Dexterous Gripper Synthesis From Modular Finger Approach

2017 ◽  
Author(s):  
Nahian Rahman ◽  
Carlo Canali ◽  
Darwin G. Caldwell ◽  
Ferdinando Cannella
Keyword(s):  
Mathematical Formulation ◽  
Degree Of Freedom ◽  
Human Hand ◽  
Soft Or ◽  
Rigid Material ◽  
Human Hands

Dexterous gripper requirements, such as in-hand manipulation is a capability on which human hands are unique at; numerous number of sensors, degree of freedom, adaptability to deal with plurality of object of our hand motivate the researchers to replicate these abilities in robotic grippers. Developments of gripper or grasping devices have been addressed from many perspectives: the use of materials in the gripper synthesis, such as rigid or flexible, the approach of control, use of under-actuated mechanism and so on. Mathematical formulation of grasp modeling, manipulation are also addressed; however, due to the presence non-holonomic motion, it is difficult to replicate the behaviors (achieved in model) in a physical gripper. Also, achieving skills similar to human hand urge to use soft or non rigid material in the gripper design, which is contrary to speed and precision requirements in an industrial gripper. In this dilemma, this paper addresses the problem by developing modular finger approach. The modular finger is built by two well known mechanisms, and exploiting such modular finger in different numbers in a gripper arrangement can solve many rising issues of manipulation.

Nonlinear Normal Modes and Localization in Elastic Vibro-Impact Systems With Multiple Constraints

2007 ◽  
Author(s):  
David Wagg
Keyword(s):  
Mathematical Formulation ◽  
Normal Modes ◽  
Nonlinear Normal Modes ◽  
Degree Of Freedom ◽  
Lumped Mass ◽  
Localized Modes ◽  
Impact Oscillator ◽  
Mass System ◽  
Nonlinear Normal ◽  
Two Degree Of Freedom

In this paper we consider the dynamics of compliant mechanical systems subject to combined vibration and impact forcing. Two specific systems are considered; a two degree of freedom impact oscillator and a clamped-clamped beam. Both systems are subject to multiple motion limiting constraints. A mathematical formulation for modelling such systems is developed using a modal approach including a modal form of the coefficient of restitution rule. The possible impact configurations for an N degree of freedom lumped mass system are considered. We then consider sticking motions which occur when a single mass in the system becomes stuck to an impact stop, which is a form of periodic localization. Then using the example of a two degree of freedom system with two constraints we describe exact modal solutions for the free flight and sticking motions which occur in this system. A numerical example of a sticking orbit for this system is shown and we discuss identifying a nonlinear normal modal basis for the system. This is achieved by extending the normal modal basis to include localized modes. Finally preliminary experimental results from a clamped-clamped vibroimpacting beam are considered and a simplified model discussed which uses an extended modal basis including localized modes.

Analysis of Hand-Arm Coordinate Motion on Constraint Tasks

1991 ◽  
Vol 3 (6) ◽  
pp. 497-505
Author(s):  
Shigeki Sugano ◽  
◽  
Hideyo Namimoto ◽  
Ichiro Kato
Keyword(s):  
Control Strategy ◽  
Force Control ◽  
Degrees Of Freedom ◽  
Control Mechanism ◽  
Human Motion ◽  
Degree Of Freedom ◽  
Human Hand ◽  
Human Motion Analysis ◽  
Manipulator Control ◽  
Arm Coordination

This research was conducted to study the control strategy of manipulator based on clarifying the force control mechanism of the human hand-arm by analyzing human constraint tasks with respect to biomechanism. In this paper; we describe an investigation of hand-arm function share. In addition, we apply hand-arm coordination to manipulator control using experimental results of analyzing the human tasks of moving bead balls on a shaft, which is an example of a constraint task with one degree of freedom (d.o.f.). In the human motion analysis, 6 axes of force on the task object are measured and compared in the case of constraining the hands degree of freedom and making hand free as well as in the case of with or without forced displacement along the translational direction during motion. As a result, we found that human work was performed smoothly through absorption of rotational force using hand d.o.f. and translational force using arm d.o.f. Also, it was found that there are the direction of motion and the posture easily absorbable translational force. Finally, we propose to apply the human hand-arm coordination compliance control strategy setting translational compliance by arms and rotational compliance by hands, to manipulator with more than 7 degrees of freedom. Thus, the setting of optional compliance applicable to circumstance and the resulting force control due to this become possible.

scholarly journals Pressure distribution classification and segmentation of human hands in contact with the robot body

2020 ◽  
Vol 39 (6) ◽  
pp. 668-687
Author(s):  
Alessandro Albini ◽  
Giorgio Cannata
Keyword(s):  
Pressure Distribution ◽  
Linear Manifold ◽  
Two Dimensions ◽  
Human Robot Interaction ◽  
Geometric Transformation ◽  
Human Hand ◽  
Physical Interaction ◽  
Underlying Assumption ◽  
Robot Body ◽  
Human Hands

This article deals with the problem of the recognition of human hand touch by a robot equipped with large area tactile sensors covering its body. This problem is relevant in the domain of physical human–robot interaction for discriminating between human and non-human contacts and to trigger and to drive cooperative tasks or robot motions, or to ensure a safe interaction. The underlying assumption used in this article is that voluntary physical interaction tasks involve hand touch over the robot body, and therefore the capability to recognize hand contacts is a key element to discriminate a purposive human touch from other types of interaction. The proposed approach is based on a geometric transformation of the tactile data, formed by pressure measurements associated to a non-uniform cloud of 3D points ( taxels) spread over a non-linear manifold corresponding to the robot body, into tactile images representing the contact pressure distribution in two dimensions. Tactile images can be processed using deep learning algorithms to recognize human hands and to compute the pressure distribution applied by the various hand segments: palm and single fingers. Experimental results, performed on a real robot covered with robot skin, show the effectiveness of the proposed methodology. Moreover, to evaluate its robustness, various types of failures have been simulated. A further analysis concerning the transferability of the system has been performed, considering contacts occurring on a different sensorized robot part.

Design and Performance of a Motor-Driven Mechanism to Conduct Experiments With the Human Index Finger

2015 ◽  
Vol 7 (3) ◽  
Author(s):  
Pei-Hsin Kuo ◽  
Jerod Hayes ◽  
Ashish D. Deshpande
Keyword(s):  
Index Finger ◽  
Human Subjects ◽  
Joint Stiffness ◽  
Viscoelastic Behavior ◽  
Neuromuscular Control ◽  
External Loading ◽  
Human Hand ◽  
Robotic Hands ◽  
Hand Biomechanics ◽  
Human Hands

Passive properties of the human hands, defined by the joint stiffness and damping, play an important role in hand biomechanics and neuromuscular control. Introduction of mechanical element that generates humanlike passive properties in a robotic form may lead to improved grasping and manipulation abilities of the next generation of robotic hands. This paper presents a novel mechanism, which is designed to conduct experiments with the human subjects in order to develop mathematical models of the passive properties at the metacarpophalangeal (MCP) joint. We designed a motor-driven system that integrates with a noninvasive and infrared motion capture system, and can control and record the MCP joint angle, angular velocity, and passive forces of the MCP joint in the index finger. A total of 19 subjects participated in the experiments. The modular and adjustable design was suitable for variant sizes of the human hands. Sample results of the viscoelastic moment, hysteresis loop, and complex module are presented in the paper. We also carried out an error analysis and a statistical test to validate the reliability and repeatability of the mechanism. The results show that the mechanism can precisely collect kinematic and kinetic data during static and dynamic tests, thus allowing us to further understand the insights of passive properties of the human hand joints. The viscoelastic behavior of the MCP joint showed a nonlinear dependency on the frequency. It implies that the elastic and viscous component of the hand joint coordinate to adapt to the external loading based on the applied frequency. The findings derived from the experiments with the mechanism can provide important guidelines for design of humanlike compliance of the robotic hands.

Transforming Human Hand Motion for Telemanipulation

1992 ◽  
Vol 1 (1) ◽  
pp. 63-79 ◽  
Author(s):  
Thomas H. Speeter
Keyword(s):  
Force Feedback ◽  
Robotic Manipulation ◽  
Human Hand ◽  
Robotic Hand ◽  
Robotic Hands ◽  
Automated Control ◽  
Functional Transformation ◽  
Hand Motion ◽  
Computationally Expensive ◽  
Human Hands

Manipulation by teleoperation (telemanipulation) offers an apparently straightforward and less computationally expensive route toward dextrous robotic manipulation than automated control of multifingered robotic hands. The functional transformation of human hand motions into equivalent robotic hand motions, however, presents both conceptual and analytical problems. This paper reviews and proposes algorithmic methods for transforming the actions of human hands into equivalent actions of slave multifingered robotic hands. Forward positional transformation is considered only, the design of master devices, feedforward dynamics, and force feedback are not considered although their importance for successful telemanipulation is understood. Linear, nonlinear, and functional mappings are discussed along with performance and computational considerations.

Discriminability and Identifiability of the Human Hand Based on its Quantified Complexity

1976 ◽  
Vol 42 (1) ◽  
pp. 287-293 ◽  
Author(s):  
William A. Seman ◽  
Robert Pasnak ◽  
Zita E. Tyer
Keyword(s):  
Human Hand ◽  
Parametric Investigation ◽  
Made In ◽  
Human Hands

Photographs of human hands were quantified according to a method suggested by Attneave (1954). The over-all complexity of the hands' contours did not affect the accuracy with which pairs and non-pairs of hands could be discriminated. However, significantly more errors were made in identifying the mates of hands whose thumb regions were relatively complex. These results suggest that the contours of nonlaboratory forms are quantifiable and amenable to parametric investigation.

scholarly journals On the Structural Synthesis of Multi-Fingered Hands

2000 ◽  
Author(s):  
Jyh-Jone Lee ◽  
Chun-Po Chen
Keyword(s):  
Contact Geometry ◽  
Human Hand ◽  
Robot Arm ◽  
Structural Synthesis ◽  
End Effector ◽  
New Approach ◽  
Mechanical Hand ◽  
Autonomous Manipulation ◽  
Force Closure ◽  
Human Hands

Abstract Compared to the serial type of six-freedom robot arm attached with an end-effector, the multi-fingered hand system can provide more dexterity and versatility in the field of autonomous manipulation tasks. Designs of multi-fingered hands can be found in the literature, to name a few, Mechanical Hand by Skinner [13], Multi-jointed Finger System by Okada [6], Stanford/JPL Hand (or Salisbury Hand) [11], Utah-MIT Hand [3], and NTU-1 Hand [5]. Generally, these mechanical hand systems have been designed to simulate a subset function of human hands. The structures of these systems basically resemble the skeleton of human hand and are constructed by designers’ intuition. Not much literature addressed about the structural synthesis of multi-fingered hands. This paper presents a new approach for the structural synthesis of multi-fingered hands. It takes into account both the total mobility and the force closure criterion of the system. Based upon the Grübler’s mobility equation, relations regarding the numbers of fingers, contact geometry, and object freedoms are established. Subsequently, by applying the force closure criterion, the total number of possible multi-fingered hands with given mobility are synthesized.

Analysis and Systematic Classification of Human Hand Movement for Robot Hand Design

2008 ◽  
Vol 20 (3) ◽  
pp. 429-435 ◽  
Author(s):  
Takeshi Ninomiya ◽  
◽  
Takashi Maeno ◽  
Keyword(s):  
Hand Movement ◽  
Hand Movements ◽  
Human Hand ◽  
Robot Hand ◽  
Systematic Classification ◽  
Robot Hands ◽  
Human Muscles ◽  
Set Up ◽  
Human Hands

The systematic classification of hand movements, which indicates the minimum mechanism of robot hands, is suggested. The performance of existent robot hands is not as high as that of human hands because the performance of existent actuators does not come up to that of human muscles in the same volume. It is important for robot hands to accomplish targeted tasks with a minimum mechanism. Human hand movements are analyzed quantitatively considering robot hands such as associated movement of DIP and PIP joints. Based on the results of analysis, we obtain three items, i.e., fingers, joints that must be set up actuators and basic movements we define. We systematically classify human hand movement for the robot hand based on three items.

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