bluuebunny/crossref_metadata_2025 huggingface dataset:
Neutrophil‐to‐lymphocyte ratio is an independent prognostic marker for feline mammary carcinomas
Authors: Petrucci Gonçalo N. , Lobo Luís , Queiroga Felisbina , Martins José , Prada Justina , Pires Isabel , Henriques Joaquim
Published: February 2021

Blood leukocyte counts and respective derived ratios have been described as potential prognostic markers in several tumours in veterinary oncology. This study aimed to evaluate peripheral blood leukocyte subpopulations and neutrophil‐to‐lymphocyte ratio (NLR) as prognostic factors for feline mammary carcinomas (FMC). Medical records from cats diagnosed with FMC between 2017 to 2019 were reviewed. Cats were included if fully staged, classified as WHO stage I to III, and submitted to mastectomy. Cats were excluded if they had evidence of other diseases. Forty‐nine cats were included. The study endpoints were disease‐free interval (DFI) and tumour‐specific survival (TSS). The median DFI and TSS were 389 days and 528 days respectively. In the univariate analysis, higher values of total white blood cell count (WBC), neutrophil count (NEU) and NLR were identified as significant prognostic factors for both endpoints (P < .05). On the multivariate analysis, NLR remained an independent prognostic factor for TSS (P = .024). In the receiver operating characteristic curve analysis, the estimated cut‐off for WBC was 8.49 × 109/L (DFI and TSS); for NEU was 4.62 × 109/L (DFI) and 6.65 × 109/L (TSS) and for NLR was 2.46. These cut‐offs were significant prognostic factors for DFI and TSS (P < .05). NLR cut‐off remained an independent prognostic factor for both DFI (P = .032) and TSS (P = .043) in the multivariable analysis. Our results suggest that NLR, NEU, and WBC can be important non‐invasive presurgical prognostic markers, and that NLR is an independent prognostic marker for FMC. Prospective studies are warranted to validate its clinical use.
Rates of oxidative ATP synthesis are not augmented beyond the pH threshold in human vastus lateralis muscles during a stepwise contraction protocol
Authors: Bartlett Miles F. , Fitzgerald Liam F. , Kent Jane A.
Published: February 2021

Key points

The oxygen cost of high‐intensity exercise at power outputs above an individual's lactate threshold (LT) is greater than would be predicted by the linear oxygen consumption‐power relationship observed below the LT. However, whether these augmentations are caused by an increased ATP cost of force generation (ATPCOST) or an increased oxygen cost of ATP synthesis is unclear.

We used 31P‐MRS to measure changes in cytosolic [ADP] (intramyocellular marker of oxidative metabolism), oxidative ATP synthesis (ATPOX) and ATPCOST during a 6‐stage, stepwise knee extension protocol.

ATPCOST was unchanged across stages. The relationship between [ADP] and muscle power output was augmented at workloads above the pH threshold (pHT; proxy for LT), whereas increases in ATPOX were attenuated.

These results suggest the greater oxygen cost of contractions at workloads beyond the pHT is not caused by mechanisms that increase ATPCOST, but rather mechanisms that alter intrinsic mitochondrial function or capacity.

Increases in skeletal muscle metabolism and oxygen consumption are linearly related to muscle power output for workloads below the lactate threshold (LT), but are augmented (i.e. greater rate of increase relative to workload) thereafter. Presently, it is unclear whether these metabolic augmentations are caused by increases in the ATP cost of force generation (ATPCOST) or changes in the efficiency of mitochondrial oxygen consumption and oxidative ATP synthesis (ATPOX). To partition these two hypotheses in vivo, we used 31P‐MRS to calculate slopes relating step‐changes in muscle work to concurrent changes in cytosolic phosphates and ATPOX before and after the pH threshold (pHT; used here as a proxy for LT) within the vastus lateralis muscle of eight young adults during a stepwise knee extension test. Changes in muscle phosphates and ATPOX were linearly related to workload below the pHT. However, slopes above the pHT were greater for muscle phosphates (P < 0.05) and lower for ATPOX (P < 0.05) than were the slopes observed below the pHT. The maximal capacity for ATPOX () and ADP‐specific ATPOX also declined beyond the pHT (P < 0.05), whereas ATPCOST was unchanged (P = 0.10). These results oppose the hypothesis that high‐intensity contractions increase ATPCOST and suggest that greater oxidative metabolism at workloads beyond the pHT is caused by mechanisms that affect intrinsic mitochondrial function or capacity, such as alterations in substrate selection or electron entry into the electron transport chain, temperature‐mediated changes in mitochondrial permeability to protons, or stimulation of mitochondrial uncoupling by reactive oxygen species generation.
Virtual Assembly With Construction Kits
Authors: Jung Bernhard , Hoffhenke Martin , Wachsmuth Ipke
Published: February 2021

The CODY1 Virtual Constructor is a knowledge-based system that enables the interactive assembly of 3D visualized mechanical parts to complex and novel aggregates in a virtual environment. Two interaction modalities are provided: The user may (1) either directly manipulate the virtual scene by grasping, moving, and assembling parts using the mouse or similar input devices; or, (2) the user can instruct the system using simple commands in natural language. The basis for these interaction facilities is provided by a knowledge based approach, COAR (“Concepts for Objects, Assemblies, and Roles”%), that is especially tailored towards the representation of ongoing assembly tasks. In COAR, a structured model of a target aggregate can be specified. The system will then — while an aggregate is assembled in the virtual scene — recognize constructed subassemblies of the target aggregate. Furthermore, if multifunctional parts are used, as is likely when considering standardized construction kits, the system also recognizes the specific functional roles assumed by single parts in different subassemblies. We foresee potential manufacturing applications of virtual assembly (a) in the rapid design of novel assemblies and (b) in planning and simulation of assembly processes.
Tradewind: A Prototype Internet Marketplace for Solid Free-Form Fabrication
Authors: Tan Sian , Rothkopf Alan , Pinilla Miguel
Published: February 2021

TRADEWIND is a prototype electronic marketplace for SFF processes. This marketplace facilitates the interaction between designers and manufacturers from the initial request for bids to build a design up to transaction closure. The system is built with three distinct layers of functionality corresponding to the market functions of presence and accreditation, bid resolution and transaction closure. The bid resolution process collects bids from a number of manufacturing centers and performs a manufacturability analysis to compare a proposed design with the manufacturing capabilities of each of them. To support this manufacturability analysis we present a prototype parametric language to represent the parts to be built and the manufacturing constraints called “ShopTalk”.
Java-Based Tools for Development and Diagnosis of Real-Time Control Systems
Authors: Shackleford Will , Proctor Fredrick M.
Published: February 2021

The National Institute of Standards and Technology (NIST) has been using the Real-time Control System (RCS) Reference Model Architecture for building control systems based on a hierarchy of cyclically executing control modules. This paper describes the work done to build Java tools that allow developers to lay out their hierarchy according to RCS tenets and view or change the inputs and outputs of each module at run-time.
Integrating Virtual Reality for Virtual Prototyping
Authors: Gomes de S. Antonino , Zachmann Gabriel
Published: February 2021

Business process re-engineering is becoming a main focus in today’s efforts to overcome problems and deficits in the automotive and aerospace industries (e.g., integration in international markets, product complexity, increasing number of product variants, reduction in product development time and cost).

In this paper, we investigate the steps needed to apply virtual reality (VR) for virtual prototyping (VP) to verify assembly and maintenance processes. After a review of today’s business process in vehicle prototyping, we discuss CAD-VR data integration and identify new requirements for design quality. We present several new interaction paradigms so that engineers and designers can experiment naturally with the prototype.

Finally, some results of a user survey performed at BMW are presented, showing the acceptance and feasability of VP and the paradigms implemented for our key process. The results show that VR will play an important role for VP in the near future.
Cyberbikes: An Interactive Virtual Environment for the Visualization of Industrial Business Processes
Authors: Gausemeier Jürgen , von Bohuszewicz Oskar , Ebbesmeyer Peter , Grafe Michael
Published: February 2021

This paper describes CYBERBIKES, a real-time simulation of an enterprise that produces bicycles. The system is designed as a virtual environment. It is based on a realistic 3-D model of an industrial enterprise coupled with the representation and control of production processes. Furthermore, the flow of information like production data is visualized by means of clear metaphors. The user is immersed in the virtual environment by using a head mounted display through which he/she can explore the various departments of the industrial enterprise and learn how information technology influences modern production processes. This system is intended to train students of industrial engineering in the workings of a modern industrial enterprise. It will also be used for research in production technology as well as in the practical study of virtual reality technology.
Virtual Prototyping of Xerographic Components
Authors: Rai Sudhendu , Ramesh Palghat S. , Tan Chak
Published: February 2021

This paper describes virtual prototyping in the context of the design of xerographic components in printers and copiers. A design example of a corona charging device, namely a corotron is presented. A first principle physics based numerical model of a charging device is described. A case study is presented in which this proprietary numerical model is seamlessly integrated with a commercial CAD system and used to create a virtual prototype of a corotron. Examples of designing and analyzing different geomteries using this virtual prototype are presented and the benefits of this approach are explained.
GA-Based Fuzzy Neural Network for Adaptive Fuzzy Modeling and Control
Authors: Chen Tongjian , Peng Yonghong , Xie Weiqiang , Deng Hongming
Published: February 2021

Fuzzy logic theory has provided a model-free tool to develop intelligent control system for complex industrial processes by means of simulating the fuzzy reasoning process of human being. However, the performance of such a control system depends on the knowledge base (control rules and membership functions of fuzzy sets). For the control of complex industrial process in which the dynamic parameters of process is time-varying and non-linear, it is necessary to modify and optimize the knowledge base on-line. Adaptive fuzzy control provides a efficient approach for this objective. In this paper, a new fuzzy neural network (FNN) and an adaptive learning mechanism based on genetic algorithm has been proposed for modeling the fuzzy reasoning process and constructing an efficient adaptive fuzzy control systems. Experiment results show that the FNN is capable of modeling complex functions and simulating fuzzy reasoning process of human being.
A Computational Study of the Interaction of Melting Soil With Moisture Transport in the Native Soil
Authors: Schreiber Will , Kuo John
Published: February 2021

The current paper describes a computer model designed to analyze the moisture transport in the unmelted, porous soil neighboring a convecting melt. The time-dependent fluid and heat flow in the soil melt is simulated implicitly using the SIMPLE method generalized to predict viscous fluid motion and heat transfer on boundary-fitted, non-orthogonal coordinates which adapt with time. TOUGH2, a general-purpose computer code for multiphase fluid and heat flow developed by K. Pruess at Lawrence Berkekey Laboratory, has been modified for use on time-adaptive, boundary-fitted coordinates to predict heat transfer, moisture and air transport, and pressure distribution in the porous, unmelted soil. The soil melt model is coupled with the modified TOUGH2 model via an interface (moving boundary) whose shape is determined implicitly with the progression of time.

The computer model’s utility is demonstrated in the present study with a special two-dimensional study. A soil initially at 20°C and partially-saturated with either a 0.2 or 0.5 relative liquid saturation is contained in a box two meters wide by ten meters high with impermeable bottom and sides. The upper surface of the soil is exposed to a 20°C atmosphere to which vapor and air can escape. Computation begins when the soil, which melts at 1700°C, is heated from one side (maintained at constant temperatures ranging from 1700°C to 4000°C). Heat from the hot wall causes the melt to circulate in such a way that the melt interface grows more rapidly at the top of the box than at the bottom. As the upper portion of the melt approaches the impermeable wall it creates a bottle neck for moisture release from the soil’s lower regions. The pressure history of the trapped moisture is examined as a means for predicting the potential for moisture penetration into the melt. The melt’s interface movement and moisture transport in the unmelted, porous soil are also examined.
PAM-OPT™/PAM-SOLID™: Optimization of Transport Vehicle Crash and Safety Design and Forming Processes
Authors: Haug E. , Guyon P.
Published: February 2021

Dynamic simulation solver codes are now extensively used by industry for the design verification of vehicle crashworthiness and for the process simulation of sheet metal forming. The logical next step is to use these by now proven codes for the optimization of the vehicle crash design and of metal forming processes. A step towards this goal has been taken by PSI, and an optimization code, PAM-OPT™, has been written for calling dynamic FE codes of the PAM-SOLID™ family in design and process optimization loops. The code interacts with the user via input, signalling and output files and it calls an interface that interacts with the FE solvers. The paper briefly outlines the properties and various flow charts of the optimizer, depending on single or multiple solvers used in the loop, single or parallel calls and fast solvers. Then the paper reports various applications of PAM-OPT™ in conjunction with the PAM-SFE™, PAM-CRASH™, PAM-SAFE™ and PAM-STAMP™ solvers. An outlook on how to replace the user-written interface with a general keyword-driven interface concludes the paper.
A Decision-Based Approach to Improving Behavior Over Time of Complex Systems
Authors: Bailey Reid , Bras Bert , Allen Janet K.
Published: February 2021

Due to the size and number of interdependencies in a complex system, the resilience of such a system to disturbances is often questionable. In this paper, a case study, an industrial ecosystem in Kalundborg, Denmark, is modeled and investigated with respect to its ability to handle disturbances. Several disturbances are introduced and the robustness through time of production processes to these disturbances is measured and improved with an augmented form of the Robust Concept Exploration Method, in which response surfaces and a multiobjective problem solving tool are utilized. The standard RCEM is augmented to reduce the degree of approximation on which the solution ranges are based. This approach is significantly different from others in that behaviors over time, not instantaneous values, are improved. These behaviors over time are evaluated using multiple time pattern descriptors which characterize relevant features of the behaviors. The simulation model used in this paper is not emphasized as much as the processes used in measuring and improving the behavior over time of a complex system.
A Systematic Topology Optimization Approach for Optimal Stiffener Design
Authors: Luo Jian Hui , Gea Hae Chang
Published: February 2021

A systematic topology optimization approach is developed to design the optimal stiffener of three dimensional shell/plate structures in static and eigenvalue problems. Optimal stiffener design involves the determination of the best location and orientation. In this paper, the stiffener location problem is solved by a microstructure-based design domain method and the orientation probelm is modeled as an optimal orientation problem of equivalent orthotropic materials, which is solved by a newly developed energy based method. Examples are presented to demonstrate the application of the proposed approach.
A Preference-Based Robust Design Metric
Authors: Iyer Harikumar V. , Krishnamurty Sundar
Published: February 2021

Robust optimal design can be studied as a problem in decision-making requiring tradeoffs between mean and variance attributes. In this context, this paper views Taguchi’s philosophy based design metrics using signal-to-noise (SN) ratios as empirical applications of decision-making under uncertainty with a priori sets of attribute tradeoff values. Alternatively, this paper presents a more rigorous preference-based design metric using concepts from utility theory to accurately capture designer’s intent and preferences. The use of this design metric as the robust optimal design criterion in a modified TRED (Tradeoffs in Robust Engineering Design) method with an innovative response-surface based iterative design space reduction strategy is presented. The effectiveness of the overall design procedure and the performance of the preference-based design metric are tested with the aid of demonstrative case studies and the results are discussed.
Assembly Planning: A Genetic Approach
Authors: Chen Shiang-Fong
Published: February 2021

The difficulty of an assembly problem is the inherent complexity of possible solutions. If the most suitable plan is selected after all solutions are found, it will be very time consuming and unrealistic. Motivated by the success of genetic algorithms (GAs) in solving combinatorial and complex problems by examining a small number of possible candidate solutions, GAs are employed to find a near-optimal assembly plan for a general environment. Five genetic operators are used: tree crossover, tree mutation, cut-and-paste, break-and-joint, and reproduction. The fitness function can adapt to different criteria easily. This assembly planner can help an inexperienced technician to find a good solution efficiently. The algorithm has been fully implemented. One example product is given to show the applications and results.
Robust Design Using Fuzzy Numbers
Authors: Arakawa Masao , Yamakawa Hiroshi , Hagiwara Ichiro
Published: February 2021

In this study, we will propose a new method of robust design, which is formulated by using fuzzy numbers as design variables and parameters. In the past robust design methodology, especially by considering usage of optimization, its basic formulations have been done by stochastic optimization. In those cases, they could not handle the deviation in design variables of both sides of shape or their index for their width, because they were mainly based on normal distribution. In this study, we will compare the formulation of fuzzy optimization and stochastic optimization and clarify the characteristics of the proposed method from differences between formulations. Through those comparisons, we will explain the benefit and suitability of the proposed method to robust design in settings of objective functions, treatments of constraints and benefit of design variables which can treat both sides of index for its deviation.
Using the Design Structure Matrix to Estimate Product Development Time
Authors: Carrascosa Maria , Eppinger Steven D. , Whitney Daniel E.
Published: February 2021

This model estimates the probability of completing a product development process over time. The Design Structure Matrix (DSM) framework is used to capture the information dependencies between tasks using the concepts of Probability of Change and Impact. The model incorporates a stochastic element that represents the likelihood of changes resulting in task iterations.

The model captures the dynamic behavior of a product development process formed by a combination of parallel, serial and coupled tasks. The model relaxes the assumption that coupled tasks take place in a complete parallel or serial iteration. It can be used to compare the development time of the project for different task sequences and overlapping degrees. This tool allows for identification of the leverage points in the system, providing information about the most effective way to reduce development time.

This project was a joint effort with a Hewlett-Packard division, and the observations and practical application presented are based on this field experience.
Agent Support for Design Manufacturability
Authors: Jha Krishna N. , Coen Gary , Morris Andrea , Mytych Ed , Spering Judith
Published: February 2021

Designing manufacturable aircraft parts requires satisfying extensive manufacturability constraints early in the design phase, and to quickly propagate the design decisions to the multiple distributed design groups. We have built a multi-agent-based system to provide the desired manufacturability-constraints checking early in the design-process, coordination among the design and analysis groups, the legacy applications, and other resources during the preliminary design (PD) process. A variety of agents are used to model the various design and analysis functionalities. The agent-representation includes a formal representation of the task-structures. One of the agents generates a prototype process plan for the design, and checks the process plan against a repository of processing standards for the manufacturability of the design. A web-based user-interface provides high-level interface to the users. The agents collaborate to produce manufacturable designs.
Concurrent Part and Process Design for Quality Improvement
Authors: Suri Rajiv , Otto Kevin
Published: February 2021

Concurrent part and process design has been shown to reduce product development time and cost. With modeling support it can also lead to improvements in product quality by providing design engineers with an understanding of manufacturing capability, not in terms of nominal constraints, but in terms of variation. In this paper we outline an approach to concurrent design based on a combination of manufacturing process variation models that we call the Integrated System Model (ISM). The ISM can be used to simultaneously choose combinations of design and manufacturing variables that result in minimal variation for the final product. We explore this approach through an example drawn from sheet metal part manufacturing in the aerospace industry.
Reliability Analysis of Repairable Systems Subject to System Modifications
Authors: Jiang Z. H. , Shu L. H. , Benhabib B.
Published: February 2021

This paper approaches environmentally conscious design by further developing a reliability model that facilitates design for reuse. Many reliability models are not suitable for describing systems that undergo repairs performed during remanufacture and maintenance because the models do not allow the possibility of system reconfiguration. In this paper, expressions of reliability indices of a model that allows system reconfiguration are developed to enable life-cycle cost estimation for repairable systems. These reliability indices of a population of repairable systems are proven theoretically to reach steady state. The expressions of these indices at steady state are obtained to gain insight into the model behavior, and to facilitate life-cycle cost estimation.
ISO 14000 and Activity-Based Life-Cycle Assessment in Environmentally Conscious Design and Manufacturing: A Comparison
Authors: Emblemsvåg Jan , Bras Bert
Published: February 2021

As a part of the new ISO 14000 environmental management standard, standards for conducting Life-Cycle Assessments (LCAs) are proposed. In this paper we compare these standards to Activity-Based LCA by using a toy manufacturer called WagonHo!, Inc. as an implementation test case. In this case study, both economical and environmental assessments are made of the product- and process designs. Because the ISO 14000 LCA does not incorporate costing methods, we have used Variable Costing combined with standard times. Activity-Based LCA, on the other hand, combines an Activity-Based Costing (ABC) like method and activity-based environmental impact assessment methods into a single method. The ISO 14000 and Activity-Based LCA are compared with respect to assessment accuracy and how well they indicate areas in need of redesign. Due to the need of short-term survival caused by a severe negative economic result, we will mainly look at process design and market strategies, because product design is a more long-term effort. It is shown that in this case, Activity-Based LCA is superior to ISO 14000 based LCA — possibly in most situations.
Design of an Isotropic Compliance Mechanism for Off-Axis Peg-in-Hole Insertion
Authors: Sathirakul Korntham , Sturges Robert H.
Published: February 2021

Assembly sequences may require part grasp poses that differ from the implicit assembly insertion axis of RCC-type devices. Since favorable compliant responses accrue only for the insertion axis engineered into the RCC, such “off-axis” poses may obviate its use. The fundamental issue is the creation of an effective compliance that is isotropic in a plane normal to the insertion axis, irrespective of the location of the mechanism. This paper addresses the design of alternative compliant devices, especially an RRR spherical mechanism suitable for industrial application. General compliance requirements are established, mechanism kinematics are developed, and design equations are presented. A laboratory model is described that embodies the desireable features of zero friction, zero backlash, and isotropic stiffness for off-axis assembly tasks.
What Is a Manufacturing Interaction?
Authors: Faheem W. , Hayes C. C. , Castaño J. F. , Gaines D. M.
Published: February 2021

In this work we make a distinction between feature interactions and manufacturing interactions. These two terms are usually used interchangeably because feature and manufacturing interactions often occur together, but not always. However, we feel that it is important to make a distinction between feature interactions which result from volumetric intersections of features presenting difficulties for features extractors, and manufacturing interactions which occur when two manufacturing operations interfere with each other’s execution, and present a problem to the process planner. By separating these definitions it allows us to focus separately on each phenomena. In this paper our focus is on manufacturing interactions. We present a non-exhaustive catalog of common manufacturing interaction types in CNC machining, and discuss how they result in precedence constraints in the manufacturing plan.
Double Quaternions for Motion Interpolation
Authors: Ge Q. J. , Varshney Amitabh , Menon Jai P. , Chang Chu-Fei
Published: February 2021

This paper describes the concept of double quaternions, an extension of quaternions, and shows how they can be used for effective three-dimensional motion interpolation. Motion interpolation using double quaternions has several advantages over the method of interpolating rotation and translation independently and then combining the results. First, double quaternions provide a conceptual framework that allows one to handle rotational and translational components in a unified manner. Second, results obtained by using double quaternions are coordinate frame invariant. Third, double quaternions allow a natural way to tradeoff robustness against accuracy. Fourth, double quaternions, being a straightforward extension of quaternions, can be integrated into several existing systems that currently use quaternions with translational components, with a only small coding effort.
Spatial Incompatibility: Part Interaction and Tolerance Allocation in Configuration Design
Authors: Söderberg Rikard , Johannesson Hans L.
Published: February 2021

This paper describes how function-means modeling techniques and spatial coupling analysis can be used in early design stages to increase robustness and knowledge about geometrical sensitivity of an assembly design. By incorporating spatial constraint decomposition in function-means modeling, overall spatial constraints may be broken down into nominal dimensions and tolerances for geometrical features. The analysis is carried out at the very early design stages, before CAD models are created and when only simple sketches exist. By documenting all information about functional requirements, design parameters and constraints in a hierarchically decomposed function-means structure, spatial couplings and overall sensitivities may be detected and alternative, less sensitive, concept solutions may be developed. Analyses of functional and constraint couplings increases the knowledge of and understanding for the geometrical sensitivity of a complex assembly design. This knowledge and understanding then serves as a base for tolerance allocation, where tolerances are to be allocated in the most functional and cost effective way.
Preliminary Vehicle Structure Design: An Industrial Application of Imprecision in Engineering Design
Authors: Scott Michael J. , Antonsson Erik K.
Published: February 2021

The Method of Imprecision, or MoI, is a formal method for incorporating imprecise information into a design process. This methodology has been exercised on a problem in preliminary vehicle structure design in collaboration with VW Wolfsburg. Results show that the method is useful in trading off multiple conflicting attributes, including styling preferences and engineering requirements.
A Process Management Strategy for Re-Design: An Anchoring Adjustment Approach
Authors: Dixon Lisa A. , Colton Jonathan S.
Published: February 2021

Preceding research on the re-design process focused on the development and verification of an Anchoring and Adjustment design process model. Compared to the existing, predominantly top-down, models, this new model was tailored specifically to describe designers’ approaches to re-design tasks. Building upon that work, this paper presents an evaluation of a re-design process strategy that is based on the key elements identified in the Anchoring and Adjustment model (a general pattern for re-design activities and two evaluation metrics). The overall goal was to formulate an efficient and effective process management strategy unique to re-design activities. Data were collected from three industry re-design projects for the evaluation. First, an analysis of the data confirmed that the pattern of design activities and evaluation metrics used by the company’s designers could be mapped onto those that comprise the Anchoring and Adjustment model. Second, the analysis of the data suggested that with additional formalization — based on an anchoring and adjustment approach — the company’s current process management technique could provide more accurate feedback to the designers for the more efficient and effective management of their re-design processes. One of the industry case studies is detailed to illustrate the research results and conclusions.
On the Applicability of Product Variety Design Concepts to Automotive Platform Commonality
Authors: Siddique Zahed , Rosen David W. , Wang Nanxin
Published: February 2021

The issue of moving from a mass production operating mode to mass customization, or even limited customization, has many companies struggling to reorganize their product architectures. Enabling the production of several related products for different market segments, from a common base, is the focus of the product variety design research area. In this paper, the applicability of product variety design concepts to the design of automotive platforms is explored. Many automotive companies are reducing the number of platforms they utilize across their entire range of cars and trucks in an attempt to reduce development times and costs. To what extent can research on product variety design apply to the problem of platform commonization? This question is explored by comparing product variety design concepts (standardization, modularity, mutability, etc.) to platform structures and requirements. After assessing the applicability of these concepts, a platform representation and methods for measuring platform commonality are proposed that incorporate key characteristics of these concepts. An application to two platforms is included. Although preliminary, this work has led to insight as to why automotive platform commonization is difficult and how product design variety research can potentially aid commonization. The findings are potentially applicable to product platforms in general.
An Overview of Inference Mechanisms for Quantified Relations
Authors: Finch William W.
Published: February 2021

This paper temporarily sheds formal mathematical treatment and presents a more intuitive overview of inference mechanisms for quantified relations. These predicate logic expressions are a new class of design constraint among sets of variations affecting the design and performance of engineering systems. Simple examples illustrate the use of quantified relations to infer constraints on the membership of feasible sets. A small design problem from the electronics domain joins the mathematical tools with engineering concepts. A brief comparison demonstrates the advantages of this approach over conventional interval mathematics. This paper’s objective is to illustrate the application of quantified relations and their associated methods to engineering design problems.
A Graph Grammar Approach for Structure Synthesis of Mechanisms
Authors: Schmidt Linda C. , Shetty Harshawardhan , Chase Scott C.
Published: February 2021

This paper presents a general graph grammar for structure synthesis of mechanisms. Much of current mechanism design is based on a systematic method popularized by Freudenstein, Buchsbaum, Mruthyunjaya and Tsai (among others). Since it relies on algebraic abstractions of graph theoretic principles, a graph grammar is a more natural expression for the method. Our proposed mechanism grammar rules add vertices and loops to a start graph to obtain desired structural requirements. A specialized grammar for the structure synthesis of Epicyclic Gear Trains is presented. As is a grammar adaptation of an existing linear time algorithm for the detection of isomorphism. A valid graph grammar for structure synthesis of mechanisms enables the eventual automation of general atlas construction and atlas construction for specialized mechanism classes.
A Knowledge-Based Engineering (KBE) Graduate Design Class
Authors: Calkins D. E. , Egging Nathaniel , Scholz Christian
Published: February 2021

An emerging technology known as Knowledge-Based Engineering (KBE) is the next step beyond CAD for product representation. KBE allows a true virtual prototype to be developed that represents both the geometric and the non-geometric characteristics of a product. A graduate level design course based on this technology is described. A new version of the design process is presented for the development of a virtual prototype. Examples of a product that was modeled, a hand held vacuum, are also presented.
Supporting Product Development With Innovative Technologies and Methods
Authors: Döllner Gernot , Tegel Oliver
Published: February 2021

In this paper, we discuss the two different innovative tools, Digital Mock-Ups and Rapid Prototyping, and their key features. To make sure that their use is adapted to the needs of the company, different aspects of implementation in industrial practice are discussed.
A Passive Compliant Wrist Design for Robot Manipulators
Authors: Hoffman Christopher D. , Soni A. H. , Thompson David F.
Published: February 2021

Robot assembly in manufacturing systems is still a work-intensive process. A main difficulty that arises when trying to automate an assembly task with a robot is the precision required to position and orient the parts. This difficulty arises in several sources of error, such as robot accuracy, the gripping and presentation precision of pieces, and part tolerance. High requirements for part insertion also present a greater possibility for jamming of parts and bottlenecking of the assembly line. Using a compliant device mounted between the end effector of the robot and the gripper mechanism may relieve this situation.

In order to achieve the reality of cheaper automation solutions by using robots in high precision insertion tasks, a passive compliant gripper device would need to be used. A passive design would supply the user with a “bolt-on” device that did not require any extra controllers or interfacing between the compliant wrist and the robot main controller, as is the case with an active or hybrid design. Using the wrist in operation, the number of damaged parts and the number of crashes by the robot would be reduced. Other compliant devices that are currently offered by commercial companies are compared with the proposed design and debated.

After a study of existing compliant devices, a novel approach is presented. Utilizing an earthquake protection device for buildings as an initial idea fountain, a new compliant wrist design is formulated. The Passive Compliant Wrist design, based on a building support system, is exhibited in detail. A comprehensive discussion of the wrist in operation is also presented. The final design has also been verified using the dynamic motion simulation program, Working Model, by Knowledge Revolution.
The Design of a Novel Mechanical Transmission for Speed Reduction
Authors: González-Palacios Max A. , Angeles Jorge
Published: February 2021

The design of a novel transmission for speed reduction is reported in this paper. The transmission is based on the layout of pure-rolling indexing cam mechanisms, and hence, eliminates backlash and friction, which are the main drawbacks of gear transmissions. The design relies on a unified methodology for indexing cam mechanisms, whereby the same procedure is used to design planar, spherical, and spatial mechanisms. Two versions of the speed reducer, that we term Speed-o-Cam, are described here, namely, planar, to couple shafts of parallel axes, and spherical, to couple shafts of intersecting axes. By means of a cascade of two planar versions of Speed-o-Cam, moreover, coaxial shafts can be coupled. The proposed design thus eliminates the drawbacks of gear transmissions without bringing about those of harmonic drives or epicyclic transmissions, which nevertheless work only for coaxial shafts.
Determination of Follower Motions Using Measured Cam Profiles
Authors: Tsay Der Min , Huang Meng Hung , Ho Hui Chun
Published: February 2021

A versatile, systematic procedure that can be used to determine follower motions from measured discrete planar cam profile data is presented. Based on the geometric relationship at the contact point between a cam and its follower system, the reverse functions for planar cams with various types of followers are established. Then, a periodic B-spline approximation in a form of least squares is introduced to approximate the measured data and to generate the data derivatives required in finding their corresponding follower motions. The accuracy and reliability of this method is verified, and furthermore, a practical example is given to show the application of this procedure.
Design and Control of a Compliant Parallel Manipulator for a Mobile Platform
Authors: Sugar Thomas , Kumar Vijay
Published: February 2021

We describe a novel design for a compliant arm that can be mounted on a mobile robot. The main features of the arm are the in-parallel architecture of the arm and a novel control scheme that allows us to easily control the Cartesian stiffness or impedance in the plane.

Because the arm is compliant, a mobile robot can manipulate or interact with objects that are not precisely positioned in the environment. Further, a mobile robot equipped with such an arm can cooperate with other mobile robots in manipulation tasks. For example, two such arms can hold an object in a stable grasp by applying and maintaining appropriate contact forces with the appropriate stiffness. We present experimental results that show the performance of the compliant arm and the use of the arm while two platforms cooperate in a manipulation task.
Analytical Foundations for Modeling Interactions in Dynamic Systems Based on Impulsive Constraints
Authors: Kövecses J. , Cleghorn W. L. , Fenton R. G.
Published: February 2021

In this paper we outline the analytical foundations of an approach for modeling interactions in dynamic systems. The method is based on impulsive constraints which can be employed to represent time-varying interaction of dynamic subsystems, and the transition between different phases of motion. Besides impulsive constraints, the analysis is based on Jourdain’s principle, and a kinematic representation of constrained mechanical systems which is related to this principle. Both finite and impulsive constraints are considered in a general manner, assuming that those can be nonlinear in velocities. It will be shown that Jourdain’s principle can create a simple and physically clear basis for such constrained motion problems. A classification of motions constrained by finite or impulsive constraints is discussed. An impulse-momentum level form of Jourdain’s principle is presented to handle impulsive constraints. An example of two robotic arms in cooperation is employed to illustrate the material presented.
Dual Properties for Vibration Analysis via Screw Theory
Authors: Blanchet Pat , Lipkin Harvey
Published: February 2021

Recent discoveries about the structure of stiffness and inertia are combined to analyze free linear vibrations. It is shown that the dual to a pure translation mode is a pure couple mode. The analysis is performed for the general case and then specialized to more simple problems. The results also develop the conditions for the existence of pure translation and couple modes. Examples illustrate the results.
A Comparative Study on Some Modular Approaches for Analysis and Synthesis of Planar Linkages: Part I — Modular Structural Analysis and Modular Kinemaic Analysis
Authors: Yang Ting-Li , Yao Fang-Hua , Zhang Ming
Published: February 2021

This paper presents a systematical comparative study of various modular methods based on the different module types: basic kinematic chains (BKCs), single opened chains (SOCs), loops (or a tree and co-tree), links-joints, etc. for analysis and synthesis of structure, kinematics and dynamics of planar linkages. The basic idea is that any linkage can be divided into (or built up by) some modular components in sequence, and based on the component constraints and network entirty constraints of the linkage, the unified modular approaches have been used for analysis and synthesis. In the systematical comparative study, the main issues of a modular method have been discussed, such as: the topological characteristics revealed via different module types; the dimension of a set of kinematic equations; the automated generation and solution of kinematic equations; the dimension and automated generation of dynamical equations, and computation complexity for generating and solving dynamical equation; the automated generation of structural analysis and type synthesis; the generation of kinematic synthesis equations etc.. This paper gives a summary of the use of modular techniques for analyzing and synthesizing planar linkages in the recently thirty years. This comparative study includes two parts: part I — modular structural analysis and modular kinematic analysis; part II — modular dynamics analysis, modular structural synthesis and modular kinematic synthesis. This paper is the first part.
Compliant Pantographs via the Pseudo-Rigid-Body Model
Authors: Nielson Andrew J. , Howell Larry L.
Published: February 2021

This paper uses a familiar classical mechanism, the pantograph, to demonstrate the utility of the pseudo-rigid-body model in the design of compliant mechanisms to replace rigid-link mechanisms, and to illustrate the advantages and limitations of the resulting compliant mechanisms. To demonstrate the increase in design flexibility, three different compliant mechanism configurations were developed for a single corresponding rigid-link mechanism. The rigid-link pantograph consisted of six links and seven joints, while the corresponding compliant mechanisms had no more than two links and three joints (a reduction of at least four links and four joints). A fourth compliant pantograph, corresponding to a rhomboid pantograph, was also designed and tested. The test results showed that the pseudo-rigid-body model predictions were accurate over a large range, and the mechanisms had displacement characteristics of rigid-link mechanisms in that range. The limitations of the compliant mechanisms included reduced range compared to their rigid-link counterparts. Also, the force-deflection characteristics were predicted by the pseudo-rigid-body model, but they did not resemble those for a rigid-link pantograph because of the energy storage in the flexible segments.
Identification and Compensation of Geometric and Elastic Errors in Large Manipulators: Application to a High Accuracy Medical Robot
Authors: Meggiolaro Marco A. , Mavroidis Constantinos , Dubowsky Steven
Published: February 2021

A method is presented to identify the source of end-effector positioning errors in large manipulators using experimentally measured data. Both errors due to manufacturing tolerances and other geometric errors and elastic structural deformations are identified. These error sources are used to predict, and compensate for, the end-point errors as a function of configuration and measured forces. The method is applied to a new large high accuracy medical robot. Experimental results show that the method is able to effectively correct for the errors in the system.
Static Balancing of Spatial Six-Degree-of-Freedom Parallel Mechanisms With Revolute Actuators
Authors: Wang Jiegao , Gosselin Clément M.
Published: February 2021

The static balancing of spatial six-degree-of-freedom parallel mechanisms or manipulators with revolute actuators is studied in this paper. Two static balancing methods, namely, using counterweights and using springs, are used. The first method leads to mechanisms with a stationary global center of mass while the second approach leads to mechanisms whose total potential energy (including the elastic potential energy stored in the springs as well as the gravitational potential energy) is constant. The position vector of the global center of mass and the total potential energy of the manipulator are first expressed as functions of the position and orientation of the platform. Then, conditions for static balancing are derived from the resulting expressions. Finally, examples are given in order to illustrate the design methodologies.