Periodic Steady-State Control of a Handkerchief-Spinning Task Using a Parallel Anti-Parallelogram Tendon-driven Wrist

TL;DR

This paper presents a novel tendon-driven wrist design and control framework for precise, steady-state spinning of flexible objects like handkerchiefs, validated through hardware experiments achieving high accuracy and robustness.

Contribution

It introduces a new dexterous wrist structure and a control strategy for stable, high-dynamic manipulation of flexible objects, validated by experimental results.

Findings

Achieved approximately 99% unfolding ratio in experiments.

Fingertip tracking error of RMSE = 2.88 mm during high-speed spinning.

Validated the effectiveness of the control framework with hardware experiments.

Abstract

Spinning flexible objects, exemplified by traditional Chinese handkerchief performances, demands periodic steady-state motions under nonlinear dynamics with frictional contacts and boundary constraints. To address these challenges, we first design an intuitive dexterous wrist based on a parallel anti-parallelogram tendon-driven structure, which achieves 90 degrees omnidirectional rotation with low inertia and decoupled roll-pitch sensing, and implement a high-low level hierarchical control scheme. We then develop a particle-spring model of the handkerchief for control-oriented abstraction and strategy evaluation. Hardware experiments validate this framework, achieving an unfolding ratio of approximately 99% and fingertip tracking error of RMSE = 2.88 mm in high-dynamic spinning. These results demonstrate that integrating control-oriented modeling with a task-tailored dexterous wrist enables robust rest-to-steady-state transitions and precise periodic manipulation of highly flexible objects. More visualizations: https://slowly1113.github.io/icra2026-handkerchief/