Structural and Kinematic Analysis of the Isomorphic Mechanism of a Parallel Structure for Translational Movements of the Output Link

2021 ◽  
pp. 35-40
Author(s):  
T.V. Edakina ◽  
A.I. Edakin ◽  
V.V. Samoilova ◽  
V.S. Ramzhaev
Keyword(s):  
Degrees Of Freedom ◽  
Three Dimensional ◽  
Kinematic Chain ◽  
Parallel Structure ◽  
Dimensional Model ◽  
Output Link ◽  
Three Dimensional Model ◽  
Industrial Enterprises ◽  
Three Degrees Of Freedom

The article considers the mechanism of a parallel structure with three degrees of freedom, having the property of isomorphism. The ratio between the movements in the drive and the movements of the output link is constant. This is due to the fact that all linear drivers are located parallel to the corresponding axes of the fixed coordinate system, and in each kinematic chain there are two rotational kinematic pairs, the which axes are parallel to the axes of the corresponding linear drivers. In addition, each kinematic chain has two dyads that provide linear motion of the linear driver rod. On the basis of the developed three-dimensional model, a structural analysis of the mechanism with determination of the number of degrees of freedom and solving the problem of its positions was carried out. The proposed mechanism can be applied in many areas of activity of industrial enterprises, including additive technologies due to the growth of automation, robotization and the development of artificial intelligence.

Designing Statically Determinable Mechanisms of Technological Mechatronic Machines with Parallel Kinematics

2019 ◽  
Vol 20 (7) ◽  
pp. 428-436
Author(s):  
A. K. Tolstosheev ◽  
V. A. Tatarintsev
Keyword(s):  
Structural Analysis ◽  
Hierarchical Structure ◽  
Degrees Of Freedom ◽  
Kinematic Chain ◽  
Parallel Structure ◽  
Parallel Kinematics ◽  
Output Link ◽  
Parallel Connection ◽  
Kinematic Chains ◽  
Chain Increase

The work is devoted to improving the reliability and manufacturability of mechatronic machine designs with parallel kinematics by replacing statically indeterminable manipulators with statically determinable mechanisms. A technique is proposed in which the design of statically determinable manipulators of technological mechatronic machines with parallel kinematics is performed by modifying the structure of prototypes and includes three steps: identifying and analyzing redundant links, eliminating redundant links, checking the correctness of eliminating redundant links. To determine the number of degrees of freedom of the mechanism, identify redundant links, and verify the solution, the authors use the proposed methodology for structural analysis of parallel structure mechanisms. In structural analysis, a manipulator is represented by a hierarchical structure and is considered as a parallel connection of elementary mechanisms with an open kinematic chain; as a kinematic chain consisting of leading and driven parts; as a set of links and kinematic pairs; as a kinematic connection of the output link and the rack. The article implements the following techniques for eliminating redundant links: mobility increase in kinematic pairs; introduction of unloading links and passive kinematic pairs to the kinematic chain; exclusion of extra links and pairs from the kinematic chain; increase in mobility in some kinematic pairs simultaneously with the exclusion of other kinematic pairs that have become superfluous. The authors developed several variants of structural schemes of self-aligning manipulators based on the Orthoglide mechanism, which retain the basic functional proper ties of the prototype. To increase the number of self-aligning mechanism diagrams, the redistribution of mobilities and links within the connecting kinematic chain and between connecting kinematic chains is used. The proposed methodics allow to determine the number of degrees of freedom of the mechanism, the number and type of redundant links, eliminate redundant links and, on an alternative basis, build structural diagrams of statically determinable mechanisms of technological mechatronic machines with parallel kinematics.

scholarly journals КОМП’ЮТЕРНА ТЕХНОЛОГІЯ АНАЛІЗУ ТА ДИЗАЙНУ ПРЕДМЕТНОГО СЕРЕДОВИЩА З ПОЗИЦІЇ ВІЗУАЛЬНОГО СПРИЙНЯТТЯ

2020 ◽  
pp. 39-48
Author(s):  
Т. В. Булгакова ◽  
О. В. Полякова ◽  
С. С. Кисіль ◽  
О. Є. Шмельова
Keyword(s):  
Visual Perception ◽  
Quantitative Determination ◽  
Three Dimensional ◽  
Geometrical Model ◽  
Human Being ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Three Dimensional Objects ◽  
Computer Technologies

The purpose of the investigation is the development of computer technology of analysis and design of built environment from the point of its visual perception in the space of its three-dimensional model without using the perspective projections. The methodology were used to achieve the purpose: analysis of the scientific publications on the topic of object environment composition; applied geometry methods, method of division of the geometrical object into simplexes (triangulation), methods of advanced algebra and analytical geometry; computer modeling for construction of the model of visual perception of the environment. Methods of analysis of the three-dimensional model on the basis of modeling of visual perception by means of computer technologies directly in the area of the model without using perspective projections are developed. It is offered to analyze the visual perception of any objects and their relations by means of using the solid angles with the vertices placed in the point of view and the surfaces that surround the visible contours of three-dimensional objects. This approach gives the opportunity to analyze the objects simultaneously regardless their position according to the observer; apart of that, the objects, which are accepted similarly in the reality, will have the same geometrical features during the modeling of visual perception and beside that, the refusal of using of the perspective projections will make possible to avoid the distortion of the images. The algorithm of determination of the solid angles to three-dimensional objects, which is the basis of computer methods of compositional analysis of the object environment from the position of visual perception without the use of perspective projections, is developed. The geometrical model of visual perception by a human being from the certain point of perception is built. It makes possible to define correctly visual features of the object environment and gives the opportunity to analyze the whole surrounding of the observer in the area of 360 degrees. Scientific novelty of the investigation means that the methods of analysis of the three-dimensional model on the basis of modeling of visual perception by means of computer technologies directly in the area of the model without using perspective projections are developed for the first time. The concept of the geometrical model of visual perception by a human being from the certain point of perception is developed. The further development of the methodology of quantitative determination of characteristics of object environment by means of computer technologies is defined. Practical significance shows that the results of the scientific investigation can be used for analysis and judgments of the aesthetic peculiarities of the object environment by means of computer technologies with quantitative determination of characteristics of object environment from the point of its visual perception. Such approach gives the opportunity to develop and create the further certain recommendations and instructions for correction of the existing environment and for the development of the new one.

Three-dimensional model predictive controller design for approach to landing with microburst encounter

2017 ◽  
Vol 232 (11) ◽  
pp. 2034-2047 ◽  
Author(s):  
A Hassanpour ◽  
Seid H Pourtakdoust
Keyword(s):  
Degrees Of Freedom ◽  
Controller Design ◽  
Equations Of Motion ◽  
Three Dimensional ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Model Predictive Controller ◽  
Predictive Controller ◽  
Lateral Displacements ◽  
Alternative Routes

Microburst is considered an extreme powerful hazard for aircrafts, especially during takeoff, approach and landing phases of flight. Current airborne piloting practices involve taking alternative routes, if early detection of microburst wind shear (MBW) for its effective avoidance is possible. In this respect, design and analysis of precision automatic flight path control systems for microburst penetration are of outmost importance whose success can significantly reduce crash risks and thus enhance the flight safety. The current study is focused on the design and analysis of a three-dimensional model predictive controller for a wide body transport type aircraft encountering MBW in approach to landing phase of flight. This task is performed utilizing the full nonlinear six degrees of freedom aircraft equations of motion and the most complete 3D model of the MBW and its gradients. The results are promising for online applications as the proposed model predictive controller-based controller has effectively guided and kept the aircraft on the approach glide path with negligible deviations against aircraft initial lateral displacements, sharp edge gust disturbance as well as the MBW.

scholarly journals Automatic determination of an anatomical coordinate system for a three-dimensional model of the human patella

2013 ◽  
Vol 46 (12) ◽  
pp. 2093-2096 ◽  
Author(s):  
Michael J. Rainbow ◽  
Daniel L. Miranda ◽  
Roy T.H. Cheung ◽  
Joel B. Schwartz ◽  
Joseph J. Crisco ◽  
...  
Keyword(s):  
Coordinate System ◽  
Three Dimensional ◽  
Dimensional Model ◽  
Automatic Determination ◽  
Three Dimensional Model

Love-wave propagation in a three-dimensional sedimentary basin

1992 ◽  
Vol 82 (4) ◽  
pp. 1661-1677 ◽  
Author(s):  
Takumi Toshinawa ◽  
Tatsuo Ohmachi
Keyword(s):  
Finite Element ◽  
Wave Propagation ◽  
Love Wave ◽  
Degrees Of Freedom ◽  
Three Dimensional ◽  
Sedimentary Basins ◽  
Two Dimensional ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Time Histories

Abstract A simplified three-dimensional finite-element method has been developed for simulation of Love-wave propagation in three-dimensional sedimentary basins. The eigenfunctions for the fundamental-mode surface waves are employed as interpolation functions in the finite-element scheme. By reducing the number of degrees of freedom, the method enables us to analyze wave propagation in an area of 2000 km2 as large as the southern part of the Kanto plain, Japan. Time histories of the near Izu-Ohshima earthquake of 1990 are calculated and compared with observation. Calculated displacement snapshots show the effect of three-dimensional topography on direction of Love-wave propagation. The three-dimensional simulation is also compared with a two-dimensional one, demonstrating amplitude increase and extended duration. Time histories and their spectra from the three-dimensional model show better agreement with the observations than those from the two-dimensional model.

scholarly journals Development of a technique of the automated construction of 3D models of standard mass transfer trays

2018 ◽  
Vol 224 ◽  
pp. 04027 ◽  
Author(s):  
Rimma Tukaeva ◽  
Vitalliy Afanasenko ◽  
Petr Kulakov
Keyword(s):  
Mass Transfer ◽  
Model Development ◽  
Three Dimensional ◽  
3D Models ◽  
Dimensional Model ◽  
Valve Tray ◽  
Three Dimensional Model ◽  
Design Efficiency ◽  
Industrial Enterprises ◽  
Regulatory Documents

The main elements of most mass-transfer columns of industrial enterprises are contact trays which are formed by various details inside the apparatus. The dimensions of the details are standardized and regulated by regulatory documents. under modern conditions of equipment designing it is necessary to develop three-dimensional model of typical assembly units, that is a very time-consuming task. The article considers the way to improve the design efficiency by automation of the process of standard mass-transfer valve tray model development in Kompas 3D system with MySQL application.

scholarly journals Strength analysis of an off-road lorry frame

2021 ◽  
Vol 110 ◽  
pp. 23-33
Author(s):  
Ján DIŽO ◽  
Miroslav BLATNICKÝ ◽  
Paweł DROŹDZIEL ◽  
Stanislav SEMENOV ◽  
Evgeny MIKHAILOV ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Degrees Of Freedom ◽  
Structural Unit ◽  
Three Dimensional ◽  
Strength Analysis ◽  
The Finite Element Method ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Definition Of ◽  
Distribution Of Stresses

The lorry frame is the main carrying part of a lorry, composed of several components. These components are connected by joints into one structural unit and it forms the lorry chassis. The contribution of this article is focused on the strength analyses of a backbone frame, which is used on an off-road lorry chassis. Strength analyses are carried out utilising the finite element method. This article presents a created three-dimensional model of the frame and definition of boundary conditions (loads, the definition of degrees of freedom) needed for simulation computations. Results of the numerical calculations are the main parts of this article. Attention is mainly centred on the distribution of stresses of the frame under defined loads and its deformations.

scholarly journals Molecular Dynamic Simulation of Water Vapor and Determination of Diffusion Characteristics in the Pore

2018 ◽  
Vol 173 ◽  
pp. 06009 ◽  
Author(s):  
Eduard G. Nikonov ◽  
Miron Pavluš ◽  
Mária Popovičová
Keyword(s):  
Water Vapor ◽  
Building Materials ◽  
Three Dimensional ◽  
Dimensional Model ◽  
Pore System ◽  
Three Dimensional Model ◽  
Diffusion Parameters ◽  
Dead End ◽  
Diffusion Characteristics

One of the varieties of pores, often found in natural or artificial building materials, are the so-called blind pores of dead-end or saccate type. Three-dimensional model of such kind of pore has been developed in this work. This model has been used for simulation of water vapor interaction with individual pore by molecular dynamics in combination with the diffusion equation method. Special investigations have been done to find dependencies between thermostats implementations and conservation of thermodynamic and statistical values of water vapor – pore system. The two types of evolution of water – pore system have been investigated: drying and wetting of the pore. Full research of diffusion coefficient, diffusion velocity and other diffusion parameters has been made.

Three-Dimensional Interactions in a Two-Segment Kinetic Chain. Part I: General Model

1989 ◽  
Vol 5 (4) ◽  
pp. 403-419 ◽  
Author(s):  
Michael E. Feltner ◽  
Jesús Dapena
Keyword(s):  
Three Dimensional ◽  
Angular Acceleration ◽  
Dimensional Model ◽  
Body Segment ◽  
Kinetic Chain ◽  
Three Dimensional Model ◽  
Joint Torques ◽  
Arm Motions ◽  
Acceleration Vector

The motion of a body segment is determined by joint torques and by the motions of the segments proximal or distal to it. This paper describes a three-dimensional model that was used to determine the effects of the shoulder and elbow joint torques and of the upper trunk and arm motions on the angular accelerations of the arm segments during baseball pitching. Equations were developed to fractionate the three-dimensional components of the angular acceleration vector of each segment into angular acceleration terms associated with the joint torques made on the segment, and into various “motion-dependent” angular acceleration terms associated with the kinematic variables of the arm segments. Analysis of the values of the various motion-dependent angular acceleration terms permitted the determination of their contributions to the motion of the segment. Although the model was developed to provide further understanding of the mechanics of the throwing arm during baseball pitching, it can be used to analyze any two-segment two-dimensional or three-dimensional motion.

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