bluuebunny/crossref_metadata_2025 huggingface dataset:
Design Optimization of Reverse Osmosis Water Desalination Systems via Genetic Algorithms
Authors: Hamza Karim , Shalaby Mohammed , Nassef Ashraf O. , Aly Mohamed F. , Saitou Kazuhiro
Published: March 2011

This paper explores the application of genetic algorithms (GA) for optimal design of reverse osmosis (RO) water desalination systems. While RO desalination is among the most cost and energy efficient methods for water desalination, optimal design of such systems is rarely an easy task. In these systems, salty water is made to flow at high pressure through vessels that contain semi-permeable membrane modules. The membranes can allow water to flow through, but prohibit the passage of salt ions. When the pressure is sufficiently high, water molecules will flow through the membranes leaving the salt ions behind and are collected in a fresh water stream. Typical system design variables for RO systems include the number and layout of the vessels and membrane modules, as well as the operating pressure and flow rate. This paper explores models for single and two-stage RO pressure vessel configurations. The number and layout of the vessels and membrane modules are regarded as discrete variables, while the operating pressures and flow rate are regarded as continuous variables. GA is applied to optimize the models for minimum overall cost of unit produced fresh water. Case studies are considered for four different water salinity concentration levels. In each of the studies, three different types of crossover are explored in the GA. While all the studied crossover types yielded satisfactory results, the crossover types that attempt to exploit design variable continuity performed slightly better, even for the discrete variables of this problem.
Dexterous Workspace of N-PRRR Planar Parallel Manipulators
Authors: Gallant Andre´ , Boudreau Roger , Gallant Marise
Published: March 2011

In this work, a method is presented to geometrically determine the dexterous workspace boundary of kinematically redundant n-PRRR planar parallel manipulators. The dexterous workspace of each non-redundant RRR kinematic chain is first determined using a four-bar mechanism analogy. The effect of the prismatic actuator is then considered to yield the workspace of each PRRR kinematic chain. The intersection of the dexterous workspaces of all the kinematic chains is then obtained to determine the dexterous workspace of the planar n-PRRR manipulator. The Gauss Divergence Theorem applied to planar surfaces is implemented to compute the total dexterous workspace area. Finally, two examples are shown to demonstrate applications of the method.
A Port-Based Agent Approach to Guiding Concept Generation for Customizing Modular Varieties
Authors: Cao Dongxing , Ramani Karthik , Fu Ming Wang , Zhang Runli
Published: March 2011

As the description of design requirements at the earlier design stage is inaccurate and vague, it is difficult to figure out functional structure of a product and make sense product configuration. Therefore, it plays an important role to formally represent the process of design for product development in the conceptual design stage. Furthermore, port, as the location of intended interaction, is crucial to capture component concept and realize conceptual design for multi-solution generation. Agent is considered as an effective approach to collaboratively implementing design problem solving and reasoning. Combining both port and agent may be employed to generate new concepts of the product in order to customize product scheme varieties. In this paper, the product module attributes are firstly described. The objective is to implement modeling of design process for obtaining system new concepts to guide multi-solution generation. Secondly, an effective approach to decomposing design process is presented to describe the process of structure generations and product decomposition by formal representation. According to properties of modularity for product development and component connections, we can calculate the number of component connections and density of components. In addition, product module division and coupling degree analysis are conducted, and coupling degrees are calculated by considering the correspondence ratio and the cluster independence. A port-based knowledge building process is described for functional modeling. A port-agent collaborative design framework is given and describes different agent functions to help designers to obtain new design schemes. Finally, a case study is presented to describe the modeling process of conceptual design.
Studies on the Design of Reverse Osmosis Water Desalination Systems for Cost and Energy Efficiency
Authors: Hamza Karim , Shalaby Mohammed , Nassef Ashraf O. , Aly Mohamed F. , Saitou Kazuhiro
Published: March 2011

This paper explores optimal design of reverse osmosis (RO) systems for water desalination. In these systems, salty water flows at high pressure through vessels containing semi-permeable membrane modules. The membranes can allow water to flow through, but prohibit the passage of salt ions. When the pressure is sufficiently high, water molecules will flow through the membranes leaving the salt ions behind, and are collected in a fresh water stream. Typical system design variables include the number and layout of the vessels and membrane modules, as well as the operating pressure and flow rate. This paper presents models for single and two-stage pressure vessel configurations. The models are used to explore the various design scenarios in order to minimize the cost and energy required per unit volume of produced fresh water. Multi-objective genetic algorithm (GA) is used to generate the Pareto-optimal design scenarios for the systems. Case studies are considered for four different water salinity concentration levels. Results of the studies indicate that even though the energy required to drive the RO system is a major contributor to the cost of fresh water production, there exists a tradeoff between minimum energy and minimum cost. An additional parametric study on the unit cost of energy is performed in order to explore future trends. The parametric study demonstrates how an increase in the unit cost of energy may shift the minimum cost designs to shift to more energy-efficient design scenarios.
The Effect of Carbon Nanotubes on the Natural Frequencies of Microcantilever Beams
Authors: Rokni D. T. Hossein , Milani Abbas S. , Seethaler Rudolf J. , Holzman Jonathan
Published: March 2011

In this study, the natural frequencies and mode shapes of carbon nanotube (CNT) reinforced polymer composite microcantilever beams are investigated by means of a micromechanical model and the three-dimensional finite element analysis. Microcantilever beams are made of Poly vinyl chloride (PVC) and reinforced with multi-wall carbon nanotubes (MWCNTs). MWCNTs can be distributed along the length/width/thickness of the nanocomposite beam. To validate the accuracy and effectiveness of the model, a direct comparison of results is made with an analytical solution for a test case. Next, various material types of the nanocomposite microcantilever beam are introduced and the effect of different distribution patterns and the weight-percents (wt%) of MWCNTs on the first six natural frequencies and mode shapes is found.
Meta Modeling Techniques and Optimal Design of Experiments for Transient Inverse Modeling Applications
Authors: Akkaram Srikanth , Agarwal Harish , Kale Amit , Wang Liping
Published: March 2011

The use of model-based simulation in engineering often necessitates the need to estimate model parameters based on physical experiments or field data. This class of problems is referred to as inverse problems in the literature and two significant challenges based on the application of inverse modeling technology to practical engineering problems are (a) computational cost of the inverse solution for complex transient simulation models that needed a long time to execute (b) ability of the instrumentation to shed light on the model parameters being estimated. This paper develops a methodology for the use of transient meta-modeling techniques for data matching applications to address the computational efficiency. The transient meta-models are constructed using the SVD/PCA approach to identify the key transient signature patterns from a dimension reduction perspective. Accuracy of the inverse modeling method with the direct simulation model and the meta-model are compared. The paper concludes with a methodology to optimally design an experiment and collect data to improve the nature of the inverse problem and the confidence with which the model parameters are estimated.
Retrognostics: Reverse Quality Management
Authors: Fukuda Shuichi
Published: March 2011

This paper points out that a great reduction of time and cost is possible by introducing PHM technology and by measuring quality from the viewpoint of the customer. Up to now, quality has been measured for verification at each manufacturing process unit to secure the quality of a final product required by design specifications. Therefore, it is nothing other than producer’s quality. But if customer’s quality or customer’s satifaction is fed back more straightforwardly, most of such verification procedures can be eliminated. This quality management is reversed from the traditional one, which is one way from upstream to downstream processes and is very much producer-centric. PHM technology plays a very important role for feeding back customer’s expectations and such a pattern classification mthods as Mahalanobis-Taguchi System will serve for realizing such a truly customer-driven quality management.
Challenge-Based Instruction and Its Application in a Course in Mechanisms and Related Courses
Authors: Freeman Robert A.
Published: March 2011

This paper discusses challenge based instruction (CBI) and associated materials developed for courses in Dynamics, Mechanisms, and Biomechanics. This effort is related to a College Cost Reduction and Access Act (CCRAA) grant from the Department of Education, and focuses primarily on the development of adaptive expertise. In science, technology, engineering, and math (STEM) fields the conventional approach is to teach for efficiency first and innovation only in the latter years of their curriculum. This focus on efficiency first can actually stifle attempts at innovation in later courses. One response to this issue is to change the way we teach. CBI, a form of inquiry based learning, can be simply thought of as teaching backwards. In this approach, a challenge is presented first, and the supporting theory (required to solve the challenge) second. Our implementation of CBI is built around the How People Learn (HPL) framework for effective learning environments and is realized and anchored by the STAR Legacy Cycle, as developed and fostered by the VaNTH (Vanderbilt-Northwestern-Texas-Harvard/MIT) NSF ERC for Bioengineering Educational Technologies. This cycle provides students the opportunity to immediately engage in creative activity in the “generate ideas” phase where they are asked what they think is important to know and do in solving the challenge. They are then led through a natural process of inquiry culminating in their “going public” with a solution to the challenge. Ideally, this approach develops both efficiency and innovation in parallel and results a student who is an “adaptive expert”. That is, one who can adapt their knowledge to new and novel situations outside of the context in which the knowledge was obtained.
Quantitative Assessment Framework for Product Value and Change Risk Analysis in Early Design Process
Authors: Oduncuoglu Arman , Grebici Khadidja , Thomson Vince
Published: March 2011

The ever changing trends in current markets along with customers’ rising demands for quality require many companies to make frequent changes in their products. In this paper, a framework for a comprehensive Decision Support System (DSS) is described and illustrated with a simple example of a thermo-flask. The DSS aims to obtain an optimal balance between customer and enterprise satisfaction by taking into account different design decision attributes: customer requirements, cost and design risk. The system allows the recalculation of cost, value, effort and risk when engineering change occurs during the creation of new design solutions. The proposed DSS integrates House of Quality (HOQ), Functional Analysis System Technique (FAST), risk assessment and change propagation analysis to provide a view of the design process from product attributes and design risk to cost and effort. The goal is to increase product knowledge in the early stages of design, to calculate the effects of engineering change, and to support design engineers in decision making.
Incorporating Security Considerations Into Optimal Product Architecture and Component Sharing Decision in Product Family Design
Authors: Rojas Arciniegas Alvaro J. , Kim Harrison M.
Published: March 2011

Multiple factors affect the decisions of selecting the appropriate components to share in product family design. Some of the challenges that the designers face are maintaining uniqueness and the desired performance in each variant while taking advantage of a common structure. In this paper, the sharing decision making process is analyzed for the case when a firm knows a priori that some of the components contain sensitive information that could be exposed to the user, third-party manufacturers, or undesired agents; thence, it is important to enclose it and protect it. Two important aspects to consider are defining the architecture of the product while protecting the sensitive information. This paper proposes tools to help the designers to identify components that are candidates for sharing among the family and finds the most desirable component arrangement that facilitates sharing while protecting the sensitive information that has been previously identified. The proposed framework is applied to three printers in which the architecture used for the ink cartridges and printheads are significantly different. Third-party manufacturers and remanufacturers offer their own alternatives for these subsystems (ink cartridges and printheads) since the customer for printer supplies is always looking for a cheaper alternative; meanwhile, the OEMs attempt to secure their products and retain their customers with original supplies. Having identified the sensitive components for each printer, the optimal clustering strategy is found, as well as the set of components that are candidates for sharing, according to their connectivity and the security considerations.
Realizing Orthogonal Motions With Wire Flexures Connected in Parallel
Authors: Su Hai-Jun , Tari Hafez
Published: March 2011

In this paper, we study the synthesis of wire flexures to achieve orthogonal motion by using a recently developed screw theory based approach. For a given desired mobility pattern, our goal is to find a system of wire flexures that are simply connected in parallel between the functional stage and the ground. It has been shown that a wire flexure is essentially a pure force or a line screw. An n dof motion space (allowable motion) is realizable if its reciprocal constraint space can be spanned by 6 – n line screws or forces. We first enumerate all possible one to five degree of motion spaces that are formed by motions along the coordinate axes attached on the functional stage. For each of these 34 motion spaces, we apply the screw theory approach to find its reciprocal force space as well as its rank. We conclude that 18 of them are realizable, 4 are realizable only when their pitches have opposite signs and 12 are not realizable. For each of these 34 cases, we provide an example showing the maximum number of independent wire flexures.
Dynamic Motion Generation for Redundant Systems Under External Constraints
Authors: Kim Joo H. , Abdel-Malek Karim , Xiang Yujiang , Yang Jingzhou James , Arora Jasbir S.
Published: March 2011

Dynamics of mechanical systems during motion usually involves reaction forces and moments due to the interaction with external objects or constraints from the environment. The problem of predicting the external reaction loads under rigid-body assumption has not been addressed extensively in the literature in terms of optimal motion planning and simulation. In this presentation, we propose a formulation of determining the external reaction loads for redundant systems motion planning. For dynamic equilibrium, the resultant reaction loads that include the effects of inertia, gravity, and general applied loads, are distributed to each contact points. Unknown reactions are determined along with the system configuration at each time step using iterative nonlinear optimization algorithm. The required actuator torques as well as the motion trajectories are obtained while satisfying given constraints. The formulation is applied to several example motions of multi-rigid-body systems such as a simple 3-degree-of-freedom welding manipulator and a highly articulated whole-body human mechanism. The example results are compared with the cases where the reactions are pre-assigned. The proposed formulation demonstrates realistic distribution of external reaction loads and the associated goal-oriented motions that are dynamically consistent.
Design and Fabrication of a Multi-Material Compliant Flapping Wing Drive Mechanism for Miniature Air Vehicles
Authors: Bejgerowski Wojciech , Gerdes John W. , Gupta Satyandra K. , Bruck Hugh A. , Wilkerson Stephen
Published: March 2011

Successful realization of a flapping wing micro air vehicle (MAV) requires development of a light weight drive mechanism converting the rotary motion of the motor into flapping motion of the wings. Low weight of the drive mechanism is required to maximize the payload and battery capacity. In order to make flapping wing MAVs attractive in search, rescue, and recovery missions, they should be disposable from the cost point of view. Injection molded compliant drive mechanisms are an attractive design option to satisfy the weight, efficiency and cost requirements. In the past, we have successfully used multi-piece molding to create mechanisms utilizing distributed compliance for smaller MAVs. However, as the size of the MAV increases, mechanisms with distributed compliance exhibit excessive deformation. Therefore localizing rather than distributing the compliance in the mechanism becomes a more attractive option. Local compliance can be realized through multimaterial designs. A multi-material injection molded mechanism additionally offers reduction in the number of parts. This paper describes an approach for determining the drive mechanism shape and size that meets both the functional design and multi-material molding requirements. The design generated by the approach described in this paper was utilized to realize a flapping wing MAV with significant enhancements in the payload capabilities.
The Engineering Design CK Theory: Contributions and Limits
Authors: Choulier Denis , Coatane´a Eric , Forest Joe¨lle
Published: March 2011

The CK theory of design created by Hatchuel and Weil has raised interest and controversies both in the academic and practitioners communities. After presenting the CK theory scope and focus, and the contributions claimed by the creators of the theory, we compare it to concepts and models more commonly used in traditional design approaches. It can be noticed that important concepts are ignored by the CK theory even if some of them are integrated in the research programs of Hatchuel, Weil and Le Masson. This initial analysis demonstrates that even in its scope, the CK theory appears incomplete to engineering design and does not consider important dimensions for the validity of the research program claimed. Then, we analyze from a critical viewpoint the foundations and hypotheses of the CK theory. Some propositions for improvement are set. Nevertheless, both the ability of CK theory to effectively assist and direct a creative process and, moreover, to organize the complete design and innovation processes are questioned. Finally, we conclude about the ambitious program and results claim by the authors of the CK theory.
Multi-Source Power Harvester for Cyborg Micro Air Vehicle
Authors: Tiwari Rashi , Schlichting Alex , Harris John Henry , Reissman Timothy , Garcia Ephrahim
Published: March 2011

The purpose of the reported research is to study the implementation of a sub-one gram, multisource energy harvester, for use on a Cyborg Micro Air Vehicle (CMAV). The CMAV would combine a biological flight platform with onboard communications, flight control, and power generation, providing a useful surveillance and reconnaissance vehicle. The biological platform chosen in this research is the Manduca sexta (Hawkmoth). A multisource energy harvester consisting of photovoltaic cells and a piezoceramic beam is discussed, enabling energy harvesting from vibration as well as ambient light. This paper discusses the results of those investigations and addresses the difficulties in creating the energy harvesting system.
A Computational Framework for Real-Time Unmanned Sea Surface Vehicle Motion Simulation
Authors: Thakur Atul , Gupta Satyandra K.
Published: March 2011

Unmanned Sea Surface Vehicle (USSV) motion simulation in time domain is an important component of USSV design and operation. This capability is needed for hull design, operator training, controller synthesis and testing. Many applications such as simulators for operator training require real-time performance. Traditional approaches based on strip theory, although fast, abstract hulls into slender bodies, making the simulation results insensitive to changes in geometry. Computational fluid dynamics (CFD) based approaches are accurate but very slow. Potential flow based approaches are sensitive to hull geometry and take lesser amount of time than CFD based approaches. The motion simulation using potential flow theory involves following four main operations: (1) computation of dynamic pressure head due to fluid flow around the hull under the ocean wave, (2) computation of wet surface, (3) computing surface integral of dynamic pressure head over wet surface, and (4) solving the rigid body dynamics equation. First three operations depend upon the boat geometry complexity and need to be performed at each time step, making the simulation run very slow. In this paper, we investigate the problem of model simplification for real-time simulation of USSV model in time domain using potential flow theory, with arbitrary geometry under ocean waves with inviscid and irrotational flow. Using clustering based simplification scheme and parallel computing we obtained real time simulation performance.
Damping Identification for Mistuned Blisks
Authors: Holland Darren E. , Epureanu Bogdan I. , Filippi Sergio
Published: March 2011

A novel structural damping identification method is presented. The approach is robust with respect to measurement noise and makes use of highly effective reduced-order-models (ROMs). Several different methods are currently available for damping identification. Most of these techniques can be grouped into two types based on the nature of the system information that is needed for the damping identification. The first type involves measuring damped eigenvalues and mode shapes, and does not require measurements of the system excitation. The second type involves measuring the forces applied to the system and constructing (full) frequency response functions. In contrast to existing techniques, the proposed method avoids complications involved in measuring damped modal characteristics or applied forces, while identifying structural damping only from displacement or velocity measurements. The focus of this work is identification of damping in systems with high modal density (such as cyclically symmetric systems) exemplified by blisks and bladed disks. First, a novel, general methodology for identifying (uniform) structural damping is presented. This method uses undamped tuned system mode shapes and a minimum of two measurements. Next, a more general methodology is formulated, which incorporates stiffness mistuning and uses ROMs for enhanced robustness and fast calculations. Validation of the damping identification is done by comparing the performance of the viscous damping method by Lee et al. with the proposed method. In Lee’s method, the complex frequency response function is used to determine a viscous damping matrix. This method is adjusted to identify structural damping where the damping matrix is now diagonal. For a low dimensional system and noiseless measurements, both Lee’s method and the proposed approach correctly identify the structural damping. Introducing measurement noise causes inaccuracies in the identification results obtained using Lee’s method, while the proposed method remains accurate. Next, two measurement filters are proposed to further increase the accuracy and robustness of the proposed damping identification by reducing the effect of measurement noise. The first filter applies to measurements which are approximately equal in amplitude and phase although they occur at different frequencies. The second filter removes measurements where the magnitude of the response is low. These filters are implemented for a complex validation structure: a one-piece bladed disk with stiffness mistuning. Simulated forced response measurements are generated by ANSYS and corrupted by noise. Next, measurements of the modal amplitudes and phases for the blisk are obtained through an elaborate and complex process of measurement point selection, mode selection, and data filtering similar to the one associated with mistuning identification. These filtered measurements are then shown to be accurate for use in the novel damping identification methodology.
Compensator Design for a MEMS Gyroscope With Quadratic Optimal Control
Authors: Cui Wei , Xue Wei , Chen Xiaolin
Published: March 2011

A number of control algorithms have been reported to adopt force balancing scheme into MEMS vibratory gyroscope systems. In practice, however, many algorithms are difficult to implement with electronic circuits. This paper designs and analyzes a lead compensator for a MEMS gyroscope via the Linear Quadratic Regulator (LQR) technique. LQR optimizes and balances the control effort and system response swiftness. Simulation shows the gyroscope achieves high linearity, wide dynamic range, and high robustness to fabrication uncertainties with this efficient compensator design. The closed-loop scale factor uniformity error is 0.7% under ±10% parameter perturbations. The compensator designed in this paper exhibits comparable outstanding performance compared to other reported control algorithms. The method reported in this paper is proved to be effective and can be used in a wide range of applications.
Adapting ADA Architectural Design Knowledge to Product Design: Groundwork for a Function Based Approach
Authors: Sangelkar Shraddha , McAdams Daniel A.
Published: March 2011

One in every seven Americans has some form of disability. The number of people with disabilities is expected to increase, perhaps significantly, over the foreseeable future. Nevertheless, persons with a disability remain underserved by consumer products. Product designers fail to design universal products primarily due to a lack of knowledge, tools, and experience with universal design. Though challenges to complete access remain, the design of universal architectural systems reflects a better codification of methods, guidelines, and knowledge than available to universal product design. This article reports research efforts to transfer elements of the design knowledge and tools from universal architectural design to universal product design. The research uses the International Classification of Functioning, Disability, and Health to formally describe user function, the Functional Basis to describe product function, and actionfunction diagrams as an analytical framework to explore the interaction between user activity, limitation, and product realization. The comparison of the universal and typical architectural systems reveal relevant design differences in specific parametric realization, morphology, and function. Of these differences, parametric was the most common with functional the least common. The user activities that most frequently result in a design change are reaching followed by maintaining body position. The comparison of architectural systems to consumer products noted a common trend of a functional design change made in result to the user activity of transferring oneself.
Minimum Reconfiguration for Fault Tolerant Manipulators
Authors: Abdi Hamid , Nahavandi Saeid
Published: March 2011

When a robotic manipulator is fault tolerant it is beneficial to study the configurations which tolerate non-catastrophic locked joint failures with a minimum relative change for the joint velocities. This problem is addressed using the properties of the condition number of the Jacobian matrix. The relationship between the faults within the joints of the manipulators and the condition number of the Jacobian matrix is used to introduce the optimal configurations for fault recovery. These optimum configurations require a minimum reconfiguration for fault tolerance of robotics manipulators. Then these configurations are studied for a 4-DOF planar manipulator to validate the proposed framework.
Risk Management in Product Design: Current State, Conceptual Model and Future Research
Authors: Oehmen Josef , Ben-Daya Mohammad , Seering Warren , Al-Salamah Muhammad
Published: March 2011

Risk management is an important element of product design. It helps to minimize the project- and product-related risks such as project budget and schedule overrun, or missing product cost and quality targets. Risk management is especially important for complex, international product design projects that involve a high degree of novel technology. This paper reviews the literature on risk management in product design. It examines the newly released international standard ISO 31000 “Risk management — Principles and guidelines” and explores its applicability to product design. The new standard consists of the seven process steps communication and consultation; establishing the context; risk identification; risk analysis; risk evaluation; risk treatment; and monitoring and review. A literature review reveals, among other findings, that the general ISO 31000 process model seems applicable to risk management in product design; the literature addresses different process elements to varying degrees, but none fully according to ISO recommendations; and that the integration of product design risk management with risk management of other disciplines, or between project and portfolio level in product design, is not well developed.
Automated Type and Modular Dimensional Synthesis of Planar Linkages
Authors: Pucheta Marti´n A. , Cardona Alberto
Published: March 2011

We present an automated method for type and dimensional synthesis of planar linkage mechanisms. In the kinematic problem, a graph representation called initial graph is given to the parts to move. The type synthesis stage consists of an exhaustive subgraph search of the initial graph inside the graphs taken from a previously enumerated atlas of mechanisms. Each alternative resulting from the type synthesis is dimensioned using the Precision Position Method and Genetic Algorithms: the closed-chain topology is decomposed into single-open chains of two and three links programmed as dyad and triad modules; these modules are executed to compute all the significant dimensions of the linkage. Using this type and dimensional synthesis method, a fast generation and evaluation of many mechanisms can be done in few minutes using a desktop personal computer. The enumeration of mechanisms for a path following task, including eight-bar solutions, illustrates the whole design process.
Modeling and Experimental Validation of DNA Motion During Electrophoresis
Authors: David Regis A. , Black Justin L. , Jensen Brian D. , Burnett Sandra H.
Published: March 2011

This paper describes the protocol and presents the results for DNA motion experiments using fabricated macroscale gel electrophoresis devices. Gel electrophoresis is a process used to separate/move DNA, RNA or protein molecules using an electric field through a gel matrix (electrolytic solution). In electrolytic solutions, the current conduction is due to a transport of ions (anions and cations). A better understanding of electrophoretic fundamentals allows for modeling the motion of DNA during electrophoresis. The model is validated through comparison with the experimental results. The model and experimental validation will be used to improve the process of cellular nanoinjection of DNA, currently in development in our lab.
Driving Function-Based Design With Outcome-Driven Inputs
Authors: Nagel Robert L. , Stone Robert B.
Published: March 2011

This paper presents research that integrates outcome-driven design methods with the more established function-based design methodologies. Outcome-driven design offers a more systematic approach to understanding the opportunity than the traditional and inconsistent means of gathering customer needs by exploring the reasons customers purchase products. These specific customer inputs are mapped to a process modeling technique to first broadly define how a customer will use a product. From this process model, a functional model can be extracted that abstractly captures what must happen within the product boundaries such that the product operates as intended to achieve the customers desired outcomes. An illustrative reverse engineering example is used to demonstrate the methodology. Preliminary case study validation results are discussed along with the conclusions and future work.
An Improved Kriging Assisted Multi-Objective Genetic Algorithm
Authors: Li Mian
Published: March 2011

Although Genetic Algorithms (GAs) and Multi-Objective Genetic Algorithms (MOGAs) have been widely used in engineering design optimization, the important challenge still faced by researchers in using these methods is their high computational cost due to the population-based nature of these methods. For these problems it is important to devise MOGAs that can significantly reduce the number of simulation calls compared to a conventional MOGA. We present an improved kriging assisted MOGA, called Circled Kriging MOGA (CK-MOGA), in which kriging metamodels are embedded within the computation procedure of a traditional MOGA. In the proposed approach, the decision as to whether the original simulation or its kriging metamodel should be used for evaluating an individual is based on a new objective switch criterion and an adaptive metamodeling technique. The effect of the possible estimated error from the metamodel is mitigated by applying the new switch criterion. Three numerical and engineering examples with different degrees of difficulty are used to illustrate applicability of the proposed approach. The results show that, on the average, CK-MOGA outperforms both a conventional MOGA and our developed Kriging MOGA in terms of the number of simulation calls.
A Hierarchical Modeling Scheme With Non Functional Requirements
Authors: Shankar Prabhu , Morkos Beshoy , Summers Joshua D.
Published: March 2011

This paper presents a sequence of multi domain matrix based modeling scheme, that includes non functional design requirements, to capture conceptual design information. The current matrix based modeling schemes are congruent to the steps followed in typical design processes but are limited to functional requirements. An industrial case study is analyzed to understand how and where the non functional requirements contribute to the design. It is observed from the case study that the non functional requirements drive the design decision process and constrains the way the product functionality is realized. Based on the observations made in the case study, a sequence of multiple domains is proposed: functional requirements to functions, functions to working principle, working principle to non functional requirements, non functional requirements to components, components to design parameters, design parameters to test measures and test measures to tests. This sequence is realized in a matrix based hierarchical modeling scheme, to capture the conceptual design information.
Examining the Effects of CAD Model Attributes on Alteration Time and Procedure
Authors: Johnson Michael D. , Diwakaran Ram Prasad
Published: March 2011

Modern computer-aided design (CAD) systems have significantly contributed to product development efficiency and cycle time reduction. CAD models can undergo several iterations through the development process; the use of CAD tools allows for these models to be quickly altered during these iterations. Altering existing CAD models can also reduce product development cycle-time by allowing for variants of these designs to be created quickly. These benefits require the reuse of CAD models to be quick and intuitive. This work examines the effects of several original and altered model variables (both attributes and derived quantities) and the perception of the original model on the speed with which the models were altered. Models created and altered using the SolidWorks and Pro|Engineer CAD platforms are examined and compared. It is shown that CAD models with fewer, complex features are altered more quickly. Models deemed as properly conveying design intent are also altered more quickly. Models perceived as having an intuitive feature order have a higher percentage of features being retained, but feature retention does not significantly affect alteration time. It is also shown that in the absence of incentives, improper modeling procedures are not corrected and increase during alteration.
Requirements and Data Content Evaluation of Industry In-House Data Management System
Authors: Morkos Beshoy , Joshi Shraddha , Summers Joshua D. , Mocko Gregory G.
Published: March 2011

This paper presents an industrial case study performed on an in-house developed data management system for an automation firm. This data management system has been in use and evolving over a span of fifteen years. To ensure the system is robust to withstand the future growth of the corporation, a study is done to identify deficiencies that may prohibit efficient large scale data management. Specifically, this case study focused on the means in which project requirements are managed and explored the issues of perceived utility in the system. Two major findings are presented: completion metrics are not consistent or expressive of the actual needs and there is no linking between the activities and the original client requirements. Thus, the results of the study were used to depict the potential vulnerability of such deficiencies.
Investigation of Algorithms for Analyzing Protein Internal Motion From Viewpoint of Robot Kinematics
Authors: Arikawa Keisuke
Published: March 2011

We investigate various algorithms for analyzing the characteristics of the internal motion of proteins based on the analogies between their kinematic structures and robotic mechanisms. First, we introduce an artificial simple protein model, planar main chain (PMC), composed of a planar serial link mechanism to investigate the algorithms. Then, we develop algorithms for analyzing the conformational fluctuations by applying the manipulability analysis of robot manipulators and control strategies for redundant manipulators. Next, we develop algorithms for analyzing the conformational deformation caused by the external forces and to evaluate the compliances of the specified parts of proteins. Finally, we show that the proposed algorithms developed by using PMC models are applicable for the three dimensional main chain structures of real proteins, and may be used to analyze their characteristics of the internal motion. We also reveal some preliminary simulation results of the analysis of a real protein.
Modelling and Simulation of a Flapping Wing Mechanism Driven by a Brushless Servo Motor
Authors: Xie Jin , Chen Yong
Published: March 2011

Flapping wing mechanism is designed to generate flapping motion for a micro air vehicle. Some issues concerning with the design and control of flapping wing mechanism are discussed in this paper. Firstly the problem of phase-lag between two wings is treated. To eliminate phase-lag, a method of modifying the design is proposed. Then, motion controlling of a flapping wing mechanism by means of changing the voltage inputted to servo motor is studied. Based on Lagrange’s formulation and Kirchhoff’s voltage law, motion equation for a servo motor coupled to flapping wing mechanism is established. Fourth-order Runge-Kutta method is employed to integrate this equation. For the purpose of finding the relationship between the flapping motion and the input voltage, a response diagram obtained from simulation of the system is utilized. A crucial voltage VC is obvious in the response diagram. If the input voltage is lower than VC, the mechanism will settle at its fixed point, only when the input voltage is higher than VC, can the mechanism work in order. Both to find all fixed points and to analyze their stability for a complex nonlinear dynamic system are difficult tasks. A numerical method to deal with these difficulties is proposed. The results of simulation also show that the flapping frequency increases with the increasing of input voltage provided that the input voltage is higher than VC.
Limitations to Function Structures: A Case Study in Morphing Airfoil Design
Authors: Schultz Jesse , Sen Chiradeep , Caldwell Benjamin , Mathieson James , Summers Joshua D. , Mocko Gregory M.
Published: March 2011

This paper presents an application of function structures in the design of single component morphing airfoils. A series of function structures are developed in an attempt to create an accurate model of a passively morphing airfoil. This paper describes each approach taken, while noting their modeling aspects that were successful or unsuccessful to identify representation features of existing function structure syntax and rules that relate to the usability of the models. System boundaries and definitions, function and flow definitions, carrier flows, and system state definitions are investigated. It was found that function structures in their current state, are incapable of accurately modeling the functionality of the shape changing aspect of a passively morphing airfoil. These limitations are identified and recommendations necessary to model artifacts similar to the morphing airfoil are presented. Finally, previous research efforts in the design of morphing airfoil technology are presented as solutions to certain key functions identified, thereby demonstrating the possible benefits of implementing function structures to this field.
Biologically Inspired Design: A Macrocognitive Account
Authors: Vattam Swaroop S. , Helms Michael , Goel Ashok K.
Published: March 2011

Biologically inspired engineering design is an approach to design that espouses the adaptation of functions and mechanisms in biological sciences to solve engineering design problems. We have conducted an in situ study of designers engaged in biologically inspired design. Based on this study we develop here a macrocognitive information-processing model of biologically inspired design. We also compare and contrast the model with other information-processing models of analogical design such as TRIZ, case-based design, and design patterns.
Navigating the Barriers to Interdisciplinary Design Education: Lessons Learned From the NSF Design Workshop Series
Authors: Simpson Timothy W. , Parkinson Matthew , Celento Dave , Chen Wei , McKenna Ann , Colgate Ed , Norman Don , Papalambros Panos , Gonzalez Richard , Roth Bernard , Leifer Larry
Published: March 2011

Evidence suggests that transformational innovation occurs at the intersection of multiple disciplines rather than isolated within them. Design—being both pervasive and inherently interdisciplinary—has the power to transcend many disciplines and help break down the departmental “silos” that hinder such collaborative efforts. Many universities are now struggling to embrace the curricular innovations that are necessary to achieve and sustain interdisciplinary education. Given the already packed undergraduate engineering curricula, several universities have started to offer new design programs that span several disciplines at the masters and doctoral levels. In this paper, we examine the five interdisciplinary graduate design programs offered by three different universities—University of Michigan, Northwestern University, and Stanford University—that hosted the NSF Design Workshop Series in 2008–2009. Collectively, these programs represent “solutions” that span a variety of graduate degree offerings that are available and provide examples of ways to successfully navigate the barriers and hurdles to interdisciplinary design education. A recap of the NSF Design Workshop Series is also provided along with recommendations from the workshops to foster discussion and provide directions for future work.
Design and Development Process for a Range Extended Split Parallel Hybrid Electric Vehicle
Authors: Gantt Lynn R. , Walsh Patrick M. , Nelson Douglas J.
Published: March 2011

The Hybrid Electric Vehicle Team of Virginia Tech (HEVT) is participating in the 2009–2011 EcoCAR: The NeXt Challenge Advanced Vehicle Technology Competition series organized by Argonne National Lab (ANL), and sponsored by General Motors Corporation (GM) and the U.S. Department of Energy (DOE). The goal of EcoCAR is for student engineers to take a GM-donated crossover SUV and re-engineer it to reduce greenhouse gas emissions and petroleum energy use, while maintaining performance, safety and consumer appeal. Following GM’s Vehicle Development Process (VDP), HEVT established team goals that meet or exceed the competition requirements for EcoCAR in the design of a plug-in range-extended hybrid electric vehicle. HEVT is split up into three subteams to complete the competition and meet the requirements of the vehicle development process. The Mechanical subteam is tasked with modifying and refining the Year 1 component specifications and designs for packaging in the vehicle. The Electrical subteam is tasked with implementing a safe high voltage system on the vehicle including the design and development of a Lithium Iron Phosphate (LiFePO4) energy storage subsystem (ESS) donated by A123 Systems. The Controls subteam is tasked with modeling the Vehicle Technical Specifications (VTS) so that the subteams can make intelligent design decisions. The Controls subteam also used a controller Hardware-In-the-Loop (HIL) simulation setup running a real-time vehicle model against the controller hardware to test the HEVT-designed Hybrid Vehicle Supervisory Controller (HVSC). The result of this design process is an Extended-Range Electric Vehicle (E-REV) that uses grid electric energy and E85 fuel for propulsion. The vehicle design is predicted to achieve an SAE J1711 utility factor-corrected fuel consumption of 2.9 l(ge)/100 km (82 mpgge) with an estimated all-electric range of 69 km (43 miles). Using corn-based E85 fuel in North America for the 2015 timeframe and an average North American electricity mix, the well-to-wheels petroleum energy use and greenhouse gas emissions are reduced by 90% and 30% respectively when compared to the stock vehicle: a 4-cylinder, gasoline-fueled Vue XE.