bluuebunny/crossref_metadata_2025 huggingface dataset:
Identification of Systems of Arbitrary Real Order: A New Method Based on Systems of Fractional Order Differential Equations and Orthogonal Distance Fitting
Authors: Skovranek Tomas , Despotovic Vladimir
Published: July 2010

A new method for identification of systems of arbitrary real order based on numerical solution of systems of nonlinear fractional order differential equations (FODEs) and orthogonal distance fitting is presented. The main idea is to fit experimental or measured data using a solution of a system of fractional differential equations. The parameters of these equations, including the orders of derivatives, are subject to optimization process, where the criterion of optimization is the minimal sum of orthogonal distances of the data points from the fitting line. Once the minimal sum is found, the identified parameters are considered as optimal. The so called orthogonal distance fitting, known also under the names of total least squares or orthogonal regression is naturally used in the fitting criterion, since it is the most suitable tool for fitting lines and surfaces in multidimensional space. The examples illustrating the methods are presented in 2-dimensional and 3-dimensional problems.
Integration of Finite Element and Multibody Dynamics Models Using Gluing Algorithm
Authors: Ryu Geunsoo , Ma Zheng-Dong , Hulbert Gregory M.
Published: July 2010

This paper provides a method of the coupling multibody dynamics (MBD) and finite element (FE) codes to solve flexible multibody dynamics problems across a distributed simulation platform. The aim is to minimize the information exchange across the different platforms yet still obtain results of engineering accuracy. Many approaches for solving flexible multibody systems consisting of elastic and rigid components have focused on how the equations of motion for the flexible components can be formulated and combined with other component equations. We present a Partitioned Iteration Method (PIM), which can decouple the elastic deformation and rigid body motion of the flexible body by employing a CG-following floating reference frame. In the PIM, the global motion of a flexible body is expressed as a summation of the linearized elastic deformation measured in the CG-following reference frame and the motion of the reference frame and be solved in separated finite element and multibody dynamics solvers. The PIM is combined with the gluing algorithm and is used to solve multiple flexible bodies in a distributed simulation environment. It enables the use of independent simulation servers, where each server can run commercially available or research-based MBD and/or FE solvers. Examples are provided to demonstrate the performance of the new method and to show how to decouple and integrate a general flexible multi-body dynamics system.
Numerical Modeling of Contact Pressure in Vane Seals
Authors: Xie Liangxi , Kong Jianyi , Qian Li , Li Gongfa , Wan Xiaohong
Published: July 2010

The sealing contact pressure is one important parameter in evaluating the sealing performance of vane seals. The paper proposes a new numerical approximation method to calculate contact pressures in vane seals. The model considers the fact that the seal, made by the elastomeric rubber, is nearly incompressible and can’t be compressed in three principal directions at the same time. Being compressed in two of the three principle directions, e.g. in y and z directions, the seal expands in the third direction, namely, the x-direction. With reasonable results derived in the model, the width of the vane groove for the seal should be a little wider than the initial width of the seal. The results are in consistent with classical sealing theories and experiments on O-ring seals.
Shear Correction for Thin Plate Finite Elements Based on the Absolute Nodal Coordinate Formulation
Authors: Dmitrochenko Oleg , Mikkola Aki
Published: July 2010

This study is an extension of a newly introduced approach to account transverse shear deformation in absolute nodal coordinate formulation. In the formulation, shear deformation is usually defined by employing slope vectors in the element transverse direction. This leads to the description of deformation modes that, in practical problems, may be associated with high frequencies. These high frequencies, in turn, could complicate the time integration procedure, burdening numerical performance of shear deformable elements. In a recent study of this paper’s authors, the description of transverse shear deformation is accounted for in a two-dimensional beam element, based on the absolute nodal coordinate formulation without the use of transverse slope vectors. In the introduced shear deformable beam element, slope vectors are replaced by vectors that describe the rotation of the beam cross-section. This procedure represents a simple enhancement that does not decrease the accuracy or numerical performance of elements based on the absolute nodal coordinate formulation. In this study, the approach to account for shear deformation without using transverse slopes is implemented for a thin rectangular plate element. In fact, two new plate elements are introduced: one within conventional finite element and another using the absolute nodal coordinates. Numerical results are presented in order to demonstrate the accuracy of the introduced plate element. The numerical results obtained using the introduced element agree with the results obtained using previously proposed shear deformable plate elements.
Analysis of a Worn Multirecess Hydrostatic Journal Bearing System
Authors: Vijaya Kumar E. , Phalle Vikas M. , Sharma Satish C. , Jain S. C.
Published: July 2010

In recent times Hydrostatic journal bearings have received considerable amount of attention by the researchers on account of their excellent performance as compared to other class of bearings. The objective of the present paper is to presents an analysis of a four-pocket capillary-compensated worn hydrostatic journal bearing system. The FEM has been used to solve the Reynolds equation governing the flow of lubricant in the clearance space of a multirecess journal bearing system together with capillary restrictor flow equation as a constant. The bearing performance characteristics of a capillary compensated 4-pocket worn hydrostatic journal bearing have been presented for a wide range of values of external load and nondimensional wear depth parameters. The numerically simulated results of bearing characteristics parameters in terms of maximum fluid-film pressure, minimum fluid-film thickness, lubricant flow rate and fluid film reaction have been presented. The simulated results suggest that for an accurate prediction of bearing characteristics data it is essential to include the effect of wear in the analysis of the hydrostatic journal bearing system.
Vibration-Based Fault Diagnosis of Slurry Pumps Using the Neighborhood Rough Set Model
Authors: Zhao Xiaomin , Hu Qinghua , Lei Yaguo , Zuo Ming J.
Published: July 2010

Rough set has been widely used as a method of feature selection in fault diagnosis. The neighborhood rough set model can deal with both nominal and numerical features, but selecting the neighborhood size for its application may be a challenge. In this paper, we illustrate that using a single neighborhood size for all features may overestimate or underestimate a feature’s degree of dependency. The neighborhood rough set model is then modified by setting different neighborhood sizes for different features. The modified model is applied to fault diagnosis of slurry pump impellers. The chosen feature subsets generated by the modified rough set model can be physically explained by the corresponding flow patterns and generate higher classification accuracy than the original feature subsets and the feature subsets generated by the original rough set model.
A Virtual Vehicle Simulator Controlled by Networked Embedded Systems via LIN, CAN, and FlexRay
Authors: Seo Suk-Hyun , Kim Jin-Ho , Kwon Key Ho , Jeon Jae Wook , Hwang SungHo
Published: July 2010

This paper presents a virtual vehicle simulator for testing networked embedded systems. These days a vehicle can include up to one hundred electronic control units. These control units are connected via communication media in order to improve the performance of vehicles. However, it is not an easy process to test electronic control units in real vehicles. Thus, we propose a virtual simulation of a vehicle which is controlled by an embedded network system. The simulator provides the essential requirements necessary to accurately test networked embedded systems. The proposed simulator provides a three-dimensional (3D) modeled virtual vehicle which is controlled by multiple networked embedded systems that transmit information to the simulator via LIN, CAN, and FlexRay communication protocols. This simulator enables us to predict the vehicle’s dynamics and communication problems.
Analysis of Impulse Response of a Gel by Nonlinear Fractional Derivative Models
Authors: Fukunaga Masataka , Shimizu Nobuyuki
Published: July 2010

In the separated paper in this conference, we proposed two fractional derivative models for stress-strain relation of viscoelastic materials. In this paper, these models are tried to analyze the experimental results on impulse response of a gel. It is shown that one model reproduces well the impulse response to relatively small impact velocity, while the other explains the response to larger impact velocity. It is also shown that the empirical nonlinear fractional derivative model proposed by authors at FDA08 has nearly identical impulse response to one of the models.
Engineering System Fault Detection Using Particle Filters
Authors: Samanta B.
Published: July 2010

This paper presents an approach to machinery fault detection using particle filters (PF). The machine vibration signals are processed using morphological signal processing (MSP) to extract a novel entropy based health index (HI) characterizing the signal shape-size complexity. The evolution of HI is approximated as a nonlinear state space model using a computational intelligence (CI) technique. PF is used to estimate the progression of HI in presence of observation and process noise. The PF based approach is illustrated for estimation of state and parameters of a chaotic system. The feasibility of the approach is demonstrated through vibration dataset of a helicopter drive-train system gearbox. The results help understand the relationship of the system condition, the corresponding HI, the level of degradation and its progression in a stochastic environment using Bayesian learning.
The Intelligent Learning Control on Slide Position of Mechanical Crank Press
Authors: Zhao Hong , Zhao Shengdun
Published: July 2010

An iterative learning control strategy based on the expert knowledge is proposed in the slide position control of the mechanical press. The slide can be stopped on an accurate position at any point of the slide travel. The proposed strategy is more efficiency and accurate than the original inching operation method. A new computer control system is developed for the mechanical press. Experimental results are shown that the proposed control strategy on the press JH23-63 is effective.
Bearing Fault Diagnosis Based on Embedded Multiple Sensors
Authors: Shao Yimin , Ge Liang , Mechefske Chris K. , Fang Jieping
Published: July 2010

Multiple sensors embedded in a bearing not only allow for the collection of accurate information related to the bearing operational state, but may also provide data for fault detection and diagnosis by providing for multi-parameter signal collection. This paper presents a new multiple sensor arrangement that includes two vibration acceleration sensing devices, two speed sensing devices and two temperature sensing devices that more effectively facilitates on-line monitoring of bearing condition. Improved performance for fault diagnosis is proved by comparison with traditional methods of signal collection.
Dynamics of Non-Ideal Topology Transitions in Multibody Mechanical Systems
Authors: Font-Llagunes Josep M. , Ko¨vecses Jo´zsef
Published: July 2010

Mechanical systems with time-varying topology appear frequently in various applications. In this paper, topology changes that can be modeled by means of bilateral impulsive constraints are analyzed. We present a concept to project kinematic and kinetic quantities to two mutually orthogonal subspaces of the tangent space of the mechanical system. This can be used to obtain decoupled formulations of the kinetic energy and the dynamic equations at topology transition. It will be shown that the configuration of the multibody system at topology change significantly influences the projection of non-ideal forces to both subspaces. Experimental analysis, using a dual-pantograph robotic prototype interacting with a stiff environment, is presented to illustrate the material.
Vibration Analysis of the Self-Excited Vibration in the Rotor System Due to Ball Balancer
Authors: Inoue Tsuyoshi , Niimi Hideaki , Ishida Yukio
Published: July 2010

The ball balancer has been used as the vibration suppression device in rotor system. It has a superior characteristic that the vibration amplitude is reduced to zero at the rotational speed range higher than the major critical speed. However, the ball balancer may cause a self-excited vibration when the balls rotate in the balancer, and this self-excited vibration results in the large amplitude vibration. In this paper, the occurrence region and vibration characteristics of the self-excited vibration are investigated. The theoretical analysis is performed and a set of the fundamental equations governing the self-excited vibration is obtained. The influences of the parameters, such as, damping of the ball motion, ball mass, and radius of the ball orbit are explained. As the result, it is shown that the damping of the ball motion and the ball mass have the effect on decreasing the occurrence region of the self-excited vibration.
FEM Modelling and Experimental Verification of a Rotor System With a Open Crack
Authors: Inoue Tsuyoshi , Nagata Nobuhiro , Ishida Yukio
Published: July 2010

Continuous operation of rotating machinery with a rotor crack is a risk condition since the rotor crack grows rapidly and may fail causing a catastrophic accident. This paper develops the finite element model of the rotating shaft with an open crack. The natural frequencies and the resonance curves of such a rotor system with an open crack is investigated, and the concise and accurate modeling of the open crack element is discussed. The natural frequencies and the resonance curves of the experimental system are measured for various positions and depths of the open crack. By comparing both the theoretical and experimental results, the accuracy of the developed simple finite element model of the rotating shaft with an open crack is clarified.
Fractional Derivatives and Complex Modes of Vibration
Authors: Kuroda Masaharu
Published: July 2010

As described herein, we develop a method to obtain a fractional derivative response of a vibratory system with multiple degrees of freedom (DOF). To obtain fractional-order derivatives/integrals of dynamic response at a certain point on a structure presents technical difficulties because measurements of fractional-order derivative/integral responses in structural dynamics yield some implementation techniques. However, our method obviates special sensors with additional signal-conversion functions. Therefore, existing displacement and velocity sensors can work. Obtaining fractional derivative responses can be accomplished using three methods. Using any of the three methods, fractional states can be expressed with complex vibration modes, in which each point of the system oscillates with a phase that is different from “in-phase” or “out-of-phase.”
Imbalances in High Precision Cutting Machinery
Authors: Niebsch Jenny , Ramlau Ronny
Published: July 2010

In high precision cutting processes it is very important to have a highly balanced system in order to produce components in optical quality. Achieving the best possible balancing state is a time consuming process. Therefor the prediction of the influence of the balancing state on the surface quality of the component is desirable. On the other hand such a prediction model should enable us to compute an objective necessary balancing state for a desired surface quality and thus save balancing time. In this article we present a model of an high precision cutting experimental platform that describes vibrations of the platform caused by imbalances and forces from the cutting process. To compute imbalances from vibrational measurements, regularizations techniques for the solution of inverse and ill-posed problems are employed and presented.
A Method for Estimating Physical Properties of a Combined Bicycle and Rider
Authors: Moore Jason K. , Hubbard Mont , Kooijman J. D. G. , Schwab A. L.
Published: July 2010

A method is presented to estimate and measure the geometry, mass, centers of mass and the moments of inertia of a typical bicycle and rider. The results are presented in a format for ease of use with the benchmark bicycle model [1]. Example numerical data is also presented for a typical male rider and city bicycle.
Control Constraint Realization for Multibody Systems
Authors: Fumagalli Alessandro , Masarati Pierangelo , Morandini Marco , Mantegazza Paolo
Published: July 2010

This paper discusses the problem of control constraint realization applied to generic under-actuated multibody systems. The conditions for the realization are presented. Focus is placed on the tangent realization of the control constraint. An alternative condition is formulated, based on the practical observation that Differential-Algebraic Equations (DAE) need to be integrated using implicit algorithms, thus naturally leading to the solution of the problem in form of matrix pencil. The analogy with the representation of linear systems in Laplace’s domain is also discussed. The formulation is applied to the solution of simple, yet illustrative problems, related to rigid and deformable bodies. Some implications of considering deformable continua are addressed.
Symbolic Model Reduction for Interval-Valued Scenarios
Authors: Mikelsons Lars , Brandt Thorsten
Published: July 2010

In many cases, the quantitative relevance of physical effects for a given technical problem is not known a priori. This holds especially for the analysis of the dynamics. Adopted from nonanalog circuit design, in the last years symbolic model reduction techniques found their way towards mechatronic system modeling. Given a scenario (system inputs, initial values, parameters) and an error bound, symbolic model reduction reduces the detailed model to a less complex model, which is guaranteed to stay within predefined error bounds. However, presently symbolic reduction techniques deliver reduced models, which are only verified for a single scenario. For example a reduced vehicle model emerging from the reduction of a complex multibody vehicle model for a cornering maneuver with a small constant steering angle, is not verified to stay inside the error bounds for any other maneuver. In this contribution this drawback is addressed by the use of interval-valued scenarios.
Experimental Validation of the Lateral Dynamics of a Bicycle on a Treadmill
Authors: Kooijman J. D. G. , Schwab A. L.
Published: July 2010

In this paper, an experimental validation of the lateral dynamics of a bicycle running on a treadmill is presented. From a theoretical point of view, bicycling straight ahead on a treadmill with constant belt velocity should be identical to bicycling on flat level ground with constant forward speed. However, two major differences remain: first, stiffnesses of the contact of the tire with the belt compared to the contact on flat level ground; second, the belt velocity is fixed with respect to the world, irrespective of the change in heading of the bicycle on the treadmill. The admissibility of these two differences is checked by comparing experimental results with numerical simulation results. The numerical simulations are performed on a three-degree-of-freedom benchmarked bicycle model [1]. For the validation we consider the linearized equations of motion for small perturbations of the upright steady forward motion. This model has been validated experimentally in a previous work [2]. The experimental system consists of an instrumented bicycle without a rider on a large treadmill. Sensors are present for measuring the roll rate, yaw rate, steering angle, and rear wheel rotation. Measurements are recorded for the case in which the laterally perturbed bicycle coasts freely on the treadmill. From these measured data, eigenvalues are extracted by means of curve fitting. These eigenvalues are then compared with the results from the linearized equations of motion of the model. As a result, the model appeared to be accurate within the normal bicycling speed range, and in particular the transition from stable to unstable weave motion was very well predicted.
Lagrangian D’Alembert Modeled Maneuverable Autonomous Non-Holonomic Mobile Robot Using a Closed Loop PD Controller
Authors: Georgiou E. , Dai J.
Published: July 2010

The motivation for this work is to develop a platform for a self-localization device. Such a platform has many applications for the autonomous maneuverable non-holonomic mobile robot classification, which can be used for search and rescue or for inspection devices where the robot has a desired path to follow but because of an unknown terrain, the device requires the ability to make ad-hoc corrections to its movement to reach its desire path. The mobile robot is modeled using Lagrangian d’Alembert’s principle considering all the possible inertias and forces generated, and are controlled by restraining movement based on the holonomic and non-holonomic constraints of the modeled vehicle. The device is controlled by a PD controller based on the vehicle’s holonomic and non-holonomic constraints. An experiment was setup to verify the modeling and control structure’s functionality and the initial results are promising.
A Pendulum Actuator and Its Force Generation Capabilities
Authors: May Chris , Janocha Hartmut , Grasso Emanuele , Naso David
Published: July 2010

This paper presents the construction and properties of a so-called pendulum actuator used for generating dynamic forces. The discussion illustrates that this type of actuator can potentially cover a wide field of applications. Generating harmonic force signals, however, demands special provisions due to the inherent non-linear kinematics of the actuator device. The paper explains the selected measures and presents the achieved results.
Reliability-Based Design of Future Highly Reliable Systems
Authors: Junglas Marco , Kazeminia Amir , Eick Ru¨diger , So¨ffker Dirk
Published: July 2010

This paper focuses on mechatronic systems reliability assessment during the development process phases. Modern technical systems safety requirements are regulated by law, especially the level of safety relevant systems or components. This means it is necessary to decide at early design phase which topology or hardware suites the safety requirements of the system. Therefore the first step is to detect the system impact factors, model the system architecture, and generate a topology tree. One possibility to describe the system architecture is given by the use of the Unified Modeling Language (UML). From the system architecture descriptions MATLAB/Simulink models can be generated. Subsequently the next step is the realization of a reliability-oriented topology, which can be used to consider reliability-oriented aspects.
Product Lifecycle Management: A Survey
Authors: Liu Wei , Zeng Yong , Maletz Michael , Brisson Dan
Published: July 2010

This paper presents an overview of the field of Product Lifecycle Management (PLM). Though PLM has many facets, this paper mainly focus on the business drivers, requirements, concept and components behind the PLM as well as the technical foundations and the status of PLM academic research and industry solutions. Furthermore, a holistic roadmap of PLM is presented. The future research trends and challenges are finally discussed.
System-Level Modal Representation of Flexible Multibody Systems
Authors: Heirman Gert H. K. , Desmet Wim
Published: July 2010

The presence of both differential and algebraic equations in the model equations, as well as the number of degrees of freedom needed to accurately represent flexibility, prohibit fast simulation of flexible multibody systems (e.g. real-time). In this research, Global Modal Parametrization, a model reduction technique for flexible multibody systems is further developed to speed up simulation of flexible multibody systems. The reduction of the model is achieved by projection on a curvilinear subspace instead of a fixed vector space, requiring significantly less degrees of freedom to represent the system dynamics with the same level of accuracy. The complexity of simulation of the reduced model equations is estimated. In a numerical experiment, simulation results for the original model equations are compared with simulation results for the model equations obtained after model reduction, showing a good match. The dominant sources of error of the proposed methodology are illustrated and explained.
Vibration Signature Analysis of a Rotor Bearing System Using Response Surface Method
Authors: Kankar P. K. , Sharma Satish C. , Harsha S. P.
Published: July 2010

The vibration response of a rotor bearing system is extremely important in industries and is challenged by their highly non-linear and complex properties. This paper focuses on performance prediction using response surface method (RSM), which is essential to the design of high performance rotor bearing system. Response surface method is utilized to analysis the effects of design and operating parameters on the vibration response of a rotor-bearing system. A test rig of high speed rotor supported on rolling bearings is used. Vibration response of the healthy ball bearing and ball bearings with various faults are obtained and analyzed. Distributed defects are considered as surface waviness of the bearing components. Effects of internal radial clearance and surface waviness of the bearing components and their interaction are analyzed using design of experiment (DOE) and RSM.
Vibratory Mobilization of Two-Phase Liquid Trapped in Capillary
Authors: Cheng Gang , Dai Liming
Published: July 2010

The newly developed Enhanced Oil Recovery technology implementing vibration and seismic stimulations relies on mobilization of oil trapped in pores of porous media of reservoir. This research indents to investigate the conditions for dynamically mobilizing an oil slug trapped in capillary with controlled vibration. An idealized physical model is established, on which series of experimental tests are performed for determining the conditions. Initiation of the mobilization and the effects of vibration frequency and duration of vibration on the mobilization are analyzed. The results of the research are significant for reveal the mechanism of Enhanced Oil Recovery technology with vibro-seismic stimulation.
Evaluation of the Effect of Paint Degradation on Shipboard Impressed Current Cathodic Protection Performance: A Physical Scale Modeling Approach
Authors: Wang Yueping , KarisAllen Ken J.
Published: July 2010

Physical scale modeling (PSM) has been used to evaluate and design shipboard impressed current cathodic protection (ICCP) systems in several NATO countries. With the application of numerical modeling techniques for the evaluation of shipboard ICCP performance, efforts to validate numerical modeling results using PSM data have been gaining increasing importance. As part of the efforts, a discrete area current control (DACC) technique was developed in previous studies to simulate the polarization resistance behavior of multiple cathodes including nickel aluminum bronze propellers and paint damage areas under a variety of conditions. The application of the DACC technique facilitated the use of identical polarization resistance data as boundary conditions for both PSM and numerical modeling analyses in the validation studies. In the current work, the DACC technique was extended to simulating polarization resistance behavior of various paint degradation scenarios (with polarization resistances varying from 1×107 Ωcm2 to 2×105 Ωcm2) to study the effect of paint degradation on the performance of a shipboard ICCP system. The results indicated that overall paint degradation does not significantly affect the hull potential profile until the magnitude of the polarization resistance of the paint coating decreases below 1×107 Ωcm2. The PSM profiles were also compared with numerical modeling data acquired using a boundary element code resulting in a good agreement between the two techniques. The discrepancies observed between the PSM and numerical modeling profiles have also been discussed.
Efficient Analysis of 3-D Plates via Algebraic Reduction
Authors: Mishra Vikalp , Suresh Krishnan
Published: July 2010

3-D finite element analysis (3-D FEA) is not generally recommended for analyzing thin structures such as plates and shells. Instead, a variety of highly efficient and specialized 2-D numerical methods have been developed for analyzing such structures. However, 2-D methods pose serious automation challenges in today’s 3-D design environment. In this paper, we propose an efficient yet easily automatable 3-D algebraic reduction method for analyzing thin plates. The proposed method exploits standard off-the-shelf finite element packages, and it achieves high computational efficiency through an algebraic reduction process. In the reduction process, a 3-D plate bending stiffness matrix is constructed from a 3-D mesh, and then projected onto a lower-dimensional space by appealing to standard 2-D plate-theories. Algebraic reduction offers the best of both worlds in that it is computationally efficient, and yet easy to automate. The proposed methodology is substantiated through numerical experiments.
Flatness Based Control and Model Predictive Trajectory Generation for Boom Cranes
Authors: Neupert Joerg , Arnold Eckhard , Knierim Lukas , Sawodny Oliver , Schneider Klaus
Published: July 2010

The main control tasks for automation of crane operation are load sway damping and load velocity tracking control. A non-linear dynamic crane model combines the equations of motion of the rope suspended load and approximations of the actuator dynamics. Using the flatness property of the crane model, a non-linear controller is obtained by feedback linearization. Smooth and feasible reference trajectories are generated as solutions of an optimal control problem. The control system is implemented at a LIEBHERR harbor mobile crane. Measurement results show the validity of the approach.
A Formal Representation of Software-Hardware System Design
Authors: Walkingshaw Eric , Strauss Paul , Erwig Martin , Mueller Jonathan , Tumer Irem
Published: July 2010

The design of hardware-software systems is a complex and difficult task exacerbated by the very different tools used by designers in each field. Even in small projects, tracking the impact, motivation and context of individual design decisions between designers and over time quickly becomes intractable. In an attempt to bridge this gap, we present a general, low-level model of the system design process. We formally define the concept of a design decision, and provide a hierarchical representation of both the design space and the context in which decisions are made. This model can serve as a foundation for software-hardware system design tools which will help designers cooperate more efficiently and effectively. We provide a high-level example of the use of such a system in a design problem provided through collaboration with NASA.
An Experimental Investigation of State-Variable Modal Decomposition Method for Modal Analysis
Authors: Farooq Umar , Feeny Brian F.
Published: July 2010

This work presents the experimental evaluation of the statevariable modal decomposition (SVMD) method for modal parameter estimation of multi degree-of-freedom (MDOF) vibration systems. Using output response ensembles only, the generalized eigenvalue problem is formed to estimate eigen frequencies and modal vectors for a lightly damped linear clamped-free experimental Euler beam. The estimated frequencies and modal vectors are compared against the theoretical system frequencies and modal vectors. Satisfactory results are obtained for estimating both system frequencies and modal vectors for the first five modes. To validate the actual modes from the spurious ones, modal coordinates are employed that together with frequency and vector estimates substantiate the true modes. The paper also addresses the error associated with estimation when the number of sensors is less than the active/dominant modes of the system shown via a numerical example.
A Framework for Early Assessment of Functional Failures to Aid in PHM Design
Authors: Kramer Scott , Tumer Irem
Published: July 2010

Human artifacts have evolved into incredibly complex systems that rely on both hardware and software to function dependably with limited or no human operator control. As the monetary and human consequences for failure climb with technological progress, Prognostic and Health Management (PHM) systems are developed to help manage, mitigate, detect, and respond to failures. These PHM systems have become as integral and as important as any other subsystem in a complex machine. Methods have been developed to analyze and incorporate risk and reliability in the early stage decision making processes of complex system design. These methods, however, treat the development and capabilities of PHM in the conceptual stage of system design in a peripheral manner at best. The importance of PHM consideration early in system design is significant. The structure of PHM, one of the most complex of the subsystems, can begin to take shape. Design modifications that must be made in light of PHM limitations should be pushed to the earliest stage of design possible, where costs of changes are minimized. In this paper, several risk and reliability based design techniques are discussed in this context. In particular Function Failure Identification Propagation framework (FFIP) provides a systematic process to identify potential failure points and their resulting functional losses. FFIP is selected in this paper as fitting early stage PHM development very well. However, improvements are proposed to the existing FFIP process to better address PHM design needs during the conceptual design stage of a complex system. This paper presents an improved method, which is then applied to a liquid fueled rocket engine architecture. Future work, including using the information gathered here to start the conceptual design of the PHM system, is also discussed.
Development of Wood Grain Pattern Design System
Authors: Shibasaki Satoshi , Aoyama Hideki
Published: July 2010

Various approaches for generating woodgrain patterns using computer graphics have been proposed so far. However, the generation of various woodgrain patterns with conventional methods is difficult due to the need for the adjustment of numerous parameters to express a real woodgrain pattern. In this paper, a new mathematical approach for generating woodgrain patterns is proposed. Virtual trees are generated by simulating tree growing based on past actual weather information obtained from public organizations, and woodgrain patterns are then acquired by cutting the trunks of the virtual trees. In order to simulate tree growing, growth models of tree are constructed in consideration of dendrological characteristics and environmental conditions. Growth of tree is influenced by various environmental factors, such as sunlight, temperature, carbon dioxide concentration, wind, precipitation, soil nutrient, inclination of ground, survival amongst surrounding trees, etc. With this system, the growth model of trees is constructed based on precipitation, temperature, sunlight, and inclination of ground, which especially have strong effects on tree growth. With this approach, various types of virtual trees can be obtained by changing growth conditions such as period and location of growth without the need to reset complicated parameters of tree species, and then the virtual trees can be cut at arbitrary areas, thus allowing a variety of woodgrain patterns to be easily generated by one parameter setup.
3D Predictive Model for Controlled Resistance Welding of Composites for Manufacturing Applications
Authors: Zammar Imad , Mantegh Iraj , Ahmadi Mojtaba
Published: July 2010

A three-dimensional transient heat transfer model is developed for a sequential joining process (resistance welding) applied on thermoplastic composites. This process involves with moving a voltage source along a heating element that conducts the power throughout a resistive mesh, generating heat and melts and bounds two composite surfaces. The model developed here is used to predict the spatial and temporal variations in the current and temperature over the weld seam for different set of input variables. The model integrates both the resistive and thermal behaviours of components involved. The significance of this modeling approach is that it captures the movement of the electrical connection, simulating a sequential joining process along a continuous weld seam. The modeling results are compared with experimental data obtained by thermocouples and infrared camera, and accurately predict the trend of variations in weld temperature.
Reliability Prediction Methods: A Survey and Selection for Mechanical Design-For-Reliability
Authors: Huang Zhaofeng , Jin Yan
Published: July 2010

There are many reliability prediction methods applicable to mechanical systems design. This paper specifically discusses the methods of probability or failure rate generation for reliability prediction. The paper consists of three parts. The first part is to survey the methods. We survey five most frequently used failure probability generation methods: statistical frequency and modeling method, similarity and comparative assessment method, physics based failure modeling, Monte Carlo simulation, and expert elicitation. We discuss the technical rationale and scientific foundation of each method and illustrate them with application examples. The second part is to evaluate and compare the methods. We identify the following attributes for evaluating and ranking the methods: the closeness of the method to the design; the validity and fidelity of the prediction results; the extensiveness of the analysis effort involved and data needs; the applicability of the methods at different product life cycle stages; and the limitations and cautions of using the prediction results to assist design-for-reliability. The third part is to establish a selection framework from applicable methods based on the ranking result of the second part, to assist practical use of the methods for mechanical design-for-reliability.
PMT: Modeling Enterprise Operations and Organizations
Authors: Yahyaei Majid , Suzuki Yoichiro , Jin Yan
Published: July 2010

Enterprise environments are complex and multidisciplinary. As the market competition becomes more and more relentless, business companies must keep adapting their current processes to the new needs of the market. During the adaptation process, enterprises may not have any experience with the new business needs. Many enterprise models from different perspectives have been proposed to facilitate this adaption process and reduce risks. However, due to the complexity of the enterprise environment, none of them takes all needed enterprise elements into consideration. A uniform approach that deals with different elements of an enterprise is needed in order to model all elements and analyze their effects on enterprise operations. Inspired by Galbraith’s information processing view of organizations and the extant modeling work of project organizations, in this paper we propose a unique model of enterprise called PMT that can be used to analyze enterprise operations and their interactions with market demands. Market demand as an independent variable and enterprise capacity (organization, processes and resources) are modeled computationally and the relations between them are captured. In this paper, the background and the major concepts of the PMT model are introduced and an application example demonstrated to show the effectiveness of the PMT model.
Chaotic Dynamics in a Higher-Dimensional Nonlinear System for a Composite Laminated Plate
Authors: Zhang Wei , Gao Mei-juan
Published: July 2010

In this paper, we first analyze the chaotic dynamics of a higher-dimensional nonlinear system for a composite laminated plate in the case of 1:3:3 internal resonances with the theory of normal form and the energy-phase method. The theory of normal form is used to obtain the simpler normal form of the system. The energy-phase method is employed to analyze the multi-pulse chaotic dynamics of the higher-dimensional nonlinear system for a composite laminated plate. Moreover, the numerical simulation is performed to find the multi-pulse chaotic motion of the composite laminated plate. The global theory analysis and the results of numerical simulation demonstrate that the existence of the periodic motions and chaotic motions with the jumping phenomena in the composite laminated plate.
Performance Evaluation of Real-Time Kinematic GPS at Arctic Latitudes
Authors: Salerno Alessio , Lamarche Tom , Dupuis Erick
Published: July 2010

A real-time kinematic (RTK) global positioning system (GPS) has been identified for potentially being used as a ground-truth sensor for testing robotic rovers for planetary exploration. A series of environmental tests needs to be performed in order to validate the performance of the sensor at hand before being used as a ground-truth system. This paper focuses on the performance evaluation of the RTK GPS at Axel Heiberg Island Canadian Space Agency’s Analogue Research Network (CARN) site. This is one of the officially recognized terrestrial analogues, that is places on Earth that approximate the geological, environmental and putative biological conditions on Mars and other planetary bodies (Hipkin et al.). The challenge lies in the use of the equipment at Arctic latitudes. The results show that the system performed according to specifications even in this challenging environment.
Developing Evolving Machines for Creative Customers
Authors: Fukuda Shuichi
Published: July 2010

Realizing good quality as a final product has been our traditional approach to machine design. Therefore, current machines are provided with a wide range of full fledged functions. But the higher the function levels become and the more complex a machine becomes, the more our customers feel uneasy. Traditional reliability deals with the issue of verification. i.e., “Are we making the product right?” But what we should ask ourselves in this age of frequent and extensive changes is “Are we making the right product?” This is the issue of validation. We have to consider how we can satisfy our customers’ expectations to really gain their trust. Machines become too much complex so our customers do not know what to expect. We have to give a clear message to our customers what to expect and how their expectation will be satisfied. If we could evolve our machines’ functions step by step just as in software, our creative customers would become happier because they would know what to expect so that they can enjoy “customizing” their products to their current needs and to their tastes. Our customers could share their experience and share their stories with their friends. Such adaptive maintenance will satisfy the human needs pointed out by Maslow and would produce a greater life time value than a one time value we produce as a final product.
Obstacle Avoidance in Simulated Environment Using Eye Tracking Technologies
Authors: Antonya Csaba , Barbuceanu Florin , Rusa´k Zolta´n , Talaba Doru , Butnariu Silviu , Erde´lyi Hunor
Published: July 2010

The paper is investigating the relationship between human eye movements, correlated with the visual perception of computer generated scene on one hand and obstacle avoidance strategies on the other hand, during the process of driving a computer game-like car. Several issues were investigated regarding how the gaze fixation point of the driver is moving during obstacle avoidance maneuvers. The relevance of each issue in making a decision was assessed. The main goal is to establish a correlation (mapping) system between gaze fixation parameters and obstacles avoidance strategies in order to be able to develop cognitive algorithms for driver assistance in real world driving conditions, to monitor driver’s vigilance and ultimately to enable progress towards the autonomous vehicle which can avoid possible obstacles or resolve hazardous traffic situations just by monitoring the eye movements of the driver.
Robotic Networks in Applied Distributed Mechatronics Systems: Problems and Issues in Developments and Applications
Authors: Sanaatiyan M. M. , Hassanpour Hamid
Published: July 2010

Most of classical robot systems are constructed by using a monolithic system with a predefined physical layout, unified model of programming and operation. There are, however, a number of tasks that can’t be solved with such systems or the use of a single system limits the performance. So, we think Distributed Mechatronic Systems are the most reasonable solution in the applied projects. Network Robotics, Multiagent Mobil Systems, Network Robotic Systems which usually uses sensors/actuators networks can be an applied approach to deploy some of the Distributed Mechatronic Systems. Some of the most important applied projects have been surveyed. Therefore, we have found there are too many bottleneck and challenges in Distributed Mechatronic Systems and they will be discussed in this paper.
Numerical Simulation of NO Production in Gas-Turbine Combustor With Large-Eddy Simulation Using 2-Scalar Flamelet Approach
Authors: Nishida Shingo , Yamamoto Tomonori , Tsukamoto Kazuhiro , Oshima Nobuyuki
Published: July 2010

Under high temperature combusting environment, very high level of thermal NOx is generated. In order to prevent environmental contamination and pursue more power generation efficiency, we need to build up radically new combustion mode that satisfies both of higher temperature at outlet and lower NOx emissions. To investigate the ability of our numerical prediction method in a practical combustor system, we calculate two combustion modes and predict time-averaged temperature and NOx distribution in the 1700degC class gas-turbine combustor that is a test model fabricated by Mitsubishi Heavy Industries, Ltd. Then, we compare with experimental data to validate and analyze our calculation model. The results show LES and 2-scalar flamelet approach is very effective to predict NOx production in practical gas-turbine combustor.