bluuebunny/crossref_metadata_2025 huggingface dataset:
Recent Advancements in Product Family Design and Platform-Based Product Development: A Literature Review
Authors: Pirmoradi Zhila , Wang G. Gary
Published: June 2012

Increase of demand on product variety has pushed companies to think about offering more and more product variants in order to take more market shares. However, product variation can lead to cost increase for design and production, as well as the lead time for new variants. As a result, a proper tradeoff is required between cost-effectiveness of manufacturing and satisfying diverse demands. Such tradeoff has been shown to be manageable effectively by exploiting product family design (PFD) and platform-based product development. These strategies have been widely studied during the past decades, and a large number of approaches have been proposed for covering different issues and steps related to design and development of product families and platforms. Verification and performance of such approaches have also been traced through practical case studies applied to several industries. This paper focuses on a review of the research in this field and efforts to classify the recent advancements relevant to product family design and platform development issues. A comprehensive review on the state-of-the-art research in this field was done by Jiao et al. in 2007; therefore the main focus of this paper is on the research activities from 2006 to present. Mainly, the effort of this paper is to identify new achievements in regard with different aspects of product family design such as customer involvement in design, market driven studies, new indices and metrics for assessing families and developing the desired platforms, issues relevant to product family optimization (i.e., new algorithms and optimization approaches applied to different PFD problems along with their benefits and limitations in comparison to previously developed approaches), issues relevant to development of platforms (i.e., platform configuration approaches, joint platform design and optimization, and factors effective on forming proper platform types), and issues relevant to knowledge management and modeling of families and platforms for facilitating and supporting future design efforts. Through a comparison with previous research, new achievements are discussed and the remaining challenges and potential new research areas in this field are addressed.
On the Accuracy of Assumed Mode Modeling for Flexible Manipulators
Authors: Heidari F. , Vakil M. , Fotouhi R.
Published: June 2012

Assumed mode shape method (AMM) has been widely used to derive finite degree-of-freedom (DOF) dynamic model for flexible link manipulators, which theoretically have infinite DOF dynamics. For single flexible manipulator, this approximation changes locations of the zeros of transfer function, between base torque and end-effector displacement. The change in locations of zeros considerably affects accuracy of the model and hence the performance of model-based controllers. This paper presents a comprehensive study on the change in location of zeros due to the truncation associated with AMM. It is shown that the locations of zeros of AMM model depend on four non-dimensional parameters while the locations of the analytical model depend on only two non-dimensional parameters; AMM zeros are obtained from AMM model while analytical zeros derived from infinite order model. A thorough study on the differences between AMM zeros and analytical zeros versus number of mode shapes as well as all the physical parameters is performed. Moreover, guidelines are provided to select the numbers of mode shapes such that the AMM zeros become close to the analytical zeros. These guidelines can easily be used by control engineers and thus makes them valuable for modeling and control of flexible robot manipulators.
Multi-Relationship Evaluation Design: Formalizing Test Plan Input and Output Elements for Evaluating Developing Intelligent Systems
Authors: Weiss Brian A. , Schmidt Linda C.
Published: June 2012

Advanced and intelligent systems within the manufacturing, military, homeland security, and automotive fields are constantly under development or improvement. Testing the performance of these technologies is critical to (1) notify the system designers of specific areas for improvement, (2) solicit end-user feedback, and (3) validate the extent of a technology’s capabilities. Evaluation designers have expended considerable effort in devising methodologies to stream-line the development of test plans in support of performance evaluation. The Multi-Relationship Evaluation Design (MRED) methodology is being developed to take multiple inputs from numerous input source categories and automatically output evaluation blueprints that specify the test characteristics. The MRED methodology is being created to have numerous advantages over current test design methods including 1) creating test plans to appraise both quantitative and qualitative performance of technologies that incorporate both human-controlled and autonomous capabilities, 2) speeding the test plan and implementation cycle to improve the effectiveness of a technology’s development cycle, and 3) factor in unknown and uncertain test plan input data. This paper will present the following: the MRED model will be discussed; detailed definitions and relevant relationships of the stakeholder input category will be presented; the output test plan element of evaluation personnel will be defined and their constraints discussed; the stakeholders’ influence on determining the selecting evaluation personnel will be presented including its initial formulation; and several examples of this cause (stakeholder preferences) and effect (evaluation personnel selection) relationship will be highlighted in two unique technology test plans.
Advanced System Identification of Plates Using a Higher-Order-Spectral Approach: Theory and Experiment
Authors: Pasquali Michele , Lacarbonara Walter , Marzocca Pier
Published: June 2012

A nonlinear system identification technique exploiting the dynamic response features of fully nonlinear physics-based plate models extracted by Higher-Order Spectral (HOS) analysis tools is developed. The changes induced by an imperfection in the dynamics through the structural nonlinearities are used as key detection mechanism. The differences in dynamic response of a baseline and a modified/imperfect structure are enhanced by the local nonlinearities induced by the structural modification which thus represent the specific objective of identification. The validation of the procedure and the developed algorithms is carried out through extensive experimental testing employing various plates, including isotropic and composite lay-ups, and excitation sources, including White Gaussian Noise and a train of impulses.
Shape Design of Periodic Cellular Materials Under Cyclic Loading
Authors: Masoumi Khalil Abad Ehsan , Arabnejad Khanoki Sajad , Pasini Damiano
Published: June 2012

This paper presents a method to improve the fatigue strength of 2D periodic cellular materials under a fully-reversed loading condition. For a given cell topology, the shape of the unit cell is synthesized to minimize any stress concentration caused by discontinuities in the cell geometry. We propose to reduce abrupt geometric changes emerging in the periodic microstructure through the synthesis of a cell shape defined by curved boundaries with continuous curvature, i.e. G2-continous curves. The bending moments caused by curved cell elements are reduced by minimizing the curvature of G2-continuous cell elements so as to make them as straight as possible. The asymptotic homogenization technique is used to obtain the homogenized stiffness matrix and the fatigue strength of the synthesized cellular material. The proposed methodology is applied to synthesize a unit cell topology described by smooth boundary curves. Numeric simulations are performed to compare the performance of the synthesized cellular solid with that of common two dimensional lattice materials having hexagonal, circular, square, and Kagome shape of the unit cell. The results show that the methodology enables to obtain a cellular material with improved fatigue strength. Finally, a parametric study is performed to examine the effect of different geometric parameters on the performance of the proposed cellular geometries.
Manufacturing Footprint Computation From Detailed Machining Plans for Sustainability Assessment in Manufacturing Enterprises
Authors: Turaga Ananth K. , Roy Utpal
Published: June 2012

Several of the currently available engineering design and software analysis packages are being utilized by designers in the early stages of the product life cycle for product modeling and evaluation. However, while the growing need for designing ‘sustainable’ products is increasingly being recognized, an overall lack of measurement tools and formal methods for sustainability assessment remains a void to be addressed. In order to provide a reliable and design-based evaluation approach, “product footprint” is proposed as a viable sustainability assessment metric for gauging the environmental impacts of products. Such an assessment system would give direct feedback to designers of the overall manufacturing impact, so that design modifications can be effected to minimize environmental costs while maintaining product quality and design intent. Further, since all the product structure information is needed throughout the entire product life cycle, the system must be capable of making such evaluations in a PLM environment. A methodology for computing an energy metric and thereby overall manufacturing footprint for sustainability assessment is developed using the Pro/ENGINEER CAD system for design and Pro/NC-MILL for detailed NC path planning for machining operations.
Optimization of Honeycomb Cellular Meso-Structures for High Speed Impact Energy Absorption
Authors: Schultz Jesse , Griese David , Shankar Prabhu , Summers Joshua D. , Ju Jaehyung , Thompson Lonny
Published: June 2012

This paper presents the energy absorption properties of hexagonal honeycomb structures of varying cellular geometries to high speed in-plane impact. While the impact responses in terms of energy absorption and densification strains have been extensively researched and reported, a gap is identified in the generalization of honeycombs with controlled and varying geometric parameters. This paper attempts to address this gap through a series of finite element (FE) simulations where cell angle and angled wall thickness are varied while maintaining a constant mass of the honeycomb structure. A randomly filled, non-repeating Design of Experiments (DOE) is generated to determine the effects of these geometric parameters on the output of energy absorbed, and a statistical sensitivity analysis is used to determine the parameters significant for optimization. A high degree of variation in the impact response of varying cellular geometries has shown the potential for the forward design into lightweight crushing regions in many applications, particularly the automotive and aerospace industries. It is found that while an increase in angled wall thickness enhances the energy absorption of the structure, increases in either the cell angle or ratio of cell angle to angled wall thickness have adverse effects on the output. Finally, optimization results present that a slightly auxetic cellular geometry with maximum angled wall thickness provides for maximum energy absorption, which is verified with an 8% error when compared to a final FE simulation.
Comprehensive Reduced-Order Models of Electrostatically Actuated Curved MEMS Switches and Their Dynamics Including Impact and Bounce
Authors: Snow Michael G. , Bajaj Anil K.
Published: June 2012

As Micro and Nano Electro-Mechanical devices continue to find more applications, the electrostatically actuated micro-beam remains one of the most frequently used structures due to its usefulness and relative simplicity of fabrication. Accurate models of these devices which are valid under a wide range of circumstances are important both for design as well as metrology efforts. Often certain device parameters are implicitly extracted via a mathematical model when they are very difficult to measure directly. This work details the development and results of a reduced-order model for the behavior of an electrostatically actuated beam. The model accounts for arbitrary initial curvature, residual stress, flexible boundary conditions and contact, while including accurate sub-models for the electrostatic and damping forces. The equation of motion of the beam is discretized via the traditional Galerkin method. Static and dynamic solutions are found through specified displacement schemes and direct time integration, respectively. The rich behavior of these systems can easily be seen in the results. Arched doubly-clamped beams can show a variety of bi-stable configurations and tri-stable solutions can be seen in the post-contact behavior of cantilever beams. Dynamic solutions reveal phenomena such as dynamic pull-in, dynamic snap-through, and bouncing behavior. The widely valid model presented here generally converges quickly and is well suited for design, analysis and uncertainty quantification.
Mobility Analysis of Flexure Mechanisms via Screw Algebra
Authors: Su Hai-Jun
Published: June 2012

This paper presents a general framework for studying the mobility of flexure mechanisms with an arbitrary topology using screw algebra. The current approach for mobility analysis of flexures is ad hoc and mostly done by intuition. In this methodology, we first build a library of commonly used flexure elements, flexure joints and simple chains. We then apply the screw algebra to find their motion and constraint spaces in the form of twist and wrench matrices. To analyze a general flexure mechanism, we first apply a top-down approach to hierarchically subdivide it into multiple modules or building blocks down to the level of flexure structures that are already provided in the library. We then use a bottom-up routine to study the mobility of each module up to the level of the overall mechanism. Extensive examples and case studies from simple flexure joints, chains to spatial compliant platforms are used to demonstrate the methodology. This systematic methodology is an important tool for guiding the early stages in flexure mechanism design.
Comparison of Numerical Methods for Determining Torsion Stiffness of Automotive Chassis
Authors: Tebby Steven , Esmailzadeh Ebrahim , Barari Ahmad
Published: June 2012

The torsion stiffness of an automotive chassis can be determined using an analytical approach based purely on geometry, using an experimental method, or alternatively by employing a Finite Element Analysis (FEA) process. These three methods are suitable at different design stages and combined together could prove to be practical methods of determining the torsion stiffness of a chassis. This paper describes and compares two distinct FEA processes to determine the torsion stiffness of an automotive chassis during the detailed design stage. The first process iteratively applies forces to the model and records displacements, while the second process gradually applies vertical displacements in place of force to determine the torsional stiffness threshold. Each method is explained and supported with a case study to provide a basis of comparison of the results.
Finite Element Modeling of a Microdroplet Generator With Integrated Sensing
Authors: Rone William S. , Ben-Tzvi Pinhas
Published: June 2012

This paper describes the analysis of a novel microdroplet generator’s integrated sensing capability using finite element simulation. The dominant paradigm for utilizing droplet generation is with either open-loop or externally-sensed closed-loop methods, each with significant disadvantages in terms of reliability and large-scale implementation, respectively. This work utilizes a system designed with a compressible gas reservoir adjacent to the incompressible droplet liquid reservoir. The compressible gas pressure changes as liquid droplets are dispensed from the constant volume fluid reservoir. This change was found to be linearly dependent on the size of the droplet that was ejected, validating this gas reservoir pressure as a useful means of indirectly measuring droplet size internally within the system.
A Socially Assistive Robot That Can Interpret Body Language
Authors: McColl Derek , Nejat Goldie
Published: June 2012

Socially assistive robots can engage in assistive human-robot interactions (HRI) by providing rehabilitation of cognitive, social, and physical abilities after a stroke, accident or diagnosis of a social, developmental or cognitive disorder. However, there are a number of research issues that need to be addressed in order to design such robots. In this paper, we address one main challenge in the development of intelligent socially assistive robots: A robot’s ability to identify human non-verbal communication during assistive interactions. In this paper, we present a unique non-contact automated sensory-based approach for identification and categorization of human upper body language in determining how accessible a person is to a robot during natural real-time HRI. This classification will allow a robot to effectively determine its own reactive task-driven behavior during assistive interactions. The types of interactions envisioned include providing reminders, health monitoring, and social and cognitive therapies. Preliminary experiments show the potential of integrating the proposed body language recognition and classification technique into socially assistive robotic systems partaking in HRI scenarios.
A Service Structural Analysis Based on Functional Dependency
Authors: Kimita Koji , Hosono Shigeru , Shimomura Yoshiki
Published: June 2012

In manufacturing, systems that offer products in combination with services have attracted considerable attention. According to this background, the authors of this paper have conducted conceptual research on design services from the viewpoint of engineering. This series of research is called “Service Engineering [1–3].” In order to achieve a successful service, various types of stakeholders must be involved. In addition, these stakeholders have to cope with dynamic changes in market, customer demands and so forth. Addressing these changes requires much more complex interactions among relevant stakeholders. To solve this problem, defining service architecture is one of the important decisions. Especially, the modularization of service architecture is defined as one of the key principles. This study, therefore, aims to propose a concrete methodology for determining service modules.
Tip-Tilt Motion Control of Fast Steering Mirror in the Giant Magellan Telescope (GMT)
Authors: Lee Taekyung , Ahn Hyo-Sung , Kim Young-Soo , Park Kwijong
Published: June 2012

This paper develops a tip-tilt motion controller of fast steering mirror (FSM) in the Giant Magellan telescope (GMT). A mathematical model of tip-tilt motion system of FSM is derived, and then based on this model, stability analysis is carried out. A heuristic adaptive controller is designed for the tip-tilt motion control with modeling error. The heuristic controller consists of two different adaptations such as initial adaptive control and adaptation at steady state errors. Through numerical simulations, the validity of the controller is illustrated. After that this paper addresses several practical issues like disturbance from wind, actuator saturation and resonance frequency from mechanical structure in implementing the controller to the actual system.
Ground Antenna Scheduling Algorithm for Multi-Satellite Tracking
Authors: Yun Sang-Hyuk , Ahn Hyo-Sung , Park Sun-Ju , Jung Ok-Chul , Chung Dae-Won
Published: June 2012

In this paper, we address the optimal ground antenna scheduling problem for multiple satellites when multiple satellites have visibility conflicts at a ground station. Visibility conflict occurs when multiple satellites have either overlapping visibilities at a ground station or difference with time of loss of signal (LOS) of a satellite and time of acquisition of signal (AOS) of another satellite is less than reconfiguration time of ground station. Each satellite has a priority value that is a weight function with various factors. Multi-antenna scheduling (MAS) algorithm 1 and Multi-antenna scheduling (MAS) algorithm 2 are proposed to find the optimal schedule of multi-antenna at a ground station using pre-assigned priority values of satellites. We use the depth first search (DFS) method to search the optimal schedule in MAS algorithm 1 and MAS algorithm 2. Through the simulations, we confirm the efficiency of these algorithms by comparing with greedy algorithm.
Analytical Solutions for Oscillation of Rectangular Plate on a Nonlinear Winkler Foundation
Authors: Younesian Davood , Askari Hassan , Saadatnia Zia , Esmailzadeh Ebrahim
Published: June 2012

In this paper the closed form expressions for the dynamic response of an elastic plate rested on a nonlinear elastic foundation are obtained. The nonlinear governing equation is solved using both the Variational Iteration Method (VIM) and the Homotopy Analysis Method (HAM). The frequency responses are presented in the closed form and their sensitivity analyses with respect to their initial amplitudes are investigated. A number of numerical simulations are then carried out and the performance and validity of the solution procedure is evaluated in the time domain. It is proved that the both VIM and HAM are quite reliable and straightforward techniques to solve the corresponding set of nonlinear differential equations and also capable of obtaining the main harmonics of the system.
A Validation Regarding Effectiveness of Scenario Graph
Authors: Yagita Hiroyuki , Tose Akira , Nakajima Madoka , Kim Sun K. , Maeno Takashi
Published: June 2012

Scenario Graph is a structured mind mapping methodology that aids design teams to generate potential scenarios for new products and services while visually organizing contextual information. Since its introduction in industry and academia, the Scenario Graph has helped design teams to capture new values and behaviors of potential customers during the problem formulation stage. At the same time, the Scenario Graph, sharing a common challenge with various design methods, has faced difficulty regarding validation of its effectiveness as a design method. This paper describes a validation framework for a method in problem formulation stages and an experiment, which compare ideation results of 87 people — 43 people with the Scenario Graph method (as a test group) and 44 people with the Brainstorming (as a control group) — to solve an identical problem. While the results show no statistically significant difference in the number of ideas generated, the data reveals statistically significant differences in the quality of ideas. The test group, which used the Scenario Graph, yielded ideas that were more novel, feasible, and abstract than the control group, which used the Brainstorming, did. These metrics represent a way to measure the quality of ideas in the domain of engineering design. Our experiment confirms the hypotheses that the Scenario Graph is effective in improving the performance of idea generation sessions, which is consistent with qualitative evaluations. The lessons, gained from this experiment, provide an insight on how this method can be effectively used during the early stages of concept generation of a company’s process for product and/or service development.
Three Dimensional Vibration Analysis of Rectangular Plates With Undamaged and Damaged Boundaries by the Spectral Collocation Method
Authors: Sari Ma’en S. , Butcher Eric A.
Published: June 2012

This paper presents a new numerical technique for the free vibration analysis of isotropic three dimensional elastic plates with damaged boundaries. In the study, it is assumed that the plates have free lateral surfaces, and two opposite simply supported edges, while the other edges could be clamped, simply supported or free. For this purpose, the Chebyshev collocation method is applied to obtain the natural frequencies of three dimensional plates with damaged clamped boundary conditions, where the governing equations and boundary conditions are discretized by the presented method and put into matrix vector form. The damaged boundaries are represented by distributed translational springs. In the present study the boundary conditions are coupled with the governing equation to obtain the eigenvalue problem. Convergence studies are carried out to determine the sufficient number of grid points used. First, the results obtained for the undamaged plates are verified with previous results in the literature. Subsequently, the results obtained for the damaged three dimensional plates indicate the behavior of the natural vibration frequencies with respect to the severity of the damaged boundary. This analysis can lead to an efficient technique for damage detection of structures in which joint or boundary damage plays a significant role in the dynamic characteristics. The results obtained from the Chebychev collocation solutions are seen to be in excellent agreement with those presented in the literature.
Mechanism of Occurrence of Self-Excited Oscillations of a Rotor With a Clearance Between Bearing Holder and Housing
Authors: Inagaki Mizuho , Ishida Yukio
Published: June 2012

It is well known that, in a rotor system with a radial clearance between a rotating part (ex. shaft) and a static part (ex. guide), a forward rubbing with the same angular speed as the rotational speed ω, a backward rubbing with an angular speed proportional to ω, and various kinds of nonlinear resonances occur. On the contrary, some rotor systems have a clearance between a movable but non-rotating part and a static part. For example, a squeeze-film damper bearing has a clearance between a bearing holder and housing. In such a system, a self-excited oscillation occurs in addition to various kinds of nonlinear resonances. In this paper, the characteristics of this self-excited oscillation are investigated and the mechanism of the occurrence of a self-excited oscillation is clarified by considering energy balance.
A Study of Kansei Engineering in PET Bottle Silhouette
Authors: Widiyati Khusnun , Aoyama Hideki
Published: June 2012

Today’s customers see the product not only based on its functionality and its value, but also based on its aesthetic view. And from day to day, the level of consumers’ aesthetic satisfaction is advanced. Companies have to struggle in recognizing and feeding the customers with higher and higher level of aesthetics design, in order to win the competition. Kansei Engineering is a powerful tool during product designs that analyze the design in relation with consumers’ feeling toward the product. In this saturated market, moreover, the application of Kansei Engineering might be a way out to provide a product emotionally attached to the customers’ feeling. PET bottles, particularly bottles distributed in Japan, is an example of “everyday-beverage-container” which has many variations in the shape. Among the many product attributes, product form/shape is one of the product attribute that can attract emotional attachment to the customer. In this paper, physical attributes of PET bottle which evoke consumers to have certain emotional attachment were evaluated using Kansei Engineering. In order to do this, 18 models of PET bottle generated using Taguchi Methods, and 9 emotional evaluation words were applied in a questionnaire. By using Taguchi Methods, important shape parameters that evoke customer to certain emotional feeling were identified. Validation to the Taguchi Methods’ finding was validated using Artificial Neural Network (ANN). The validation was performed by mapping the Kansei/emotional space to shape parameter space. Evaluation towards the result from Taguchi Methods and ANN was performed. Comparison between Taguchi Methods’ and ANN’s result showed that both result were correlated.
Preparing Mechanical Engineering Students for Product Design Professional Practice Through PBL: Planning and Execution of the Subject “Product Design Methodology”
Authors: Munoz-Guijosa J. M. , Di´az-Lantada A. , Echa´varri J. , Mun˜oz J. L. , Chaco´n E. , Lafont P. , Rodri´guez V. , Ferna´ndez D. , de la Guerra E.
Published: June 2012

Along with theoretical knowledge acquisition, knowledge application and professional competence acquisition must be important teaching objectives in any engineering subject. This is especially remarkable for subjects aiming the acquisition of product design knowledge, provided that, in actual professional practice, product design is done in multidisciplinary teams, taking into account technical and non-technical criteria, and with tight deadlines and budgets. This work describes the contents and teaching planning and execution for the subject “product design methodology” at the Mechanical Engineering Department of Universidad Polite´cnica de Madrid, aiming for the student acquisition of important professional competences to be used on professional product design practice, such as systematic decision making, global company view, task prioritizing, internal and external entrepreneurship, or teamwork, as well as hard competences such as design procedures, quality or project economics. Student teamwork examples from the problem-based learning (PBL) experience, together with internal and external surveys are shown to check the validity of the proposal.
A Novel Finite Element Method for a Class of Time Fractional Diffusion Equations
Authors: Sun H. G. , Chen W. , Sze K. Y.
Published: June 2012

Anomalous transport of contaminants in groundwater or porous soil is a research focus in hydrology and soil science for decades. Because fractional diffusion equations can well characterize early breakthrough and heavy tail decay features of contaminant transport process, they have been considered as promising tools to simulate anomalous transport processes in complex media. However, the efficient and accurate computation of fractional diffusion equations is a main task in their applications. In this paper, we introduce a novel numerical method which captures the critical Mittag-Leffler decay feature of subdiffusion in time direction, to solve a class of time fractional diffusion equations. A key advantage of the new method is that it overcomes the critical problem in the application of time fractional differential equations: long-time range computation. To illustrate its efficiency and simplicity, three typical academic examples are presented. Numerical results show a good agreement with the exact solutions.
Conceptual Design, Performance Evaluation and Dimensional Optimization of a Compact Acceleration Sensor Based on Flexure Parallel Mechanisms
Authors: Zhang Dan , Gao Zhen
Published: June 2012

In this paper, a tridimensional acceleration sensor based on flexure parallel mechanism (FPM) is presented. Three perpendicular compliant legs with compact monolithic structure are served as the elastic body for sensing the inertial signals in each direction. With integrated flexure hinges, each chain containing multiple revolute joints and cantilever beams are designed to carry compressive and tensile loads. Firstly, the structure evolution and kinematics modeling are introduced, followed by the multi-spring modeling of the directional compliance for the flexure leg. Then, the comprehensive finite-element analysis (FEA) including the strain of the sensitive legs, modal analysis for total deformation under different frequency is conducted. The compliances calculated by FEA and multi-spring model are compared. Finally, the dimensional optimization is implemented based on multi-population genetic algorithm to obtain the optimal flexure parameters. The proposed methods and algorithms are also useful for the analysis and development of other flexure parallel mechanisms.
Parameters Influencing the Perception of Geometrical Deviations in a Virtual Environment
Authors: Forslund Karin , Wagersten Ola , Tafuri Sebastian , Segerdahl Daniel , Carlsson Johan S. , Lindkvist Lars , So¨derberg Rikard
Published: June 2012

On car exteriors, geometrical variation, stemming from the manufacturing process, can distort the visible relationships between parts, i.e. the split-lines. In the automotive industry, non-nominal visualization is often implemented as a part of early concept reviews. Visualizing the results from a Computer-Aided Tolerancing analysis in a virtual environment allows to evaluate what deviations will be visible to customers and whether they can have a negative influence on the perceived product quality. The geometry, colors and materials of parts make some split-lines more visually sensitive than others because on them, potential deviations are especially disturbing to the onlooker. Moreover, the visual sensitivity is influenced by the context of product interaction in terms of illumination, reflections and the observer’s viewing angle. These factors need to be taken into account when determining tolerance levels to ensure that an industrial design concept will look good once produced. This paper presents a study of the influence split-line geometry and several visualization parameters have on the ability of test persons to identify geometrical deviations in a number of computer generated images. Additionally, eye-tracking was performed to identify what areas of the split-lines the test persons looked at while performing the task. The results confirm that the included split-lines are not equally sensitive to variation. Further, it is shown that the visualization settings indeed have an influence on the ability to detect variation but that the most sensitive settings differ between combinations of deviations and split-lines.
On the Design of Mobile Parallel Robots for Large Workspace Applications
Authors: Yang Hai , Krut Se´bastien , Pierrot Franc¸ois , Baradat Ce´dric
Published: June 2012

In this paper, several considerations for designing industry oriented robots which combine the mobility of legged robots and advantages of parallel mechanisms are outlined. For designing such optimized robots in terms of simplicity and performance, a topology study is done based on the mobility analysis. Applying some design constraints, potential topologies of such robots are identified. One architecture is chosen for designing a tripod robot. Both inverse and forward kinematic problems of this robot are derived in order to simulate its gait motion. The analysis and simulations show that: integrating some clamping devices and some lockable passive joints, six actuators are enough to build a legged manipulator which can not only perform 6-axis machining but can also walk on a curved supporting media.
Uncertainty Analysis and Its Application to Service Contracts
Authors: Kreye Melanie E. , Newnes Linda B. , Goh Yee Mey
Published: June 2012

Because of the transformation of market structures into the direction of servitization, manufacturing companies are forced to compete through the supply of services as opposed to products. Competing for these service contracts, particularly during bidding, the decision makers face various uncertainties that influence their decisions. This paper presents a holistic approach for identifying, modeling and representing these uncertainties to enable a more informed decision. As current literature lacks a holistic approach to characterize uncertainty, this paper proposes such an approach by classifying uncertainty into five layers. It is described how they offer an integrated approach to describing the uncertainty inherent in a situation. This classification is then applied to the bidding situation for a service contract in the form of a conceptual framework. This framework depicts the influencing factors on a bidding decision, namely, the contract conditions, internal company perspective, competitors and customer. To demonstrate the use of the uncertainty classification in detail the influencing factor of the customer is used as an exemplar. The uncertainty connected to the customer is characterized and the techniques for modeling the uncertainty are described. It is explained how the can be included in a decision matrix representing the probability of winning the contract.
Hybrid Modeling of Non-Linear Mechanical Systems: The Case of a Vehicle Shock Absorber
Authors: Di Dino Antonio , Biral Francesco , Bosetti Paolo
Published: June 2012

A large effort in the analysis of a physical system is the development of a model describing its behavior. The non-linear and time variant characteristic of many mechanical systems can be hardly represented by an analytical model without a remarkable increase of its complexity which contrasts with the need to obtain acceptable results in real-time such as in multibody simulations, system control design and Hardware in the loop (HIL) testing. In this context, the use of artificial neural networks are recognized as a powerful modeling tool to produce accurate model with reduced complexity. On the other hand their response to inputs outside the learning range may lead to unrealistic results. This paper presents an hybrid modeling technique, which combines a physical model with a neural network. The physical model describes the gross behavior of the system and the neural network captures the non-linear non-modeled behaviors or the effect of time-varying parameters. It is also proposed a method to limit the outside-range unpredicted responses. A RC car shock absorber is used as test case. Experimental results show that the neural network improves the physical model output capturing nonlinear aspects such as the hysteresis, the fluid leakage and the increase of its temperature.
Research on Complementary Connected Control Method of Two-Axes for a Combination of Base-Isolated and Conventional Structures
Authors: Fukuchi Syunsuke , Watanabe Toru , Seto Kazuto
Published: June 2012

In this paper, a novel combination of structures for connected-control mechanism (CCM) is presented. By coupling baseisolation and ordinary structures, the vibration suppression effect of CCM is expected to be expanded, while the stroke of base-isolation layer is hopefully suppressed. Experimental structures and CCM mechanism using magnetic dampers are built and excitation experiments are carried out. The effectiveness of CCM applied to base-isolation and ordinary structures is confirmed.
Evaluation Process Support in Mechatronics Design
Authors: Couturier Pierre , Lo Mambaye , Mouelhi Ouael
Published: June 2012

The design of mechatronic systems involves different technical and scientific disciplines and it is often difficult to arbitrate between engineers’ points of view so as to satisfy consumers’ needs. In order to converge to satisfactory tradeoffs, designers have to collaborate although they often can understand neither other designers’ issues nor their solving methods. Thus there is no guarantee each designer has spent the needed effort to reach some global optimum. Moreover, the number of design parameters is generally high and it may be difficult to grasp their influence on the design criteria that even can be contradictory. The purpose of this research is to propose methods and tools in order to help designers to evaluate candidate solutions. At this aim, an original heuristic based approach is proposed to compute non-dominated solution sets i.e. Pareto fronts. The analysis of the candidate solutions is facilitated using Self Organization Maps which provide designers with easy readable two dimensional cards. Our approach is fully illustrated in the case of the design of a 2-Degrees Of Freedom robot.
Multiparametric Analysis of Resonance Peak Vibrations for Nonlinear Jointed Structures
Authors: Petrov E. P.
Published: June 2012

A methodology has been developed to analyse and to optimize the resonance peak amplitudes and frequencies for essentially nonlinear periodic vibrations of jointed structures. The frequency domain analysis of realistic finite element models of jointed structures which can contain millions of degrees of freedom is performed. The detailed description of friction, gap and other types of the nonlinear contact interfaces in jointed structures is provided by contact interface elements. The resonance peak characteristics are calculated directly as functions of several parameters of contact interfaces and excitation. The efficiency of the methodology is demonstrated on a representative set of practical test cases.
Flexoelectric Signals on Rings in Transverse Motions
Authors: Hu S. D. , Li H. , Tzou H. S.
Published: June 2012

Dynamic sensing is essential to effective closed-loop vibration control of precision structures and systems. In a centrosymmetric crystal subjected to inhomogeneous deformation, where piezoelectricity is absent, only the strain gradient contributes to the polarization known as the “flexoelectricity.” In this study, a flexoelectric layer is laminated on ring shells to monitor the natural modal signal distributions. Due to the strain gradient, only the bending strain component contributes to the output signal; the total signal has two components respectively induced by the transverse modal oscillation and the circumferential modal oscillation. Analogue to the signal analysis, the sensitivity can also be defined in two forms: a transverse sensitivity induced by the transverse modal oscillation and a transverse sensitivity induced by the circumferential modal oscillation. Analysis data suggest that the transverse modal oscillation dominante the flexoelectric signal generation and its magnitude/distribution shows nearly the same as the total signal. Furthermore, voltage signals and signal sensitivities are evaluated with respect to ring mode, sensor segment size, ring thickness, and ring radius in case studies. The total signal increases with mode numbers and sensor thicknesses, decreases with sensor segment size and ring radius, and remains the same with different ring thicknesses. These data serve as design guidelines to select proper parameters for practical engineering applications using flexoelectric transducers.
Optimal Design for Additive Manufacturing: Opportunities and Challenges
Authors: Doubrovski Zjenja , Verlinden Jouke C. , Geraedts Jo M. P.
Published: June 2012

Additive Manufacturing (AM) represents a maturing collection of production technologies also known as rapid prototyping, rapid manufacturing and three-dimensional printing. One of the most promising aspects of AM is the possibility to create highly complex geometries. Despite a growing body of knowledge concerning the technological challenges, there is a lack of methods that allow designers to effectively deal with the new possibilities. This article presents a literature survey on the impact that AM can have on design. The survey was focused on the new opportunities of fabrication processes, the relationship between structure and performance, and optimization approaches. We applied Olsen’s three-link chain model to relate product structure with performance, linked by strength, stiffness, compliance, dynamic, thermal, and visual properties. We also use this model to base our proposed Design for Additive Manufacturing (DfAM) method. The findings show that there is a growing body of knowledge in the field of design for AM (DfAM), yet only considers a subset of properties. Furthermore, the knowledge on materials, computational optimization, computer aided design, and behavioral simulation embody separated domains and related software support. This is in contrast with design engineering, which requires a holistic approach to conceptualize new products.
Energy Generation Mechanism of Nanorings in Circumferential Oscillations
Authors: Hu S. D. , Li H. , Tzou H. S.
Published: June 2012

This study focuses on the nanopiezoelectric energy harvesting mechanism of free-floating zinc oxide (ZnO) nanorings. Inner and outer surfaces of a ZnO nanoring are both deposited with an electrode layer that are uniformly and symmetrically segmented into series of couples to serve as distributed energy generators. The generation mechanism of voltage signal is analyzed first, followed by the energy generation analysis. Because of the cancellation of the electric potentials across the nanoring thickness induced by bending strains, the membrane strain is the only contribution to the output voltage and energy generations. The membrane (circumferential) oscillation modes of the nanoring are considered for the analysis of energy generation mechanism. Distributions of the output voltage signal and the generated energy are evaluated with respect to various nanoring modes and design parameters, e.g., nanoring radii and electrode segment sizes. Signal average and cancellation effect reduces the generated signal and energy when the segment size enlarges. The overall energy is also calculated by summing up energies generated from all energy harvesters of the whole nanoring. Analysis suggests that more energy can be generated when the segment size reduces. The energy distributions with respect to nanoring modes provide a design guideline to select proper segmentation and nanoring radius, as well as optimal distributions of electrode patches to achieve highest energy harvesting efficiency for nanoring generators.
A Modular Design Approach to Improve the Life Cycle Performance Derived From Optimized Closed-Loop Supply Chain
Authors: Chung Wuhsun , Okudan Gu¨l E. , Wysk Richard A.
Published: June 2012

Growing concerns for the environment should make every designer more carefully consider product design for the life cycle (DFLC). Although modularity is recognized for its potential to incorporate life cycle considerations into product architecture design, most modular design methods in the literature concentrate on generating highly-modular product architectures but lack the capability for assessing life cycle consequences of these modules in a supply chain. This paper proposes a methodology to find a robust modular architecture with minimal life cycle costs and environmental impacts at the design configuration stage. The objective of the proposed methodology is not to maximize modularity, but to adopt life cycle costing and life cycle assessment of a product in a closed-loop supply chain to identify the most beneficial modular structure. Further, capacity influence of the existing processing facilities in the supply chain on life cycle costs and environmental impacts is evaluated and discussed in this paper.
Multi-Group Consensus of Heterogeneous Fractional-Order Nonlinear Agents via Pinning Control
Authors: Sun Wei , Chen YangQuan , Li Changpin
Published: June 2012

The present work concerns the multi-group consensus behavior of directed complex networks. The network consists of agents with heterogeneous fractional-order non-linear dynamics. It can be divided into several groups due to their dynamics or equilibriums. Each group will be stabilized at an equilibrium and different groups may have different steady state values. A necessary and sufficient condition is provided for the proposed pinning control law to be locally Mittag-Leffler stable. The conclusion turns to guarantee the exponential stable for integer-order systems. The collection of heterogeneous equilibriums is determined by the geometric multiplicity of the zero eigenvalue respect to the graph Laplacian. Simulations on fractional-order chaotic systems demonstrated the conclusions.