bluuebunny/crossref_metadata_2025 huggingface dataset:
Behavior of Unconfined Swirling Flames Under Fuel-Lean Conditions Using Particle Image Velocimetry
Authors: Archer S. S. , Gupta A. K.
Published: June 2008

The effect of swirl and combustion are presented to determine the flow dynamics of a fuel-lean direct injection (LDI) configuration under unconfined non-burning and combustion conditions. Specifically, the effect of radial distribution of combustion air swirl in a burner is examined under non-burning and burning conditions using propane as the fuel. The study explores the swirl flow interaction with the use of an experimental double concentric swirl burner that simulates one swirl cup of a practical gas turbine combustor. Three-dimensional (3-D) flowfield data has been obtained immediately downstream of a double concentric swirl burner exit using PIV, to determine the flow dynamics associated with the flow under fuel-lean direct injection (LDI) conditions. Propane fuel was injected radially into the surrounding swirl flow. Flow characteristics of the resulting flowfield, both without and with combustion have been obtained for co- and counter-swirl distributions to the combustion air flow under unconfined environment. Flat vane swirlers have been used to induce swirl to the air flow. Both combustion and swirl distribution significantly influences the resulting flowfield. The 3-D data also allows one to determine the local swirl number of the resulting flow. Results show that swirl distribution in the burner and combustion has significant effect on the characteristics of the internal and external recirculation zones. The heat release from combustion enhanced the inner recirculation zone by increasing its width and length. Combustion increased the magnitude of the vorticity and provided enhanced symmetry to the flowfields. The calculated local swirl number differs under non-burning and combustion cases. They also differ from that estimated using available geometrical relationships that are derived from the swirl vane angle and swirler dimensions only. Combustion enhanced significant increase in velocity magnitudes than that for the no combustion conditions. The entrained mass flowrate is larger for the co-swirl distribution cases and this entrainment is further enhanced with combustion. The results provide the role of radial swirl distribution and combustion on the mean and turbulence characteristics of flows for two varying shear conditions between the inner and outer flow of the burner, thus providing insightful information on the flow dynamics in complex swirl flowfields in addition to providing data for model validation and model development.
Applying the Mahalanobis-Taguchi System to Vehicle Handling
Authors: Cudney Elizabeth A. , Paryani Kioumars , Ragsdell Kenneth M.
Published: June 2008

The Mahalanobis Taguchi System (MTS) is a diagnosis and forecasting method for multivariate data. Mahalanobis Distance (MD) is a measure based on correlations between the variables and different patterns that can be identified and analyzed with respect to a base or reference group. The MTS is of interest because of its reported accuracy in forecasting from small, correlated data sets. This is the type of data that is encountered with consumer vehicle ratings. MTS enables a reduction in dimensionality and the ability to develop a scale based on MD values. MTS identifies a set of useful variables from the complete data set with equivalent correlation and considerably less time and data. This paper presents the application of the MTS, its applicability in identifying a reduced set of useful variables in multidimensional systems.
Design of Oxidizer Referenced Fuel Pressure Regulator
Authors: Rousseau Tony , Terry Jonathan , Amano R. S.
Published: June 2008

This research involves the development and testing of a pressure regulator designed to maintain a constant pressure and mass flow relationship between the oxidizer and fuel source of a nitrous oxide injection system. Regulator design was accomplished through the exhaustive process of reviewing various fuel control and oxidizer referencing designs coupled with finite element analysis on the oxidizer referenced components to determine whether the selected components could handle the relatively high forces generated by the 1000psi nitrous oxide. The testing phase of the project was done in a dynamometer cell and involved numerous dynamometer tests of an engine supplied with a nitrous oxide kit both with and without the oxidizer referenced fuel pressure regulator. These tests monitored critical areas such as peak cylinder pressure, the location of the peak cylinder pressure, the air/fuel ratio, the nitrous oxide bottle pressure, and the knock intensity. The data collected in each of these areas was used to compare the performance of a regulated and non-regulated system as well as ensure the safe and reliable operation of the engine.
A Study on the Practicalities of Using Volumetric Three-Dimensional Imaging Devices in Design
Authors: Opiyo Eliab Z. , Horva´th Imre
Published: June 2008

Standard two-dimensional (2D) computer displays are traditionally used in engineering design to display the three-dimensional (3D) images generated by computer-aided design and engineering (CAD/CAE) systems. These displays serve primarily as passive visualization tools. The interaction with the displayed images on these devices is only possible through archaic 2D peripheral input devices such as keyboards and mice; via the Windows, Icons, Menus and Pointing (WIMP) style graphical user interfaces. It is widely acknowledged in the design community that such visualization and interaction methods do not match the way the designers think and work. Overall, the emerging volumetric 3D displays are seen as the obvious replacement of flat displays in future. This paper explores the possibility of stepping beyond the present 2D desktop computer monitors, and investigate the practicalities of using the emerging volumetric 3D displays, coupled with non encumbering natural interaction means such as gestures, hand motions and haptics for designing in 3D space. We first explore the need for spatial visualization and interaction in design, and outline how the volumetric 3D imaging devices could be used in design. We then review the existing volumetric 3D display configurations, and investigate how they would assist designing in 3D space. Next, we present the study we conducted to seek views of the designers on what kind of volumetric 3D display configuration would more likely match their needs. We finally highlight what would be the consequences and benefits of using volumetric 3D displays instead of the canonical flat screen displays and 2D input devices in design. It has been established that the designers who participated as subjects in the above-mentioned preliminary field study feel that dome-shaped and aerial volumetric 3D imaging devices, which allow for both visualization and interaction with virtual objects, are the imaging options that would not only better suit their visualization and interaction needs, but would also satisfy most of the usability requirements. However, apart from dealing with the remaining basic technological gaps, the challenge is also on how to combine the prevailing proven CAD/CAE technologies and the emerging interaction technologies with the emerging volumetric 3D imaging technologies. As a result of turning to volumetric 3D imaging devices, there is also the challenge of putting in place a formal methodology for designing in 3D space by using these devices.
Favored Feature Based Shape Generation: Externalization of Latent Preference
Authors: Yanagisawa Hideyoshi , Murakami Tamotsu , Fukuda Shuichi
Published: June 2008

Product styling, which is difficult to describe as a specification, has become an important factor in the current saturated market in which many products possess similar functionalities. In this paper, we propose a favored-feature-based design support method which helps the user to externalize his or her image of styling design into a shape without the use of any drawing techniques. The computer system based on this method works through interaction with the user. The user evaluates design samples generated by the system. The system estimates the favored features to which the user unconsciously pays greater attention. The user selects one of the estimated favored features to generate new design samples. The system automatically generates design samples based on the favored feature. The use of the system causes the user to notice his/her own unconscious preferences by displaying showing the favored features. Thus, the user becomes consciously aware of his/her own latent perspectives of design. Through repetition of this operation, the user gradually expands his/her perspectives and can generate a greater variety of design samples based on them. Operation of this system is easy compared with the conventional design system, in which the user must manually adjust the design parameters and which we shall call the manual design system. Therefore the non designer customer can readily express his/her image of style requirements as an actual shape. The proposed method is compared with the manual design system and its effectiveness is demonstrated by a design experiment using a 3D cylinder model consisting of superquadratic ellipse cross sections.
Motion Characteristics of a Square Wheel Car
Authors: Derby Stephen J. , Anderson Kurt , Winckler Steven , Winckler Jason
Published: June 2008

A mechanical locomotive device that uses square wheels has been developed (patent pending), and a working prototype of one configuration has been built. This invention has applications to current locomotive devices, like robots or vehicles, as well as the potential to be used in micro devices (MEMS). The prototype uses a motor to create a moving force (a weight in this case), which moves in a repeating pattern, that in turn causes the device to move in a straight line, and there is no direct connection between the ground and the motor. Consequently, the device could work using any means to produce a moving force (weight, electrostatic, electromagnetic, aerodynamic, and so on). This paper describes the gait of the square wheels and looks at a sample of the results of standard dynamic modeling and analysis to understand the strengths and limitations of this new device.
An Agent-Based Approach to Collaborative Product Design
Authors: Wang Jian Xun , Tang Ming Xi
Published: June 2008

The growth of computer science and technology has brought new opportunities for multidisciplinary designers and engineers to collaborate with each other in a concurrent and coordinated manner. The development of computational agents with unified data structures and software protocols can contribute to the establishment of a new way of working in collaborative design, which is increasingly becoming an international practice. In this paper, we first propose a computational model of collaborative product design management aiming to improve the efficiency and effectiveness of the cooperation and coordination among participating disciplines. Then, we present a new framework of collaborative design which adopts an agent-based approach and relocates designers, managers, systems, and supporting agents in a unified knowledge representation scheme for product design. An agent-based system is now being implemented and the design of a set of dinning table and chairs is chosen to demonstrate how the system can help designers in the management and coordination of the collaborative product design process.
Growth Design Modeling
Authors: Huang Kezheng
Published: June 2008

As an essential part of design, the conceptual design needs computer assistance from its initial design stage of product development. However computer-aided conceptual design is limited by the current function-to-form mapping approaches. A new growth design process model is proposed in this paper in which geometrical solutions grow gradually from scratch to their complete configurations. Two theoretical design principles, Decomposition & Reconstitution (D&R) principle and Cell Division principle, are briefly introduced to provide better understanding of Growth Design model. The concept of Conceptual Structure is used to support the transition process from conceptual design to detailed design in the growth design process. Finally, an application case is introduced to show the effects of the growth design model.
A Three-Dimensional Generalization of Reuleaux’s Method Based on Line Geometry
Authors: Baroon Jasem , Ravani Bahram
Published: June 2008

In kinematics, the problem of motion reconstruction involves generation of a motion from the specification of distinct positions of a rigid body. In its most basic form, this problem involves determination of a screw displacement that would move a rigid body from one position to the next. Much if not all of the previous work in this area has been based on point geometry. In this paper, we develop a method for motion reconstruction based on line geometry. An elegant geometric method is developed based on line geometry that can be considered as a generalization of the classical Reuleaux’s method used in 2D kinematics. The case of over determined system is also considered a linear solution is presented based on least squares method.
Distributed Real-Time Vehicle Validation
Authors: Nybacka Mikael , Larsson Tobias , Johanson Mathias , To¨rlind Peter
Published: June 2008

Due to the increasing complexity of embedded systems and software in vehicles, the automotive industry faces an increasing need for testing and verification of components and subsystems under realistic conditions. At the same time, development cycles must be shortened for vehicle manufacturers to be competitive on the global market, and an increased amount of testing and verification must thus be performed in less time. However, simply increasing the testing volume can be prohibitively costly, meaning that testing and verification processes must be made more efficient to reduce the need for more prototypes. This paper presents a concept for distributed testing and verification of vehicles in real-time, with the aim of improving testing and verification efficiency. Through a novel combination of software tools for distributed collaborative engineering, real-time simulation, visualization, and black box simulation, the realized system makes it possible for vehicle manufacturers and their subcontractors to work more concurrently and efficiently with testing and validation. An early implementation of a system prototype is described and future development plans for the system are presented. The main software components used to build up the system are ADAMS/Car RealTime, Matlab/Simulink and a Java-based real-time visualization module originally developed for the gaming industry. A main benefit of the concept is that different disciplines involved in the product development process can use the system to enhance the concurrency between them. Control systems and mechanical engineers can view ongoing tests in real-time and change designs, and efficiently re-simulate and influence ongoing tests in a distributed manner. Through advanced visualization of simulation results and measurement data, engineers can get a clearer view of how the system or product behaves, thereby improving the quality of the validation process. The concept for distributed real-time simulation and visualization described in this paper will gather more information during the early stages of product development, and speed up the product development process due to its real-time nature. The fact that engineers can stay at their home office and only follow the test when needed will enhance their efficiency.
Realtime Dome Imaging and Interaction: Towards Immersive Design Environments
Authors: Bailey Mike , Clothier Matt , Gebbie Nick
Published: June 2008

As engineering design becomes more and more complex, we predict that the field will look to immersive environments as a way to create more natural interactions with design ideas. But, helmets are bulky and awkward. A better solution for immersive design is a partial dome. Originally the exclusive domain of flight simulators, dome projection is now being brought to the masses with less expensive dome displays and because its immersiveness makes it such a unique design and display experience. A fisheye lens is needed for the projector to display across the nearly 180° of the dome. This necessarily introduces a distortion of the graphics that is being displayed through it. The trick is to then “pre-distort” the graphics in the opposite direction before sending it on to the projector. This paper describes the use of the OpenGL Shading Language (GLSL) to perform this non-linear dome distortion transformation in the GPU. This makes the development of dome-ready interactive graphics code barely different from developing monitor-only graphics code, and with little runtime performance penalty. The shader code is given along with real examples from our work with San Diego’s Reuben H. Fleet Science Center.
A Study of the Duality Between Epicyclic Gear Trains and Beam Systems
Authors: Pennock Gordon P. , Alwerdt Jeremiah J.
Published: June 2008

This paper provides geometric insight into the duality between the kinematics of epicyclic gear trains and the statics of beam systems. The two devices have inherent geometrical relationships that allow the angular velocities of the gears in a gear train to be investigated from a knowledge of the forces acting on the dual beam system, and vice-versa. The primary contribution of the paper is the application of this duality to obtain the dual beam system for a given compound epicyclic gear train. The paper develops a systematic procedure to transform between the first-order kinematics of a gear train and the statics of the dual beam system. This provides a simple and intuitive approach to study the speed ratios of an epicyclic gear train and the force ratios of the dual beam system. The speed ratios are expressed in terms of kinematic coefficients, which are a function of the position of the input gear and provide insight into the gear train geometry. Several numerical examples of simple and compound epicyclic gear trains are presented to demonstrate the simplicity of the proposed approach. The analytical equations that are developed in the paper can be incorporated, in a straightforward manner, into a spreadsheet that is oriented towards an epicyclic gear train satisfying specific design requirements.
Enabling Local Risk Assessment to Support Global Collaboration in a Distributed Environment
Authors: Qiu Yuming , Ge Ping , Yim Solomon C.
Published: June 2008

Risk is a crucial criterion for decision making among multiple stakeholders negotiating for an agreement in a distributed environment. The challenge here is that risk may have different meanings and implications to different stakeholders, and this creates considerable barriers to effective negotiation and coordination in collaborative design. Our goal is to 1) capture the heterogeneous risk information at intra- and inter- stakeholder levels, 2) represent them using a uniform structure based on a function-failure relationship, and 3) enable the negotiation of the risk information among the multiple stakeholders through this uniform structure. Though a significant number of existing methods for risk analysis and management have been developed, these methods mainly focus on the local domain of a certain single stakeholder, and few have considered the possible influence and variations related to global aspects that is important for negotiation among multiple, distributed stakeholders. This work develops intra-level risk property tables to capture and represent the various risk evaluations from individual members in a single stakeholder; and then inter-level risk property tables are formed based on the synthesis of the various intra-level risk properties into a group representation for the single stakeholder, which is directly used in global negotiation and coordination with other stakeholders. An adjustable approach is used in our work to enable the adjustability of the intra- and inter- level risk evaluations via negotiation. An example problem from a NSF/NEES-sponsored research collaborative network is used to demonstrate the use of this method. The preliminary results show that this method has potential in enabling local risk assessment to support global negotiation and coordination in a distributed, collaborative environment.
Elastic-Plastic Finite Element Stress Analysis of a Carburized Shaft With Spatial Gradient in Mechanical Properties
Authors: Tibbits Patrick A.
Published: June 2008

Low core hardness in a carburized bicycle pedal shaft allows yielding in the core region when the shaft carries a bending load. Quantitatively evaluating the effect of core hardness level requires simulation of the gradient in material properties from the high-hardness thin outer case to the low-hardness core. This study develops a scheme for generating a high-resolution finite element mesh near the outside diameter of the shaft, coupled with a method for specifying elastic-plastic stress-strain curves which vary with depth below the carburized surface. The method enables examination of the stress localization and intensification in the case when yielding occurs in the core. The results show the insufficiency of the linear elastic assumption, and explain failures of shafts with anomalously low core hardness.
Design Competence Development in an Academic Virtual Enterprise
Authors: Horva´th Imre
Published: June 2008

Development of competence has been one of the major issues and goals of modern academic design and engineering education. Nevertheless, our literature study revealed that we are still far from a common interpretation of design competence. There are different views on it which we called reductionist and holistic. In the reductionist view, design competence is considered to be not else than a set of low level competencies such as drawing skills, spatial vision, specialized knowledge, intuitiveness and creativity, verbal communication, and technical writing, which have been typically addressed disjointedly. In the holistic view, design competence is a synergetic construct of some generic capacities. We followed this latter view in our work. We studied the implementation opportunities and manifestation of holistic design competence at the development and conduct of our recent European Global Product Realization course. Based on our past experiences and the information from the literature, we assumed that holistic design competence is a construct of five generic capacities: capabilities, attitude, knowledge, skills, and experiences, and can be efficiently developed by concurrently focusing on each of these, respectively. The professional content and didactic approach of the course were designed accordingly. An academic virtual enterprise was formed with the involvement of an industrial company and universities of five countries. The course included two instructional streams, which have been called professional navigation and industrial project. This paper presents our interpretation of holistic design competence, the didactic aspects of developing the underpinning generic capacities, and their manifestation in the European Global Product Realization course. A qualitative research has been completed with the involvement of 46 students to make out how our approach contributed to the development of the elementary design competencies. The conclusion has been that our approach equally well supports the development of both the holistic design competence and the elementary design competencies that are needed by product designers to be able to successfully operate in geographically dispersed virtual enterprises. The students’ opinion has been that the course was challenging but rewarding from the point of view of their future carrier as product designers.
Burmester and Allievi: A Theory and Its Application for Mechanism Design at the End of 19th Century
Authors: Ceccarelli Marco , Koetsier Teun
Published: June 2008

The second half of 19-th century can be considered the Golden Age of TMM for the achieved theoretical and practical results that stimulated and obtained enhancements of machinery for Industrial Revolution. Burmester and Allievi can be considered as significant examples of that time for their personality and professional experiences as well as for their works on Kinematics of Mechanisms. In this paper a survey is presented on their curriculum and scientific main works on Mechanism Design with the aim also to stress similarities and differences in the life of kinematicians and in developments of Mechanism Design at the end of 19-th century.
An Experimental Comparative Study on Non-Circular Gears and CAM Transmissions for a Blood Pumping System
Authors: Ottaviano Erika , Lanni Chiara , Tavolieri Cristina , Mundo Domenico , Danieli Guido , Fanghella Pietro , Ceccarelli Marco
Published: June 2008

In this paper, we have reported results of experimental activity for a characterization of mechanical transmissions with gears or cams. The study has been focused on specific transmission characteristics that are related to a mechanical blood pumping design. In particular, experimental tests have been analyzed to understand benefits and drawbacks for using non-circular gears and polynomial cams in pure mechanical transmissions with limited motion regulation but with specific prescribed motion law.
Counterweight Balancing for Reducing Machine Frame Vibration: A Convex Optimization Framework
Authors: Verschuure Myriam , Demeulenaere Bram , Swevers Jan , De Schutter Joris
Published: June 2008

This paper focusses on reducing, through counterweight addition, the vibration of an elastically mounted, rigid machine frame that supports a linkage. In order to determine the counterweights that yield a maximal reduction in frame vibration, a non-linear optimization problem is formulated with the frame kinetic energy as objective function and such that a convex optimization problem is obtained. Convex optimization problems are nonlinear optimization problems that have a unique (global) optimum, which can be found with great efficiency. The proposed methodology is successfully applied to improve the results of the benchmark four-bar problem, first considered by Kochev and Gurdev. For this example, the balancing is shown to be very robust for drive speed variations and to benefit only marginally from using a coupler counterweight.
Computational Methods Using Excel/VBA for Engineering Applications
Authors: Lilley David G.
Published: June 2008

The focus is that Excel/VBA provides a useful platform for engineering calculations in energy engineering. It includes computational methods in the simulation and solution of engineering problems that may or may not have analytical exact mathematical solutions. Emphasis is on the methods and applications, using Excel as the interface for data input and output, tables and figures, and Visual Basic for Applications VBA as the programming language for computations. Fundamental topics of: • Linear and Nonlinear Sets of Equations; • Interpolating Polynomials; • Differentiation and Integration; • Solution of ODEs – Initial and Boundary Value Problems; • Solution of PDEs – Elliptic, Parabolic and Hyperbolic; • Graphics, including Plotting and Data Presentation, and Curve Fitting. Connections are made between each topic and a variety of engineering problems and applications. In this approach, it is emphasized how to develop and apply numerical techniques to solve engineering problems.
Topology and Classical Shape Optimization of a Lower Control Arm: A Case Study
Authors: Krishna Murali M. R. , Stange Aaron
Published: June 2008

This paper addresses the design of a lower control arm of a sport utility vehicle. Four worst load cases were identified and for each of them the forces and moments at each of the three ends of the arm were obtained as input. There was also some space constraint within which the arm had to be designed. A finite-element based methodology is presented here to design a lower control arm. First Topology optimization is applied to get an overall approximate shape within the design space. This process is similar to finding out a load path for the structure to withstand the loads. This shape is then sized to withstand all the loads using classical shape optimization techniques. Shape vectors, which are the most important inputs for shape optimization, are generated for the different regions of the control arm. This case study illustrates the complete process of topology and shape optimizations to get a final design of the lower control arm.
Parametric Solid Modeling
Authors: Ilies¸ Horea T.
Published: June 2008

Parametric modeling systems are fundamentally changing the design process practiced in the industry today. Practically all commercial CAD systems combine established solid modeling techniques with constraint solving and heuristic algorithms to create, edit and manipulate solid models, while enforcing the requirement that every such solid model must maintain the validity of the prescribed geometric constraints. However, a number of fundamental (open) problems limit the functionality and performance of these parametric modeling systems. For example, the allowable parametric changes are history dependent; the number of parameters describing even relatively simple parts can quickly become prohibitively large, and commercial constraint solvers are limited today to 2-dimensional geometric constraints. Consequently, current parametric modeling systems do not support many practical design situations due to the associated theoretical and computational difficulties, as well as to the considerable organizational obstacles generated by the need to handle large parametric models. This paper investigates the current practices and limitations of parametric solid modeling systems, and explores some alternative approaches that could complement the identified limitations.
Model-Based Decomposition Using Non-Binary Dependency Analysis and Heuristic Partitioning Analysis
Authors: Li Simon , Chen Li
Published: June 2008

The two-phase method for model-based decomposition (Chen et al. 2005a) has two major functional components: dependency analysis and partitioning analysis. The functions of these two components are enhanced and generalized in this paper in order to improve the method’s capability. On the one hand, the non-binary dependency analysis is developed such that the two-phase method can handle both binary and non-binary dependency information of the model. The essence of this development is to properly select a resemblance coefficient for the quantification of couplings among the model’s elements. On the other hand, as the past version of partitioning analysis takes the enumerative approach to search decomposition solutions, the heuristic partitioning analysis is developed as an alterative to search a reasonably good solution in a shorter time. The working principle of the heuristic approach is to analyze the coupling structure of the model such that the weak coupling links among the model’s elements can be identified for model partitioning. At the end, a relief valve system is applied to illustrate and justify the newly developed method components.
Three-Cable Haptic Interface
Authors: Williams Robert L. , Chadaram Venkat , Giacometti Federica
Published: June 2008

We present our three-cable haptic interface (TCHI) concept, plus modeling and simulation, hardware implementation, and initial experimental results. This device is based on a previous system developed by Italian researchers. Cable devices are limited since they cannot push on the user, but only apply positive tension. In addition, this TCHI is further limited since it has no actuation redundancy and forces can only be applied within the tetrahedron formed by the fingertip point and base cable attachment points. Despite these limitations, which are explored herein, we believe the simplicity of this haptic interface can make it a serious competitor of existing commercial devices in terms of workspace, force application, cost, safety, and stiffness.
Qualitative and Quantitative Sequential Sampling
Authors: Rai Rahul , Campbell Matthew I.
Published: June 2008

This paper introduces a method for sequentially determining experiments in a “design of experiments” where optimization and user knowledge are used to guide the efficient choice of sample points. Typical approaches to the design of experiments involves determining the sample points all at once prior to any experimentation, or sequentially based on the results of previous sample points. This method combines information from multiple fidelity sources including actual physical experiment, computer simulation models of the product, first principals involved in design and designer’s qualitative intuitions about the design. Both quantitative and qualitative information from different sources are merged together to arrive at new sampling strategy. This is accomplished by introducing the concept of confidence, C, which is represented as a field that is a function of the decision variables, x, and the performance parameter, f. The advantages of the approach are demonstrated using different example cases.
Design and Verification of an Adaptive Control Algorithm for a Redundantly Actuated Omnidirectional Mobile Platform
Authors: Lee Young-Chul , Lee Danny V. , Chung Jae H. , Velinsky Steven A.
Published: June 2008

This paper discusses the design and control of a new ball-wheel drive mechanism for a robust omnidirectional wheeled mobile platform. This platform, integrated with a manipulator, is designed for use in highway maintenance and construction, which is a generally unstructured and congested environment. The proposed ball wheel mechanism can move in all directions on the plane, instantaneously and isotropically. For accurate motion with parametric uncertainty in the dynamic model, an adaptive controller is applied to the trajectory tracking control of the single ball wheel platform. The redundant drive system of the ball wheel mechanism changes its configuration according to the heading direction by changing the contact pressure between the drive wheel and the sphere. A weighted torque optimization method is used for the resolution of redundancy and for smooth reconfiguration. The experimental results demonstrate the effectiveness of the proposed method.
Virtual Part Arrangement in Assemblies for Automatic Tolerance Chart Based Stackup Analysis
Authors: Shen Zhengshu , Shah Jami J. , Davidson Joseph K.
Published: June 2008

Manual construction of design tolerance charts is a popular technique for analyzing tolerance accumulation in parts and assemblies, even though it is limited to one-dimensional worst-case analysis. Since charting rules are GD&T (geometric dimensioning & tolerancing) specification dependent, and the user has to remember all the different rules to construct a valid tolerance chart, manual charting technique is time-consuming and error-prone. The computer can be used for automated tolerance charting, which can relieve the user from the tedious and error-prone procedure while obtain the valid results faster. The automation of tolerance charting, based on the ASU GD&T mathematical model, involves (1) automation of stackup loop detection, (2) formulation of the charting rules for different geometric tolerances and determination of the closed form function for statistical analysis, (3) automatic part arrangement for an assembly level chart analysis, (4) development of the algorithms for chart analysis and automatic application of the charting rules. Since the authors’ previous DETC/CIE’03 paper already discussed tasks 1~2 and part of task 4, this paper will focus upon task 3, i.e. virtual part arrangement in assemblies for tolerance charts, and update the analysis algorithm (related to task 4). These two papers together will provide a complete coverage of automated tolerance charting technique popularly used in industry. The implementation will be briefly discussed as well, and case studies will be provided to demonstrate the approach to virtual part arrangement.
Aerodynamic Shape Optimization and Knowledge Mining of Centrifugal Fans Using Simulated Annealing Coupled With a Neural Network
Authors: Sugimura Kazuyuki
Published: June 2008

An aerodynamic shape optimization method suitable for “inexpensive” centrifugal impellers and diffusers has been developed. The shapes are parameterized using non-uniform rational B-spline curves with special attention being paid to the blade’s edge profiles. A hybrid algorithm combining simulated annealing and a neural network is employed for collaborative optimization. The simulated annealing and neural network take turns in controlling the optimization processes, not only for maximizing the efficiency of global exploration, but also for minimizing the risks of automation failures or of reaching an incorrect optimum. A statistical analysis was also conducted using the neural network to extract design knowledge. By applying the proposed method to a centrifugal impeller and diffuser design problem, we obtained innovative shapes for the leading edge of the impeller and the trailing edge of the diffuser. Important design parameters related to the new shapes were identified through the design space analysis.
Modeling Compliant Parallel Robots
Authors: Raatz Annika , Trauden Frank , Hesselbach Ju¨rgen
Published: June 2008

Since long time flexure hinges have been used in high precision devices instead of conventional bearings, e.g. ball or sliding bearings. Due to the natural lack of backlash, friction and slip-stick effects in flexure hinges, the accuracy of positioning or measurement devices can be highly increased. Recent applications for flexure hinges are seen in parallel robots. The integration of flexure hinges in parallel structures is quite simple because all joints, except for the drives, are passive. Since flexure hinges gain their mobility from an elastic and plastic deformation of matter, their kinematic behavior differs from the kinematics of ideal rotational joints. This leads to deviations of the compliant mechanism and its rigid body model. In this paper a kinematic model is proposed which allows for a compensation of the introduced hinge errors. Furthermore the dynamic model of a compliant parallel robot is derived and verified by means of simulation studies. This dynamic model can be used e.g. for model-based robot control algorithms or for the dimensioning of drives for compliant mechanisms.
Moving Product Information Along the Value Chain: Overcoming Challenges of Distributed Organizational Structure and a Heterogeneous Information Environment
Authors: Karandikar Harshavardhan , Schilli Bruno , Schellhammer Wolfgang , Karlsen Roar
Published: June 2008

Considerable attention has been paid, both in research and practice, to the creation and management of digital product information comprising parametric product data, documents and CAD files. There has been less focus on cost-effective delivery of this information to different user groups and for myriad uses. This poses a major challenge in companies with globally distributed production units as well as customers. Attention also needs to be paid on how the use of this digital information can be made easy through uniform structuring and a common look and feel. We highlight, in this paper, the complex issues and challenges in electronically delivering and managing digital product information for industrial customers. We then present a cost-effective and flexible IT solution that aims for a high level of automation in the delivery process.
A Parallelogram-Based Parallel Manipulator For Scho¨nflies Motion
Authors: Salgado Oscar , Altuzarra Oscar , Amezua Enrique , Herna´ndez Alfonso
Published: June 2008

A parallelogram-based four degrees-of-freedom parallel manipulator is presented in this paper. The manipulator can generate the so-called Scho¨nflies motion, that allows the end-effector to translate in all directions and rotate around an axis parallel to a fixed direction. The Theory of Group of Displacements is applied in the synthesis of this manipulator, which employs parallelograms in every limb. The planar parallelogram kinematic chain provides a high rotational capability and a improved stiffness to the manipulator. The paper shows the kinematic analysis of the manipulator, including the closed-form resolution of the forward and inverse position problems, the velocity and the singularity analysis. Finally, a prototype of the manipulator and some technical applications in which the manipulator can be used are presented.
Agustin Betancourt: An Early Modern Scientist and Engineer in TMM
Authors: Erogova Olga , Ceccarelli Marco , Cuadrado Iglesias Juan Ignacio , Lopez-Cajun Carlos S. , Pavlov Vladimir E.
Published: June 2008

In this paper, we have presented the personality and activity of Agustin Betancourt who can be considered among the first modern mechanical (industrial) engineers with a strong formation and expertise in TMM. Indeed his activity can be considered as a significant example of personality in the early modern developments of TMM but also how TMM formation has been useful for engineers and managers in the overcoming Industrial Revolution. In particular, Betancourt can be seen as an emblematic example of the international vision of TMM and its application, since he has been a successful scientist, engineer, and manager in Spain, France, and then Russia.
Development of a Blanket Manipulation Tool for Satellite Servicing
Authors: Laliberte´ Thierry , Gosselin Cle´ment M.
Published: June 2008

It is expected that unmanned on-orbit satellite servicing will soon become state-of-the-art operations. Such tasks will require new robotic tools. In this context, this paper presents the development of a grasping tool for the handling of satellitic thermal blankets. The mechanical design of the tool is first addressed. Mainly, actuated jaws adapted to grasp and lift a thermal blanket attached with velcros are developed. Also, passive compliance is included in order to cope with a position controlled robotic arm and a rigid surface. Then, sensing issues are discussed and included in the design. These features are integrated in a prototype mainly built of plastic by rapid prototyping. Finally, experimental results show that the tool developed in this work is capable of effectively removing thermal blankets.
Visibility for Determining the Rotational Axis CNC Rapid Prototyping and Rapid Manufacturing
Authors: McBrearty Kevin , Wysk Richard A. , Joshi Sanjay
Published: June 2008

This paper outlines the requirements for employing visibility for CNC Rapid Prototyping (RP) and Rapid Manufacturing (RM), e.g., necessary conditions for CNC RP. Visibility, as used here, is with respect to line-of-sight access for the tool to the workpiece for machining access. This method forms the basis for the selection of an axis of rotation for which the workpiece would be completely visible and a step in the automation sequence for this process. A review of prior visibility work in the area of machining is included and specifically those related to CNC RP. Additionally, there is a discussion of a new software implementation of visibility and its methodology for CNC RP. The goal of this implementation is to develop a procedure that will reduce the set of all potential workpiece rotational axes to a subset that will provide full visibility. Results are presented for the software tool along with potential improvements for the future.
ACL Message-Oriented Agent Communication and Migration
Authors: Chen Bo , Linz David D. , Cheng Harry H.
Published: June 2008

This article presents an approach for inter-agent communication and inter-platform agent migration based on IEEE FIPA (Foundation for Intelligent Physical Agents) Agent Communication Language (ACL) messages. The promising features of IEEE FIPA standards that support open, flexible, and interoperable agent communication and migration are discussed in the paper. Messages for agent communication and migration, platform architecture that deliver and manage these messages, and the main procedure of processing a mobile agent message are also introduced. An application example, in which a mobile agent visits multiple hosts and travels via mobile agent messages, simulates a mobile agent for remote data processing. This example shows the feasibility, simplicity, and openness of the presented approach for mobile agent migration. Using FIPA ACL messages for agent migration in FIPA compliant agent systems simplifies agent platform, reduces development effort, and easily achieves inter-platform migration through well-designed communication mechanisms provided in the agent platform.
A Characterization of Cam Transmissions Through an Identification of Lumped Parameters
Authors: Carbone Giuseppe , Lanni Chiara , Ceccarelli Marco , Incerti Giovanni , Tiboni Monica
Published: June 2008

In this paper, a numerical-experimental procedure is proposed for an identification of parameters in cam transmissions. Models with lumped parameters are defined specifically for cam transmissions. Experimental tests are carried out on main components of a cam transmission in order to estimate the values of mass, damping and stiffness lumped parameters through a low-cost easy-operation procedure. Experimental tests are also carried out in order to characterize the dynamic behaviour of a whole cam transmission. A comparison of numerical and experimental results is used in order to calibrate the values of lumped parameters. Experimental tests have been carried out by means of suitable test-beds for cams that have been built specifically at University of Brescia and at LARM in Cassino as alternative testing solutions.
Ultimate and Practical Limits for Counterweight Balancing of Six-Bar Linkages
Authors: Demeulenaere Bram , Swevers Jan , De Schutter Joris
Published: June 2008

The designer’s main challenge when counterweight balancing a linkage is to determine the counterweights that realize an optimal trade-off between the dynamic forces of interest. This problem is often formulated as an optimization problem that is generally nonlinear and therefore suffers from local optima. It has been shown earlier, however, that, through a proper parametrization of the counterweights, a convex program can be obtained. Convex programs are nonlinear optimization problems of which the global optimum is guaranteed to be found with great efficiency. The present paper extends this previous work in two respects: (i) the methodology is generalized from four-bar to planar N-bar (rigid) linkages and (ii) it is shown that requiring the counterweights to be realizable in practice can be cast as a convex constraint. Numerical results for a Watt six-bar linkage suggest much more balancing potential for six-bar linkages than for four-bar linkages.
Stereolithography Mock-Up With Internal Camera for Automatic Usability Data Acquisition and Functional Simulation
Authors: Murakami Tamotsu , Nakano Michiki
Published: June 2008

In this paper, we propose a new type of mock-up consisting of a transparent solid object, fabricated by stereolithography, with a small video camera embedded inside. By processing the video image of the object surface taken from the inside in real time, operation data of the mock-up (e.g., when interfaces such as buttons and dials are operated by the users) and usage (e.g., which hand and fingers are used to operate the buttons and dials of the mock-up) data can be obtained. Consequently, a simple stereolithography model without sensors or circuits can be a functional mock-up. By analyzing these automatically obtained usage data, operation data and the result of functional simulation, some usability data will be obtained or extracted. Designers can use such data to improve the usability of the product that the mock-up imitates. The feasibility and validity of the concept is confirmed and reported on the basis of three experiments: a basic experiment using a simple mock-up consisting of a button and a dial, and two detailed experiments on usability data acquisition and the simulation of a Japanese-character-input interface using stereolithography mock-ups with a small fish-eye video camera inside.