TY - JOUR T1 - Exploring Stiffness Modulation in Prosthetic Hands and Its Perceived Function in Manipulation and Social Interaction. JF - Frontiers in Neurorobotics Y1 - 2020 A1 - Capsi-Morales, Patricia A1 - C. Piazza A1 - M. G. Catalano A1 - A. Bicchi A1 - G. Grioli KW - human-robot social interaction KW - impedance control KW - prosthetics KW - Soft robotics KW - task adaptability AB -

To physically interact with a rich variety of environments and to match situation-dependent requirements, humans adapt both the force and stiffness of their limbs. Reflecting this behavior in prostheses may promote a more natural and intuitive control and, consequently, improve prostheses acceptance in everyday life. This pilot study proposes a method to control a prosthetic robot hand and its impedance, and explores the utility of variable stiffness when performing activities of daily living and physical social interactions. The proposed method is capable of a simultaneous and proportional decoding of position and stiffness intentions from two surface electro-myographic sensors placed over a pair of antagonistic muscles. The feasibility of our approach is validated and compared to existing control modalities in a preliminary study involving one prosthesis user. The algorithm is implemented in a soft under-actuated prosthetic hand (SoftHand Pro). Then, we evaluate the usability of the proposed approach while executing a variety of tasks. Among these tasks, the user interacts with other 12 able-bodied subjects, whose experiences were also assessed. Several statistically significant aspects from the System Usability Scale indicate user's preference of variable stiffness control over low or high constant stiffness due to its reactivity and adaptability. Feedback reported by able-bodied subjects reveal a general tendency to favor soft interaction, i.e., low stiffness, which is perceived more human-like and comfortable. These combined results suggest the use of variable stiffness as a viable compromise between firm control and safe interaction which is worth investigating further.

VL - 14 UR - https://www.frontiersin.org/articles/10.3389/fnbot.2020.00033/full?&utm_source=Email_to_authors_&utm_medium=Email&utm_content=T1_11.5e1_author&utm_campaign=Email_publication&field=&journalName=Frontiers_in_Neurorobotics&id=503842 IS - 33 JO - Exploring Stiffness Modulation in Prosthetic Hand ER - TY - JOUR T1 - Variable Impedance Actuators: a Review JF - Robotics and Autonomous Systems Y1 - 2013 A1 - B. Vanderborght A1 - A Albu-Schaeffer A1 - A. Bicchi A1 - E. Burdet A1 - D. G. Caldwell A1 - R. Carloni A1 - M. G. Catalano A1 - O. Eiberger A1 - W. Friedl A1 - G. Ganesh A1 - M. Garabini A1 - M. Grebenstein A1 - G. Grioli A1 - S. Haddadin A1 - H. Hoppner A1 - A. Jafari A1 - M. Laffranchi A1 - D. Lefeber A1 - F. Petit A1 - S. Stramigioli A1 - N G Tsagarakis A1 - M. Van Damme A1 - R. Van Ham A1 - L. C. Visser A1 - S. Wolf KW - Robotics KW - Soft robotics KW - Variable Impedance Actuators AB -

Variable Impedance Actuators (VIA) have received increasing attention in recent years as many novel applications involving interactions with an unknown and dynamic environment including humans require actuators with dynamics that are not well-achieved by classical stiff actuators. This paper presents an overview of the different VIAs developed and proposes a classification based on the principles through which the variable stiffness and damping are achieved. The main classes are active impedance by control, inherent compliance and damping actuators, inertial actuators, and combinations of them, which are then further divided into subclasses. This classification allows for designers of new devices to orientate and take inspiration and users of VIA’s to be guided in the design and implementation process for their targeted application.

VL - 61 UR - http://www.sciencedirect.com/science/article/pii/S0921889013001188 IS - 12 N1 -

Available online 6 August 2013

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