bluuebunny/crossref_metadata_2025 huggingface dataset:
On Sequential Sampling for Global Metamodeling in Engineering Design
Authors: Jin Ruichen , Chen Wei , Sudjianto Agus
Published: June 2008

Approximation models (also known as metamodels) have been widely used in engineering design to facilitate analysis and optimization of complex systems that involve computationally expensive simulation programs. The accuracy of metamodels is directly related to the sampling strategies used. Our goal in this paper is to investigate the general applicability of sequential sampling for creating global metamodels. Various sequential sampling approaches are reviewed and new approaches are proposed. The performances of these approaches are investigated against that of the one-stage approach using a set of test problems with a variety of features. The potential usages of sequential sampling strategies are also discussed.
Modeling of Slope Discontinuities in Flexible Body Dynamics Using the Finite Element Method
Authors: Shabana Ahmed A. , Mikkola Aki M.
Published: June 2008

A large rigid body rotation of a finite element can be described by changing the definition of the axes of the element coordinate system or by keeping the axes unchanged and change the slopes or the position vector gradients. In the first method, the definition of the local element parameters (spatial coordinates) changes with respect to a body or a global coordinate system. The use of this method will always lead to a nonlinear mass matrix and non-zero centrifugal and Coriolis forces. The second method, in which the axes of the element coordinate system do not rotate with respect to the body or the global coordinate system, leads to a constant mass matrix and zero centrifugal and Coriolis forces when the absolute nodal coordinate formulation is used. This important property remains in effect even in the case of flexible bodies with slope discontinuities. The concept employed to accomplish this goal resembles the concept of the intermediate element coordinate system previously adopted in the finite element floating frame of reference formulation. It is shown in this paper that the absolute nodal coordinate formulation that leads to exact representation of the rigid body dynamics can be effectively used in the analysis of complex structures with slope discontinuities.
Redesign of a Spatial Gear Pair Using Configuration Spaces
Authors: Sacks Elisha , Joskowicz Leo , Schultheiss Ralf , Hinze Uwe
Published: June 2008

This paper presents an industrial case study in which a spatial higher pair is redesigned using our configuration space method of kinematic analysis. The task is to remove occasional blocking in an asynchronous reverse gear pair from a car transmission. A systematic kinematic analysis is required because the blocking configurations are unknown and because very few initial configurations cause blocking. We use our configuration space method of kinematic analysis to solve the problem. We determine why the gears block by constructing a series of two-dimensional configuration spaces that model the engagement kinematics. Blocking occurs when two consecutive pairs of teeth make contact during engagement. The gear angles at the contact determine whether or not the gears will block. Our analysis determines that blocking occurs in 4% of the angle space. Fine tuning the gear parameters reduces the range to 0.5%, but cannot eliminate the blocking. Removing every second gear tooth eliminates the blocking. The analysis results are consistent with the experimental data. The case study demonstrates that the configuration space method helps solve industrial problems that are outside the scope of prior work.
A Sensitivity-Based Pattern Search Algorithm for 3D Component Layout
Authors: Aladahalli Chandankumar , Cagan Jonathan , Shimada Kenji
Published: June 2008

This paper introduces the Sensitivity-based Pattern Search (SPS) algorithm for 3D component layout. Although based on the pattern search algorithm, SPS differs in that at any given step size the algorithm does not necessarily perturb the search space along all possible search dimensions. Instead all possible perturbations, or moves are ranked in decreasing order of their effect on the objective function and are applied in that order. The philosophy behind this algorithm is that moves that affect the objective function more must be applied before the moves that affect the objective function less. We call this effect on the objective function the sensitivity of the objective function to a particular move and present a simple method to quantify it. This algorithm performs better than the previous Extended Pattern Search algorithm with decrease in run time of up to 28%.
A Non-Deterministic Approach to Concept Selection Using S-Pareto Frontiers
Authors: Mattson Christopher A. , Messac Achille
Published: June 2008

The most significant design decisions are typically made during the conceptual phase of the engineering design process, when critical design features are proposed, evaluated and selected. In this paper, we explore the critical task of concept selection and propose a non-deterministic, optimization-based approach for selecting the most promising concept. The method presented in this paper builds upon the recently-proposed s-Pareto based concept selection approach. Within the framework of the s-Pareto approach, so-called s-Pareto frontiers are obtained by using the definition of Pareto optimality to identify Pareto optimal solutions that pertain to a set of distinct concepts. These s-Pareto frontiers are used to assess the tradeoffs between various proposed concepts during conceptual design. The s-Pareto approach is a marked departure from traditional concept selection methods and from the traditional use of Pareto frontiers. In this work the s-Pareto approach is extended to include uncertainties caused by stochastic design parameters as well as low model fidelity. More specifically, the reliability of design decisions is accounted for in the decision-making process. Two approaches are presented for performing non-deterministic concept selection. Two examples are given that support the approach.
Dynamic Project Navigation: Modelling, Improving, and Review of Engineering Processes
Authors: Freisleben Do¨rte , Vajna Sa´ndor
Published: June 2008

Engineering may be described as the main information and innovation source of a company. For an effective Engineering it is necessary to know well, to monitor, and to control all its processes and activities. Therefore a company needs a dynamic project and process navigation support for every user, which allows to model, to run, to react dynamically, and to evaluate activities in order to process these within given requirement, time, and cost frames. In this contribution, a system for dynamic project navigation in Engineering is presented with aspects of modelling, improvement and evaluation of processes.
A Tool Management System for Probabilistic Design Problems
Authors: Kaymaz Irfan , McMahon Chris
Published: June 2008

This paper presents a probabilistic design system (ADAPRES_NET) in which structural reliability problems are addressed by applying structural reliability methods along with a response surface method in a distributed computing environment. In this study, first the value of using distributed network computing for structural reliability analyses is explained. Secondly, a basic structure of distributed networking is given in which the fundamental concepts of network programming for structural reliability analysis are explained. Finally, the use of ADAPRES_NET is demonstrated for a case study involving the concurrent application of structural reliability analyses.
Geometric Tailoring: A Design for Manufacturing Method for Rapid Prototyping and Rapid Tooling
Authors: Sambu Shiva , Chen Yong , Rosen David W.
Published: June 2008

The goal of fabricating functional prototypes quickly is hindered by a mismatch of material properties between production materials and those used in rapid prototyping (RP) machines, such as stereolithography. Even when rapid tooling (RT) technologies are utilized for injection molded parts, differences in mold materials cause differences in molded part properties. To compensate for these material and process differences, a design for manufacturing (DFM) method is introduced, called geometric tailoring. The idea is to modify dimensions of prototype parts to match key characteristics of production parts, such as stress and deflection behaviors. For RP parts, the geometric tailoring DFM method integrates two sub-problems, one for achieving functional requirements by matching part behaviors, and one for RP process planning to incorporate manufacturing capabilities and limitations. For parts fabricated by RT, an additional sub-problem is integrated, namely injection molding process planning. Problem decomposition is critical due to the coupled nature of the sub-problems. A problem decomposition and solution procedure is presented. The geometric tailoring method is shown to enable the matching of prototype to production part behaviors, while improving manufacturability.
Design for Disassembly and the Value of Robotic Semi-Destructive Disassembly
Authors: Reap John , Bras Bert
Published: June 2008

This article explores robotic semi-destructive disassembly’s relationship with design for disassembly, and the article investigates its value as a disassembly approach for remanufacture and / or recycling. Specifically, the compatibility of design for disassembly guidelines with semi-destructive disassembly is explored. Regulatory pressures, recovering the value of products’ materials and the long-range environmental importance of cycling material flows motivate the exploration. The article compares general design for disassembly guidelines drawn from the literature with experimental results from the semi-destructive disassembly of a simple consumer product. Additionally, the value of semi-destructive disassembly is investigated. The prevailing view of semi-destructive disassembly’s value is discussed, and the realities of an experimental semi-destructive disassembly study are contrasted with these beliefs.
Life Cost-Based FMEA Incorporating Data Uncertainty
Authors: Rhee Seung J. , Ishii Kosuke
Published: June 2008

Failure Modes and Effects Analysis (FMEA) is a design tool that mitigates risks during the design phase before they occur. Although many industries use the current FMEA technique, it has many limitations and problems. Risk is measured in terms of Risk Priority Number (RPN) that is a product of occurrence, severity, and detection difficulty. Measuring severity and detection difficulty is very subjective and with no universal scale. RPN is also a product of ordinal variables, which is not meaningful as a proper measure. This paper addresses these shortcomings and introduces a new methodology, Life Cost-Based FMEA, which measures risk in terms of cost. The ambiguity of detection difficulty and severity is resolved by measuring these in terms of time loss. Life Cost-Based FMEA is useful for comparing and selecting design alternatives that can reduce the overall life cycle cost of a particular system. Next, a Monte Carlo simulation is applied to the Cost-Based FMEA to account for the uncertainties in: detection time, fixing time, occurrence, delay time, down time, and model complex scenarios. This paper compares and contrasts these three different FMEAs: RPN, Life Cost-based point estimation, and Life Cost-Based using Monte Carlo simulation for data uncertainty.
Feature-Based Computer Aided Manufacturing Planning for Mass Customization of Non-Rotational Parts
Authors: Yao S. , Han X. , Rong Y. , Huang S. H. , Yen D. W. , Zhang G.
Published: June 2008

This paper introduces a comprehensive system of production planning for mass customization. The combined features are defined based on the concept of part families. The process parameters are associated with the feature parameters so that a rapid production planning can be achieved for product design changes. Setup planning is carried out based on both the best practice knowledge in industry and the analysis based generation of setups. Manufacturing resource, fixture design, and tolerance issues are considered in the system. The cycle time estimation and standard documentation are included in the system.
Towards Modeling the Evolution of Product Families
Authors: Wang Fujun , Fenves Steven J. , Sudarsan Rachuri , Sriram Ram D.
Published: June 2008

A strategy successfully used by manufacturing companies is to develop product families so as to offer a variety of products with reduced development costs. This paper introduces our initial research on the representation of the evolution of product families and of the rationale of the changes involved. The information model representing product families is an extension of the NIST Core Product Model and consists of three submodels: Product Family, Family Evolution, and Evolution Rationale. In addition, a Unified Modeling Language (UML)-based representation and a prototype implementation of the conceptual model are introduced.
Fine Grained System Integration With Web Services
Authors: Hahn Axel
Published: June 2008

In this paper a loose system integration approach is introduced that supports the combination of distributed engineering models to a joint product representation. The integration concept connects the model to a loosely coupled Semantic Network. Web Service tool interfaces support the simple access and management of this information network. Knowledge becomes a major resource in collaborative design and product development. Metadata on engineering models at file level has difficulties to describe the interrelation of model entities between the files. With this fine grained integration approach the relations between model entities across engineering tools can be maintained and utilized as a product knowledge representation.
Manufacturing Information Management and Integrated Capacity Planning in a High Mix Electronics Manufacturing Environment
Authors: Su Joseph C. , Marrey Suresh , Damania Jignesh , Shaw Kevin
Published: June 2008

The high-end electronics manufacturing industry is challenged by the nature of medium/low volume and rich mix as it involves the management of various products and an extensive number of production recipes in a mixed productionflow. In addition, facing dynamic demands and the large amount of system transactions required to successfully manage the entire process further intensifies the complexity of the highmix supply chain. The key to enhance supply-chain operations of this complex process is the efficient use of information systems to (1) ensure the transparency of demand and (2) supply capacity data to all companies within a manufacturing supply chain. This will place companies in a position to anticipate demand fluctuations and respond accordingly. In the previous study [3], authors have introduced the development of the integrated capacity planning model in a high-mix electronics manufacturing environment. This ongoing study further enhances the model with the incorporation of sectionized yield information to improve the planning accuracy and the manufacturing execution information to validate the accuracy. In the previous study [3], an integrated capacity planning tool, composed of Tool Capacity Planning System (TCP) and Integrated Planning System (IPS), was introduced. TCP, an Advanced Planning and Scheduling (APS) tool, consists of a simulation system and a database that can be used to plan for the necessary equipment capacity with demand data. IPS is used for workload and staffing requirement planning. In this research, we further introduce the addition of the Manufacturing Data Warehouse (MDW), which hosts the operational data obtained from the manufacturing execution system. This addition enables the achievement of the abovementioned objectives, incorporation of sectioned yield information to improve the planning accuracy and the manufacturing execution information to validate the accuracy. The organization of this paper is as follow. The need and concept of integrated capacity planning are first described, followed by a review of some related works. The methodology section introduces the concept of unit hour and sectionized yield, as well as planning validation. Followed are several aspects of system development, including design guideline, requirement analysis, system architecture and system modeling. Some illustrated examples of said development activities are presented as well.
Hierarchical Role-Based Viewing for Secure Collaborative CAD
Authors: Cera Christopher D. , Braude Ilya , Comer Immanuel , Kim Taeseong , Han JungHyun , Regli William C.
Published: June 2008

This paper provides a framework for information assurance within collaborative design based on a technique we call rolebased viewing. Role-based viewing enables role-based access control through geometric partitioning of 3D models. The partitioning is used to create variable level-of-detail (LOD) meshes, across both individual parts and assemblies, to provide a model suitable for access rights for individual actors within a collaborative design environment. We show how this technique can be used to implement a hierarchical set of security access privileges based on the Bellla Padula model. The partitioning is derived from a set of access specifications for an assembly model and its parts. The authors believe that this work is the first of its kind in the field of computer-aided design and collaborative engineering.
An Integrated Framework for Probabilistic Optimization Using Inverse Reliability Strategy
Authors: Du Xiaoping , Sudjianto Agus , Chen Wei
Published: June 2008

In this work, we propose an integrated framework for probabilistic optimization that can bring both the design objective robustness and the probabilistic constraints into account. The fundamental development of this work is the employment of an inverse reliability strategy that uses percentile performance for assessing both the objective robustness and probabilistic constraints. The percentile formulation for objective robustness provides an accurate probabilistic measure for robustness and more reasonable compound noise combinations. For the probabilistic constraints, compared to a traditional probabilistic model, the proposed formulation is more efficient since it only evaluates the constraint functions at the required reliability levels. The other major development of this work is a new search algorithm for the Most Probable Point of Inverse Reliability (MPPIR) that can be used to efficiently evaluate the performance robustness and percentile performance in the proposed formulation. Multiple techniques are employed in the MPPIR search, including the steepest decent direction and an arc search. The algorithm is applicable to general non-concave and non-convex functions of system performance with random variables following any continuous distributions. The effectiveness of the MPPIR search algorithm is verified using example problems. Overall, an engineering example on integrated robust and reliability design of a vehicle combustion engine piston is used to illustrate the benefits of the proposed method.
Product Platform Design and Optimization: Status and Promise
Authors: Simpson Timothy W.
Published: June 2008

In an effort to improve customization for today’s highly competitive global marketplace, many companies are utilizing product families to increase variety, shorten lead-times, and reduce costs. The key to a successful product family is the product platform from which it is derived either by adding, removing, or substituting one or more modules to the platform or by scaling the platform in one or more dimensions to target specific market niches. This nascent field of engineering design research has matured rapidly in the past decade, and this paper provides an extensive review of the research activity that has occurred during that time to facilitate product platform design and optimization. Techniques for identifying platform leveraging strategies within a product family are reviewed along with optimization-based approaches to help automate the design of a product platform and its corresponding family of products. Examples from both industry and academia are presented throughout the paper to highlight the benefits of platform-based product development, and the paper concludes with a discussion of promising research directions to help bridge the gap between planning and managing families of products and designing and manufacturing them.
Extracting Freeform Shape Information by Template Fitting
Authors: Song Y. , Vergeest J. S. M. , Dumitrescu R. , Wiegers T. , Wang C.
Published: June 2008

Finding effective and interactive tools for extracting freeform shape information continues to be a challenging problem in reverse engineering. Given a freeform shape, it may be constructed by adding one shape, named a pattern, to another. In this paper, an approach of extracting the pattern by template fitting is proposed. By similarity analysis, a user-defined region of interest in the shape can be matched, or fitted, to a shape template. According to the different methods in constructing the shape, several different kinds of R3 to R3 functions are defined. With those functions, the original shape is mapped to the fitted shape template, thus the template can be used as a “ruler” to measure the region of interest in the shape. The measuring results, e.g., the extracted pattern, can be generated through an inverse mapping, thus it can be used in the future design. Several implementations were conducted based on ACIS® and OpenGL® in order to verify the proposed method. It is also described how the proposed technique can be applied in practical shape modeling applications.
Development of a Design Reuse View of Cutting Tool Design Ontology
Authors: Roy R. , Bailey J. I. , Hodges R. G. L.
Published: June 2008

Knowledge attrition in the cutting tool industry can be mitigated and also the efficiency of the design process can be improved if past design solutions, which are the embodiment of rich expert knowledge, are made easily accessible to the designer for reuse. An effort is underway to realize this desirable situation at Widia Valenite, a company concerned with the design and manufacture of cutting tools. An ontology of cutting tool design exists, however this ontology is too detailed for designers who want quick access to past designs to satisfy new design problems. The potential of this ontology is only realized if a reuse view of the ontology is taken to retrieve design from a database of designs. This work presents the development and validation of the information requirements, in the form of descriptor terms, selected from the ontology for which designers make data entry that allows relevant past designs to be recalled. After these descriptor terms are identified, their success in recalling relevant past designs is demonstrated within a CBR application.
Approaches of Knowledge-Based Design
Authors: Vajna Sa´ndor
Published: June 2008

Knowledge-based design is a concept for the computer-aided provision and application of different representations of knowledge along the product development process. In this paper, a knowledge taxonomy is proposed, possible applications of knowledge-based design and the resulting benefits are discussed as well as open questions and research needs.
Emerging Virtual Machine Tools
Authors: Zaeh Michael F. , Wuensch Georg M. W. , Poernbacher Clemens , Ehrenstrasser Michael S. O.
Published: June 2008

In machine tool development, control software engineering has reached a cost proportion of over fifty percent of the total development costs. Highly customized user requirements and the compulsion to shorten development cycles accompany the need to master risen quality requirements of the mechatronic product machine tool. This enforces a strategy change from prevailing sequential engineering to concurrent engineering. The paper proposes a Hardware-in-the-Loop simulation environment as an interdisciplinary discussion platform to virtually implement, evaluate and optimize a machine tool throughout all stages of development.
An Efficient Algorithm for Constructing Optimal Design of Computer Experiments
Authors: Jin Ruichen , Chen Wei , Sudjianto Agus
Published: June 2008

Metamodeling approach has been widely used due to the high computational cost of using high-fidelity simulations in engineering design. The accuracy of metamodels is directly related to the experimental designs used. Optimal experimental designs have been shown to have good “space filling” and projective properties. However, the high cost in constructing them limits their use. In this paper, a new algorithm for constructing optimal experimental designs is developed. There are two major developments involved in this work. One is on developing an efficient global optimal search algorithm, named as enhanced stochastic evolutionary (ESE) algorithm. The other is on developing efficient algorithms for evaluating optimality criteria. The proposed algorithm is compared to two existing algorithms and is found to be much more efficient in terms of the computation time, the number of exchanges needed for generating new designs, and the achieved optimality criteria. The algorithm is also very flexible to construct various classes of optimal designs to retain certain structural properties.
A Study on the Use of Kriging Models to Approximate Deterministic Computer Models
Authors: Martin Jay D. , Simpson Timothy W.
Published: June 2008

The use of kriging models for approximation and global optimization has been steadily on the rise in the past decade. The standard approach used in the Design and Analysis of Computer Experiments (DACE) is to use an Ordinary kriging model to approximate a deterministic computer model. Universal and Detrended kriging are two alternative types of kriging models. In this paper, a description on the basics of kriging is given, highlighting the similarities and differences between these three different types of kriging models and the underlying assumptions behind each. A comparative study on the use of three different types of kriging models is then presented using six test problems. The methods of Maximum Likelihood Estimation (MLE) and Cross-Validation (CV) for model parameter estimation are compared for the three kriging model types. A one-dimension problem is first used to visualize the differences between the different models. In order to show applications in higher dimensions, four two-dimension and a 5-dimension problem are also given.
Towards a Conceptual Design Explorer Using Metamodeling Approaches and Constraint Programming
Authors: Yannou Bernard , Simpson Timothy W. , Barton Russell R.
Published: June 2008

Constraint Programming (CP) is a promising technique for managing uncertainty in conceptual design. It provides efficient algorithms for reducing, as quickly as possible, the domains of the design and performance variables while complying to the engineering and performance constraints linking them. In addition, CP techniques are suitable to graphically represent 3D projections of the complete design space. This is a useful capability for a better understanding of the product concept’s degrees of freedom and a valuable alternative to optimization based upon the construction of an arbitrary preference aggregation function. Unfortunately, one of the main impediments for using Constraint Programming on industrial problems of practical interest is that constraints must be represented by analytical equations, which is not the case of hard mechanical performances — such as meshing and finite element computations — that are usually obtained after lengthy simulations. We propose to use metamodeling techniques (MM) to generate approximated mathematical models of these analyses which can be employed directly within a CP environment, expanding the scope of CP to applications that previously could not be solved by CP due to the unavailability of analytical equations. We show that there is a tradeoff between the metamodel fidelity and the resulting CP constraint tractability. A strategy to find this compromise is presented. The case study of a combustion chamber design shows amazingly that the compromise is to favor the simplest and the coarsest first-order response surface model.
A New Approach to Minimisations for Shape Control During Free-Form Surface Deformation
Authors: Pernot Jean-Philippe , Guillet Ste´phane , Le´on Jean-Claude , Facidieno Bianca , Giannini Franca
Published: June 2008

Even if researches on free-form surface deformation have produced a lot of various methods, very few of them are able to really control the shape in an adequately interactive way and most of them propose a unique solution to the underconstrained system of equations coming out of their deformation models. In our approach, where the deformation is performed through the static equilibrium modification of a bar network coupled to the surface control polyhedron, different minimizations have been proposed to overcome these limits and form a set of representative parameters that can be used to give access to the desired shape. In this paper, a reformulation of the optimization problem is presented thus enabling the generation of new shapes based on a common set of minimization criteria. Such a modification widens the variety of shapes still verifying the same set of constraints. When generalizing some of these minimizations the user has access to a continuous set of shapes while acting on a single parameter. Taking advantage of the reformulation, anisotropic surface behaviors are considered too and briefly illustrated. In addition, the possibility of defining several minimizations on different areas of a surface is sketched and aims at giving the user more freedom in local shape definition. The whole minimizations proposed are illustrated through examples resulting from our surface deformation software.
Design Space Visualization and Its Application to a Design by Shopping Paradigm
Authors: Stump Gary M. , Yukish Mike , Simpson Timothy W. , Harris E. Nathan
Published: June 2008

We have developed a data visualization interface that facilitates a design by shopping paradigm, allowing a decision-maker to form a preference by viewing a rich set of good designs and use this preference to choose an optimal design. Design automation has allowed us to implement this paradigm, since a large number of designs can be synthesized in a short period of time. The interface allows users to visualize complex design spaces by using multi-dimensional visualization techniques that include customizable glyph plots, parallel coordinates, linked views, brushing, and histograms. As is common with data mining tools, the user can specify upper and lower bounds on the design space variables, assign variables to glyph axes and parallel coordinate plots, and dynamically brush variables. Additionally, preference shading for visualizing a user’s preference structure and algorithms for visualizing the Pareto frontier have been incorporated into the interface to help shape a decision-maker’s preference. Use of the interface is demonstrated using a satellite design example by highlighting different preference structures and resulting Pareto frontiers. The capabilities of the design by shopping interface were driven by real industrial customer needs, and the interface was demonstrated at a spacecraft design conducted by a team at Lockheed Martin, consisting of Mars spacecraft design experts.
Optimization for Mass Variation of System Including Shock Absorber
Authors: Koganei Reiko , Maemori Ken’ichi
Published: June 2008

We present an optimization method of shock absorbers for analyzing the effect of mass variation of an impacting body on the response of a system including the shock absorber, such as landing gears of aircraft, elevators and coupling devices for railroad cars. The system including the optimum semi-active shock absorber is compared with those including two kinds of optimum passive shock absorbers regarding the variation of the acceleration of the impacting body. The maximum value and each of the maximum accelerations of the different masses of the impacting body are set as objective functions to be minimized, respectively. The design variables of these optimizations are reciprocals of resisting coefficients of the shock absorber. As a result of the optimizations, it is clarified that the optimum semi-active shock absorber can cope with the mass variation of the impacting body better than the optimum passive shock absorbers.
Improved Development Cycle of a Compliant Manipulator
Authors: Canfield Stephen L. , Hull Patrick V. , Beard James W.
Published: June 2008

Application of the compliant design methodology to manipulators has held the promise of delivering manipulators with many significant advantages, including low cost, small size, low backlash and friction, and high positioning accuracy. This approach has been demonstrated in part by Canfield et. al., [1] to a class of three-degree-of-freedom manipulators based on a specific parallel architecture topology. In [1], the authors’ intent was to develop two compliant manipulators that exhibit several of the features associated with compliant devices. However, upon review of the manipulators resulting from this work it is observed that many of the benefits that were expected were lost at some point in the design process, resulting in manipulators that were large, expensive and suffered significantly from required assembly and inaccuracies in manufacture. This paper will revisit the problem addressed in [1], using the modeling tools demonstrated in that paper but will present several improved development measures that will result in manipulators that exhibit multiple features promised by compliant devices. The resulting manipulators will then be compared against the manipulators from [1] with a summary of the performance and characteristics of each given and evaluated.
On the Existence of Special Cases of Input Speed Doubling Linkage Mechanisms
Authors: Rastegar J. , Zhang J. , Hua L.
Published: June 2008

A special class of planar and spatial linkage mechanisms is presented in which for a continuous full rotation or continuous rocking motion of the input link, the output link undergoes two continuous rocking motions. In a special case of such mechanisms, for periodic motions of the input link with a fundamental frequency ω, the output motion is periodic but with a fundamental frequency of 2ω. In this paper, the above class of linkage mechanisms are referred to as speed-doubling linkage mechanisms. Such mechanisms can be cascaded to provide further doubling of the fundamental frequency (rocking motion) of the output motion. They can also be cascaded with other appropriate linkage mechanisms to obtain crank-rocker or crank-crank type of mechanisms. The conditions for the existence of speed-doubling linkage mechanisms are provided and their mode of operation is described in detail. Such speed-doubling mechanisms have practical applications, particularly when higher output speeds are desired, since higher output motions can be achieved with lower input speeds. Such mechanisms also appear to generally have force transmission and dynamics advantages over regular mechanisms designed to achieve similar output speeds.
Choosing the Optimal Contact Force Distribution for Multi-Limbed Mobile Robots With Three Feet Contact
Authors: Hong Dennis W. , Cipra Raymond J.
Published: June 2008

One of the inherent problems of multi-limbed mobile robotic systems is the problem of multi-contact force distribution; the contact forces and moments at the feet required to support it and those required by its tasks are indeterminate. A new strategy for choosing an optimal solution for the contact force distribution of multi-limbed robots with three feet in contact with the environment in three-dimensional space is presented. The optimal solution is found using a two-step approach: first finding the description of the entire solution space for the contact force distribution for a statically stable stance under friction constraints, and then choosing an optimal solution in this solution space which maximizes the objectives given by the chosen optimization criteria. An incremental strategy of opening up the friction cones is developed to produce the optimal solution which is defined as the one whose foot contact force vector is closest to the surface normal vector for robustness against slipping. The procedure is aided by using the “force space graph” which indicates where this solution is positioned in the solution space to give insight into the quality of the chosen solution and to provide robustness against disturbances. The “margin against slip with contact point priority” approach is also presented which finds an optimal solution with different priorities given to each foot contact point for the case when one foot is more critical than the other. Examples are presented to illustrate certain aspects of the method and ideas for other optimization criteria are discussed.
An Integrated Design Optimization Approach for Quantitative and Qualitative Search Space
Authors: Oduguwa Victor , Roy Rajkumar , Farrugia Didier
Published: June 2008

Most of the algorithmic engineering design optimisation approaches reported in the literature aims to find the best set of solutions within a quantitative (QT) search space of the given problem while ignoring related qualitative (QL) issues. These QL issues can be very important and by ignoring them in the optimisation search, can have expensive consequences especially for real world problems. This paper presents a new integrated design optimisation approach for QT and QL search space. The proposed solution approach is based on design of experiment methods and fuzzy logic principles for building the required QL models, and evolutionary multi-objective optimisation technique for solving the design problem. The proposed technique was applied to a two objectives rod rolling problem. The results obtained demonstrate that the proposed solution approach can be used to solve real world problems taking into account the related QL evaluation of the design problem.
Systematic Life Cycle Design for Sustainable Product Development
Authors: Lu B. , Gu P.
Published: June 2008

Sustainable product development (SPD) requires that product design achieves minimum or zero environmental impact, in addition to satisfying the traditional design criteria such as product functionality, quality, features, costs and time to market. Therefore, the environmental evaluations must be incorporated into design stage. In this research, a product design process model was proposed which includes three design requirements, two design tasks, and three comprehensive assessment streams. The functional requirement is derived from the customer needs to reflect the product’s functional purpose; the environmental requirement reflects the society’s needs of protecting natural resources and environment; and the economic requirement is to ensure the company’s basic business goals. Accordingly, SPD aims to simultaneously carry out two tasks of designing products’ physical structures and lifecycle structures. In the assessment phase of product design, three assessment streams, lifecycle quality (LCQ) analysis, lifecycle assessment (LCA), and lifecycle cost (LCC) are conducted with respect to the functional, environmental, and economic evaluations. A Process-Based Analysis concept is proposed for analysis of all three dimensions of LCQ, LCA, and LCC evaluations. Simplified LCA was used for environmental evaluations. The detailed assessment techniques are also developed for effective design evaluations. A case study will be provided to illustrate the methods and models.
The Vectorial Parameterization of Motion
Authors: Bauchau Olivier A. , Choi Jou-Young
Published: June 2008

This paper presents a vectorial parameterization of motion that generalizes the vectorial parameterization of rotation. The Pl¨ucker coordinates of an arbitrary material line of a rigid body subjected to a screw motion are shown to transform by the action of a motion tensor. The proposed vectorial parameterization completely describes an arbitrary motion by means of two vectors that constitute an eigenvector of the motion tensor associated with its positive unit eigenvalue. The first vector is conveniently selected as the vectorial parameterization of rotation, and the second is related to the displacement of a point of the rigid body. A complete description of motion is presented in terms of a generic vectorial parameterization. Relevant formulæ for specific parameterizations of this class can then be easily obtained. More details are given for three parameterizations that present desirable properties: the Euler, Cayley-Gibbs-Rodrigues, and Wiener-Milenkovic motion parameters.
Studies on the Stiffness Properties of the Absolute Nodal Coordinate Formulation for Three-Dimensional Beams
Authors: Sopanen Jussi T. , Mikkola Aki M.
Published: June 2008

The objective of this study is to investigate the accuracy of elastic force models that can be used in the absolute nodal coordinate finite element formulation for the analysis of threedimensional beams. The elastic forces of the absolute nodal coordinate formulation can be derived using a continuum mechanics approach. This study investigates the accuracy and usability of such an approach for the three-dimensional absolute nodal coordinate beam element. This study also presents an improvement proposal for the use of a continuum mechanics approach in deriving the expression of the elastic forces of the beam element. The improvement proposal is verified using several numerical examples. Numerical examples show that the proposed elastic force model of the beam element agrees with analytical results as well as with solutions obtained using existing finite element formulation. The results also imply that the beam element does not suffer from the phenomenon called shear locking. In the beam element under investigation, global displacements and slopes are used as the nodal coordinates, which resulted in a large number of nodal degrees of freedom. This study provides a physical interpretation of the nodal coordinates used in the absolute nodal coordinate beam element. It is shown that the beam element based on the absolute nodal coordinate formulation relaxes the assumption of the rigid cross-section and is capable of representing a distortional deformation of the cross-section.
Multibody Inverse Dynamics Using an Energy Preserving Direct Transcription Process
Authors: Bottasso Carlo L. , Croce Alessandro
Published: June 2008

We propose a procedure for the solution of inverse multibody dynamic problems, here intended as optimal control problems for dynamical systems governed by differential-algebraic equations. The numerical solution is obtained by a direct transcription process based on an energy preserving scheme that ensures nonlinear unconditional stability. The resulting finite-dimensional problem is solved by sequential quadratic programming. We test the proposed methodology with the help of representative examples.
A New Method for the Path Planning of an In-Pipe Inspection Robot
Authors: Artigue Vincent , Pascal Madeleine
Published: June 2008

A mobile robot designed for in-pipe inspection is considered. The robot consists of a cylindrical body with six links, each ended by a driven wheel. For each link, a spring connected to a jack (prismatic joint) is used to push the wheel against the wall of the pipe. The robot is actuated by DC motors applied on the wheels. The aim of the study is to define the trajectory of the robot in a curved pipe. Several experiments have shown that in this case, the robot may be stopped in some parts of the elbows. The path planning is performed assuming that the robot motion is very slow. An energetic method is used in order to detect the locking zones, and to define the best trajectories avoiding these locking phenomena.
General Dynamic Model of Flexible Multi-Body Systems With Its Application in Gun Systems
Authors: Yang GuoLai , Chen Yunsheng
Published: June 2008

General purpose software for kinematic and dynamic simulation of flexible multi-body systems is serviced widely to practical engineering fields. In this paper general dynamic model of flexible multi-body systems with its application in gun systems is set up vie Kane’s equation. The “0-1” method is presented for calculating partial velocities, partial angular velocities and coefficients matrix of the differential equations of motion. Techniques of automatic modeling for dynamic analysis of flexible multi-body systems of gun systems are introduced in this paper, which include automatic identification of systems configuration, automatic determination of degrees of freedom, automatic derivation of kinematic formulas, automatic application of load, automatic generation and solution of motion equations and so on. Because of automatic modeling, overelaborate procedures are avoided, and model on general purpose is realized, which can be conveniently used in dynamic simulation for launching process of gun systems and validly applied to design of them. Finally, a numerical example is given to demonstrate the feasibility of general algorithms proposed.
Internal Variable Models of Viscoelasticity With Fractional Relaxation Laws
Authors: Hanyga A.
Published: June 2008

Internal parameters are used primarily as a numerically convenient surrogate of hereditary formulation of dispersive media. They are however also helpful in combining hereditary and nonlinear effects. Geometrical nonlinearity and the structure of strain invariants imply that nonlinearity has to be contemplated at all levels, including the relaxation equations satisfied by the internal parameters. An obvious application is viscosity of rubber and polymers.
Dynamics of Infinite Beams Described by Fractional Time Derivatives
Authors: Ruge Peter , Trinks Carolin
Published: June 2008

Closed-form solutions of infinite Bernoulli-Euler beams on a viscoelastic foundation are available for harmonic excitations with frequency Ω. For more general time-dependent loadings and beam-systems with local perturbations, for example caused by non-linear effects an overall treatment of the system in the time-domain is highly appropriated. Here the analytical dynamic stiffness of the infinite beam in the frequency-domain is approximated by a rational polynomial in the low frequency-domain and by an irrational part representing the asymptotic behaviour for Ω tending towards infinity. Thus, the corresponding description in the time-domain contains a fractional time derivative part and additonal internal variables due to splitting the rational polynomial into a linear system with respect to Ω.
Nonlinear Simulation Analysis and Experiment of Fluid Plain Journal Bearing With Incompressible Fluid
Authors: Fujita Katsuhisa , Shintani Atsuhiko , Yoshioka Koji , Okuno Kouhei , Tanaka Hiroaki , Asaida Yasuhiro , Saito Hiroaki
Published: June 2008

Recently, in many areas such as computers and information equipments etc., the fluid journal bearings are required to rotate at higher speed. To satisfy this requirement, the strictly stability analysis of the journal is indispensable. In this paper, we investigate the stability analysis of the dynamic behavior of the fluid plain journal bearing with an incompressible fluid considering the nonlinear terms of fluid forces. The stability analysis is examined by the numerical simulations on each model of a rigid rotor and a flexible rotor. The stable regions by nonlinear analysis are compared with the regions by classical linear analysis. Performing the nonlinear simulation analysis, it becomes clear that there is rather a stable region which amplitude does not grow up abruptly, and this phenomenon can not only be pointed out, but also is judged to be unstable by linear stable analysis. Finally, the experiment using actual bearings is performed and compared with the numerical results.