Real-Time Force Regulation for Whole-Hand Dexterous Grasping

Sang Min Kim, Alexander Alexiev, Tzu-Yuan Lin, Sangbae Kim, Young Min Kim, Yonghyeon Lee · N/A · 2026

Summary

Abstract Summary

Robust dexterous grasping requires maintaining physical stability despite contacts interactively evolving across the entire hand. A precomputed force distribution can easily fail under object motion, modeling errors, or external disturbances. In this paper, we present a framework for real-time force regulation over dynamically changing whole-hand contacts. Our method geometrically estimates contacts across all hand links using a tracked object model and proprioception, without requiring tactile sensing at those contacts. It repeatedly recomputes the desired contact-force distribution subject to friction constraints, actuator limits, and an actuation-consistency constraint motivated by classical whole-limb force analysis. We integrate this force-regulation controller with reactive reaching, enabling the hand to acquire a grasp, maintain it under disturbances, and regrasp after losing the object. Simulation experiments without gravity demonstrate improved grasp retention over fixed-allocation and fingertip-only execution under controlled perturbations, while real-world experiments on a 27-DoF arm-hand system demonstrate grasp maintenance and recovery under human-applied disturbances as contacts evolve across the whole hand. Project page: https://sangminkim-99.github.io/reactive-grasp-whole-hand/

Key Points

Robust dexterous grasping requires maintaining physical stability despite contacts interactively evolving across the entire hand.
A precomputed force distribution can easily fail under object motion, modeling errors, or external disturbances.
In this paper, we present a framework for real-time force regulation over dynamically changing whole-hand contacts.
Our method geometrically estimates contacts across all hand links using a tracked object model and proprioception, without requiring tactile sensing at those contacts.
It repeatedly recomputes the desired contact-force distribution subject to friction constraints, actuator limits, and an actuation-consistency constraint motivated by classical whole-limb force analysis.

Methodology

Our goal is to regulate contact forces in real time as the hand–object contact configuration evolves. We consider a dexterous hand with $n_{h}$ actuated degrees of freedom (DoF) and joint configuration $q\in\mathbb{R}^{n_{h}}$, together with a target object whose 6-DoF pose is continuously tracked.

The object mesh $\mathcal{M}$ is obtained from a CAD model in simulation or from an offline reconstruction of the physical object.

Methodology — Real-Time Force Regulation for Whole-Hand Dexterous Grasping — Fig. 2: Visualization of perturbation-test protocol. Starting from a stored grasp, the controller regulates the contact forces (a, b), and a force equal to 10% of the object weight is applied along one of $\pm x,\pm y,\pm z$ at a time (c). A spring–damper wrench then pulls the object toward a pose rotated by $\theta$ about a random axis (d; grey/red dashed outline: before/after), and the load test is repeated (e). A trial succeeds only if the object is held through all six directions.

Experiments and Results

We evaluate the framework in simulation, where controlled perturbations allow quantitative comparison and ablation (Secs. IV-A and IV-B ), and on a physical arm–hand system under human disturbances (Sec. IV-C ). Unless otherwise noted, we use $\mu=0.7$, $f_{n,\min}=10$ N, $\tau_{\max}=0.2$ N$\cdot$m per joint, $d_{\mathrm{thresh}}=1$ cm, $K=5$, and $\epsilon_{\mathrm{margin}}=0.5$ N.

Sources and Demonstrations

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