scholarly journals Design and analysis of a novel deployable hexagonal prism module for parabolic cylinder antenna

2021 ◽  
Vol 12 (1) ◽  
pp. 9-18
Author(s):  
Xiaofei Ma ◽  
Yang Li ◽  
Tuanjie Li ◽  
Hangjia Dong ◽  
Dawei Wang ◽  
...  
Keyword(s):  
Degree Of Freedom ◽  
Parabolic Cylinder ◽  
Hexagonal Prism ◽  
Axis Direction ◽  
Simulation And Experiment ◽  
Deployable Mechanism ◽  
Basic Loop

Abstract. This paper presents a novel deployable hexagonal prism module for parabolic cylinder antennas that exhibit characteristics of geometric scalability. The hexagonal prism module consists of six basic rib mechanisms distributed along the axis and parabolic directions of the parabolic cylinder. The basic rib mechanism along the axis direction is designed, and the position of each member in the deployed state is calculated according to the geometric relationships at the folded state. The basic rib mechanism along the parabolic direction is designed to ensure that the mechanism can be fully folded. The degree of freedom of basic loop mechanisms consisting of four basic rib mechanisms due to the splice of multiple modules is analyzed. The degree of freedom of the proposed hexagonal prism module is verified through simulations and experiments of a deployable mechanism composed of three hexagonal prism modules. The simulation and experiment results show that the proposed hexagonal prism module can offer synchronized and coordinated movement during the deployment process.

Design and Mobility Analysis of Large Deployable Mechanisms Based on Plane-Symmetric Bricard Linkage

2016 ◽  
Author(s):  
Xiaozhi Qi ◽  
Bing Li ◽  
Zhihuai Miao ◽  
Hailin Huang
Keyword(s):  
Computer Aided Design ◽  
Closed Loop ◽  
Degree Of Freedom ◽  
Mobility Analysis ◽  
Plane Symmetric ◽  
Analysis And Design ◽  
Geometric Conditions ◽  
Deployable Mechanism ◽  
Vertical Bars ◽  
Aided Design

In this paper, a class of large deployable mechanisms constructed by plane-symmetric Bricard linkage is presented. The plane-symmetric Bricard linkage is a closed-loop over-constrained spatial mechanism composed of six hinge-jointed bars, which has one plane of symmetry during its deployment process. The kinematic analysis of the linkage is presented from the perspectives of geometric conditions, closure equations and degree of freedom. The results illustrates that the linkage has one degree of freedom, and it can be deployed from the folded configuration to one rectangle plane. Therefore, the plane-symmetric Bricard linkage can be used to construct lager deployable mechanism as basic deployable unit. Four plane-symmetric Bricard linkages can be assembled to a quadrangular module by sharing the vertical bars of adjacent units. The module is a multi-loop deployable mechanism and has one degree of freedom by the mobility analysis. Large deployable mast, deployable plane truss and deployable ring are built by a plurality of plane-symmetric Bricard linkages. The computer-aided design models for typical examples are built to illustrate their feasibility and validate the analysis and design methods.

Geometric Design of a Bio-Inspired Flapping Wing Mechanism Based on Bennett-Derived 6R Deployable Mechanisms

2014 ◽  
Author(s):  
Huang Hailin ◽  
Li Bing
Keyword(s):  
Flapping Wing ◽  
Geometric Design ◽  
Geometric Parameters ◽  
Degree Of Freedom ◽  
Single Degree Of Freedom ◽  
Flapping Motion ◽  
Single Degree ◽  
Revolute Joints ◽  
Air Vehicle ◽  
Deployable Mechanism

In this paper, we present the concept of designing flapping wing air vehicle by using the deployable mechanisms. A novel deployable 6R mechanism, with the deploying/folding motion of which similar to the flapping motion of the vehicle, is first designed by adding two revolute joints in the adjacent two links of the deployable Bennett linkage. The mobility of this mechanism is analyzed based on a coplanar 2-twist screw system. An intuitive projective approach for the geometric design of the 6R deployable mechanism is proposed by projecting the joint axes on the deployed plane. Then the geometric parameters of the deployable mechanism can be determined. By using another 4R deployable Bennett connector, the two 6R deployable wing mechanisms can be connected together such that the whole flapping wing mechanism has a single degree of freedom (DOF).

Design and Mobility Analysis of Large Deployable Mechanisms Based on Plane-Symmetric Bricard Linkage

2016 ◽  
Vol 139 (2) ◽  
Author(s):  
Xiaozhi Qi ◽  
Hailin Huang ◽  
Zhihuai Miao ◽  
Bing Li ◽  
Zongquan Deng
Keyword(s):  
Computer Aided Design ◽  
Closed Loop ◽  
Singularity Analysis ◽  
Degree Of Freedom ◽  
Plane Symmetric ◽  
Analysis And Design ◽  
Geometric Conditions ◽  
Deployable Mechanism ◽  
Vertical Bars ◽  
Aided Design

In this paper, a class of large deployable mechanisms constructed by plane-symmetric Bricard linkages is presented. The plane-symmetric Bricard linkage is a closed-loop overconstrained spatial mechanism composed of six hinge-jointed bars, which has one plane of symmetry during its deployment process. The kinematic analysis of the linkage is presented from the perspectives of geometric conditions, closure equations, and degree-of-freedom. The results illustrate that the linkage has one degree-of-freedom and can be deployed from the folded configuration to one rectangle plane. Therefore, the plane-symmetric Bricard linkage can be used as a basic deployable unit to construct larger deployable mechanisms. Four plane-symmetric Bricard linkages can be assembled into a quadrangular module by sharing the vertical bars of the adjacent units. The module is a multiloop deployable mechanism and has one degree-of-freedom. The singularity analysis of the module is developed, and two methods to avoid singularity are presented. A large deployable mast, deployable plane truss, and deployable ring are built with several plane-symmetric Bricard linkages. The deployment properties of the large deployable mechanisms are analyzed, and computer-aided design models for typical examples are built to illustrate their feasibility and validate the analysis and design methods.

scholarly journals Atmospheric Pressure Plasma Processing of an Optical Sinusoidal Grid

Micromachines ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 828 ◽  
Author(s):  
Duo Li ◽  
Na Li ◽  
Xing Su ◽  
Peng Ji ◽  
Bo Wang
Keyword(s):  
Surface Roughness ◽  
Atmospheric Pressure ◽  
Plasma Processing ◽  
Atmospheric Pressure Plasma ◽  
Degree Of Freedom ◽  
Generation Mechanism ◽  
Surface Generation ◽  
Pressure Plasma ◽  
Simulation And Experiment ◽  
Grid Surface

Sinusoidal grid with nanometric precision is adopted as a surface encoder to measure multiple degree-of-freedom motions. This paper proposes the atmospheric pressure plasma processing (APPP) technique to fabricate an optical sinusoidal grid surface. The characteristics of removal function and surface generation mechanism are firstly presented. Both simulation and experiment validate the effectiveness of APPP to fabricate a sinusoidal grid surface with nanometric precision. Post mechanical polishing experiments show that APPP features can be well maintained while the surface roughness is greatly reduced to meet the optical requirement.

Single-Vertex Multicrease Rigid Origami With Nonzero Thickness and Its Transformation Into Deployable Mechanisms

2017 ◽  
Vol 10 (1) ◽  
Author(s):  
Chenhan Guang ◽  
Yang Yang
Keyword(s):  
Computer Aided Design ◽  
Screw Theory ◽  
Kinematic Model ◽  
Degree Of Freedom ◽  
Single Vertex ◽  
Geometrical Characteristics ◽  
Computer Aided ◽  
Deployable Mechanism ◽  
Aided Design ◽  
Basic Configuration

The radial folding ratio of single-vertex multicrease rigid origami, from the folded configuration to the unfolded configuration, is satisfactory. In this study, we apply two approaches to add nonzero thickness for this kind of origami and identify different geometrical characteristics. Then, the model of the secondary folding origami, which can help to further decrease the folding ratio, is constructed. We apply the method of constraining the edges of the panels on prescribed planes to geometrically obtain the kinematic model. Based on the kinematic model and the screw theory, the nonzero thickness origami is transformed into the deployable mechanism with one degree-of-freedom (1DOF). Other similar mechanisms can be derived based on this basic configuration. The computer-aided design examples are presented to indicate the feasibility.

scholarly journals Synthesis and Design of a One Degree-of-Freedom Planar Deployable Mechanism With a Large Expansion Ratio

2016 ◽  
Vol 8 (2) ◽  
Author(s):  
David St-Onge ◽  
Clément Gosselin
Keyword(s):  
Expansion Ratio ◽  
Degree Of Freedom ◽  
Rigid Link ◽  
Large Expansion ◽  
Deployable Mechanism

This paper presents a new design of a deployable one degree-of-freedom (DOF) mechanism. Polygonal rigid-link designs are first investigated. Then, belt-driven links are considered in order to maximize the expansion ratio while avoiding flattened ill-conditioned parallelogram configurations. The planar basic shape of the proposed design is a triangle. Hence, virtually any planar or spatial surface can be created by assembling such faces. For architecture and telescopic applications, the cupola assembly is investigated. The advantages of this approach are discussed, and the scalability is demonstrated. Finally, a prototype is built for illustration purposes.

A Novel Deployable Mechanism With Two Decoupled Degrees of Freedom

2013 ◽  
Author(s):  
Shengnan Lu ◽  
Dimiter Zlatanov ◽  
Xilun Ding ◽  
Rezia Molfino ◽  
Matteo Zoppi
Keyword(s):  
Degrees Of Freedom ◽  
Degree Of Freedom ◽  
Deployable Structures ◽  
Two Component ◽  
Potential Applications ◽  
Magnification Ratio ◽  
Deployable Mechanism ◽  
The Relationship ◽  
Kinematic Properties ◽  
Kinematic Simulations

This paper presents a novel deployable mechanism. Unlike most deployable structures, which have one degree of freedom, the proposed device can be deployed and compacted independently in two directions. This widens the range of its potential applications, including flexible industrial fixtures and deployable tents. The mechanism’s basic deployable unit is assembled by combining a scissor linkage and a Sarrus linkage. The kinematic properties of the two component linkages and the combined unit are analyzed. The new deployable mechanism is obtained by linking the deployable units. The Mobility and kinematics are analyzed. The relationship between the degree of overconstraint and the number of deployable units is derived. The magnification ratio is calculated as a function of the geometry of the link and the number of deployable units. Finally, kinematic simulations are performed to validate the proposed design and analysis.

An Approach to Designing Deployable Mechanisms Based on Rigid Modified Origami Flashers

2018 ◽  
Vol 140 (8) ◽  
Author(s):  
Chenhan Guang ◽  
Yang Yang
Keyword(s):  
Geometric Model ◽  
Kinematic Model ◽  
Degree Of Freedom ◽  
Geometric Constraints ◽  
Curved Surface ◽  
Deployable Mechanism

Flasher, which has been used in space engineering, is a class of origami patterns. After modifying and introducing cuts for the flasher pattern, we add nonzero thickness to the flasher and taper its panels. We find that, if appropriately driven, the modified flasher can be used as the deployable mechanism, and even envelop the curved surface in its unfolded configuration. We establish a geometric model and a kinematic model for the mechanism. Then we propose a designing approach including folding design and driving method. The folding design, which ensures that the mechanism can be folded in the folded configuration, is based on geometric constraints. The driving method, which enables the multi-degree-of-freedom (DOF) mechanism to deploy in sequence with only one actuator, is based on underactuation. A prototype is built to validate this approach.

Approximating power for significance tests with one degree of freedom.

1997 ◽  
Vol 2 (2) ◽  
pp. 186-191 ◽  
Author(s):  
William P. Dunlap ◽  
Leann Myers
Keyword(s):  
Degree Of Freedom ◽  
Significance Tests

THE TEMPERATURE ROTATION OF THE EASY AXIS DIRECTION IN DyFe3

1979 ◽  
Vol 40 (C2) ◽  
pp. C2-193-C2-195 ◽  
Author(s):  
S. Japa ◽  
K. Krop ◽  
R. Radwanski ◽  
J. Wolinski
Keyword(s):  
Easy Axis ◽  
Axis Direction
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