G-raph Hand: A Reconfigurable Anthropomorphic Hand With Hybrid Control and Lightweight Closure-Guided In-Hand Manipulation
Underactuated robotic hands offer high adaptability and control simplicity, yet limited dexterity often constrains their manipulation capabilities. To address this limitation, this article presents the G-raph hand, a reconfigurable anthropomorphic robotic hand designed for stable in-hand manipulation while maintaining control simplicity. Inspired by human manipulation, the design integrates underactuated fingers with a reconfigurable palm featuring a central compliant mechanism. This biomimetic architecture enables both active reconfiguration and passive adaptation by modulating finger-base distribution. Furthermore, a hybrid control scheme of in-hand manipulation is developed, combining position and force-feedback control with a lightweight gait planning strategy based on rapid closure property evaluations. By integrating motion intent and system stability, the proposed framework facilitates stable grasping and significant object reorientation. Kinematic workspace analysis and extensive multifinger manipulation experiments demonstrate that the G-raph hand and its associated control framework achieve reliable, flexible, and anthropomorphic performance in complex tasks.