scholarly journals Constraint Study for a Hand Exoskeleton: Human Hand Kinematics and Dynamics

2013 ◽  
Vol 2013 ◽  
pp. 1-17 ◽  
Author(s):  
Fai Chen Chen ◽  
Silvia Appendino ◽  
Alessandro Battezzato ◽  
Alain Favetto ◽  
Mehdi Mousavi ◽  
...  

In the last few years, the number of projects studying the human hand from the robotic point of view has increased rapidly, due to the growing interest in academic and industrial applications. Nevertheless, the complexity of the human hand given its large number of degrees of freedom (DoF) within a significantly reduced space requires an exhaustive analysis, before proposing any applications. The aim of this paper is to provide a complete summary of the kinematic and dynamic characteristics of the human hand as a preliminary step towards the development of hand devices such as prosthetic/robotic hands and exoskeletons imitating the human hand shape and functionality. A collection of data and constraints relevant to hand movements is presented, and the direct and inverse kinematics are solved for all the fingers as well as the dynamics; anthropometric data and dynamics equations allow performing simulations to understand the behavior of the finger.

Author(s):  
Yangmin Li ◽  
Qingsong Xu

A novel three-degrees-of-freedom (3-DOF) translational parallel manipulator (TPM) with orthogonally arranged fixed actuators is proposed in this paper. The mobility of the manipulator is analyzed via screw theory. The inverse kinematics, forward kinematics, and velocity analyses are performed and the singularities and isotropic configurations are investigated in details afterwards. Under different cases of physical constraints imposed by mechanical joints, the reachable workspace of the manipulator is geometrically generated and compared. Especially, it is illustrated that the manipulator in principle possesses a fairly regular like workspace with a maximum cuboid defined as the usable workspace inscribed and one isotropic configuration involved. Furthermore, the singularity within the usable workspace is verified, and simulation results show that there exist no any singular configurations within the specified workspace. Therefore, the presented new manipulator has a great potential for high precision industrial applications such as assembly, machining, etc.


Author(s):  
Haotian Cui ◽  
Shuangyue Yu ◽  
Xunge Yan ◽  
Shuo-Hsiu Chang ◽  
Gerard Francisco ◽  
...  

The human hand has extraordinary dexterity with more than 20 degrees of freedom (DOF) actuated by lightweight and efficient biological actuators (i.e., muscles). The average weight of human hand is only 400g [1]. Over the last few decades, research and commercialization effort has been dedicated to the development of novel robotic hands for humanoid or prosthetic application towards dexterous and biomimetic design [2]. However, due to the limitations of existing electric motors in terms of torque density and energy efficiency, the design of humanoid hands has to compromise between dexterity and weight. For example, commercial prosthetic terminal devices i-Limb [3] and Bebionic [4] prioritize the lightweight need (450g) and use 5-DOF motors to under-actuated 11 joints, which is only able to realize a few basic grasp postures. On the other hand, some humanoid robot hand devices like DLR-HIT I & II hands [5] prioritize the dexterity need (15 DOF), but weigh more than four times than their biological counterpart (2200g and 1500g, respectively).


Proceedings ◽  
2018 ◽  
Vol 4 (1) ◽  
pp. 31
Author(s):  
Guillaume Plouffe ◽  
Pierre Payeur ◽  
Ana-Maria Cretu

In this paper, we propose a vision-based recognition approach to control the posture of a robotic arm with three degrees of freedom (DOF) using static and dynamic human hand gestures. Two different methods are investigated to intuitively control a robotic arm posture in real-time using depth data collected by a Kinect sensor. In the first method, the user’s right index fingertip position is mapped to compute the inverse kinematics on the robot. Using the Forward And Backward Reaching Inverse Kinematics (FABRIK) algorithm, the inverse kinematics (IK) solutions are displayed in a graphical interface. Using this interface and his left hand, the user can intuitively browse and select a desired robotic arm posture. In the second method, the user’s left index position and direction are respectively used to determine the end-effector position and an attraction point position. The latter enables the control of the robotic arm posture. The performance of these real-time natural human control approaches is evaluated for precision and speed against static and dynamic obstacles.


Robotica ◽  
2017 ◽  
Vol 35 (12) ◽  
pp. 2381-2399 ◽  
Author(s):  
Lei Cui ◽  
Jie Sun ◽  
Jian S. Dai

SUMMARYRobotic hands use rolling contact to manipulate a grasped object to a desired location, even when the finger and the palm linkage mechanisms lack degrees of freedom. This paper presents a systematic approach to the forward and inverse kinematics of in-hand manipulation. The moving frame method in differential geometry is integrated into the product of exponential formula to establish a pure geometric framework of the kinematics of a robot hand. The forward and inverse kinematics of a multifingered hand are obtained in terms of the joint rates and contact trajectories. A two-fingered planar robot hand and a three-fingered spatial robot hand are used to demonstrate the proposed approach. The proposed formulation amounts to solving a univariate polynomial, providing an alternative to the existing ones that require numerical integration.


2012 ◽  
Vol 187 ◽  
pp. 293-297
Author(s):  
Pramod Kuma Parida ◽  
Bibhuti Bhusan Biswal ◽  
Dhirendra Nath Thatoi

There has been a continuous effort by researchers to develop multi-fingered robot hands for variety of applications. Some of these hands are meant for industrial applications while thers are used for orthopedic rehabilitation of humans. However the degree of success to develop an anthropomorphic robot hand in close resemblence with a typical human hand has not been satisfactory. In the present work an attempt has been made to design a robot hand having five fingers with 25 degrees of freedom by closly following the anatomy of human hand.The kinematic analysis of the hand offers confirmative results for effective graspingand manipulating objects.


Author(s):  
Soo-Chan Jee ◽  
Yu Shin Lee ◽  
Joong Hee Lee ◽  
Sunghwan Park ◽  
Byungki Jin ◽  
...  

Hand tools designed without the anthropometric perspective lead to lower performance and safety. This study suggests a statistical hand shape classification with Korean anthropometric data. A total of 321 anthropometric data were used for this study. To investigate hand types, 27 anthropometric hand variables normalized by the stature of each participant and factor analysis and cluster analysis were conducted. As a result, three major factors were deduced: factors of hand breadth, palm length, and finger length. Additionally, four hand types were determined: (a) a spacious hand with short fingers, (b) a hand with short palm with above average fingers, (c) a long palm and fingers, and (d) a narrow hand and short fingers. In the male population, the spacious hand with short fingers type was dominant while the narrow hand and short fingers type was dominant in the female population. These results are expected to be preliminarily utilized in design for the Korean population.


1998 ◽  
Vol 120 (2) ◽  
pp. 282-292 ◽  
Author(s):  
Li-Ren Lin ◽  
Han-Pang Huang

A new five-finger robot hand (NTU hand) with seventeen degrees of freedom (DOF) is developed in this paper. In contrast to traditional tendon-driven robots, the NTU hand has an uncoupled configuration that each finger and joint are all individually driven. Since all actuators, mechanical parts and sensors are packed on the hand, the size of NTU hand is almost the same as a human hand. Such compact design makes the hand easily adapt to the industrial robot arm and the prosthetic applications. Based on the mechanical structure of the NTU hand, the direct and inverse kinematics are developed. In addition, computer simulation with three-dimension graphics is built to evaluate the manipulable range of the NTU hand. From the simulation, the relationship between the hand and the grasped object in a specific point of view can be obtained.


2014 ◽  
Vol 611 ◽  
pp. 75-82 ◽  
Author(s):  
Ivan Virgala ◽  
Alexander Gmiterko ◽  
Michal Kelemen ◽  
Ľubica Miková ◽  
Martin Varga

Our study deals with inverse kinematic model of humanoid robot hand. It is important for modeling to know biomechanics of biological human hand, what is discussed in the second section. Based on theoretical aspect of kinematic configuration of the hand, the hand consisting of 24 degrees of freedom is assumed. Subsequently, there are four numerical methods of inverse kinematics used, namely pseudoinverse method, Jacobian transpose method, damped least squares and optimization method. Each of them is simulated in software Matlab and the results are compared and discussed. In the conclusion the best method from the view of solution time and number of iteration cycles is evaluated.


2020 ◽  
Vol 27 (5) ◽  
pp. 400-410
Author(s):  
Valentina De Luca ◽  
Luigi Mandrich

: Enzymes are among the most studied biological molecules because better understanding enzymes structure and activity will shed more light on their biological processes and regulation; from a biotechnological point of view there are many examples of enzymes used with the aim to obtain new products and/or to make industrial processes less invasive towards the environment. Enzymes are known for their high specificity in the recognition of a substrate but considering the particular features of an increasing number of enzymes this is not completely true, in fact, many enzymes are active on different substrates: this ability is called enzyme promiscuity. Usually, promiscuous activities have significantly lower kinetic parameters than to that of primary activity, but they have a crucial role in gene evolution. It is accepted that gene duplication followed by sequence divergence is considered a key evolutionary mechanism to generate new enzyme functions. In this way, promiscuous activities are the starting point to increase a secondary activity in the main activity and then get a new enzyme. The primary activity can be lost or reduced to a promiscuous activity. In this review we describe the differences between substrate and enzyme promiscuity, and its rule in gene evolution. From a practical point of view the knowledge of promiscuity can facilitate the in vitro progress of proteins engineering, both for biomedical and industrial applications. In particular, we report cases regarding esterases, phosphotriesterases and cytochrome P450.


Robotica ◽  
2021 ◽  
pp. 1-12
Author(s):  
Paolo Di Lillo ◽  
Gianluca Antonelli ◽  
Ciro Natale

SUMMARY Control algorithms of many Degrees-of-Freedom (DOFs) systems based on Inverse Kinematics (IK) or Inverse Dynamics (ID) approaches are two well-known topics of research in robotics. The large number of DOFs allows the design of many concurrent tasks arranged in priorities, that can be solved either at kinematic or dynamic level. This paper investigates the effects of modeling errors in operational space control algorithms with respect to uncertainties affecting knowledge of the dynamic parameters. The effects on the null-space projections and the sources of steady-state errors are investigated. Numerical simulations with on-purpose injected errors are used to validate the thoughts.


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