In this work, we propose a method to compute the stiffness of flexible joints and its realization in order to let the fingers track a certain predefined trajectory. We refer to tendon-driven, underactuated and passively compliant hands composed of deformable joints and rigid links. Specific stiffness and pre-form shapes can be assigned to the finger joints can be given s such that a single-cable actuation can be used. We firstly define a procedure to determine suitable joints stiffness and then we propose a possible realization of soft joints using rapid prototyping techniques. The stiffness computation is obtained leveraging on the the mechanics of tendon-driven hands and on compliant systems, while for its implementation beam theory has been exploited. We validate the proposed framework both in simulation and with experiments using the robotic Soft-SixthFinger, a wearable robot for grasping compensation in patients with a paretic hand, as a case study. The proposed framework can be used to design the stiffness of the passive joints in several model of underactuated tendon-driven soft hands so to improve their grasping capabilities.
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|Titolo:||On the role of stiffness design for fingertip trajectories of underactuated modular soft hands|
|Appare nelle tipologie:||4.1 Contributo in Atti di convegno|
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|ICRA_2017.pdf||Accepted version. European Union (EU), Horizon 2020 programme. European project “Synergy-based Open-source Foundations and Technologies for Prosthetics and RehabilitatiOn” (SoftPro), Research & Innovation Action, Grant Agreement n. 688857. © 2017 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works. Digital Object Identifier (DOI): 10.1109/ICRA.2017.7989354||N/A||PUBBLICO - Pubblico con Copyright||Open Access Visualizza/Apri|