Manipulability of Closed Kinematic Chains

1998 ◽  
Vol 120 (4) ◽  
pp. 542-548 ◽  
Author(s):  
F. C. Park ◽  
J. W. Kim
Keyword(s):  
Dynamic Characteristics ◽  
Geometric Analysis ◽  
Riemannian Metric ◽  
Kinematic Chains ◽  
Closed Chain ◽  
Invariant Differential ◽  
Practical Algorithm ◽  
Uniform Manner

This paper presents a coordinate-invariant differential geometric analysis of manipulability for closed kinematic chains containing active and passive joints. The formulation treats both redundant and nonredundant mechanisms, as well as over-actuated and exactly actuated ones, in a uniform manner. Dynamic characteristics of the mechanism and manipulated object can also be naturally included by an appropriate choice of Riemannian metric. We illustrate the methodology with several closed chain examples, and provide a practical algorithm for manipulability analysis of general chains.

Singularity Analysis of Closed Kinematic Chains

1999 ◽  
Vol 121 (1) ◽  
pp. 32-38 ◽  
Author(s):  
F. C. Park ◽  
J. W. Kim
Keyword(s):  
Configuration Space ◽  
Degrees Of Freedom ◽  
Geometric Analysis ◽  
Singularity Analysis ◽  
Geometric Framework ◽  
End Effector ◽  
Kinematic Chains ◽  
Closed Chain ◽  
High Level ◽  
Kinematic Singularities

This paper presents a coordinate-invariant differential geometric analysis of kinematic singularities for closed kinematic chains containing both active and passive joints. Using the geometric framework developed in Park and Kim (1996) for closed chain manipulability analysis, we classify closed chain singularities into three basic types: (i) those corresponding to singular points of the joint configuration space (configuration space singularities), (ii) those induced by the choice of actuated joints (actuator singularities), and (iii) those configurations in which the end-effector loses one or more degrees of freedom of available motion (end-effector singularities). The proposed geometric classification provides a high-level taxonomy for mechanism singularities that is independent of the choice of local coordinates used to describe the kinematics, and includes mechanisms that have more actuators than kinematic degrees of freedom.

A Comparative Approach Regarding the Dynamic Behaviour of Planetary Transmissions Used in Industrial Robots

2016 ◽  
Vol 834 ◽  
pp. 120-125
Author(s):  
Paul Alin Butunoi ◽  
Gheorghe Stan ◽  
Catalina Ciofu ◽  
Ana Lacramioara Ungureanu
Keyword(s):  
Dynamic Characteristics ◽  
Significant Influence ◽  
Dynamic Behaviour ◽  
Response Times ◽  
Industrial Robots ◽  
Comparative Approach ◽  
Direct Influence ◽  
Positioning Accuracy ◽  
Torque Distribution ◽  
Kinematic Chains

The dynamic characteristics of planetary transmissions have a direct influence over the possibilities of industrial robots regarding the imposed trajectory. Also, the conditions specific to the achievement of the transient regime have a significant influence over the positioning accuracy of the robots. In this paper, a comparative approach is proposed, applied to four types of planetary transmissions, concerning the gyration torque distribution and computation. Based on the computation equations presented in this paper, some optimization strategies concerning the response times of the overall kinematic chains are proposed.

Liquid crystalline ordering of paired helical filaments in neurofibrillary tangles of Alzheimer's disease

1986 ◽  
Vol 44 ◽  
pp. 348-349
Author(s):  
D.F. Clapin ◽  
V.J.A. Montpetit
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Neurofibrillary Tangles ◽  
Liquid Crystalline ◽  
Amyloid Fibrils ◽  
Geometric Analysis ◽  
Paired Helical Filaments ◽  
Microscopic Level ◽  
Light Microscopic Level ◽  
Regular Spacing

Alzheimer's disease is characterized by the accumulation of abnormal filamentous proteins. The most important of these are amyloid fibrils and paired helical filaments (PHF). PHF are located intraneuronally forming bundles called neurofibrillary tangles. The designation of these structures as "tangles" is appropriate at the light microscopic level. However, localized domains within individual tangles appear to demonstrate a regular spacing which may indicate a liquid crystalline phase. The purpose of this paper is to present a statistical geometric analysis of PHF packing.

Geometric analysis

1976 ◽  
Vol 55 (2) ◽  
pp. 67
Author(s):  
C.A. Gladman ◽  
R.A. Williams
Keyword(s):  
Geometric Analysis

Invited PaperTemperature dependence of SiGe HBT static and dynamic characteristics

1998 ◽  
Vol 08 (PR3) ◽  
pp. Pr3-81-Pr3-86
Author(s):  
F. Aniel ◽  
N. Zerounian ◽  
A. Gruhle ◽  
C. Mähner ◽  
G. Vernet ◽  
...  
Keyword(s):  
Dynamic Characteristics ◽  
Static And Dynamic Characteristics ◽  
Sige Hbt
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