bluuebunny/crossref_metadata_2025 huggingface dataset:
Artificial Intelligence Based Inference Techniques for Automated Process Planning for Machined Parts
Authors: Deb Sankha , Ghosh Kalyan
Published: June 2008

Many areas of research in manufacturing are increasingly turning to applications of Artificial Intelligence (AI). The problem of developing inference strategies for automated process planning in machining is one such area of successful application of AI based approaches. Given the high complexity of the process planning expertise, development of inference techniques for automated process planning is a big challenge to researchers. The traditional inference methods based on variant and generative approaches using decision trees and decision tables suffer from a number of shortcomings, which have prompted researchers to seek alternative approaches and turn to AI for developing intelligent inference techniques. In this article, we have reviewed, categorized and summarized the research on applications of AI for developing inference methods for automated process planning systems. We have described our ongoing research work on developing an intelligent inference strategy based on artificial neural networks for implementing machining process selection for rotationally symmetric parts.
Human Head Aesthetic Design Using Hybrid Genetic Algorithm
Authors: Xu Zhi Gang , Li JianFeng
Published: June 2008

In this paper a paradigm of human head aesthetic design based on hybrid genetic algorithm is proposed. Hybrid means the integration of interactive and natural selection of the population in genetic algorithm during the evolution process. Firstly, a sketching paradigm is proposed to sketch the head profile by mouse input, the profile is then parameterized and modified; quantities of more profiles are generated based on GA optimizer, where the user can select the best one. After 2D profile design, a 3D reconstitution algorithm is developed to construct the 3D head in NURBS model by analyzing four input sketching curves, i.e. one longitudinal curve, three side profile curves. The 3D head mesh model is capable of modification and easy to be manipulated. The prototype CAD system is developed based on ACIS 3D modeling kernel, and the design result is illustrated to show the effectiveness of this paradigm.
Mini-Max Type Formulation of Strict Robust Design Optimization Under Correlative Variation
Authors: Hirokawa Noriyasu , Fujita Kikuo
Published: June 2008

This paper proposes a mini-max type formulation for strict robust design optimization under correlative variation based on design variation hyper sphere and quadratic polynomial approximation. While various types of formulations and techniques have been developed for computational robust design, they confront the compromise among modeling of parameter variation, feasibility assessment, definition of optimality such as sensitivity, and computational cost. The formulation of this paper aims that all points within the distribution region are thoroughly optimized. For this purpose, the design space with correlative variation is diagonalized and isoparameterized into a hyper sphere, and the functions of nominal constraints and the nominal objective are modeled as quadratic polynomials. These transformation and approximation enable the analytical discrimination of inner or boundary type on the worst design and its quantified values with less computation cost under a certain condition, and bring the procedural definition of the strictly robust optimality of a design as a maximization problem. The minimization of this formulation, that is, mini-max type optimization, can find the robust design under the above meaning. Its validity is ascertained through numerical examples.
Optimization of Machine System Designs Using Hierarchical Decomposition Based on Criteria Influence
Authors: Yoshimura Masataka , Izui Kazuhiro , Komori Shigeaki
Published: June 2008

Machine product designs routinely have so many mutually related characteristics that common design optimization methods often result in an unsatisfactory local optimum solution. In order to overcome this problem, this paper proposes a design optimization method based on the clarification of the conflicting and cooperative relationships among the characteristics. First of all, each performance characteristic is divided into simpler basic characteristics according to its structure. Next, the relationships among the basic characteristics are systematically identified and clarified. Then, based on this clarification, the optimization problem is expressed using hierarchical constructions of these basic characteristics and design variables related to the most basic characteristics. Finally, an optimization strategy and detailed hierarchical optimization procedures are constructed, after clarifying the influence levels of each basic characteristic upon the objective functions and setting a core characteristic for the product under consideration. Here, optimizations are sequentially repeated starting with the basic optimal unit group at the bottom hierarchical level and proceeding to higher levels by the hierarchical genetic algorithms. Then, the Pareto optimum solutions at the top hierarchical level are obtained. With the proposed optimization methods, optimization can be more easily applied after the optimization problems have been simplified by decomposition. In doing so, the volume of design spaces for each optimization is reduced, while useful and unique rules and laws may be uncovered. The optimization strategy expressed by the hierarchical structures can be used for the optimization of similar product designs, which realize these breakthroughs, yielding improved product performances. The proposed method is applied to a machine-tool structural model.
Automatic Conceptual Design of Mechanical Devices Based on Reasoning the Design Rules
Authors: Wang Yu-Xin , Wang Li-jun
Published: June 2008

This paper presents an automatic method for conceptual design of mechanical devices by embodying the functions to the graph carrier according to the design rules. Through “and”, “or”, “no” logical calculations, and “adjacency”, “overlap”, “topology” relation calculations among the basic fimctional forms supplied in this paper, the design rules can be defined. Since the design rule only reflects the logical relationships among the basic function forms, it is easily to be carried out by computers. By introducing imaginary function forms and defining special basic function forms, the system can deal with the conceptual design problem for complex mechanical devices. Comparing with enumerating manually method, by doing strict similarity analysis of links of graph carrier and exact logical calculation among basic functional forms, our method can efficiently avoid producing redundance schemes and missing suitable results, and will get all suitable results. The research has shown that the conceptual design results obtained by combination of basic simple mechanisms belong to a subset of the results group obtained by the method presented in this paper. The most prominent advantage of our method presented in this paper is that by refining the design rules, the conceptual design process is convergent, and optimal conceptual design solutions are available.
A Study on Collaborative Design Considering Features of Design
Authors: Miyashita Tomoyuki , Yamakawa Hiroshi
Published: June 2008

In design processes of machinery, much computer software, for examples CAD/CAE/CAM software, are used. The design processes are aided by this software. The seamless connections of the design processes are necessary for the improvement of the cost benefit of the products. However, sometimes, the conflicts among designs or design processes are occurred by the change of the design at a certain design process and these conflicts are should be noticed and solved immediately. In this research, we have developed the design system including CAD software and the developed system has some functions to find the conflicts of the change of designs and to solve the conflicts. We use Data Envelopment Analysis (DEA) to calculate the efficiency of the design and Satisficing Trade-off Method (STM) to find and solve the conflicts. We have confirmed through some fundamental numerical examples and discussed of the proposed system and method and showed the effectiveness of out study.
Development of Multi-Stage and Hybrid Real-Coded Genetic Algorithms With Active Constraints
Authors: Mimura Yasunari , Yoshimura Shinobu , Hiroyasu Tomoyuki , Miki Mitsunori
Published: June 2008

In this study, we propose multi-stage and hybrid real-coded genetic algorithm. In the proposed algorithm, there are two stages. In the first stage, Real-coded Genetic Algorithm with Active Constraints (RGAAC) is applied to find a solution that is close to the global optimum. In RGAAC, indviduals who are out of the feasible region are pulled back into feasible region. Therefore, the effective search can be carried out even in the constraints problems. In the second stage, Feasible Region Limiting Method (FRLM) is applied to obtain an optimum solution. FRLM uses the solution that is derived in the first stager as an initial point. In this study, RGAAC is applied to solve the truss structure problems. Through these problems, the effectiveness and the searching mechanism of RGAAC is discussed. The, the proposed algorithm is also applied to 2D problem. In this problem, there are about 1000 design variables. The proposed method can derive the reasonable solution. From these results, it is concluded that the proposed method is effective to solve optimzation problems of large scale structures.
Stiffness Testing of Hydraulic Hoses
Authors: Chipperfield Kurt A. , Vance Judy M.
Published: June 2008

Hydraulic hoses are used in industrial machines to transmit power. These hoses have a physical stiffness that depends upon the hose size and type. If a computer model is used to predict the path a hose will take through a machine, accurate physical stiffness properties are required for the hose. These stiffness properties are not available from hose manufacturers and hose test methods are scarce in the available literature. This paper describes methods used for testing the bending stiffness, torsion stiffness, and axial stiffness of hydraulic hoses. Plots of the stiffness data are given for a sample hose.
Integration of Commercial CAD/CAM System With Custom CAPP Using Orbix Middleware and CORBA Standard
Authors: Rangel Fernando , Shah Jami J.
Published: June 2008

This paper discusses the issues of integrating the Computer-Aided Design (CAD) and Computer-Aided Manufacturing (CAM) programs in commercial software. Integration was achieved through implementation of a computer-aided process planning (CAPP) system within the commercial software. The part model was imported into, or designed in, the commercial CAD system. Manufacturing information was then extracted from the part model by the CAPP system using commercial Application Programming Interfacing (API) methods. The CAPP system then uses the extracted information to produce a process plan consistent with the requirements of the commercial CAM module to produce Numerical Control (NC) code. The internal integration was accomplished using commercial API methods that dynamically bind the CAD, CAPP, and CAM into a single continuous application. These APIs are implemented using the Orbix middleware following the CORBA standard. A case study demonstrating the integration is presented. Strengths and weaknesses of integrating the CAD and CAM domains using APIs and middleware are discussed.
Math-Based Performance Evaluation of an Experimental Car: Side Impact Protection
Authors: Deng Yih-Charng , Lin Chin-Hsu , Wang J. T.
Published: June 2008

This study used finite element models to assess potential benefits of selected unconventional features implemented in this study for occupant protection in side impact. These features include door lockdown, gullwing door with a corrugated aluminum panel and cross-car beams. The intrusion and intrusion velocity of the B-pillar were used as the parameters for measuring side impact protection performance. No attempt was made here to assess manufacturablity, design feasibility, mass implications or market interest.
Empirical Analysis Using Advanced Similarity Methods
Authors: Wood John J. , Wood Kristin L. , Troxell Wade O.
Published: June 2008

Traditional dimensional analysis techniques for predicting the performance characteristics of a product can be greatly improved in both accuracy and domain of applicability by the infusion of empirical data, derived from material tests, into the equations that characterize the system parameters of interest. Advanced similarity methods are investigated which overcome the constraints associated with the traditional methods and provide increased analysis capability and improved insight into the phenomenon governing the problem. Such capability greatly increases the design toolbox available to product developers, across a large range of scale and application. It also significantly enhances a developer’s choices for prototype portioning during a development cycle. Solid mechanics and heat transfer applications are used to illustrate the basic utility of the methods.
An Analytical Approach to Functional Design
Authors: Wang Kai-Lu , Jin Yan
Published: June 2008

Functional design is a process in engineering design that dominates the key features of the result to be developed. Designing good functions that both satisfies the requirements and leads to better results is a challenge due to uncertainties on the consequences of the selected functions, and the lack of analysis methods for identifying the properties of function structures. Therefore, extensive experiences are usually required for functional design. This research argues that the physical relationships among the resulting components of a design are the consequences of functional dependencies developed during the functional design process. Therefore based on the understanding of functions and functional dependencies, a reasoning procedure can be developed to predict the performance properties of the design so that the effectiveness of the functional design can be evaluated at an early design stage. This paper proposes a dependency-based function modeling and analysis method that can be applied to represent and assess functions and function structures at the functional design stage. Designers can predict the properties of the functions they designed without having to have similar design experiences. An application software is also developed to implement the method and demonstrate its effectiveness.
Decomposition-Based Assembly Synthesis for In-Process Dimensional Adjustability
Authors: Lee Byungwoo , Saitou Kazuhiro
Published: June 2008

This paper presents a method of assembly synthesis focused on the in-process adjustability, where assembly synthesis is defined as the decomposition of the end product design prior to the detailed component design phase. Focusing on the effect of joint configurations on dimensional integrity of complex assemblies, the method recursively decomposes a product configuration and assigns joint configurations according to simple rules, in order to achieve a designed dimensional adjustability and non-forced fit. The rules employed during the decomposition process are drawn from the previous works of assembly design. An augmented AND/OR graph is utilized to represent a process of assembly synthesis with the corresponding assembly sequences, and the algorithm for generating the AND/OR graph is discussed. The method is applied to two dimensional skeletons of product designs at very early stage of the design process. The relation of the assembly synthesis to Datum Flow Chain (Mantripragada and Whitney, 1998) is discussed. It is also shown that each final design from the assembly synthesis defines its own Datum Flow Chain.
Knowledge Intensive Support for Product Family Design
Authors: Zha Xuan F. , Lu Wen F.
Published: June 2008

This paper presents an on-going research effort on platform-based product family design using a knowledge intensive support paradigm. The background research related to product family design is first reviewed. Then, the fundamental issues underlying the product family design are discussed. A module-based integrated product family design scheme is proposed with knowledge support for customer requirements’ modeling, product architecture modeling, product platform establishment, product family generation, and product assessment. The systematic methodology and the relevant technologies are investigated and developed for knowledge modeling and support in the product family design process. An information and knowledge-modeling framework is developed for the module-based product family design scheme. The issues and requirements related to develop knowledge intensive support system for module-based product family design are also addressed. Finally, a case study on knowledge support for power supply family design and evaluation is provided for illustration.
A Hybrid Approach to Feature Recognition Using Approximate and Partial Exact CAD Models
Authors: Belludi Nagesh , Yip-Hoi Derek
Published: June 2008

Several CAD system independent feature recognition techniques have been developed to drive manufacturing applications. Commercial implementations of these techniques require translating CAD models using STEP or other neutral file formats. With large CAD models found in some application domains; e.g., powertrain machining, corresponding STEP files are also large. This leads to large processing times. Another approach is to use lightweight formats such as STL or VRML. Here, complete & accurate parameter extraction is difficult because these formats approximate surfaces as tessellations. This paper discusses a new methodology for feature recognition, in which a VRML file is used for feature identification. To some extent, parameters of faces with simple surface-types are recovered from the tessellated model. If identified features consist of faces whose parameters are not recovered from the tessellated model, a partial STEP file translation is used for extracting exact parameters. This CAD system independent algorithmic development and implementation reduces the amount of data exported to neutral files, thus leading to more efficient feature recognition.
A Mesh Feature Paradigm for Rapid Generation of CAE-Based Design of Experiments Data
Authors: Chen Yifan , Stewart Paul , Marsan Anne , Mo Huaicai , Tonshal Basavaraj
Published: June 2008

CAE-Based simulation and Design of Experiments (DoE) are becoming mature and increasingly effective in development of complex industrial products such as automobiles. We present in this paper a CAE mesh-modeling paradigm that ultimately led to fast, automatic generation of a family of meshes based on a base design. This paradigm is hinged on the so-called mesh features to achieve productivity for modeling CAE meshes. Mesh features are self-contained mesh deformation operations that are context-free, stored separately from the base model, and can be applied to the model in a proper mix at any time. Libraries of mesh features can also be established to archive useful features for future use. Furthermore, by assigning mesh features for DoE factors, one can specify for the system the proper way to assemble features and apply them automatically to the base model to generate input meshes for a DoE study. Automatic generation of a family of DoE input meshes results in maximum time savings and minimum chances for errors, especially for applications involving large-scale CAE models.
Error Sensitivity Analysis for Optimal Calibration of Parallel Kinematic Machines
Authors: Xi Fengfeng , Verner Marcel , Mechefske Chris
Published: June 2008

In this paper, error sensitivity analysis is discussed for the purpose of optimal calibration of parallel kinematic machines (PKMs). The idea is to find a less error sensitive area in the workspace for calibration. To do so, an error model is developed that takes into consideration all the geometric errors due to imprecision in manufacturing and assembly. Based on this error model, it is shown that the error mapping from the geometric errors to the pose error of the PKM depends on the Jacobian inverse. The Jacobian inverse would introduce spurious errors that would affect the calibration results, if used without proper care. Hence, it is suggested to select the areas in the workspace with smaller condition numbers for calibration. A case study is presented to illustrate the proposed method.
On the Entropy of Multi-Objective Design Optimization Solution Sets
Authors: Farhang-Mehr Ali , Azarm Shapour
Published: June 2008

In this paper, an entropy-based metric is presented for quality assessment of non-dominated solution sets obtained from a multiobjective optimization technique. This metric quantifies the ‘goodness’ of a solution set in terms of its distribution quality over the Pareto-optimal frontier. Therefore, it can be useful in comparison studies of different multi-objective optimization techniques, such as Multi-Objective Genetic Algorithms (MOGAs), wherein the capabilities of such techniques to produce and maintain diversity among different solution points are desired to be compared on a quantitative basis. An engineering test example, the multiobjective design optimization of a speed-reducer, is presented in order to demonstrate an application of the proposed entropy metric.
Design Optimization for Structural-Acoustic Problems Using FEM-BEM
Authors: Choi Kyung K. , Dong Jun , Kim Nam Ho
Published: June 2008

A structural-acoustic design optimization of a vehicle is presented using finite element and boundary element analyses. The steady-state dynamic behavior of the vehicle is calculated from the finite element frequency response analysis, while the sound pressure level within the acoustic cavity is calculated using the boundary element analysis. A reverse solution procedure is employed for the design sensitivity calculation using the adjoint variable method. An adjoint load is obtained from the acoustic boundary element re-analysis, while the adjoint solution is calculated from the structural dynamic re-analysis. The evaluation of pressure sensitivity only involves a numerical integration process for the structural part. Two design optimization problems are formulated and solved. It has been shown that the structural weight is saved when the noise level is maintained, and the weight needs to increase in order to reduce the noise level in the passenger compartment.
The Evolution of a Layered Manufacturing Interchange Format
Authors: McMains Sara , Smith Jordan , Se´quin Carlo
Published: June 2008

Over the last several years we have developed the Berkeley Solid Interchange Format (SIF) for layered manufacturing data exchange. By building both design software that outputs SIF as well as manufacturing software that processes the SIF input files, we gained insights into the concerns of both sides of data exchange — insights which often led to major changes in successive versions of the format. In this paper, we share some of the most important lessons we learned (many of which are applicable to all geometric data exchange, not merely for layered manufacturing) and explain how they shaped SIF.
H-ISM: An Implementation of Heterogeneous Implicit Solid Modeling
Authors: Wahlborg Justin , Ganter Mark A. , Schwartz Daniel T. , Storti Duane
Published: June 2008

This paper discusses implementation of an implicit solid modeling approach to the representation of heterogeneous objects, i.e. solids whose material composition is not uniform. We present a brief review of related literature and then focus on implementation of heterogeneous implicit solid modeling (H-ISM) using a computer algebra system. Several heterogeneous implicit solid models of multi-material objects from standard part catalogues are presented to demonstrate the effectiveness of H-ISM implementation.
Bayesian Evaluation of Engineering Models
Authors: Chandrashekar Natesh , Krishnamurty Sundar
Published: June 2008

This paper deals with the development of simulation-based design models under uncertainty, and presents an approach for building surrogate models and validating them for their efficacy and relevance from a design decision perspective. Specifically, this work addresses the fundamental research issue of how to build such surrogate models that are computationally efficient and sufficiently accurate, and meaningful from the viewpoint of its subsequent use in design. Towards this goal, this work presents a Bayesian analysis based iterative model building and model validation process leading to reliable and accurate surrogate models, which can then be invoked in the final design optimization phase. The resulting surrogate models can be expected to act as abstractions or idealizations of the engineering analysis models and can mimic system performance in a computationally efficient manner to facilitate design decisions under uncertainty. This is accomplished by first building initial models, and then refining and validating them over many stages, in line with the iterative nature of the engineering design process. Salient features of this work include the introduction of a novel preference-based design screening strategy nested in an optimally-selected prior information set for validation purposes; and the use of a Bayesian evaluation based model-updating technique to capture new information and enhance model’s value and effectiveness. A case study of the design of a windshield wiper arm is used to demonstrate the overall methodology and the results are discussed.
Evaluation of Conceptual Designs and Maintainability Incorporating Uncertainty
Authors: Kalenchuk D. , Gu P.
Published: June 2008

This paper presents a method for carrying out a quantitative evaluation of design concepts with incomplete assessment information. When evaluating design solutions, in addition to consideration of product functionality, quality and cost, product life cycle performance such as maintainability should also be evaluated. Product maintainability issues are one of the more difficult design aspects to evaluate in early design stage. This paper describes specific maintainability metrics for evaluating product maintenance of conceptual design alternatives. Because of the uncertainty associated in early stage design evaluation, the varying degree of customer expectation must be incorporated into the evaluation system. Non-traditional fuzzy sets are used to represent expectations of the customer and compare them to design solution parameters. A case study is presented to illustrate the design method.
A Scheme for Transformation of Tolerance Specifications to Generalized Deviation Space for Use in Tolerance Synthesis and Analysis
Authors: Wang H. , Pramanik N. , Roy U. , Sudarsan R. , Sriram R. D. , Lyons K. W.
Published: June 2008

Traditionally tolerances for manufactured parts are specified using symbolic schemes as per ASME or ISO standards. To use these tolerance specifications in computerized tolerance synthesis and analysis, we need information models to represent the tolerances. Tolerance specifications could be modeled as a class with its attributes and methods [ROY01]. Tolerances impose restrictions on the possible deviation of features from its nominal size/shape. These variations of shape/size of a feature could be modeled as deviation of a set of generalized coordinates defined at some convenient point on the feature [BAL98]. In this paper, we present a method for converting tolerance specifications as per MMC (Maximum Material Condition) / LMC (Least Material Condition) / RFS (Regardless of Feature Size) material conditions for standard mating features (planar, cylindrical, and spherical) into a set of inequalities in a deviation space for representation of deviation of a feature from it’s nominal shape. We have used the virtual condition boundaries (VCB) as well as tolerance zones (as the case may be) for these mappings. For the planar feature, these relations are linear and the bounded space is diamond shaped. For the other cases, the mapping is a set of nonlinear inequalities. The mapping transforms the tolerance specifications into a generalized coordinate frame as a set of inequalities. These are useful in tolerance synthesis, and analysis as well as in assemblability analysis in the generalized coordinate system (deviation space). In this paper, we also illustrate the mapping procedures with an example.
Concurrent Product Design: A Case Study on the Pico Radio Test Bed
Authors: Odell Daniel L. , Wright Paul K.
Published: June 2008

This paper presents a case study on the mechanical design and fabrication of the Pico Radio Test Bed: a wireless networking node for experimentation with applications, networking, media access layer design, and position locating algorithms. Particular focus is placed on the systematic design process and resolving coupling design constraints between the mechanical and electrical domains. Three generations of the design are presented to demonstrate the evolution of the design as conflicts arose, problems were noticed, and requirements changed.
Design of a New Feed-Deposition Head for Robotized Filament Winding
Authors: Carrino L. , Polini W. , Sorrentino L.
Published: June 2008

This work deals with the design of a new feed and deposition head for a robotized cell able to manufacture complex shape parts in composite material by means of the filament winding technology. The adopted criteria aim to increase both the filament winding efficiency and the composite part quality by designing a system able to control the process parameters, such as the roving tension, the winding speed and the winding trajectory through a very compact and flexible frame, that presents in a single solution the pinboard, the roving tensioner, the roving-guide system and the deposition head. Moreover, the same frame is able to satisfy manufacturing and assembling requirements. Finally, the new proposed system has been designed in such a way as to be easily adaptable to every robot or machine used to wind, since it has a flange that may be easily connected with the robot end-effector by warranting a high precision and a high repeatability of the roving locating during the winding process. The new head working and its interaction with the most critical process parameters have been evaluated through experimental tests. This work belongs to a research project aiming to develop an integrated environment for winding complex shape parts through a robotized cell.
Towards Failure Modeling in Complex Dynamic Systems: Impact of Design and Manufacturing Variations
Authors: McAdams Daniel A. , Tumer Irem Y.
Published: June 2008

When designing vehicle vibration monitoring systems for aerospace devices, it is common to use well-established models of vibration features to determine whether failures or defects exist. Most of the algorithms used for failure detection rely on these models to detect significant changes in a flight environment. In actual practice, however, most vehicle vibration monitoring systems are corrupted by high rates of false alarms and missed detections. Research conducted at the NASA Ames Research Center has determined that a major reason for the high rates of false alarms and missed detections is the numerous sources of statistical variations that are not taken into account in the modeling assumptions. In this paper, we address one such source of variations, namely, those caused during the design and manufacturing of rotating machinery components that make up aerospace systems. We present a novel way of modeling the vibration response by including design variations via probabilistic methods. The results demonstrate initial feasibility of the method, showing great promise in developing a general methodology for designing more accurate aerospace vehicle vibration monitoring systems.
Design of a Microfactory
Authors: Mishima Nozomu , Tanikawa Tamio , Ashida Kiwamu , Maekawa Hitoshi
Published: June 2008

This paper describes the concept of a “microfactory” and design basics of its components. The microfactory is a super-miniature manufacturing system consists of miniature machine tools and manipulators. The authors proposed the concept and prototyped the first performable microfactory later in 1999. The former part of the paper introduces the basic concept and effort to systemize the factory. The concept was first proposed in 1990 and was expected to reduce energy consumption and space occupation of small parts fabrication. In 1996, the “micro-lathe” was developed and showed an unexpectedly good machining capability. The success of the micro-lathe was the driving force to systemize the rest of the microfactory. The newly prototyped microfactory was able to machine several small parts and assemble them into a miniature ball bearing to show its capability. The latter half of the paper describes design concepts, theories and tools that were used in designing the each component of the microfactory.
Deriving Function-Failure Similarity Information for Failure-Free Rotorcraft Component Design
Authors: Roberts Rory A. , Stone Robert B. , Tumer Irem Y.
Published: June 2008

Performance and safety are the top concerns of high-risk aerospace applications at NASA. Eliminating or reducing performance and safety problems can be achieved with a thorough understanding of potential failure modes in the designs that lead to these problems. The majority of techniques use prior knowledge and experience as well as Failure Modes and Effects as methods to determine potential failure modes of aircraft. During the design of aircraft, a general technique is needed to ensure that every potential failure mode is considered, while avoiding spending time on improbable failure modes. In this work, this is accomplished by mapping failure modes to specific components, which are described by their functionality. The failure modes are then linked to the basic functions that are carried within the components of the aircraft. Using this technique, designers can examine the basic functions, and select appropriate analyses to eliminate or design out the potential failure modes. This method was previously applied to a simple rotating machine test rig with basic functions that are common to a rotorcraft. In this paper, this technique is applied to the engine and power train of a rotorcraft, using failures and functions obtained from accident reports and engineering drawings.
Structured Indexing of Process Capability Data
Authors: Kern Daniel , Thornton Anna
Published: June 2008

Process capability data can aid a design through ensuring the part tolerances are achievable with the current manufacturing capability. Many companies want to store process capability data in databases to make it available to all engineers. The success of a process capability database is highly dependent on the design of its structure and a method to index data for ease of input and retrieval. In this paper, the authors describe a new method of representing characteristics of a manufactured component using the attributes of feature, geometry, material, and process. This representation enables better storage and retrieval of process capability data. In addition, the authors describe a method for rapidly and robustly indexing components’ characteristics for entry into a process capability database.
DPP: A Distributed Process Planning Approach Using Function Blocks
Authors: Wang Lihui
Published: June 2008

The objective of this research is to develop a new methodology for intelligent and distributed process planning. The primary focus of this paper is on the architecture of the new process planning approach, using function blocks as controller language. The secondary focus is on the other supporting technologies such as machining feature-based design and agent-based decision-making. The methodology proposed for distributed process planning is based on a design-for-machining concept that can seamlessly integrate feature-based design and agent-based planning into function block-based CNC control. Different from traditional methods, the proposed approach has a two-layer structure – supervisory planning and operation planning. The supervisory planning is performed in advance at shop floor level, followed by the operation planning accomplished at run-time at machine level by open CNC controllers. Through decentralization, the distributed process planning shows promise of improving system performance within today’s continually changing shop floor environment.
Modelling and Control of PKM in an Integrated Environment
Authors: Zhang Dan , Wang Lihui , Lang Sherman Y. T.
Published: June 2008

This paper introduces an integrated validation system that consists of the following modular components: kinematic/dynamic analysis module, kinetostatic model, CAD module, FEM module, CAM module, optimization module and visual environment for remote control. In this paper, authors focus mainly on the modules of kinetostatic modeling, dynamic modeling, PKM design optimization, and remote control realization. The prototype of a 3-dof PKM developed at NRC-IMTI is used as an example throughout this paper.
Automation of Linear Tolerance Charts and Extension to Statistical Tolerance Analysis
Authors: Shen Zhengshu , Shah Jami J. , Davidson Joseph K.
Published: June 2008

Manual construction of tolerance charts is a popular technique for analyzing tolerance accumulation in parts and assemblies. But this technique has some limitations: (1) it only deals with the worst-case analysis, and not statistical analysis (2) it is time-consuming and errorprone (3) it considers variations in only one direction at a time, i.e. radial or linear. This paper proposes a method to automate 1-D tolerance charting, based on the ASU GD&T global model and to add statistical tolerance analysis functionality to the charting analysis. The automation of tolerance charting involves automation of stackup loop detection, automatic application of the rules for chart construction and determination of the closed form function for statistical analysis. The automated analysis considers both dimensional and geometric tolerances defined as per the ASME Y14.5 – 1994 standard at part and assembly level. The implementation of a prototype charting analysis system is described and two case studies are presented to demonstrate the approach.
A Reconfigurable 3D Engineering Shape Search System: Part II — Database Indexing, Retrieval, and Clustering
Authors: Lou Kuiyang , Jayanti Subramaniam , Iyer Natraj , Kalyanaraman Yagnanarayanan , Prabhakar Sunil , Ramani Karthik
Published: June 2008

This paper introduces database and related techniques for a reconfigurable, intelligent 3D engineering shape search system, which retrieves similar 3D models based on their shape content. Feature vectors, which are numeric “fingerprints” of 3D models, and skeletal graphs, which are the “minimal representations of the shape content” of a 3D model, represent the shape content. The Euclidean distance of the feature vectors, as well as the distance between skeletal graphs, provides indirect measures of shape similarity between the 3D models. Critical database issues regarding 3D shape search systems are discussed: (a) database indexing, (b) semantic gap, (c) subjectivity of similarity, and (d) database clustering. An Rtree based multidimensional index is used to speed up the feature-vector based search operation, while a decision treebased approach is used for efficiently indexing/searching skeletal graphs. Interactions among users and the search system, such as relevance feedback and feature vector reconfiguration, are used to bridge the semantic gap and to customize the system for different users. Database clustering of the R-tree index is compared with that generated by a selforganizing map (SOM). Synthetic databases and real 3D model databases are employed to investigate the efficiency of the multidimensional index and the effectiveness of relevance feedback.
Machined Feature Estimation and Inspection for Internet-Based Manufacturing System
Authors: Li Yadong , Gu Peihua
Published: June 2008

With easy access of the Internet, the real-time, web-based collaborations are impacting the current practices of product design and manufacturing. In this research, an Internet-based manufacturing design system has been developed based on the collaborations of several partners located thousands of miles away from each other. This paper introduces a sub-system of this Internet-based manufacturing system for machined feature estimation and inspection using 3D solid models. Using the engineering data of cutting processes received from our collaborator, through the broadband Internet, taking into account of the factors like cutting forces and tool deflections, this sub-system determines the material removal processes by subtracting the tool cutting volume from work-piece raw material. It creates the machined 3D solid geometry models by simulating the machining processes. The estimated geometry is then taken to a simulated inspection process for engineering analysis and CNC machining program verification. To simulate the inspection process on a Coordinate Measuring Machine (CMM), a series of rays is shot to the machined surface to simulate the CMM probe touching for acquiring surface data. The simulated measurement data is then localized to design surface and comparison between them is made to quantify the machining errors. Through the Internet, the geometrical features and inspection result can be visualized and shared by other sub-systems of the whole manufacturing system based on the commercial CAD data formats. The operation of this subsystem and related facilities is local execution.
Reeb Graph Based Shape Retrieval for CAD
Authors: Bespalov Dmitriy , Regli William C. , Shokoufandeh Ali
Published: June 2008

Our recent work has described a framework for matching solid of mechanical artifacts models based on scale-space feature decomposition. In this work we adopt a method of comparing solid models based on Multiresolutional Reeb Graphs (MRG) similarity computations. This method was originally proposed by Hilaga et al. in [1]. Reeb Graph technique applies MRG structure to comparisons of approximate models found in the graphics community, such as polygonal meshes, faceted representation and Virtual Reality Modeling Language (VRML) models. First, we provide a brief review of shape matching using Multiresolutional Reeb Graphs and present an approach to matching solid models. Second, we show the performance of the Reeb Graph technique when handling primitive CAD models, such as cubes and spheres; then we perform experiments with more complex models, such as LEGO models and mechanical parts, and we discuss Reeb Graph technique’s performance on complex CAD models. Third, we emphasize several problems with the existing technique. Finally, we conclude with discussion of future work.
Configuration-Based Exploratory Design
Authors: Rathnam Tarun , Collins Michael , Paredis Christiaan J. J.
Published: June 2008

In this paper, we present a method for adapting the use of configuration systems to design exploration. Typically, the design of complex systems is realized as the integration of several constituent components. To guide the development of each of these components, designers would like to select the most promising family of solutions early in the design process. However, since the best family of solutions is the one containing the best instance, selecting the best family would require analyzing every individual instance in each family. This is a costly exercise that we are trying to avoid in the first place by focusing only on the most promising family of solutions. To overcome this catch-22, we introduce the use of automated configuration systems to conduct design exploration at a reduced cost. Such a configuration system can explore families of solutions automatically, not necessarily in full detail, but in sufficient detail to exclude the worst solution alternatives. We have adapted the traditional Propose and Revise approach to configuration into a hierarchical, modular framework that avoids the large initial investment involved in creating a traditional configuration system. We conclude this paper by illustrating our approach with an initial implementation of our framework called LEGION.
A General Approach to E-Learning Software Development
Authors: Zhang W. J. , Li Jingxin , Xie Helen , Shi Zhongzhi
Published: June 2008

With the rapid advancement of computing technology, the paradigm of learning has been changed from the classroom environment to the web environment. The support software for e-learning is key to implementing such a web-based learning paradigm. In this paper, a general approach to construct an elearning software system is proposed and described. The approach is based on an analogy between e-learning and mass customization product design. In the case of mass customization product design, customers can participate in a product design and realization process regardless of temporal and spatial restrictions. In the case of e-learning, learners can access a virtual teaching center at any time and at any place. This analogy has further led us to exploit fruitful developments in computer software for mass customization, in particular, a so called web-based configuration design system through the constraint satisfaction problem (CSP) approach. This paper discusses both conceptual development and implementation. An illustration is given for implementation.
Web-Based Self-Paced Virtual Prototyping Tutorials
Authors: Bhatt Rajankumar , Tang Chin Pei , Lee Leng-Feng , Krovi Venkat
Published: June 2008

By permitting designers to realistically, accurately and quantitatively prototype and test multiple intermediate models within virtual environment, Virtual Prototyping (VP), also known as Simulation-Based Design (SBD), has rapidly gained popularity and become a crucial part of most engineering design processes. While there is a significant demand from industry for students trained in this methodology, currently there is not much room in engineering curriculum to permit widespread adoption in the lecture-based classroom. In this paper, we describe the rationale and the stages in the development of a series of web-based and self-paced VP tutorials targeted at students of a course in machine and mechanism design. These undergraduate seniors are permitted to: (1) interactively explore the process of creating engineering analysis models in integrated VP environment; (2) develop skills for interactive SBD of models; and (3) develop their engineering judgment by interactive exploration of a spectrum of examples. The outcome of a phased introduction of these exercises and our experience based on the first successful course offering are also discussed.
Dynamic Stress Analysis of an Epicyclic Gear Pump
Authors: Baksi Stanley , Grote Karl , Harris Nasser
Published: June 2008

Both Epicyclic gear trains and reciprocating pumps have been used for years and their advantages are well documented. This paper presents a method to combine the advantages of epicyclic gear and reciprocating pump to provide a configuration for a new kind of pump called the epicyclic gear pump. Using features of IDEAS, the pump is modeled and the dynamic stress acting on the pump is calculated. Further development of the epicyclic gear pump leading to an engine similar to the rotary engine is left to future research.