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.

scholarly journals A method for robust design in a coupled decision environment

2021 ◽  
Vol 7 ◽  
Author(s):  
Gehendra Sharma ◽  
Janet K. Allen ◽  
Farrokh Mistree
Keyword(s):  
Robust Design ◽  
Type I ◽  
Type Ii ◽  
Design Decisions ◽  
Design Variables ◽  
Robust Decisions ◽  
Decision Environment ◽  
Function Relationship ◽  
Noise Factors ◽  
Selection Of

Abstract The design of a connected engineered system requires numerous design decisions that influence one another. In a connected system that comprises numerous interacting decisions involving concurrency and hierarchy, accounting for interactions while also managing uncertainties, it is imperative to make robust decisions. In this article, we present a method for robust design using coupled decisions to identify design decisions that are relatively insensitive to uncertainties. To account for the influence among decisions, design decisions are modelled as coupled decisions. They are defined using three criteria: the types of decisions, the strength of interactions and the decision levels. In order to make robust decisions, robust design methods are classified based on sources of uncertainty, namely, Type I (noise factors), Type II (design variables) and Type III (function relationship between design variables and responses). The design of a one-stage reduction gearbox is used as a demonstration example. To illustrate the proposed method for robust design using coupled decisions, we present the simultaneous selection of gear material and gearbox geometry in a coupled decision environment while managing the uncertainties involved in designing gearboxes.

scholarly journals Early Robust Design—Its Effect on Parameter and Tolerance Optimization

2021 ◽  
Vol 11 (20) ◽  
pp. 9407
Author(s):  
Stefan Goetz ◽  
Martin Roth ◽  
Benjamin Schleich
Keyword(s):  
Product Development ◽  
Robust Design ◽  
Product Development Process ◽  
Design Parameters ◽  
Concept Design ◽  
Design Decisions ◽  
Dynamic Markets ◽  
Tolerance Optimization ◽  
Qualitative Approaches ◽  
Design Activities

The development of complex products with high quality in dynamic markets requires appropriate robust design and tolerancing workflows supporting the entire product development process. Despite the large number of methods and tools available for designers and tolerance engineers, there are hardly any consistent approaches that are applicable throughout all development stages. This is mainly due to the break between the primarily qualitative approaches for the concept stage and the quantitative parameter and tolerance design activities in subsequent stages. Motivated by this, this paper bridges the gap between these two different views by contrasting the used terminology and methods. Moreover, it studies the effects of early robust design decisions with a focus on Suh’s Axiomatic Design axioms on later parameter and tolerance optimization. Since most robust design activities in concept design can be ascribed to these axioms, this allows reliable statements about the specific benefits of early robust design decisions on the entire process considering variation in product development for the first time. The presented effects on the optimization of nominal design parameters and their tolerance values are shown by means of a case study based on ski bindings.

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.

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.

An Inverse, Decision-Based Design Method for Robust Concept Exploration

2020 ◽  
Vol 142 (8) ◽  
Author(s):  
Anand Balu Nellippallil ◽  
Pranav Mohan ◽  
Janet K. Allen ◽  
Farrokh Mistree
Keyword(s):  
Analytical Model ◽  
Robust Design ◽  
Hot Rolling ◽  
Design Method ◽  
Inverse Design ◽  
Cooling Process ◽  
Robust Solution ◽  
Robust Solutions ◽  
Process Chains ◽  
Inverse Design Method

Abstract In this paper, we extend our previous work on a goal-oriented inverse design method to carry out inverse robust design by managing the uncertainty involved. The extension embodies the introduction of specific robust design goals and new robust solution constraints anchored in the mathematical constructs of Error Margin Indices (EMIs) and Design Capability Indices (DCIs) to determine “satisficing” robust design specifications across analytical model-based process chains. Contributions in this paper include the designer’s ability to explore satisficing robust solution regions when multiple conflicting goals and multiple sources of uncertainty are present. Using the goal-oriented inverse design method, robust solutions are propagated in an inverse manner. We demonstrate the efficacy of the method and the associated robust design functionalities using an industry-inspired hot rolling and cooling process chain example problem for the production of a steel rod. In this example, we showcase the formulation of multiple mechanical property goals for the end product using the robustness metrics and the exploration of satisficing robust solutions for material microstructure after the cooling process using the robust solution constraints. The robust solutions thus identified are communicated in an inverse manner using the design method to explore satisficing robust solutions for the microstructure generated after the hot rolling process. Using the example, we demonstrate the robust co-design of material, product, and associated manufacturing processes. The method and the associated design constructs are generic and support the formulation and inverse robust design exploration under uncertainty of similar problems involving a sequential, analytical model-based flow of information across process chains.

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.

Taxonomy for classifying engineering decision problems and support systems

1995 ◽  
Vol 9 (5) ◽  
pp. 427-438 ◽  
Author(s):  
David G. Ullman ◽  
Bruce D'Ambrosio
Keyword(s):  
Decision Support ◽  
Engineering Design ◽  
Quantitative Data ◽  
Decision Problems ◽  
Design Decision ◽  
Decision Support Tools ◽  
Design Decisions ◽  
Wide Range ◽  
Support Tools ◽  
Need Support

AbstractThe design of even the simplest product requires thousands of decisions. Yet few of these decisions are supported with methods on paper or on computers. Is this because engineering design decisions do not need support or is it because techniques have yet to be developed that are usable on a wide basis? In considering this question a wide range of decision problem characteristics need to be addressed. In engineering design some decisions are made by individuals, others by teams – some are about the product and others about the processes that support the product – some are based on complete, consistent, quantitative data and others on sparse, conflicting, qualitative discussions. To address the reasons why so little support is used and the characteristics of potentially useful decision support tools, a taxonomy of decision characteristics is proposed. This taxonomy is used to classify current techniques and to define the requirements for an ideal engineering design decision support system.

scholarly journals Association of Yeast Adenylyl Cyclase with Cyclase-Associated Protein CAP Forms a Second Ras-Binding Site Which Mediates Its Ras-Dependent Activation

2000 ◽  
Vol 20 (1) ◽  
pp. 26-33 ◽  
Author(s):  
Fumi Shima ◽  
Tomoyo Okada ◽  
Masahiro Kido ◽  
Hiroyoshi Sen ◽  
Yasuhiro Tanaka ◽  
...  
Keyword(s):  
Binding Site ◽  
Adenylyl Cyclase ◽  
Posttranslational Modification ◽  
Binding Activity ◽  
The Other ◽  
Strong Interactions ◽  
Ras Signaling ◽  
Critical Determinant ◽  
Strength Of Interaction ◽  
Repeat Domain

ABSTRACT Posttranslational modification, in particular farnesylation, of Ras is crucial for activation of Saccharomyces cerevisiaeadenylyl cyclase (CYR1). Based on the previous observation that association of CYR1 with cyclase-associated protein (CAP) is essential for its activation by posttranslationally modified Ras, we postulated that the associated CAP might contribute to the formation of a Ras-binding site of CYR1, which mediates CYR1 activation, other than the primary Ras-binding site, the leucine-rich repeat domain. Here, we observed a posttranslational modification-dependent association of Ras with a complex between CAP and CYR1 C-terminal region. When CAP mutants defective in Ras signaling but retaining the CYR1-binding activity were isolated by screening of a pool of randomly mutagenized CAP, CYR1 complexed with two of the obtained three mutants failed to be activated efficiently by modified Ras and exhibited a severely impaired ability to bind Ras, providing a genetic evidence for the importance of the physical association with Ras at the second Ras-binding site. On the other hand, CYR1, complexed with the other CAP mutant, failed to be activated by Ras but exhibited a greatly enhanced binding to Ras. Conversely, a Ras mutant E31K, which exhibits a greatly enhanced binding to the CYR1-CAP complex, failed to activate CYR1 efficiently. Thus, the strength of interaction at the second Ras-binding site appears to be a critical determinant of CYR1 regulation by Ras: too-weak and too-strong interactions are both detrimental to CYR1 activation. These results, taken together with those obtained with mammalian Raf, suggest the importance of the second Ras-binding site in effector regulation.

Intelligent Algorithm of Machine Robust Design Orthogonal Optimization Based on Analysis of Variance Ratio

2010 ◽  
Vol 102-104 ◽  
pp. 301-305
Author(s):  
Yong Xian Li ◽  
Bin Wang ◽  
Guang Ping Peng
Keyword(s):  
Analysis Of Variance ◽  
Robust Design ◽  
Orthogonal Array ◽  
Minimum Variance ◽  
Design Parameters ◽  
Variance Ratio ◽  
Intelligent Algorithm ◽  
Local Circulation ◽  
Robust Solution ◽  
Orthogonal Optimization

A new intelligent orthogonal optimization algorithm for robust design is proposed in order to improve accuracy and efficiency. The next searching direction and searching range of variables are determined by variance ratio after the robust optimization model is firstly calculated by design parameters on orthogonal array. New orthogonal array for further optimization is formed intelligently by analysis of variance ratio. The intelligent orthogonal optimization is performed until error value of each variable is equal to zero or is equivalent, which is the optimal robust solution. Correspondingly, the variable range corresponding to the minimum variance ratio in the orthogonal array in preceding step is the tolerance of the optimal robust solution, which means that there is no need for special tolerance design. This paper takes a cam profile as an example to perform robust design. The simulation results prove that the new intelligent algorithm for robust design has many advantages, such as less calculation time, higher speed, no exiting of prematurity of local circulation and slow convergence of global search.

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