bluuebunny/crossref_metadata_2025 huggingface dataset:
Kinematic Abstractions for General Manipulator Control
Authors: Kapoor Chetan , Tesar Delbert
Published: February 2021

Robot kinematics generally includes forward and inverse kinematics at the position, velocity, and acceleration level. These constructs are essential for the cartesian control of serial manipulators. This paper presents the development of a C++ class library that supports the forward and inverse kinematics of all possible geometries of serial manipulators. Object-oriented analysis and design is the primary software development methodology used. Application of this methodology led to the sub-division of the kinematics domain into forward, and inverse kinematics. Analysis of these sub-domains resulted in their further sub-division, identification of abstract components, development of classes, interface specifications, and finally implementation and testing. Examples demonstrating programming and extensibility of the components in the kinematics domain are given. This work was part of the development of the Operational Software Components for Advanced Robotics (OSCAR) at the Robotics Research Group of The University of Texas at Austin. OSCAR supports reusable software components for the control of advanced robotic manipulators. This includes mathematical constructs, kinematics, dynamics, fault-tolerance, performance criteria, manual controllers, and a variety of physical manipulators and simulations.
Feasible Contact Forces in Semi-Active Vehicles
Authors: Sreenivasan S. V. , Choi B. J.
Published: February 2021

This article provides an integrated approach for identifying the feasible contact force distribution in various classes of semi-active vehicles including (a) vehicles with and without omni-directional motion capability, (b) vehicles with varying levels of actuated, unactuated, and spring joints, and (c) vehicles in singular kinematic configurations. The emphasis is on studying systems that have some level of overactuation which is defined as the number of actuators minus the mobility of the vehicle system. It is well known in the active vehicles and biomechanics literature that such overactuation can be used to optimize contact conditions to enhance locomotion capability. Once appropriate contact forces are computed, the desired actuator efforts can then be obtained. A geometric approach based on screw theory that leads to invariant analytical results has been used.
Kinematic Clearance Sensitivity Analysis of Spatial Structures With Revolute Joints
Authors: Innocenti Carlo
Published: February 2021

The paper presents a new method to assess the influence of joint clearances in spatial structures that are composed of links connected by revolute joints. The method allows assessment of the amount by which joint clearances affect the rigid-body position of a generic link of the structure when an external load is exerted on the link. Unlike other procedures, the proposed method relies on the clearance-free idealization of the structure under investigation. An example shows application of the proposed method to the analysis of the structure derived from a multi-loop manipulator by freezing its actuators.
Applying Shape Annealing to Full-Scale Transmission Tower Re-Design
Authors: Shea Kristina , Smith Ian F. C.
Published: February 2021

Application of structural optimization to transmission tower design is facilitated since major costs, including material, transportation, construction and maintenance, are directly proportional to the mass. Transmission towers are unique civil structures since they are often free from aesthetic considerations making the results of structural optimization less susceptible to subjective assessments. In this paper, shape annealing, a computational design technique, is applied to the optimally directed re-design of transmission towers. Shape annealing has been presented previously as an effective method for the generation of conventional and innovative discrete structures. So far, the method has been targeted at the conceptual design stage. This paper focuses on the re-design of existing full-scale transmission towers in collaboration with Énergie Ouest Suisse (EOS) in Lausanne, Switzerland. The purpose of this paper is to present the challenges and results of applying shape annealing to a highly constrained industrial application as well as the modifications that were needed. This application resulted in suggestions for improving the existing design and insights about practical application of the method to create a system for transmission tower design.
Design Model Applied to the Design of Production Machines
Authors: de Roode B. H. , Crone H. A.
Published: February 2021

This paper describes a general design model that serves as a base for computer-support in the conceptual design stage. The model consists of a model of the artefact to be designed, design activities and knowledge. The artefact model contains multiple views, each highlighting a certain aspect of the design. Design activities are performed to create this model and knowledge describes information generated in the past that can be reused. The general design model has been used to develop a specific model for the design of production machines. This specific model has been implemented in a prototype computer-program and has been evaluated within several companies. The results are promising and show that designers gain new insights by using the model.
Concurrent Robust Product and Process Design
Authors: Lindkvist Lars , Söderberg Rikard
Published: February 2021

This paper presents a method for assembly evaluation. The method uses two evaluation criteria, robustness and variation analysis, and is supported by a software tool developed by the authors. The robustness evaluation aims at detecting design and assembly solutions that are sensitive to variation and may cause problems during production. Using this method in early product and process design phases helps to find more robust concepts, resulting in shorter production start-up time and better precision.

The method’s use is exemplified in a concept study of the assembly process of the door to the body of a (fictitious) jeep. The study shows that the proposed method can be used to obtain an objective comparison between different concepts. This comparison includes both general robustness and the expected variation in the critical dimensions. The results can be used, together with economical and practical aspects, to determine which concept is best suited for the assembly process.

The software used is implemented in the MS Windows environment and has an JGES interface that enables the user to import CAD geometry from an arbitrary CAD system. It can perform different types of robustness evaluations as well as traditional variation analyses.
Locating Scheme Analysis for Robust Assembly and Fixture Design
Authors: Söderberg Rikard , Carlson Johan S.
Published: February 2021

This paper highlights the importance of robust locating scheme design and proposes methods and tools for components and assembly robustness design and evaluation.

The way datums and locators affect the entire variation control process, from early design stages to inspection of the final product, is discussed, and a structured work plan for incorporating robust locating scheme design into embodiment design is proposed.

Methods and tools for locating scheme analysis are developed and presented Sensitivity analysis and variation analysis are exemplified and discussed using a small assembly case. A comparision of Monte Carlo simulation versus the “matrix method” is made for variation analysis.
Shape Optimization for Fatigue Problems Using Continuum Damage Mechanics
Authors: Schnack Eckart , Weikl Wolfgang
Published: February 2021

In mechanical engineering we are usually concerned with dynamically loaded constructions, i.e. machinery parts. In this paper a new idea for high-cycle fatigue behaviour working with the two-grid method is presented, using one grid on the micro-level and the other one for the meso-level. While on the meso-level the behaviour of the construction in high-cycle fatigue is nearly linear, however on the micro-level there are defects and microcracking with small plastic zones around the crack tips. Using a homogenization technique, we develop an energy release rate formulation on the micro-grid, from which the evolution equation for increasing damage arises. The new idea is now to define the damage at the meso-level depending on the damage at the micro-level, while controlling the stress redistribution by a modified locally coupled analysis. This leads to a new concept for shape optimization of mechanical engineering problems using the sequential quadratic programming technique.

The theoretical and numerical results are controlled by experiments using a hydropulser machine. For high quality steel an increase of lifetime by a factor of about 3 was achieved for our shape optimized notched structures compared with the ones possessing classical circular cut-outs. Therefore we can say that this concept offers a new possibility for lifetime increasement of mechanical engineering structures.
General Procedure for Parametrisation With 3D-CAD Systems
Authors: Vajna Sándor , Schabacker Michael , Schmidt Rajko
Published: February 2021

Modern 3D CAD systems offer a series. of new possibilities in product development [Babel, 1997]. However, these technologies are not always utilised in their whole range like, for example, parametric modelling. The functionalities for the parametrisation of geometries are particularly profitable for the establishing of families-of-parts. They enable the development of design variations with low expense. In this paper, procedures for a methodical and systematic parametrisation are presented which were successfully applied in industrial projects using various CAD systems. Conclusions for requirements on parametric CAD systems were drawn from experiences gained during these projects.
A Systemic Decision Approach for Capitalizing Dysfunctions in Design Processes
Authors: Cardinal Julie Stal-Le , Mekhilef Mounib , Bocquet Jean-Claude
Published: February 2021

Considering that general industrial objectives are still optimization of cost, delay, and quality, we present a dysfunctions approach for the decision making processes.

In this paper, we introduce the concept of Decision Time Line which covers the decision process from the request to the answer. We highlight that it is possible to give, on the one hand, a temporal description of dysfunctions and, on the other hand, an ontological description which allows a classification of these dysfunctions. A related software tool is then able to give premature alert for an actor when he is going to make an hazardous action. A set of examples coming from industrial dysfunctions are also reported and analyzed.
On Interpreting Key Characteristics
Authors: Srinivasan Vijay
Published: February 2021

This paper examines various interpretations of key characteristics. Starting with Juran’s dictum of focusing on “vital few” and not on “trivial many”, it looks at a representative sample of extant definitions and examples. Causality and sensitivity are then discussed at some length. It is argued that it is the weighted sensitivities that determine what characteristics are key and that literature on design of experiments has supported this view all along. Finally, a statistical interpretation of key characteristics is offered as a unifying framework to capture many of the recent interpretations of key characteristics.
Benchmarking of CMM Form-Fitting Algorithms for Functional Tolerance Analysis
Authors: Meng Joe , Zhang Chun (Chuck) , Wang H.-P. Ben , Xiao Yunkui
Published: February 2021

As the most commonly used computer aided inspection device in precision manufacturing, coordinate measuring machines (CMM’s) have drawn extensive interests from both researchers and practitioners. Different form-fitting algorithms have been developed to process the sampling data gathered by CMM’s. The two most commonly used form-fitting algorithms, the least squares (LS) and the minimum zone (MZ), have caused a lot of controversies in their applications for evaluations of part tolerances and functions. One of the key issues in CMM applications is to study the effectiveness of the algorithms on part functions and what result will be incurred if an inappropriate algorithm is applied. Through a case study, this paper focuses on benchmarking of the least squares and the minimum zone algorithms for functional tolerance analysis. Comparisons are also conducted to study the Type I and Type II errors which could be caused by applying the least squares and the minimum zone algorithms, respectively. The final result shows that the minimum zone algorithm is better than the least squares algorithm.
Tolerance Design: An Axiomatic Perspective
Authors: El-Haik Basem , Yang Kai
Published: February 2021

A mathematical relationship between tolerance design and axiomatic design is derived in this paper. The approach presented here is used to optimize the settings of design parameters tolerances through non-linear programming formulations. The main theme behind these formulations is to set the individual tolerances of design parameters to achieve minimal quality loss cost subject to functional requirements independence. The programming presented here achieves both functional requirements independence per Suh’s Axiom I and assure robustness by minimizing Taguchi’s quality loss function. All the mathematical linkages were developed as it relates to our axiomatic-tolerance optimization perspective.
Incorporating the Voice of the Customer in Preliminary Component Design
Authors: Beiter Kurt A. , Ishii Kosuke
Published: February 2021

This paper describes a procedure for incorporating the voice of the customer into preliminary component design. The procedure begins with establishing the customer requirements, the engineering metrics, and their relation to the top-level subassemblies. Then, the approach establishes the component-level requirements through systematic engineering flow-down from the system level. Component-level manufacturing and operational performance models establish the link between independent decision variables and the component requirements. Thus a link is made between system level customer requirements and component parameter design. The paper uses the redesign of a computer video projector as an example.
Concurrent Design and Manufacturing for Mechanical Systems
Authors: Chang Kuang-Hua , Silva Javier , Bryant Ira
Published: February 2021

Conventional product development process employs a design-build-break philosophy. The sequentially executed product development process often results in a prolonged lead-time and an elevated product cost. The proposed concurrent design and manufacturing (CDM) process employs physics-based computational methods together with computer graphics technique for product design. This proposed approach employs Virtual Prototyping (VP) technology to support a cross-functional team analyzing product performance, reliability, and manufacturing cost early in the product development stage; and conducting quantitative trade-off for design decision making. Physical prototypes of the product design are then produced using Rapid Prototyping (RP) technique primarily for design verification purposes. The proposed CDM approach holds potential for shortening the overall product development cycle, improving product quality, and reducing product cost. A software tool environment that supports CDM for mechanical systems is being built at the Concurrent Design and Manufacturing Research Laboratory (http://cdm.ou.edu) at the University of Oklahoma. A snap shot of the environment is illustrated using a two-stroke engine example. This paper presents three unique concepts and methods for product development: (i) bringing product performance, quality, and manufacturing cost together in early design stage for design considerations, (ii) supporting design decision-making through a quantitative approach, and (iii) incorporating rapid prototyping for design verification through physical prototypes.
Error Measures for Functional Product Testing
Authors: Cho Uichung , Wood Kristin L. , Crawford Richard H.
Published: February 2021

During product development, testing of models and prototypes offers significant advantages over direct product testing, including easier, cheaper, and faster fabrication. However, two issues prevent effective functional testing with prototypes: prediction accuracy and confidence in scale testing results.

The traditional similarity method, which is based on dimensional analysis, is commonly applied to perform scale testing. However, the method may not provide accurate scale testing results, especially when available model materials are different from the final product materials. The authors have developed a new empirical similarity method, wherein specimen pairs and partial knowledge of systems are systematically utilized, to improve the prediction accuracy. In this paper we describe the construction of error measures to utilize scale testing results with confidence.

In practice, scale testing results are validated based on experiences with previous testing results. This approach to predicting accuracy is difficult to formalize. We develop and simulate a systematic two-level error estimation procedure. Realistic numerical examples demonstrate the feasibility of the approach.
On the Hybrid Workpiece Localization/Inspection/Machinability Problem
Authors: Chu Y. X. , Cao K. , Wu H. , Li Z. X.
Published: February 2021

This work addresses the localization, inspection and machinability problem of a workpiece. It includes the problem of aligning the CAD model of a workpiece such that all points measured on the finished surfaces of the workpiece match closely to corresponding surfaces on the model with minimum zone tolerances while all unmachined surfaces lie outside the model and have the maximal machinable volume. This is referred to as the hybrid localization/inspection/machinability problem and has important applications in setting up and inspecting of partially finished workpieces. This paper first gives a formulation of the hybrid problem using differential geometric theory and the minimax method, then proposes a methodology for treating localization, on-line inspection and machinability of workpieces simultaneously. The hybrid problem is decoupled into a (symmetric) localization/inspection problem and a machinability problem using the geometric properties of the hybrid problem. Then both problems are formulated as constrained optimization problems and transformed into linear programming (LP) problems to solve them easily. Finally we present simulation results to demonstrate efficiency of our method for the hybrid problem.
Strategies to Minimize Deburring Costs
Authors: Hassamontr Jaramporn , Dornfeld David A.
Published: February 2021

A number of researchers have investigated burr formation mechanisms through careful observations and well thought-out experiments. The results of their studies help untangle underlying effects of key machining parameters on burr formation. However, so far, nobody has practically incorporated such knowledge into the area of process planning. The purpose of this paper is to develop general strategies to minimize deburring cost. Furthermore, it establishes basic decision making tools for efficient deburring planning.
Reliability Analysis of Non-Constant-Size Part Populations in Design for Remanufacture
Authors: Jiang Z. H. , Shu L. H. , Benhabib B.
Published: February 2021

Remanufacture offers significant economic and ecological advantages over other end-of-life options. The goal of this research is to enable estimation of cost due to replacement of parts in systems undergoing remanufacture.

In our previous work, a novel repairable-system reliability model that allows system modifications was developed to describe a population of systems undergoing remanufacture. In this paper, the reliability model is modified to accommodate population size changes during the replacement process. The effects of two types of disturbances to population size, pulse and continuous, on the replacement rate behavior are studied. Analysis of actual industrial data is presented as an example of population replacement under continuous disturbance. This example confirms that a simulation using the reliability model proposed in this paper yields an estimation for replacement rate with acceptable error bound.
Product and Factory Modeling for Production Rate Determination
Authors: Karthik S. G. , Magrab Edward B.
Published: February 2021

An intelligent graphical user interface that captures a product’s functional and assembly structure and the factory that will make it are described. The results are then used to evaluate a factory’s production rate for the product. The program requires the product to be either a functionally uncoupled or decoupled design. The interface then: (1) implements a visualization of the functionally decomposed product structure; (2) implements an abstraction of a factory; (3) automatically generates candidate primary manufacturing processes and materials that are compatible with each other based on a very small number of attributes; (4) enables the user to make Make/Buy decisions for the components comprising the product; (5) assists the user in the selection of secondary manufacturing processes that are compatible with the primary manufacturing processes and materials for parts made in-house, and specify the vendor and the supply lead time for outsourced parts; (6) enables the specification of alternate materials and manufacturing processes; (7) implements a visual representation of the assembly structure as specified by the user; and (8) partially automates the creation of the assembly structure, and assists in the selection of assembly methods that are compatible with the materials chosen. In addition, the program assists in the design for assembly by: (1) requiring the product development team to think about the assembly process early in the design stage; (2) providing a visualization of the relationship of all components comprising the product to its other components; (3) requiring the specification of the order in which they are to be assembled; and (4) requiring the selection of assembly processes that are compatible with each other and the materials chosen. It also requires the specification of the capabilities of the factory that is going to make one or more of the components of the product, and requires that Make/Buy decisions for the parts comprising the product be made.
Advanced Failure Modes and Effects Analysis of Complex Processes
Authors: Kmenta Steven , Fitch Peder , Ishii Kosuke
Published: February 2021

This paper presents the use of Advanced Failure Modes and Effects Analysis (AFMEA) as a methodology to analyze manufacturing process reliability. The proposed method applies to early process design and seeks to improve product quality, process efficiency, and time to market. The method uses behavior modeling to relate process functions, performance state variables, and physical entities. The model can be used to define process failures explicitly and provides a framework for assessing causes and effects. An example of a precision turning operation illustrates how AFMEA applies to the analysis of manufacturing processes. A pilot analysis of an ultrasonic inspection process revealed that AFMEA is comprehensive and adaptable to other processes. Ongoing work for AFMEA is developing deployment strategies for minimal time burden and links to embedded error proofing.
Web-Enabled Feature-Based Modeling in a Distributed Design Environment
Authors: Lee Jae Yeol , Kim Hyun , Han Sung-Bae
Published: February 2021

Network and Internet technology open up another domain for building future CAD/CAM environments. The environment will be global, network-centric, and spatially distributed. In this paper, we present Web-enabled feature-based modeling in a distributed design environment. The presented approach combines the current feature-based modeling technique with distributed computing and communication technology for supporting product modeling and collaborative design activities over the network. The approach is implemented in a client/server architecture, in which Web-enabled feature modeling clients, neutral feature model server, and other applications communicate with one another via a standard communication protocol. The paper discusses how the neutral feature model supports multiple views and maintains naming consistency between geometric entities of the server and clients as the user edits the part in a client. Moreover, it explains how to minimize the network delay between the server and client according to dynamic feature modeling operations.
Conceptual Design for Assembly
Authors: Lombeyda Santiago V. , Regli William C.
Published: February 2021

This paper presents an approach to support computer-aided conceptual design of mechatronic assemblies in a collaborative, multi-user environment. We describe a system, Conceptual Understanding and Prototyping (CUP), that allows a team of design engineers, collaborating over the Internet, to develop a high-level structure-function-behavior (S-B-F) description of an assembly in a VRML-based virtual environment. Our goal is to enable users to navigate intricate product data management (PDM) and case-based design knowledge-bases, providing the ability to perform design at conceptual level and have intelligent CAD tools that can draw on details from large repositories of previously archived designs.

This work furthers research efforts in computer support for collaborative design activities — drawing on work in Human-Computer Interaction (HCI) and Computer Supported Collaborative Work (CSCW). We envision CUP to be a network interface to next-generation of engineering PDM systems and CAD databases. We are deploying CUP as query interface to the National Design Repository (http://repos.mcs.drexel.edu). This will enable CAD users to interrogate large quantities of legacy data and identify artifacts with structural and functional similarities — allowing designers to perform case-based and variant design.
The Open Assembly Design Environment: An Architecture for Design Agent Interoperability
Authors: Lyons Kevin , Shooter Steven , Keirouz Walid , Hart Peter
Published: February 2021

The Open Assembly Design Environment (OpenADE) project is an initiative at the National Institute of Standards and Technology (NIST) to provide an integrated and augmented CAD environment for assembly design. The goals of the project are: (1) to identify representations and issues for the next generation of assembly-related standards and (2) assist designers with assembly considerations throughout the phases of a product’s design — from conception to final process plan development. OpenADE’s open architecture provides standard interfaces that allow it to link to commercial and non-commercial design tools: parametric design systems, virtual reality environments, assembly analysis tools, and assembly process planners. The OpenADE project has explored issues relating to knowledge representations, virtual reality, assembly-level tolerances, constraint-based specifications, and assembly process management. This article describes the OpenADE architecture and the components that have already been implemented. It also describes plans for extending OpenADE’s assembly knowledge representations and handling of geometric and kinematic constraints.
Augmenting Conceptual Design With Manufacturing: An Integrated Generic Task Approach
Authors: Martinez Iliana , Lukibanov Oleg , Lenz Timothy , Radcliffe Clark , Sticklen Jon
Published: February 2021

The consideration of manufacturing expertise can improve both the quality and the speed of artifact design by helping to evaluate the ease with which an artifact can be manufactured. Most work in this area has addressed the detailed stage of the design process and has required precise CAD-like representations. To make the most effective use of this expertise, however, design for efficacious manufacturing should also be a concern in the conceptual stage of the design process. This paper describes a computational approach that generates conceptual fabrication plans given a qualitative description of a design. This system contains expert-level knowledge from the composites manufacturing community and incorporates a comprehensive ontology into a framework for representing conceptual manufacturing plans. The Generic Task approach serves as the broad methodological foundation for these developments. Polymer composite structural elements of an unmanned aerial vehicle (UAV) are used to test this conceptual fabrication planning system.
Optimal Pose Selection for In-Situ Fabrication of Planar Mechanisms
Authors: Rajagopalan Sanjay , Cutkosky Mark R.
Published: February 2021

Solid Freeform Fabrication (SFF) techniques allow the in-situ fabrication of fully-assembled devices with mating/fitting parts. Recently, this technique of fabrication has been found to be useful for building integrated mechanisms in robotics, and a wide array of other similar applications are anticipated. An interesting issue that arises during the fabrication of such mechanisms is the determination of an optimal pose in which the mechanism should be built. For example, should the mechanism be built in a folded or stretched-out position? In conventional manufacturing these issues do not arise, as each individual link is typically manufactured separately and then the pieces are brought together during assembly.

In this paper, we address the issue of finding a preferred (or optimal) pose for in-situ fabrication of planar mechanisms. There are many factors (e.g. achievable tolerances, non-interference, workspace size limitations, thermal considerations etc.) which can determine the suitability of a candidate build pose so that pre-specified task requirements are met. We limit our analysis to finding the optimal build configuration given achievable (in general, non-homogeneous, anisotropic) accuracy on joint position. For this treatment, we also make the simplifying assumption that the task requirements can be best satisfied by minimizing variability of link-lengths. Alternate task requirements, for example, maintaining end-point accuracy within a tolerance region, are being considered as part of ongoing work. We cast the problem of minimizing variability in link length as that of determining the relative position of two location tolerance regions for which the difference between their extremal distances is at a minimum (i.e., as they undergo constrained relative motion in the Euclidean plane). The method is similar to computational geometry techniques that have been developed in pattern matching and robot motion planning, with some important differences. We present some example mechanisms and their optimal pose under given workspace configurations.
Risk Effect Minimization Using Flexible Product and Process Design
Authors: Roser Christoph , Kazmer David
Published: February 2021

This paper addresses robust product development practices by evaluating the flexibility of the development process and the resulting product and process designs. A flexible design has the ability to change performance while requiring only minor time and costs to change the design parameters. A design change might be necessary if the actual design performance is not matched by the predicted design performance. The described methodology utilizes response surfaces for multiple performance attributes to assess the utility across the design space. This utility is optimized with respect to the robustness against noise and prediction inaccuracies. Based on this design, non-dominant pareto optimal sets of all feasible design changes are then developed to asses potential performance gains against the time and cost needed to incur the change assuming correct performance predictions. While robust design practices seek to reduce the risk of design change, the proposed method rather accepts the risk of design change and minimizes the potential negative effects.
Selective Disassembly of Components With Geometric Constraints
Authors: Srinivasan Hari , Gadh Rajit
Published: February 2021

This paper analyzes the problem of global disassembly of a selected component from a geometrically constrained assembly. The geometric constraints are (I) spatial constraints due to the three-dimensional geometric interactions between the components in an assembly and (II) user-defined constraints, such as grouping of components as subassemblies and directional constraints on component geometry. A new algorithm has been proposed to determine the disassembly sequence for a selected component, minimizing the number of component removals. The algorithm analyzes both the spatial constraints of the assembly geometry and the user-defined constraints in evaluating the accessibility of components, which is followed by determining the topological disassembly ordering of the components to evaluate an optimal sequence. Preliminary implementation results of the algorithm, and discussions on the applicability of the algorithm to maintenance, recycling and assembling applications, are presented.
Automated 3D Fixture Layout Design
Authors: Wang Michael Yu
Published: February 2021

This paper presents a new approach to the problem of fixture layout design for 3D workpieces. The approach is based on a concept of optimum experiment design, and the problem is treated as an optimal pursuit to select optimal locators from an initial collection of a large number of fixel locations on the surfaces of the given workpiece and to achieve form-closure for the part. An interchange algorithm is described, in which the fixture locators are generated sequentially first and are further improved. The algorithm uses the D-optimality criterion to minimize the workpiece positioning error. An example of a 3D workpiece is presented to illustrate the effectiveness of the proposed approach.
Introducing Knowledge-Based Engineering Into an Interconnected Product Development Process
Authors: Whitney Daniel E. , Dong Qi , Judson Jared , Mascoli Gregory
Published: February 2021

Recently, a large automobile company implemented a Knowledge-based Engineering (KBE) application to help design an engine component. While the KBE developers aimed to facilitate a single engineer’s ability to design this component using only the KBE application, it can be shown that in fact this component’s design is tightly coupled to that of several others. Can KBE handle situations like this? How common are they? To address these and other questions, Design Structure Matrix (DSM) models were made of this component at three levels: system interactions, assembly of the component, and individual parts. The size, row names, and internal entries of these matrices were compared to matrices constructed from several conventional written design guides and a flowchart of the KBE application. In each case, the DSM contained more rows or more matrix entries per row, especially at the system interaction level. Since the DSMs were constructed by interviewing experienced engineers, one implication is that while low-aggregation information may be documented, system level information at this company mostly resides in people’s heads. An informal measure of “knowledge content” based on the number of matrix entries per row was shown to be consistent with similar measurements made on DSMs obtained by several other researchers. These results indicate some of the scope and complexity challenges that KBE faces.
Supporting Product Introduction Processes Through Product Structures
Authors: Trott Steven J. , Baxter James E. , McKay Alison , de Pennington Alan , Henson Brian
Published: February 2021

This paper reports research on approaches for accessing and controlling product data within the Product Introduction Process (PIP) through the specification, prototyping, and integration of a set of product structures, product viewpoints and their relationships. A significant achievement has been the validation of a collection of computer-based models of product structures that enable the capture of work breakdown, product specification, product functionality, and the physical parts that comprise the product. Furthermore, a number of relationships between these product structures and the business processes that use and create them have been identified. The work presented in this paper demonstrates the importance of representing relationships between product introduction processes and products through the adoption of product structures. The potential for exploiting product structures to improve understanding of relationships between products and processes is illustrated. A case study captures flows of related functional and physical product structures within PIPs across a two-tier supply chain, and discusses the issues involved in supporting such related product and process information.
Comparison-Based Decision Making in Engineering Design
Authors: Wan Jie , Krishnamurty Sundar
Published: February 2021

Engineering design has been increasingly viewed as a decision making process involving complex multiple criteria optimization. Many Multi-Attribute Utility Theory (MAUT)-based models exist to develop the single attribute functions and the weight assessment for the overall utility with individual strengths and drawbacks. Focusing on the efforts towards a consistent preference representation supported engineering design procedure, a binary comparison and indirect assessment based method is presented in this paper to efficiently aid the continuous multicriteria decision making in engineering design. Uniqueness of this approach lies in its ability to deal with issues such as the preference consistency and accuracy, decision maker’s cognitive burden, conditions of uncertainty and risk, dynamic and interactive modeling of the designer’s preference structure, and MAU-like aggregation of the system utilities. The many salient features of this comparison-based multiattribute utility approach include a novel inequality lottery strategy, an adaptive meshing based linear additive utility model, a linear programming based dynamic preference modeling and systematic consistency checking, and an efficient exploration of optimal solution set and sensitivity analysis. The development of this method and its utilization in engineering design are presented in the context of a mechanism parametric design problem and the results are discussed.
Decision Support for Systematic Product Evolution
Authors: Coulter Stewart , Bras Bert
Published: February 2021

Many companies are trying to reduce the environmental impacts of their products. Simultaneously, designers are forced to achieve the same, or more stringent, design constraints in less time, balancing the need to get a product out the door with the desire to improve the product’s performance. It is our contention that a systematic approach to designing a product over several revisions, creating a systematic, evolution of a given product, will facilitate achievement of environmental goals within the constraints of the design process for this product. In this paper, we outline a method, and associated decision support for developing such a systematic multi-iterational design strategy. The approach is illustrated with a design of an automotive center console for reduced environmental impact while minimizing the cumulative amount of resources spent over multiple product iterations.
Agency in Concurrent Engineering
Authors: Birmingham William P. , D’Ambrosio Joseph G.
Published: February 2021

We have developed a formal process for concurrent engineering that maximizes concurrency in the CE enterprise through decentralized, distributed decision making, and optimizes across the CE enterprise by (minimally) coordinating design and manufacturing decisions by enforcing feasibility and preferential dependencies. We call this process hierarchical concurrent engineering (HCE). A central idea in this work is decentralization (and concomitant distribution), where we attempt to minimally control the actions (decision making) of engineers. The HCE decision-making model is a way of describing the network of decision processes needed for a CE enterprise. This model extends traditional “influence diagrams” as it incorporates constraints and multiple decision makers. We also present a software agent architecture that implements the HCE decision model, and we show how this model naturally leads to design processes, which are sequences of coordinated decisions.
The Role of Shape in Communicating Designers’ Aesthetic Intents
Authors: van Breemen Ernest J. J. , Sudijono Slamet
Published: February 2021

Product designers want to evoke specific target customer responses. They communicate their aesthetic intents to target customers by means of the shape, composition and physical properties of the designed product. As a contribution in the development of a computer aided conceptual support system, we developed a theory of communication of aesthetic intents, with a formalism of a mapping between the space of shape characteristics and the space of aesthetic characteristics, describing how aesthetic intents can be related to the shape of a product. We used this as a starting point for empirical studies into respondents shape perception of products, and their appreciation of these products. We analyzed the results of these experiments and concluded that a first version of the mapping can be established.
CFMA: An Effective FMEA Tool for Analysis and Selection of the Concept for a New Product
Authors: Hari Amihud , Weiss Menachem P.
Published: February 2021

It has been established and widely accepted that the early phases of the engineering design process are the most critical to the technical and economical success of a new product. Most of the product’s performance and failures are determined and more than 75% of its life cycle cost is committed during the conceptual design phase. A major step in all conceptual design methodologies is the concept selection phase, where out of the many concepts generated, one is selected and it becomes the basis for the favored solution. Such a selection must be influenced by the potential failure modes, that the product, which is based on the chosen concept, may suffer from and will be exposed to in the future. In the past, the well established Failure Mode and Effects Analysis - FMEA was used for this purpose, but in the system level only. The proposed, new Conceptual Failure Mode Analysis - CFMA is a modified version of FMEA, that was developed for use in the conceptual design phase of a new product. CFMA enables to select the preferred concept (out of many generated), based also on future potential failure modes. CFMA is considered by the authors, as a major and important attribute in concept selection, that can now be taken into account in new concepts evaluation. CFMA is also shown as a vital part of the prescriptive Integrated, Customer Driven, Conceptual Design Method - ICDM, that has recently been introduced by the authors. It is the aim of this paper to introduce CFMA as a substantial additional tool for concept selection.
Identifying Product Portfolio Architecture Modularity Using Function and Variety Heuristics
Authors: Zamirowski Erik J. , Otto Kevin N.
Published: February 2021

This paper proposes a method for identifying product portfolio architecture alternatives based upon customer needs and product function. Customer needs and uses are interpreted according to the variation in performance target values across the market and within the set of individual customer uses. Product uses are represented by function structures consisting of the functions necessary for achieving the use. These individual product use function structures are combined into a monolithic function structure to represent the entire product portfolio. This monolith is then partitioned according to function and product variety heuristics into function clusters that anticipate product modules. This candidate modularity can then be used to deliver product variety across the product portfolio given functional constraints. A portfolio of xerographic products is used as the working example.
Product Platform Design: A Graph Grammar Approach
Authors: Siddique Zahed , Rosen David W.
Published: February 2021

The current marketplace can be characterized by the need for variety, faster time to market, and decrease in cost. To survive companies are shifting from a mass production mode to mass customization to provide the necessary variety. One of the key elements of mass customization is the product platform. In this paper we will investigate the use of graph grammars to develop common platforms for a set of similar products and to specify the product portfolio supported by the platform. To facilitate development of common platforms a formal product family architecture representation is presented which separates the core and the options to facilitate the identification of the common platform. Graphs are used to represent the core for function and structure viewpoints, and grammars to specify the relationships among the core and the options. Arguments on suitability of graph grammars in common platform development, are also presented in the paper.
Set-Based Models of Product Platform Design and Manufacturing Processes
Authors: Finch William W.
Published: February 2021

This paper describes an empirical test of the expressive capacity of set-based causal models representing design and manufacturing processes for product platforms. First, the paper gives a brief overview of set-based modeling techniques developed in earlier work. It describes the underlying assumptions of set-based causal models and defines elements of the tables and graphs that represent them. The paper then presents tabular and graphical representations of greatly simplified design or manufacturing processes for three varied industrial products: Sony Walkman personal stereos, the Xerox Document Center family, and Denso automotive panel meters. A short discussion follows each example and examines issues raised by the construction of each model. This empirical work supports development of methodology for constructing set-based models of general product development processes.
Development of a Functional Basis for Design
Authors: Stone Robert B. , Wood Kristin L.
Published: February 2021

Functional models represent a form independent blueprint of a product. As with any blueprint or schematic, a consistent language or coding system is required to ensure others can read it. This paper introduces such a design language, called a functional basis, where product function is characterized in a verb-object (function-flow) format. The set of functions and flows is intended to comprehensively describe the mechanical design space. Clear definitions are provided for each function and flow. The functional basis is compared to previous functional representations and is shown to subsume these attempts as well as offer a more consistent classification scheme. An example is provided for using the functional basis to form a functional model. Applications to the areas of product architecture development, function structure generation, and design information archival and transmittal are discussed.
The “Generation Gap”: A CSP Approach Linking Function to Form Grammar Generation
Authors: Schmidt Linda C. , Shi Hai , Kerkar Sameer
Published: February 2021

The authors use a Constraint Satisfaction Problem (CSP) approach to the assembly problem linking a function-based design generation algorithm to a geometric modeler. The goal is to create a unified graph-grammar based design generation tool that enables generation of geometrically valid designs from a functionally valid design concept. The paper demonstrates the Assembler, a graph-grammar based algorithm that takes a functionally valid but geometrically ambiguous design of a cart made of Meccano Erector Set components and converts it into valid solid models of cart designs. The authors show that the approach has potential but that even the simple cart example requires more sophisticated constraining than was done in this implementation.