scholarly journals VGS Hand: A Novel Hybrid Grasping Modes Robot Hand with Variable Geometrical Structure

2019 ◽  
Vol 9 (8) ◽  
pp. 1566 ◽  
Author(s):  
Luo ◽  
Zhang
Keyword(s):  
Flat Surface ◽  
Geometrical Structure ◽  
Contact Forces ◽  
Degree Of Freedom ◽  
Robot Hand ◽  
Straight Line ◽  
Robot Hands ◽  
Potential Applications ◽  
Application Requirements ◽  
Self Adaptive

Robot hand is the device used for robots to interact with the environments, it has many potential applications. Traditional robot hands cannot translate their finger end along a straight line, which makes them not suitable for grasping thin objects on a flat surface. In order to overcome the bottleneck of traditional hands and enlarge the application possibility of robot hands, this paper develops a novel hybrid grasping modes hand with the variable geometrical structure (called VGS hand). The hand consists of 4-DOF (degree of freedom), two actuators and two fingers. It can perform both linear-parallel and self-adaptive grasping modes. Kinematics, dynamics, and contact forces analysis are conducted to provide a theoretical reference for the design. A prototype was manufactured for grasping experiments; the results of the experiments indicate that the hand has a good grasping performance and can meet different application requirements.

scholarly journals Pinching at Fingertips for Humanoid Robot Hand

2005 ◽  
Vol 17 (6) ◽  
pp. 655-663 ◽  
Author(s):  
Kiyoshi Hoshino ◽  
◽  
Ichiro Kawabuchi ◽  
Keyword(s):  
Force Control ◽  
Degrees Of Freedom ◽  
Humanoid Robot ◽  
Degree Of Freedom ◽  
Robot Hand ◽  
Motor Functions ◽  
Weak Force ◽  
Robot Hands ◽  
Finger Motion

Delicate actions such as picking up paper or a needle with the fingertips – an important function for robot hands – are extremely difficult. We propose a lightweight robot hand based on extracting minimum required motor functions and implementing them in a robot. We also propose a robot hand that realizes appropriate pinching by adding the minimum required degree of supplementary freedom realizable only mechanically. In the robot hand, we focus mainly on adding degrees of freedom for independent finger motion to the terminal joints and a degree of freedom for twisting by the thumb. The results showed that providing the fingertip with a joint with broad force control even with weak force effectively ensures delicate fingertip control in a humanoid robot hand.

TWO-DOF COUPLED AND SELF-ADAPTIVE (COSA) FINGER: A NOVEL UNDER-ACTUATED MECHANISM

2013 ◽  
Vol 10 (02) ◽  
pp. 1330001 ◽  
Author(s):  
WENZENG ZHANG ◽  
DEYANG ZHAO ◽  
HAIPENG ZHOU ◽  
ZHENGUO SUN ◽  
DONG DU ◽  
...  
Keyword(s):  
Theoretical Analysis ◽  
Degree Of Freedom ◽  
Robot Hands ◽  
Self Adaptation ◽  
Self Adaptive

A large amount of effort has been devoted to design better under-actuated robot hands. The most widely adopted approaches include rigid coupled hands and self-adaptive hands. The objective of this research is to design a robot finger which combines advantages of both ways and overcomes their disadvantages. The concept of coupling and self-adaptation (COSA) was introduced. A linkage-based two-DOF (degree of freedom) COSA robot finger was designed, optimized and studied in this paper. The theoretical analysis and the experiments on the finger show that it is able to execute human-like motion and adaptive grasps in multiple patterns. The research exposes a promising novel under-actuated mechanism for hands design with wide applications.

Vehicle State Estimation Using Dynamic 7 Degree-of-Freedom Observer

2006 ◽  
Author(s):  
Valery N. Pylypchuk ◽  
Nikolai K. Moshchuk ◽  
Shih-Ken Chen
Keyword(s):  
Frequency Response ◽  
State Estimation ◽  
Vehicle Dynamics ◽  
Flat Surface ◽  
Observer Design ◽  
Degree Of Freedom ◽  
Vehicle Body ◽  
Straight Line ◽  
Vehicle State Estimation ◽  
Vehicle Testing

This paper presents a dynamic Luenberger's observer design with wheel dynamics as an essential component. 7DOF model of the vertical vehicle dynamics is modified for the case of independent-solid axle suspension and applied to predicting the vehicle body and wheel states. The observer greatly reduces the effect of uncertainty even with unknown road inputs. The design is verified through Carsim simulation and vehicle testing under variety of maneuvers including Fishhook and frequency response on a flat surface, straight line driving on a rough road, and on a cross-slope roads.

Topological Structural Design of Umbrella-Shaped Deployable Mechanisms Based on New Spatial Closed-Loop Linkage Units

2018 ◽  
Vol 140 (6) ◽  
Author(s):  
Wen-ao Cao ◽  
Donghao Yang ◽  
Huafeng Ding
Keyword(s):  
Structural Design ◽  
Closed Loop ◽  
Space Exploration ◽  
Degree Of Freedom ◽  
Structural Symmetry ◽  
Potential Applications ◽  
Good Potential

The umbrella linkage is one of the most classical deployable mechanisms. This paper concentrates on topological structural design of a family of umbrella-shaped deployable mechanisms based on new two-layer and two-loop spatial linkage units. First, deployable units are developed systematically from two-layer and two-loop linkage with four revolute pair (4R) coupling chains. Then, mobile connection modes of the deployable units are established based on the conditions of one degree-of-freedom (DOF) and structural symmetry. Finally, umbrella-shaped deployable mechanisms are constructed based on the developed deployable units and the established mobile connection modes. Like umbrellas, the designed deployable mechanisms can be actuated in a simple and reliable way, and those mechanisms have good potential applications in the fields of architecture, manufacturing, space exploration, and recreation.

Force Capabilities of Two-Degree-of-Freedom Serial Robots Equipped With Passive Isotropic Force Limiters

2015 ◽  
Author(s):  
Meiying Zhang ◽  
Thierry Laliberté ◽  
Clément Gosselin
Keyword(s):  
Human Robot Interaction ◽  
Contact Forces ◽  
Degree Of Freedom ◽  
Practical Implementation ◽  
Robot Interaction ◽  
End Effector ◽  
Serial Robots ◽  
Serial Robot ◽  
Maximum Contact ◽  
Two Degree Of Freedom

This paper proposes the use of passive force and torque limiting devices to bound the maximum forces that can be applied at the end-effector or along the links of a robot, thereby ensuring the safety of human-robot interaction. Planar isotropic force limiting modules are proposed and used to analyze the force capabilities of a two-degree-of-freedom planar serial robot. The force capabilities at the end-effector are first analyzed. It is shown that, using isotropic force limiting modules, the performance to safety index remains excellent for all configurations of the robot. The maximum contact forces along the links of the robot are then analyzed. Force and torque limiters are distributed along the structure of the robot in order to ensure that the forces applied at any point of contact along the links are bounded. A power analysis is then presented in order to support the results. Finally, examples of mechanical designs of force/torque limiters are shown to illustrate a possible practical implementation of the concept.

A 3-DOF Friction-Free Planar Motor Using Piezoelectric Elements

2012 ◽  
Vol 523-524 ◽  
pp. 739-744 ◽  
Author(s):  
Akihiro Torii ◽  
Mitsuhiro Nishio ◽  
Yuki Itatsu ◽  
Kae Doki ◽  
Akiteru Ueda
Keyword(s):  
Flat Surface ◽  
Thrust Force ◽  
Levitation Force ◽  
Vertical Vibration ◽  
Degree Of Freedom ◽  
Horizontal Direction ◽  
Horizontal Deformation ◽  
Piezoelectric Elements ◽  
Three Degree Of Freedom

A friction-free planar motor, which is composed of piezoelectric elements (piezos), is proposed. The motor is based on the principle of an inchworm using levitation mechanisms. The vertical vibration of the piezo generates the levitation force of the motor. The horizontal deformation of the piezo causes the thrust force of the motor. These piezos realizes three degree-of-freedom motion on a flat surface. We measure the displacement in the vertical and horizontal direction of the levitation mechanism. The feasibility of the inchworm using levitation mechanisms is described.

scholarly journals Productivity Evaluation of Self-Adaptive Software Model Driven Architecture

2014 ◽  
pp. 191-210
Author(s):  
Basel Magableh ◽  
Stephen Barrett
Keyword(s):  
Dynamic Decision Making ◽  
Development Effort ◽  
Model Driven Architecture ◽  
Model Driven ◽  
Software Model ◽  
Source Line ◽  
Formal Procedure ◽  
Context Dependent ◽  
Application Requirements ◽  
Self Adaptive

Anticipating context changes using a model-based approach requires a formal procedure for analysing and modelling context-dependent functionality and stable description of the architecture which supports dynamic decision-making and architecture evolution. This article demonstrates the capabilities of the context-oriented component-based application model-driven architecture (COCA-MDA) to support the development of self-adaptive applications; the authors describe a state-of-the-art case study and evaluate the development effort involved in adopting the COCA-MDA in constructing the application. An intensive analysis of the application requirements simplified the process of modelling the application’s behavioural model; therefore, instead of modelling several variation models, the developers modelled an extra-functionality model. COCA-MDA reduces the development effort because it maintains a clear separation of concerns and employs a decomposition mechanism to produce a context-oriented component model which decouples the applications’ core functionality from the context-dependent functionality. Estimating the MDA approach’s productivity can help the software developers select the best MDA-based methodology from the available solutions. Thus, counting the source line of code is not adequate for evaluating the development effort of the MDA-based methodology. Quantifying the maintenance adjustment factor of the new, adapted, and reused code is a better estimate of the development effort of the MDA approaches.

Calculation of Contact Forces of Large-Scale Heavy Forging Manipulator Grippers

2009 ◽  
Vol 419-420 ◽  
pp. 645-648 ◽  
Author(s):  
Qun Ming Li ◽  
Dan Gao ◽  
Hua Deng
Keyword(s):  
Large Scale ◽  
Optimization Method ◽  
Contact Forces ◽  
Robotic Hand ◽  
Closure Condition ◽  
Contact Points ◽  
Robot Hands ◽  
Calculation Results ◽  
Forging Manipulator ◽  
Gripping Force

Different from dexterous robotic hands, the gripper of heavy forging manipulator is an underconstrained mechanism whose tongs are free in a small wiggling range. However, for both a dexterous robotic hand and a heavy gripper, the force closure condition: the force and the torque equilibrium, must be satisfied without exception to maintain the grasping/gripping stability. This paper presents a gripping model for the heavy forging gripper with equivalent friction points, which is similar to a grasp model of multifingered robot hands including four contact points. A gripping force optimization method is proposed for the calculation of contact forces between gripper tongs and forged object. The comparison between the calculation results and the experimental results demonstrates the effectiveness of the proposed calculation method.

Object Oriented Dexterity Analysis and Design Application for Spatial Robot Hands

1989 ◽  
Author(s):  
L. Lu ◽  
C. Cai ◽  
A. H. Soni
Keyword(s):  
Performance Evaluation ◽  
Object Oriented ◽  
Kinematic Parameter ◽  
Least Square ◽  
Parameter Determination ◽  
Robot Hand ◽  
Kinematic Parameters ◽  
Analysis And Design ◽  
Robot Hands

Abstract For an arbitrarily shaped object manipulated by a robot hand, this paper presents a procedure for analyzing the position and rotation ranges of the object, and a procedure for designing the kinematic parameters of a hand to meet given requirements on the motion ranges. Rotation dexterity index, dexterity charts, and a dexterity scalar characterizing both position range and rotation range are introduced for the performance evaluation of a robot hand. Least-square-error iteration and steps are detailed for the kinematic parameter determination of a robot hand.

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