bluuebunny/crossref_metadata_2025 huggingface dataset:
Optimal Hybridization of Battery, Engine and Motor for PHEV20
Authors: Shahi Shashi K. , Wang G. Gary , An Liqiang , Bibeau Eric
Published: June 2012

A plug-in hybrid electric vehicle (PHEV) relies on relatively larger storage batteries than conventional hybrid electric vehicles. The characteristics of PHEV batteries, as well as hybridization of the PHEV battery with the engine and electric motor, play an important role in the design and potential adoption of PHEVs. To exhaustively evaluate all the possible combinations of available types of batteries, motors and engines, the total computational time is prohibitive. This work proposed an integrated optimal design strategy to address this problem. The recently developed Pareto set pursuing (PSP) multi-objective optimization approach is employed to perform optimal hybridization. Each PHEV with chosen battery, motor and engine is designed for optimal component sizing using the Powertrain System Analysis Toolkit (PSAT) software. The methodology is demonstrated with the Toyota Prius PHEV20: PHEV version sized for 20 miles (32.1 km) of all electric range (AER). Fuel economy, operating cost, and green house gases emissions are simultaneously optimized from 4,480 possible combinations of design parameters: 20 batteries, 14 motors, and 16 engines. The hybridization optimization is performed on two different drive cycles—Urban dynamometer driving schedule (UDDS) and Winnipeg weekday duty cycle (WWDC). It was found that battery, motor, and engine work collectively to define an optimal hybridization scheme and the optimal hybridization scheme varies with each driving cycle. The proposed method and software platform could be applied to optimize other powertrain designs.
Kinematic Modeling and Internal Motion Analysis of Proteins From a Robot Kinematics Viewpoint
Authors: Arikawa Keisuke
Published: June 2012

This paper discusses the kinematic modeling of proteins and the analysis of their internal motion from the viewpoint of robot kinematics. First, a kinematic model of a protein is introduced. This model consists of multiple serial link mechanisms and interaction lines (lines between alpha carbons). The protein model is regarded as a type of a robot manipulator that uses joint angles to control the lengths of the interaction lines, and the Jacobian matrix of the manipulator is derived. On the basis of this Jacobian matrix, the basic equations for calculating the deformation caused by external forces and evaluating the structural compliance of specified parts are derived. Finally, by combining the derived basic equations, we analyze the internal motions of lactoferrin and hemoglobin and compare the results with the reported measured characteristics of their internal motions. Despite the approximations by the model, the results obtained by the proposed method agree with the measured internal motion.
A Function Based Approach to TRIZ
Authors: Nix Anthony A. , Sherrett Ben , Stone Robert B.
Published: June 2012

Function based design methods — those that are largely a derivative of Pahl and Beitz’s systematic approach — are a powerful tool employed in a variety of engineering design contexts. However, many other design methodologies exist and are useful in solving design problems. These methods include varying approaches from Suh’s Axiomatic Design to Altshuller’s Theory of Inventive Problem Solving (TIPS or TRIZ) to the business-motivated Ulwick’s Outcome Driven Method. In this paper an attempt to merge the philosophy of functional design with the problem solving approach of TRIZ is undertaken. A framework is proposed combining functional modeling formalized by the Functional Basis with TRIZ. The process of merging the two methodologies is presented along with the key contribution, a matrix that relates the vocabulary of the Functional Basis with the 40 inventive principles of TRIZ. The use of the Functional Basis-TRIZ (FB-TRIZ) hybrid design methodology is described and a case study is presented demonstrating its use as well as the creative solutions that the approach affords.
Boundary Element Parallel Computation for 3D Elastostatics Using CUDA
Authors: Wang Yingjun , Wang Qifu , Wang Gang , Huang Yunbao , Wei Yixiong
Published: June 2012

Finite Element Method (FEM) is pervasively used in most of 3D elastostatic numerical simulations, in which Computer Aided Design (CAD) models need to be converted into mesh models first and then enriched with semantic data (e.g. material parameters, boundary conditions). The interaction between CAD models and FEM models stated above is very intensive. Boundary Element Method (BEM) has been used gradually instead of FEM in recent years because of its advantage in meshing. BEM can reduce the dimensionality of the problem by one so that the complexity in mesh generation can be decreased greatly. In this paper, we present a Boundary Element parallel computation method for 3D elastostatics. The parallel computation runs on Graphics Processing Unit (GPU) using Computing Unified Device Architecture (CUDA). Three major components are included in such method: (1) BEM theory in 3D elastostatics and the boundary element coefficient integral methods, (2) the parallel BEM algorithm using CUDA, and (3) comparison the parallel BEM using CUDA with conventional BEM and FEM respectively by examples. The dimension reduction characteristics of BEM can dispose the 3D elastostatic problem by 2D meshes, therefore we develop a new faceting function to make the ACIS facet meshes suitable for Boundary Element Analysis (BEA). The examples show that the GPU parallel algorithm in this paper can accelerate BEM computation about 40 times.
A Comprehensive Modeling of Piezoresistive Microcantilever Sensors Used in Piezoactive Materials Characterization
Authors: Faegh Samira , Jalili Nader
Published: June 2012

Micro-Cantilever Sensors (MCS) have caught a widespread attention during past couple of years for offering label free biodetection. Amongst many current MCS-based measurement platforms, piezoresistive MCS offer a great advantage over other types of MCS especially when compared with optical measurements where sample preparation and laser alignment and adjustment are serious limitations. In order to address the uncertainties and nonlinearities inherent in nanoscale, a comprehensive modeling of the system is required. In almost all of the studies targeting piezoresistive MCS, the system is modeled as a simple lumped-parameters system which does not describe all phenomena and dynamics of the system. In the first part of this study, a comprehensive distributed-parameters modeling is proposed for the piezoresistive MCS. A new method of excitation is developed and modeled through cantilever tip instead of the commonly used techniques such as base excitation or excitation through piezo-layers deposited over cantilever surface. In the second part of this study, a comprehensive distributed-parameters modeling is proposed for the piezoresistive MCS-based force microscopy in contact with a piezoelectric sample. The output voltage of the piezoresistive layer is determined and utilized as a function of cantilever deflection through a piezoresistive modeling framework. Extensive numerical simulations are performed to demonstrate the effectiveness of the modeling framework presented here.
Establishing and Maintaining Wireless Communication Coverage Among Multiple Mobile Robots via Fuzzy Control
Authors: Zhong Xu , Zhou Yu
Published: June 2012

This paper addresses the critical issue of establishing and maintaining desired wireless communication connectivity in a team of collaborative mobile robots, which is highly demanded for reliable functioning of multi-robot systems but challenging in realistic environments. The signal propagation of wireless communications among mobile robots is affected by not only the transmission power and distance but also obstacles and other environmental conditions as well as robot movement, which result in signal loss, attenuation, multi-path fading and shadowing. Consequently, the communication condition among mobile robots in a physical environment is usually unstable, and it is difficult to accurately predict the actual communication ranges of robots. We propose a decentralized control strategy which, based on perceived link quality, adopts fuzzy control to accommodate the fluctuating communication condition, and approach and maintain desired and reliable communication connections among neighboring robots. The effectiveness of the proposed scheme has been verified in several simulated environments with different signal propagation conditions based on a probabilistic signal propagation model.
Characterizing Modularity, Hierarchy and Module Interfacing in Complex Design Systems
Authors: Sarkar Somwrita , Dong Andy
Published: June 2012

Modular engineering systems have multiple benefits over their more integral counterparts. Despite the importance of modularity, metrics and methods for a precise quantitative characterization of modularity, hierarchy and module interfacing remain relatively ambiguous. In this paper, using graph theory and linear algebra, we develop a spectral approach to establish: (1) a metric to characterize modularity, hierarchy and module interfacing in complex engineering systems; and, (2) a method for module identification and system decomposition that addresses hierarchical and overlapping organization of modularity in a complex system. The Singular Values (SV) signatures of random, regular, modular and hierarchically modular benchmark graph models are used to establish the metric. Then, the method is applied to a real design model and its modularity signature is assessed. The modularity signature of a real world system is shown to sit in the continuum established by the extremes of random, regular and modular and hierarchically modular graph models. The main contribution of the work is that it proposes that modularity is an aggregate concept that is measured in terms of multiple concepts expressed as graph properties. An ideal numeric modularity measurement index would have to incorporate these multiple criteria that affect modularity. The method can be used in the conceptual and detailed design stages for purposes of redesigning a product based on the degree of desired modularity.
Stability of a Pivoting Fluid-Filled Container
Authors: Sah Si Mohamed , Mann Brian P.
Published: June 2012

This paper investigates the stability of a pivoting cylindrical container that is slowly filled with fluid. The stability of the upright and tilt angle equilibria is studied by using the Lagrange-Dirichlet theorem. The potential energy of the system is given for two regions that are delimited by an edge angle, and two spill angles. A bifurcation diagram is obtained showing the stability of the upright and tilt angle equilibria as function of both the fluid height in the container and the pivot location. In particular, it is shown that the upright angle equilibrium undergoes a pitchfork bifurcation and it is also found that two stable equilibria may coexist for some fluid heights and pivot point location.
Analytical Compliance Analysis and Synthesis of Flexure Mechanisms
Authors: Su Hai-Jun , Shi Hongliang , Yu JingJun
Published: June 2012

This paper presents a symbolic formulation for analytical compliance analysis and synthesis of flexure mechanisms with arbitrary topologies. Compliance analysis or mapping is to determine the relationship between the deformation of a mechanism and the external loading applied. It is a crucial step for the control and design of flexure mechanisms. Most of the current work relies on physical experiments or numerical simulations for studying the compliance or stiffness of flexure mechanisms. There is a lack of formal tools for the compliance synthesis whose goal is to determine the geometry of flexures or assembly of multiple flexures for a prescribed compliance in the motion direction of interest. In this work, we first derive a symbolic formulation of the compliance and stiffness matrices for commonly-used flexure elements, flexure joints and simple chains. Elements of these matrices are all explicit functions of flexure parameters. To analyze a complex flexure mechanism, we subdivide the mechanism into multiple structural modules which we identify as serial, parallel or hybrid chains. We then analyze each module with the known flexure structures in the library. At last we use a bottom-up approach to obtain the compliance matrix for the overall mechanism. Our symbolic formulation enables subsequent compliance synthesis or sensitivity analysis which is to determine how each flexure parameter affects the overall compliance of the mechanism. Four practical examples are provided to demonstrate the approach. The result is a robust design method for the compliance analysis and synthesis of flexure mechanisms.
Active Variable Wheelbase as an Innovative Approach in Vehicle Dynamic Control
Authors: Goodarzi Avesta , Soltani Amir , Esmailzadeh Ebrahim
Published: June 2012

Active variable wheelbase (AVW) has been introduced here as an innovative vehicle dynamic control method in which, the position of the front or rear axle relative to the vehicle C.G. can be actively varied. An attempt has been made to show the potential capabilities of this method in improving the road handling and stability of vehicles regardless of its embedded technical difficulties. For this purpose the proposed method has been conceptually studied in the first step and has been shown that one can generate the stabilizing yaw moment by changing the distance of the vehicle C.G. from the front or rear axles. Then the proposed concept has been theoretically studied using a simple vehicle dynamic model incorporated with the Magic Formula tire model. A comprehensive nonlinear 8 DOF vehicle model and a ‘model following control strategy’ have been used to evaluate the performance of AVW systems. The vehicle dynamic behavior when it is either uncontrolled or equipped with an AVW system has been simulated. Simulation results show that AVW can be considered as an innovative method for vehicle dynamic control in future.
Robust Disturbance Observer-Based Adaptive Fuzzy Controller for Pneumatic Muscle Actuators
Authors: Jamwal Prashant K. , Xie Sheng Quan , Quigley Sean
Published: June 2012

Variants of Fuzzy logic controllers (FLC) have been widely used to control the systems characterized by uncertain and ambiguous parameters. Control objectives for such systems become more challenging when they are subjected to uncertain environments. Human-robot interaction is such phenomenon wherein robot control difficulties are further augmented due to human intervention. State of the art of research in FLC has been limited in establishing a trade-off between accuracy and interpretability, since achieving both these performance measures simultaneously is difficult. In the present research, an adaptive FLC has been designed in order to achieve better accuracy and higher interpretability. Supported by another instance of FLC as disturbance observer, the proposed controller has adaptive mechanism specifically designed to alter its parameters. The adaptive FLC has been implemented to control actuation of a pneumatic muscle actuator (PMA). Experimental results show excellent trajectory tracking performance of the PMA in the presence of varying environment.
Modeling and Vibration Control of a Flexible Rotor by Using Magnetic Bearings
Authors: Nomoto Takuya , Hunakoshi Daisuke , Watanabe Toru , Seto Kazuto
Published: June 2012

This paper presents a new modeling method and a control system design procedure for a flexible rotor with many elastic modes using active magnetic bearings. The purpose of our research is to let the rotor rotate passing over the 1st and the 2nd critical speeds caused by flexible modes. To achieve this, it is necessary to control motion and vibration of the flexible rotor simultaneously. The new modeling method named as Extended Reduced Order Physical Model is presented to express its motion and vibration uniformly. By using transfer function of flexible rotor-Active Magnetic Bearings system, we designed a Local Jerk Feedback Control system and conducted stability discrimination with root locus. In order to evaluate this modeling and control method, levitation experimentation is conducted.
Profile Optimization of Table Top Speed Hump for Speed Control
Authors: Botha Theunis R. , Els Pieter S. , Uys Petronella E. , Bester Rudolf
Published: June 2012

Speed bumps are the most commonly used measure to control speeding in urban areas world wide. Specifications on profiles and dimensions are largely based on road tests. Studies into speed bumps, directed at evaluating their effectiveness in reducing accidents and their environmental impact, have brought some negative aspects concerning speed bumps to light. These aspects include incidents of spinal and neck injury or loss of control while speeding over speed bumps. Observations have also shown that speeding over certain speed bumps often result in an improvement in ride comfort, thus negating the effectiveness of speed bumps as a measure to control speeding. This paper addresses these aspects by considering the optimization of a speed bump’s profile. The profile is optimized by means of a validated non-linear four degree of freedom vehicle model, as well as the gradient based LFOPC optimization algorithm. The optimized profile allows for increased ride comfort at speeds at and below the designed speed. The ride comfort decreases with an increase in vehicle speed while the vehicle response remains within boundaries set up to reduce the possibility of injury or loss of vehicle control.
Bag-of-Features Sampling Techniques for 3D CAD Model Retrieval
Authors: Wang Y. , Lu W. F. , Fuh J. Y. H. , Wong Y. S.
Published: June 2012

This paper investigates two sampling strategies, dense sampling and PHOW sampling, for bag-of-features 3D CAD model retrieval. Previous methods [1] use original salient SIFT feature detection for general 3D model retrieval which does not suit the need for CAD models representation. CAD models contain mostly piecewise-smooth surfaces and thus only sharp edges can be described. To overcome these limitations, two new sampling strategies are investigated to improve the feature extraction process. Dense sampling extracts SIFT features on regular spatial grids with even spacing. Pyramid Histogram Of visual Words (PHOW) [2] extracts features on repeatedly finer scales. Both the two sampling methods extract features that are covered the whole shape. In addition, the influences of codebook size and distance metric are also studied to optimize the retrieval performance. Experiments on Purdue Engineering Benchmark [3] show that the proposed sampling techniques achieve better retrieval accuracy than the original salient SIFT sampling method.
Modeling and Control of Active Vibration Isolation System Taking the Dynamics of Elastic Load Into Account by Using the Reduced Order Physical Model
Authors: Sudo Keisuke , Watanabe Toru , Seto Kazuto
Published: June 2012

This paper deals with the control system design for active isolation table[1][2][3]. It aims at controlling vibration of the installed object and isolation table. An experimental isolation table with flexible loaded object is built. Control simulations are carried out by using feedback controller designed according to LQ optimal control theory.
Gear Whine Noise Spectra Caused by Transmission Errors
Authors: Fuentes Alfonso , Gonzalez-Perez Ignacio , Nagamoto Hiroyuki , Hayasaka Kenichi
Published: June 2012

The modern theory of gearing is based on the design of gear drives according to the size and location of the contact pattern as well as the maximum level and type of the obtained function of transmission errors. These factors may reduce the life and the endurance of the gear drive for power transmission or even cause its failure. However, there is a factor that affects the quality perception of the performance of the gear drive and deserves to be taken into account in the design stage of the gear drive. It is called gear whine noise and it depends, among other factors, on the type and maximum level of the function of transmission errors. In this paper, an approach for the determination of the amplitude spectrum of different types and levels of functions of transmission errors is proposed in order to predict one of the sources of the radiated gear whine noise. The evaluation of the amplitude spectrum of the function of transmission errors will be made in terms of Fourier series, using the discrete Fourier transform. Therefore, the influence of the type and level of the function of transmission errors on the amplitude spectrum of their Fourier transforms will be investigated in order to find the suitable type of the function of transmission errors for reduction of the radiated gear whine noise and therefore for designing quiet gears.
Estimation Method of Mesh Excitation Waveform of a Gear System (Hybrid Estimation With Vibration Measurement and Simulation)
Authors: Matsumura Shigeki , Nagumo Toshiya , Houjoh Haruo
Published: June 2012

We propose estimation method of frequency response function and mesh excitation waveform combining vibration measurement and simulation. It can be used to estimate tooth surface contacting condition on running gear unit. It may become possible to verify gear vibration simulation. For the verification of proposed method, vibration measurements are done both on the driven gear and on the gearbox simultaneously. Though frequency response functions are different between these two measurement results, estimated excitation wave form become almost the same as expected.
Two Lie Group Formulations for Dynamic Multibody Systems With Large Rotations
Authors: Bru¨ls Olivier , Arnold Martin , Cardona Alberto
Published: June 2012

This paper studies the formulation of the dynamics of multibody systems with large rotation variables and kinematic constraints as differential-algebraic equations on a matrix Lie group. Those equations can then be solved using a Lie group time integration method proposed in a previous work. The general structure of the equations of motion are derived from Hamilton principle in a general and unifying framework. Then, in the case of rigid body dynamics, two particular formulations are developed and compared from the viewpoint of the structure of the equations of motion, of the accuracy of the numerical solution obtained by time integration, and of the computational cost of the iteration matrix involved in the Newton iterations at each time step. In the first formulation, the equations of motion are described on a Lie group defined as the Cartesian product of the group of translations R3 (the Euclidean space) and the group of rotations SO(3) (the special group of 3 by 3 proper orthogonal transformations). In the second formulation, the equations of motion are described on the group of Euclidean transformations SE(3) (the group of 4 by 4 homogeneous transformations). Both formulations lead to a second-order accurate numerical solution. For an academic example, we show that the formulation on SE(3) offers the advantage of an almost constant iteration matrix.
Multi-Fault Diagnosis of Ball Bearings Using Appropriate IMFs for Envelope Analysis
Authors: Tsao Wen-Chang , Pan Min-Chun
Published: June 2012

The traditional envelope analysis is the presence of an effective method for the rolling bearing fault detection. However, all of the resonant frequency bands must be examined on the process of bearing fault detection. To ameliorate the deficiency, this paper presents a novel concept based on the empirical mode decomposition (EMD) and the envelope analysis to choose an appropriate the resonant frequency bands. By virtue of the band-pass property of EMD, the resonant frequency bands will be allocated in the intrinsic mode function (IMF). Moreover, the rolling elements of bearing strike a local fault on the dual faults and the triple faults will be used to validate the capabilities of the proposed method and comparison studies with the traditional envelope analysis will be discussed. The experimental results show that the proposed method can efficiently and correctly diagnose the bearing multi-fault types.
Grammatical and Semantic Disambiguation of Requirements at Elicitation and Representation Stages
Authors: Christophe Franc¸ois , Wang Min , Coatane´a Eric , Zeng Yong , Bernard Alain
Published: June 2012

The final outcome of a design process depends a lot on the initial conditions of this process. The initial design conditions can be viewed as the initial definition and representation of the design problem in the form of requirement model. Describing the requirements involves considering their elicitation and its transformation in a form that can be further used by engineering designers. These two phases of requirements, elicitation and representation, involve by nature linguistic description. Users, stakeholders or designers express themselves through natural language. Semantics considerations involve understanding aspects that comes down to word selection or connotation but also interpretation aspects of written terms used by communities or persons within particular circumstances and contexts. The present research work is constructed around a central hypothesis: Final design outcomes are strongly dependent on the initial design conditions because of the recursive nature of the design activity. The present article claims that computer tools can support the disambiguation process associated with elicitation and representation. For this reason the authors have developed an experimental process aiming at reducing ambiguity of the parts of the initial conditions of the design process that are expressed in natural language. This disambiguation is considering several levels: the grammar, words selection and context description.
Aerodynamic Design Exploration for Reusable Launch Vehicle Using Multi-Objective Genetic Programming
Authors: Tatsukawa Tomoaki , Nonomura Taku , Oyama Akira , Fujii Kozo
Published: June 2012

A new type of multi-objective genetic programming (MOGP) for design exploration is proposed. The feature of the new MOGP is the simultaneous symbolic regression to multiple variables using correlation coefficients. This methodology is applied to Pareto-optimal solutions of the multi-objective aerodynamic design optimization problem of a bi-conical shape reusable launch vehicle. The MOGP presents symbolic equations which have high correlations to zero-lift drag at supersonic condition, maximum lift-to-drag at supersonic condition and volume of shape through single MOGP run. These equations also have high correlation to another parameter of the body geometry. These results indicate that MOGP is capable of finding composite more efficient design parameters from original design parameters.
An Improved Branch-and-Bound Algorithm for Minimizing the Potential Energy of a Cable-Suspended Rigid Body
Authors: Guay Franc¸ois , Collard Jean-Franc¸ois , Cardou Philippe , Gouttefarde Marc
Published: June 2012

We compute the lowest stable-equilibrium pose of a rigid body suspended in space by an arbitrary number of cables, being given the cable lengths and the attachment-point positions on the fixed frame and on the rigid body. This fundamental problem of mechanics if of interest in the fields of underconstrained cable-driven parallel robots and cooperative towing. The approach of the present work is very similar to one that is reported in a previous paper by the authors. Indeed, the problem is formulated as a potential energy minimization, and is solved using a branch-and-bound algorithm. Hence, we report mainly on improvements in the branching and bounding parts of the algorithm. In short, the idea is to search for the optimum rigid-body pose by partitioning only the rotation subgroup of rigid-body displacements. This is done here by dividing the four-dimensional space of Euler-Rodrigues parameters with polyhedral cones instead of boxes, the latter being normally used for this type of problem. The advantage is that cones conform better to the four-dimensional unit-sphere of Euler-Rodrigues parameters. The convex relaxations of the original optimization problem are then adapted to the newly defined conical subsets. Besides resulting in a more elegant algorithm, this new conical branch-and-bound method leads to a higher efficiency in the case of reported examples.
Multiphysics Modeling of a Tilting Pad Thrust Bearing: Comparison Between White Metal and Polymeric Layered Pads
Authors: Ricci R. , Chatterton S. , Pennacchi P. , Vania A.
Published: June 2012

Oil-film tilting pad thrust bearings are mainly used in supporting the high axial load of the turbine shaft in vertical hydroelectric units or smaller axial loads of turbo machines. The trend for these applications is to replace the white metal with a polymeric material layer such as PTFE or PEEK, improving the bearing performances and extending its operating conditions. This leads to a reduction of the bearing overall dimensions as a consequence of the load capacity increase. Apart the friction and the resistance to chemical attacks properties of the polymeric layer, the main cause on the improved performances of the bearing is the compliance of the pad layer. In particular the polymeric layer reduces the typical pad crowning allowing a more uniform pressure distribution over the pad and a reduction of its maximum value with respect to Babbitt metal pads. Therefore, the design of layered pad requires a deeper investigation such as thermoelastohydrodynamic (TEHD) analyses, including oilthermal effects and bearing thermal deformation. In the paper, the performance of Babbitt metal and polymeric layered pads of standard size offset-pivoted tilting pad thrust bearings of vertical axis units are compared using a multiphysics software able to manage simultaneously the mechanical, the thermal and the fluid problems. Layer and pad deformation, temperature and pressure distributions, and oil-film thickness have been analysed for different operating conditions. The model has been validated using experimental data available in literature.
Service Design Methodology for Cooperative Services
Authors: Watanabe Kentaro , Mikoshiba Satoshi , Tateyama Takeshi , Shimomura Yoshiki , Kimita Koji
Published: June 2012

In accordance with the maturation of industry, the major mean of value offering shifts from mass products to services. To develop successful services, the cooperation with different organizations and individuals is effective since innovative services often require various capabilities and resources which are difficult to obtain by one company. For the realization of such a cooperative service, a design methodology which can handle requirements of various stakeholders and a complex service structure is required. However, the general methodology for cooperative services has not been established. In this paper, the authors propose a service design methodology of cooperative services. This methodology includes a service evaluation framework to adjust the specification of a service which influences the multiple stakeholders, a computational simulation method for service evaluation and a service design process based on the proposed methods.
A Platform Selection Approach Based on Product Family Ontology Modeling
Authors: Johnson Lim Soon Chong , Liu Ying , Lee Wing Bun
Published: June 2012

Product family design is probably the most widely adopted strategy for product realization in mass customization paradigm. With the ever-increasing product offerings in consumer market, current product representation schemes are restricted by their limited capability in handling multiple conceptual relationships amongst product components and rich semantic annotations associated with different design concepts. Previously, we have studied and proposed an ontology-based information representation scheme for product family design, which offers a promising solution to address the aforementioned challenges. In this study, we suggest a new commonality metric and a faceted platform selection approach, which are both created for ontology-based product family representation models. Utilizing this metric and faceted search, we discuss the advantages of our approach compared to existing modeling possibilities. We also exemplify the applications of our proposal towards an optimal configuration of product variants using a case study of four laptop computer families. Finally, we conclude this paper with some indications for future work.
Supporting Co-Design of Physical and Control Architectures of Mechatronic Systems
Authors: Alvarez Cabrera Andre´s A. , Komoto Hitoshi , Tomiyama Tetsuo
Published: June 2012

There is a rather recent tendency to define the physical structure and the control structure of a system concurrently when designing the architecture of a product, i.e., to perform codesign. We argue that co-design can only be enabled when the mutual influence between physical system and control is made evident to the designer at an early stage. Though the idea of design integration is not new, to the best of our knowledge, there is no computer tooling that explicitly supports this activity by enabling co-design as stated before. In this paper the authors propose a method for co-design of physical and control architectures as a better approach to design mechatronic systems, allowing to exploit the synergy between software and hardware and detecting certain design problems at an early stage of design. The proposed approach is supported by a set of tools and demonstrated through an example case.
Identification of the Cutting Forces Coefficients via Milling Process Simulation
Authors: Voronov Sergey A. , Kiselev Igor A. , Yakovlev Maxim G.
Published: June 2012

The paper is devoted to the description of a new technique (numerical and experimental) identification of the dependences between cutting forces and instantaneous chip thickness. It is required to measure only the cutting forces versus cutting conditions. Experimentally, for the given pair the processed material – the tool, coefficients of the cutting forces model are calculated by means of the optimization method (Nelder-Mead algorithm). The mathematical model of the milling process developed by authors on each step of the Nelder-Mead method is used for the process numerical simulation under given coefficients of the cutting force model. The elaborated numerical modeling algorithm allows investigating the dynamics and the kinematics of the milling process. The dynamic model of the tool, the algorithm of geometrical modeling of the instantaneous chip thickness, the finite element model of the detail are embedded into the whole model of the milling process.
Inclination Parameter Estimation for Manipulator and Humanoid Robot Links
Authors: Vikas Vishesh , Crane Carl D.
Published: June 2012

A novel approach of dynamic, non-contact measurement of inclination parameters for robotics applications using the Vestibular Dynamic Inclinometer (VDI) is proposed in the paper. The gravity-invariant Vestibular Dynamic Inclinometer (VDI) is a sensor that consists of symmetrically placed two dual-axis linear accelerometers and one single-axis gyroscope. The deployment of the non-contact sensor is strategic and need not be exactly at the joints. The sensor is also able to estimate the inclination parameters of the base link and the acceleration of the surface of contact. The inclination parameters — base angle, joint angles, angular velocity and angular acceleration, are independent of integration errors/drift.
A Rational Design Approach to Gaussian Process Modeling for Variable Fidelity Models
Authors: Moore Roxanne A. , Romero David A. , Paredis Christiaan J. J.
Published: June 2012

Computer models and simulations are essential system design tools that allow for improved decision making and cost reductions during all phases of the design process. However, the most accurate models tend to be computationally expensive and can therefore only be used sporadically. Consequently, designers are often forced to choose between exploring many design alternatives with less accurate, inexpensive models and evaluating fewer alternatives with the most accurate models. To achieve both broad exploration of the design space and accurate determination of the best alternatives, surrogate modeling and variable accuracy modeling are gaining in popularity. A surrogate model is a mathematically tractable approximation of a more expensive model based on a limited sampling of that model. Variable accuracy modeling involves a collection of different models of the same system with different accuracies and computational costs. We hypothesize that designers can determine the best solutions more efficiently using surrogate and variable accuracy models. This hypothesis is based on the observation that very poor solutions can be eliminated inexpensively by using only less accurate models. The most accurate models are then reserved for discerning the best solution from the set of good solutions. In this paper, a new approach for global optimization is introduced, which uses variable accuracy models in conjuction with a kriging surrogate model and a sequential sampling strategy based on a Value of Information (VOI) metric. There are two main contributions. The first is a novel surrogate modeling method that accommodates data from any number of different models of varying accuracy and cost. The proposed surrogate model is Gaussian process-based, much like classic kriging modeling approaches. However, in this new approach, the error between the model output and the unknown truth (the real world process) is explicitly accounted for. When variable accuracy data is used, the resulting response surface does not interpolate the data points but provides an approximate fit giving the most weight to the most accurate data. The second contribution is a new method for sequential sampling. Information from the current surrogate model is combined with the underlying variable accuracy models’ cost and accuracy to determine where best to sample next using the VOI metric. This metric is used to mathematically determine where next to sample and with which model. In this manner, the cost of further analysis is explicitly taken into account during the optimization process.
Motion Planning of Uncertain Fully-Actuated Dynamical Systems: An Inverse Dynamics Formulation
Authors: Hays Joe , Sandu Adrian , Sandu Corina , Hong Dennis
Published: June 2012

This work presents a novel nonlinear programming based motion planning framework that treats uncertain fully-actuated dynamical systems described by ordinary differential equations. Uncertainty in multibody dynamical systems comes from various sources, such as: system parameters, initial conditions, sensor and actuator noise, and external forcing. Treatment of uncertainty in design is of paramount practical importance because all real-life systems are affected by it; ignoring uncertainty during design may lead to poor robustness and suboptimal performance. System uncertainties are modeled using Generalized Polynomial Chaos and are solved quantitatively using a least-square collocation method. The computational efficiency of this approach enables the inclusion of uncertainty statistics in the nonlinear programming optimization process. As such, new design questions related to uncertain dynamical systems can now be answered through the new framework. Specifically, this work presents the new framework through an inverse dynamics formulation where deterministic state trajectories are prescribed and uncertain actuator inputs are quantified. The benefits of the ability to quantify the resulting actuator uncertainty are illustrated in a time optimal motion planning case-study of a serial manipulator pick-and-place application. The resulting design determines a feasible time optimal motion plan—subject to actuator and obstacle avoidance constraints—for all possible systems within the probability space. The forward dynamics formulation (using deterministic actuator inputs and uncertain state trajectories) is presented in a companion paper.
Experimental Validation of the 2D Meshless Random Grid Method
Authors: Iliopoulos Athanasios , Michopoulos John G. , Orifici Adrian C. , Thomson Rodney S.
Published: June 2012

This paper presents the first systematic effort for the experimental validation of the 2D Meshless Random Grid Method (MRGM) for the full field measurement of displacement and strain fields. Although the MRGM has been demonstrating very promising characteristics of accuracy, performance and ease of application based on previously conducted sensitivity analysis supported by virtual data, extensive experimental validation was not available until now. This work comes to fill this gap and presents preliminary validation results against strain gauge data collected from open hole tension experiments of composite specimens. In addition, strain and displacement field verification is performed by comparison studies with finite element analysis results.
Optimum Trajectory Planning for Redundant and Hyper-Redundant Manipulators Through Inverse Dynamics
Authors: Ayten Kagan K. , Sahinkaya M. Necip , Iravani P.
Published: June 2012

This paper presents a method to develop minimum energy trajectories for redundant/hyper-redundant manipulators with pre-defined kinematic and dynamic constraints. The optimal trajectory planning uses fifth order B-spline functions to represent the Cartesian coordinates of the end-effector and angles of the redundant links. The actuator torques are considered for the formulation of the cost function. Calculation of the cost function is carried out by using an inverse dynamic analysis. The system constraints are handled within the cost function to avoid running the inverse dynamics when the constraints are not satisfied. A novel virtual link concept is introduced to replace all the redundant links to eliminate physicaly impossible configurations before running the inverse dynamic model. The process is applicable to hyper redundant manipulators with large number of links. The proposed scheme is verified with computer simulations based on a 5-link planar redundant manipulator.
Content-Based Support for Annotating New Content in a Wiki for Shape Memory Technology
Authors: Theiß Ralf , Langbein Sven , Sadek Tim
Published: June 2012

The application of new technologies such as Shape Memory Technology (SMT) is a challenging task for product developers. On the one hand, product developers have to be aware of this new technology and its potential uses. On the other hand, they have to be enabled to apply SMT in their products. Therefore, the Special Research Field SFB459 – Shape Memory Technology provides a considerable amount of its scientific results in a wiki-based system. This system is accessible online to interested product developers. Comprehensive information about basic material research as well as about the application of SMT is available in the system. However, the usability of this information is limited especially by the complex hierarchical structure of the content, which is due to the different knowledge levels and disciplines of the users. To solve these problems, a new approach has been developed to improve the usability of the wiki and of the information provided. This approach replaces the hierarchical structure by a non-hierarchical collection of articles, which have been connected and rendered accessible by a set of annotations. These annotations allow the application of different methods for inserting and retrieving information. The users are supported by an assistance system which provides methods for the semi-automatic annotation of articles. This system recommends possible annotations using different content-based approaches to text analysis. The evaluation and application of different content-based approaches to a domain-specific wiki for SMT with a comparatively small number of articles is focused in this paper.
Experimental Dynamical Characterization of Beach Tennis Rackets by Modal Analysis
Authors: Mucchi Emiliano
Published: June 2012

The term sweet spot is used for tennis racket in describing that point or region where the ball should be hit for optimal results. From a vibration standpoint, the sweet spot is determined by the location of the nodal lines across the racket head. In this paper, several methodologies based on modal analysis techniques are explored in order to estimate such a sweet spot for a beach tennis racket. Particular attention was addressed in the detection of the optimal boundary conditions to which the beach tennis racket should be constrained. It is the first time this item is dynamically characterized by experimental techniques. Test results are presented and the sweet spot related to minimal vibration perception is identified for a beach tennis racket. A further experimental study is also carried out in order to identify the Maximum Coefficient of Restitution in beach tennis rackets; this coefficient is related to racket efficiency and characterized by a minimum absorption of the ball incident kinetic energy by the racket. This study could be useful for design, development and practical use of beach tennis rackets.
A Framework for Non-Nominal Visualization and Perceived Quality Evaluation
Authors: Wagersten Ola , Forslund Karin , Wickman Casper , So¨derberg Rikard
Published: June 2012

Perceived Quality clusters different aspects that influence the customer’s perception of non-functional quality on a product that are perceive through senses. All together those aspects and the harmony between them reflect the producer’s ability to control product parameters and thereby also mirror the functional quality of the product. High Perceived Quality cannot be added to the product at the end of the developing process. Project prerequisites, system solution, factory capability etc. are criterion to succeed. Therefore, it is important to be able to evaluate Perceived Quality early in the process when product system solutions and architecture are defined, although data maturity is low. This paper presents a comprehensive framework to manage and support evaluation of Perceived Quality aspects in a product development process. The framework is based on an industrial process in combination with recent research within the field. The framework focuses on activities that can be performed at different stages in the developing process based on maturity of the CAD or styling data. For example, if the styling data is divided into different components by split-lines it has reached higher level of maturity then styling data that not has been divided. Consequently, the choice of applied method is based on data maturity, regardless phase in the developing process. The framework contains methods based on several different simulation and analysis techniques. Design methods, Computer-Aided Tolerancing and FEA based non-rigid variation simulation are represented in the framework.
Design for Supply Chain Requirements: An Approach to Detect the Capabilities to Postpone
Authors: Brosch Max , Krause Dieter
Published: June 2012

Different development trends pose new challenges for companies. They often meet these challenges by developing new product variants. Internally, this leads to an increased complexity, both at the product and at the supply chain level, which are mutually connected. The existing approaches and methods of complexity management only focus on one of the observed levels and do not consider the mutual connectivity. Modularity and platform strategy are the most common approaches to reduce the complexity at the level of product design. At the level of supply chain processes, the most common strategies are postponement and process commonality. These approaches do not support selecting the optimal complexity management strategy as for example the proper level of modularization or the optimal depth of added value (postponement). Therefore, this paper presents an approach to detect the capabilities to postpone, which accomplishes more transparency about the supply chain processes and the opportunities and capabilities of the individual supply chain stations. This transparency supports the supply chain management as well as the product development in the reduction of internal complexity.