Deployable Prismatic Structures With Rigid Origami Patterns

2016 ◽  
Vol 8 (3) ◽  
Author(s):  
Sicong Liu ◽  
Weilin Lv ◽  
Yan Chen ◽  
Guoxing Lu
Keyword(s):  
Closed Loop ◽  
Design Method ◽  
Kinematic Model ◽  
Deployable Structures ◽  
Engineering Applications ◽  
Single Degree Of Freedom ◽  
General Design ◽  
Plane Symmetric ◽  
Single Degree ◽  
Spherical Linkages

Rigid origami inspires new design technology in deployable structures with large deployable ratio due to the property of flat foldability. In this paper, we present a general kinematic model of rigid origami pattern and obtain a family of deployable prismatic structures. Basically, a four-crease vertex rigid origami pattern can be presented as a spherical 4R linkage, and the multivertex patterns are the assemblies of spherical linkages. Thus, this prismatic origami structure is modeled as a closed loop of spherical 4R linkages, which includes all the possible prismatic deployable structures consisting of quadrilateral facets and four-crease vertices. By solving the compatibility of the kinematic model, a new group of 2n-sided deployable prismatic structures with plane symmetric intersections is derived with multilayer, straight and curvy variations. The general design method for the 2n-sided multilayer deployable prismatic structures is proposed. All the deployable structures constructed with this method have single degree-of-freedom (DOF), can be deployed and folded without stretching or twisting the facets, and have the compactly flat-folded configuration, which makes it to have great potential in engineering applications.

Deployable Prismatic Structures With Origami Patterns

2014 ◽  
Author(s):  
Sicong Liu ◽  
Weilin Lv ◽  
Yan Chen ◽  
Guoxing Lu
Keyword(s):  
Design Method ◽  
Kinematic Model ◽  
The Other ◽  
Dihedral Angles ◽  
Geometric Condition ◽  
Compatibility Conditions ◽  
Deployable Structures ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
Geometric Compatibility

In order to find the general condition of the rigid origami pattern for the deployable prismatic structures, the kinematic model is proposed based on the mobile assemblies of spherical 4R linkages. The kinematic and geometric compatibility conditions of the mobile assemblies are derived. Two groups of 2n-side deployable prismatic structures are obtained. When n=2, one of them is with kite-shape intersection, while the other is with parallelgram. The variations of the unit are discussed. The straight and curvy multilayer prisms are built by changing the dihedral angles between the intersecting planes. The general design method for the 2n-side multilayer deployable prismatic structures is proposed with the geometric condition of the origami patterns. All the deployable structures constructed with this method can be deployed and folded along the central axis of the prisms with single degree of freedom, which makes the structures have wide engineering applications.

scholarly journals Research on a ø6m TBM Steel Arch Splicing Manipulator

2021 ◽  
Author(s):  
Yuanfu He ◽  
Yimin Xia ◽  
Zhen Xu ◽  
Jie Yao ◽  
Bo Ning ◽  
...  
Keyword(s):  
Large Volume ◽  
Closed Loop ◽  
Design Method ◽  
Dynamic Performance ◽  
Structural Stiffness ◽  
Input Constraints ◽  
Positioning Accuracy ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
Performance Indexes

Abstract As a challenging task, the robotic splicing of steel arch is required to realize the grasping and docking of steel arches in a limited space. The steel arches often have a mass of over 200kg and a length of over 4m. Due to the large volume and mass of steel arches and the high requirements for the positioning accuracy of splicing, it is difficult for the general manipulator to meet its flexibility and stiffness requirements. The single-degree-of-freedom(DOF) closed-loop mechanism has a simple and reliable structure. Adding it into the manipulator can effectively improve the dynamic performance and increase the structural stiffness. In this paper, a solution model of a single-DOF closed-loop planar mechanism is presented, and alternative kinematic pairs of the mechanism with different input constraints and output requirements are derived. Based on this model, a design method of steel arch splicing manipulator with single-DOF closed-loop grasping structure is proposed. All the optional basic configurations of the manipulator are deduced, and then the optimal configuration is obtained by using the performance indexes. A prototype of the steel arch splicing manipulator is manufactured, and the reliability of the manipulator is proved by experiments.

scholarly journals Symmetric waterbomb origami

2016 ◽  
Vol 472 (2190) ◽  
pp. 20150846 ◽  
Author(s):  
Yan Chen ◽  
Huijuan Feng ◽  
Jiayao Ma ◽  
Rui Peng ◽  
Zhong You
Keyword(s):  
Degrees Of Freedom ◽  
Degree Of Freedom ◽  
Solar Panels ◽  
Deployable Structures ◽  
Single Degree Of Freedom ◽  
Folding Process ◽  
Multiple Degrees Of Freedom ◽  
Single Degree ◽  
Flat Roofs ◽  
Additional Constraints

The traditional waterbomb origami, produced from a pattern consisting of a series of vertices where six creases meet, is one of the most widely used origami patterns. From a rigid origami viewpoint, it generally has multiple degrees of freedom, but when the pattern is folded symmetrically, the mobility reduces to one. This paper presents a thorough kinematic investigation on symmetric folding of the waterbomb pattern. It has been found that the pattern can have two folding paths under certain circumstance. Moreover, the pattern can be used to fold thick panels. Not only do the additional constraints imposed to fold the thick panels lead to single degree of freedom folding, but the folding process is also kinematically equivalent to the origami of zero-thickness sheets. The findings pave the way for the pattern being readily used to fold deployable structures ranging from flat roofs to large solar panels.

scholarly journals Using the Singularity Trace to Understand Linkage Motion Characteristics

2013 ◽  
Author(s):  
Lin Li ◽  
David H. Myszka ◽  
Andrew P. Murray ◽  
Charles W. Wampler
Keyword(s):  
Critical Points ◽  
Design Parameter ◽  
Closed Loop ◽  
Design Parameters ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
Net Zero ◽  
Motion Characteristics ◽  
Number Of Branches ◽  
Activation Sequence

This paper provides examples of a method used to analyze the motion characteristics of single-degree-of-freedom, closed-loop linkages under study a designated input angle and one or two design parameters. The method involves the construction of a singularity trace, which is a plot that reveals changes in the number of geometric inversions, singularities, and changes in the number of branches as a design parameter is varied. This paper applies the method to Watt II, Stephenson III and double butterfly linkages. For the latter two linkages, instances where the input angle is able to rotate more than one revolution between singularities have been identified. This characteristic demonstrates a net-zero, singularity free, activation sequence that places the mechanism into a different geometric inversion. Additional observations from the examples are given. Instances are shown where the singularity trace for the Watt II linkage includes multiple coincident projections of the singularity curve. Cases are shown where subtle changes to two design parameters of a Stephenson III linkage drastically alters the motion. Additionally, isolated critical points are found to exist for the double butterfly, where the linkage becomes a structure and looses the freedom to move.

Robust Control Design of a Single Degree-of-Freedom Magnetic Levitation System by Quantitative Feedback Theory

2012 ◽  
Author(s):  
Feng Tian ◽  
Mark Nagurka
Keyword(s):  
Robust Control ◽  
Magnetic Levitation ◽  
Design Method ◽  
Control Design ◽  
Open Loop ◽  
Quantitative Feedback Theory ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
Maglev System ◽  
Robust Control Design

A magnetic levitation (maglev) system is inherently nonlinear and open-loop unstable because of the nature of magnetic force. Most controllers for maglev systems are designed based on a nominal linearized model. System variations and uncertainties are not accommodated. The controllers are generally designed to satisfy gain and phase margin specifications, which may not guarantee a bound on the sensitivity. To address these issues, this paper proposes a robust control design method based on Quantitative Feedback Theory (QFT) applied to a single degree-of-freedom (DOF) maglev system. The controller is designed to successfully meet the stability requirement, robustness specifications, and bounds on the sensitivity. Experiments verify that the controller maintains stable levitation even with 100% load variation. Experiments prove that it guarantees the transient response design requirements even with 100% load change and 39% model uncertainties. The QFT control design method discussed in this paper can be applied to other open-loop unstable systems as well as systems with large uncertainties and variations to improve system robustness.

Branch Identification of Spherical Six-Bar Linkages

2016 ◽  
Author(s):  
Liangyi Nie ◽  
Jun Wang ◽  
Kwun-Lon Ting ◽  
Daxing Zhao ◽  
Quan Wang ◽  
...  
Keyword(s):  
Range Of Motion ◽  
Degree Of Freedom ◽  
Joint Rotation ◽  
Single Degree Of Freedom ◽  
Complex Issue ◽  
Single Degree ◽  
Identification Method ◽  
Spatial Linkages ◽  
Spherical Linkages

Branch (assembly mode or circuit) identification is a way to assure motion continuity among discrete linkage positions. Branch problem is the most fundamental, pivotal, and complex issue among the mobility problems that may also include sub-branch (singularity-free) identification, range of motion, and order of motion. Branch and mobility complexity increases greatly in spherical or spatial linkages. This paper presents the branch identification method suitable for automated motion continuity rectification of a single degree-of-freedom of spherical linkages. Using discriminant method and the concept of joint rotation space (JRS), the branch of a spherical linkage can be easily identified. The proposed method is general and conceptually straightforward. It can be applied for all linkage inversions. Examples are employed to illustrate the proposed method.

Handwriting: A Perceptual-Motor Disturbance in Children with Myelomeningocele

1990 ◽  
Vol 10 (1) ◽  
pp. 12-26 ◽  
Author(s):  
Jenny Ziviani ◽  
Alan Hayes ◽  
David Chant
Keyword(s):  
Skill Acquisition ◽  
Closed Loop ◽  
Statistical Significance ◽  
Regression Analyses ◽  
Single Degree Of Freedom ◽  
Motor Disturbance ◽  
Motor Skill Acquisition ◽  
Single Degree ◽  
Scholastic Aptitude ◽  
Effect Of Age

An explanation for the handwriting difficulties experienced by children with spina bifida myelomeningocele was sought within the framework of a closed-loop theory of motor skill acquisition. The handwriting performance of 34 children (16 boys and 18 girls) aged 6.16 to 13.42 years was detailed with available norms. Regression analyses were then performed for the five handwriting components of speed, alignment, letter formation, spacing, and size. The regressions for speed, alignment, and letter formation reached statistical significance. For speed, age provided the greatest explanation of performance (R2 = .62, p = .008). Alignment was explained substantially by age, handedness, scholastic aptitude, and kinesthesia (R2 = .55, p = .03). Letter formation was determined primarily by age and kinesthesia (R2 .71, p = .001,). The overall regression was not significant for spacing (R2 = .39, p = .30), or size (R2 = .35, p = .43), although a significant single degree of freedom was detected for the effect of age. These findings are discussed in terms of skill acquisition theory.

Single-Degree-of-Freedom Rigidly Foldable Origami Flashers

2015 ◽  
Author(s):  
Robert J. Lang ◽  
Spencer Magleby ◽  
Larry Howell
Keyword(s):  
Degree Of Freedom ◽  
Deployable Structures ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
Revolute Joints

We present the design for a family of deployable structures based on the origami flasher that are rigidly foldable, i.e., foldable with revolute joints at the hinges and planar rigid faces, and that exhibit a single degree of freedom in their motion. These structures may be used to realize highly compact deployable mechanisms.

A general design method for closed-loop solar energy systems

Solar Energy ◽  
1979 ◽  
Vol 22 (3) ◽  
pp. 269-282 ◽  
Author(s):  
S.A. Klein ◽  
W.A. Beckman
Keyword(s):  
Solar Energy ◽  
Closed Loop ◽  
Design Method ◽  
Energy Systems ◽  
General Design

scholarly journals A Design System for Six-Bar Linkages Integrated With a Solid Modeler

2015 ◽  
Vol 15 (4) ◽  
Author(s):  
Kaustubh H. Sonawale ◽  
J. Michael McCarthy
Keyword(s):  
Degree Of Freedom ◽  
Design System ◽  
Solid Model ◽  
Design Algorithm ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
Serial Chain ◽  
Tolerance Zones ◽  
Spherical Linkages ◽  
Solid Modeler

This paper presents a design system for planar and spherical six-bar linkages, which is integrated with a solid modeler. The user specifies a backbone 3R chain in five task configurations in the sketch mode of the solid modeler and executes the design system. Two RR constraints are computed, which constrain the 3R chain to a single degree-of-freedom six-bar linkage. There are six ways that these constraints can be added to the 3R serial chain to yield as many as 63 different linkages in case of planar six-bar linkages and 165 in case of spherical six-bar linkages. The performance of each candidate is analyzed, and those that meet the required task are presented to the designer for selection. The design algorithm is run iteratively with random variations applied to the task configurations within user-specified tolerance zones, to increase the number of candidate designs. The output is a solid model of the six-bar linkage. Examples are presented, which demonstrate the effectiveness of this strategy for both planar and spherical linkages.

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