bluuebunny/crossref_metadata_2025_split huggingface dataset:
Forming Product Design Specifications
Authors: Otto Kevin N. 
Published: February 2021

Abstract
Design teams commonly form quantitative functional specification lists that define performance targets for a product. Meeting these specifications ensures that the customer needs are satisfied. A central difficulty is to identify the relevant metrics to use as specifications. A working methodology is presented here to establish relevant, quantitative, measurable performance specifications. To start, customer needs, their importances, and the customer use patterns are gathered for the product. Voice-of-the-customer methods are augmented to distinguish no-compromise constraints that must be met. Next, a design is analyzed to establish a representative function structure, applying Pahl and Beitz’s systematic design approach. An optimal function structure can now be defined by a condition of simultaneous maximum simplicity and comprehensive coverage of the gathered customer needs. The function structure can then be used as a list over which specifications are to be made, with at least one specification per sub-function. Having a rational function structure allows a team to more easily determine variables on which to make specifications. A team can then use the House of Quality to document and form consensus over these specifications in the typical way.
Student Responses to Impromptu Estimation Questions
Authors: Linder Benjamin , Flowers Woodie 
Published: February 2021

Abstract
Undergraduate students were asked to give rough estimates for basic engineering quantities associated with common engineering artifacts. Their responses to two such estimation questions are presented and discussed. Examples are drawn from the responses to illustrate the extreme difficulty students had performing estimates and using engineering fundamentals in impromptu situations. We propose a shift from engineering pedagogy’s focus on detailed analysis to a focus on estimation to improve students’ overall problem-solving skills.
A Reverse Engineering and Redesign Methodology for Product Evolution
Authors: Otto Kevin N. , Wood Kristin L. 
Published: February 2021

Abstract
New products drive business. To remain competitive, industry is continually searching for new methods to evolve their products. To address this need, we introduce a new reverse engineering and redesign methodology. Motivation is provided by the S-curve product improvement history. We start by formulating the customer needs, followed by reverse engineering, creating a functional model through teardowns. The functional model leads to specifications that match the customer needs. Depending upon required redesign scope, new features are possibly conceived, or not. Next models of the specifications are developed and optimized. The new product form is then built and further optimized using designed experiments. An electric wok redesign provides an illustration. The methodology has had a positive impact in results and systematic approach, both on design education and application.
Formalisms for Negotiation in Engineering Design
Authors: Scott Michael J. , Antonsson Erik K. 
Published: February 2021

Abstract
Engineering projects often undergo several design iterations before being completed. Information received from other groups working on a project (analysis, manufacturing, marketing, sales) will often necessitate changes in a design. The interaction between different groups associated with a design project often takes the form of informal “negotiation.” This form of interaction commonly arises when engineering information is imprecise. The Method of Imprecision (MOI) is a formal method for the representation and manipulation of preliminary and imprecise design information. It provides a mechanism for the formalization of these informal negotiations. The nature and scope of informal negotiation in engineering is explored and discussed, and application of the MOI is illustrated with an example.
On the Nature and Consequences of Functional Couplings in Axiomatic Machine Design
Authors: Johannesson Hans L. 
Published: February 2021

Abstract
A functional coupling is defined in this work as a harmful interaction between two sub-systems, components or parts on the same hierarchical level within a product structure. In order to qualify as a functional coupling this interaction must be such that the choice of one sub-system, component or part solution decreases the possibility to fulfil the requirements governing another solution. In this work the nature and characteristics of such functional couplings are analysed and the following consequences when judging the degree of functional coupling in a product are discussed.
In particular this work identifies and classifies the information needed to characterize and judge functional couplings in structural axiomatic machine design. The information needed for coupling removal decisions is identified. This is very important as it increases the robustness of a design. Furthermore, the difficulty with limited information on higher hirarchical product structure levels is discussed and an iterative strategy to deal with this problem is suggested.
Dependence of Early Engineering Concepts on Information Characteristics
Authors: Knoop Willem G. , van Breemen Ernest J. J. , Vergeest Joris S. M. , Wiegers Tjamme 
Published: February 2021

Abstract
The expectations of computer tools to support the conceptual design phase are not yet met. An experimental approach to discover the use of information in conceptual design will give a realistic insight of the information requirements. This can be used to specify future computer support systems. A method to observe the use of information in a conceptual design process has recently been developed. The method has been tested and fine-tuned through the observation of 10 design sessions. Valuable empirical data resides from this experiment. Data has been analyzed in several perspectives. This paper presents the results of the activity/information analysis of the experiment in relation with the quality of the design concept. For the latter a rating system has been defined to quantify this. We have found a significant positive correlation of the amount of information that is communicated and the quality of the design. Furthermore a discussion is given on the relation between information and the activities of the designer. Analysis activities are more communication intensive compared to synthesis and evaluation tasks.
Required and Requested Information During Conceptual Engineering Design As Found by Categorization of Empirical Data
Authors: Wiegers Tjamme , Van Breemen Ernest J. J. , Knoop Willem G. , Vergeest Joris S. M. 
Published: February 2021

Abstract
To offer effective computer support in the early stages of the engineering process, we need more insight in the information needs of the designer during these stages. For this reason we developed a new method to observe the information handling of a designer, without forcing him or her to think aloud. We applied this method in ten sessions in which a subject had to perform a design assignment. We compared the information actually requested by the subjects, with the set of information that would be generally required according to an independent expert designer. Individual subjects differed much in the engineering aspects about which they requested information. Only 10% of the engineering aspects was requested by seven or more of them. The number of requested aspects corresponds well with the extent to which their concepts meet the requirements. We present a detailed picture of these differences and discuss possible explanations. An independently measured variable in the experiment was the designer’s performance in terms of the requirements met by the resulting design objects. We found a significant positive effect of the amount of different requested engineering aspects on this performance. The interpretation of this finding and its implications will be discussed.
Enabling Concurrent Engineering Through Collaborative Product and Process Data Management
Authors: Chen Yuh-Min , Ho Cheng-Ter , Hsiao Yun-Tau 
Published: February 2021

Abstract
This paper presents a collaborative data management framework which is capable of supporting information sharing and team data management in concurrent team-oriented product and process development by providing functions for project configuration, personal product and process item management, and team library management. Establishing this framework involves: (i) identification of functional requirements for computer-aided engineering data management through the investigation of concurrent product delivery process, with an emphasis on product and process development, (ii) use of system engineering and object-oriented modeling techniques for development of the proposed framework.
Architectures of Concurrent Engineering System for Composites
Authors: Zhang Jian , Hahn H. Thomas 
Published: February 2021

Abstract
The demand for the better quality products with shorter lead-time and lower life-cycle cost forces the manufacturing enterprises all around the world to optimize their production strategies from both enterprise engineering and enterprise operation respectively. This paper addresses the architectural issue of applying the Concurrent Engineering (CE) approach in the composite manufacturing area. It first discussed briefly the characteristics of composite manufacturing process to examine the feasibility and possibility of applying the CE approach to improve its process productivity and product quality. Then the functional requirements for a concurrent engineering system for composites (CESC) were defined from both operational and architectural points of view. Finally, the integrated infrastructure based system architectures for the CESC were presented in accordance with the physical system requirements, and so were the associated and currently conducted R&D focuses for the system.
Optimizing Flexibility in a Sugar Packaging System
Authors: Levermore David M. , Derby Stephen 
Published: February 2021

Abstract
This paper investigates the optimization of flexibility in production systems. The problems associated with sugar production, at the Sugar Industry of Jamaica, is used as a case study. The lack of flexible packaging machinery is identified as a component of these problems. The paper proceeds to assemble a system capable of effectively accomplishing the packaging of bags of various sizes. A simulation of the system using petri nets is used to validate this project.
Modeling Issues for the Intelligent Simulation of Multibody Dynamics
Authors: Cuadrado Javier , Cardenal Jesús , Bayo Eduardo 
Published: February 2021

Abstract
Current simulation tools for multibody dynamics are not problem dependent, they use the same modeling process to all cases regardless of their characteristics. In addition, real-time simulation of small multibody systems is achievable by existing simulation tools, however, real-time simulation of large and complex systems is not possible with existing methods. This is a challenge that needs to be addressed before further advances in mechanical simulation with hardware-in-the-loop and man-in-the-loop, as well as virtual prototyping are made possible.
This paper addresses the issue of how the modeling process-dependent versus independent coordinates, and descriptor form versus state-space form of the equations of motion-affects the dynamic simulation of multibody systems and how it may be taken into account and added to the concept of intelligent simulation. With this new concept all the factors involved in the simulation process — modeling, equations, solution, etc. — are chosen and combined depending upon the characteristics of the system to be simulated. It is envisioned that this concept will lead to faster and more robust real-time simulators.
Geometrical Properties of the Generalized Inverse and its Application to the Inverse Velocity Analysis of Planar Redundant Manipulators
Authors: Martínez José María Rico , Davidson Joseph K. 
Published: February 2021

Abstract
The geometrical properties of the generalized inverse, a scheme frequently applied to the inverse velocity analysis of redundant manipulators, are presented. The columns of the Jacobian matrix, as well as, the rows of the generalized inverse are identified with infinitesimal screws. Then, many geometric properties of these screws are obtained and summarized, especially those that relate to the location of the row screws that appear in the generalized inverse. These properties are then used to develop a simplified alternative method for computing the generalized inverse of planar redundant manipulators.
Assur’s Groups, AKCs, Basic Trusses, SOCs, etc.: Modular Kinematics of Planar Linkages
Authors: Ceresole E. , Fanghella P. , Galletti C. 
Published: February 2021

Abstract
The paper presents a unified point of view on modular methods of kinematic analysis of planar linkages. It is shown that various approaches adopted in different fields, such as linkage analysis, robot kinematics, variational CAD systems, are based on the common idea of decoupling complex systems of equations by solving sequences of simpler subsystems. These subsystems correspond to modules with particular topological properties. Then, the three main issues of a modular method, namely, systematic topology of the modules, solution algorithms for each module, and module recognition in a given mechanism, are discussed and solutions are provided by means of the general unifying concept of Assur Kinematic Chain (AKC).
Finding All Solutions to Approximate Synthesis of Planar Linkages for Function Generation, Rigid-Body Guidance and Path Generation
Authors: Liu An-Xin , Yang Ting-Li 
Published: February 2021

Abstract
Generally, approximate kinematic synthesis of planar linkage is studied using optimization method. But this method has two defects: i) the initial guesses are hard to determine and ii) the global optimum solution is difficult to find. In this paper, a new method which can find all solutions to approximate kinematic synthesis of planar linkage is proposed. Firstly, we reduce the approximate synthesis problem to finding all solutions to polynomial equations. Polynomial continuation method is then used to find all solutions. Finally, all possible linkages can be obtained. Approximate syntheses of planar four-bar linkage for function generation, rigid-body guidance and path generation are studied in detail and 3 examples are given to illustrate the advantages of the proposed method.
Kinematic Geometry of Wheeled Vehicle Systems
Authors: Sreenivasan S. V. , Nanua P. 
Published: February 2021

Abstract
This paper addresses instantaneous motion characteristics of wheeled vehicles systems on even and uneven terrain. A thorough kinematic geometric approach which utilizes screw system theory is used to investigate vehicle-terrain combinations as spatial mechanisms that possess multiple closed kinematic chains. It is shown that if the vehicle-terrain combination satisfies certain geometric conditions, for instance when the vehicle operates on even terrain, the system becomes singular or non-Kutzbachian — it possesses finite range mobility that is different from the one obtained using Kutzbach criterion. An application of this geometric approach to the study of rate kinematics of various classes of wheeled vehicles is also included. This approach provides an integrated framework to study the kinematic effects of varying the vehicle and/or terrain geometric parameters from their nominal values. In addition, design enhancements of existing vehicles are suggested using this approach.
This kinematic study is closely related to the force distribution characteristics of wheeled vehicles which is the subject of the companion paper [SN96].
The Inverse Force Analysis of a Four-Bar Mechanism With Compliant Input and Output Links
Authors: Yin J. P. , Matthew G. K. , Duffy J. 
Published: February 2021

Abstract
A closed-form inverse force analysis was performed for a planar four-bar mechanism with a rigid coupler and frame but with compliance in the form of linear springs in the input and output links. A known force was applied to the coupler link on a line fixed in the plane containing the frame. A sixteenth degree polynomial in the tan-half-angle of the angular displacement of the output link was derived using algebraic elimination. A numerical result is presented which verifies the solutions.
A Coordinate Invariant Formulation of the Dynamics of Cooperating Robot Systems
Authors: Ploen Scott R. , Park Frank C. 
Published: February 2021

Abstract
In this article we formulate the dynamics of cooperating robot systems using standard ideas and notation from the theory of Lie groups. Beginning with the coordinate-invariant formulation of robot dynamics introduced in Ploen and Park (1995), we extend these results to develop the equations of motion of a system of N cooperating robots manipulating a common workpiece. In the resulting dynamic equations the mass matrix, Jacobian, Coriolis, and gravity terms of the closed chain system admit concise block-triangular factorizations in terms of simple linear operators on se(3), the Lie algebra of the Euclidean group SE(3). A straightforward manipulation of the equations of motion and the kinematic constraints leads to a closed-form expression for the forces of constraint in which the robot parameters appear in a transparent manner.
An Efficient Trajectory Planning Method for Binary Manipulators
Authors: Lees David S. , Chirikjian Gregory S. 
Published: February 2021

Abstract
Binary manipulators have actuators with only two stable states. Therefore, they can reach only a finite number of locations. Compared to a manipulator built with continuous actuators, a binary manipulator provides reasonable performance, robustness, and is relatively inexpensive (up to an order of magnitude cheaper). The number of states attainable by a binary manipulator grows exponentially with the number of actuators. This makes brute force calculation of the inverse kinematics impossible for binary manipulators with many actuators. This paper presents a combinatorial method for planning trajectories for a binary manipulator while reducing the search space to a manageable size. Despite the discrete nature of binary actuation, it also creates motions that follow a specified trajectory accurately (in both position and orientation) without large deviations of the end-effector from the specified path.
Experimental and Finite Element Modal Analyses of Planar Mechanisms With Three-Dimensional Geometries
Authors: Smaili Ahmad , Bagci Ismail 
Published: February 2021

Abstract
This article presents the results of numerical and experimental modal analyses of a planar four-bar (4R) mechanism having three dimensional geometry due to the offsets between its links. An experimental mechanism is built and modern modal testing techniques are used. A five-node isoparametric finite element is developed and used to model the mass and flexibility of the links and joints, link offsets, and drive and load shafts. The results obtained from the finite element solution matched closely the experimental results, a testimony to the accuracy of the proposed element. The results indicated that link offsets have considerable influence on the dynamic characteristics of a mechanism system and should be considered in dynamic modeling of planar mechanisms.
Two Precision Position Synthesis of Planar Linkages With Positional Rectification
Authors: Mirth John A. 
Published: February 2021

Abstract
Precision position synthesis is used to generate planar linkages that pass through two exact positions and an additional number of approximate positions. The approximate positions provide a means of rectifying the solution linkages such that all solutions presented are more likely to describe a motion that remains within acceptable positional bounds. The rectification method involves the development of three different numerical algorithms that may be applied to a particular step in the dyad/triad method of precision position synthesis. The three algorithms presented can be applied in a variety of combinations to allow for the synthesis of both simple (four-bar) and complex (multiloop) planar linkages.
Nonlinear Dynamics and Vibrations of Three Dimensional Multibody Tracked Vehicles
Authors: Shabana A. A. , Choi J. H. , Lee H. C. 
Published: February 2021

Abstract
A three dimensional model that includes significant details is developed for the nonlinear dynamic analysis of large scale multi-body tracked vehicle systems. In this model, the joint articulations of the track chains are taken into consideration so as to allow the developement of a computational procedure for the analysis of the vibrations and the contact forces of the multibody tracked vehicles. The three dimensional vehicle system is assumed to consist of three kinematically decoupled subsystems which include the chassis subsystem, and two track subsystems. A recursive approach for formulating the nonlinear equations of the vehicle based on the velocity transformation is used in this investigation in order to reduce the number of equations, avoid the solution of a system of differential and algebraic equations, and avoid the use of nonholonomic constraints to describe the rotations of the sprockets. The singular configurations of the closed kinematic chains of the tracks are also avoided by using a penalty function approach to define the constraint forces at selected secondary joints of the tracks. Detailed three dimensional nonlinear contact force models that describe the interaction between the track links and the vehicle components such as the rollers, sprockets, and idlers as well as the interaction between the track links and the ground are developed and used to define the generalized contact forces associated with the vehicle generalized coordinates. In particular, body and surface coordinate systems are introduced in order to define the spatial contact conditions that describe the dynamic interaction between the teeth of the sprockets and the track link pins. These conditions provide the forces necessary for driving the tracked vehicle. The effect of the tangential friction forces on the stability of the motion of the vehicle is also discussed in this investigation. A computer simulation of a tracked vehicle that consists of one hundred and six bodies and has one hundred and twenty degrees of freedom is presented in order to demonstrate the use of the formulations presented in this study. A simple formula that can be used to predict the steady state velocity of the vehicle when the sprockets rotate with a constant angular velocity is presented and used to verify the numerical results obtained from the nonlinear dynamic simulation of the multibody vehicle.
Dynamic Analysis of Flexible Mechanisms With Clearances
Authors: Wang Yu (Michael) , Wang Zaiping 
Published: February 2021

Abstract
A finite element method in time is presented for the periodic solution of vibrating elastic mechanisms with clearances. The solution of motion is made possible by utilizing time finite elements which discretize the forcing time period into a number of time intervals. During each interval, the solution form is derived from a Hamilton’s law of varying action. The periodic response is described in terms of a set of temporal nodes of all spatial degrees of freedom of the system, yielding a block-diagonal nonlinear algebraic system to be solved iteratively. The suggested method is applied to an example problem of cam-driven valve train, demonstrating the effectiveness of the method in dealing with multiple clearance nonlinearities.