A study of a robotic hand with tendon driven fingers

Robotica ◽  
2014 ◽  
Vol 33 (5) ◽  
pp. 1034-1048 ◽  
Author(s):  
Cesare Rossi ◽  
Sergio Savino ◽  
Vincenzo Niola ◽  
Stefano Troncone

SUMMARYIn the present paper, a model of an underactuated robotic hand with tendon driven fingers is proposed. The aim of the project was to study the feasibility of building a mechanical hand with four or five fingers, the movement of which is achieved using a single linear actuator. The mechanism was first modelled in order to study the possible improvement in the ability of a “robotic hand” powered with a single actuator in regard to grasping objects with complex shapes and also in achieving a strong grip on objects. Next, a model of the finger was studied in order to optimize of its parameters. Finally, a five-fingered robotic hand was modelled for potential application as a human hand prosthesis. Our studies on the dynamic and kinematic behaviour of a single finger mechanism permitted us to make the first prototypes of the mechanism. In addition to modelling studies, we also present a prototype of the modelled robotic hand that was developed in order to optimize functionality and simplicity of construction.

Author(s):  
C Cosenza ◽  
V Niola ◽  
S Savino

The development of suitable models for mechanical fingers, whether they are part of prosthetic device or of a robotic hand, is a powerful tool to predict the behaviour of their components since the early stages of design, especially for underactuated mechanisms. Experimental data can improve the reliability of such models and promote their application to build proper control strategies especially for prosthetic hands. Here, we have developed a multi-jointed model of a mechanical finger. The finger is part of the Federica hand: an underactuated mechanical hand that was conceived for prosthetic purpose. The model accounts for friction phenomena in the finger and it is tuned with experimental data acquired through a digital image correlation device. The model allowed us to write kinematics relations of the phalanges and evaluate finger configurations in relation to the closure velocity. Moreover, it was possible to estimate the tendon force and the work analysis occurring during the closure tasks, both in free mode and in presence of objects.


Author(s):  
Abhay Patil

Abstract: There are roughly 21 million handicapped people in India, which is comparable to 2.2% of the complete populace. These people are affected by various neuromuscular problems. To empower them to articulate their thoughts, one can supply them with elective and augmentative correspondence. For this, a Brain-Computer Interface framework (BCI) has been assembled to manage this specific need. The basic assumption of the venture reports the plan, working just as a testing impersonation of a man's arm which is intended to be powerfully just as kinematically exact. The conveyed gadget attempts to take after the movement of the human hand by investigating the signs delivered by cerebrum waves. The cerebrum waves are really detected by sensors in the Neurosky headset and produce alpha, beta, and gamma signals. Then, at that point, this sign is examined by the microcontroller and is then acquired onto the engineered hand by means of servo engines. A patient that experiences an amputee underneath the elbow can acquire from this specific biomechanical arm. Keywords: Brainwaves, Brain Computer Interface, Arduino, EEG sensor, Neurosky Mindwave Headset, Robotic arm


2017 ◽  
Vol 139 (10) ◽  
Author(s):  
Taylor D. Niehues ◽  
Ashish D. Deshpande

The anatomically correct testbed (ACT) hand mechanically simulates the musculoskeletal structure of the fingers and thumb of the human hand. In this work, we analyze the muscle moment arms (MAs) and thumb-tip force vectors in the ACT thumb in order to compare the ACT thumb's mechanical structure to the human thumb. Motion data are used to determine joint angle-dependent MA models, and thumb-tip three-dimensional (3D) force vectors are experimentally analyzed when forces are applied to individual muscles. Results are presented for both a nominal ACT thumb model designed to match human MAs and an adjusted model that more closely replicates human-like thumb-tip forces. The results confirm that the ACT thumb is capable of faithfully representing human musculoskeletal structure and muscle functionality. Using the ACT hand as a physical simulation platform allows us to gain a better understanding of the underlying biomechanical and neuromuscular properties of the human hand to ultimately inform the design and control of robotic and prosthetic hands.


Robotics ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 67 ◽  
Author(s):  
Godwin Ponraj Joseph Vedhagiri ◽  
Avataram Venkatavaradan Prituja ◽  
Changsheng Li ◽  
Guoniu Zhu ◽  
Nitish V. Thakor ◽  
...  

This paper is an extension of our previous work about a modular anthropomorphic robotic hand with soft enhancements focusing on simultaneous pinch grasp and suction-based object manipulations. The base structure is a tendon-driven robotic hand comprising five fingers and a palm. Each finger consists of two rigid links covered with soft enhancements. The soft enhancements are like the skin and tissues of the robotic hand. The tip of the finger is equipped with a suction module which can be actuated by regulating negative pressure to the soft layers. While our previous work dealt with the rationale behind and the structure of the modular design with kinematic analysis, this paper focuses on analyzing two specific capabilities of the gripper—pinch grasp and suction modality. Experiments validate that the proposed gripper together with the soft enhancement layers is capable of performing delicate single finger suction-based manipulation tasks and two-finger pinch grasp tasks.


Author(s):  
Thomas E. Pillsbury ◽  
Ryan M. Robinson ◽  
Norman M. Wereley

Pneumatic artificial muscles (PAMs) are used in robotics applications for their light-weight design and superior static performance. Additional PAM benefits are high specific work, high force density, simple design, and long fatigue life. Previous use of PAMs in robotics research has focused on using “large,” full-scale PAMs as actuators. Large PAMs work well for applications with large working volumes that require high force and torque outputs, such as robotic arms. However, in the case of a compact robotic hand, a large number of degrees of freedom are required. A human hand has 35 muscles, so for similar functionality, a robot hand needs a similar number of actuators that must fit in a small volume. Therefore, using full scale PAMs to actuate a robot hand requires a large volume which for robotics and prosthetics applications is not feasible, and smaller actuators, such as miniature PAMs, must be used. In order to develop a miniature PAM capable of producing the forces and contractions needed in a robotic hand, different braid and bladder material combinations were characterized to determine the load stroke profiles. Through this characterization, miniature PAMs were shown to have comparably high force density with the benefit of reduced actuator volume when compared to full scale PAMs. Testing also showed that braid-bladder interactions have an important effect at this scale, which cannot be modeled sufficiently using existing methods without resorting to a higher-order constitutive relationship. Due to the model inaccuracies and the limited selection of commercially available materials at this scale, custom molded bladders were created. PAMs created with these thin, soft bladders exhibited greatly improved performance.


Symmetry ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1470 ◽  
Author(s):  
Flaviu Ionuț Birouaș ◽  
Radu Cătălin Țarcă ◽  
Simona Dzitac ◽  
Ioan Dzitac

Robotic exoskeletons are a trending topic in both robotics and rehabilitation therapy. The research presented in this paper is a summary of robotic exoskeleton development and testing for a human hand, having application in motor rehabilitation treatment. The mechanical design of the robotic hand exoskeleton implements a novel asymmetric underactuated system and takes into consideration a number of advantages and disadvantages that arose in the literature in previous mechanical design, regarding hand exoskeleton design and also aspects related to the symmetric and asymmetric geometry and behavior of the biological hand. The technology used for the manufacturing and prototyping of the mechanical design is 3D printing. A comprehensive study of the exoskeleton has been done with and without the wearer’s hand in the exoskeleton, where multiple feedback sources are used to determine symmetric and asymmetric behaviors related to torque, position, trajectory, and laws of motion. Observations collected during the experimental testing proved to be valuable information in the field of augmenting the human body with robotic devices.


Sign in / Sign up

Export Citation Format

Share Document