bluuebunny/crossref_metadata_2025 huggingface dataset:
A Swarm Engineering Approach to Mobile Sensor Network Design Towards Collaborative Phototaxis With A Slowly Moving Light Source
Authors: Bourgeous William , Rounds Shelley , Chen YangQuan
Published: May 2009

Swarm robotics is an innovative approach to the control and coordination of multi-agent systems that use naturally inspired swarm intelligent methods to perform tasks. A swarm based approach can decrease the complexity and the cost of designing a cooperative multi-robot system. This paper proposes a general engineering approach to develop a robotic swarm that focuses on how to synthesize an emergent behavior and the associated inputs to this end. We validate our methodology by engineering a swarm to simultaneously rendezvous on a stationary light source. Furthermore, we also considered the case when the light source is slowly moving. The design is simulated in NetLogo, an agent-based modeling software, and implemented on the MASnet robot platform. This work demonstrates the basic knowledge and tools required to engineer a robotic swarm.
A Robust Control Design Approach Combining Exact Linearization and High-Gain PI-Observer
Authors: Liu Yan , So¨ffker Dirk
Published: May 2009

This paper introduces a robust nonlinear control method combining classical feedback linearization and a high-gain PI-Observer (Proportional-Integral Observer) approach that can be applied to control a nonlinear single-input system with uncertainties or unknown effects. It is known that the lack of robustness of the feedback linearization approach limits its practical applications. The presented approach improves the robustness properties and extends the application area of the feedback linearization control. The approach is developed analytically and fully illustrated. An example which uses input-state linearization and PI-Observer design is given to illustrate the idea and to demonstrate the advantages.
Estimating Haul Truck Dutymeters Using Operational Data
Authors: Mechefske Chris K. , Campbell Curtis
Published: May 2009

Modern mobile mining equipment is becoming increasingly more instrumented in an effort to reduce operating costs through production and operation monitoring. This provides access to large amounts of data, primarily related to machine operation, not previously available. This work examines applicable operational loading parameters, and their relationship to haul truck component reliability. The Cox proportional hazards model was used to determine which parameters were strongly related to hoist cylinder and final drive reliability. These “dutymeters” can then be used to optimize particular aspects of the maintenance program, specifically to indicate the feasibility of component utilization beyond current replacement benchmarks. Components that have been lightly loaded throughout their operational life, as indicated by the defined dutymeters, could qualify for extended use with a greater chance of reliability.
Periodic and Chaotic Oscillations of an Axially Moving Viscoelastic Belt in Three-Dimensional Space
Authors: Zhang Wei , Liu Yan-Qi , Chen Li-Hua , Yao Ming-Hui
Published: May 2009

Periodic and chaotic space oscillations of an axially moving viscoelastic belt with one-to-one internal resonance are investigated for the first time. The Kelvin viscoelastic model is introduced to describe the viscoelastic property of the belt material. The external damping and internal damping of the material for the axially moving viscoelastic belt are considered simultaneously. The nonlinear governing equations of motion of the axially moving viscoelastic belt for the in-plane and out-of-plane are derived by the extended Hamilton’s principle. The method of multiple scales and Galerkin’s approach are applied directly to the partial differential governing equations of motion to obtain four-dimensional averaged equation under the case of 1:1 internal resonance and primary parametric resonance of the first order modes for the in-plane and out-of-plane oscillations. Numerical method is used to investigate periodic and chaotic space motions of the axially moving viscoelastic belt. The results of numerical simulation demonstrate that there exist periodic, period-2, period-3, period-4, period-6, quasiperiodic and chaotic motions of the axially moving viscoelastic belt.
Integral Building Design Workshops: A Concept to Structure Communication
Authors: Savanovic Perica , Zeiler Wim
Published: May 2009

Following the developments in (Dutch) building practice, where besides specialist skills a design approach is increasingly being asked, the Building Services chair of the Faculty of Architecture, Building and Planning of Technische Universiteit Eindhoven (TU/e) initiated in academic year 2005/06 a multidisciplinary masters project ‘Integral Design’. In this first edition, architecture, building technology and building services students participated. As basis for this project served a learning-by-doing workshop approach, developed and tested with/on experienced practitioners from the Royal Institute of Dutch Architects (BNA) and the Dutch Association of Consulting Engineers (ONRI). The (theoretical) background for the workshops is provided by two PhD projects running within KCBS, entitled ‘Integral design methodology in the context of sustainable comfort systems’ and ‘Integral design methodology in the context of collaborative engineering’. KCBS stands for Knowledge Centre for Building and Systems TNO-TU/e, cooperation between the Netherlands Organization for Applied Scientific Research – core area Built Environment and Geosciences and TU/e. In this paper the results of the first multidisciplinary masters project edition are discussed. At the same time a comparison with BNA-ONRI-KCBS workshops for practitioners is made. The conclusions of this analysis helped us to define improvements for 2006/07 edition of ‘Integral Design’ multidisciplinary masters project, which will take place in the first half of year 2007.
Parametric Instability of a Rotating Circular Ring With Moving, Time-Varying Springs
Authors: Vangipuram Canchi Sripathi , Parker Robert G.
Published: May 2009

Parametric instabilities of in-plane bending vibrations of a rotating ring coupled to multiple, discrete, rotating, time-varying stiffness spring-sets of general geometric description are investigated in this work. Instability boundaries are identified analytically using perturbation analysis and given as closed-form expressions in the system parameters. Ring rotation and time-varying stiffness significantly affect instability regions. Different configurations with a rotating and non-rotating ring, and rotating spring-sets are examined. Simple relations governing the occurrence and suppression of instabilities are discussed for special cases with symmetric circumferential spacing of spring-sets. These results are applied to identify possible conditions of ring gear instability in example planetary gears.
Structured Vibration Modes of General Compound Planetary Gear Systems
Authors: Kiracofe Daniel R. , Parker Robert C.
Published: May 2009

This paper extends previous analytical models of simple, single-stage planetary gears to compound, multi-stage planetary gears. This model is then used to investigate the structured vibration mode and natural frequency properties of compound planetary gears of general description, including those with equally-spaced planets and diametrically opposed planet pairs. The well-defined cyclic structure of simple, single-stage planetary gears is shown to be preserved in compound, multi-stage planetary gears. The vibration modes are classified into rotational, translational, and planet modes and the unique properties of each type are examined and proved for general compound planetary gears. All vibration modes fall into one of these three categories. For most cases, both the properties of the modes and the modes themselves are shown to be insensitive to relative planet positions between stages of a multi-stage system.
The High Dimensional Harmonic Balance Analysis of a Second-Order Delay-Differential Equations
Authors: Liu Liping , Kalma´r-Nagy Tama´s , Dowell Earl H.
Published: May 2009

In this paper we demonstrate the utility of the High Dimensional Harmonic Balance (HDHB) method to compute periodic orbits of second-order delay-differential equations. In particular, the method has been successfully applied to capture the unstable limit cycles of a model of regenerative machine tool vibrations. Both the conventional harmonic balance and the HDHB methods are employed to investigate the dynamic behavior of the nonlinear delay equation. The results show an excellent agreement with those from time domain solutions. The advantages of HDHB over the classical Harmonic Balance method are highlighted and discussed.
Biomechanical Applications of Computers in Engineering Education
Authors: Schonning Alexandra
Published: May 2009

This paper discusses integration of biomechanical research in the undergraduate mechanical engineering curriculum. The projects presented emphasize the use of computers and computer-aided engineering software. Two different projects are discussed. The first project involves generation of three-dimensional computer models of the bones of the lower limb, and the second project the generation of three-dimensional computer models of the shoulder to be used in developing an implant. Through these projects the students learned specialized computer-aided engineering software tools and also enhanced their communication skills through technical report writing and presenting a paper at a conference.
Development of Extended Wheelchair Operation Observer to Estimate Precise Two-Dimensional Tilt Information
Authors: Oh Sehoon , Hori Yoichi
Published: May 2009

An operation states observer for a wheelchair system is extended to three dimensions in this paper. This new observer incorporates a three-axis accelerometer allowing a user to estimate more precise information on terrain condition. To design this observer, first, a model dynamics illustrating the two-dimensional relationship between the gravity and the motion of a wheelchair on a slope is derived. Experimental results verify our derivation of equations. Then, the dynamics is simplified and used in the design of the extended observer. Since the dynamics itself and the output of that have nonlinear characteristics, the extended kalman filter design algorithm is employed. By simulation, the stability and effectiveness of the application is verified.
Stability Analysis of Two-Layered Finite Hydrodynamic Porous Journal Bearing Using Linear and Nonlinear Transient Method
Authors: Kakoty S. K. , Laha S. K. , Mallik P.
Published: May 2009

A theoretical analysis has been carried out to determine the stability of rigid rotor supported on two symmetrical finite two-layered porous oil journal bearings. The stability curves have been drawn for different eccentricity ratios and Sommerfeld numbers. The effect of bearing feeding parameter, L/D ratio on the stability is also investigated. This paper also deals with a theoretical investigation of stability using a non-linear transient method. This analysis gives the journal centre locus and from this the system stability can be determined. With the help of graphics, several trajectories of the journal centre have been obtained for different operating conditions. Finally a comparison between single-layered porous bearing and the two-layered porous bearing is presented here.
Optimal Design of Steering Mechanisms in Road Vehicles
Authors: Sancibrian Ramon , De-Juan Ana , Garcia Pablo , Viadero Fernando , Fernandez Alfonso
Published: May 2009

This paper deals with the design of steering mechanisms in road vehicles. With this aim, the kinematic models of three types of steering linkages are considered and Ackermann steering geometry is used to define the objective function. The proposed method uses a dimensional synthesis technique based on local optimization to obtain the dimensions of the links. The problem is formulated as function generator synthesis, where the inner wheel is supported by the input link and the output link is supported by the outer wheel. The formulation presented in this paper was developed by the authors and it is capable of considering the necessary accuracy conditions in the design of this kind of linkage. Three examples are shown to illustrate the application of the method.
A Study of Life Cycle Costing in the Perspectives of Research and Commercial Applications in the 21st Century
Authors: Cheung Wai M. , Newnes Linda B. , Mileham Antony R. , Marsh Robert , Lanham John D.
Published: May 2009

This paper presents a review of research in the area of life cycle costing and offers a critique of current commercial cost estimation systems. The focus of the review is on relevant academic research on life cycle cost from 2000 onwards. In addition to this a comparison of the current cost estimation systems is presented. Using the review findings and industrial investigations as a base, a set of mathematical representations for design and manufacturing costs and the introduction of the critical factors is proposed. These are considered in terms of the operational, maintenance and disposal costs to create a method for ascertaining the life cycle cost estimate for complex products. This is presented using as an exemplar, research currently being undertaken in the area of low volume and long life electronic products in the UK defence sector. The benefit of the method proposed is that it aims to avoid the inflexibility of traditional approaches which usually require historical and legacy data to support the cost estimation processes.
Research on Dynamic Characteristics of a Magnetorheological Damper With Decoupling Mechanism
Authors: Tu Fengchen , Chen Zhaobo , Li Hua , Jiao Yinghou , Li Mingzhang , Huang Wenhu
Published: May 2009

Satellites are subject to severe vibrations during flight. These vibrations are induced by multiple sources during liftoff and the instant of final separation. Severe vibrations may cause damage to satellites. For this reason a payload adaptor is needed. Magnetorheological (MR) damper can be utilized to keep the satellites safe. But the common MR damper can’t be used in cases of high-frequency vibrations because of stiffness hardening. For this reason, a new MR damper with decoupling mechanism has been designed by adding a decoupling sheet to the common MR damper. The decoupling mechanism makes the damper sensitive to vibration. This means that the damper has different stiffness and damping in case of different vibration amplitude. Based on the Bingham model, the model of the suggested MR damper has been built, and mathematical formulas has been deduced for dynamic stiffness, delay angle and transmissibility of the damper. Dynamic characteristics have been simulated. The results show that the decoupling sheet doesn’t work in case of low frequency and high amplitude vibration and the damper presents high damping. In case of high frequency and low amplitude vibration, the decoupling sheet works and the damper presents small damping and stiffness. Thus the stiffness hardening has been avoided. Influence of internal sub structure resonance can be reduced by choosing appropriate parameters. This damper can be used for semi-active control of broadband vibration.
Computational Steering of Interactive and Distributed Virtual Reality Applications
Authors: Lietsch Stefan , Zabel Henning , Berssenbruegge Jan
Published: May 2009

In this paper we present a system that transfers the well-known computational steering paradigm to interactive and distributed Virtual Reality applications. Those are often used in areas like rapid prototyping and all kinds of vehicle simulation. The distribution has many different purposes and affects various subsystems of a VR application. Most of the currently existing systems are very specialized and have a proprietary design for data-exchange and coupling of the components. We propose a more flexible approach by designing a computational steering framework that is well-adapted to the needs of highly interactive and distributed VR systems. Thereby we achieve higher reusability and scalability for the steering component itself as well as the possibility to exchange and compare subsystems. As a proof-of-concept we adapted an existing driving simulator to the proposed computational steering framework and discuss the advantages and difficulties in the second part of the paper.
Model Reference Adaptive System for the Noise Control of an Active Piezoelectric Acoustic Box
Authors: Nestorovic´ Tamara , Lefe`vre Jean , Gabbert Ulrich
Published: May 2009

A complex problem of the active structural acoustic control is considered in this paper from the controller design point of view in order to develop a suitable technique for the noise attenuation in a specific domain of a studied active structure – acoustic box attached with piezoelectric actuators and sensors. The model reference adaptive controller is developed based on the information and parameters of the active structure, contained in a state space model obtained through a finite element modeling procedure. The parameters of the reference model were selected based on the investigations of the closed-loop behavior of the control system with an optimal LQ controller in order to meet the requirements of the properly prescribed desired behavior of the controlled system. The model reference adaptive control system for the acoustic box was designed in a discrete-time domain. Model based simulation results show the reduction of the air pressure at a selected point of the actively controlled acoustic box in the presence of considered periodic excitations.
An Intelligent and Efficient Tree Search Algorithm for Computer-Aided Component Selection
Authors: Tamhankar Manasi , Campbell Matthew I.
Published: May 2009

Component selection in engineering design is a process in which an assembly of pre-defined component types is given and a choice of specific components is desired that satisfies a set of design requirements and constraints. Although algorithmic approaches to component selection have been researched for specific mechanical engineering problems such as bearing selection, a generalized technique has not been developed. This paper proposes a universal tool to automate the process of component selection by incorporating a tree search. Our technique evaluates the worth of candidate solutions in terms of the customer needs satisfaction and the compatibility between interconnected components. The tree search technique used in this research is not only quick and efficient but also guarantees an optimal solution.
Dynamics of Multibody Systems: Generalized Mass Metric in Riemannian Velocity Space and Recursive Momentum Formulation
Authors: Zhao Qiang , Wu Hong Tao
Published: May 2009

This paper describes two aspects of multibody system (MBS) dynamics on a generalized mass metric in Riemannian velocity space and recursive momentum formulation. Firstly, we present a detailed expression of the Riemannian metric and operator factorization of a generalized mass tensor for the dynamics of general-topology rigid MBS. The derived expression allows a clearly understanding the components of the generalized mass tensor, which also constitute a metric of the Riemannian velocity space. It is being the fact that there does exist a common metric in Lagrange and recursive Newton-Euler dynamic equation, we can determine, from the Riemannian geometric point of view, that there is the equivalent relationship between the two approaches to a given MBS. Next, from the generalized momentum definition in the derivation of the Riemannian velocity metrics, recursive momentum equations of MBS dynamics are developed for progressively more complex systems: serial chains, topological trees, and closed-loop systems. Through the principle of impulse and momentum, a new method is proposed for reorienting and locating the MBS form a given initial orientation and location to desired final ones without needing to solve the motion equations.
Optimization of Complex Engineered Systems Under Risk and Uncertainty
Authors: Choi Seung-Kyum , Fathianathan Mervyn , Schaefer Dirk
Published: May 2009

The advances in information technology significantly impact the engineering design process. The primary objective of this research is to develop a novel probabilistic decision support tool to assist management of structural systems under risk and uncertainty by utilizing a stochastic optimization procedure and IT tools. The proposed mathematical and computational framework will overcome the drawbacks of the traditional methods and will be critically demonstrated through large-scale structural problems. The efficiency of the proposed procedure is achieved by the combination of the Karhunen-Loeve transform with the stochastic analysis of polynomial chaos expansion to common optimization procedures. The proposed technology, comprising new and adapted current capabilities, will provide robust and physically reasonable solutions for practical engineering problems.
A Partitioned Iteration Method Employing CG-Following Reference Frames for Distributed Simulation of Flexible Multibody Systems
Authors: Ryu Geunsoo , Ma Zheng-Dong , Hulbert Gregory M.
Published: May 2009

A distributed simulation platform, denoted as D-Sim, has been developed previously by our research group, which comprises three essential attributes: a general XML description for models suitable for both leaf and integrated models, a gluing algorithm, which only relies on the interface information to integrate subsystem models, and a logical distributed simulation architecture that can be realized using any connection-oriented distributed technology. The overarching research focus is to integrate heterogeneous subsystem models, e.g., multibody dynamics subsystems models and finite element subsystems models and to conduct seamlessly integrated simulation and design tasks in a distributed computing environment. A Partitioned Iteration Method (PIM) is proposed in this paper, which decouples the rigid body motion from elastic deformation of the simulated system using an iteration scheme. The method employs a CG-following reference frame for each deformable body in the distributed simulation of flexible multibody systems. The resultant simulation system can be used to integrate distributed deformable bodies D-Sim, while allowing large rigid body motions among the bodies or subsystems. It also enables using independent simulation servers; where each server can run commercially available or research-based MBD and/or FEM codes. Examples are provided that demonstrate the performance of the method and also how to decouple and integrate rigid body motion and elastic deformation using the developed gluing algorithm.
Comparison of Three-Dimensional Flexible Thin Plate Elements for Multibody Dynamic Analysis: Finite Element Formulation and Absolute Nodal Coordinate Formulation
Authors: Schwab A. L. , Gerstmayr J. , Meijaard J. P.
Published: May 2009

Three formulations for a flexible 3-D thin plate element for dynamic analysis within a multibody dynamics environment are compared: a classical Discrete Kirchhoff Triangle (DKT) with large displacements and large rotations, a fully parametrized rectangular element according to the absolute nodal coordinate formulation (ANCF) and a rectangular element according to the ANCF with an elastic midplane approach. The comparison is made by means of a small deformation static test and extensive eigenfrequency analyses on a stylized problem. It is shown that the DKT element can describe arbitrary rigid body motions and that both the DKT element and the thin plate ANCF element show good convergence to analytic solutions by increasing number of elements, and suppress shear locking which is present in the fully parametrized ANCF element.
Cycle-Based Robot Drive Train Optimization Utilizing SVD Analysis
Authors: Feng Xiaolong , Sander-Tavallaey Shiva , O¨lvander Johan
Published: May 2009

Designing a drive train for an industrial robot is a demanding task where a set of design variables need to be determined so that optimal performance is obtained for a wide range of different duty cycles. The paper presents a method where singular value decomposition (SVD) is used to reduce the design variable set. The application is a six degree of freedom serial manipulator, with nine drive train parameters for each axis and the objective is to minimize the cycle time on 122 representative design cycles without decreasing the expected lifetime of the robot. The optimization is based on a simulation model of the robot and conducted on a reduced set of the initial duty cycles and with the design variables suggested by the SVD analysis. The obtained design reduces the cycle time with 1.6% on the original design cycles without decreasing the life time of the robot.
Adaptive Complex Method for Efficient Design Optimization
Authors: Pettersson Marcus , O¨lvander Johan
Published: May 2009

Box’s Complex method for direct search has shown promise when applied to simulation based optimization. In direct search methods, like Box’s Complex method, the search starts with a set of points, where each point is a solution to the optimization problem. In the Complex method the number of points must be at least one plus the number of variables. However, in order to avoid premature termination and increase the likelihood of finding the global optimum more points are often used at the expense of the required number of evaluations. The idea in this paper is to gradually remove points during the optimization in order to achieve an adaptive Complex method for more efficient design optimization. The proposed method shows encouraging results when compared to the Complex method with fix number of points and a quasi-Newton method.
Path-Constrained Motion Planning for Robotics Based on Kinematic Constraints
Authors: van Dijk N. J. M. , van de Wouw N. , Nijmeijer H. , Pancras W. C. M.
Published: May 2009

Common robotic tracking tasks consist of motions along predefined paths. The design of time-optimal path-constrained trajectories for robotic applications is discussed in this paper. To increase industrial applicability, the proposed method accounts for robot kinematics together with actuator velocity, acceleration and jerk limits instead of accounting for the generally more complex dynamic equations of a manipulator with actuator torque and torque-rate limits. Besides actuator constraints also constraints acting on process level are accounted for. The resulting non-convex optimization problem is solved using a cascade of genetic algorithms and Nelder-Mead’s method. Simulations performed on a Puma 560 manipulator model show that for a proper choice of the kinematic constraints results can be obtained that match the quality of those obtained using the more complex dynamic constraint approach.
TERFENOL-D Based Transducer for Power Harvesting From Vibration
Authors: Berbyuk Viktor
Published: May 2009

The proposed paper addresses the problem of vibration-to-electric energy conversion using giant magnetostrictive material — TERFENOL-D. Both theoretical and experimental results of the study of performance of magnetostrictive transducer which was built at Chalmers University of Technology are presented. The mathematical models have been developed for modeling of magnetostrictive transducer based on constitutive equations of magnetoelastic behavior of TERFENOL-D rod and standard formulae of electromagnetism for induced voltage and current in the pick-up coil due to variation of magnetic field. The developed models are used to evaluate induced voltage and electrical power output for displacement driven and as well as force driven transducers. Several experiments using test rig generating periodic excitations with frequency up to 1000 Hz have been conducted for newly developed physical prototype of transducer having TERFENOL-D rod with 50 mm in length and 15 mm in diameter as active material. The validity of the transducer model is illustrated by comparison simulation data with experiment. The obtained results of the study the vibration-to-electric energy conversion using TERFENOL-D have confirmed the potential of using giant magnetostrictive materials for power harvesting from vibration.
Delayed-Acceleration Feedback for Active-Multimode Vibration Control of Cantilever Beams
Authors: Alhazza Khaled A. , Nayfeh Ali H. , Daqaq Mohammed F.
Published: May 2009

We present a single-input single-output multimode delayed-feedback control methodology to mitigate the free vibrations of a flexible cantilever beam. For the purpose of controller design and stability analysis, we consider a reduced-order model consisting of the first n vibration modes. The temporal variation of these modes is represented by a set of nonlinearly-coupled ordinary-differential equations that capture the evolving dynamics of the beam. Considering a linearized version of these equations, we derive a set of analytical conditions that are solved numerically to assess the stability of the closed-loop system. To verify these conditions, we characterize the stability boundaries using the first two vibration modes and compare them to damping contours obtained by long-time integration of the full nonlinear equations of motion. Simulations show excellent agreement between both approaches. We analyze the effect of the size and location of the piezoelectric patch and the location of the sensor on the stability of the response. We show that the stability boundaries are highly dependent on these parameters. Finally, we implement the controller on a cantilever beam for different controller gain-delay combinations and assess the performance using time histories of the beam response. Numerical simulations clearly demonstrate the controller ability to mitigate vibrations emanating from multiple modes simultaneously.
A Distributed Environment for Collaborative Design
Authors: Chen Zhiqiang , Siddique Zahed
Published: May 2009

Tools and applications are needed to provide engineers with support to design in a distributed and collaborative environment. These systems and tools need to make it possible to share design information, and schedule design process so that a group of distributed engineers can work together. Software level design is the prerequisite condition for applying any design approaches into the distributed mechanical design and in this paper, basic design systems and design tools are developed so that a typical distributed mechanical design can be supported. Requirements for a collaborative design system are presented, along with requirements to develop a prototype distributed system. The system is demonstrated on reverse engineering project for an aircraft component.
The Capacity of Superfinished Vehicle Components to Increase Fuel Economy
Authors: Winkelmann Lane , El Saeed Omer , Bell Matt
Published: May 2009

The lubricant industry is emphasizing the use of low-viscosity lubricants to increase fuel economy. Fuel mileage increases as high as 8% are claimed when conventional engine and driveline lubricants are replaced with new-generation products. Low viscosity lubricants, however, must contain more robust anti-wear and extreme pressure additives to counteract their reduced λ ratio. Consequently, switching to lower viscosity lubricants in order to gain fuel economy entails risk. Should the additive package fail to perform, engine, transmission, and drivetrain components will be seriously damaged. It seems appropriate then, to attempt to increase the λ ratio for low viscosity lubricants. This, of course, can be done by reducing surface roughness. Superfinishing the surface using chemically accelerated vibratory finishing is a practical and well proven approach for accomplishing this. This paper will present data from both laboratory and field testing demonstrating that superfinished components exhibit lower friction, operating temperature, wear and/or higher horsepower, all of which translate directly into increased fuel economy.
Complex Motions in a Periodically Forced Oscillator With Multiple Discontinuities
Authors: Luo Albert C. J. , Patel Mehul T.
Published: May 2009

The complex motions in periodically forced oscillator with multiple discontinuities are investigated in this paper. From the local singularity theory in discontinuous systems, the passability condition of motion flow from one domain to the adjacent one in phase space is presented, and the sliding and grazing conditions of motion flows to discontinuous boundaries are given to understand the mechanism of such complex motions. From the separation boundary, the generic mappings are defined for mapping structures. A generalized mapping structure is introduced for all complex periodic motions, and the local stability and bifurcations of periodic motions in such a discontinuous system are discussed. The passability of motion flow to the discontinuous boundary is used for motion continuity, and the grazing condition of flow to the discontinuous boundary is employed for the vanishing of complex motion. Complex periodic motions with sliding and grazing in such a discontinuous system are predicted analytically and chaotic motions are also illustrated.
Novel Double-Parallelogram Motion Constraining Mechanisms for Vibration Isolation Systems
Authors: Rastegar Jahangir , Khorrami Farshad
Published: May 2009

Vibration isolation devices are used to attach various systems to their base structure to reduce the transmission of vibration from and/or to the base structure. Vibration isolation devices allow relative motion between the isolated system and the base platform. This relative motion is critical to the effective operation of vibration isolation devices and is used to absorb or divert vibration energy using spring and viscous damping or dry friction elements. In general, larger the allowed relative motion, more effective will be the performance of the isolation system. In certain applications, the introduced relative motion by the vibration isolation device introduces unavoidable and unwanted motion of the isolated system and can significantly degrade its performance, particularly in terms of positioning precision, or limit the range of allowable relative motion, thereby reducing the effectiveness of the isolation system. In this paper, a novel method is presented that uses appropriate linkage mechanisms to constrain relative motions that are introduced by the vibration isolation system that are not necessary for the proper operation of the vibration isolation system but their presence would degrade the performance of the entire system. As an example, a novel double-parallelogram based motion constraining mechanism is presented, which is used to constrain rotational (rocking) motion of an isolation system without hindering its relative translational motion used for vibration isolation. The design of a prototype of such a linkage mechanism used to isolate payloads from launch vehicles during the launch and the results of its successful testing are presented. Other applications of the present method are discussed.
A Study on Forging of Spiral Bevel Gear
Authors: Watanabe Masaki , Maki Minoru , Hirokawa Sumio , Kishimoto Yasuhiro
Published: May 2009

This study reports the method of forging of spiral bevel gear. Two ideas for crowning of tooth surface to obtain point contact for forging gears are proposed. By one idea, tooth surface of pinion meshes with the gear tooth surface by conjugate point contact. And the trace of contact points on the gear tooth surface is perpendicular to the lengthwise direction of gear tooth, namely becomes the “square contact” so called in gear technology. The trace can be set arbitrarily on the gear tooth, by setting the pitch point arbitrarily. By another idea, the trace of contact points lies along the tooth trace of the gear tooth. Both ideas proposed in this report, the numerical dataset of teeth surface of pinion and gear are given by the contact lines with the cutter cone. The dataset of teeth surface of pinion and gear are calculated to cut a pair of electrodes of spiral bevel gear. Tooth contacts of proposed gearing are confirmed by the 3D drawing of tooth surfaces. The tooth contact of the master pinion and gear were made and tested by tooth contact testing apparatus. The contact marks coincide well with the theoretical contact pattern estimated by 3D/CAD expression. The good results of running test of the performance of the master gear has been given. The authors completed the forging of spiral bevel gear pairs by two methods proposed in this report.
Finding the Maximal Turning State of an Arbitrary Mesh
Authors: Watkins Matthew , Rahmani Keyvan , D’Souza Roshan
Published: May 2009

This paper presents a new algorithm for computing the maximal turning state of an arbitrary mesh. This is accomplished by intersecting the mesh with a plane at even intervals along the mesh, and computing the farthest point in that plane from an axis of rotation. The algorithm will run in O(|E|*n) time and θ(n) space, where E is the list of the edges on the mesh and n is the number of intervals used. Because of this, a very high degree of accuracy can be obtained with very little computational cost. The developed algorithm has been implemented and tested on some meshed models.
Attitude Control of Air Spring Mounting System Based on Fuzzy Control
Authors: Bu Wenjun , He Lin , Shan Shujun
Published: May 2009

Air spring is a kind of mount with excellent vibration isolation effect and it uses air as its elastic component. But its height is subject to constant change due to air leak or environment temperature and this restricts its engineering application. So some studies on attitude control are carried out, focusing on statically indeterminate and multivariable coupling air spring mounting systems in this paper. The Statically indeterminate problem is transformed through adding the constraint of loading evenness among air springs. After analyzing the model of this controlled object, a new control strategy based on coupling characteristic recognition is presented and combined with fuzzy logic control to realize attitude control of the multivariable coupling system. Finally, a test is conducted to show that the control strategy is feasible and the control system has good static and dynamic properties.
Bayesian Analysis of Adaptive One-Factor-at-a-Time Experimentation
Authors: Wang Hungjen , Frey Daniel D. , Kaufman Gordon M.
Published: May 2009

This paper considers the problem of achieving improvements through adaptive experimentation. To limit the focus we consider only design spaces with discrete two-level factors. We prove that, in a Bayesian framework, one factor at a time experimentation is an optimally efficient response to step by step accrual of sample information. We derive Bayesian predictive distributions for experimentation outcomes given natural conjugate priors. Using an example based on fatigue life of weld repaired castings, we show how to use our results.
Damage Detection of Gearbox Using Wavelet-Based Singularity Analysis Method
Authors: Miao Qiang , Huang Hong-Zhong , Fan Xianfeng
Published: May 2009

Damage detection of machinery is always a research field that attracts attentions of many people. In this paper, a novel technique for gearbox damage detection is investigated, which is a wavelet-based singularity analysis method. Wavelet transform is applied to vibration signal, modulus maxima lines are extracted, and conclusions are made based on these lines. Simulated and real vibration data have been analyzed using this approach. The results are presented to show the effectiveness of the method.
Kinematics of a Pure Translational UPS/3RPaPaR Parallel Mechanism
Authors: Lee Chung-Ching , Lee Po-Chih
Published: May 2009

From the viewpoint of kinematics, a type of 3 degrees of freedom (dofs) UPS/3RPaPaR overconstrained parallel mechanism (Pa means the hinged 4R parallelogram) with pure translational motion is presented for the development of automatic assembly devices or as a regional structure in the hybrid parallel platform. In the beginning, the formation & mobility are elucidated and the 4×4 transformation matrix & the D-H notation with specific geometric constraints verify the pure translational motion. The forward and inverse kinematic analyses are then established in the analytical closed-form through the matrix method. Besides, we take a numerical illustration for the confirmation of correctness of the derived equations. The determination of workspace is also attained by the intersection of volumes swept by each limb. In addition, the Jacobian matrix and its condition number indicated by Euclidean norm as a function of design parameters are further achieved. Finally, the singularity analysis of the configuration based on the direct and inverse kinematic J-matrix during the movement is identified in detail.
A Design Process Model and a Computer Tool for Service Design
Authors: Shimomura Yoshiki , Sakao Tomohiko , Sundin Erik , Lindahl Mattias
Published: May 2009

Manufacturers at present face new circumstances in terms of consumer services and serious environmental problems. An effective way to deal with these circumstances may be to pursue qualitative satisfaction rather than quantitative sufficiency. The aim of this paper is to demonstrate the effectiveness of Service Engineering, including the service design process model, to increase customer satisfaction. The redesign of services offered by a global warehouse manufacturer is used as an example of the application. Four redesign options, such as rapid delivery of components and a robust electrical system, were generated. The effectiveness of the method was demonstrated by the application.
A Novel Capacitive Detection Scheme With Inherent Self-Calibration
Authors: Trusov Alexander A. , Shkel Andrei M.
Published: May 2009

This paper reports a novel capacitive detection method which is robust to variations of such critical parameters as the nominal capacitance, frequency and amplitude of the probing voltage, and gain of the trans-impedance amplifier. The approach constructively utilizes inherent nonlinearity of parallel plate sense capacitors in order to measure amplitude of sinusoidal motion. In the case of parallel plate detection signal, multiple harmonics exist and carry redundant information about the amplitude of mechanical motion. The amplitude of motion can be extracted from the ratio of two simultaneously measured harmonics. The paper presents details of a real-time measurement algorithm. Functionality of the algorithm is confirmed by simulations and experiments. The technique is especially valuable for capacitive detection and self-calibration in resonant structures, such as gyroscopes, resonant microbalances, and chemical sensors.
Experimentally-Tuned Mathematical Model for Drillstring Vibrations
Authors: Khulief Y. A. , Al-Sulaiman F. A.
Published: May 2009

Field experience manifests that drillstring vibration is one of the major causes for a deteriorated drilling performance. It is crucial to understand the complex vibrational mechanisms experienced by a drilling system in order to better control its functional operation and improve its performance. Experimental studies of drillstring dynamics are essential to complement the theoretical studies, and to alleviate the complexity of such dynamic models. This paper presents an experimental investigation using a specially designed drilling test rig. The test rig can simulate the drillstring vibrational response due to various excitation mechanisms, which include stick-slip, well-borehole contact, and drilling fluid interaction. The test rig is driven by a variable speed motor which allows for testing different drilling speeds, while a magnetic tension brake is used to simulated stick-slip. In addition, a shaker is employed to excite the drillstring axially in order to simulate the weight-on-bit (WOB). The drillstring is instrumented for vibration measurements. The experimentally identified parameters are used to refine the finite element multibody model of the drillstring, which was derived earlier by the investigators [1]. Comparisons with published data demonstrate the reliability of the developed scheme for prediction of drillstring vibrations.
Approximate Constitutive Relation for Lap Joints Using a Tribo-Mechanical Approach
Authors: Farhang K. , Segalman D. , Starr M.
Published: May 2009

Energy dissipation in mechanical joints occurs as a result of micro-slip motion between contacting rough surfaces. An account of this phenomenon is especially challenging due to the vast differences in the length and time scale differences between the macro-mechanical structure and the micron-scale events at the joint interface. This paper considers the contact between two nominally flat surfaces containing micron-scale roughness. The rough surface interaction is viewed as a multi-sphere elastic interaction subject to a periodic tangential force. It combines the Mindlin’s formulation [1, 2] for the elastic interaction of two spheres with the Greenwood and Williamson’s [3] statistical approach for the contact of two nominally flat rough surfaces so as to develop a model for multi-sphere problem in which sphere radii, contact load and the number of spheres in contact can only be known in a statistical sense and not deterministically.
Robust Design Concept in Possibility Theory and Optimization for System With Both Random and Fuzzy Input Variables
Authors: Du Liu , Choi Kyung K. , Lee Ikjin
Published: May 2009

Whereas the robust design concept has been well established in the probability theory, it has not been developed in the possibility theory. For problems where accurate statistical information for input data is not available, a possibility-based (or fuzzy set) robust design concept is proposed in this paper by investigating the similarity between the membership function of the fuzzy variable and the cumulative distribution function of the random variable. Based on the probability-possibility consistency principle, a random variable that corresponds to the fuzzy variable is introduced in this paper in order to define the robust design concept for the fuzzy variable. For the system with input fuzzy variables, the robustness measure of the output performance is computed using the performance measure integration (PMI) method, while the integration points are obtained from the inverse possibility analysis by using the maximal possibility search method with interpolation (MPS). For the system with mixed random and fuzzy input variables, the robustness measure of the output performance is computed using PMI method, with the integration points obtained from the inverse mixed analysis by using the maximal failure search method (MFS). A new mixed (random and fuzzy) variable robust design optimization (MVRDO) method is proposed and several numerical examples are used to verify the robust design concept in the possibility theory and the MVRDO formulation.
Gear Wearing Faults Diagnosis Using Order Tracking
Authors: Li He , Zhang Yimin , Wen Bangchun , Wen Feng
Published: May 2009

Machine vibration signal has been used in fault detection and diagnosis. Modulation and non-stationary existing in the signal generated by a faulty gearbox presents challenges to effective fault detection. In order to study the phenomenon of gear wearing, the vibration of a gearbox in a transmission shaft is measured by the order tracking method. Order tracking has the ability to detect the fault issue of gear wearing. Measured results indicate characteristic parameters of gear wearing. And compared with the tradition spectral analysis, the advantages of order tracking were presented in the paper. These measured data and analyzed results were the important guidance in the dynamic design, modification and operation management of transmission box.