Exploring Dexterous Manipulation Workspaces with the iHY Hand

Spherical Hands: Toward Underactuated, In-Hand Manipulation Invariant to Object Size and Grasp Location

“…Although the unactuated kinematic test setup in Section IV corroborated the spherical workspace center and the kinematic performance of the fingers designed for the spherical hands, it did not assess the effect of the new finger design and layout on grasp capability when compared to past work on underactuated precision manipulation [17]. The point contact assumption is difficult to reproduce in physical, in-hand manipulation trials, which generally require rolling [26] or soft contacts [27].…”

“…In practice, the authors have achieved stable precision grasps with underactuated hands through position-control of the actuation tendon lengths for each finger without tactile or visual feedback [17], [31]. The generated grasp force is a result of the fingers' reconfiguration from their free-swing trajectory due to the object contact constraints, as shown in Fig 11. The free-swing configuration f q i for the i th finger and some actuation tendon length a i is determined by:…”

“…Considerable research efforts have been applied to opposable thumb design in anthropomorphic hands [20], [21]. Qualitatively, past work in underactuated hands with flexural joints [17] suggested having an additional passive axis of rotation orthogonal to the standard design's joint axes, which are traditionally parallel with one another, could aid in pinch grasp adaptability and stability. Fig.…”

“…An initial evaluation of in-hand workspace in underactuated hands used two-link, linear, underactuated fingers with a revolute, proximal joint and a flexure-based distal joint [17]. An open-source, three-finger hand design [18] based on that work serves as the experimental hardware platform to evaluate the effects of mechanical design modifications on manipulation capabilities.…”

Design and experimental evaluation of a new modular underactuated multi-fingered robot hand

“…It requires only a small number of drive components and a simple control system to have a wide range of gripping and good load capacity. Examples of such a system include the shadow robot hand [9] developed by Shadow Company, the MPJ robot hand [10], the GUCA robot [11], the PCSS [12] and PASA robots [13] developed by Tsinghua University, the prosthetic hand [14] developed by Bogazici University, I-HYHAND [15] developed by Yale University, uGRIPP [16] developed by Tohoku University, the Pisa/IIT SoftHand 2 [17] developed by University of Pisa, and the ISR-SoftHand [18] developed by University of Coimbra.…”