An Application of a Digital Twin to Robotic System Design for an Unstructured Environment

2019 ◽  
Author(s):  
Matthew Q. Marshall ◽  
Cameron Redovian
Keyword(s):  
Life Stage ◽  
Robotic System ◽  
Ease Of Use ◽  
Design Decision ◽  
Feed System ◽  
Design Decisions ◽  
Digital Twin ◽  
Simulation Based ◽  
Unstructured Environment ◽  
Mobile Base

Abstract An experimentable digital twin is created to aid in a design decision (beginning of life stage) for a robotic system. This product is meant to automate a material-feed system. The robot comprises a six-axis manipulator mounted on a mobile base. Due to variability in the dimensions of the material-feed system and positioning error of the mobile base, the material-placement routine is considered to take place in an unstructured environment. Working therein requires exteroceptive sensors, in this instance taking the form of computer vision. Data from this subsystem are used to match the geometry of the digital twin to the physical environment. This close correspondence between physical and virtual embodiments allows for significant design decisions to be reached from simulated experiments. In this case, two motion-planning approaches are compared and it is determined that the costs associated with implementing the dynamic one in the lab for testing are merited by its ease of use and reliability, since simulation-based control employs all current information.

A novel recursive formulation for dynamic modeling and trajectory tracking control of multi-rigid-link robotic manipulators mounted on a mobile platform

2020 ◽  
pp. 095965182097390
Author(s):  
AM Shafei ◽  
H Mirzaeinejad
Keyword(s):  
Dynamic Modeling ◽  
Predictive Control ◽  
Trajectory Tracking ◽  
Tracking Control ◽  
Robotic System ◽  
Mobile Platform ◽  
Reference Trajectory ◽  
Trajectory Tracking Control ◽  
Recursive Formulation ◽  
Mobile Base

This article establishes an innovative and general approach for the dynamic modeling and trajectory tracking control of a serial robotic manipulator with n-rigid links connected by revolute joints and mounted on an autonomous wheeled mobile platform. To this end, first the Gibbs–Appell formulation is applied to derive the motion equations of the mentioned robotic system in closed form. In fact, by using this dynamic method, one can eliminate the disadvantage of dealing with the Lagrange Multipliers that arise from nonholonomic system constraints. Then, based on a predictive control approach, a general recursive formulation is used to analytically obtain the kinematic control laws. This multivariable kinematic controller determines the desired values of linear and angular velocities for the mobile base and manipulator arms by minimizing a point-wise quadratic cost function for the predicted tracking errors between the current position and the reference trajectory of the system. Again, by relying on predictive control, the dynamic model of the system in state space form and the desired velocities obtained from the kinematic controller are exploited to find proper input control torques for the robotic mechanism in the presence of model uncertainties. Finally, a computer simulation is performed to demonstrate that the proposed algorithm can dynamically model and simultaneously control the trajectories of the mobile base and the end-effector of such a complicated and high-degree-of-freedom robotic system.

scholarly journals ESTUDIO DEMOGRÁFICO DE Emilia sonchifolia (ASTERACEAE) EN UNA FINCA CAFETERA DE ARMENIA, QUINDÍO, COLOMBIA

2014 ◽  
Vol 20 (2) ◽  
Author(s):  
Irene Duarte Gandica ◽  
Maryam Chaib de Mares ◽  
David Andrés Luna ◽  
Oscar Alexander Aguirre-Obando ◽  
Rosa María Méndez Parra
Keyword(s):  
Logistic Model ◽  
Research Study ◽  
Life Stage ◽  
Coffee Plantation ◽  
Simulation Based ◽  
Coffee Farm ◽  
Number Of Leaves ◽  
Potential Strategy ◽  
Study Sites ◽  
Number Of Individuals

<p>Se realizó un estudio con el fin de determinar la estructura demográfica de <em>Emilia sonchifolia </em>(L.) DC<em> </em>en una finca cafetera del Municipio de Armenia, Quindío, Colombia, donde se recolectaron datos durante 4 semanas, en tres sitios: exterior, borde e interior del cultivo. Usando parámetros calculados a partir de los datos de campo, se construyó un modelo logístico para describir el comportamiento poblacional en el tiempo. Se encontraron diferencias significativas en las variables: número de individuos por estado etario en el tiempo, porcentaje de mortalidad, tiempo de cambio del estado plántula a juvenil y de juvenil a adulto, número de hojas y de ramas; no se encontraron diferencias significativas en la densidad poblacional, número de inflorescencias e infrutescencias en los sitios de estudio. En general, se puede atribuir este comportamiento a la estrategia de reproducción <em>r</em> que sigue <em>E. sonchifolia</em>. Finalmente, las simulaciones hechas a partir del modelo logístico sugieren que la especie tiende a desaparecer si alguno de los estados etarios no está presente inicialmente; así, una alternativa plausible para el control sería su eliminación en el estado juvenil. Los resultados ofrecen alternativas con respecto al manejo de<em> </em>poblaciones de arvenses.</p><p><strong>ABSTRACT</strong></p><p>A research study was conducted to determine the demographic structure of <em>Emilia sonchifolia</em> L. in a coffee plantation in Armenia, Quindío, Colombia. Data were collected over a period of four weeks on three sites: inside, at the border and outside a coffee farm. A logistic population model was built to describe the population behavior of <em>E. sonchifol</em><em>ia </em>over time. Statiscally significant differences were found between: number of individuals per life stage in time, mortality rate, transition time from seedling to juvenile and from juvenile to adult; and number of leaves and branches. There was no evidence for statistically significant differences in population density or in number of inflorescences and fruits between study sites. In general, the observed behavior may be attributed to the <em>r</em> strategy used by this species. Finally, our results suggest the survival of the species is conditioned by the presence of all life stages at the beginning of each simulation based on the logistic model; so, a potential strategy for its controlling would require the removal during the juvenile stage. The considerations offer alternatives regarding weed population management.  </p>

Enhancing Critical Thinking Through “Independent Design Decision Making” in the Studio

2006 ◽  
Vol 31 (3) ◽  
pp. 33-42
Author(s):  
Mallika Bose ◽  
Eliza Pennypacker ◽  
Thomas Yahner
Keyword(s):  
Decision Making ◽  
Critical Thinking ◽  
Comparative Study ◽  
Landscape Architecture ◽  
Teaching Method ◽  
Design Studio ◽  
Design Decision ◽  
Design Decisions ◽  
Independent Design ◽  
Design Ideas

A group of faculty at Penn State's Department of Landscape Architecture observed that the traditional master/apprentice model of studio instruction fosters greater student dependence on faculty for decision-making guidance than the faculty considers desirable. They contend that this traditional model promotes a studio dynamic that encourages students to look to the professor for design ideas and wait for faculty approval before making design decisions. The faculty considered this decision-making dependency to be in conflict with the need for students to develop the critical-thinking skills required to address the complex and ill-structured problems that are common in architecture and landscape architecture. In response to their concern this faculty team developed a studio teaching method they termed “independent design decision-making.” They speculated that by transferring the responsibility for design decisions from professor to the student, students could improve their critical thinking and gain confidence in design decision-making. The faculty conceived a set of strategies to implement in a 3rd year team-taught site planning and design studio that presents a range of complex design issues and scales. In collaboration with Penn State's Schreyer Institute for Teaching Excellence, the faculty researchers developed a 2-year comparative study to test this new teaching method in the same design studio with two consecutive student groups-evaluating the strategies implemented in the first year, refining methods, then applying and re-evaluating the results in the next year's class. These new strategies included ways students receive information to inspire their designs (“input strategies”) and ways to receive critique on their design ideas (“feedback strategies”). Two evaluation instruments were chosen to assess this method of studio teaching: 1) the Group Embedded Figures Test (GEFT), and 2) Student Assessment of Learning Gains (SALG). This paper presents this teaching/learning method and reports on the results of the comparative study.

Metrics development and modelling the mixed reality and digital twin adoption in the context of Industry 4.0

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Samad M.E. Sepasgozar ◽  
Mohsen Ghobadi ◽  
Sara Shirowzhan ◽  
David J. Edwards ◽  
Elham Delzendeh
Keyword(s):  
Technology Acceptance ◽  
Mixed Reality ◽  
Ease Of Use ◽  
Perceived Usefulness ◽  
Future Research ◽  
Key Factors ◽  
Content Type ◽  
Factors Affecting ◽  
Digital Twin ◽  
Acceptance Model

PurposeThis paper aims to examine the current technology acceptance model (TAM) in the field of mixed reality and digital twin (MRDT) and identify key factors affecting users' intentions to use MRDT. The factors are used as a set of key metrics for proposing a predictive model for virtual, augmented and mixed reality (MR) acceptance by users. This model is called the extended TAM for MRDT adoption in the architecture, engineering, construction and operations (AECO) industry.Design/methodology/approachAn interpretivist philosophical lens was adopted to conduct an inductive systematic and bibliographical analysis of secondary data contained within published journal articles that focused upon MRDT acceptance modelling. The preferred reporting items for systematic reviews and meta-analyses (PRISMA) approach to meta-analysis were adopted to ensure all key investigations were included in the final database set. Quantity indicators such as path coefficients, factor ranking, Cronbach’s alpha (a) and chi-square (b) test, coupled with content analysis, were used for examining the database constructed. The database included journal papers from 2010 to 2020.FindingsThe extant literature revealed that the most commonly used constructs of the MRDT–TAM included: subjective norm; social influence; perceived ease of use (PEOU); perceived security; perceived enjoyment; satisfaction; perceived usefulness (PU); attitude; and behavioural intention (BI). Using these identified constructs, the general extended TAM for MRDT in the AECO industry is developed. Other important factors such as “perceived immersion” could be added to the obtained model.Research limitations/implicationsThe decision to utilise a new technology is difficult and high risk in the construction project context, due to the complexity of MRDT technologies and dynamic construction environment. The outcome of the decision may affect employee performance, project productivity and on-site safety. The extended acceptance model offers a set of factors that assist managers or practitioners in making effective decisions for utilising any type of MRDT technology.Practical implicationsSeveral constraints are apparent due to the limited investigation of MRDT evaluation matrices and empirical studies. For example, the research only covers technologies which have been reported in the literature, relating to virtual reality (VR), augmented reality (AR), MR, DT and sensors, so newer technologies may not be included. Moreover, the review process could span a longer time period and thus embrace a fuller spectrum of technology development in these different areas.Originality/valueThe research provides a theoretical model for measuring and evaluating MRDT acceptance at the individual level in the AECO context and signposts future research related to MRDT adoption in the AECO industry, as well as providing managerial guidance for progressive AECO professionals who seek to expand their use of MRDT in the Fourth Industrial Revolution (4IR). A set of key factors affecting MRDT acceptance is identified which will help innovators to improve their technology to achieve a wider acceptance.

Robust Design of Coupled Engineered Systems

2021 ◽  
Author(s):  
Gehendra Sharma ◽  
Janet K. Allen ◽  
Farrokh Mistree
Keyword(s):  
Robust Design ◽  
Solution Space ◽  
Strong Interactions ◽  
Design Decision ◽  
Design Decisions ◽  
Robust Solution ◽  
Vertical Coupling ◽  
Strength Of Interaction ◽  
Robust Decisions ◽  
Engineered Systems

Abstract Coupled Engineered Systems can be characterized by the inherent interactions among design decisions. These interactions define the influence that one design decision exerts over another and require appropriate method to model such interactions. Robust design enables designers to design a product or process that is relatively insensitive to uncertainties. Hence, robust design of coupled engineered systems enables designers to, (i) design engineered systems while accounting for interaction among design decisions and (ii) identifying design decisions that are relatively insensitive to uncertainties. In this paper, an appropriate method to model interactions and identify robust solution is presented. The interacting decisions are categorized into concurrent and hierarchical decisions and are respectively modeled with horizontal and vertical coupling. Based on the strength of interaction between these decisions, two types of interactions are defined, weak and strong interactions. To enable robust decisions in a coupled engineered systems, robustness metrics are defined and included as goals/constraints. The metrics considered in this work are to explore the solution space and manage uncertainty by considering the design of robust systems. The method has been tested on three design examples, that are, (i) design of a fender, (ii) design of a gearbox and (iii) design of a composite structure.

The power of visualization choices: Different images of patterns in space

2020 ◽  
Author(s):  
Britta Ricker ◽  
Menno-Jan Kraak ◽  
Yuri Engelhardt
Keyword(s):  
United Nations ◽  
Gender Inequality ◽  
Design Decision ◽  
Inequality Index ◽  
Design Decisions ◽  
The Public ◽  
Decision Points ◽  
The World ◽  
The United Nations ◽  
Made In

Maps are representations of the world. They offer summaries or simplifications of data that are collected, attempt to reveal unknowns, to simplify and communicate complex spatial phenomena. Numerous decisions are made in the process of creating a map. Seemingly inconsequential variations of cartographic design decisions offer many ways to illustrate this process. We use an open dataset related to the United Nations Gender Inequality Index to demonstrate design decision points and their output. As governments are increasingly making data open to the public, and map-making tools and software are now more accessible online, these considerations are important both for those making and reading maps online.

scholarly journals Use of Equivalent Loss Models Under Section 316(b) of the Clean Water Act

2002 ◽  
Vol 2 ◽  
pp. 254-270
Author(s):  
William Dey
Keyword(s):  
Screening Tool ◽  
Life Stage ◽  
Ease Of Use ◽  
Environmental Benefits ◽  
Assessment Process ◽  
Clean Water ◽  
Data Input ◽  
Common Currency ◽  
Loss Models

Equivalent loss models encompass a variety of life table-based approaches that can be used to convert age- and life stage-specific estimates of entrainment and impingement loss to a common, easily understood currency. This common currency can be expressed in terms of numbers of individuals, yield to the fishery, or biomass to the ecosystem. These models have at least two key uses in the Section 316(b) assessment process: screening for adverse environmental impact (AEI) and determination of environmental benefits associated with intake alternatives. This paper reviews the various forms of equivalent loss models, their data input requirements, and their assumptions and limitations. In addition, it describes how these models can be used as a second-level screening tool as part of the assessment of the potential for AEI. Given their relative simplicity and ease of use, equivalent loss models should prove to be an important tool in the arsenal of impact assessment methods for Section 316(b).

scholarly journals The Agile Robotics for Industrial Automation Competition

AI Magazine ◽  
2018 ◽  
Vol 39 (4) ◽  
pp. 73-76 ◽  
Author(s):  
William Harrison ◽  
Anthony Downs ◽  
Craig Schlenoff
Keyword(s):  
Dynamic Environment ◽  
Robotic System ◽  
System Control ◽  
Industrial Automation ◽  
Control Code ◽  
Simulation Based

The Agile Robotics for Industrial Automation Competition (ARIAC) is an annual simulation-based competition initiated in 2017. The competition challenges teams to design industrial robotic system control code to function in a dynamic environment. Each team’s system is faced with challenges such as dropped parts, and must address these challenges and continue to function without operator intervention.

scholarly journals Simulation-based Analysis of the Interaction of a Physical and a Digital Twin in a Cyber-Physical Production System

2019 ◽  
Vol 52 (13) ◽  
pp. 1331-1336 ◽  
Author(s):  
Abderrahim Ait-Alla ◽  
Markus Kreutz ◽  
Daniel Rippel ◽  
Michael Lütjen ◽  
Michael Freitag
Keyword(s):  
Production System ◽  
Digital Twin ◽  
Simulation Based
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