Stroke-Based Variable-Damping with Force Attenuation for Capturing Large-Momentum Objects under Non-Zero Contact Velocity

Abstract

Basketball players catch fast passes, and porters unload goods with apparent ease. These actions demonstrate how humans rely on intelligent regulation strategies to drive muscle activity. Replicating similar dynamic responses and strong impact absorption in robotics, however, remains a major challenge. Classical impedance control requires a trade-off between compliance and stability in high-impact interactions, which limits dynamic performance. To address this issue, this paper proposes a Stroke-based Variable Damping Model (SVDM), which adjusts the damping coefficient adaptively according to the position error relative to the contact point. In addition, a Force Attenuation (FA) strategy is applied to the external forces injected into SVDM, resulting in the SVDM with Force Attenuation (FA-SVDM). Based on human biomechanical principles, we fabricated a 4-DOF robotic manipulator using 3D printing technology. Using FA-SVDM, the manipulator successfully captured a 1kg rigid sphere falling freely from 0.8m. Under identical conditions, it exhibits superior performance compared to various fixed-damping configurations. We further developed a 6-DOF robotic manipulator equipped with a dexterous hand in the widely-used MuJoCo engine, employing quadratic programming (QP) for pre-contact trajectory tracking and FA-SVDM for post-contact energy dissipation, ultimately achieving human-like compliant capture of high-momentum flying objects using a single arm with a half-prehensile strategy.