bluuebunny/crossref_metadata_2025 huggingface dataset:
Highly Integrated PiezoMEMS Enabled Millimeter-Scale Robotics
Authors: Pulskamp Jeffrey S. , Polcawich Ronald G. , Oldham Kenn
Published: July 2010

This report provides an overview of ongoing research at the U.S. Army Research Laboratory regarding the development of piezoelectric MEMS-enabled millimeter-scale robotics. Research topics include the development of enabling technologies for terrestrial locomotion, insect-inspired micro-flight, gecko-inspired reversible adhesives, and piezoelectric energy harvesting. The development of complementary lead zirconate titanate thin film MEMS devices, applicable to highly integrated millimeter-scale robotics, is also reviewed.
Pull-In Dynamics of Electrostatically Actuated Bistable Micro Beam
Authors: Krylov Slava , Dick Nir
Published: July 2010

Results of theoretical investigation of the transient dynamics of an initially curved electrostatically actuated clamped-clamped micro beam are presented. A reduced order model of the shallow Euler-Bernoulli arch developed using the Galerkin procedure with eigenmodes of a straight beam as a basis accounts for the distributed electrostatic and inertial loading, fringing electric fields and nonlinear squeeze film damping. Due to the unique combination of mechanical and electrostatic nonlinearities which is intrinsic in micro devices but is not encountered naturally in large-scale structures, the voltage-deflection characteristic of the sufficiently curved beam may have two maxima implying the existence of sequential mechanical (snap-through) and electrostatic (pull-in) instabilities. Phase plane analysis performed for the case of a suddenly applied electrostatic loading along with the simulation results show that critical voltages corresponding to the dynamic snap-through and pull-in instabilities are lower than their static counterparts while the minimal curvature required for the appearance of the dynamic snap-through is higher than in the static case. Clear functional advantages of this kind of structures, namely extended stable deflections and ability to tune the device frequencies in a very large range may result in improved performance of switches, inertial sensors and micromechanical non-volatile memory devices.
Singularity-Free Taskspace Optimization of 6-RSS Mechanisms
Authors: Li Hao , Zhang Yuru , Yang Yi
Published: July 2010

A method to calculate the volume of constant-orientation taskspace of parallel manipulators is developed and applied on the 6-RSS mechanism as an example. The taskspace is defined as a singularity-free reachable workspace. Quasi-singularity measure is used to measure the closeness to singular configurations and construct the quasi-singularity zone. Analyzed by DOE (Design of Experiment), effect weighs of design variables of a parallel manipulator are revealed and experiment results are applied in the optimization process. In order to obtain the maximum taskspace, the volume of the constant-orientation taskspace is optimized by a structured optimization process aided by iSIGHT-FD software. Finally, constant-orientation taskspace of greater volume is obtained.
Opportunities in Automotive Winter Testing
Authors: Nybacka Mikael
Published: July 2010

This paper aims to elaborate the challenges and possibilities in automotive winter testing in Sweden, in particular the use of fleet management framework and steering robots, which have shown to be an interesting area for future automotive winter testing. Data was collected from a number of interviews, workshops and surveys. Automotive manufacturers (OEMs), Tier 1 suppliers and service providers (e.g. test track owners and winter test entrepreneurs) contributed to the data collection. In general, service providers want to approach their customers in the value chain to provide new or extended services. From the data, the automotive industry is constantly pressed by shorter projects, fewer prototypes and the lack of state-of-the-art test methods. Service providers find the use of remote technologies, such as fleet management, an important part of their service, especially connected to the safety of test-drivers and overall test track safety. Service providers also consider further research in the area of fleet management and remote technologies as a base for future services. The automotive industry states that the possibility to replay the last run from logged data in the vehicle enhances the services. The use of steering robots during winter testing can provide an opportunity to run repeatable and standardized testing. However, the views here vary a lot between companies regarding the usability of the steering robots during winter testing. This indicates that further research on the issue of providing standardized winter testing is necessary. Work to extend a fleet management framework and a pre-study of the usability of steering robots in winter testing have begun, using the studies presented in this paper as a basis for this work.
Developing a Bio-Inspired Design Repository Using Ontologies
Authors: Wilson Jamal , Chang Patrick , Yim Sungshik , Rosen David W.
Published: July 2010

Efficient identification of relevant biological strategies to use in Conceptual Design is key to harnessing biological technologies in engineering. However, identification of these strategies is not straight forward. There are several approaches developed to aid in identifying these strategies, including searchable databases and functional keyword searches. Although these approaches offer access to these biological solutions, the generic keyword-based retrieval mechanisms utilized by these approaches often suffer from providing either too many and/or irrelevant results. In this paper, we present a design repository for storing and retrieving biological (and engineering) design strategies. The backbone of this repository is an ontology structuring information from the biological and engineering domains. This ontology is encoded using Description Logics, a subset of first-order logic that have been used for information modeling in several application areas, including engineering information management. Subsumption, an inference mechanism afforded in Description Logics, is used to retrieve relevant biological strategies from the repository. In this paper, we demonstrate that subsumption allows precise retrieval of relevant biological strategies from the repository.
Basic Characterization of a Linear Elastomer Actuator
Authors: Pagano Claudia , Malosio Matteo , Fassi Irene
Published: July 2010

Innovative types of actuators are required for several applications, especially in the field of medicine, robotics and micro-systems. In this context, Electroactive Polymers represent a promising group among all smart materials. They can change their dimensions and shape when an external voltage is applied, and their mechanical flexibility and ease of processing offer advantages over traditional electroactive materials expanding the options for different mechanical configurations. Dielectric elastomers are among the most promising EAPs for many applications, including actuators and sensors for the microfactory: they work in a dry environment, can achieve great deformations and support high voltage. They can be represented by a parallel plate capacitor: under an electric field the elastomer is squeezed in the thickness causing expansion in the transverse direction. Dielectric EAP actuators require large electric fields (hundreds of kV/mm) but can produce very large strain (up to 400%). Due to their unique properties and potential applications, in this paper the study of the electromechanical behaviour of a dielectric elastomer and a possible application related with the microfabrication of hybrid microsystem is presented.
Mobility Analysis of Robotic Mechanisms Based on Computer Algebra
Authors: Arikawa Keisuke
Published: July 2010

The Chebychev-Kutzbach-Gru¨bler criterion (CKG Criterion) is useful in evaluating the mobility of robotic mechanisms. However, it cannot correctly evaluate the mobility of some mechanisms (e.g., overconstrained mechanisms, mechanisms with Passive DOF, etc.). In this paper, we propose a more general method for automatically evaluating mobility, based on computer algebra. In this method, the constraints caused by links and joints are expressed as simultaneous algebraic equations (SAE), which is converted into a type of canonical form, constructed from special polynomials called the Gro¨bner Bases. The mobility can be then determined by checking the appearance sequence of the variables in the Gro¨bner Bases. The results are reliable because the method consists only of symbolic calculations and are free of numerical error problems. Moreover, the method is automatically applicable to spatial mechanisms containing various types of joints as no heuristics are required. We show the mobility analysis of three robotic mechanisms for which the CKG Criterion is not applicable, and show that the proposed method can correctly evaluate their mobility.
A Proposed Extendable Classification Scheme for Compliant Mechanisms
Authors: Olsen Brian M. , Hopkins Jonathan B. , Howell Larry L. , Magleby Spencer P. , Culpepper Martin L.
Published: July 2010

Limited resources are currently available to assist engineers in implementing compliant members into mechanical designs. As a result, engineers often have little to no direction incorporating compliance, though compliant mechanisms have characteristics that prove to be more advantageous in some circumstances. This paper proposes a classification scheme for compliant elements and mechanisms that can be used to compose a reference source intended to help engineers find existing compliant designs they can incorporate in their own designs. The classification scheme decomposes compliant mechanisms and elements of compliant mechanisms according to their respective functions.
Design Optimization of a Linear-Motion Large-Displacement Micro Mechanism for High Off-Axis Stiffness
Authors: Smith David G. , Larsen Gerrit T. , Howell Larry L.
Published: July 2010

This paper presents research on the large-displacement linear-motion planar compliant mechanism (X-Bob) specific to MEMS applications. The X-Bob’s potential for high off-axis stiffness makes it a strong candidate for precision MEMs applications. Understanding the characteristics and performance of the X-Bob can lead to the ability to modify it to fit specific applications. In this work, an X-Bob design is optimized for increased off-axis stiffness while maintaining a small footprint. The results are compared to previous X-Bob designs and to folded beam suspensions. Advantages and disadvantages of each design are explained.
Shape Commonalization to Develop Common Platform for Product Family
Authors: Chowdhury Sagar , Siddique Zahed
Published: July 2010

Current market place is highly competitive and frequently changing, to survive companies need to quickly respond to the customers’ requirements. This challenging situation demands a robust platform design and development process to produce variety of products in the shortest possible time. The common components for a set of similar products under a family can be grouped into a common platform. Development of product platform requires measuring the similarity among a set of products. This paper presents an approach to measure the similarity among a set of CAD models of products to develop a common product platform. The measured similarity of geometries can allow designers to identify components that have the potential to be included in the common platform. The degree of similarity is determined by extracting the information and developing a suitable commonality index for a set of CAD models. The commonality index values are then used to determine the common platform for a set of assembly products by developing and calculating the Average Assembly Platform index value. The overall approach is followed by two case studies: Cell Phone casing models and Vacuum Cleaner models.
Improving Multi-Objective Robust Optimization Under Interval Uncertainty Using Worst Possible Point Constraint Cuts
Authors: Hu W. , Li M. , Azarm S. , Al Hashimi S. , Almansoori A. , Al-Qasas N.
Published: July 2010

Many real-world engineering design optimization problems are multi-objective and have uncertainty in their parameters. For such problems it is useful to obtain design solutions that are both multi-objectively optimum and robust. A robust design is one whose objective and constraint function variations under uncertainty are within an acceptable range. While the literature reports on many techniques in robust optimization for single objective optimization problems, very few papers report on methods in robust optimization for multi-objective optimization problems. The Multi-Objective Robust Optimization (MORO) technique with interval uncertainty proposed in this paper is a significant improvement, with respect to computational effort, over a previously reported MORO technique. In the proposed technique, a master problem solves a relaxed optimization problem whose feasible domain is iteratively confined by constraint cuts determined by the solutions from a sub-problem. The proposed approach and the synergy between the master problem and sub-problem are demonstrated by three examples. The results obtained show a general agreement between the solutions from the proposed MORO and the previous MORO technique. Moreover, the number of function calls for obtaining solutions from the proposed technique is an order of magnitude less than that from the previous MORO technique.
Shape Memory Polymer Based Reconfigurable Compliant Mechanisms: An Exploration
Authors: Mankame Nilesh D. , Browne Alan L. , Saxena Anupam
Published: July 2010

This paper explores the concept of reconfigurable compliant mechanisms. We define these to be fully or partially compliant mechanisms whose performance can be modified after they have been fabricated. Specifically, we are interested in the nature and extent of in situ reconfigurability in compliant mechanisms. In other words, we seek to understand the range of performance that can be achieved by these mechanisms without requiring significant reassembly. The material properties such as the storage modulus of a newly studied class of materials — shape memory polymers — vary by over an order of magnitude over a temperature range of 20 – 50 C. These polymers also allow the fixing of moderate to large strains (20 – 75%) experienced at high temperatures for extended periods of time, while retaining the ability to remember their original shape when reheated to the same high temperatures. These two properties make shape memory polymers a natural candidate for the fabrication of reconfigurable compliant mechanisms. We explore various means for introducing reconfigurability in compliant mechanisms, and from these, select a subset that is suitable for in situ reconfiguration. Quasi-static nonlinear finite element simulations are used to study the change in performance due to reconfiguration of four fully compliant mechanisms made of a shape memory polymer. Preliminary results indicate that noticeable qualitative and quantitative changes in performance can be achieved by these mechanisms.
Reconfiguration Techniques and Geometric Constraints of Metamorphic Mechanisms
Authors: Zhang Liping , Dai Jian S. , Yang Ting-Li
Published: July 2010

This paper proposes a geometric way to generate metamorphic configurations and investigates metamorphic principles based on geometrized displacement group. Metamorphic reconfiguration techniques are revealed as the variations of kinematic joints, kinematic links and geometric orientation constraints particularly by examining the invariant configuration properties of a mechanism. The nature of all these configuration changes belongs to geometric constraint category. Metamorphic configuration units are proposed as the irreducible reconfiguration modules to envelop these reconfiguration techniques. It can self-reconfigure or be combined to generate metamorphosis. Moreover, the geometrized displacement group is lent to achieve a geometric representation for configuration modelling and further reconfiguration operations. Based on seting up kinematic group extended qualitatively according to its group structure, geometrized displacement group modelling is proposed for these identified metamorphic configuration units. The investigated group motion-matrix is an integration of its displacement group properties and kinematic extensions. Then defined geometric constraint relations and the proposed dependence rules lead to metamorphic principles. In this way, metamorphic process is mapped to matrix operations under group extensions and their compositions. Design examples and a metamorphic joint with six configurations are given to illustrate the feasibility of these metamorphic principles.
Seven-Position Synthesis of a Spatial Eight-Bar Linkage by Constraining a TRS Serial Chain
Authors: Soh Gim Song , McCarthy J. Michael
Published: July 2010

In this paper, we use seven-position synthesis to add four TS constraints to a TRS serial chain robot and obtain a two degree-of-freedom spatial eight-bar linkage. The TRS chain is an elbow manipulator, similar to a PUMA robot. We synthesize a TS dyad to connect the base of the robot to its forearm, and then we synthesize three TS dyads that connect the upper arm of the robot to its end-effector. The result is a two degree-of-freedom spatial eight-bar linkage that moves through seven prescribed positions. It consists of a TRST loop supporting a 3TS-RS platform, which we denote as a TS-TRS-3TS spatial linkage. We formulate and solve the design equations for the TS dyads, and analyze the resulting eight-bar linkage. An example demonstrates our results.
Selection of Part Orientation for Multi-Axis Hybrid Manufacturing Process
Authors: Ruan Jianzhong , Zhang Jun , Liou Frank
Published: July 2010

In regular 3 axis layered manufacturing processes, the build direction is fixed throughout the process. Multi-axis laser (more than 3-axis motion) deposition process, the orientation of the part can affect the non-support buildability in the multi-axis hybrid manufacturing process. However, each orientation that satisfies the buildability and other constraints may not be unique. In this case, the final optimal orientation is determined based on build time. The build time computation algorithm for multi-axis hybrid system is presented in this paper. To speed up the exhaustive search for the optimal orientation, a multi-stage algorithm is developed to reduce the search space.
A Testing Method and Cognitive Model of Human Diagram Understanding for Automating Design Sketch Recognition
Authors: Fuge Mark D. , Kara Levent Burak
Published: July 2010

Sketches, whether hand-drawn or computer generated, are a natural and integral part of the design process. Despite this fact, modern day computational design tools are ill-equipped to take full advantage of sketching input. The computational challenges of recognizing sketches are easily overcome by human visual recognition and much insight stands to be gained by emulating human cognitive processes. Creating robust, automated tools that overcome the ambiguity of sketching input would allow for advances not only in the practice of engineering design, but in the education of design itself. One first step toward the development of a robust sketching tool is to determine how humans interpret mechanical engineering diagrams. This paper presents two contributions toward the goal of an automated diagram understanding system. First, a method is presented to gain insight into human diagram recognition using techniques analogous to peripheral vision and human attention. Following this, a cognitive model of human diagram understanding is presented from which to further develop computational design tools. With this work, researchers should be able to (1) improve understanding of human diagram recognition and (2) use our model to emulate human diagram recognition in future computational design tools.
Selective Disassembly and Simultaneous End-of-Life Decision Making for Multiple Products
Authors: Behdad Sara , Kwak Minjung , Kim Harrison , Thurston Deborah
Published: July 2010

Environmental protection legislation, consumer interest in “green” products, a trend towards corporate responsibility and recognition of the potential profitability of salvaging operations have resulted in increased interest in product take-back. However, the cost-effectiveness of product take-back operations is hampered by many factors, including the high cost of disassembly and a widely varying feedstock of dissimilar products. Two types of decisions must be made; how to carry out the disassembly process in the most efficient manner to “mine” the value-added that is still embedded in the product, and then how to best utilize that value-added once it is recovered. This paper presents a method for making those decisions. The concept of a transition matrix is integrated with mixed integer linear programming to determine the extent to which products should be disassembled, and simultaneously determine the optimal end of life (EOL) strategy for each resultant component or subassembly. The main contribution of this paper is the simultaneous consideration of selective disassembly, multiple products, and the value added that remains in each component or subassembly. Shared disassembly operations and capacity limits are considered. An example using two cell phone products illustrates application of the model.
Developments Toward a Micro Bistable Aerial Platform: Analysis of the Quadrantal Bistable Mechanism
Authors: Mun˜oz Aaron A. , Lusk Craig P.
Published: July 2010

The Bistable Aerial Platform (BAP) functions as a switch in that its platform can lock in two positions, up or down. The Quadrantal Bistable Mechanism (QBM), the principle component of the BAP, is described in detail. A second component of the device, the Helico-Kinematic Platform (HKP), is still under investigation. It is anticipated that the model of the QBM, described here, will be combined with the HKP model, when complete, to form a full model of the Bistable Aerial Platform.
A Process-Centric Problem Formulation for Decision-Based Design
Authors: Thompson Stephanie C. , Paredis Christiaan J. J.
Published: July 2010

Although recent work in Decision-Based Design (DBD) recognizes the need for an enterprise perspective in which the expected net revenue is the primary driver of utility, for the overwhelming majority of contributions in the DBD literature, the emphasis in the problem formulation is exclusively on the design artifact. This formulation of DBD problems is too narrow in scope, in that the use of resources during the design and development phase is overlooked. This omission makes it impossible to consider tradeoffs between the design artifact and the design process. In this paper, we reformulate the DBD problem in terms of the design process rather than the artifact. This new formulation more accurately represents the tradeoffs under consideration in an enterprise context and simplifies to the traditional DBD formulation if design phase resource use is assumed to be negligible. As a first step towards establishing this new formulation, a simple example problem is introduced and solved. The example involves a choice between two concepts, with an option to perform an analysis to reduce the uncertainty. Although several simplifying assumptions are made in this work that are not likely to apply in practical design problems, the intent of this work is to qualitatively explore the impact of relaxing some of the assumptions made implicitly in previous work in DBD. These assumptions include ignoring the costs of the design phase as well as the assumption that the value of a particular information source is independent of the ability to gain additional information from subsequent analyses. Solving the design process decision problem in this manner confirms the intuition that an analysis is worth performing only when the cost is low, the quality is high, and there is significant overlap in the predicted utility of the two concepts. In addition, this new DBD formulation is compared to related work in information economics, and we show that the new DBD formulation provides a more comprehensive model of the problem when a sequence of information sources is available.
A New Sparse Grid Based Method for Uncertainty Propagation
Authors: Xiong Fenfen , Xiong Ying , Greene Steven , Chen Wei , Yang Shuxing
Published: July 2010

Although a variety of uncertainty propagation methods exist for estimating the statistical moments and the probability of failure in design under uncertainty, current methods suffer from their limitations in providing accurate and efficient solutions to high-dimension problems with interactions of random variables. A new sparse grid based uncertainty propagation method is proposed in this work to overcome this difficulty. The existing sparse grid technique, originally invented for numerical integration and interpolation, is extended to uncertainty propagation in the probabilistic domain. In particular, the concept of Sparse Grid Numerical Integration (SGNI) is extended for estimating the first two moments of performance in robust design, while the Sparse Grid Interpolation (SGI) is employed to determine failure probability by interpolating the limit-state function at the Most Probable Point (MPP) in reliability analysis. The proposed methods are demonstrated by several high-dimension mathematical examples with notable variate interactions and one complex multidisciplinary rocket design problem. Results show that the use of sparse grid methods works better than popular counterparts. Furthermore, the automatic sampling, special interpolation process, and dimension-adaptivity feature make SGI more flexible and efficient than using the uniform sample based metamodeling techniques.
Optimization of Tool Handle Shape for a Target User Population
Authors: Garneau Christopher J. , Parkinson Matthew B.
Published: July 2010

One goal of Designing for Human Variability (DfHV) is to optimize the interaction between user and device. Often, this interaction is dictated by the spatial dimensions or shape of the artifacts with which people interact. A novel approach that applies DfHV principles including virtual fitting trials to optimize the shape of an artifact is presented and applied to the design of a tool handle. By breaking the problem apart into discrete blocks, called the hand model and tool model, application of standard optimization techniques is facilitated. The benefits of the approach include the ability to consider handles with variable cross-sections and to systematically consider the effects of multiple sizes. The methodology presented here is configurable for any given population and may be applied to other DfHV design problems.
Genetic Evolution for the Development of Robust Artificial Neural Network Logic Gates
Authors: Roy Anthony M. , Antonsson Erik K. , Shapiro Andrew A.
Published: July 2010

Control tasks involving dramatic non-linearities, such as decision making, can be challenging for classical design methods. However, autonomous stochastic design methods have proved effective. In particular, Genetic Algorithms (GA) that create phenotypes by the application of genotypes comprising rules are robust and highly scalable. Such encodings are useful for complex applications such as artificial neural net design. This paper outlines an evolutionary algorithm that creates C++ programs which in turn create Artificial Neural Networks (ANNs) that can functionally perform as an exclusive-OR logic gate. Furthermore, the GAs are able to create scalable ANNs robust enough to feature redundancies that allow the network to function despite internal failures.
Enhancing Mechanical Engineering Distance Education Through IT-Enabled Remote Laboratories
Authors: Hyder Andrew C. , Thames J. Lane , Schaefer Dirk
Published: July 2010

The use of remotely operated laboratory experiments is gaining credibility to substitute traditional experimentation practices for distance learning students. Universities have been exploring this option to cater to the growing number of nontraditional students who are only able to participate in education remotely. In this paper the authors discuss how recent advances in robotic and network control have laid the foundation for which remote labs can be built and used as a novel educational tool. Models of how to implement remote laboratory experiments demonstrate the important considerations and best practices which would be addressed when developing an experiment. The consideration of network navigation is essential to foster the smooth connection between remote users and local equipment without inhibiting existing system functionality. Firewall communication through static and dynamic IP addresses must be delegated carefully while network and security administrators open channels for communication. Command and control interfaces can substantially reduce this complex orchestrate by serving as a dedicated web server. With the proper pedagogical and technical developments, remote laboratories will become a viable means to provide realistic experiences to anyone throughout the world.
On Hydrogen Bonds and Mobility of Protein Molecules
Authors: Shahbazi Zahra , Ilies¸ Horea T. , Kazerounian Kazem
Published: July 2010

Modeling protein molecules as kinematic chains provides the foundation for developing powerful approaches to the design, manipulation and fabrication of peptide based molecules and devices. Nevertheless, these models possess a high number of degrees of freedom (DOF) with considerable computational implications. On the other hand, real protein molecules appear to exhibits a much lower mobility during the folding process than what is suggested by existing kinematic models. The key contributor to the lower mobility of real proteins is the formation of Hydrogen bonds during the folding process. In this paper we explore the pivotal role of Hydrogen bonds in determining the structure and function of the proteins from the point of view of mechanical mobility. The existing geometric criteria on the formation of Hydrogen bonds are reviewed and a new set of geometric criteria are proposed. We show that the new criteria better correlate the number of predicted Hydrogen bonds with those established by biological principles than other existing criteria. Furthermore, we employ established tools in kinematics mobility analysis to evaluate the internal mobility of protein molecules, and to identify the rigid and flexible segments of the proteins. Our results show that the developed procedure significantly reduces the DOF of the protein models, with an average reduction of 94%. Such a dramatic reduction in the number of DOF can have has enormous computational implications in protein folding simulations.
Learning Geometric Design Knowledge From Conceptual Sketches and Its Utilization in Shape Creation and Optimization
Authors: Orbay Gunay , Kara Levent Burak
Published: July 2010

In current product design, significant effort is put into creating aesthetically pleasing product forms. Often times, the final shape evolves in time based on designers’ ideas externalized through early design activities primarily involving conceptual sketches. While designers negotiate and convey a multitude of different ideas through such informal activities, current computational tools are not well suited to work from such forms of information to leverage downstream design processes. As a result, many promising ideas either remain under-explored, or require restrictive added effort to be transformed into digital media. As one step toward alleviating this difficulty, we propose a new computational method for capturing and reusing knowledge regarding the shape of a developing design from designers’ hand-drawn conceptual sketches. At the heart of our approach is a geometric learning method that involves constructing a continuous space of meaningful shapes via a deformation analysis of the constituent exemplars. The computed design space serves as a medium for encoding designers’ shape preferences expressed through their sketches. With the proposed approach, designers can record desirable shape ideas in the form of raw sketches, while utilizing the accumulated information to create and explore novel shapes in the future. A key advantage of the proposed system is that it enables prescribed engineering and ergonomic criteria to be concurrently considered with form design, thus allowing such information to suitably guide conceptual design processes in a timely manner.
Development of a Changeable Airfoil Optimization Model for Use in the Multidisciplinary Design of Unmanned Aerial Vehicles
Authors: Ferguson Scott , Tilstra Andrew H. , Seepersad Carolyn C. , Wood Kristin L.
Published: July 2010

Complex systems need to perform in a variety of functional states and under varying operating conditions. Therefore, it is important to manage the different values of design variables associated with the operating states for each subsystem. The research presented in this paper uses multidisciplinary optimization (MDO) and changeable systems methods together in the design of a reconfigurable Unmanned Aerial Vehicle (UAV). MDO is a useful approach for designing a system that is composed of distinct disciplinary subsystems by managing the design variable coupling between the subsystem and system level optimization problems. Changeable design research addresses how changes in the physical configuration of products and systems can better meet distinct needs of different operating states. As a step towards the development of a realistic reconfigurable UAV optimization problem, this paper focuses on the performance advantage of using a changeable airfoil subsystem. Design principles from transformational design methods are used to develop concepts that determine how the design variables are allowed to change in the mathematical optimization problem. The performance of two changeable airfoil concepts is compared to a fixed airfoil design over two different missions that are defined by a sequence of mission segments. Determining the configurations of the static and changeable airfoils is accomplished using a genetic algorithm. Results from this study show that aircraft with changeable airfoils attain increased performance, and that the manner by which the system transforms is significant. For this reason, the changeable airfoil optimization developed in this paper is ready to be integrated into a complete MDO problem for the design of a reconfigurable UAV.
Product Platform Selection in Lower-Dimensional Manifold Spaces
Authors: Dabbeeru Madan Mohan , Mukerjee Amitabha
Published: July 2010

Product portfolios need to present the widest coverage of user requirements with minimal product diversity. User requirements may vary along multiple performance measures, comprising the objective space, whereas the design variables constitute the design space, which is usually far higher in dimensionality. Here we consider the set of possible performances of interest to the user, and use multi-objective optimization to identify the non-domination or the pareto-front. The designs lying along this front are mapped to the design space; we show that these “good designs” are often restricted to a much lower-dimensional manifold, resulting in significant conceptual and computational efficiency. These non-dominated designs are then clustered in the design space in an unsupervised manner to obtain candidate product groupings which the designer may inspect to arrive at portfolio decisions. With help of dimensionality reduction techniques, we show how these clusters in low-dimensional manifolds embedded in the high-dimensional design space. We demonstrate this process on two different designs (springs and electric motors), involving both continuous and discrete design variables.
Empirical Similarity Analysis Using Adaptive Trigonometric Functions
Authors: Tadepalli Srikanth , Wood Kristin L.
Published: July 2010

Similarity methods have been widely employed in engineering design and analysis to model and scale complex systems. The Empirical Similitude Method (ESM) is one such method based on the use of experimental data. Using a variant of the similitude process involving experimental data, we present in this paper, the use of advanced numerical approximations, trigonometric functions in particular to model and predict the performance of design artifacts. Specifically, an airfoil design is modeled, and the values of the drag coefficient are estimated based on the advanced ESM. Intermediate test specimens are used to correlate experimental data to produce the required prediction parameters. Mathematical development and error analysis are also elaborated by delving into continuity and adaptivity features of numerical algorithms.
Examining Potential Design Guidelines for Use in Fused Deposition Modeling to Reduce Build Time and Material Volume
Authors: Teitelbaum Gregory A. , Schmidt Linda C. , Goaer Yoann
Published: July 2010

This paper presents work to create a preliminary set of design guidelines for use in Fused Deposition Modeling (FDM). The experimentation uses build protocol for a Dimension SST Fused Deposition Modeler. Using simulation software known as Catalyst, build time and material volume characteristics of many components of varying size and complexity were calculated. A series of potential guidelines were independently applied to this same set of components. By comparing the new simulated data with the baseline, statistically significant improvements in these two metrics denoted those guidelines which passed a quantitative feasibility test. The results show that six design rules show universal advantage, with two more needing further examination. Future work will lie in examining the feasibility of implementing the changes proposed by the guidelines with respect to desired product functionality. Additionally, correlations related to the application of several guidelines simultaneously need to be determined.
Sketching in Design: Easily Influencing Behavior
Authors: Ruocco Ashley , Westmoreland Sophoria , Schmidt Linda C.
Published: July 2010

Many studies have shown the importance of sketching skill in engineering design, more specifically in the conceptual design phase. Yet, engineering students today clearly have a preference when it comes to design and sketching is not often included in their visual documentation tool kit. The reasons may be that first, today’s contemporary engineering course plan does not include a sketch training course leaving students feeling inadequate to the task. Secondly in such a demanding fast passed global economy, time is of the essence and tools such as CAD, Pro-E, and Inventor offer quick solutions to design problems. Overall students do not appear to appreciate the value of sketching in the design process. This must be changed. This paper presents the results of a study to intervene with the purpose of influencing student use of sketching during design in a senior capstone course at The University of Maryland. The students sketches are reviewed pre and post a specific lesson based on the importance of sketching in mechanical design. This sketching importance lesson changed the content of the sketches when compared to a control group.
An Effective Trilateration Algorithm for Mobile Robot Positioning Based on Multiple Reference Points
Authors: Zhou Yu
Published: July 2010

This paper presents a novel trilateration algorithm which estimates the position of a target object, such as a mobile robot, in a 2D or 3D space based on the simultaneous distance measurements from multiple reference points. The proposed algorithm is derived from the nonlinear least-squares formulation of trilateration, and provides a globally optimal position estimate from a general number of reference points and corresponding distance measurements. Using standard linear algebra techniques, the proposed algorithm has relatively low computational complexity and high operational robustness. Simulations have been conducted through representative examples to analyze the performance of the proposed trilateration algorithm in dealing with erroneous inputs of reference points and distance measurements. The results show that the proposed algorithm has lower systematic error and uncertainty in position estimation comparing with representative closed-form methods.
Design, Analysis, and Testing of a Metamorphic Gripper
Authors: Ziesmer Jacob A. , Voglewede Philip A.
Published: July 2010

This paper introduces a novel metamorphic gripper proposed as a step towards the solution of the bin picking problem. This gripper makes uses of multiple poses while maintaining contact with the part allowing for in-hand manipulation without the use of finger gaiting. The gripper is analyzed using classical techniques of degrees of freedom and adjacency matrices. This analysis allows for a basic understanding of the motion of the gripper.
Unified Mobility Identification and Rectification of Six-Bar Linkages
Authors: Ting Kwun-Lon , Wang Jun , Xue Changyu
Published: July 2010

This paper offers a unified method for a complete and unified treatment on the mobility identification and rectification of any planar and spherical six-bar linkages regardless the linkage type and the choice of the input, output, or fixed links. The method is based on how the joint rotation spaces of the four-bar loop and a five-bar loop in a Stephenson six-bar linkage interact each other. A Watt six-bar linkage is regarded as a special form of Stephenson six-bar linkage via the stretch and rotation of a four-bar loop. The paper offers simple explanation and geometric insights for the formation of branch (circuit), sub-branch, and order of motion of six-bar linkages. All typical mobility issues, including branch, sub-branch, and type of motion under any input condition can be identified and rectified with the proposed method. The method is suitable for automated computer-aided mobility identification. The applicability of the results to the mobility analysis of serially connected multiloop linkages is also discussed.
Assessing the Viability of an Interdisciplinary Design Engineering Program via a Branding Method
Authors: Elrod Cassandra C. , Grantham Lough Katie , Adams Kevin
Published: July 2010

This paper presents the brand status of the Interdisciplinary Engineering (IDE) degree program at Missouri University of Science and Technology (Missouri S&T), formerly the University of Missouri-Rolla (UMR). The IDE degree was founded in 2005 at UMR to meet the emerging need to provide considerable flexibility to students allowing them to construct programs of study in areas of interest while maintaining a solid and rigorous foundation in mechanics, thermal science, electrical networks and linear systems. Students are able to pursue studying the latest technological fields through a collection of “tracks” enabled by the flexibility of the curriculum. This modern degree program houses energetic motivated students interested in a variety of disciplines from product design and amusement park fundamentals to industrial automation and control. The first students graduated the IDE program in December 2007. This facilitated the evaluation of IDE’s current brand status, preparation of its future marketing plans, and sharing these findings with other universities interested in increasing student retention and broadening their demographic of engineering students. This paper presents the brand status of the IDE BS degree among prospective and current students, academic faculty, and industry and weighs it against the original implementation plan proposed in 2005 at the inception of the program at Missouri S&T. This brand management study provides the current perception of the new degree program and suggestions improving the perception IDE has as a field of engineering.
Bayesian Networks for Set-Based Collaborative Design
Authors: Shahan David , Seepersad Carolyn C.
Published: July 2010

A set-based approach to collaborative design is presented, in which Bayesian networks are used to represent promising regions of the design space. In collaborative design exploration, complex multilevel design problems are often decomposed into distributed subproblems that are linked by shared or coupled parameters. Collaborating designers often prefer conflicting values for these coupled parameters, resulting in incompatibilities that require substantial iteration to resolve, extending the design process lead time without guarantee of achieving a good design. In the proposed approach to collaborative design, each designer builds a locally developed Bayesian network that represents regions of interest in his design space. Then, these local networks are shared and combined with those of collaborating designers to promote more efficient local design space search that takes into account the interests of one’s collaborators. The proposed method has the potential to capture a designer’s preferences for arbitrarily shaped and potentially disconnected regions of the design space in order to identify compatible or conflicting preferences between collaborators and to facilitate a compromise if necessary. It also sets the stage for a flexible and concurrent design process with varying degrees of designer involvement that can support different designer strategies such as hill-climbing or region identification. The potential benefits are the capture of expert knowledge for future use as well as conflict identification and resolution. This paper presents an overview of the proposed method as well as an example implementation for the design of an unmanned aerial vehicle.
Static and Kinematic Analysis of a Planar Cable-Driven Flexible Endoscope
Authors: Munnae Jomkwun , McMurray Gary , Lipkin Harvey
Published: July 2010

Flexible endoscopes are mainly used for diagnostics and performing simple therapeutic tasks inside human cavities but are now becoming the key instrument for the incisionless surgery known as natural orifice transluminal endoscopic surgery (NOTES). Since the current endoscope technology gives limited maneuverability, dexterity, and functionality, a number of new endoscope designs have been proposed. Due to miniaturization, conduit, and actuation simplicity, many of the new designs rely on cable-actuating mechanisms similar to the current technology. Basic kinematical and static analyses for this device have not appeared in the literature. In this paper the articulated section of a planar cable-driven endoscope is modeled as a serial robot. The kinematic and static analyses for single-jointed and multi-jointed endoscope structures are performed to relate tip motion to the controlling inputs. Pre-tensioning cables increases the endoscope stiffness and extends its range of operation.
A Mass Sensing Technique for Electrostatically-Actuated MEMS
Authors: Khater Mahmoud E. , Abdel-Rahman Eihab M. , Nayfeh Ali H.
Published: July 2010

We propose a technique to increase the sensitivity and simplify the process of measuring minute masses using electrostatically-actuated MEMS. The sensor is composed of a cantilever beam connected to a rigid plate at its free end and coupled to an electrode underneath it. The method depends on the observation that the sensitivity of an electrostatically-actuated MEMS is highly enhanced when the driving voltage is close to the pull-in limit. We study two cases: the device actuated by a static force (DC voltage) and a dynamic force (combined AC and DC voltage). Sensitivity analysis is used to estimate the minimum detectable mass near static pull-in and near a dynamic pull-in point due to a cyclic-fold bifurcation.