely on trajectory planning, compliance, force regulation, or tactile-conditioned policies, but deformable hair can remain in contact while gradually drifting across the end-effector, making local interaction difficult to regulate.
  • We propose TacHair, a tactile contact-distribution guided online correction framework that represents high-resolution tactile observations as a spatial hair-contact distribution.
  • A visuotactile imitation policy generates the nominal stroking motion, while a separately trained residual module corrects local contact deviations, separating task progression from contact recovery.
  • We evaluate TacHair in 525 real-robot trials across five head geometries and three hair conditions

Methodology

As shown in Fig. 1 and Fig. 2 , we consider robotic hair stroking as a sequential control problem in which the robot moves from the crown toward the back of a hair-covered head while maintaining stable local contact throughout the motion. At time step $t$, the robot observes an external RGB image $I_{t}^{v}$, a high-resolution tactile image $I_{t}^{\tau}$, and its joint state $q_{t}$.

We denote the corresponding observation as $o_{t}=(I_{t}^{v},I_{t}^{\tau},q_{t})$. The robot action $a_{t}$ is a six-dimensional absolute joint-position target.

Methodology — TacHair: Tactile Contact-Distribution Guided Online Correction for Robotic Hair Stroking and Perception
Fig. 2: Overview of the proposed tactile contact-distribution guided hair-stroking framework. A nominal visuotactile policy takes RGB, tactile, robot-state, and language observations to generate absolute joint-position targets for the overall stroking motion. During execution, high-resolution tactile observations are mapped to a spatial hair-contact distribution, from which the normalized contact centroid is estimated. When the centroid deviates from the desired contact region, centroid-based routing activates the corresponding correction action, which predicts a short-horizon residual joint correction conditioned on the contact distribution and current robot state. The residual is added to the nominal joint target, and the resulting command is constrained and temporally smoothed before being sent to the robot. The nominal policy therefore drives stroke progression, while tactile feedback provides online local contact regulation.

Experiments

Our experimental system consists of perception, robotic, and teleoperation components, as shown in Fig. 3 . A GelSight Mini tactile sensor is mounted at the robot end effector, while a fixed third-person RGB camera provides global visual observations at $640\times 480$ resolution. We evaluate both the standard GelSight Mini membrane and a variant equipped with a custom silicone membrane.

The SO101 serves as the primary platform for quantitative evaluation, while the UR5e is used for additional cross-platform validation.

Experiments — TacHair: Tactile Contact-Distribution Guided Online Correction for Robotic Hair Stroking and Perception
Fig. 3: Experimental platforms. (a) The UR5e platform comprises a UR5e robot, a Meta Quest 3 teleoperation interface [ 24 ] , an external RGB camera, and an end-effector-mounted GelSight Mini. (b) The SO101 platform comprises an SO101 leader–follower pair [ 25 ] , the same external RGB camera used in the UR5e platform, and a GelSight Mini mounted on the follower end effector. Both platforms interact with a secured hair-covered headform. The quantitative experiments reported in this work were conducted using the SO101 platform.

Sources and Demonstrations

Figures are reproduced from Hu et al. See the full paper for experimental details and the project page, when the paper links one, for demonstrations and videos.

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