Model Q-II: An Underactuated Hand with Enhanced Grasping Modes and Primitives for Dexterous Manipulation

This paper introduces Model Q-II, an enhanced underactuated robotic hand designed to improve dexterous manipulation through expanded grasping modes and manipulation primitives. The Model Q-II incorporates tripod and enhanced power grasping modes, achieving increased versatility without adding additional actuators. The design employs passive mechanisms, such as lateral contact walls and a finger-locking system, to facilitate seamless transitions between modes, enabling precise pinch-to-tripod and pinch-to-power gating. These enhancements allow the hand to perform complex in-hand manipulations, including multi-directional object positioning. Theoretical analysis, simulations, and experimental evaluations validate the hand's performance, demonstrating improved grasping force, range, and manipulation capabilities. The results highlight Model Q-II's ability to handle various tasks, offering a robust, cost-effective solution for applications requiring both precise and powerful grasping.