bluuebunny/crossref_metadata_2025 huggingface dataset:
Direct Differentiation Methods for the Design Sensitivity of Multibody Dynamic Systems
Authors: Serban Radu , Freeman Jeffrey S.
Published: February 2021

Methods for formulating the first-order design sensitivity of multibody systems by direct differentiation are presented. These types of systems, when formulated by Euler-Lagrange techniques, are representable using differential-algebraic equations (DAE). The sensitivity analysis methods presented also result in systems of DAE’s which can be solved using standard techniques. Problems with previous direct differentiation sensitivity analysis derivations are highlighted, since they do not result in valid systems of DAE’s. This is shown using the simple pendulum example, which can be analyzed in both ODE and DAE form. Finally, a slider-crank example is used to show application of the method to mechanism analysis.
Hider: A Methodology for Early-Stage Exploration of Design Space
Authors: Reddy Sudhakar Y.
Published: February 2021

This paper describes HIDER, a methodology that enables detailed simulation models to be used during the early stages of system design. HIDER uses a machine learning approach to form abstract models from the detailed models. The abstract models are used for multiple-objective optimization to obtain sets of non-dominated designs. The tradeoffs between design and performance attributes in the non-dominated sets are used to interactively refine the design space. A prototype design tool has been developed to assist the designer in easily forming abstract models, flexibly defining optimization problems, and interactively exploring and refining the design space. To demonstrate the practical applicability of this approach, the paper presents results from the application of HIDER to the system-level design of a wheel loader. In this demonstration, complex simulation models for cycle time evaluation and stability analysis are used together for early-stage exploration of design space.
Formulation and Implementation of Nonholonomic Constraints in the Analysis of Multibody Systems Using Joint Coordinates
Authors: Balling Claus
Published: February 2021

A general formulation for analysis of spatial multibody systems subjected to nonholonomic constraints is presented. Nonholonomic constraints are usually formulated in Cartesian coordinates constraining the relative velocity or acceleration between some (fixed or moving) points on two bodies in mutual interaction or a point on one body with respect to ground.

The formulation involves a specific type of nonholonomic constraint (rolling disk on a surface) in terms of joint coordinates and perform the implementation in a general purpose program.
CAD and Optimization of Spur and Helical Gear Sets
Authors: Metwalli Sayed M. , El Danaf Ehab A.
Published: February 2021

The present work is an application of Computer Aided Design and optimization techniques to solve the problem of designing a pair of gears. The CAD programs have the initial freedom to change the design variables: the module, the number of teeth, the face width, and the material through a data base display, and a full detailed design stage that applies the AGMA bending and contact number checking criteria, and the bending fatigue strength and the surface endurance strength criteria. Other programs are also linked to optimize spur gears under the objective of minimizing the volume. The design vector is taken to be the module, the number of teeth, and the face width, with the interaction between bending and contact stress constraints. These programs were utilized to study the behavior of the optimum parameters for a full range of cases. Charts of the optimum results are plotted. For optimizing helical gears, the design vector is taken as the module, the number of teeth, the face width, and the helix angle. A comparison is made between values of the objective function and optimum parameters for spur and helical gears for a wide range of cases. A comparison is also made of the results with other previous works of optimization and proved that the approach presented here gives better optimum results for the same loading case.
Modeling of a Controlled Service Platform: Proposals for an Optimal Layout
Authors: Eschenauer H. , Neuser P.
Published: February 2021

As an example of complex systems a controlled service platform is treated, for which an improved design has to be determined. Two substitute models that simplify the real system to a different degree are employed for the calculation of the structural responses by means of the Finite-Element (FE)-Method. The structural analyses are limited to the consideration of the system’s free vibration behaviour, as well as the displacements and stresses in an extreme load case, called bumper impact. A further system reduction is achieved by using sub-structuring and the reduction according to Guyan. The structural optimization problem is solved by means of the optimization procedure SAPOP that is based on the so-called Three-Columns-Concept. Results are given for a design optimized with respect to mass, first eigenfrequency, and stress.
Qualitative Evaluation of Engineering Designs Using Fuzzy Logic
Authors: Roy Rajkumar , Parmee Ian C. , Purchase Graham
Published: February 2021

The paper describes a Qualitative Evaluation System developed using a fuzzy expert system. The evaluation system gives a qualitative rating to design solutions by considering manufacturability aspects, choice of materials and some special preferences. The information is used in decision support for engineering design. The system is an integrated part of a decision support tool for engineering design called the ‘Adaptive Search Manager’ (ASM). ASM uses an adaptive search technique to identify multiple design solutions for a 12 dimensional Turbine Blade Cooling System design problem. Thus the task has been to develop a fuzzy expert system that can qualitatively evaluate any design solution from a design space using a realistically small number of fuzzy rules. The developed system utilises a knowledge separation and then a knowledge integration technique. The design knowledge is first separated into three categories: inter variable knowledge, intra variable knowledge and heuristics. Inter variable knowledge and intra variable knowledge are integrated using a concept of “compromise”. The qualitative evaluation system can evaluate any design solution within the 12 dimensional design space, but uses only 44 fuzzy rules and one function that implements the inter variable knowledge.
Recent Refinements in the Multi-Point Approximation Method in Conjunction With Adaptive Mesh Refinement
Authors: van Keulen Fred , Toropov Vassili , Markine Valery
Published: February 2021

Application of the Multi-point Approximation Method (MAM) to structural optimization is considered. Structural analyses are performed by means of the finite element method with Adaptive Mesh Refinement (AMR). The required discretization errors are changed during the optimization process to achieve a higher computational efficiency.

A straightforward combination of the MAM and AMR may yield complications, which are discussed in detail. Therefore, several modifications in the MAM are necessary. An alternative strategy for determining the explicit approximation functions using a weighted least-squares fitting is proposed. The applied weight coefficients reflect the levels of the discretization errors. The approximation functions are fitted with a sub-set of the available structural response analyses. An alternative move limit strategy is given.

On the basis of several numerical examples it is shown that the proposed modifications improve the convergence characteristics of the MAM when combined with AMR. Moreover it is demonstrated that the proposed refinements are also beneficial for optimization of systems with noisy objective and constraint functions.
Sensitivity Analysis for Optimization of Flexible Multi-Body Systems
Authors: Behar Linda , Braibant Vincent
Published: February 2021

A method for the sensitivity analysis of the dynamic transient response of flexible multi-body systems is presented. The main objectives in developing the method are: 1) to reduce cost and achieve accuracy of the sensitivity analysis, 2) to develop a performent tool for the sensitivity analysis and the optimization of flexible multi-body systems. Practical applications are located in the automotive industry, with the optimization of the driving behavior of vehicles and in the aerospace industry. The method consists in solving simultaneously the dynamic and the sensitivity problem. Two simple examples are presented to demonstrate the method, one for a dynamic response problem, and the second one for a kinematic problem.
A Direct Displacement Solution to the Dodecahedron Variable Geometry Truss Manipulator
Authors: Xu Li-Ju , Yang Sui-Xian , Zhou Zhao-Fei
Published: February 2021

Homotopy continuation algorithms for solving the direct position problem of the dodecahedron variable geometry truss manipulator are proposed in this paper. The homogeneous equations and the division of groups are presented which give the lowest Bezout number. The solution procedure is given in detail. A numerical example is presented for illustration.
Computerized Design, Generation and Simulation of Meshing and Contact of Modified Flender Worm-Gear Drives
Authors: Seol I. H. , Litvin Faydor L.
Published: February 2021

The worm and worm-gear tooth surfaces of existing design of Flender gear drive are in line contact at every instant and the gear drive is very sensitive to misalignment. Errors of alignment cause the shift of the bearing contact and transmission errors.

The authors propose :

(1) Methods for computerized simulation of meshing and contact of misaligned worm-gear drives of existing design

(2) Methods of modification of geometry of worm-gear drives that enable to localize and stabilize the bearing contact and reduce the sensitivity of drives to misalignment

(3) Methods for computerized simulation of meshing and contact of worm-gear drives with modified geometry

The proposed approach was applied as well for the involute (David Brown) and Klingelnberg type of worm-gear drives. Numerical examples that illustrate the developed theory are provided.
Assembly Modeling and Sequence Planning Based on the Kinematics of Features
Authors: Ling Zhi-Kui
Published: February 2021

A feature-based model is proposed for assembly sequence planning automation. The fundamental assembly modeling strategy for a product is based on the mating features of its components. The objectives of this study are to integrate assembly planning of a product with its CAD model, generate a correct and practical assembly sequence, and establish a software system to carry out the planning process. A disassembly approach in assembly planning is used in this study. The degree of freedom information between two mating features is used to characterize their kinematic conditions. The intersection calculation of the degrees of freedom on all features of a component provides its local degree of freedom which is used to set up functional precedence relationship. In some cases where functional precedence relationship can not be detected by geometric reasoning, clipping of the known “common sense” relationship is applied by an user. A bounding box checking approach is used to ensure no global collision during assembly. Furthermore, a set of criteria and heuristic rules based on assembly feasibility, manipulability, assembly direction, cost and stability is used to choose a good assembly sequence.
Multiple Criteria Optimization of Finish Turning Operations Based on a Hybrid Model
Authors: Da Z. J. , Sadler J. P. , Jawahir I. S.
Published: February 2021

In this paper a multiple criteria optimization method is used to achieve the optimum selection of cutting conditions and tool inserts for finish turning operations. The utility function which maps criterion vectors into the real line is constructed based on tool-life and material removal rate. This unified objective function serves as an arbiter balancing the values of the individual objective functions. Different formats of utility functions are developed and their physical significance is analyzed. Other major machining performance characteristics such as surface roughness, cutting force, power requirements and chip breakability are used as constraints to define acceptable limits on these criteria, along with the limits on the ranges of the process variables. A hybrid process model which uses combinations of the metal cutting theories and an expandable database of experimental results is used to describe the interrelationships between the machining performance criteria and the process variables. Nonlinear programming techniques coupled with numerical methods for data interpolation are then applied to identify optimum process conditions for a given tool insert. Furthermore, for any specified application a cutting tool can be selected through comparative analyses. A sample case for a typical tool insert was studied and the results are presented.
Motion Planning With Convex Swept Volume Segments
Authors: Wu Chiusheng , Mayne Roger W.
Published: February 2021

This paper presents a swept volume approach for distance-to-contact computation in motion planning. The approach is based on approximating the swept volumes of moving objects with convex segments formulated for the use of quadratic programming in distance-to-contact calculations. This swept volume strategy is designed to conservatively estimate the distance-to-contact between moving and static objects and is well suited for the planning of motions using optimization methods. It has been adapted to obtain convenient distance-to-contact gradient information which is an important factor in the application of efficient optimization algorithms to the motion planning process. The paper describes the generation of the swept volume segments and applies the process to examples of robot motion planning in three dimensions using an SQP optimization strategy.
Reliability Modeling in Design for Remanufacture
Authors: Shu Lily H.
Published: February 2021

Remanufacture involves the production-batch disassembly, cleaning, replacement and refurbishment of worn parts in defective or obsolete products. For appropriate products, remanufacture offers significant economic and ecological advantages over other end-of-life options. Since the essential goal of remanufacture is part reuse, the reliability of components is important. The goal of this work is to consider reliability effects on life-cycle costs to enable design for reuse.

A reliability model is developed to describe systems that undergo repairs performed during remanufacture or maintenance. First, the behavior of the model and preliminary experimental verification of the model are described. The model allows replacement of failed parts with both the same and different types of parts. An example simulation applied the reliability model to compare the effects on life-cycle cost of various combinations of mechanical components in a series system.
Quantifying Design and Manufacturing Robustness Through Stochastic Optimization Techniques
Authors: Kazmer David , Barkan Philip , Ishii Kosuke
Published: February 2021

Critical design decisions are often made during the detailed design stage assuming known material and process behavior. However, in net shape manufacturing processes such as stamping, injection molding, and metals casting, the final part properties depend upon the specific tool geometry, material properties, and process dynamics encountered during production. As such, the end-use performance can not be accurately known in the detailed design stage. Moreover, slight random variations during manufacture can inadvertently result in inferior or unacceptable product performance and reduced production yields. These characteristics make it difficult for the designer to select the tooling, material, and processing details which will deliver the desired functional properties, let alone achieve a robust design which is tolerant to process variation.

This paper describes a methodology for assessing the design/manufacturing robustness of candidate designs at the detailed design stage. In the design evaluation, the fundamental sources of variation are explicitly modeled and the effects conveyed through the manufacturing process to predict the distribution of end-use part properties. This is accomplished by utilizing optimization of manufacturing process variables within Monte Carlo simulation of stochastic process variation, which effectively parallels the industry practice of tuning and optimizing the process once the tool reaches the production floor. The resulting estimates can be used to evaluate the robustness of the candidate design relative to the product requirements and provide guidance for design and process modifications before tool steel is cut, as demonstrated by the application of the methodology for dimensional control of injection molded parts.
Designing for Material Separation: Lessons From Automotive Recycling
Authors: Coulter Stewart , Bras Bert , Winslow Gerald , Yester Susan
Published: February 2021

Virtually all of the material in today’s automobiles can technically be recycled. The challenge facing engineers is making this recycling process economical, especially for materials in such components as seats and instrument panels. Recycling these components requires the different materials to be separated so that each can be recycled individually. This separation can be accomplished either manually, where workers disassembly and sort the vehicle components by hand, or mechanically, where the vehicle is shredded and the materials sorted by properties such as conductivity and density. In this paper, the usefulness of including likely separation techniques in DFR guidelines is discussed. Three vehicles were dismantled at the VRDC as part of an effort to establish a baseline of current vehicle recyclability. Concurrently, this allowed examination of the effectiveness of the early design for recycling (DFR) efforts. The applicability of common design guidelines to the two types of separation is discussed, and a simple method for determining the appropriate separation process in the early stages of design is presented.
Enhancing Design for Disassembly: A Benchmark of DFD Software Tools
Authors: Hrinyak Matthew J. , Bras Bert , Hoffman William F.
Published: February 2021

Manufacturers are becoming responsible for their products when they reach the end of their operational lives. Disassembly will be an integral part of this new responsibility. The logical remedy is to begin including design for disassembly guidelines and analyses in existing product design processes. Software tools have been and continue to be developed to perform such analyses. However, not all of these tools are of equal caliber and we cannot expect designers to use all of the tools that are available to them. In this paper, we examine four existing software tools available to designers for inclusion in their design processes. We compare the results from each of the software tools and show how the growing pool of potential software tools can be prioritized according to how they best meet the needs of designers.
An Investigation of Vector and Parallel Processing Applied to Solid Modeling
Authors: Pai Navin , Henderson Mark
Published: February 2021

Solid modeling is a very useful industrial tool in the manufacture and design of industrial parts and assemblies. As a tool in the industrial workplace it has to be able to respond quickly to changes in design. To do this, the intersection algorithms between the solids have to be speeded up. Optimizations such as vector and parallel processing traditionally supported by supercomputers have the potential to solve this problem.

A solid modeler was developed based on the boundary representation approach using a half-edge data structure. Those parts of the solid modeler code that could be vectorized were identified. A method was tested which allows loops involving linked lists to vectorize. It was also shown that this solid modeler has an inherent parallelism that can be exploited. Results are presented for vectorization and parallelization. The practical limits to both vectorization and parallelization are highlighted. Improvements to the geometric intersections algorithms are suggested to take advantage of vector and parallel processing. Results of the speedups possible using these algorithms are presented.
Plan-Based Evaluation of Designs for Microwave Modules
Authors: Hebbar Kiran , Smith Stephen J. J. , Minis Ioannis , Nau Dana S.
Published: February 2021

This paper describes EDAPS, an integrated system for designing and planning the manufacture of microwave modules. Microwave modules are complex devices having both electrical and mechanical properties, and EDAPS integrates electrical design, mechanical design, and process planning for both the mechanical and electrical domains.

Since EDAPS generates process plans concurrently with design, we are developing ways for EDAPS to provide feedback about manufacturability, cost, and lead time to the designers, based on the process plans to be used in the manufacture of their designs.
Detection and Prevention of Gouging in Multi Axis Machining of Freeform Surfaces
Authors: Elber Gershon , Cohen Elaine
Published: February 2021

The detection of gouging and collisions in multi-axis machining is a profoundly difficult problem that prohibits its wide spread practical use. In this paper, we investigate the use of symbolic tools to detect tool gouging in 5-axis machining tool-path of sculptured surfaces. Further, we also present a heuristic approach to eliminate the gouging, whose result is a gouge free 5-axis toolpath.
Function Driven Design Selection of Plastic Injection Molding Features
Authors: Wood Stephen L.
Published: February 2021

Capturing the basic reasoning of why and how a design is developed is important in fully preserving and documenting the design of industrial products. To maintain captured design information and reuse the information during solution retrieval requires different types of information transferral and preservation than those traditionally used in CAD systems. This paper develops the basic database structure for preserving and transferring the design information along with using the reasoning (functional properties) in the search for solutions. The basis for this paper was the development of an architecture for a function driven mechanical design solution library that can be applied to multiple design areas. The solution library uses a specific architecture to maintain and transfer the information between features. The architecture allows the designer to retrieve saved solutions to a CAD system through the desired functional parameters, transfer the retrieved solution’s information, and to capture the reasoning or intent of the design during development.
Virtual Mechanical Assembly on a PC-Based System
Authors: Pere E. , Langrana N. , Gomez D. , Burdea G.
Published: February 2021

This paper describes a virtual reality system in which the user can perform assembly tasks in a simulated workshop. This PC-based VR system integrates a force feedback device, the Rutgers Master II. It allows the user to feel the interaction with virtual tools and makes the training task in a synthetic environment closer to reality. The application also allows object manipulation with mechanical behavior, navigation, collision detection and other features.
Iterative Part Design With a Virtual Reality Interface
Authors: Trika S. N. , Banerjee P. , Kashyap R. L.
Published: February 2021

A virtual reality (VR) interface to a feature-based computer-aided design (CAD) system promises to provide a simple interface to a designer of mechanical parts, because it allows intuitive specification of design features such as holes, slots, and protrusions in three-dimensions. Given the current state of a part design, the designer is free to navigate around the part and in part cavities to specify the next feature. This method of feature specification also provides directives to the process-planner regarding the order in which the features may be manufactured.

In iterative feature-based design, the existing part cavities represent constraints as to where the designer is allowed to navigate and place the new feature. The CAD system must be able to recognize the part cavities and enforce these constraints. Furthermore, the CAD system must be able to update its knowledge of part cavities when the new feature is added. In this paper, (i) we show how the CAD system can enforce the aforementioned constraints by exploiting the knowledge of part cavities and their adjacencies, and (ii) present efficient methods for updates of the set of part cavities when the designer adds a new feature.
Design of MEMS via Efficient Simulation of Fabrication
Authors: Hubbard Ted J. , Antonsson Erik K.
Published: February 2021

A novel model is introduced to simulate the fabrication of MEMS (Micro Electro Mechanical Systems). This approach provides computationally efficient and geometrically accurate simulation results by hybridizing a geometrical and cellular approach. Existing simulation methods, including numerical and analytical models, are examined. Factors influencing simulation results, such as fabrication conditions and etching regimes, are introduced and discussed. Simulation examples are presented and non-ideal effects are considered.
Computer Supported Product Development Through Integration of CAD, Rapid Prototyping and 3D-Digitizing Helps the Productivity of Former East German Companies
Authors: Grote Karl-H. , Beyer Christiane
Published: February 2021

In socialistic countries, customer satisfaction and the market conditions were not of high priority: Some selected parts of the market products were of satisfactory costs and quality to customers. Quality and costs of a product decide on its success in the world-wide market. The wishes and expectations of the customer for a high-quality and low-priced product continue to grow, however, with the desire for faster availability of this product. The customer determines also the delivery time and other competitive factors as the durability of the product. At present the trend goes towards shorter product life cycles, which in turn requires reduced time spent on the product development. With these complex market requirements and growing diversity of the products the engineer faces new challenges in his development tasks. It can be paraphrased as follows: In reduced lifecycles a quality-assured and advantageous product has to be developed despite increasing complexity of the design and demands for reduction of material used, manpower and monetary spending.

For the solution of this complex problem the following suggestions are tested and implemented:

• Structured design process for the development process,

• Simultaneous work where ever possible during the development stages,

• Employment of modern resources for the product development,

• Use of information technology and

• Implementation of rapid prototyping for models and in secondary manufacturing processes.

An important research field at the Department of Mechanical Engineering Design at the Otto-von-Guericke-University Magdeburg is research and further development of productive procedures and tools for the realization of a computer integrated product development process. This process includes the effective application of technologies to produce the prototypes for presentation, producibility analysis and production.

Of particular interest is the closed process chain (loop) from Solid Modeling via Rapid Prototyping and 3D-Digitizing where the entry point of this process chain depends on the needs of the application or particular interest of the innovating company. Information for faster and more competitive preparation, verification and Re-Engineering of existing and established products, which have to be adjusted to the world-market needs, will be made available. The results of this applied research offer opportunities to display new developed products for the lagging industries in the former East Germany, and furthermore arranging for necessary venture capital to produce the product, to gain information about possible suppliers and manufacturing opportunities in order to minimize the investors’ risks of an enterprise.
Collaborative Design System for Electromechanical Products
Authors: Narikawa Noboru , Takahashi Kazuo
Published: February 2021

This paper gives an overview of a collaborative design system (CDS) for electromechanical products. To reduce design costs and to manufacture high-quality products, it is well known that concurrent engineering (CE) is a very efficient approach. Three-dimensional (3D) CAD system and engineering database system are essential components of CE. The CDS is an environment to realize CE. By creating 3D models in a computer and performing some simulations such as mechanical, electronic, software simulation and integrated simulations, it is possible to estimate functions, assemblability, manufacturability and so on, before making prototype models.

In this paper, we outline the CDS and mainly discuss the total information management system (TIMS) which makes an important role of the CDS. This paper describes the implementation experience of some functions of the TIMS.
Development of a Disassembly Evaluation Tool
Authors: Kroll Ehud
Published: February 2021

A method for evaluating the ease of disassembly of products is presented. Its primary use is in designing products for recycling and making environmentally-related decisions, but it is also relevant to servicing and maintenance. The evaluation procedure is centered around a spreadsheet-like chart and uses a catalog of task difficulty scores. The scores were derived from work-measurement analyses of standard disassembly tasks and provide a means of identifying weaknesses in the design and comparing alternatives quantitatively. The requirements and considerations in developing the design tool are examined in light of the general problem of manufacturability metrics. The limitations of the method and future extensions are discussed.
The Validation of a Taxonomy for Manufacturability Design Requirements
Authors: Gershenson John K. , Stauffer Larry A.
Published: February 2021

In this paper, we present the results of a study to validate a taxonomy of manufacturing issues. This taxonomy serves as a checklist of manufacturing issues which should be considered during the conceptual and detail design stages of the product definition process.

Subjects in this validation study were given one of three different levels of the taxonomy at one of two different stages of design and asked to perform design tasks. The subjects’ use of the taxonomy and their ability to develop meaningful requirements with their given taxonomy were recorded. The data was analyzed using an analysis of variance technique to compare subjects using different taxonomy levels at different stages of the design process. The analysis shows that the taxonomy and the underlying methodology of creating and using the taxonomy helps designers manage product requirements during the early stages of the design process. The analysis also shows that the taxonomy needs to be used in a methodical manner to maximize its effectiveness.
Capturing Design Rationale in Engineering Contexts
Authors: Ruecker Lukas S. F. , Seering Warren P.
Published: February 2021

In our research we have focused on capturing design rationale — that is, the reasons that underlie design decisions — during the early stages of the product development process. Capturing rationale is important because it allows others to understand decisions, make changes, and review a conclusion in the light of new information.

In this paper we describe a well-grounded computer-supportable approach to capturing rationale in an engineering setting. At the heart of this approach is a computationally efficient and dynamically extensible representation of the context in which design decisions are made. We also describe a program that uses this representation to automatically chunk, classify, and integrate explanations offered by engineers when justifying design decisions.
A Concurrent Engineering Methodology for Small Companies
Authors: Carlson Susan E. , Kemser Hans-Peter , Ter-Minassian Natasha
Published: February 2021

Concurrent engineering is a design philosophy that has been accepted in large corporations, but generally is not used within small companies. This paper discusses the design approaches observed within five small to medium-sized companies. Based on these observations, a concurrent engineering methodology is proposed that is focused on the needs of small companies. An example is used to show how this methodology is applied.
Improving the Design Process by Predicting Downstream Values of Design Attributes
Authors: Szykman Simon
Published: February 2021

This paper presents a computational approach to developing design space models that are utilized to improve the design process by predicting values of downstream design attributes based on information available at early stages, such as preliminary design specifications. The predictive models are similar in function, though not in form, to the internal (mental) models created by experienced designers; however, the advantages of these models are that it may be possible to construct them in the absence of a designer’s internal models, and that they can be passed on to and used by less experienced designers. Once created, the computational models aid designers in exploration of design alternatives and to reduce design costs and product development time.
A Comparative Analysis of the Theory of Inventive Problem Solving and the Systematic Approach of Pahl and Beitz
Authors: Malmqvist Johan , Axelsson Roger , Johansson Mikael
Published: February 2021

This paper presents a comparative analysis of two design methodologies; the Theory of Inventive Problem-Solving (TIPS) and the systematic approach of Pahl and Beitz (SAPB).

The methodologies are compared with respect to a number of aspects; similarities and differences are highlighted. It is then suggested that a more powerful methodology may result if the methodologies are unified and that such a unification should use SAPB as an underlying design process model being complemented by TIPS elements at certain points. This is because the SAPB has a wider scope as a design process model, covering the whole process from task clarification to detail design and component as well as systems design, whereas TIPS features some very useful elements (engineering systems evolution laws, standards and principles) that are not included in the SAPB.
Functional Evaluation Based on Function Content
Authors: Shimomura Yoshiki , Tanigawa Sadao , Takeda Hideaki , Umeda Yasushi , Tomiyama Tetsuo
Published: February 2021

Function is a key concept to integrate design object modeling and design process modeling in design. We here propose the FEP (Functional Evolution Process) model in order to integrate design object modeling and design process modeling. In the FEP model, the model of a design object is evolved through three steps, i.e., function description, function actualization and function evaluation. Function description is the step in which a designer modifies required functions of a design object. Function actualization depicts a process to obtain physical descriptions from functional description. Function evaluation is a process to measure realizability of functions of the design object. However, among other steps, how to treat the function evaluation is one of the most important theme, because evaluation executed by designers is based on subjective, ambiguous and tacit standards.

We discuss a methodology for evaluating function and propose the function content that quantifies functions and enables evaluation of functions. The function content is a similar concept of Shannon’s information content and we show an example of functional optimization based on this scheme.
Design for Variety: A Methodology for Understanding the Costs of Product Proliferation
Authors: Martin Mark V. , Ishii Kosuke
Published: February 2021

This paper further develops the previously introduced concept of Design for Variety (DFV). Our study seeks a tool that enables product managers to estimate the cost of introducing variety into their product line. This will help them to maximize market coverage while maintaining required profit margins. Variety incurs many indirect costs that are not always well understood or are difficult to capture. These costs are often not considered by people making the decision about introducing variety. Our DFV model attempts to capture these indirect costs through the measurement of three indices: commonality, differentiation point, and set-up cost. These indices will allow the decision makers to estimate some of the generally unmeasurable costs of providing variety. We conclude this paper by discussing our validation plans for testing the model in industry.
A Grammar Driven Data Translation System for Computer Integrated Manufacturing
Authors: Niebur Glen L. , Chase Thomas R.
Published: February 2021

Integration of engineering software continues to be an important topic in mechanical design and manufacturing. One integration technique which has been proposed is to store a complete product representation in a single database using a database management system. In order to integrate existing CAE applications which are not designed for use with a DBMS, a method for importing and exporting data to the database is needed. A system for recognizing and translating a large class of engineering data, those data formats which can be described by regular grammars, is proposed.
Classification, Rotatability and Branch Identification of Simple RCRCR Mechanisms
Authors: Dou Xiaohong , Ting Kwun-Lon
Published: February 2021

A comprehensive algorithm and criterion for the rotatability and branch identification of RCRCR spatial mechanisms with zero offset at the revolute joint between the cylindrical joints are presented. The results are believed the first successfully attempt which resolves the mobility and branch identification problems of non-bimodal spatial mechanisms.

In this article, the concept of virtual linkage is proposed. A simple RCRCR mechanism is regarded as a spherical 5R linkage with one cylindroid surface constraint formed by a virtual bimodal linkage. The treatment on the rotatability of virtual bimodal linkages is identical to that of the planar and spatial bimodal linkages. Thus, from the rotatability point of view, simple RCRCR mechanisms and Stephenson six-bar linkages can be grouped together. They have the similar rotatability and branch features. The results include the classification and mobility criterion, and an algorithm for branch identification, which are equally effective for any linkage inversion, any type of linkage synthesis problem, and any number of precision positions.
An Efficient Algorithm for Accurate Evaluation of Circularity Tolerance
Authors: Anand Sam , Jaganathan Sridhar , Damodarasamy Sampath
Published: February 2021

This paper presents a new and accurate algorithm for assessing circularity tolerance from a set of data points obtained from a Coordinate Measuring Machine (CMM). This method, called Selective Zone Search algorithm, divides the workspace into small sectors called search zones and searches for the extreme points in these zones. These extreme points are used to draw a pair of concentric circles with minimum radial separation. The radial difference gives the circularity. The methodology has been tested with several example data sets and the results have been compared with the Least Squares method, Minimum Spanning Circle method and the Voronoi Diagram method.
Reconfigurable System Analysis for Agile Manufacturing
Authors: Dhumal Ashish , Dhawan Rajiv , Kona Anupama , Soni A. H.
Published: February 2021

Agile manufacturing concept requires an enterprise view and agility embodies concepts like rapid prototyping, reconfigurable equipment, design for upgradability, leveled production and continuous improvement to introduce new products to the market at an affordable price. An agile enterprise needs to consider shop floor issues as well. There is an increase in use of reconfigurable tooling in industries, and much of it is in need of integration. A need exists for improvement in building of production tooling which can be reconfigured when need arises with the smallest possible changeover time.

This paper analyzes different production scenarios of a forging cell designed using Petrinet theory. Petrinet theory is effective in design and synthesis of discrete event systems, especially agile systems and incorporates the control logic of the system. The objective of the study was to quantify agility of the system by determining system characteristics at different operating conditions and its ability to accommodate different products. The deterministic model is analyzed using a simulation software package. Conclusions obtained from this study are summarized for evaluation of reconfigurable systems focused on assembly aspects.
Enabling Technologies for Virtual Parts Handling Environment: An Overview
Authors: Liou F. W.
Published: February 2021

Due to the current advances in simulation, computer graphics, robotics, and other related technologies, virtual environment has become a future trend in design and development of new products. This paper summarizes the current enabling technologies to develop a virtual environment for parts handling applications, such as parts feeding, assembling, and robotic grasping. A special focus is on developing a physically-based simulation system, which is the core of a virtual parts handling environment. Critical technologies such as object collision detection and response, contact modeling and friction modeling are reviewed. The technological challenges in these areas are also pointed out.
A Newly Developed Algorithm for Treating the Coupled Dynamic Response of Robotic Fixtureless Assembly
Authors: Shagal Genady , Meguid Shaker A.
Published: February 2021

The coupled dynamic response of two cooperating robots handling two flexible payloads for the purpose of fixtureless assembly and manufacturing is treated using a new algorithm. In this algorithm, the equations describing the dynamics of the system are obtained using Lagrange’s method for the rigid robot links and the finite element method for the flexible payloads. A new time integration scheme is developed to treat the coupled equations of motion of the rigid links for a given displacement of the flexible payloads. The finite element equations of the flexible payloads are then treated using an implicit approach. The new algorithm was verified using simplified examples and was later used to examine the dynamic response of two cooperating robot arms manipulating flexible payloads which are typical of the automotive industry.
An Efficient Inverse Acceleration Analysis of In-Parallel Manipulators
Authors: Martínez José María Rico , Duffy Joseph
Published: February 2021

A very simple novel expression for the accelerations of the six prismatic actuators, of the HPS connector chains, of a 6 degree of freedom in-parallel manipulator is derived. The expression is obtained by firstly computing the “accelerator” for a single HPS connector chain in terms of the joint velocities and accelerations. The accelerator is a function of the line coordinates of the joint axes and of a sequence of Lie products of the same line coordinates. A simple expression for the acceleration of the prismatic actuator is obtained by forming the Klein form, or reciprocal product, with the accelerator and the coordinates of the line of the connector chain. Since the Klein form is invariant, the resulting expression can be applied directly to the six HPS connector chains of an in-parallel manipulator. The authors believe that this simple method has important applications in the dynamics and control of these in-parallel manipulators where the computing time must be minimized to improve the behavior of parallel manipulators.
Cam Motion Synthesis for Mixed Motion Constraints Using Well-Behaved Polynomials of High Order
Authors: Schönherr Jürgen
Published: February 2021

A method of describing a function by a number of successive polynomials of unrestricted and varying degree has been developed to synthesize a cam motion for mixed constraints. The algorithm is based on the expression of the coefficients of a polynomial in terms of the constraints at interval boundaries. It enables the designer to satisfy numerous motion constraints while at the same time preserving the continuity of motion derivatives up to a high order. Unconstrained boundary values are calculated automatically by using an objective function that minimizes the oscillations of a motion derivative.
Computer-Aided Synthesis of Linkage-Type Straight-Line and Dwell Mechanisms
Authors: Tso Pei-Lum , Yan Shan-Shun
Published: February 2021

The synthesis of the four-bar mechanism has received a substantial amount of attention in the area of straight-line mechanisms. Various geometrical and analytical methods have been developed with numerous papers published in this area over the past few decades. Three primary methods are generally available for synthesis of the linkages. The first approach is the classical Burmester finite separated position synthesis technique. The precision points are assigned for describing the desired straight-line motion (Mahyuddin etc. 1986;Shagan,Fallahi and Lai 1989). The second approach uses the mathematical programming technique for finding the optimal solution which mimimizes the error between the desired straight line and the real tracing points of a linkage (Hwang and Hsiao 1989;Hwang and Lee 1987). The third approach is based on the curvature theory. Any point on the inflection circle generates an approximate straight Tine motion. A series of design charts was set up by Vidosic and Tesar (Vidosic and Tesar 1967) as the basis of synthesizing the mechanisms. However, the direction of the coupler point has generally not been controlled. The constraint was taken into consideration by Hsu (Hsu and Lee 1990).
Leg Lift During Non-Overconstrained Pseudo-Static Walking
Authors: Foo Chee K. , Fichter Eugene F. , Fichter Becky L.
Published: February 2021

A non-overconstrained pseudo-static walking machine has 1 leg joint under position control for every degree-of-freedom of the body. When 1 joint is position controlled on each of 6 legs, leg lift during a step results in 1 unregulated degree-of-freedom of the body. A second joint in one of the 5 legs that maintain contact with the ground must be switched to active position control at the same time that a foot is lifted. In theory any passively controlled joint in the 5 supporting legs may be chosen. However the requirement that no leg be in tension and practical limits on torques available from joint actuators severely restrict choice of both additional joint to actively position control and possible body positions where legs can be lifted.