Approximation of Cylindrical Surfaces With Deployable Bennett Networks

2016 ◽  
Author(s):  
Shengnan Lu ◽  
Dimiter Zlatanov ◽  
Xilun Ding
Keyword(s):  
Modeling And Simulation ◽  
Case Studies ◽  
Cylindrical Surface ◽  
Kinematic Analysis ◽  
Geometric Parameters ◽  
Degree Of Freedom ◽  
Curved Surfaces ◽  
Deployable Structures ◽  
Elliptical Cylinders ◽  
Insight Into

This paper presents a one-degree-of-freedom network of Bennett linkages which can be deployed to approximate a cylindrical surface. The geometry of the unit mechanism is parameterized and its position kinematics is solved. The influence of the geometric parameters on the deployed shape is examined. Further kinematic analysis isolates those Bennett geometries for which a cylindrical network can be constructed. The procedure for connecting the unit mechanisms in a deployable cylinder is described in detail and used to gain insight into, and formulate some general guidelines for, the design of linkage networks which unfold as curved surfaces. Case studies of deployable structures in the shape of circular and elliptical cylinders are presented. Modeling and simulation validate the proposed approach.

Approximation of Cylindrical Surfaces With Deployable Bennett Networks

2017 ◽  
Vol 9 (2) ◽  
Author(s):  
Shengnan Lu ◽  
Dimiter Zlatanov ◽  
Xilun Ding
Keyword(s):  
Modeling And Simulation ◽  
Case Studies ◽  
Cylindrical Surface ◽  
Kinematic Analysis ◽  
Geometric Parameters ◽  
Degree Of Freedom ◽  
Curved Surfaces ◽  
Deployable Structures ◽  
Elliptical Cylinders ◽  
Insight Into

This paper presents a one-degree-of-freedom network of Bennett linkages which can be deployed to approximate a cylindrical surface. The geometry of the unit mechanism is parameterized and its position kinematics is solved. The influence of the geometric parameters on the deployed shape is examined. Further kinematic analysis isolates those Bennett geometries for which a cylindrical network can be constructed. The procedure for connecting the unit mechanisms in a deployable cylinder is described in detail and used to gain insight into, and formulate some general guidelines for, the design of linkage networks which unfold as curved surfaces. Case studies of deployable structures in the shape of circular and elliptical cylinders are presented. Modeling and simulation validate the proposed approach.

scholarly journals A Network of Type III Bricard Linkages

2015 ◽  
Author(s):  
Shengnan Lu ◽  
Dimiter Zlatanov ◽  
Xilun Ding ◽  
Matteo Zoppi ◽  
Simon D. Guest
Keyword(s):  
Case Studies ◽  
Geometric Parameters ◽  
Degree Of Freedom ◽  
Regular Hexagon ◽  
Analysis And Design ◽  
Type Iii ◽  
The Third ◽  
Planar Shape ◽  
Planar Shapes ◽  
Parameter Values

Among Bricard’s overconstrained 6R linkages, the third type has two collapsed configurations, where all joint axes are coplanar. The paper presents a one-degree-of-freedom network of such linkages. Using the two coplanar states of the constituent Bricard units, the network is able to cover a large surface with a specific outline when deployed, and can be folded compactly into a stack of much smaller planar shapes. Five geometric parameters describing each type III Bricard mechanism are introduced. Their influence on the outline of one collapsed configuration is discussed and inverse calculation to obtain the parameter values yielding a desired planar shape is performed. The network is built by linking the units, either using scissor linkage elements, if the thickness of the panels can be ignored, or with hinged parallelograms, for a thicker material. Two case studies, in which the Bricard network deploys as a rectangle and a regular hexagon, respectively, are presented, validating the analysis and design methods.

scholarly journals A Network of Type III Bricard Linkages

2018 ◽  
Vol 11 (1) ◽  
Author(s):  
Shengnan Lu ◽  
Dimiter Zlatanov ◽  
Xilun Ding ◽  
Matteo Zoppi ◽  
Simon D. Guest
Keyword(s):  
Case Studies ◽  
Geometric Parameters ◽  
Degree Of Freedom ◽  
Regular Hexagon ◽  
Analysis And Design ◽  
Type Iii ◽  
The Third ◽  
Planar Shape ◽  
Planar Shapes ◽  
Parameter Values

Among Bricard's overconstrained 6R linkages, the third type has two collapsed configurations, where all joint axes are coplanar. This paper presents a one-degree-of-freedom network of such linkages. Using the two coplanar states of the constituent Bricard units, the network is able to cover a large surface with a specific outline when deployed and can be folded compactly into a stack of much smaller planar shapes. Five geometric parameters describing each type III Bricard mechanism are introduced. Their influence on the outline of one collapsed configuration is discussed and inverse calculation to obtain the parameter values yielding a desired planar shape is performed. The network is built by linking the units, either using scissor linkage elements, if the thickness of the panels can be ignored, or with hinged parallelograms, for a thicker material. Two case studies, in which the Bricard network deploys as a rectangle and a regular hexagon, respectively, are presented, validating the analysis and design methods.

A Mobile Bennett Network Constructed with Identical Square Panels

2021 ◽  
pp. 1-23
Author(s):  
Fufu Yang ◽  
Yuan Gao ◽  
Shuailong Lu ◽  
Kunjing Chen
Keyword(s):  
Mobile Networks ◽  
Design Parameter ◽  
Degree Of Freedom ◽  
Deployable Structures ◽  
Geometric Conditions ◽  
Application Potential

Abstract Mobile networks, constructed with simple linkages by tessellation, have great application potential in engineering as they could change their shapes according to the need of working state by one degree of freedom (DOF). However, the existing one-DOF networks are always composed of bar-like links, and cooperated membranes should be designed and fabricated additionally, which makes the design and the realization more complicated. This paper is to construct a one-DOF network of Bennett linkages with identical square panels. Geometric conditions to construct the network are derived by investigating the kinematic compatibility, kinematics is carried out to show the relationships among all Bennett linkages, and the discussion on the design parameter shows the extensibility and the deploying performance, which is validated by two physical prototypes. This work initials the construction of mobile networks with identical polygon-like links, which will simplify the fabrication and realization of deployable structures.

Kinematic and Workspace Modelling of a 6-PUS Parallel Mechanism

2018 ◽  
Author(s):  
Jérôme Landuré ◽  
Clément Gosselin
Keyword(s):  
Kinematic Analysis ◽  
Parallel Mechanism ◽  
Inverse Kinematic ◽  
Degree Of Freedom ◽  
Accurate Description ◽  
Transmission Ratio ◽  
Inverse Kinematic Problem ◽  
Jacobian Matrices ◽  
Six Degree Of Freedom

This article presents the kinematic analysis of a six-degree-of-freedom six-legged parallel mechanism of the 6-PUS architecture. The inverse kinematic problem is recalled and the Jacobian matrices are derived. Then, an algorithm for the geometric determination of the workspace is presented, which yields a very fast and accurate description of the workspace of the mechanism. Singular boundaries and a transmission ratio index are then introduced and studied for a set of architectural parameters. The proposed analysis yields conceptual architectures whose properties can be adjusted to fit given applications.

Technology-Enhanced Learning Standard through Integration of Modeling and Simulation into Engineering Study Programs

2012 ◽  
pp. 157-177
Author(s):  
Dietmar P. F. Moeller ◽  
Hamid Vakilzadian
Keyword(s):  
Modeling And Simulation ◽  
Electrical Engineering ◽  
Technology Enhanced Learning ◽  
Engineering System ◽  
Engineering Study ◽  
Study Programs ◽  
And Performance ◽  
University Of Nebraska Lincoln ◽  
Enhanced Learning ◽  
Insight Into

Introducing a technology-enhanced learning standard in engineering study programs requires a deeper insight into and understanding of the complexity and dynamics of today’s engineering systems. This can be achieved by embedding Modeling and Simulation (M&S) within engineering study programs to stimulate educational innovations in undergraduate engineering curricula, such as electrical engineering. An example of this is in the process of being implemented in the Department of Electrical Engineering (EE) at the University of Nebraska – Lincoln (UNL). The need for such programs is evident by recent recommendations from the White House, the U.S. Congress, and the National Science Foundation, all of which stress that M&S is one of the key enabling technologies of the 21st century and is critical to U.S. competitiveness. Various models of a dynamic engineering system can be developed at different levels of detail in accordance with the recommended technical specifications to gain better insight into the behavior, stability, and performance of a system. The functionality of a real engineering system can be tested virtually by changing the structure, parameters, and inputs and outputs of the model to accurately predict the response of the system under various operating conditions. In order to educate a skilled workforce capable of meeting the country’s critical needs, the educational requirements for undergraduates in an M&S-based EE program have to be developed. Such a program needs to meet the accreditation requirements set by the Accreditation Board for Engineering and Technology Inc. (ABET).

Issues for the Evaluation of Ambient Displays

2011 ◽  
pp. 147-156
Author(s):  
Xiaobin Shen ◽  
Andrew Vande Moere ◽  
Peter Eades ◽  
Seok-Hee Hong
Keyword(s):  
Case Studies ◽  
Quantitative Measurement ◽  
Direct Proportion ◽  
User Interest ◽  
Information Displays ◽  
Ambient Displays ◽  
Evaluation Time ◽  
The Relationship ◽  
Insight Into ◽  
Time Issue

This article is motivated by two evaluation case studies of ambient information displays. Firstly, an intrusive evaluation of a display called MoneyColor concentrates on the relationship between “distraction” and “comprehension”. This revealed that the comprehension is in direct proportion to display-distraction, but there is no clear relationship between comprehension and self-interruption. Secondly, a non-intrusive evaluation of a display called Fisherman described a quantitative measurement of user “interest” and applied this measurement to investigate “evaluation time” issue. These experiments give some insight into number of issues in evaluation of ambient displays.

Playing (Safely) with Fire

2021 ◽  
pp. 218-234
Author(s):  
Mary Angela Bock
Keyword(s):  
Criminal Justice ◽  
Public Sphere ◽  
Criminal Justice System ◽  
Case Studies ◽  
Social Actors ◽  
The Public ◽  
Human Capability ◽  
The Public Sphere ◽  
Insight Into ◽  
The Way

This chapter reviews the project’s argument, that social actors struggle over the construction of visual messages in embodied and discursive ways. Digitization has vastly expanded the encoding capabilities of everyday citizens, allowing them to render their expression of democratic voice visible, even as the ethical rules for visual expression are inchoate. The project’s case studies demonstrate the way grounded practices produce representations that support the authority of the criminal justice system, and together they invite three theoretical discussions: (1) on the way visual journalism’s physicality increases its reliance on those in power, (2) on the importance of image indexicality as a discursive affordance in the public sphere, and (3) on the digital public sphere as visual, and participation in this visual public sphere must be considered as an essential human capability. As a whole, the project offers insight into the construction of the criminal justice system’s literal and metaphorical image.

Emerging Research and Trends

2021 ◽  
pp. 367-399
Keyword(s):  
Case Studies ◽  
Model Development ◽  
Business Partnerships ◽  
Prior Work ◽  
Scholarly Journals ◽  
The Past ◽  
Insight Into

This chapter serves as a review of the emerging research related to academy-business partnerships by examining dissertations, masters theses, and some reports in the past few decades. Given that most research from dissertations is not published in scholarly journals nor books, this review provides insight into the exploration of relevant topics. An attempt has been made to cluster prior work into related groupings so that a portrait of existing research can emerge. The sparse studies included in this review yielded thin clusters of research on model development, fiscal adaptations, and idiosyncratic case studies. The largest grouping of somewhat fragmented research is clustered around examinations of individuals within the partnerships and partnership-making; this latter grouping explores the various actors from the business or academy sides of such partnerships. A summary of a NACRO survey is also included to provide research-based perspectives of actual academy-business partnerships.

Transitional Labor: Undocumented Workers in the Los Angeles Automobile Industry

1983 ◽  
Vol 17 (4) ◽  
pp. 570-596 ◽  
Author(s):  
Rebecca Morales
Keyword(s):  
Labor Market ◽  
Los Angeles ◽  
Labor Force ◽  
Case Studies ◽  
Automobile Industry ◽  
Industrial Change ◽  
Undocumented Workers ◽  
Current Period ◽  
Insight Into

This article examines the employment of undocumented workers by Los Angeles manufacturers of automobile parts. It suggests that this is part of a broad trend towards primary labor market erosion. The labor force is termed transitional because it is seen as facilitating firms during the current period of industrial change. Insight into the role of these workers is derived from eight case studies representing 926 workers. Regressions on the determinants of wages and the percent undocumented in the workplace are developed from 21 firms and 2,321 workers.

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