Elastodynamics of a two-limb Schönflies motion generator

2014 ◽  
Vol 229 (4) ◽  
pp. 751-764 ◽  
Author(s):  
Afshin Taghvaeipour ◽  
Jorge Angeles ◽  
Larry Lessard
Keyword(s):  
Natural Frequencies ◽  
Mass Matrix ◽  
Point Of View ◽  
Mass Matrices ◽  
The Subject ◽  
Robot Performance ◽  
Schönflies Motion ◽  
The Given ◽  
Pick And Place Operation ◽  
Motion Generator

The elastodynamic analysis of a two-limb Schönflies motion generators is the subject of this paper. This analysis calls for the calculation of the stiffness and mass matrices. By resorting to the generalized spring concept, the posture-dependent stiffness matrix of the robot is computed. With the motors locked, the motion caused by the flexible components leads to the robot mass matrix. The generalized springs help to simplify the model. Although this simplification filters out the higher natural frequencies, it eases the computation of the posture-dependent stiffness and mass matrices. This provides a valuable tool to simplify the evaluation of the robot performance from an elastodynamic point of view, while the robot executes a given task. Finally, the modal analysis of the McGill Schönflies motion generator, while executing a pick-and-place operation, is conducted; under these conditions, the evolution of the first six natural frequencies is obtained. The elastodynamic performance of the robot for the given task is assessed using the results of the analysis.

scholarly journals Elastodynamics of a parallel Schönflies-motion generator

2020 ◽  
Vol 44 (4) ◽  
pp. 511-519
Author(s):  
Zuyu Yin ◽  
Bruno Belzile ◽  
Jorge Angeles ◽  
James Richard Forbes
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Natural Frequencies ◽  
The Finite Element Method ◽  
Test Cycle ◽  
Operation Speed ◽  
Mass Matrices ◽  
Pick And Place ◽  
Schönflies Motion ◽  
Motion Generator

The authors propose a model of the elastodynamics of the Peppermill Carrier, a parallel isostatic Schönflies-motion generator designed for pick-and-place operations. The Cartesian spring and the finite element method are used to build the elastodynamics model of the robot. The stiffness and mass matrices are introduced to obtain the natural frequencies of the robot along a test trajectory — the Adept test cycle — that serves to evaluate the performance of the robot with respect to the operation speed.

scholarly journals Scientific methods of public administration in migration research

2020 ◽  
Vol 68 (2) ◽  
pp. 109-122
Author(s):  
András László Szabó
Keyword(s):  
Public Administration ◽  
Research Methods ◽  
Methodological Approach ◽  
Point Of View ◽  
Scientific Methods ◽  
Migration Research ◽  
Independent Field ◽  
The Subject ◽  
The Given ◽  
Insight Into

In my study, I list the directions of migration research, all from the point of view of public administration science. The emergence of migration research as an independent field is necessitated by the growth of migration. Researchers are researching the phenomenon of migration from their own field. Public administration uses a multidisciplinary, i.e. methodological approach of several disciplines, all of which is determined by the knowledge and nature of the subject of the given research. In the following, I review and evaluate the methodological directions of the research, which can provide an answer to a segment of the phenomenon of migration. The study gives an insight into research methods for migration research. It is not intended to present specific examples and procedures. At the end of the study, in possible directions, beyond the science of public administration, I list the organizations and faculties that are able to use the methodology of migration research.

scholarly journals THE CONCEPT OF DRAMATIZATION AND ITS MEANINGS

2019 ◽  
pp. 169-179
Author(s):  
Mikhail S. Nassonov ◽  
Keyword(s):  
Point Of View ◽  
Personality Characteristics ◽  
Common Features ◽  
Living State ◽  
Qualitative Level ◽  
The Subject ◽  
The Given ◽  
Further Development ◽  
Special Language ◽  
Strict Definition

Dramatization is a living, state-synthesizing, active internal activity peculiar to the subject; it is difficult to fit into a strict definition; thus, because of all the above, it appears to be a concept. Based on the peculiar methodology of Georges Bataille, with its goal to express the experience of the impossible, the categorical apparatus of M. Heidegger’s existential phenomenology, hermeneutics, historical and philosophical analysis and the use of the given concept, an attempt was made to penetrate the depths of the creative act and personality characteristics of the author. The latter (poet, philosopher) is engaged in mythopoiesis, he does not just create a special language and lives in it but conveys something through it, this being his destiny, his drama. In this regard, we should speak about the expression of Being, where dramatization plays a significant role. Dramatization is the process that helps to «go beyond oneself» to the unknown and transcendental. There are other meanings as well. For example, from an existential point of view, a person who dramatizes his existence becomes closer to understanding language, phenomena and the meaning of his life. Dramatization helps bridge the gap between things and words. The key figures of our research are Plato and G. Bataille, in whose philosophizing two types of dramatization are most clearly traced. The first type is rational, where drama unfolding in life and in one’s own philosophy is presented; the second one is irrational, associated with inner experience, mystical ecstasies, dramatization to exhaustion. At the same time, Plato and Bataille have common features: moments of experiencing death, incompleteness, and overcoming limits. This text may be of particular interest to those who deal with the philosophical problems of the creative process (further development of dramatization in relation to other similar concepts would help understand it at a higher qualitative level), a comparative analysis of antiquity and postmodernism.

Multiobjective Optimum Design of a Symmetric Parallel Schönflies-Motion Generator

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
O. Altuzarra ◽  
A. Hernandez ◽  
O. Salgado ◽  
J. Angeles
Keyword(s):  
Optimum Design ◽  
Closed Form Expression ◽  
Design Parameters ◽  
Pareto Optimum ◽  
Motion Generation ◽  
Form Expression ◽  
The Subject ◽  
Schönflies Motion ◽  
Objective Being ◽  
Motion Generator

The multiobjective optimization of a four-degree-of-freedom symmetric parallel manipulator for Schönflies-motion generation is the subject of this paper. First, the inverse positioning problem is discussed, along with its velocity analysis. The workspace is then analyzed, thereby deriving a closed-form expression of the workspace volume, which depends on the orientation of the moving platform. Next, the isotropic design of the manipulator is obtained. Then, the dexterity analysis of the manipulator is conducted, which is one objective of the optimum design of the manipulator, a second objective being a normalized workspace volume. Finally, the results of the optimization process are reported in terms of a set of Pareto-optimum pairs of the design parameters.

Derivation of the Mass Matrix for the McGill Schönflies Motion Generator

2011 ◽  
Vol 39 (2) ◽  
pp. 159-178 ◽  
Author(s):  
Giuseppe Carbone ◽  
Giuseppe Cannella ◽  
Jorge Angeles
Keyword(s):  
Mass Matrix ◽  
Schönflies Motion ◽  
Motion Generator

SOME RESULTS AND PROBLEMS RELATED TO UNIVERSAL ALGEBRAIC GEOMETRY

2007 ◽  
Vol 17 (05n06) ◽  
pp. 1133-1164 ◽  
Author(s):  
BORIS PLOTKIN
Keyword(s):  
Algebraic Geometry ◽  
Point Of View ◽  
Variety Of Algebras ◽  
Geometric Properties ◽  
Algebraic Sets ◽  
The Subject ◽  
Universal Algebraic Geometry ◽  
Future Work ◽  
The Given

In universal algebraic geometry (UAG), some primary notions of classical algebraic geometry are applied to an arbitrary variety of algebras Θ and an arbitrary algebra H ∈ Θ. We consider an algebraic geometry in Θ over the distinguished algebra H and we also analyze H from the point of view of its geometric properties. This insight leads to a system of new notions and stimulates a number of new problems. They are new with respect to algebra, algebraic geometry and even with respect to the classical algebraic geometry. In our approach, there are two main aspects: the first one is a study of the algebra H and its geometric properties, while the second is focused on studying algebraic sets and algebraic varieties over a "good", particular algebra H. Considering the subject from the second standpoint, the main goal is to get forward as far as possible in a classification of algebraic sets over the given H. The first approach does not require such a classification which is itself an independent and extremely difficult task. We also consider some geometric relations between different H1 and H2 in Θ. The present paper should be viewed as a brief review of what has been done in universal algebraic geometry. We also give a list of unsolved problems for future work.

scholarly journals Description of military apparatus in the Śrī-kālacakra-nāma-tantra-rāja

2008 ◽  
Vol 9 (1) ◽  
pp. 47-59
Author(s):  
Andrei Strelkov
Keyword(s):  
Point Of View ◽  
Russian Academy Of Sciences ◽  
The Subject ◽  
The Times ◽  
Oriental Studies ◽  
Academy Of Sciences ◽  
The Military ◽  
The Given

Russian Academy of Sciences, Institute of Oriental Studies, St. PetersburgIn the Śrī-kālacakra-nāma-tantra-rāja, a Buddhist treatise from the first half of the 11th century, there is a thematic fragment containing a description of military apparatus and their use in battles. In this article, the point of view that we are really dealing with a description of military apparatus and not with a symbolic description of the psychophysical practices of Buddhist yoga is developed. In our point of view, the reason for the subject of war being represented in this Buddhist work should be searched for in the reality of the tragic times in which the text was made―the times of destructive raids made on India by the ruler Mahmud of Ghazni. The article classifies the military apparatus mentioned in the Śrī-kālacakra-nāma-tantra-rāja, describes the basic technical characteristics of these mechanisms, and considers their function. The given subjects are considered with the drawing in the commentary Vimalaprabhā (11th century) and commentaries by Tibetan scholar Buton Rinchen Drub (1290–1364).

Modal Analysis Using Implicit Boundary Finite Element Methods

2014 ◽  
Author(s):  
Zhiyuan Zhang ◽  
Ashok V. Kumar
Keyword(s):  
Finite Element ◽  
Modal Analysis ◽  
Natural Frequencies ◽  
Mode Shapes ◽  
The Finite Element Method ◽  
B Spline ◽  
Boundary Method ◽  
Mass Matrices ◽  
Background Mesh ◽  
The Given

Modal analysis is widely used for linear dynamic analysis of structures. The finite element method is used to numerically compute stiffness and mass matrices and the corresponding eigenvalue problem is solved to determine the natural frequencies and mode shapes of vibration. Implicit boundary method was developed to use equations of the boundary to apply boundary conditions and loads so that a background mesh can be used for analysis. A background mesh is easier to generate because the elements do not have to conform to the given geometry and therefore uniform regular shaped elements can be used. In this paper, we show that this approach is suitable for modal analysis and modal superposition techniques as well. Furthermore, the implicit boundary method also allows higher order elements that use B-spline approximations. Several test examples are studied for verification.

Rosja wobec Partnerstwa Wschodniego Unii Europejskiej

2019 ◽  
Vol 17 (2) ◽  
pp. 41-64
Author(s):  
Agnieszka Legucka
Keyword(s):  
Foreign Policy ◽  
Point Of View ◽  
The Other ◽  
Research Approach ◽  
Eastern Partnership ◽  
The Subject ◽  
The One ◽  
The Given ◽  
The Eu

This article is devoted to the evaluation of the Eastern Partnership from the point of view of the implementation of Russia’s foreign policy. Using the research approach of constructivism, it analyses Russia’s attitude towards the EU’s Eastern Partnership project, as well as Russia’s reactions to the implementation of the EaP. Therefore, the subject of the analysis is not so much the relations of the EU and Russia with six states: Armenia, Azerbaijan, Belarus, Georgia, Moldova and Ukraine, as well as Russia’s and the EU’s narratives on its neighbourhood. This will make it possible to examine to what extent the position of one actor (EU) in relation to another (Russia) has been strengthened/weakened and, secondly, how the argumentation has promoted (the given message) in legitimizing the project as a whole, for both internal and external use. These projects were, on the one hand, Russia’s “close abroad” and, on the other, the EU’s “common neighbourhood”.

scholarly journals Parametric simulation of ceiling panels exposed to aggressive environments

2020 ◽  
Vol 310 ◽  
pp. 00010
Author(s):  
Iveta Hegedüsová ◽  
Sergej Priganc
Keyword(s):  
Cross Section ◽  
Subject Matter ◽  
Concrete Strength ◽  
Point Of View ◽  
Ultimate State ◽  
Cross Section Area ◽  
Section Area ◽  
The Subject ◽  
The Given

The subject matter of the contribution is findings obtained from a parametric simulation of ceiling panels behaviour under a change of determined parameters. The optional parameters included concrete strength, reinforcement cross-section area, and concrete covering. The experiment investigated an impact of the given parameters changes onto the element resistance which was evaluated on the basis of the ultimate state of usability, namely from the point of view of crack checking and deflection measuring. Panel behaviour was presented by a load-deflection relation and crack topography

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