Kinematics of Planar Multifingered Robot Hand with Displacement of Contact Points.

1991 ◽  
Vol 57 (540) ◽  
pp. 2667-2674
Author(s):  
Nobuharu MIMURA ◽  
Yasuyuki FUNAHASHI
Keyword(s):  
Robot Hand ◽  
Contact Points

An Algorithm for Force-Closure Grasping of Three-Fingered Hand

2011 ◽  
Vol 250-253 ◽  
pp. 3965-3970
Author(s):  
Qing Yun Liu ◽  
Bo Jiang ◽  
Xiao Liu Yu
Keyword(s):  
Full Rank ◽  
Existence Condition ◽  
Robot Hand ◽  
Relative Location ◽  
Equilibrium Relation ◽  
Geometrical Characteristics ◽  
Contact Points ◽  
Force Closure ◽  
Internal Forces ◽  
Hand Force

On the assumption of FCWF model, the conditions of three-fingered robot hand force-closure grasping are equivalent to grasp matrix be full rank and exist rigorous internal forces. Based on the analysis to the geometrical characteristics of contact points, the existence condition of the frictional sectors is established. By means of studying the relative location relationships between the frictional sector borderlines and their intersections, the existence condition of the concurrent polygon of three internal forces is presented. Taking the equilibrium relation of internal forces into consideration, a general algorithm using vector calculation for force-closure grasping is established. An example is given to illustrate the validity of the algorithm.

Parameter Identification of a Grasp by a Planar Two-Fingered Robot Hand

1993 ◽  
Vol 5 (1) ◽  
pp. 12-18 ◽  
Author(s):  
Nobuharu Mimura ◽  
◽  
Yasuyuki Funahashi ◽  
Keyword(s):  
Parameter Identification ◽  
Robot Hand ◽  
Joint Angles ◽  
Unknown Parameters ◽  
Numerical Example ◽  
Contact Points ◽  
Unknown Object

Unknown forced and unknown contact points for the case in which a planar two-fingered robot hand achieves a stable grasp on an unknown object are identified in this paper. It is shown that the unknown parameters of the grasping system can be identified by detection of joint angles and torques while the object is manipulated slightly. Finally, it is illustrated by a numerical example that the algorithm of the grasp parameter identification is valid.

A Shape Description Model by Using Sensor Data From Touch

2003 ◽  
Author(s):  
Venturia Chiroiu ◽  
Ligia Munteanu ◽  
Cornel Mihai Nicolescu
Keyword(s):  
Sensor Data ◽  
Tactile Sensing ◽  
Shape Description ◽  
Robot Hand ◽  
3D Object ◽  
Contact Points ◽  
Data Points ◽  
Dexterous Robot Hand

In this paper we consider the problem of recognizing the shape of a 3D object using tactile sensing by a dexterous robot hand. Our approach uses multiple fingers to slide along the surface of the object. From the sensing contact points we extracts a number of 3D points belonging to the surface of the object. The unknown surface Γ of the object is determined by using an “n-ellipsoid” model (Bonnet [1]). The set of parameters that define the surface Γ is determined such that the n-ellipsoid best fits the set of data points.

Effects of occlusal scheme on All-on-Four abutments, screws and prostheses: A three-dimensional finite element study

2020 ◽  
Author(s):  
Nurullah Türker ◽  
Hümeyra Tercanlı Alkış ◽  
Steven J Sadowsky ◽  
Ulviye Şebnem Büyükkaplan
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Good Prognosis ◽  
Von Mises Stress ◽  
Element Analysis ◽  
Group Function ◽  
Occlusal Contact ◽  
Maximum Deformation ◽  
Contact Points ◽  
Von Mises

An ideal occlusal scheme plays an important role in a good prognosis of All-on-Four applications, as it does for other implant therapies, due to the potential impact of occlusal loads on implant prosthetic components. The aim of the present three-dimensional (3D) finite element analysis (FEA) study was to investigate the stresses on abutments, screws and prostheses that are generated by occlusal loads via different occlusal schemes in the All-on-Four concept. Three-dimensional models of the maxilla, mandible, implants, implant substructures and prostheses were designed according to the All-on-Four concept. Forces were applied from the occlusal contact points formed in maximum intercuspation and eccentric movements in canine guidance occlusion (CGO), group function occlusion (GFO) and lingualized occlusion (LO). The von Mises stress values for abutment and screws and deformation values for prostheses were obtained and results were evaluated comparatively. It was observed that the stresses on screws and abutments were more evenly distributed in GFO. Maximum deformation values for prosthesis were observed in the CFO model for lateral movement both in the maxilla and mandible. Within the limits of the present study, GFO may be suggested to reduce stresses on screws, abutments and prostheses in the All-on-Four concept.

Sign in / Sign up

Export Citation Format

Share Document