bluuebunny/crossref_metadata_2025 huggingface dataset:
Sensor System Selection for Prognostics and Health Monitoring
Authors: Cheng Shunfeng , Azarian Michael , Pecht Michael
Published: July 2009

Data collection is an essential part of prognostics and health monitoring, and often requires the use of sensor systems to measure environmental and operational parameters. In this paper, the considerations for sensor system selection for prognostics and health monitoring implementation are discussed and some state-of-the-art sensor systems for prognostics are described. Finally, emerging trends in sensor system technologies are presented.
Coupled Lateral and Lane Separation Control for 2-D Vehicle Groups
Authors: Men Hao , Pochiraju Kishore
Published: July 2009

This paper describes control methodologies for a group of coordinated ground vehicles in which a single lead vehicle is assumed to be autonomous and the rest followers in a two-dimensional formation. The lead vehicle can be in any position of the group. Speed (throttle) and steering controllers are deployed in the follower vehicles which utilize only two parameters for position sensing. A minimum (safe) separation distance for vehicles following in lane (lane separation) and for those traveling abreast (lateral separation). Several sample missions, including lane following, square formations in right turns and lap runs are used to determine the performance of the controller for a four vehicle group. The variations in both lane and lateral separations during the mission are monitored as the primary measure of the controller performance.
Cooperative Towing With Multiple Robots
Authors: Fink Jonathan , Cheng Peng , Kumar Vijay
Published: July 2009

In this paper, we address the cooperative towing of payloads by multiple mobile robots in the plane. Robots are attached via cables to a planar object or a pallet carrying a payload. Coordinated motion by the robots allow the payload to be manipulated through a planar, warehouse-like environment. We formulate a quasi-static model for manipulation and derive equations of motion that yield the motion of the payload for a prescribed motion of the robots in the presence of dry friction and tension constraints. We present experimental and simulation results that demonstrate the basic concepts.
Parallel Robot Calibration Utilizing Adaptronic Joints
Authors: Last Philipp , Raatz Annika , Hesselbach Ju¨rgen , Pavlovic Nenad , Keimer Ralf
Published: July 2009

Model based geometric calibration is well known to be an efficient way to enhance absolute accuracy of robotic systems. Generally its application requires redundant measurements, which are achieved by external metrology equipment in most traditional calibration techniques. However, these methods are usually time-consuming, expensive and inconvenient. Thus, so-called self-calibration methods have achieved attention from researchers, which either use internal sensors or rely on mechanical constraints instead. In this paper a new self-calibration technique is presented for parallel robots which is motivated by the idea of constrained calibration. The new approach utilizes a special machine component called the adaptronic swivel joint in order to achieve the required redundant information. Compared to similar approaches it offers several advantages. The new calibration scheme is described and verified in simulation studies using a RRRRR-structure as an example.
Modeling an Enterprise Services Enabled Product Improvement Process for Military Vehicles
Authors: Gulledge Thomas R. , Hiroshige Scott , Iyer Raj , Johansson Mattias , Rose´n Jonas
Published: July 2009

The evolution of Enterprise Services is changing the approach for enabling Product Lifecycle Management (PLM) and Supply Chain Management (SCM). Enabling systems are migrating to process- and service-oriented solutions, requiring new approaches for architecting composite applications. This paper uses examples from our work to present the state-of-the art in architecting end-to-end solutions for delivering PLM and SCM capabilities from an Original Equipment Manufacturer (OEM) to the customer. The paper also demonstrates how emerging methodologies, methods, and tools are used to support the implementation of composite applications, as well as the limitations of working in a mixed legacy/modern environment during the lengthy transition period to the new service-oriented computing paradigm. The hypothesis of this paper is that design and supply chain integration is achievable through composite application design, development, and deployment. This paper discusses the design, development, and deployment of a composite application to address the product improvement process for military vehicles, and it lays the foundation for testing the hypothesis. Based on these initial analyses we conclude that the composite approach to PLM is not only feasible, but may provide the only practical solution (given current technologies) to a very complex supply chain information sharing problem.
Ontological Cross-Reducibility of Failure Theories for Composite Materials
Authors: Michopoulos J. G. , Iliopoulos A. P.
Published: July 2009

Failure criteria have a significant role in the design of composite structural systems. Often the questions of “which criterion is more physical” and “which criterion is the best” create uncertainty in the design decision making process. To underline the ill-posed nature of both of these questions in the present paper we are describing the initial steps of an effort to address two ontological characteristics of failure criteria as they are applicable to composite materials applications. The first characteristic is the non-objective nature of failure criteria and an informal description is provided. The second characteristic is an ontologically based cross-reducibility between criteria. To underline more formally this characteristic we utilize an ontology-based framework to clarify “how a criterion relates with another” in terms of its main semantic attributes. The non-physical nature of a theory is exposed when it is evaluated from the semantic view of a systemic perspective. The human role on the formation of any failure criterion is shown to have a foundationally subjective character, thus rendering the corresponding criterion as non-objective. In the context of the second effort, the creation of classification ontology in terms of the semantic projections of failure criteria in their structural heritage and usage is created. The common attributes of failure criteria are utilized to identify the bases of the attribute space that they can be ontologically classified. Web ontology software is utilized to aid the ontological construction process and the visual interpretation of the ontological context. The derived cross-reducibility suggests that failure theories are special reductions of one another.
Approximate Multi-Objective Optimization of Medical Foot Support
Authors: Miyake Shin-Ichiro , Arakawa Masao
Published: July 2009

Splayfoot seems not serious diseases. However, it cause fatigue in the daily life. It makes breakthrough in track athletic and many other fields in sports. In that sense, if we can solve these problems it might support daily life much comfortable especially for elder people. To support splayfoot, there are some commercial ones. But they just add small amount of support and not made up for each person. Besides, when the height of support is not suitable for patients, it sometimes make situation worse. We have tried it and measured by using myoelectric potential measurement, and see differences of three patients. Even if we use the same commercial support its effectiveness differs to each other and sometimes it make worse. Physical therapists make foot support for each patient but they make them owing to their experience. There are studies on the positions of bone of foot and its portrait of the desired positions has been reported by medical doctors. One of them is called Mizuno [1973] standard. In this study, we tried to design foot support aiming to make portrait of this standard. For that purpose, we use approximate multi-objective optimization using Radial Basis Function network. First, we make some support and try to find characteristic points of spline function. These processes have been measured by X-ray and calculated portraits for each X-ray digital image. Then, we have gone through multi-objective optimization and design a foot support for one patient and made it by hard sponge. We measured it by X-ray again to make sure that the portrait has been done in acceptable position. For validation, we use electromyography again. As a result the foot support by the proposed method shows the maximum reduction in integral of myoelastic. This shows the effectiveness of the proposed method.
Data-Driven Characterization of Composites Based on Virtual Deterministic and Noisy Multiaxial Data
Authors: Michopoulos J. G. , Furukawa T. , Lambrakos S. G.
Published: July 2009

This paper presents an inverse methodology capable of identifying the elastic moduli of laminated composites from both deterministic and noisy data originating from virtual multiaxial tests. Unlike the conventional uniaxial characterization of materials, the methodology exploits the energy balance between the increment of external work and the corresponding increment of strain energy. It then formulates an overdetermined system of linear equations that are solved using Singular Value Decomposition (SVD) to compute the associated pseudoinverse array. The proposed methodology further controls the multiaxial testing machine by utilizing performance measures of the SVD process to construct objective functions that are maximized in order to compute loading path design variables. Numerical examples investigate the significance, robustness and efficiency of the proposed methodology. Deterministic and noisy data are synthesized in order to demonstrate the applicability of the technique with respect to realistic characterization problems. The effect of noisy data in the characterization process has been examined in a manner that leads to a demonstration of the practicality of the approach.
Computer Aided Synthesis of Rational Motion Under Kinematic Constraints of Spatial SS Open Chains
Authors: Purwar Anurag , Jin Zhe , Ge Q. J.
Published: July 2009

In this paper, we study the problem of rational motion interpolation under kinematic constraints of spatial SS open chains. The objective is to synthesize a smooth rational motion that interpolates a given set of end effector positions and satisfies the kinematic constraints imposed by spatial SS open chains. The kinematic constraints under consideration define a constraint manifold representing all the positions available to the end effector. By choosing dual quaternion representation for the displacement of the end effector, the problem is reduced to designing a smooth curve in the space of dual quaternions that is constrained to lie inside the constraint manifold of the spatial SS open chain. An iterative numerical algorithm is presented that solves this problem effectively. The results presented in this paper are extension of our previous work on the synthesis of piecewise rational planar and spherical motions for open and closed chains under kinematic constraints.
A Parallel Cable-Driven Crane for Scara-Motions
Authors: Krut Se´bastien , Ramdani Nacim , Gouttefarde Marc , Company Olivier , Pierrot Franc¸ois
Published: July 2009

This paper introduces a lower mobility parallel kinematic crane able to generate Scara motions (three translations and one rotation about a vertical axis). A crane is an underconstrained cable robot: it requires gravity acting on the traveling plate in order to tense the cables. The proposed crane can resist, to a certain extent, against outside forces and torques in all directions of the 6-dimensional task space. This feature results from the use of pairs of cables linking the actuators and the traveling plate. The proposed crane is derived from the I4 parallel robot. Thus, its traveling plate is articulated which provides a wide range of orientation. It is hyperstatic in the sense that one of the eight cables can be removed while keeping the same kinematic relationships. However, for symmetry reasons all the eight cables are kept (this feature is interesting in case of a cable breakdown). The input/output geometrical and kinematic models required for control are derived. Then, the cables tensions are obtained enabling the determination of the static workspace defined as the domain of reachable space where the cables remain taut under the action of gravity.
Towards Adaptable Architecture
Authors: Chmarra Magdalena K. , Arts Lieke , Tomiyama Tetsuo
Published: July 2009

There is a need for products that can automatically adapt to various environmental and working conditions. Since a standard theoretical framework for designing such adaptable products is not yet established, only few rules, generalized methods, software tools, and guidelines for design for adaptability can be found in literature. The goal of this paper is to address issues associated with designing adaptable product architecture and to propose a first step to develop methods and tools to deal with these issues. The paper first gives various definitions and an overview of product adaptability. Then it discusses adaptable product architectures, external conditions, and customer needs that are crucial aspects in designing adaptable products. The research proposes a scheme of an adaptable product that can constitute part of a formalized design method for adaptability. Finally, it illustrates the design choices that should be made to arrive at an adaptable product architecture.
Case Study Method for Design Research: A Justification
Authors: Teegavarapu Sudhakar , Summers Joshua D. , Mocko Gregory M.
Published: July 2009

Case studies are used in design research to analyze a phenomenon, to generate hypotheses, and to validate a method. Though they are used extensively, there appears to be no accepted systematic case study method used by design researchers. Considering its nature and objectives, the case study method could be considered as a suitable method for conducting design research. Many times, design researchers have to confront questions about the validity of using case studies and their results. The objective of this paper is to present a brief overview of case study method, compare it with other qualitative and quantitative research methods, and study the merits and limitations of using the same in design research. Requirements are derived from the general characteristics of design research. Four popular research strategies are evaluated with respect to the requirements. A preliminary benchmark study suggests that case study method is a suitable method for conducting design research.
A Lumped-Model Based Building-Block Concatenation for a Conceptual Compliant Mechanism Synthesis
Authors: Krishnan Girish , Kim Charles , Kota Sridhar
Published: July 2009

Present building-block synthesis techniques for compliant mechanisms [4–7] account for the kinematic behavior of the mechanism alone, leaving the stiffness, manufacturability and mechanical efficiency to be determined by the shape-size optimization process. In this effort, we aim to generate practical and feasible conceptual designs by designing for kinematics and stiffness simultaneously. To enable this, we use a lumped spring-lever model, which intuitively characterizes the stiffness and the kinematics of a deformable-complaint building block with distinct input and output points. This model aids in the understanding of how the stiffness and the kinematics of building blocks combine when concatenated to form a mechanism. We use this understanding to synthesize compliant mechanisms by combining building blocks of known motion characteristics. A simple compliant-dyad building block is characterized for its lumped values of stiffness and kinematics. The concatenation of these dyad-building blocks is solved in detail, and guidelines for conceptual synthesis are proposed. Two practical examples are solved; a motion amplifier for a piezo-stack and a compliant energy storage mechanism for a staple-gun. The conceptual designs obtained from this approach are very close to the kinematic and the stiffness requirements of the application, thus minimizing the role of shape and size optimization to achieve the problem specification. The model, when extended to higher dimensions may be used to solve for precision positioning and other applications.
Analysis of the Information Environment in the Context of Target and Requirements Management in the Automotive Industry
Authors: Ilie Delia , Fischer Florian , Lindemann Udo
Published: July 2009

The development of highly complex products requires an increase of knowledge and an optimized flow of information. During the development process information is generated, changed, propagated, and documented. Hence many documents are generated and various systems are established. Yet, during the development process these documents are not adhered to and not consistently updated such as the systems that are not upgraded. The result is a discontinuous information environment, consisting of a variety of redundant and inconsistent information documented in numerous information systems. Within the scope of this paper the analysis of an information environment in the context of target and requirements management performed in the automotive industry is presented, showing the insufficiencies of this environment, the causes of these defects and their impacts and consequences on the development process. Further, this study brings forward new insights regarding the different characters of the information in the workflow and thus giving the possibility to make the information well-defined by introducing so-called distinctive configuration characteristics (DCC). These attributes and their parameter value are presented and discussed in the face of a proposal of restructuring the information consistently regarding a new configuration of the information environment.
Customizing Products Using Functional Component Matrices
Authors: Kamyab Ali , Lewis Kemper E.
Published: July 2009

Modern design methodologies have used Function Component Matrices in a variety of different ways in order to support various facets of an engineering design process. The mapping of functions to components can be used to model and capture the dependencies and relationships that exist. This process is accomplished by breaking down complicated functions into smaller, easier to understand functions. This decomposition allows engineers to get a better understanding for how a change in each component within a product will affect the overall operation of the product. Being able to recognize the impact of the propagation of a sub-function change will give designers a better understanding of the flexibility (or lack thereof) of choices they have when designing a product for customization. In turn they can be used to inform the consumer regarding the consequences their customization choices can have on the final product. This paper discusses how a Functional Component Matrix (FCM) can be used to assist in this process of product customization and understanding change propagation.
Active Vibration Control of a 3-PRR Flexible Parallel Manipulator With PZT Actuators and Sensors
Authors: Zhang Xuping , Mills James K. , Cleghorn William L.
Published: July 2009

This paper presents an experimental study on active vibration control of a moving 3-PRR parallel manipulator with three flexible intermediate links, with bonded lead zirconate titanate (PZT) actuators and sensors. Experimental modal tests are conducted to identify structural vibration mode shapes and natural frequencies used. These modal tests provide guidance to design the filter and determine the location of PZT transducers. A PZT actuator controller is developed based on strain rate feedback (SRF) control. A state-space model is formulated with the control input voltage applied to PZT actuators, and output generated from PZT sensors. Then, the design of an optimal active vibration controller is presented based on SRF for the parallel manipulator with flexible links with multiple bonded PZT transducers. Active vibration control experiments are conducted to demonstrate that the proposed active vibration control strategy is effective. Power spectral density (PSD) plots of vibrations illustrate that the structural vibration of flexible links is reduced effectively when the proposed vibration control strategy is employed.
Product Data Management in Undergraduate Education
Authors: Caldwell Benjamin , Mocko Gregory M.
Published: July 2009

Product Data Management (PDM) systems provide a means for sharing and controlling documents in collaborative product development. PDM are used in industrial applications for long-term archival of product information, to enhance collaboration and communication throughout the design process, support distributed design teams through advanced document sharing, track changes in product information, and control design documents ranging from requirements information to CAD. However, undergraduate mechanical engineering students typically graduate with limited or no exposure to PDM systems. This paper investigates the benefits and challenges associated with modern PDM systems. Moreover, the need for PDM systems in undergraduate education are discussed and means for integrating this technology is presented. A survey of engineering institutions in the U.S. is completed to understand the current usage in academic settings. Specifically, this paper describes appropriate course and project support of PDM systems.
Aligning Molecular Attachment Sites in Single Molecule Force Spectroscopy Measurements
Authors: Rivera Monica , Lee Whasil , Marszalek Piotr E. , Cole Daniel G. , Clark Robert L.
Published: July 2009

In atomic force microscopy (AFM) -based single molecule force spectroscopy, it is assumed that the pulling angle is negligible and that the force applied to the molecule is equivalent to the force measured by the instrument. Although this assumption may hold for flexible, compact molecules, studies have shown that it may not be appropriate for fairly rigid molecules, where measured forces can be a fraction of the actual values experienced by the molecule. Previously, we have proposed a method to align a molecule’s substrate and cantilever attachment sites and tested it in a simulated environment. Here we continue our work and test the alignment program in an experimental environment. In this paper we demonstrate that circling-induced force fluctuations are the result of stretching and relaxing a tethered molecule and we present the results of an alignment trial. Combined, these preliminary results demonstrate the feasibility of the alignment program and are a promising step towards correcting pulling geometry errors in single molecule force spectroscopy studies.
Fuel Efficiency Comparison Between a Conventional and a Hybrid Vehicle Using a Model Based on MATLAB/Simulink and ADAMS
Authors: Fan Brian S. , Khajepour Amir , Kazerani Mehrdad
Published: July 2009

Recent development of hybrid vehicles in the automotive industry has demonstrated the capability of reducing fuel consumption while maintaining vehicle performance. The purpose of this paper is to present a hybrid vehicle model created in MATLAB and ADAMS, and its fuel economy improvement over a conventional vehicle system. The hybrid vehicle model discussed in this paper utilizes the Honda IMA (Integrated Motor Assist) architecture. The powertrain components’ power output calculation and the control logic were modeled in MATLAB/Simulink, while the mechanical inertial components were modeled in ADAMS. Communication between MATLAB and ADAMS was established by ADAMS/Controls. The vehicle model created using MATLAB and ADAMS provides a more accurate, more realistic, and a highly flexible simulation platform. In order to evaluate the accuracy of the MATLAB/ADAMS hybrid vehicle model, simulation results were compared to the published data of ADVISOR. Fuel economy of hybrid and conventional vehicle models were compared using the EPA New York City Cycle (NYCC) and the Highway Fuel Economy Cycle (HWFET). The hybrid vehicle demonstrated 8.9% and 14.3% fuel economy improvement over the conventional vehicle model for the NYCC and HWFET drive cycles, respectively. The MATLAB/ADAMS vehicle model presented in this paper, demonstrated the fuel economy advantage of the hybrid vehicle over the conventional vehicle model, while offering a simulation platform that is modular, flexible, and can be conveniently modified to create different types of vehicle models.
Project First: A Case Study in Mechatronics Course Design
Authors: Fiene Jonathan P. , Yim Mark
Published: July 2009

In many project-based mechatronic courses, the project is either a tangential part of the course or a kit is given to the students (e.g. parts of a mobile base for a robot) which they then assemble and modify as necessary. In contrast to these typical approaches, we present the design of a mechatronics course wherein the semester project pre-determines the various lab activities, which then define the ordering and content of the classroom lectures. As such, the project is the core focus of the course, and the supplied components are kept to a minimum in order to maximize the solution space and student creativity. Putting such a strong emphasis on the project requires that significant effort is invested early to select a suitable project for the semester, but once that choice is made, the remainder of the content essentially fills in automatically. In addition to the case study, we present more general rules and context which can be helpful in choosing a project and fostering a strong peer-assisted learning culture.
An Iterative Approach for Steady State Handling Analysis of Vehicles
Authors: Karogal Indrasen , Ayalew Beshah , Law E. Harry
Published: July 2009

In this paper, we present an iterative approach for analyzing the steady state handling behavior of a two-axled vehicle. This approach computes lateral forces iteratively from two separate submodels. The first submodel is an appropriate tire model that computes per wheel lateral forces as functions of slip angles, from formulations preferably expressed in a non-dimensional format. The second is a lateral weight transfer submodel that computes per-axle lateral force contributions for a given lateral acceleration. The combination then allows for the estimation of the required steer angles for the prevailing lateral acceleration. Subsequent corrections are then applied to take into account steer effects such as roll steer, lateral force compliance steer and aligning moment compliance steer. The usefulness of the approach is demonstrated by comparing simulation results with test data for a small passenger car.
A Virtual Harp for Therapy in an Augmented Reality Environment
Authors: Taylor Tanasha , Smith Shana , Palmerius Karljohan L.
Published: July 2009

The goal of this research study was to develop a music therapy tool using a computer-generated harp which could provide users with visual, audio, and haptic feedback during interaction with the virtual instrument. Realistic 3D visual and haptic feedback was provided through immersion in a portable augmented reality-based system composed of a video see-through head mounted display (HMD) and a Sensable Phantom Omni haptic device. Users play the virtual harp by using the Phantom Omni haptic device to pluck or strum the strings of the harp. Users can also freely move the harp in the augmented reality environment to provide a more realistic experience, similar to that of playing a traditional musical instrument. The system will be used to provide interactive musical experiences and to develop motor skills among individuals with disabilities through music therapy. A virtual therapist feature was developed which can be used by a therapist without musical knowledge to observe a user during therapy exercises or by a user to engage in self-motivated therapy exercises outside the therapy room. With the virtual therapy feature, users can follow a simple pre-determined sequence of notes using color-coded strings. User testing was completed to study usability, therapeutic effectiveness, and patients’ therapy motivation.
Personal Cognitive Characteristics in Affordance Perception: The User Activity Case Study in a Building Lobby
Authors: Kim Y. S. , Jeong J. Y. , Kim M. K. , Lee S. W.
Published: July 2009

User activities in performing tasks are influenced by the way the user perceives the related surrounding context and environment and determined with user judgment preferences. Physical environment structures afford user activities when these are perceived. Thus, this paper addresses how user activities and perceived affordances are different reflecting personal creativity modes, which are determined by factual-intuitive perception inclination and subjective-objective decision preferences as well as introverted-extroverted nature. To design-in various affordance features for diverse users in varying contexts, understanding on relations between user personal characteristics and affordance perception would be helpful. We conducted a case study in a public space — building lobby — used by many general people. User activities and behaviors were analyzed in several specific tasks given to twenty students in the lobby of a building they have never been to before. The tasks were devised so that various affordance features could be relevant while eliminating other factors affecting the affordance perception than those due to user personal characteristics. User activities can be classified into several different groups for each task based on affordance features involved in their activities. These user activity differences are then compared with their personal creativity modes. For user of less common activities for some tasks, relevant personal cognitive characteristics have been identified.
Three-Dimensional Holographic Lithography Using a Spatial Light Modulator
Authors: Jenness Nathan J. , Cole Daniel G. , Clark Robert L.
Published: July 2009

In this paper we present a lithographic process with the ability to automatically translate and arbitrarily position three-dimensional (3D) computer-generated patterns through the use of phase holograms. This method, dynamic maskless holographic lithography (DMHL), advances current photo-directed patterning and functionalization capabilities by expanding the capability to manipulate light in real-time without the use of expensive fixed masks. The system could be used for large-scale parallel manufacturing over larger areas and for point specific serial fabrication, interrogation, and metrology. The use of coherent illumination allows for the direct creation of 3D patterns of light for lithography as opposed to the mechanical stage, layer-by-layer 3D fabrication approach typical of direct-write systems. Extrinsic control over interfacial properties will provide a method for addressing aqueous phase bionanotechnolgy experimental systems in which detection, separation, transport, and handling are vital.
Mobility Criteria of Planar Single-Loop N-Bar Chains With Prismatic Joints
Authors: Ting Kwun-Lon , Xue Changyu , Wang Jun , Currie Kenneth R.
Published: July 2009

The paper offers an extension of Ting’s rotatability laws to N-bar chains connected by revolute and prismatic joints. The extension is based on the principle that a prismatic joint may be regarded as a revolute joint located at infinity in the direction normal to the path of the slider. The extension provides a consistent method to understand all aspects of linkage rotatability disregarding the existence of prismatic joints. The simplicity and consistency of its applications is demonstrated with examples.
An Investigation on the Profile of Microlens by the Thermal Reflow Process Due to Surface Tension and Gravity
Authors: Tsai Jhy-Cherng , Hsu Yong-Sung
Published: July 2009

Microlens and its mold fabricated by thermal reflow using photoresist have been widely used for forming patterns in different scales. When the photoresist solidifies from melting condition, for example by the reflow process, its profile is formed based on the balance between surface tension and gravity. This research is aimed to investigate the influence of surface tension and gravity on the profile of microlens in thermal reflow process. Theoretical analysis based on the interaction between surface tension and gravity of liquid droplet is first investigated. The result showed that the height to diameter ratio (h/D), or the sag ratio, of the liquid droplet is affected by the Bond number (Bo), a number defined as the ratio of gravity to surface tension. The sag ratio is not sensitive to Bo when Bo is small but the ratio decreases as Bo increases if Bo is over the critical number. Based on the analysis, the critical number for the AZ4620 photoresist on a silicon substrate is 1, corresponding to the critical radius of droplet R = 2,500μm. When the size of the droplet is less then the critical size, the profile is mainly controlled by the surface tension and thus the sag ratio is about the same regardless the size. The profile, in contrast, is highly affected by the gravity if the size of the droplet is larger then the critical size. The sag ratio decreases exponentially with respect to Bo in this case. Experiments are also designed and conducted to verify the analysis. Experimental result showed that the sag ratio of the photoresist reduces to 0.065 from 0.095 when Bo increases from 0.0048 to 0.192. The results showed that the trend is consistent to the theoretical model.
A Web-Based Environment for Documentation and Sharing of Engineering Design Knowledge
Authors: Rockwell Justin A. , Witherell Paul , Fernandes Rui , Grosse Ian , Krishnamurty Sundar , Wileden Jack
Published: July 2009

This paper presents the foundation for a collaborative Web-based environment for improving communication by formally defining a platform for documentation and sharing of engineering design knowledge throughout the entire design process. In this work an ontological structure is utilized to concisely define a set of individual engineering concepts. This set of modular ontologies link together to create a flexible, yet consistent, product development knowledge-base. The resulting infrastructure uniquely enables the information stored within the knowledge-base to be readily inspectable and computable, thus allowing for design tools that reason on the information to assist designers and automate design processes. A case study of the structural optimization of a transfer plate for an aerospace circuit breaker is presented to demonstrate implementation and usefulness of the knowledge framework. The results indicate that the ontological knowledge-base can be used to prompt engineers to document important product development information, increase understanding of the design process, provide a means to intuitively retrieve information, and seamlessly access distributed information.
A Fast and Efficient Compact Packing Algorithm for Free-Form Objects
Authors: Tiwari Santosh , Fadel Georges , Fenyes Peter
Published: July 2009

In this paper, a compact packing algorithm for the placement of objects inside a container is described. The proposed packing algorithm packs three-dimensional free-form objects inside an arbitrary enclosure such that the packing efficiency is maximized. The proposed packing algorithm can handle objects with holes or cavities and its performance does not degrade significantly with the increase in complexity of the enclosure or the objects. The packing algorithm takes as input the triangulated geometry of the container and all the objects to be packed and outputs the list of objects that can be placed inside the enclosure. The packing algorithm also outputs the location and orientation of all the objects, the packing sequence, and the packed configuration. An improved layout algorithm that works with arbitrary container geometry is also proposed. Several heuristics to improve the performance of the packing algorithm as well as certain aspects that facilitate fast and efficient handling of CAD data are also discussed. A comprehensive benchmarking of the proposed packing algorithm on synthetic and hypothetical problems reflects its superior performance as compared to other similar approaches.
The Integration of Affective Design Into QFD
Authors: Van Bossuyt Douglas , Gibson Brenton , Wo¨rz Ulrich , Zaworski Joseph
Published: July 2009

The use of design methodologies in product development has been proven to work for functional and performance requirements. However, when it comes to more abstract requirements — like attractivity — existing, widely accepted design methodologies do not provide guidance. This paper introduces tools commonly used in psychology for determining and quantifying Sensory Requirements and then proceeds to detail a method for collecting and preparing data on sensory attractiveness in a way that it is readily incorporated into the well defined method for product development, Quality Function Deployment.
A Subdivision Scheme for Discrete Motion Generation and Swept Volume Analysis
Authors: Trujillo Carlos A. , Ge Qiaode Jeffrey
Published: July 2009

In this paper, the four-point interpolatory subdivision scheme for curve generation is adapted to the interpolation of a set of positions of a cylindrical tool represented by dual quaternions. The resulting discrete model of the tool path lends itself naturally to an algorithm for computing the characteristic curve belonging to the boundary surface of the swept volume of a cylinder at each of the discrete positions. This approach to compute the discrete model of the swept surface of a motion is numerically robust and computationally efficient since it is based only on linear combinations. The results have applications in NC simulation and verification, robot path planning, and computer graphics.
Conceptual Design of a Positively Engaged Continuously Variable Transmission
Authors: Dalling Ryan R. , Haupt B. Levi , Todd Robert H.
Published: July 2009

Previous research and publications at Brigham Young University have established the new positive engagement continuously variable transmission (PECVT) family of continuously variable transmissions (CVTs). Various embodiments of PECVTs have been identified and surveyed; resulting in the identification of the behavior termed the non-integer tooth problem. Additional research has been conducted to further explore the non-integer tooth problem and identify a feasible solution to the problem through the use of a product development method. This publication will address the conceptual design phase of the product development process for a PECVT. This will include: the identification of the operating conditions of a PECVT, i.e. further detail of the non-integer tooth problem, identification of required characteristics for a solution, design specifications, concept generation, concept evaluation, and concept selection. The conceptual design phase will result in a conceptual solution which will satisfy the identified characteristic requirement and designs specifications.
Robust Design of Flexure Based Nano Precision Compliant Mechanisms With Application to Nano Imprint Lithography
Authors: Patil Chinmaya B. , Sreenivasan S. V. , Longoria Raul G.
Published: July 2009

Flexure-based compliant mechanisms are the preferred motion guiding systems for small range, nano-precision positioning applications because of excellent characteristics like friction-free continuous motion. These mechanisms are commonly used in nano fabrication equipment and ultra precision instruments. However, machining imperfections induced geometric errors in the mechanisms are known to cause undesirable parasitic motion and significant loss of precision. A systematic design approach to minimize the sensitivity of the flexure mechanisms to geometric errors induced by machining tolerances is presented here. Central to the design approach is the screw systems based analytical model to study the spatial motion characteristics of flexure mechanisms. Using this model, the parasitic motion is classified into those errors which can be corrected by calibration (extrinsic) and those which are coupled with the mechanism motion and cannot be corrected by apriori calibration (intrinsic). Metric to quantify the intrinsic parasitic motion results naturally from the screw systems analysis, and is used to represent the precision capability of the flexure mechanism. The analytical model enables the selection of geometric parameters of flexure joints of the mechanism via an optimization scheme with the aim of minimizing the parasitic motion metric. The statistical nature of the machining tolerances is accounted for by sampling the random variables at every iteration step of the optimization, leading to a stochastic formulation. The robust design approach is illustrated using a one DOF rotational flexure mechanism that is used in nano-imprint lithography equipment. Numerical results of the optimization indicate up to 40% improvement in the precision capability of the mechanism without any change in the manufacturing tolerance limits. Further, it is shown via eigenscrew analysis of mechanism compliance that the robustness resulting from the optimal flexure joint design can be attributed to the improved compliance distribution.
An Investigation on the Students’ Perception of Dissection Effectiveness in a Redesign Context
Authors: Okudan Gu¨l E. , Mohammed Susan
Published: July 2009

Disassemble/Analyze/Assemble (DAA) activities involve the disassembly, analysis, and assembly of an artifact. Such activities are frequently made a part of the undergraduate engineering curricula in the United States (and elsewhere) as they provide useful ‘hands-on’ active learning components that can be easily integrated into various courses. DAA activities are central to product dissection and reverse engineering, terms which have been used interchangeably in the engineering design education literature and course titles. In some cases these activities are coupled with redesign activities, paving the way for a good context and providing a background for a meaningful engineering design. Despite this fact, however, based on our review of the literature it is not clear how do these DAA activities help with the redesign activity, if at all. Accordingly, in this paper we present results of our data collection that aimed at uncovering students’ perception regarding if DAA activities help with redesign (e.g., is it easier to redesign after dissection?). Overall, students had positive perceptions toward dissection, specifically with regards to its impact on redesign. We also report on the relation of student perceptions to design task, team functioning, and tolerance for ambiguity.
Use of Measurements for Information System Introductions
Authors: Malvius Diana , Bergsjo¨ Dag , Norell Margareta
Published: July 2009

Methods, or more correctly a lack of methods, for measuring information systems (IS) introductions are discussed in this paper. Industry practice when it comes to IS investment evaluation methods is reported on based on findings from nine in-depth interviews with IS/IT experts from automotive companies, IS suppliers and IS consultancy firms. It is suggested that identified and existing methods can be divided into three groups, namely: subjective estimations, economic measurements, and convenient measurements. It is concluded that no complete or reliable method for measuring the success of IS introductions are recognized within studied companies or reviewed literature. It is argued that IS introductions, being a costly investment to most companies, should be evaluated in order to obtain improved company and IS user value and to better justify the investment.
Modeling and Simulation of a Magnetorheological Mount
Authors: Nguyen The , Ciocanel Constantin , Elahinia Mohammad
Published: July 2009

Magnetorheological (MR) mounts have been developed to replace hydraulic mounts because the MR effect makes the mount controllable and more adaptive. An MR mount, except for the added damping due to magnetic field, operates similarly with a hydraulic mount. Therefore, the geometry of the flow paths (inertia tracks) and the distribution of the magnetic field across these paths affect significantly the mount behavior. In this study, different geometries for the flow paths of an MR mount, designed to operate in flow mode, are considered and their effect on the mount behavior is simulated. The effects of the different geometries considered are quantified through changes in displacement transmissibility of the mount over a 0 to 70 Hz frequency range. The results of the analysis provide useful insights about model parameter values and contribute to the successful design of the flow mode operating MR mount.
Knowledge Representation and Ontology Mapping Methods for Product Data in Engineering Applications
Authors: Zhan Pei , Jayaram Uma , Jayaram Sankar , Kim OkJoon , Zhu Lijuan
Published: July 2009

This work seeks to create a semantic approach that uses ontologies for sharing knowledge related to product data in CAD/CAE applications and for integrating the design evaluation information that these applications individually provide. Our overall approach is coined OADE, Ontology-based Adaptive Design Evaluation. This paper reports on a piece of our ongoing work in this area. The key contributions of this paper include methods for the design of knowledge representation in product design and analysis, population of product data semantics, creation of ontology mapping methods and mapping representations, and mapping of product data semantics to the target application. The mapping method finds matching concepts between different ontologies based on three basic concept relation types: composition, inheritance, and attribute. A prototype implementation is being created using technologies such as OWL (representation tool), Jena (ontology builder), and Prote´ge´ (ontology editor) to demonstrate the approach for integrating a parametric CAD system, custom virtual assembly application, and an ergonomics engineering application. An example is given in this paper to illustrate how this approach can help integration between a product design application and an assembly simulation analysis application. The significance of this work is that it will provide the capability to create, share, and exchange knowledge for solving design evaluation challenges involving multiple applications and multiple viewpoints. A design decision can thus be described using the common concepts across the diverse entities.
VR Mediated Skill Transfer
Authors: Watanuki Keiichi
Published: July 2009

This paper proposes a new virtual reality mediated skill transfer and human resource development system for manufacturing technology and skill, which are composed of the explicit and tacit knowledge transfer systems using synchronized multimedia and the knowledge internalization system using portable virtual environment. In our proposed system, the education content is displayed in the immersive virtual environment, whereby a trainee may experience work in the virtual site operation. Provided that the trainee has gained explicit and tacit knowledge of casting through the multimedia-based knowledge transfer system, the immersive virtual environment catalyzes the internalization of knowledge and also enables the trainee to gain tacit knowledge before undergoing on-the-job training at a real-time operation site.