bluuebunny/crossref_metadata_2025 huggingface dataset:
The Establishment of Novel Structure Representation Models for Several Kinds of Mechanisms
Authors: Ding Huafeng , Zhao Jing , Huang Zhen
Published: July 2010

This paper attempts to establish the unified topological models and corresponding mathematical representations for planar simple joint, multiple joint and geared (cam) kinematic chains. First, the conventional topological representation models of kinematic chains are introduced. Then new topological models of multiple joint and geared (cam) kinematic chains, which are derived from the topological graph of simple joint kinematic chains, are presented. The characteristics of the new topological graphs and their associations with the topological graph of simple joint kinematic chains are also addressed. The most important merit of the new topological graphs is that it makes it much easier to do unified structure synthesis and further establish conceptual design platform for various planar mechanisms of these kinds.
Vibration Control of a Seat Suspension System Using Magnetorheological Damper
Authors: Metered H. , Bonello P. , Oyadiji S. O.
Published: July 2010

Seat suspension system is critical to the ride comfort experience of a vehicle’s driver and passengers. The use of a magnetorheological (MR) damper in a seat suspension system has been shown to offer significant benefits in this regard. Most research on seat MR dampers has applied active control strategies to command the MR damper, which is an inherently semi-active device. This paper introduces a more suitable semi-active control strategy for an MR damper used in a seat suspension, enabling more effective control. The proposed control system comprises a system controller that computes the desired damping force using a sliding mode control algorithm, and a neural-based damper controller that provides a direct estimation of the command voltage that is required to track the desired damping force. The seat suspension system is approximated by base-excited single degree of freedom system. The proposed semi-active seat suspension is compared to a passive seat suspension for prescribed base displacements. These inputs are representative of the vibration of the sprung mass of a passive or semi-active quarter-vehicle suspension under bump or random-profile road disturbance. Control performance criteria such as seat travel distance and seat acceleration are evaluated in time and frequency domains, in order to quantify the effectiveness of proposed semi-active control system. The simulated results reveal that the use of semi-active control in the seat suspension provides a significant improvement in ride comfort.
ICAP: A Compliant Joint Planar Mechanism Dynamic Analysis Program
Authors: Sutherland George H.
Published: July 2010

Using the Implicit Constraint Approach (ICA), a general procedure is presented for analyzing mechanism or robotic devices of arbitrary topology and complexity. The ICA allows for a compact formulation with the unique feature of automatically including real joint stiffness and damping characteristics. This formulation is the core of a computer program, ICAP, that directly provides all the body kinematics and joint reaction forces of any planar mechanism. An interactive graphic user interface to the program’s physics engine provides a simple method for describing the mechanical system and supporting the presentation of the analysis results. ICAP was developed to be used in the MATLAB environment, but could be modified for stand-alone use. Numerical examples are presented for a truck full (left and right side) front suspension and a Watt six-bar linkage.
Structure Synthesis of Rank-Degenerated Serial Mechanisms and Over-Constrained Single-Loop Kinematic Chains
Authors: Yang Ting-Li , Liu An-Xin , Jin Qiong , Luo Yu-Feng , Shen Hui-Ping , Hang Lu-Bing
Published: July 2010

Based on the Position and orientation characteristic (POC) equation of serial mechanisms proposed by the author, this paper presents a novel systematic approach for structure synthesis of rank-degenerated serial mechanisms and over-constrained single-loop kinematic chains (KCs) (excluding the Bennett mechanism etc). This approach is totally different from the approaches based on the screw theory and based on the displacement subgroup, and only simple mathematical tools (vector algebra, etc.) are used. Using this approach, the structure types of serial mechanisms with the specified ranks and the specified degree of freedom (DOF) are synthesized firstly. After that, using the structure types of the obtained serial mechanisms, structure types of over-constrained single-loop KCs with the specified ranks and the specified DOF can be generated in a straightforward way. The structure types of the obtained serial mechanisms can be used as branches of parallel mechanisms. The structure types and the ranks of the obtained over-constrained single-loop KCs can be used to calculate the DOF of multi-loop mechanisms. In fact, the systematic approach proposed in this paper is a key component of the systematic approach for structure synthesis of parallel mechanisms.
Integrated Decision Model for Interrelated Sub-Problems of Part Design or Selection, Machine Loading and Machining Optimization
Authors: Mgwatu M. I. , Opiyo E. Z. , Victor M. A. M.
Published: July 2010

In the work presented in this paper, we made an attempt to integrate the decisions for interrelated sub-problems of part design or selection, machine loading and machining optimization in a random flexible manufacturing system (FMS). The main purpose was to come up with an optimization model for achieving more generic and consistent decisions for the FMS and which can be practically implemented on the shop floor to help designers and other engineers in several ways, including, for instance, to optimize the designs of parts for specific FMS. In order to attain the generic decisions, an integer nonlinear programming (INLP) problem was formulated and solved to maximize the FMS throughput. Based on the results, the part design or selection, machine loading and machining optimization decisions can be simultaneously made. To get more insights of the results and also to check the validity of the model, a two-factor full factorial design was implemented for the sensitivity analysis, analysis of variance (ANOVA) and residual analysis. The computational analyses show that the tooling budget and available processing time were both statistically significant to throughput and confirmed that the model is valid with the data normally distributed.
Simulations of Surface Defects Characterization Using Force Modulation Atomic Force Microscopy
Authors: Pishkenari Hossein Nejat , Meghdari Ali
Published: July 2010

This paper is devoted to the characterization of the surface defects using a recently developed AFM technique named as frequency and force modulation AFM (FFM-AFM). The simulated system includes a recently developed gold coated AFM probe which interacts with a sample including single-atom vacancy and impurities. In order to examine the behavior of the above system including different transition metals, molecular dynamics (MD) simulation with Sutton-Chen (SC) interatomic potential is used. Along this line, an imaging simulation of the probe and sample is performed, and the effects of the horizontal scan speed, the effective frequency set-point, the cantilever stiffness, the tip-sample rest position and the cantilever quality factor on the resulting images are investigated. Using a proposed optimum controlling scheme for the excitation force amplitude, the cantilever horizontal speed can be maximized.
Probabilistic Analysis of Manufacturing Uncertainty in Turbine Blades
Authors: Thakur Nikita , Keane Andy , Nair Prasanth B.
Published: July 2010

An important part in the efficient and robust design of turbine blades is to capture the details of any manufacturing uncertainty. However, the data available detailing the manufacturing uncertainty inevitably contains variability due to inherent errors in any measurement process. The presented work proposes a methodology that employs existing probabilistic data analysis techniques, namely, Principal Component Analysis (PCA), Multivariate Analysis of Variance (MANOVA) and Fast Fourier Transform (FFT) analysis for separation of the measurement error from measurement data to obtain the underlying manufacturing uncertainty. This manufacturing uncertainty is further segregated in terms of the manufacturing uncertainty with time and the blade to blade manufacturing error. A method for dimensionality reduction is employed which utilizes prior information available on the variance of the measurement error for each measurement location. The application of the proposed methodology leads to reconstruction of new datasets that may be used for generating 3-d models of the manufactured blade shapes. These 3-d models may then be used further for Finite Element Analysis (FEA) in standard FEA tools.
Proposal of an Ecodesign Assessment Methodology by Using a Weighted Checklist
Authors: Kishita Yusuke , Low Bi Hong , Fukushige Shinichi , Umeda Yasushi , Suzuki Atsushi , Kawabe Takao
Published: July 2010

Environmentally conscious design or ecodesign plays one of the most important roles to create products with less environmental impact targeting the sustainable society. Manufactures often use checklists to support design improvements of products and to obtain eco-labels, such as Eco Mark in Japan. Current checklists are, however, insufficient to support designing products rationally because the relationship between the individual requirements of current checklists and environmental impact is undetermined. This paper proposes a method for supporting ecodesign assessment by developing a weighted checklist from a conventional checklist. This weighted checklist calculates ecodesign achievement based on the potential environmental improvement of each requirement, derived by the life cycle simulation. The result of a case study involving a digital duplicator showed the proposed method successfully clarified requirements that should be improved in the present product. When design improvements are applied, the assessment of the product’s CO2 emission is improved by 8%.
An Inertially-Actuated Passive Dynamic Step Climbing Wheeled Robot
Authors: Humphreys John , Hong Dennis
Published: July 2010

For their inherent stability and simplicity, wheeled robots are very common in robotics applications — but a major drawback of wheeled robots is their inability to navigate over large obstacles or steps without assistance. Active systems that have been designed for use on wheeled robots to lift the robot over a step — such as USU’s T3 and Virginia Tech’s IMPASS — are effective, but are limited due to the size, cost, and power required for the additional actuators. A novel, inertially actuated, passive dynamic system, excited by the motion of the robot, is introduced to allow a wheeled robot to “pop a wheelie” on each axle and hop over a step. The system investigated here is a sliding mass-spring that shifts forward and backward based on the acceleration of the base robot. By coordinating the acceleration and deceleration of the robot, the front wheels can lift over a step and the rear wheels can be pulled up afterward — both actions being a product of inertial actuation. Key advantages of this system are that the design is simple, cost-effective, and can be adjusted and retrofit to a different wheeled robot in the future with little effort. This paper presents the development of a novel inertially actuated, passive dynamic step climbing wheeled robot. Derivations of the dynamic model of the inertially actuated system are given and a computer simulation and experiments of an implementation of this sliding mass system are presented, followed by conclusions with possibilities for future work.
New Method of a Calculation of Equidistant Coordinates of an Involute Tooth Profile for FEM Calculations of Gears
Authors: Nemcek Milos , Dejl Zdenek
Published: July 2010

Toothed gears with an internal and an external gearing are widely dispersed nowadays. The extent and versatility of these gears are increasing not only in mechanical engineering. It is necessary to use high quality FEM software for a competent assessment of these gearings. However one problem occurs here — it is not easy to create an input data file describing the tooth profile shape and its root fillet in a 3D space. Moreover with regard to the type of a tooth profile curve (an involute), it is very difficult to enumerate equidistant spacing among points laying on this curve when preparing data for a FEM calculation. This equidistant spacing is important for good contact stress analysis during teeth meshing. It is impossible to get these data by ordinary methods. This contribution presents a numerical method suitable for calculating these equidistant spacing coordinates of points.
Interval Uncertainty Reduction and Single-Disciplinary Sensitivity Analysis With Multi-Objective Optimization
Authors: Li M. , Williams N. , Azarm S.
Published: July 2010

Sensitivity analysis has received significant attention in engineering design. While sensitivity analysis methods can be global, taking into account all variations, or local, taking into account small variations, they generally identify which uncertain parameters are most important and to what extent their effect might be on design performance. The extant methods do not, in general, tackle the question of which ranges of parameter uncertainty are most important or how to best allocate investments to partial uncertainty reduction in parameters under a limited budget. More specifically, no previous approach has been reported that can handle single-disciplinary multi-output global sensitivity analysis for both a single design and multiple designs under interval uncertainty. Two new global uncertainty metrics, i.e., radius of output sensitivity region and multi-output entropy performance, are presented. With these metrics, a multi-objective optimization model is developed and solved to obtain fractional levels of parameter uncertainty reduction that provide the greatest payoff in system performance for the least amount of “investment”. Two case studies of varying difficulty are presented to demonstrate the applicability of the proposed approach.
Representation and Automated Generation of Analysis Feature Model for Finite Element Analysis
Authors: Cao Weijuan , Wu Haipang , Jiang Yuqin , Liu Yusheng , Gao Shuming
Published: July 2010

Integration of finite element analysis (FEA) into design is important for complex product development. However, how to automatically and robustly generate the analysis model from the design model, and how to organize information needed by CAD and FEA for the efficient integration is still a big problem. In this study, analysis feature model (AFM) is proposed and developed as a central model for design and analysis. Five kinds of information are contained in AFM which are analysis-related information, geometric-related information, element-related information, boundary condition and coupling information between features. A systematic approach is elaborated to automatically generate the AFM from the design model which mainly contains four steps: automated recognition of analysis features, decomposition of the design model, reduction and combination into AFM. The analysis model can be easily obtained from the AFM. At last the proposed method is implemented and some examples are given.
The Eel-Like Robot
Authors: Boyer F. , Chablat D. , Lemoine P. , Wenger P.
Published: July 2010

The aim of this project is to design, study and build an “eel-like robot” prototype able to swim in three dimensions. The study is based on the analysis of eel swimming and results in the realization of a prototype with 12 vertebrae, a skin and a head with two fins. To reach these objectives, a multidisciplinary group of teams and laboratories has been formed in the framework of two French projects.
Increasing Innovation in Multi-Function Systems: Evaluation and Experimentation of Two Ideation Methods for Design
Authors: Weaver Jason M. , Kuhr Rachel , Wang Dennis , Crawford Richard H. , Wood Kristin L. , Jensen Dan , Linsey Julie S.
Published: July 2010

Many methods for design have been explored as the engineering community seeks to increase the efficiency, quality, and novelty of innovation. Some design methodologies are well equipped for use with any problem; others are best suited for specific domains or applications. Recent studies have developed two new independent methods for design. The first, WordTree Design-by-Analogy, uses a graphical structure of related words to help identify far-field analogies that have relevance to a given problem. The second method, Transformation Design, describes the mechanics and characteristics that drive the transformation of a reconfigurable mechanical system from one state to another. This paper presents a study of the effectiveness of these two methods in generating concepts for a specific problem statement requiring multiple sets of capabilities, i.e., tagging and tracking vehicles for military or civilian law enforcement purposes. Forty-one mechanical engineering students were assembled into groups and given specific guidelines to follow in generating concepts. A typical full-factorial experiment and ANOVA analysis was used to compare the effect of using the two design methods, as well as the interaction between them. Results from the design teams were evaluated quantitatively by the number concepts generated. Analysis of these results revealed that using the Transformation Design method increased the number of concepts developed by 25–30%. Use of the WordTree method was not judged to increase the number of concepts generated; however, the novelty and diversity of solutions were distinct for this method compared to Transformation Design or the control group.
Lateral Thin-Film Piezoelectric Actuators for Bio-Inspired Micro-Robotic Locomotion
Authors: Oldham Kenn , Rhee Choong-Ho , Ryou Jyoung-Hoon , Polcawich Ronald , Pulskamp Jeffrey
Published: July 2010

Thin-film lead-zirconate-titanate (PZT) actuators are a potential enabling technology for autonomous micro-robots with locomotion abilities rivaling biological systems. Actuators capable of supplying the large forces and extended displacements needed to drive terrestrial micro-robotic locomotion have been designed and tested. These actuators use a combination of upward and downward unimorph bending to generate in-plane robotic joint motion. 500 μm by 100 μm actuators have demonstrated forces greater than 5 mN over almost 1 μm stroke length at just 20 V. These actuators can be leveraged to drive angular displacement of high-aspect ratio silicon flexures. Actuators are currently being integrated into flexural arrays to produce joint angles comparable to insects. Stacks of these silicon joint structures may be used to reinforce load-bearing capacity of the completed micro-robotic legs. Dynamic simulations of hexapedal and many-legged robots less than one centimeter in length utilizing these actuator-joint structures indicate potential payloads ranging from 50 to 200 mg, depending on the joint design, and walking speeds up to approximately 4 cm/s.
An Empirical Approach to Modeling the Friction Coefficient for Wheel-Rail Contact
Authors: Lee HyunWook , Sandu Corina , Holton Carvel , Ahmadian Mehdi
Published: July 2010

The coefficient of friction (CoF) is one of the most important parameters for the contact between the wheel and the rail. Accurate estimation or measurement of the CoF has a very important role, both in terms of modeling the train dynamics and in terms of reducing operational costs in the long-term. For ease of implementation, since the nature of the wheel-rail contact dynamics is very complex, the assumption of a constant CoF is still used in most theoretical studies. Nevertheless, experimental work indicates that the CoF depends on dynamic changes in various wheel-rail conditions, like sliding velocity, contact patch shape and size for stick and sliding region, wheel and rail geometry, wheel vibration, rail surface roughness and/or lubrication, etc. In this paper we present the proposed equation to model the nonlinear dry friction coefficient at the wheel-rail contact. The friction coefficient is calculated at the three different values for change in the damping ratio while maintaining all the other conditions the same. As expected, the analysis performed to estimate the dry friction coefficient based on the proposed equation and using NUCARS® simulation results shows that the coefficient of friction has a highly nonlinear dependence on its parameters.
A Fully Coupled FEM Model of Electromechanically Actuated MEMS With Squeeze Film Damping
Authors: Hannot Stephan D. A. , Rixen Daniel J.
Published: July 2010

A specific type of Microsystems or MEMS is the so called RF-MEMS switch. In contrast to MEMS resonators switches generally do not operate in a vacuum. Therefore at the small scales of MEMS fluid (or air) damping is the most dominant damping form. This means that if one is interested in transient or frequency behavior a proper damping model is required. This paper presents a way of using the non-linear Reynolds equation to model the squeeze film damping that is often the type of fluid damping present in these switches. The formulation is provided ready for FEM implementation. Also the tangent matrices required for linearized eigen frequencies are derived. The equations are tested on a model of simple micro switch. The results show that with this model it is possible to predict the damped motion as well as the frequency behavior. The frequency results also show that damping shifts the zero frequency point away from the pull-in point. With a simple mechanical contact model it is also possible to model the closing and opening transient of a microsystem.
Robustness of Residual Stresses in Castings and an Improved Process Window
Authors: Hofwing Magnus , Stro¨mberg Niclas
Published: July 2010

In this work the robustness of residual stresses in finite element simulations with respect to deviations in mechanical parameters in castings is evaluated. Young’s modulus, the thermal expansion coefficient and the hardening are the studied parameters. A 2D finite element model of a stress lattice is used. The robustness is evaluated by comparing purely finite element based Monte Carlo simulations and Monte Carlo simulations based on linear and quadratic response surfaces. Young’s modulus, the thermal expansion coefficient and the hardening are assumed to be normal distributed with a standard deviation that is 10% of their nominal value at different temperatures. In this work an improved process window is also suggested to show the robustness graphically. By using this window it is concluded that least robustness is obtained for high hardening values in combination to deviations in Young’s modulus and the thermal expansion coefficient. It is also concluded that quadratic response surface based Monte Carlo simulations substitute finite element based Monte Carlo simulations satisfactory. Furthermore, the standard deviation of the responses are evaluated analytically by using the Gauss formula, and are compared to results from Monte Carlo simulations. The analytical solutions are accurate as long as the Gauss formula is not utilized close to a stationary point.
Analysis and Visualization of Project Structure Using Linkography: Focussing Project Risk Management
Authors: Gericke Kilian , Kleinod Bjo¨rn , Blessing Lucienne
Published: July 2010

Product development projects are difficult to plan due to complexity, dynamics, lack of transparency and polytely. Risk Management is often used to cope with this situation. Linkography (originally proposed by Goldschmidt) is adapted with the aim to ease the effort of the Risk Management process. The elements of the original method are transferred to the area of Project Risk Management, complemented by a real time scale, and cost information of elements. Linkography is used to focus all Risk Management activities on those work packages, which might affect the project the most in the case of failing the expected outcome. The number of links to other work packages, its duration and its costs defines the criticality of a work package. By applying Linkography as a Risk Management method, a prioritized list of work packages can be generated which pass consecutively through the usual Risk Management process. Unlike other methods, Linkography supports the user in a visual manner. Hence, Linkography can easily be used for communication with unskilled stakeholders.
Port-Based Ontology Semantic Similarities for Module Concept Creation
Authors: Cao Dongxing , Ramani Karthik , Fu Ming Wang , Zhang Runli
Published: July 2010

The modularity indicates a one-to-one mapping between functional concepts and physical components. It can allow us to generate more product varieties at lower costs. Functional concepts can be described by precise syntactic structures with functional terms. Different semantic measures can be used to evaluate the strength of the semantic link between two functional concepts from port ontology. In this paper, different methods of modularity based on ontology are first investigated. Secondly, the primitive concepts are presented based on port ontology by using natural language, and then their semantic synthesis is used to describe component ontology. The taxonomy of port-based ontology are built to map the component connections and interactions in order to build functional blocks. Next, propose an approach to computing semantic similarity by mapping terms to functional ontology and by examining their relationships based on port ontology language. Furthermore, several modules are partitioned on the basis of similarity measures. The process of module construction is described and its elements are related to the similarity values between concepts. Finally, a case is studied to show the efficiency of port ontology semantic similarity for modular concept generation.
An Automated Implementation of a Cantilever Calibration Technique for Heavy Fluid Loading Environments
Authors: Kennedy Scott J. , Cole Daniel G. , Clark Robert L.
Published: July 2010

In a recently submitted paper, a technique is presented for the force calibration of atomic force microscopy (AFM) cantilevers under heavy fluid loading conditions, such as those commonly found in liquid environments. A Matlab program had been made available that automates this technique. In this paper, the analysis performed by this program is explained with specific attention to the details that do not appear in the original description of the calibration technique, but arise in the automated implementation.
Automatic Virtual Entity Simulation of the Symbolic Schemes Generated in Conceptual Design Processes
Authors: Wang Yu-Xin , Li Yu-Tong
Published: July 2010

The developing new products of high quality, low unit cost, and shortening lead time to markets are the key elements required for enterprises to obtain competitive advantages. In order to improve the creativity and shorten lead time to markets, a methodology of automatic virtual entity simulation of conceptual design results is proposed. At the end of conceptual design, the conceptual design results are expressed in the symbolic schemes generated by the computerized approach with a higher capability to obtain the innovative conceptual design. Then, the symbolic scheme is identified into basic mechanisms and their connections. To the identified basic mechanisms, their kinematic analysis is carried out by matching basic Barranov trusses, and their virtual entities are modeled based on feature-based technique and encapsulated as one design object. Based on the structures of the basic mechanisms and their connections, a space layout to the mechanical system corresponding to the symbolic scheme is fulfilled then. With the pre-assembly approach, all parts in the mechanical system are put onto proper positions where the constraint equations are met. In this way, the virtual entity assembly model of the mechanical system corresponding to the symbolic scheme is set up. Changing the positions of the driving links continually, the virtual entity simulation of the mechanical system will be fulfilled. As a result, with the aid of this approach, we can not only obtain innovative conceptual design results with excellent performances, but also shorten the design time and the cost of product developments.
Development of Adaptive RBF-HDMR Model for Approximating High Dimensional Problems
Authors: Shan Songqing , Wang G. Gary
Published: July 2010

Modeling or approximating high dimensional, computationally-expensive, black-box problems faces an exponentially increasing difficulty, the “curse-of-dimensionality”. This paper proposes a new form of high-dimensional model representation (HDMR) by integrating the radial basis function (RBF). The developed model, called RBF-HDMR, naturally explores and exploits the linearity/nonlinearity and correlation relationships among variables of the underlying function that is unknown or computationally expensive. This work also derives a lemma that supports the divide-and-conquer and adaptive modeling strategy of RBF-HDMR. RBF-HDMR circumvents or alleviates the “curse-of-dimensionality” by means of its explicit hierarchical structure, adaptive modeling strategy tailored to inherent variable relation, sample reuse, and a divide-and-conquer space-filling sampling algorithm. Multiple mathematical examples of a wide scope of dimensionalities are given to illustrate the modeling principle, procedure, efficiency, and accuracy of RBF-HDMR.
On the Effect of Contact Friction and Contact Compliance on the Grasp Performance of Underactuated Hands
Authors: Kragten Gert A. , Bosch H. Allert , van Dam Teunis , Slobbe Johan A. , Herder Just L.
Published: July 2010

Although adding compliant, frictional material on robotic fingers to improve the performance is generally accepted, at least for underactuated hands this effect is hardly quantified. In this study, the phalanges of an underactuated hand in an experimental setup were firstly covered with material of different friction coefficients but equal contact compliance, while the force to pull a grasped object completely out of the hand was measured. Then, the phalanges were covered with material of different compliance while the same measurements were done. In the latter experiment, the effect of contact friction was eliminated by using a specially designed testbed that emulates a frictionless object. The experiments showed an increase of the maximal pull force by 250% when the friction coefficient of the contact material increased from 0.25 to 1.51. The compliance of the contact material had a marginal effect on this maximum force. Finally, the pull force was calculated by a static grasp model, incorporating contact friction and linear contact compliance. Trends similar to the experiments were observed in these simulations.
Testbed of a Novel Robotic Pitch-Roll Wrist for Parameter Identification: Modeling and Analysis
Authors: Ma Xiao Qing , Chopra Vikram , Angeles Jorge , Haugaard Martin Asger
Published: July 2010

The paper reports work in progress on the development of an innovative gearless pitch-roll wrist (PRW) for robotic applications. The PRW bears the morphology of a bevel-gear differential, its novelty lying in the absence of gears. Indeed, the PRW motivating this study is based on cams and rollers, intended to overcome the drawbacks of their bevel-gear counterparts—backlash, Coulomb friction and low stiffness. A testbed designed for parameter identification is introduced here. The paper discusses the mathematical modeling of the testbed, starting from its iconic model. The mathematical model is used to obtain the frequency response of the whole testbed, regarded as a multiple-input-multiple-output system, under the assumption that the parts of the spherical epicyclic train are rigid. The numerical values for the inertia parameters used in the model were taken from CAD models, those for stiffness and damping, as yet unknown, were estimated from a similar testbed reported elsewhere. The work ahead targets the experimental derivation of the Bode plots of the testbed, from which the numerical values of its inertia, stiffness and damping parameters are to be estimated. Moreover, having computed the stiffness and damping parameters of the testbed, the next step will be to drive the PRW at high frequencies, of the order of 1 kHz, to enable the identification of the stiffness and damping parameters of the PRW proper.
Design of Semiactive Vehicle Suspension Controls in Frequency Domain
Authors: Song Xubin , Cao Dongpu
Published: July 2010

Through the simulation study of a semiactive quarter car suspension, this paper is to expatiate on the control algorithm documented in the United States Patent 6,873,890 [1]. That patent presents a new method to design semiactive suspension controls in the frequency domain. As is well known, suspension related dynamics has two dominant modes in the working frequency range up to 25Hz. As such, the suspension dynamic system has three distinguishable frequency sections. In order to achieve better performance, different controls have to be applied to each frequency section, respectively. The significant core part of the patented algorithm is to provide an approach to identify the excited frequencies in real time that are transmitted through the vehicle suspension. Then different controls of such as skyhook, groundhook and other damping strategies are combined accordingly to accomplish the best performance overall. Thus through the suspension control the vehicle dynamics (such as ride and handling) is expected to be improved in the broad frequency range in comparison to passive suspensions with a trade-off design.
Lightweight Engineering of Military Vehicles Through Requirements Analysis and Function Integration
Authors: Maier Jonathan R. A. , McLellan James M. , Mocko Gregory , Fadel Georges M. , Brudnak Mark
Published: July 2010

The trend toward lighter-weight vehicles in the private sector has been pushed by demands to improve fuel economy, improve dynamic performance, and reduce material and transportation costs. The same demands exist and are even more acute for military vehicles. The reduction of weight across a military vehicle platform can affect hundreds of thousands of vehicles with dramatic ramifications for military budgets, logistic support, deployment time and cost, and other factors critical to national defense. In this paper we report on methods developed for requirements analysis and function integration based on a modeling framework (developed in previous work) which captures requirements, functions, working principles, components, component parameters, test measures, and tests. We also show that the problem of assigning the mass of individual components to requirements is not solvable in practice. The methods are demonstrated using a case study of the United States Department of Defense Family of Medium Tactical Vehicles (FMTV).
Lean Thinking and Product Innovation in the Furniture Industry
Authors: Medeiros Albertina Pereira , Seibel Silene , Natal Jorge Renato , Fernandes Anto´nio Augusto
Published: July 2010

The pressure to innovate has been particularly strong in industry traditional sectors if they are to survive to competitors with lower labour costs. Furniture has become a commodity product in some international markets. In most countries the furniture industry is highly fragmented and family owned. In this context the decision to introduce and launch new products rests solely on the owner, without considering the costumer needs. At the same time, the companies do not have an organizational structure and a formal process for managing new product development (NPD). In recent years “lean thinking” has gained increased popularity as a new paradigm of product design and manufacturing. This is due to the success which Toyota attained worldwide. The present research, still in progress, aims to answer the following research question: “Can lean thinking principles, methods and tools be applied in product development in a traditional sector such as the furniture industry?” To answer this question a research programme has been designed based on a cross-case analysis in two distinct cultural settings: the Portuguese and Brazilian furniture industries. Two in-depth case studies are in progress in two firms (one in Portugal and another in Brazil). The research programme is focused on the following principles: organize to balance functional expertise, to establish customer defined value, front load the product development process and to use tools for standardisation. The application of these principles has as its main goal to eliminate waste during the process chain and attain excellence. The first phase of the work looked into the subsystem People, with particular emphasis on the organizational structure. The preliminary results, obtained up to now, show that there is no formal product development system currently in place in the studied companies. This results in an inefficient flow of information in all phases of the product development, leading to numerous sources of waste.
A Context-Aware Information Model for Elderly Homecare Services in a Smart Home
Authors: Zhou Feng , Jiao Jianxin Roger , Chen Songlin , Zhang Daqing
Published: July 2010

One of the critical situations facing the society across the globe is the problem of elderly homecare services (EHS) due to the aggravation of the society coupled with diseases and limited social resources. This problem has been typically dealt with by manual assistance from caregivers and/or family members. The emerging Ambience Intelligence (AmI) technology suggests itself to be of great potential for EHS applications, owing to its strength in constructing a pervasive computing environment that is sensitive and responsive to the presence of human users. The key challenge of AmI implementation lies in context awareness, namely how to align with the specific decision making scenarios of particular EHS applications. This paper proposes a context-aware information model in a smart home to tackle the EHS problem. Mainly, rough set theory is applied to construct user activity models for recognizing various activities of daily living (ADLs) based on the sensor platform constructed in a smart home environment. Subsequently, issues of case comprehension and homecare services are also discussed. A case study in the smart home environment is presented. Initial findings from the case study suggest the importance of the research problem, as well as the feasibility and potential of the proposed framework.
Observer Design to Estimate Shank Angle for Motion Control of an Underactuation Biped Robot
Authors: Dehghani Reza , Fattah Abbas
Published: July 2010

In this paper, a nonlinear observer is designed to estimate the angle of leg for an underactuation biped robot with four links and three actuators. First, using a diffeomorphism transformation, the nonlinear system changes to a system with triangular form. Then, a nonlinear observer, based on the second order sliding mode, is designed for the transformed system. The control law uses only measurable variables, that can be estimated by the observer, for tracking the desired stable gait. Finally, simulation results are presented to show the behavior of biped robot and convergency of the observer in finite time during stable walking.
Supporting Biomimetic Design Through Categorization of Natural-Language Keyword-Search Results
Authors: Ke Ji , Wallace J. S. , Shu L. H.
Published: July 2010

Biology is a good source of analogies for engineering design. One approach of retrieving biological analogies is to perform keyword searches on natural-language sources such as books, journals, etc. A challenge of retrieving information from natural-language sources is the potential requirement to process a large number of search results. This paper describes a categorization method that organizes a large group of diverse biological information into meaningful categories. The benefits of the categorization functionality are demonstrated through a case study on the redesign of a fuel cell bipolar plate. In this case study, our categorization method reduced the effort to systematically identify biological phenomena by up to ∼80%.
Multi-Disciplinary Simulation of Piezoelectric Driven Microfluidic Inkjet
Authors: Zeng Jun , Schmidt Charles G. , Liu Hui , Jilani Adel
Published: July 2010

Piezoelectric inkjet technology is critical to documentation, graphic arts and manufacturing applications. Physical modeling plays an essential role in the development of this technology. In this paper, we present a comprehensive, multi-level, inter-disciplinary simulation approach for piezoelectric inkjet design. This includes a high-fidelity, inter-disciplinary detailed simulation method for architecture investigation, and a much faster reduced-order modeling approach that enables interactive design of voltage waveforms. Simulation results are compared with experimental data. The multi-level inter-disciplinary simulation methodology presented here can be applied to designing MEMS and microfluidic devices and systems [1].
Concept and Modeling of a Statically Balanced Compliant Laparoscopic Grasper
Authors: Tolou Nima , Herder Just L.
Published: July 2010

The objective of this investigation is to present a concept as well as mathematical modeling and finite element modeling of a statically balanced compliant laparoscopic grasper. To obtain force feedback, the positive stiffness of the compliant grasper was statically balanced by a negative-stiffness compensation mechanism. The negative stiffness has been produced by pairs of pre-stressed initially-curved pinned-pinned beams out of linear elastic material, arranged perpendicular to the link driving the grasper. First, the conceptual design is explained. Subsequently, its behavior is mathematically formulated and then finite element modeling is implemented using a commercially available finite element modeling package. Finally, a stress-optimized design of a negative-stiffness compensation mechanism and the effect of parameter changes on the accuracy are obtained. The results illustrate the efficiency of the applied analysis methods for the case of statically balancing the laparoscopic grasper. It also demonstrates the efficiency of the balancer concept. The proposed procedure is found to be convenient for this set of problems, and can probably be applied to other similar practical problems.
Interdisciplinary Graduate Design Programs: Results and Recommendations From a NSF Workshop
Authors: Simpson Timothy W. , Hunter Samuel T. , Bryant-Arnold Cari , Parkinson Matthew , Barton Russell R. , Celento David , Messner John
Published: July 2010

Improving the creativity and innovativeness of U.S. graduate students is a mandate for national competitiveness and social well-being. Despite this imperative, many are uncertain about how to best prepare students for tackling the complex design problems of the future, some that we know about and others yet to be uncovered. With this in mind, we convened a two-day workshop at the National Science Foundation (NSF) in Arlington, VA to discuss the challenges, successes, and future directions for interdisciplinary graduate design programs that have recently emerged or are being established to address this critical need. Not including NSF personnel, 42 people from academia and industry gathered to learn about nine existing interdisciplinary design programs. Three panels were also held to discuss: (1) overcoming interdisciplinary differences in research and teaching, (2) industry perspectives on interdisciplinary design programs, and (3) future directions and program developments. A number of common themes emerged from the workshop, including the disciplinary characteristics of interdisciplinary design, the varying perspectives on the design process, pedagogical approaches toward teaching interdisciplinary design, structuring interdisciplinary design degrees, and sustainability of an interdisciplinary design discipline. Based on the dialogue at the workshop and our analysis of the common themes, we offer ten recommendations divided into three areas: (1) advance interdisciplinary design activities, (2) enhance interdisciplinary design programs, and (3) support interdisciplinary design research.
Comparison Study Between Probabilistic and Possibilistic Approach for Problems With Correlated Input and Lack of Input Statistical Information
Authors: Lee Ikjin , Choi Kyung K. , Noh Yoojeong
Published: July 2010

Due to expensive experimental testing costs, in most industrial engineering applications, only limited statistical information is available to describe the input uncertainty model. It would be unreliable to use an estimated input uncertainty model, such as distribution types and parameters including the standard deviations for the distributions, that is obtained from insufficient data for the design optimization. Furthermore, when input variables are correlated, we would obtain non-optimum design if we use the assumption of independency for the design optimization. In this paper, two methods for problems with lack of input statistical information — possibility-based design optimization (PBDO) and reliability-based design optimization (RBDO) with confidence level on the input model — are compared using a mathematical example and Abrams roadarm of an M1A1 tank. The comparison study shows that the PBDO could provide an unreliable optimum design when the number of samples is very small and that it provides an optimum design that is too conservative when the number of samples is relatively large. Furthermore, the optimum design does not converge to the optimum design obtained using the true input distribution as the number of samples increases. On the other hand, the RBDO with confidence level on the input model provides a conservative and reliable optimum design in a stable manner, and the optimum design converges to the optimum design obtained using the true input distribution as the number of samples increases.
Kinematics of a Prism-Type Translational Robot
Authors: Lee Chung-Ching , Lee Po-Chih
Published: July 2010

From the viewpoint of kinematics, a three-dof Prism-type pure translational parallel robot is presented for the development of automatic assembly devices and a regional structure of a six-dof hybrid parallel platform. First, we describe the structural properties of the robot and analyze its kinematic mobility. A pure translational motion is verified to exist through the well-known D-H symbolic notations and the coordinate-transformation-matrix technique. What follows are the forward, inverse kinematics analysis, and their closed-form solutions by the matrix algebra approach. For further confirmation of the correctness of derived equations, some numerical examples are also given. With the help of the analytical displacement kinematics, we identify the volume of workspace. At last, taking account of the 3×3 reduced Jacobian matrix provides the condition number and the identification of singularity of configuration is explored based on the direct and inverse kinematics Jacobian matrix.