scholarly journals RESEARCH CONCERNING THE STATIC BALANCING OF A MULTILOOP LINKAGE

2021 ◽  
Vol 2(73) (1) ◽  
pp. 82-89
Author(s):  
Dorin Bădoiu
Keyword(s):  
Static Balancing ◽  
Independent Loops

In the paper a method for achieving the total static balancing of a linkage with two independent loops is presented. There are also analyzed two solutions for partial static balancing of the studied linkage. Finally, a series of results of the simulations performed in the studied balancing cases are given.

scholarly journals A Kinematical Analysis of the Flap and Wing Mechanism of a Light Sport Aircraft Using Topological Models

Symmetry ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1243
Author(s):  
Sorin Vlase ◽  
Ion-Marius Ghiţescu ◽  
Marius Paun
Keyword(s):  
Graph Theory ◽  
Mechanical System ◽  
Linear Systems ◽  
Kinematic Analysis ◽  
Control Mechanism ◽  
Practical Application ◽  
Dynamic Level ◽  
New Formulation ◽  
Topological Models ◽  
Independent Loops

In this, paper, we propose a method of kinematic analysis of a planar mechanism with application to the flap and wing mechanism of a light sport aircraft. A topological model is used to describe a mechanical system, which is a model that allows the study of the maneuverability of the system. The proposed algorithm is applied to determine the velocity and acceleration field of this multibody mechanical system. The graph associated with the mechanical system is generated in a new formulation and based on it, the fundamental loops of the graph are identified (corresponding to the independent loops of the mechanism), the equations for closing vectorial contours are written, and the kinematic conditions for determining velocities and accelerations and the associated linear systems are solved, which provides the field of speeds and accelerations. Graph Theory is applied at a kinematic level and not at a dynamic level, as in previous studies. A practical application for the kinematic analysis of the control mechanism of a light aircraft illustrates the proposed method.

scholarly journals Relationships between the Rider’s Pelvic Mobility and Balance on a Gymnastic Ball with Equestrian Skills and Effects on Horse Welfare

Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 453
Author(s):  
Mette Uldahl ◽  
Janne W. Christensen ◽  
Hilary M. Clayton
Keyword(s):  
Heart Rate ◽  
Negative Correlation ◽  
Core Stability ◽  
Static Balancing ◽  
Conflict Behaviors ◽  
Video Recordings ◽  
Highly Correlated ◽  
And Control ◽  
Energetic Performance ◽  
Working Heart

Riders need core stability to follow and guide the horse’s movements and avoid giving unintended or conflicting signals. This study evaluated the rider’s performance of exercises on a gymnastic ball with on-horse performance and indicators of stress in the horse. Twenty experienced riders were scored performing three exercises on a gymnastic ball and for quality and harmony when riding based on evaluation of video recordings in which conflict behaviours were evident. The horse’s heart rate and number of conflict behaviors during the riding test and cortisol levels after completion of the test were measured. The rider’s ability to roll the pelvis from side-to-side on a gymnastic ball was highly correlated with ability to circle the pelvis on the ball and with quality and harmony during riding. However, pelvic roll and riding quality and harmony showed a trend toward a negative correlation with balancing skills on the ball. It appears that the ability to actively move the pelvis is more relevant to equestrian performance than static balancing skill. Horses ridden by riders with better pelvic mobility and control showed significantly fewer conflict behaviors. On the contrary, high scores for balancing on the gymnastic ball were negatively correlated with the horses’ working heart rates, suggesting a less energetic performance. Pelvic control and mobility may be predictive for equestrian skills and riding harmony.

Structure Based Grading of Kinematic Chains

2014 ◽  
Vol 575 ◽  
pp. 501-506 ◽  
Author(s):  
Shubhashis Sanyal ◽  
G.S. Bedi
Keyword(s):  
Structural Properties ◽  
Structural Property ◽  
Kinematic Chain ◽  
Degree Of Freedom ◽  
Kinematic Chains ◽  
Structural Differences ◽  
The Individual ◽  
Independent Loops

Kinematic chains differ due to the structural differences between them. The location of links, joints and loops differ in each kinematic chain to make it unique. Two similar kinematic chains will produce similar motion properties and hence are avoided. The performance of these kinematic chains also depends on the individual topology, i.e. the placement of its entities. In the present work an attempt has been made to compare a family of kinematic chains based on its structural properties. The method is based on identifying the chains structural property by using its JOINT LOOP connectivity table. Nomenclature J - Number of joints, F - Degree of freedom of the chain, N - Number of links, L - Number of basic loops (independent loops plus one peripheral loop).

The Automatic Generation of a Mathematical Model for Machinery Systems

1973 ◽  
Vol 95 (2) ◽  
pp. 629-635 ◽  
Author(s):  
D. A. Smith ◽  
M. A. Chace ◽  
A. C. Rubens
Keyword(s):  
Mathematical Model ◽  
Graph Theory ◽  
Computer Program ◽  
Mechanical System ◽  
Input Data ◽  
Automatic Generation ◽  
Electrical Networks ◽  
Lagrange’S Equation ◽  
Detailed Explanation ◽  
Independent Loops

This paper presents a detailed explanation of a technique for automatically generating a mathematical model for machinery systems. The process starts from a relatively small amount of input data and develops the information required to model a mechanical system with Lagrange’s equation. The technique uses elements of graph theory which were developed for electrical networks. The basic identifications required for mechanical systems are: paths from ground to mass centers, the independent loops of parts, if any, and paths associated with applied force effects. The techniques described in this paper have been used successfully in a generalized computer program, DAMN.

scholarly journals Total Static Balancing and Kinetostatics of the 3R Base Cinematic Chain

2018 ◽  
Vol 2 (1) ◽  
pp. 1-13
Author(s):  
Relly Victoria Petrescu ◽  
Raffaella Aversa ◽  
Antonio Apicella ◽  
Florian Ion Tiberiu Petrescu
Keyword(s):  
Static Balancing

Combined Graph Layout Algorithms for Automated Sketching of Kinematic Chains

2012 ◽  
Author(s):  
Martín A. Pucheta ◽  
Nicolás E. Ulrich ◽  
Alberto Cardona
Keyword(s):  
Computational Cost ◽  
Kinematic Chain ◽  
Initial Position ◽  
Graph Representation ◽  
Combinatorial Algorithms ◽  
Graph Layout ◽  
Kinematic Chains ◽  
Aesthetic Characteristics ◽  
Edge Crossings ◽  
Independent Loops

The graph layout problem arises frequently in the conceptual stage of mechanism design, specially in the enumeration process where a large number of topological solutions must be analyzed. Two main objectives of graph layout are the avoidance or minimization of edge crossings and the aesthetics. Edge crossings cannot be always avoided by force-directed algorithms since they reach a minimum of the energy in dependence with the initial position of the vertices, often randomly generated. Combinatorial algorithms based on the properties of the graph representation of the kinematic chain can be used to find an adequate initial position of the vertices with minimal edge crossings. To select an initial layout, the minimal independent loops of the graph can be drawn as circles followed by arcs, in all forms. The computational cost of this algorithm grows as factorial with the number of independent loops. This paper presents a combination of two algorithms: a combinatorial algorithm followed by a force-directed algorithm based on spring repulsion and electrical attraction, including a new concept of vertex-to-edge repulsion to improve aesthetics and minimize crossings. Atlases of graphs of complex kinematic chains are used to validate the results. The layouts obtained have good quality in terms of minimization of edge crossings and maximization of aesthetic characteristics.

Towards Parallel Cable-Driven Pantographs

2011 ◽  
Author(s):  
Simon Perreault ◽  
Philippe Cardou ◽  
Cle´ment Gosselin
Keyword(s):  
Low Cost ◽  
Output Link ◽  
Static Balancing ◽  
New Class ◽  
Nonlinear Springs ◽  
Preliminary Validation ◽  
Important Challenge ◽  
History Of ◽  
Working Principle ◽  
Two Degree Of Freedom

We propose a new class of pantographs, i.e., of mechanisms that allow the reproduction of the displacements of an input link, the master, with an output link, the slave. The application we envision for these devices is the telemanipulation of objects from small distances, at low cost, where magnetic fields or other design constraints prohibit the use of electromechanical systems. Despite the long history of pantographs, which were invented in the 17th century, the class of pantographs proposed here is new, as it relies on parallel cable-driven mechanisms to transmit the motion. This allows the reproduction of rigid-body displacements, while previous pantographs were limited to point displacements. This important characteristic and others are described in the paper. One important challenge in the design of the proposed systems is that the cables must remain taut at all time. We address this issue by introducing nonlinear springs that passively maintain a minimum tension in the cables, while approximating static balancing of the mechanism over its workspace. Approximating static balancing allows the forces applied at the slave to reflect more accurately at the master, and vice versa. As a preliminary validation, a two-degree-of-freedom parallel cable-driven pantograph is designed. A prototype of this apparatus that does not include approximate static balancing is built, which demonstrates the working principle of these mechanisms.

scholarly journals AN INDEPENDENT LOOPS SEARCH ALGORITHM FOR SOLVING INDUCTIVE PEEC LARGE PROBLEMS

2012 ◽  
Vol 23 ◽  
pp. 53-63 ◽  
Author(s):  
Trung-Son Nguyen ◽  
Jean-Michel Guichon ◽  
Olivier Chadebec ◽  
Gerard Meunier ◽  
Benjamin Vincent
Keyword(s):  
Search Algorithm ◽  
Independent Loops
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