Stroke-Based Variable-Damping with Force Attenuation for Capturing Large-Momentum Objects under Non-Zero Contact Velocity
Yang Chen, Junda Cao, Kai Gong, Yang Deng, Zhang Chen, Xudong Zheng, Zhili Hou, Bin Liang
AI summary
Problem
Capturing high-momentum flying objects requires mitigating severe impact forces while dissipating kinetic energy stably. Classical impedance control uses fixed parameters, forcing a restrictive trade-off between compliance and stability during dynamic interactions.
Approach
The method adaptively scales damping based on displacement from the contact point and applies a force attenuation mechanism to modulate external forces. This framework is rigorously proven stable and deployed for both physical and simulated robotic capture.
Key results
- Physical capture of a 1 kg sphere at ~4 m/s contact velocity
- Reduced peak impact forces and shorter deceleration strokes vs fixed damping
- Human-like compliant capture in MuJoCo simulation with a dexterous hand
- Rigorous passivity and asymptotic stability proofs for the control framework
Why it matters
Enables safer and more robust dynamic object capture for logistics automation, space debris collection, and advanced robotic manipulation.
Abstract
Basketball players catch fast passes, and porters unload goods without difficulty. 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 is theoretically sound and robust, but its fixed parameters require a trade-off between compliance and stability during high-impact interactions, which limits performance in dynamic scenarios. 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 hu- man 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, resulting in a relative velocity upon contact of approximately 4 m/s. 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.