Design of One-DOF Triangular Resch Pattern With Thick-Panel Origami

2018 ◽  
Author(s):  
Miao Zhang ◽  
Fufu Yang ◽  
Jiayao Ma ◽  
Yan Chen ◽  
Zhong You
Keyword(s):  
Kinematic Analysis ◽  
Degrees Of Freedom ◽  
Geometric Parameters ◽  
Engineering Applications ◽  
Large Pattern ◽  
The One ◽  
Doubly Curved ◽  
Panel Thickness

Resch patterns have a great potential to be utilized in many engineering applications, as they can be folded into curved profiles from planar sheets. They are rigid foldable but with a large number of degrees of freedom (DOF) when there are many units tessellating in the patterns, which constrains the applications due to the difficulty in control the motion symmetrically. In this paper, in order to achieve the single mobility for a limited number of triangular Resch pattern units, the thick-panel technique is employed at each vertex to reduce the DOF to one. Then the compatibility among all the vertices has to be satisfied by the systematical kinematic analysis on the geometric parameters of the Resch pattern and panel thickness. Eventually, two design schemes are obtained to form the one DOF origami structure with doubly-curved intermediate folding configurations, which could be further tessellated into a large pattern for various engineering applications.

Vertex-Splitting on a Diamond Origami Pattern

2019 ◽  
Vol 11 (3) ◽  
Author(s):  
Xiao Zhang ◽  
Yan Chen
Keyword(s):  
Degrees Of Freedom ◽  
The Other ◽  
Splitting Schemes ◽  
Engineering Applications ◽  
Splitting Technique ◽  
Kinematic Property ◽  
Vertex Splitting ◽  
The One ◽  
Three Degrees Of Freedom

A diamond origami pattern is a well-known origami pattern consisting of identical six-crease vertices. As each vertex can be modeled as a spherical 6R linkage with three degrees of freedom (DOF), the tessellated pattern with multiple vertices is a multi-DOF system, which makes it difficult to fully control the motion in the desired symmetric manner. Here, two splitting schemes on the diamond vertex are proposed to generate three types of unit patterns to reduce the DOF. This vertex-splitting technique is applied to the multivertex diamond origami pattern to produce several one-DOF basic assemblies, which form a number of one-DOF origami patterns. Two of the one-DOF origami patterns are discussed: one of which is a flat-foldable origami pattern mixed with four- and six-crease vertices and the other is a nonflat-foldable one mixed with four-, five-, and six-crease vertices. In the one-DOF patterns, the symmetrically kinematic property of the original diamond origami pattern is well kept. Such property would significantly facilitate engineering applications comparing to the multi-DOF origami patterns. It also paves a new road to construct one-DOF origami patterns.

Analysis and Optimization of a New Differentially Driven Cable Parallel Robot

2015 ◽  
Vol 7 (3) ◽  
Author(s):  
Hamed Khakpour ◽  
Lionel Birglen ◽  
Souheil-Antoine Tahan
Keyword(s):  
Kinematic Analysis ◽  
Design Methodology ◽  
Degrees Of Freedom ◽  
Parallel Robot ◽  
Cable Robot ◽  
Proper Design ◽  
Two Indices ◽  
Three Degrees Of Freedom ◽  
Cable Robots

In this paper, a new three degrees of freedom (DOF) differentially actuated cable parallel robot is proposed. This mechanism is driven by a prismatic actuator and three cable differentials. Through this design, the idea of using differentials in the structure of a spatial cable robot is investigated. Considering their particular properties, the kinematic analysis of the robot is presented. Then, two indices are defined to evaluate the workspaces of the robot. Using these indices, the robot is subsequently optimized. Finally, the performance of the optimized differentially driven robot is compared with fully actuated mechanisms. The results show that through a proper design methodology, the robot can have a larger workspace and better performance using differentials than the fully driven cable robots using the same number of actuators.

Nonlinear Dynamics of One-Way Clutches in Belt-Pulley Systems

2003 ◽  
Author(s):  
Farong Zhu ◽  
Robert G. Parker
Keyword(s):  
Nonlinear Dynamics ◽  
Degrees Of Freedom ◽  
Piecewise Linear ◽  
Primary Resonance ◽  
Harmonic Balance Method ◽  
Excitation Amplitude ◽  
Relative Displacement ◽  
Second Primary ◽  
Arc Length ◽  
The One

One-way clutches are frequently used in the serpentine belt accessory drives of automobiles and heavy vehicles. The clutch plays a role similar to a vibration absorber in order to reduce belt/pulley vibration and noise and increase belt life. This paper analyzes a two-pulley system where the driven pulley has a one-way clutch between the pulley and accessory shaft that engages only for positive relative displacement between these components. The belt is modeled with linear springs that transmit torque from the driving pulley to the accessory pulley. The one-way clutch is modeled as a piecewise linear spring with discontinuous stiffness that separates the driven pulley into two degrees of freedom (DOF). The harmonic balance method (HBM) combined with arc-length continuation is employed to illustrate the nonlinear dynamic behavior of the one-way clutch. HBM with arc-length continuation yields the stable and unstable periodic solutions for given parameters. These solutions are examined across a range of excitation frequencies. The results are confirmed by numerical integration and the widely used bifurcation software AUTO. At the first primary resonance, most of the responses are aperiodic, including quasiperiodic and chaotic solutions. At the second primary resonance, the peak bends to the left with classical softening nonlinearity because clutch disengagement decouples the pulley and the accessory over portions of the response period. The dependence on system parameters such as clutch stiffness, excitation amplitude, and inertia ratio between the pulley and accessory is studied to characterize the nonlinear dynamics across a range of conditions.

Topological defects in nematic films between planar degenerate surfaces. A Monte Carlo study

2021 ◽  
pp. 2250016
Author(s):  
Cesare Chiccoli ◽  
Paolo Pasini ◽  
Luiz Roberto Evangelista ◽  
Rodolfo Teixeira de Souza ◽  
Claudio Zannoni
Keyword(s):  
Monte Carlo ◽  
Boundary Conditions ◽  
Monte Carlo Simulations ◽  
Defect Structure ◽  
Topological Defects ◽  
Monte Carlo Study ◽  
Geometric Parameters ◽  
Molecular Organization ◽  
The One

The molecular organization of a nematic film sandwiched between two planar randomly aligned surfaces is studied by means of detailed Monte Carlo simulations. The formation as well as the evolution of topological defects induced by these particular boundary conditions are investigated. The resulting defect structure is compared with the one induced by hybrid aligned surfaces. The observation of such defects and some features of their structures can be associated with geometric parameters of the film and with properties of the confining surfaces.

An appropriate biomechanical model of seated human subjects exposed to whole-body vibration

2021 ◽  
pp. 146441932110394
Author(s):  
Raj Desai ◽  
Anirban Guha ◽  
Pasumarthy Seshu
Keyword(s):  
Degrees Of Freedom ◽  
Human Subjects ◽  
Computational Cost ◽  
Biomechanical Model ◽  
Whole Body ◽  
Body Parts ◽  
Lumped Parameter ◽  
Long Duration ◽  
The One ◽  
The Right

Long duration automobile-induced vibration is the cause of many ailments to humans. Predicting and mitigating these vibrations through seat requires a good model of seated human body. A good model is the one that strikes the right balance between modelling difficulty and simulation results accuracy. Increasing the number of body parts which have been separately modelled and increasing the number of ways these parts are connected to each other increase the number of degrees of freedom of the entire model. A number of such models have been reported in the literature. These range from simple lumped parameter models with limited accuracy to advanced models with high computational cost. However, a systematic comparison of these models has not been reported till date. This work creates eight such models ranging from 8 to 26 degrees of freedom and tries to identify the model which strikes the right balance between modelling complexity and results accuracy. A comparison of the models’ prediction with experimental data published in the literature allows the identification of a 12 degree of freedom backrest supported model as optimum for modelling complexity and prediction accuracy.

scholarly journals Conceptual Design and Computational Modeling Analysis of a Single-Leg System of a Quadruped Bionic Horse Robot Driven by a Cam-Linkage Mechanism

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Liangwen Wang ◽  
Weiwei Zhang ◽  
Caidong Wang ◽  
Fannian Meng ◽  
Wenliao Du ◽  
...  
Keyword(s):  
Motion Analysis ◽  
Kinematic Analysis ◽  
Degrees Of Freedom ◽  
Structural Parameters ◽  
Three Dimensional ◽  
Kinematic Modeling ◽  
Linkage Mechanism ◽  
Vector Method ◽  
Pressure Angle ◽  
End Point

In this study, the configuration of a bionic horse robot for equine-assisted therapy is presented. A single-leg system with two degrees of freedom (DOFs) is driven by a cam-linkage mechanism, and it can adjust the span and height of the leg end-point trajectory. After a brief introduction on the quadruped bionic horse robot, the structure and working principle of a single-leg system are discussed in detail. Kinematic analysis of a single-leg system is conducted, and the relationships between the structural parameters and leg trajectory are obtained. On this basis, the pressure angle characteristics of the cam-linkage mechanism are studied, and the leg end-point trajectories of the robot are obtained for several inclination angles controlled by the rotation of the motor for the stride length adjusting. The closed-loop vector method is used for the kinematic analysis, and the motion analysis system is developed in MATLAB software. The motion analysis results are verified by a three-dimensional simulation model developed in Solidworks software. The presented research on the configuration, kinematic modeling, and pressure angle characteristics of the bionic horse robot lays the foundation for subsequent research on the practical application of the proposed bionic horse robot.

A Novel 3-DOF Parallel Robot and its Kinematic Analysis

2014 ◽  
Vol 607 ◽  
pp. 759-763
Author(s):  
Xiao Bo Liu ◽  
Xiao Dong Yuan ◽  
Xiao Feng Wei ◽  
Wei Ni
Keyword(s):  
Motion Control ◽  
Kinematic Analysis ◽  
Degrees Of Freedom ◽  
Parallel Robot ◽  
Degree Of Freedom ◽  
The Novel ◽  
Forward Displacement ◽  
Simulation Based ◽  
Simulation Results

This paper deals with the design and analysis of a novel and simple two-translation and one-rotation (3 degrees of freedom, 3-dof) mechanism for alignment. Firstly, degree of freedom of the parallel robot is solved based on the theory of screw. Secondly considering the demand of motion control, we have conducted the analysis on the 3-dof parallel robot, which includes inverse displacement, forward displacement, and simulation based on SolidWorks Motion. The simulation results indicate that the novel 3-dof robot is suitable for performing the required operations.

2D MATTER WAVES GUIDED IN VAN DER WAALS POTENTIALS OF DIELECTRIC SURFACES

2009 ◽  
Vol 24 (08n09) ◽  
pp. 1764-1776
Author(s):  
WELITON M. SOARES ◽  
THIERRY PASSERAT DE SILANS ◽  
MARCOS ORIÁ ◽  
MARTINE CHEVROLLIER
Keyword(s):  
Degrees Of Freedom ◽  
Dipolar Interaction ◽  
Solid Surfaces ◽  
Matter Wave ◽  
Neutral Atoms ◽  
Periodic Surface ◽  
Matter Waves ◽  
Dielectric Surfaces ◽  
Low Dimensionality ◽  
The One

The dipolar interaction between neutral atoms and non-resonant surfaces results in attractive potentials.We describe here techniques to probe these interactions, particulary focussing in mechanisms to selectively prepare adsorption quantum states. The control of the external degrees of freedom of atoms very close to a surface allows one, in the one hand, to get values for the parameters of the potentials between neutral atoms and solid surfaces and, on the other hand, to develop schemes to explore matter behavior at low dimensionality. As an application for the 2D confined atomic matter-wave we consider Bloch oscillation for atoms in a periodic surface potential.

Inverse Static Analysis of a Planar System With Spiral Springs

2000 ◽  
Author(s):  
Marco Carricato ◽  
Joseph Duffy ◽  
Vincenzo Parenti-Castelli
Keyword(s):  
Static Analysis ◽  
External Load ◽  
Degrees Of Freedom ◽  
The Other ◽  
Linear Functions ◽  
State Variables ◽  
Planar System ◽  
Equilibrium Configurations ◽  
Solving Equations ◽  
The One

Abstract In this article the inverse static analysis of a two degrees of freedom planar mechanism equipped with spiral springs is presented. Such analysis aims to detect the entire set of equilibrium configurations of the mechanism once the external load is assigned. While on the one hand the presence of flexural pivots represents a novelty, on the other it extremely complicates the problem, since it brings the two state variables in the solving equations to appear as arguments of both trigonometric and linear functions. The proposed procedure eliminates one variable and leads to write two equations in one unknown only. The union of the root sets of such equations constitutes the global set of solutions of the problem. Particular attention has been reserved to the analysis of the “reliability” of the final equations: it has been sought the existence of critical situations, in which the solving equations hide solutions or yield false ones. A numerical example is provided. Also, in Appendix it is shown a particular design of the mechanism that offers computational advantages.

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