bluuebunny/crossref_metadata_2025 huggingface dataset:
Probabilistic Evaluation of Product Development Task Planning Using Worth Flow Analysis
Authors: Miwa Toshiharu , Aoyama Hideki , Ishii Kosuke
Published: July 2009

The acceleration of the product development cycle continues to be a significant challenge for manufacturing firms around the world. The present paper describes a task planning method that takes the uncertain relationships among the product components into consideration in order to reduce the development time in large-scale and complicated product development with uncertainty at the early stage of product development. We developed a probabilistic worth flow analysis to evaluate each product component for task prioritization with an uncertain relationship among product components. The method calculates the probabilistic distribution of worth flow of each product component based on the probabilistic relationship among product components with the Monte Carlo simulation and determines the development sequence of each component so as to minimize the possibility with the highest feedback information across the task groups. The present paper describes an example of a generic hair drier with a simple mechanical structure developed using the proposed method in order to reduce the uncertainty of feedback information across the task groups while maintaining the uncertainty within same task groups in case the uncertainty has an asymmetric distribution.
A Pareto Approach to Aligning Public and Private Objectives in Vehicle Design
Authors: Frischknecht Bart , Papalambros Panos
Published: July 2009

The quest for producing vehicles friendlier to the environment is often impeded by the fact that a producer private good objective, such as maximum profit, competes with the public good objective of minimizing impact on the environment. Contrary to commercial claims, there may be no defined decision maker in the vehicle production and consumption process who takes ownership of the public good objective, except perhaps the government. One way ecofriendly products could become more successful in the marketplace is if public and private good objectives become more aligned to each other. This paper introduces three metrics for comparing Pareto curves in bi-objective problems in terms of relative level of objective competition. The paper also presents a quantitative way of studying an individual firm’s trade-off between profit and fuel consumption for automotive products, currently undergoing an historic evolution in their design. We show how changes in technology, preferences, competition, and regulatory scenarios lead to Pareto frontier changes, possibly eliminating it altogether.
A Learning and Inference Mechanism for Design Optimization Problem (Re)-Formulation Using Singular Value Decomposition
Authors: Sarkar Somwrita , Dong Andy , Gero John S.
Published: July 2009

This paper presents a knowledge-lean learning and inference mechanism based on Singular Value Decomposition (SVD) for design optimization problem (re)-formulation at the problem modeling stage. The distinguishing feature of the mechanism is that it requires very few training cases to extract and generalize knowledge for large classes of problems sharing similar characteristics. The genesis of the mechanism is based on viewing problem (re)-formulation as a statistical pattern extraction problem. SVD is applied as a dimensionality reduction tool to extract semantic patterns from a syntactic formulation of the design problem. We explain and evaluate the mechanism on a model-based decomposition problem, a hydraulic cylinder design problem, and a medium-large scale Aircraft Concept Sizing problem. The results show that the method generalizes quickly and can be used to impute relations between variables, parameters, objective functions, and constraints when training data is provided in symbolic analytical form, and is likely to be extensible to forms when the representation is not in analytical functional form.
Modular Wireless Wheeled In Vivo Surgical Robots
Authors: Platt Stephen R. , Hawks Jeff A. , Rentschler Mark E. , Redden Lee , Farritor Shane , Oleynikov Dmitry
Published: July 2009

Minimally invasive abdominal surgery (laparoscopy) results in superior patient outcomes as measured by less painful recovery and an earlier return to functional health compared to conventional open surgery. However, the difficulty of manipulating traditional laparoscopic tools from outside the patient’s body generally limits these benefits to patients undergoing procedures with relatively low complexity. The use of miniature in vivo robots that fit entirely inside the peritoneal cavity represents a novel approach to laparoscopic surgery. Our previous work has demonstrated that mobile and fixedbased in vivo robots can successfully operate within the abdominal cavity and provide surgical vision and task assistance. All of these robots used tethers for power and data transmission. This paper describes recent work focused on developing a modular wireless mobile platform that can be used for in vivo sensing and manipulation applications. The robot base can accommodate a variety of payloads. Details of the designs and results of ex vivo and in vivo tests of robots with biopsy grasper and physiological sensor payloads are presented. These types of self-contained surgical devices are much more transportable and much lower in cost than current robotic surgical assistants. These attributes could ultimately allow such devices to be carried and deployed by non-medical personnel at the site of an injury. A remotely located surgeon could then use these robots to provide critical first response medical intervention irrespective of the location of the patient.
Performing Ergonomic Analysis in Virtual Environments: A Structured Protocol to Assess Humans Interaction
Authors: Mengoni Maura , Peruzzini Margherita , Mandorli Ferruccio , Bordegoni Monica , Caruso Giandomenico
Published: July 2009

Virtual Reality (VR) systems provide new modes of human computer interaction that can support several industrial design applications improving time savings, reducing prototyping costs, and supporting the identification of design errors before production. Enhancing the interaction between humans and virtual prototypes by involving multiple sensorial modalities, VR can be adopted to perform ergonomic analysis. The main problems deal with the evaluation both of functional and cognitive sample users behavior as VR interfaces influence the perception of the ergonomic human factors. We state that ergonomic analysis performed in virtual environment can be successful only if supported with a structured protocol for the study both of functional and cognitive aspects and with the proper VR technologies combination that answers to the specific analysis tasks. An ergonomic analysis protocol is presented. It allows the assessment of the consumers’ response in term of behavioral and cognitive human factors, comprehending both operational and emotional agents. The protocol is also used to identify the best combination of visualization and haptic interfaces to perform the analysis. An experimental example, belonging to house appliances field is adopted to investigate the application of the protocol in the virtual set up.
Uncertainty Analysis of Damage Evolution Computed Through Microstructure-Property Relations
Authors: Acar Erdem , Solanki Kiran , Rais-Rohani Masoud , Horstemeyer Mark F.
Published: July 2009

Uncertainties in material microstructure features can lead to variability in damage predictions based on multiscale microstructure-property models. In this paper, we present an analytical approach for uncertainty analysis by combining a dimension reduction technique for evaluation of statistical moments of a random response, such as damage, with probability distribution fitting based on the extended generalized lambda distribution. This approach is used to analyze the effects of uncertainties pertaining to structure-property relations of an internal state variable plasticity-damage model that predicts failure. Using an un-notched A356 cast aluminum alloy tension specimen as an example, the predictions for damage uncertainty based on the proposed approach are compared with those found using the first order Taylor series approximation and direct Monte Carlo simulation. In particular, the spatial variabilities in microstructural properties, the constitutive model parameter sensitivities, and the effect of boundary condition uncertainties on the damage evolution and final failure are examined. The results indicate that the higher the strain the greater the scatter in damage, even when the uncertainties in the material plasticity and microstructure parameters are kept constant. For A356, the mathematical sensitivity analysis results related to damage uncertainty are consistent with the physical nature of damage progression. At the very beginning, the initial porosity and void nucleation are shown to drive the damage evolution. Then, void coalescence becomes the dominant mechanism. And finally when approaching closer to failure, fracture toughness is found to dominate the damage evolution process.
Dynamic Model of Process Planning for Top-Down Collaborative Assembly Design
Authors: Yang Youdong , Zhang Shuting , Li Zhihua
Published: July 2009

The design process of top-down collaborative assembly design is high parallel. There are complex task relationships not only in a task group but also among different task groups, which we call them as inside and outside relationships. A dynamic model of process planning based on hierarchical object-oriented Petri-net (HOOPN) is constructed for top-down collaborative assembly design. The dynamic model represents the outside and inside task relationships including parallel, sequential and coupling relationships. Based on the dynamic model, the dynamic supervising, analysis and decision-making for the states of the design process are implemented. The fuzzy overall evaluation model (FOEM) is utilized for risk evaluation of the design process. The task execution is influenced by local and global risk level from FOEM. Finally, the whole process planning is adjusted and controlled dynamically by the special risk decision-making mechanism.
A Contribution to the Simulation of Molded Micro Components and Systems With Regard to the Grain Structure
Authors: Albers Albert , Enkler Hans-Georg , Leslabay Pablo
Published: July 2009

Experimental work for characterizing materials’ properties as well as components’ and systems’ behaviors have to be supplemented by numerical analyses when regarding micro components and systems. In order to accomplish a complete possibilities’ overview for micro machines these analyses should cover both component and system issues. On a component level, established macroscopic approaches are extended by methods that allow the consideration of components’ grain structures influence, including possible superficial and internal defects. Because of technological restrictions, especially when applying miniaturized conventional manufacturing techniques, shape and material deviations cannot be scaled down in the same dimensions like micro parts. Thus, high tolerances accepted for the individual components and their effects on the expected transfer behavior of the whole system are taken primarily into account. This paper presents approaches for the simulation of micro components and systems using the Finite Element Method and Multi Body Simulation. Methods to overcome the above mentioned issues will be shown, as well as the effects of grain structure on the stress distribution in the individual components. Some effects over the system’s behavior of this inhomogeneous stress distribution are also discussed.
Multi-Category Design of Bundled Products for Retail Channels Considering Demand Uncertainty and Competition
Authors: Williams N. , Azarm S. , Kannan P. K.
Published: July 2009

Modern retailers now control in excess of 70% of many markets and thereby control the access manufacturers have to the end customer. Success of a new product design therefore depends upon acceptance of the product by the powerful retailer as well as the end customer. One prevalent approach to increasing both retailer and manufacturer revenues is to improve the attractiveness of a product offering by bundling related items together for one price. To be most effective, bundled products should be developed with an integrated design approach that seeks to achieve utility for the end customer as well as cost efficiencies through measures such as using common parts. We propose a bundled product design approach that endogenizes the profit maximizing prices set by the channel controlling (monopolist) retailer. The approach accounts for demand dependencies between the product categories and thus the impact of the bundle and cross-category competition on proposed engineering designs is known. Additionally, the approach simultaneously considers uncertainty in engineering design, competing manufacturer product attributes and customer preferences to ensure acceptable product profitability and market share under interval uncertainty. A bundled product design case study is presented for two complimentary power tools. Manufacturer profit and market share are optimized both deterministically and under uncertainty. We find that considering demand dependencies can create optimal bundle and individual product designs that increase profits for both retailer and manufacturer.
Collaborative Naming for Replicated Collaborative Solid Modeling System
Authors: Jing Shuxu , He Fazhi , Cai Xiantao , Liu Huajun
Published: July 2009

In this paper, a framework of full replicated collaborative solid modeling and a method for multi-user interaction to support natural, free, fast and less-constrained multi-user human-to-human interaction is proposed. Particularly, the challenges and problems of topological entity correspondence by name across collaborative modeling sites in replicated CSM system is analyzed. And a method to achieve name correspondence during collaborative modeling sessions in replicated CSM system is proposed. The proposed method is tested in a prototype system of replicated CSM, which employs ACIS as the geometric modeling kernel and adopts winsocket API for communication purpose, developed by our research group.
Dynamic Characteristics of Planar Compliant Parallel-Guiding Mechanisms
Authors: Wang Wenjing , Yu Yueqing
Published: July 2009

Dynamic effects are very important to improving the design of compliant mechanisms. An investigation on the dynamic characteristics of planar compliant parallel-guiding mechanism is presented. Based on the pseudo-rigid-body model, the dynamic model of planar compliant parallel-guiding mechanisms is developed using the numerical methods at first. The natural frequency is then calculated, and frequency characteristics of this mechanism are studied. The numerical results show the accuracy of the proposed method for dynamic modeling of compliant mechanisms, and the relationships between the natural frequency and design parameters are analyzed clearly.
The Application of Product Platform Design to the Reuse of Electronic Components Subject to Long-Term Supply Chain Disruptions
Authors: Sandborn Peter , Prabhakar Varun , Eriksson Bo
Published: July 2009

Component reuse in multiple products has become a popular way to take advantage of the economies of scale across a family of products. Amongst electronic system developers there is a desire to use common electronic parts (chips, passive components, and other parts) in multiple products for all the economy of scale reasons generally attributed to platform design. However, the parts in electronic systems (especially those manufactured and supported over significant periods of time), are subject to an array of long-term lifecycle supply chain disruptions that can offset savings due to part commonality depending on the availability of finite resources to resolve problems on multiple products concurrently. In this paper we address the application of product platform design concepts to determine the best reuse of electronic components in products that are subject to long-term supply chain disruptions such as reliability and obsolescence issues. A detailed total cost of ownership model for electronic parts is coupled with a finite resource model to demonstrate that, from a lifecycle cost viewpoint, there is an optimum quantity of products that can use the same part beyond which costs increase. The analysis indicates that the optimum part usage is not volume dependent, but is dependent on the timing of the supply chain disruptions. This work indicates that the risk and timing of supply chain disruptions should be considered in product platform design.
Relating Two Domains via a Third: An Approach to Overcome Ambiguous Attributions Using Multiple Domain Matrices
Authors: Kreimeyer Matthias , Braun Stefanie , Gu¨rtler Matthias , Lindemann Udo
Published: July 2009

Design Structure Matrices (DSM) and Domain Mapping Matrices (DMM) are commonly used to model and analyze the relationships within one domain (DSM) or between two domains (DMM). Being assembled into one larger square matrix, having DSMs on its diagonal and DMMs in all other fields, a so-called Multiple Domain Matrix (MDM) is formed. When relating two domains using a DMM, a problem arises when the nature of one individual relationship between the two domains is to be described. Usually, this is modeled by annotating each relationship with the additional information, much like comments in spreadsheet software. This, however, is yet impossible if the relationships should be in matrix notation to allow for algorithmic matrix analyses. Equally, this way, the annotations are not accessible as elements of another matrix, e.g. as DSM. This paper suggests a generic principle to solve the described problem in a way consistent with the matrix methodology. It proposes an approach using MDM and is thereby able to unambiguously provide the nature of each relationship between the elements of two domains. As a DSM is a mere case of a DMM having two identical domains, the approach proposed can equally be used to enrich the relationships within a DSM.
Adaptronic Revolute Joints for Parallel Robots Based on Simultaneous Quasi-Statical Axial and Radial Clearance Adjustment
Authors: Pavlovic Nenad , Keimer Ralf , Franke Hans-Joachim
Published: July 2009

Robots based on parallel kinematics feature low moved masses, allowing for better dynamic performance compared to serial mechanisms. Otherwise, the known drawbacks, like occurrence of singularities or bad radio of work space to installation area, hinder their fully industrial establishment. In order to overcome some of these drawbacks, development of specific and optimized robot components, like rods or joints, becomes necessary. Development of joints for parallel robots is determined by numerous contradictory requirements which cause different goal conflicts. In this work, possibilities for dissolving of such goal conflicts by means of adaptronic joints (joints with integrated piezo-actuators) are discussed. To deal with these complex issues this paper focuses on three major areas: firstly, conventional joint concepts, including their main flaws; secondly, new, adaptronic joint concepts based on quasi-statical clearance adjustment with two laboratory prototypes and their improvements over the old solutions; thirdly and finally, some of possible consequences of the new joint concepts for the overall performance of parallel robots. By drawing on experimental results derived from laboratory tests, it is possible to show how implementation of the developed joint prototypes could influence friction characteristic of the whole robot system.
Performance Optimization of Semiconductor Manufacturing Equipment by the Application of Discrete Event Simulation
Authors: Pfeffer Markus , Oechsner Richard , Pfitzner Lothar , Ryssel Heiner , Ocker Berthold , Verdonck Patrick
Published: July 2009

Semiconductor wafer fabrication facilities (wafer fabs) are amongst the most complex production facilities. State-of-the-art wafer fabs comprise a large product variety, hundreds of processing steps per product, almost hundreds of machines of different types, and automated transportation systems combined with reentrant flows throughout the fab. In addition to the high complexity, wafer fabs require very high capital investment and an undisturbed operation. Semiconductor manufacturers are facing fierce competition as more global capacity is being added. Through this intense competition, semiconductor manufacturers have to improve their processes from a technological as well as from a logistical point of view in order to be successful within the global market. The logistics not only involves fab wide optimization strategies but also the individual equipment performance, for example cycle time and throughput, has to be considered. In this paper, the need for performance optimization of semiconductor manufacturing equipment is identified and the capability of discrete event simulation for such optimizations is being elaborated. Characteristics of different types of simulation models are described and the simulation model selection is explained. For case studies, several simulation models of different semiconductor manufacturing equipment have been developed. Using five examples, different optimization strategies, dependent on the application of the semiconductor manufacturing equipment, have been investigated by discrete event simulation. The paper shows the influence of the integration of metrology into deposition equipment, the impact of different batch sizes for oxidation processes, and the optimized dimensioning of photolithography equipment. Furthermore, the throughput and cycle time of different deposition equipment are optimized by the evaluation of various improvement strategies. All investigations have been performed with real data extracted from already utilized equipment or at least with data from the equipment suppliers of prototype equipment.
A Numerical Modelling of Two-Phase Flow System
Authors: Chung Moon-Sun , Kim Jong-Won
Published: July 2009

A two-dimensional two-fluid model for two-phase flow system is proposed. This two-dimensional model is based on the hyperbolic one-dimensional model which is improved in its mathematical property by adopting the interfacial pressure jump terms in the momentum equations. Owing to this surface-tension effect incorporated in the momentum equations, eigenvalues of the equation system can be obtained analytically and they are proved to be all real. The eigenvectors can also be obtained analytically with linearly independent form. Further, they consist of phasic convective velocities, the sound speed of gas phase, and the sound speed of liquid phase. Consequently, the governing equation system is mathematically hyperbolic with reasonable characteristic speeds by which the upwind numerical method avails. Advantages and possibility of the present model are discussed in some detail.
Mapping Shape Geometry and Emotions Using Fuzzy Logic
Authors: Achiche Sofiane , Ahmed Saeema
Published: July 2009

An important aspect of artifact/product design is defining the aesthetic and emotional value. The success of a product is not only dependent on it’s functionality but also on the emotional value that it creates to its user. However, if several designers are faced with a task to create an object that would evoke a certain emotion (aggressive, soft, heavy, friendly, etc.) each would most likely interpret the emotion with a different set of geometric features and shapes. In this paper the authors propose an approach to formalize the relationship between geometric information of a 3D object and the intended emotion using fuzzy logic. To achieve this; 3D objects (shapes) created by design engineering students to match a set of words/emotions were analyzed. The authors identified geometric information as inputs of the fuzzy model and developed a set of fuzzy if/then rules to map the relationships between the fuzzy sets on each input premise and the output premise. In our case the output premise of the fuzzy logic model is the level of belonging to the design context (emotion). An evaluation of how users perceived the shapes was conducted to validate the fuzzy logic model and showed a high correlation between the fuzzy logic model and user perception.
A Simple ABS Control Strategy
Authors: Taheri Saied
Published: July 2009

A new control strategy for Anti-lock Braking System was developed to improve vehicle braking during emergency maneuvers. Various prediction and re-selection methods were evaluated using a nonlinear vehicle model. To improve upon the evaluated control strategies, Conjugate Boundary method and Poincare Mapping concept were used. The new control strategy developed has proved to be more effective during emergency braking and steering maneuvers.
A New Control Algorithm for Vehicle Stability Control
Authors: Tamaddoni Seyed Hossein , Taheri Saied
Published: July 2009

A new control algorithm and the adaptation laws required for estimation of unknown vehicle parameters have been developed for vehicle stability control (VSC). This algorithm is based on the Lyapunov Direct Method. A vehicle model with two degrees of freedom (DOF) was used to develop the control algorithm. In developing the equations of motion for this simple model, a new approach for introducing the needed stabilizing forces and moments was developed. In addition, an eight DOF model was developed for control algorithm evaluation. The model includes lateral, longitudinal, yaw, and roll motions of the body plus the rotational DOFs for all of the four wheels. Also included in the model is a transient tire model taking into account the tire lateral relaxation length. Using the validated 8 DOF simulation model, the new control algorithm was evaluated and the results show the advantages of using such an approach for enhancing vehicle stability during emergency steering maneuvers.
Mobility Analysis of Some “Paradoxical Mechanisms” Using a General Methodology
Authors: Liu Jingfang , Huang Zhen
Published: July 2009

The “Modified Gru¨bler-Kutzbach Criterion” achieved success in calculating the mobility of some mechanisms. Recently, with continuous applications of the criterion, a systematic methodology not only a formula has finally formed. This paper briefly presents the systematical methodology and deals with the analysis of full-cycle mobility for four representative “paradoxical mechanisms”. The purpose of this paper is to show that the methodology is more feasible and general.
Singular Assembly Configurations and Configuration Bifurcation Characteristics of the SRHGSMP
Authors: Wang Yu-Xin , Li Yu-Tong , Huang Zheng , Pian Shuang-Xia
Published: July 2009

In this paper, the configuration bifurcation characteristics at the vicinities of singular points going with different input parameters are investigated. Then, with the aid of the assembly configurations at the theoretical singular points, the reasons to cause the singularities are analyzed. We find that the dimensional-utmost singularities, line vectors correlation singularities and Jacobian matrix correlation singularities can occur individually or jointly while choosing different number of input parameters. The number and the combination form of the input parameters have great influences on the complexity of the singularities and the curvature radiuses of the configuration curves. Selecting a group of adjacent input parameters, the simple configuration bifurcation and the large singularity-free input parameters zones can be obtained. And adopting multi-input parameters, the self-motion regions and the singularity avoidance errors can be reduced. These new discoveries are valuable and of significance for the trajectory design, the singularity avoidance, and the self-motion control for the parallel manipulator, as well as the parallel tools.
Increasing Innovation: Presentation and Evaluation of the Wordtree Design-by-Analogy Method
Authors: Linsey J. S. , Wood K. L. , Markman A. B.
Published: July 2009

Numerous examples of innovation through analogy are found throughout current trade journals, magazines and product offerings. Design-by-analogy is a powerful tool in creative design, but generally relies on unproven, ad-hoc approaches. Although a few notable computational knowledge bases have been created to support analogous design, very few methods provide suitable guidance on how to identify analogies and analogous domains. This paper presents a novel approach, referred to as the WordTree Design-by-Analogy Method, for identifying analogies as part of the ideation process. The WordTree Method derives its effectiveness through a design team’s knowledge and readily available information sources but does not require specialized computational knowledge bases. A controlled experiment and an evaluation of the method with redesign projects illustrate the method’s influence in assisting engineers in design-by-analogy. Unexpected and unique solutions are identified using the method. The experimental results also highlight potential improvements for the method and areas for future research in engineering design theory.
Teaching Creative Engineering: Education in Japan and the USA
Authors: Ito Teruaki , Slocum Alexander H.
Published: July 2009

This paper describes two approaches to teaching engaging creative engineering design classes. Both of these classes have evolved over many years using feedback from annual class reviews. One is the computer-aided design class, CAD-EX, at the University of Tokushima (UT) in Japan, and the other is the introductory design and manufacturing class, 2.007, at the Massachusetts Institute of Technology (MIT) in the USA. Comparing these two classes conducted in two difference countries, this paper discusses how we created learning environments that engage students in a variety of design-related activities.
Design of Solar Parabolic Trough Collector by FEM
Authors: Tao Lei , Ling Xiang , Zhu Yuezhao
Published: July 2009

Structural optimum design of the collector was presented in this paper by using finite element software ABAQUS incorporated with genetic optimal algorithms. In the optimization of trusses, cross-sectional areas of members were considered as variables and the maximum node displacement was used as the constraint in genetic algorithms. The bending and torsion failure models concerning on the optical accuracy were established for the trough collector. The conversion from the wind load into the dead load was acted on the collector. The stress and displacement for the collector were obtained under 6th level gale, 8th level gale and 10th level gale, respectively with a range of pitching angles of 30°, 45° and 90°. The maximum stress and node displacement were obtained under 10th level gale with a pitch angle of 90°. The maximum node displacement occurred near the brim of the parabolic mirror facets. The largest displacement in absorber occurred in the middle. Detailed FEM investigations on the structural behavior were performed to obtain the best possible relationship between optical accuracy and collector cost under various load cases, such as dead load, wind loads for a range of pitching angles of the collector and wind directions, for alternate designs, complex computer modeling and ray tracing.
Multi-Aspect Component Models: A Framework for Model Reuse in SysML
Authors: Jobe Jonathan M. , Johnson Thomas A. , Paredis Christiaan J. J.
Published: July 2009

In this paper, a framework is defined for cost-effective reuse of engineering analysis models in the context of systems engineering. As systems engineering problems become increasingly complex and involve an increasing number of stakeholders, it is important that the knowledge required to solve these problems is formulated and communicated in a formal fashion. To allow such formal communication to occur in a cost-effective manner, a framework is introduced based on model reuse and composition. In this framework, engineering analysis models are associated with components and characterized by aspects. The resulting containers of related models are called Multi-Aspect Component Models (MAsCoMs). To allow the MAsCoMs to be incorporated seamlessly into systems engineering practice, the models are defined in the Systems Modeling Language (OMG SysML™). After introducing the basic modeling constructs, their implementation and composition is illustrated in the context of the design of a hydraulically actuated log splitter.
Holistic Engineering Design: A Combined Synchronous and Asynchronous Approach
Authors: Conway A. P. , Giess M. D. , Lynn A. , Ding L. , Goh Y. M. , McMahon C. A. , Ion W. J.
Published: July 2009

To aid the creation and through-life support of large, complex engineering products, organizations are placing a greater emphasis on constructing complete and accurate records of design activities. Current documentary approaches are not sufficient to capture activities and decisions in their entirety and can lead to organizations revisiting and in some cases reworking design decisions in order to understand previous design episodes. Design activities are undertaken in a variety of modes; many of which are dichotomous, and thus each require separate documentary mechanisms to capture information in an efficient manner. It is possible to identify the modes of learning and transaction to describe whether an activity is aimed at increasing a level of understanding or whether it involves manipulating information to achieve a tangible task. The dichotomy of interest in this paper is that of synchronous and asynchronous working, where engineers may work alternately as part of a group or as individuals and where different forms of record are necessary to adequately capture the processes and rationale employed in each mode. This paper introduces complimentary approaches to achieving richer representations of design activities performed synchronously and asynchronously, and through the undertaking of a design based case study, highlights the benefit of each approach. The resulting records serve to provide a more complete depiction of activities undertaken, and provide positive direction for future co-development of the approaches.
An Approach to Quantifying Design Flexibility for Mass Customization in Early Design Stages
Authors: Cormier Phil , Olewnik Andrew , Lewis Kemper
Published: July 2009

With the increasing stratification of customer preferences, companies must offer a number of options to remain competitive. Current methodologies, such as product families, seek to offer more options to the consumer while minimizing costs to the company. Customizable products are striving to offer the customer what they truly desire by increasing the level of influence the consumer has on their instance of the design. As the shift from cosmetic changes and modular options continues, systems will be required to have a greater amount of design flexibility to allow for the changes made by individual consumers. Drawing on reconfigurable system and product family research, metrics for flexibility are proposed for use in the early stages of the design process. Discussion focuses on functional aspects of a product which affect flexibility and the rational behind the component metrics representing their flexibility. The goal of the metrics is to assist with the evaluation of design options by rating the overall flexibility of the system early in the design process. A case study is presented to demonstrate the use of the metrics.
Effect of Model Element Fidelity Within a Complex Function-Based Behavioral Model
Authors: Hutcheson Ryan S. , McAdams Daniel A. , Stone Robert B. , Tumer Irem Y.
Published: July 2009

The Function-based Behavioral Modeling (FBBM) design tool was introduced in prior work as a means of using formal functional modeling as the foundation for creating detailed mathematical models of system behavior. The overall objective of this work is to create a framework for partitioning modeling efforts into functional elements and promoting model storage and re-use through the use of functional models. In prior work, the FBBM method was introduced to model the complete vehicle dynamics of a Formula SAE racecar, highlighting the representation of functionality and the development of behavioral models. The objective of the work presented in the current paper is to demonstrate the ability to incorporate models of varying fidelity within a function-based behavioral model of a complex system. Additionally, the impact of model fidelity on the model’s predictions is addressed. A previously developed model is used as a foundation for developing the necessary new models and illustrating the impact of model fidelity on performance predictions when selecting a tire during early design. The results illustrate that the FBBM framework allows models of varying fidelity to be quickly made and their effect on predicted performance to be measured in order to assist critical early design choices.
Early Stage Failure Modeling and Analysis Applied to a Wave Energy Converter
Authors: Brown Adam , Tumer Irem Y. , Paasch Robert
Published: July 2009

Ocean wave power is still in its infancy. New systems are conceptualized on nearly a daily basis. The systems vary wildly in complexity and scope, but share one common trait; they have never been built. This scenario is ripe with massive financial risk and of course the possibility of reward. Providing an early stage failure and safety analysis could greatly improve the design process by identifying potential weak points in the system prior to the costly build and testing stages of product development. More broadly, determining potentially successful conceptual designs which should be pursued becomes critical. However, there is currently no tool readily available for such a task. In this paper, we adapt and simplify function-based modeling and analysis to fill this void. Completing a function based failure analysis allows engineers to evaluate the dependencies and fault tolerance of their system early in the design stage. This process aids in catching design problems when they are still relatively cheap to address. This paper proposes the System Functionality Method for conceptual design stage analysis. This proposed method places systems and subsystems in a flow (mass, energy, and signal) based on their location, and assigns functionality numbers to help describe their contribution to the system. Component or sub-system faults are then used to determine the effect on other components and the system as a whole. The process is unique in its simplicity and adaptability to the conceptual stage of designing wave energy technologies.
Translating Terms of the Functional Basis Into Biologically Meaningful Keywords
Authors: Cheong Hyunmin , Shu L. H. , Stone Robert B. , McAdams Daniel A.
Published: July 2009

Biology has long been recognized as an excellent source of analogies and stimuli for engineering design. Previous work focused on the systematic identification of relevant biological analogies by searching for instances of functional keywords in biological information in natural language format. This past work revealed that engineering keywords couldn’t always be used to identify the most relevant biological analogies, as the vocabularies between biology and engineering are sufficiently distinct. Therefore, a method of identifying biologically meaningful keywords that correspond to engineering keywords was developed. Here, we apply and refine this method by generating biologically meaningful keywords for the terms of the Functional Basis, which is widely accepted as a standardized representation of the functionality of engineering products. We present insights gained on the selection of biologically meaningful keywords for the function sets based on semantic relations. We then observe the use of our keywords by providing 4th year undergraduate design students with the biologically meaningful keywords that are related to the desired functions of their design projects.
Effects of Dichotomous Lexical Stimuli in Concept Generation
Authors: Chiu I. , Shu L. H.
Published: July 2009

The relationship between language and reasoning motivates us to study the use of language within engineering design. This paper describes our continued investigation of language as stimuli for concept generation. Specifically we investigate dichotomous lexical stimuli that are related to the problem in either a disagreeing, incongruent manner or in an agreeing, congruent manner. This is a follow-up investigation where we extend previous experiments to include both congruent and incongruent stimuli to enable comparison of differences between designer behavior and concepts. A between-subjects think-aloud experiment was performed where participants were presented with a problem and asked to generate concepts to address the problem. Half the participants were provided with incongruent stimuli and the remaining were provided with congruent stimuli. Participants provided with incongruent stimuli used the stimulus words as verbs more often than the participants provided with congruent stimuli. Verbs possess several properties desirable for use as design stimuli including the increased introduction of new lexicalized concepts to the concept generation process. When two independent raters scored the concepts, there was a positive correlation between the raters that concepts developed with incongruent stimuli were more novel. Understanding the effects of different lexical stimulus types on concept generation contributes to the development of design support tools that exploit the relationship between language and reasoning to increase design novelty.
Design Team Framing: Paths and Principles
Authors: Hey Jonathan , Yu Jonathan , Agogino Alice M.
Published: July 2009

This paper addresses two major challenges new product development teams face in making a product people want. The first challenge is to frame the design situation based on a real need of a customer. The second challenge is to get everyone on the team in agreement about what that framing is — everyone needs to be on the same page about what it is they’re doing. Yet these two challenges are not independent, they are intertwined with each other, connected by the concrete research and sharing activities the teams perform. We introduce a framework to help understand the path of a design team along these two dimensions as well as illustrations of the three most common paths observed among graduate multidisciplinary new product development teams as supported by interviews and survey data. These case studies form the basis of four themes to help teams navigate the new product development process.
On Pattern Recognition in Rule-Based Topology Modification
Authors: Kormeier Thomas , Rudolph Stephan
Published: July 2009

Classical topology optimization aims at achieving a problem suited material distribution in a structure by identification of lightly loaded areas and local element-wise reduction of stiffness. The resulting topologic layout often contains small substructures which are complicated to manufacture, hence requiring an additional manual smoothing during the structural interpretation phase. One major drawback of this approach is that the results still have to be interpreted by an engineer and consequently be translated into a feasible structure. In order to gain a first conceptual yet topologically sound design proposal for composite structures, this paper presents an alternate method for an explicit, pattern based topology modification approach combined with numerical simulation of tape-laying technology. It is assumed that certain patterns exist in stress fields that are extractable by pattern recognition algorithms known from image processing. In the case that prototypical structural reinforcements for such stress patterns can be defined, an automatic topology modification algorithm with the goal of increasing the stiffness is feasible. The classification of these stress patterns is achieved by using dimensionless features matching the stress patterns with their appropriate reinforcements. When integrated into a rule-based conceptual design environment, this explicit topology modification offers the potential to generate simple and easily manufacturable topological reinforcement proposals in an automated structural design loop.
An Integrated Control and Simulation Environment for Mobile Robot Software Development
Authors: Balakirsky Stephen , Proctor Frederick M. , Scrapper Christopher J. , Kramer Thomas R.
Published: July 2009

In order to expedite the research and development of robotic systems and foster development of novel robot configuration, it is essential to develop tools and standards that allow researchers to rapidly develop, communicate, and compare experimental results. This paper describes the Mobility Open Architecture Simulation and Tools Framework (MOAST). The MOAST framework is designed to aid in the development, testing, and analysis of robotic software by providing developers with a wide range of open source robotic algorithms and interfaces. The framework provides a physics-based virtual development environment for initial testing and allows for the seamless transition of algorithms to real hardware. This paper details the design approach, software architecture and specific module-to-module interfaces.
Jacobian-Based Algorithm for Motion Planning for Underactuated Systems Undergoing Forward and Reverse Rotations
Authors: Koh Sung , Chung Wankyun
Published: July 2009

A Jacobian-based algorithm for motion planning for an underactuated system that is a rigid-body operated by two input-rotations is discussed in this paper. The rigid body undergoes a four-rotation fully-reversed (FR) sequence of rotations which consists of a series of initial two rotations about the axes of a coordinate frame attached to the rigid body and subsequent two rotations that undo the proceeding rotations. Due to the insufficient degrees of freedom of four-rotation FR sequences required to achieve all possible orientations, the rigid body cannot achieve some orientations. In order to best approximate these infeasible orientations, the Jacobian-based algorithm is implemented in the sense of least squares. As some orientations can never be attained by a single four-rotation FR sequence, two different four-rotation FR sequences are exploited alternately to ensure the convergence of the proposed algorithm. Assuming the orientation is supposed to be manipulated using three input-rotations, the switching-Jacobian algorithm proposed in this paper has significant practical importance for motion planning for aerospace and underwater vehicles maneuvered using only two input-rotations due to the failure of one of torque-generation mechanisms.
Reliability-Based Shape Optimization of a Pressure Tank Under Random and Stochastic Environments
Authors: Liu Chih-Hao , Chan Kuei-Yuan
Published: July 2009

Reliability-based design of a pressure tank under time-independent random and time-dependent stochastic uncertainties is considered. This pressure tank is an essential element in a reverse osmosis (RO) filtration system for storing filtered water and providing a useable flow rate from the faucet outlet. In this study, we consider the randomness in the welding strength between the upper and lower tanks, and the stochastic pressure applied to the inner surfaces of the tank as the main sources of uncertainty. A pressure tank with 90% reliability against fracture failure is desired. To enable the re-design of the pressure tank, the geometry is parametrized and then used as design variables in a shape optimization scheme. Kriging models are created to approximate the expensive finite element analyses in accessing the performances of each design. The uncertainty model of the welding strength between the upper and lower tanks is found to be well represented by a Gaussian distribution. The stochastic behavior of the pressure loading is modeled by a Markov-chain process. All models are integrated in a reliability-based design optimization problem formulation that has both time-independent and time-dependent reliability constraints. The first passage time and crossover rate are considered in the time-dependent reliability constraint and results of different constraint formulations are compared. The final optimal design satisfies all reliability constraints and reduces the material usage by as many as 46% comparing to the original design.