Synthesizing Single DOF Linkages Via Transition Linkage Identification

2007 ◽  
Vol 130 (2) ◽  
Author(s):  
Andrew P. Murray ◽  
Michael L. Turner ◽  
David T. Martin
Keyword(s):  
Classification Scheme ◽  
Degree Of Freedom ◽  
Physical Parameters ◽  
Single Degree Of Freedom ◽  
Loop Closure ◽  
Single Degree ◽  
The Matrix ◽  
Comprehensive Classification ◽  
Insight Into ◽  
Selection Of

A linkage is partially classified by identifying those links capable of unceasing and drivable rotation and those that are not. In this paper, we examine several planar single degree-of-freedom linkages to identify all changes to the physical parameters that may alter this classification. The limits on the physical parameters that result in no change in the classification are defined by transition linkages. More rigorously, a transition linkage possesses a configuration at which the matrix defined by the derivative of the loop closure equations with respect to the joint variables loses rank. Transition linkages divide the set of all linkages into different classifications. In the simplest cases studied, transition linkage identification produces a comprehensive classification scheme. In all cases, this identification is used to alter a linkage’s physical parameters without changing its classification and produces insight into the selection of these parameters to produce a desired classification.

Kinematics and Dynamics Analysis of the Lifting System of a Welding and Tube-Transferring Car for Deepwater Pipe-Laying Vessels

2011 ◽  
Vol 199-200 ◽  
pp. 32-40
Author(s):  
Yi Lai Ma ◽  
Li Lin ◽  
Xian Wen Liu
Keyword(s):  
Dynamic Analysis ◽  
Reaction Force ◽  
Degree Of Freedom ◽  
Kinematics And Dynamics ◽  
Dynamics Analysis ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
Support Reaction ◽  
Lifting System ◽  
Selection Of

The tube-transferring car is a key part of transportation system for deepwater pipe-laying vessels. This paper covers the design of a tube-transferring car for deep sea pipe-laying, especially its lifting mechanism. Kinematics and dynamics analysis of the lifting mechanism is conducted. During dynamic analysis and calculation, the single degree of freedom mechanical system dynamic analysis method is used. The results show that the rotation angle of the lifting system has a direct impact on the lifting speed and driving force. The support reaction force in each kinematic pair which is calculated by choosing the single degree of freedom dynamics provides a theoretical basis for the design of the lifting mechanism, which is finally reflected in the selection of horizontal drive of the feeding machine and the related parameter design．

An Experimental Study of a Single-Degree-of-Freedom Impact Oscillator

2021 ◽  
Author(s):  
Shun Zhong ◽  
Jingyuan Tan ◽  
Zhicheng Cui ◽  
Tanghong Xu ◽  
Liqing Li
Keyword(s):  
Dynamical Behavior ◽  
Degree Of Freedom ◽  
Experimental Results ◽  
Physical Parameters ◽  
Impact Oscillator ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
Design Choice ◽  
Wide Range ◽  
Simulation Results

Purpose. Impacts appear in a wide range of mechanical systems. To study the dynamical behavior introduced by impact in practical way, a single-degree-of-freedom impact oscillator rig is designed. Originality. A simple piece-wise linear system with symmetrical flexible constraints is designed and manufactured to carry out a wide range of experimental dynamic analysis and ultimately to validate piece-wise models. The new design choice is based on the following criteria: accuracy in representing the mathematical model, manufacturing simplicity, flexibility in terms of parameter changes and cost effectiveness as well avoidance of the delay introduced by the structure. Meanwhile, the new design provides the possibility of the applications of the complex control algorithms. Design/methodology/approach. The design process is described in detail. The initial experimental results of the rig as well as numerical simulation results are given. In this rig, the mass driven force is generated by electromagnet, which can be adjusted and control easily. Also, most of the physical parameters can be varied in a certain range to enhance flexibility of the system allowing to observe subtle phenomena. Findings. Compared with the simulation results, the designed rig is proved to be validated. Then, the initial experimental results demonstrate potentials of this rig to study fundamental impact phenomena, which have been observed in various engineering systems. They also indicate that this rig can be a good platform for investigating nonlinear control methods.

Broadband Lg Magnitude

1987 ◽  
Vol 58 (4) ◽  
pp. 125-133 ◽  
Author(s):  
R. B. Herrmann
Keyword(s):  
Correction Term ◽  
Seismic Source ◽  
Degree Of Freedom ◽  
Source Spectrum ◽  
Simulation Studies ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
Anelastic Attenuation ◽  
Definition Of ◽  
Insight Into

Abstract The application of the Nuttli (1973) definition of mbLg to observations with periods away from 1.0 seconds as suggested by Boore and Atkinson (1987) and Atkinson and Boore (1987) is studied with emphasis on observations in the 1.0 –10.0 second range and on single degree of freedom seismographs. Simulation studies indicate the efficacy of this usage, but also provides insight into the interrelated effects of the instrument, anelastic attenuation and the seismic source on observed amplitudes. In order to relate a broadband Lg magnitude to the source spectrum, a correction term must be applied to the mLg (f) relation of Herrmann and Kijko (1983).

Laguerre Series Solutions of the Delayed Single Degree-of-Freedom Oscillator Excited by an External Excitation and Controlled by a Control Force

2018 ◽  
Vol 15 (2) ◽  
pp. 606-610 ◽  
Author(s):  
Nurcan Baykuş Savaşaneril
Keyword(s):  
Laguerre Polynomials ◽  
Degree Of Freedom ◽  
Control Force ◽  
Numerical Application ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
Laguerre Series ◽  
Analysis Technique ◽  
The Matrix ◽  
Fundamental Systems

With increasing technologies, applications of delayed models are more frequently encountered in biology, physics and various fields of engineering. The single degree-of-freedom oscillator, on the other hand, is one of the fundamental systems in many physics and engineering problems; thus, solving the equation of this problem would serve for many other sophisticated problems. In this study, a novel and simple numerical method for the solution of this system is introduced in the matrix form based on Laguerre polynomials. The method is exemplified through a numerical application and the results obtained are compared with those of another method. In addition, an error analysis technique based on residual function is developed and applied to this problem to demonstrate the validity and applicability of the method. The convenience of the method is that it is quite simple to employ by using computer programs.

The Case for a General Method of Kinematic Analysis of Plane Mechanisms Based on Equations of Constraint

1995 ◽  
Vol 209 (5) ◽  
pp. 337-343 ◽  
Author(s):  
A A Fogarasy ◽  
M R Smith
Keyword(s):  
Kinematic Analysis ◽  
Degree Of Freedom ◽  
Adequate Description ◽  
Single Degree Of Freedom ◽  
Constraint Equations ◽  
Single Degree ◽  
Motion Characteristics ◽  
Clear Line ◽  
Selection Of ◽  
General Method

All but the simplest of single degree of freedom mechanisms have a relatively large number of component parts. To analyse the motion of such systems, therefore, one parameter is rarely sufficient. For an adequate description of the motion characteristics of all components, a number of additional coordinates are needed. This paper introduces a clear and logical notation which facilitates the setting up of the required number of constraint equations by simple inspection of clear line diagrams of the mechanism to be analysed. These constraint equations are eminently suitable for the calculation of velocities and accelerations by direct differentiation. The resulting equations are linear in the velocities and accelerations of all component parts. A method based on this approach is presented and applied to a selection of widely different examples.

scholarly journals Design of Anti-Parallelogram Loop Assemblies

2019 ◽  
Vol 60 (3) ◽  
pp. 232-240
Author(s):  
Şebnem Gür ◽  
Koray Korkmaz ◽  
Gökhan Kiper
Keyword(s):  
Degree Of Freedom ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
Assembly Method ◽  
Design Alternatives ◽  
Alternative Approach ◽  
The Subject ◽  
Planar Linkages ◽  
Symmetry Operations ◽  
Selection Of

Scissor mechanisms are frequently used for deployable structures and many studies have been conducted on the subject. Most of the studies consider scissor units as modules in the design process. An alternative approach is to utilize loops as the modules for design. In this paper, the design alternatives of single degree-of-freedom planar linkages comprising anti-parallelogram loops using the loop assembly method is presented. First, scissor mechanisms are reviewed. Next, the types of four-bar loops and the resulting linkages in the literature are introduced and those which are yet to be explored, anti-parallelogram being one of them, are identified. Then the loop assembly method and the examples in the literature are reviewed. As a method to form as many alternatives as possible, symmetry operations are proposed. Suitable frieze symmetry groups utilized for obtaining the assemblies are explained and the anti-parallelogram loop patterns are derived. Next, the single degree-of-freedom linkages are obtained from the loop assemblies. Finally, a selection of the resulting linkages with novel properties are presented. This study shows that loop assemblies are efficient in systematic type synthesis of scissor linkages, some types of which could not be foreseen by using units as modules.

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