bluuebunny/crossref_metadata_2025 huggingface dataset:
Design, Analysis, and Tests of Differential Planetary Gear System for Open Rotor Power Gearbox (Final Report)
Authors: Sato Kazuhiro , Goi Tatsuhiko , Taguchi Toshiaki , Nishida Tooru , Arisawa Hidenori , Matsuoka Tetsuya , Imai Hideyuki , Banno Takahiko
Published: January 2016

The requirements for general aero-engines are becoming increasingly severe to achieve higher efficiency and lower emission. The Open Rotor Engine is one of the next-generation aero-engine concepts expected to satisfy these requirements. The Open Rotor Engine has a set of counter-rotating unducted fans to increase the propulsion efficiency. A 20,000 hp class differential planetary gear system is suitable for driving these counter-rotating fans. To realize a 20,000 hp class differential planetary gear system, there are some design challenges to be accomplished 1) large power (20,000 hp class), 2) sufficiently small and light to fit an engine (envelope), 3) high transmission efficiency over 99.5%, 4) precise misalignment control for gears and bearings, 5) high reliability (50,000 hour MTBF). At Kawasaki Heavy Industries, Ltd., development of the Open Rotor Power Gearbox started in 2007. The purpose of this development is to establish a design practice for the 20,000 hp class gear system and to demonstrate that its readiness level (TRL) is appropriate for whole-engine development. In this development, various state-of-the-art simulation technologies such as lube oil flow CFD, FEA, and tooth contact analysis were fully utilized to optimize the design. Details of the design, fabrication, and validation tests of a full-scale prototype up to 2012 were presented at the IDTC/CIE in 2013. This paper presents a summary of the previous activity and subsequent works and achievements as a final report.
Towards Real-Time Composite Material Characterization Using Surrogate Models and GPGPU Computing
Authors: Steuben John , Michopoulos John G. , Iliopoulos Athanasios , Turner Cameron
Published: January 2016

In this paper we address the particular need for high-speed or “real-time” characterization of realistic anisotropic material systems such as laminated composites. This is driven by the desire to dynamically alter the loading paths applied by a multiaxial robotic test frame during the testing of a specimen, so that strain states are developed in the specimen in a manner that activates the maximum excitation of the specimen’s constitutive properties. In order to achieve this goal, we present an evolutionary adaptation of earlier work into computationally efficient material characterization using response-surface surrogate models. This approach is enhanced by the adoption of highly-parallel General Purpose Graphics Processing (GPGPU) computing. We discuss the challenges of adapting the characterization problem for GPGPU computing, particularly in terms of parallelization, synchronization, and approximation. Two parallelized algorithms for characterization are developed, and the merits of each are discussed. We then demonstrate validation results on a simple linear-elastic material system, and present statistical data which demonstrate the robustness of the approach in the presence of experimental noise. We conclude with remarks regarding the performance of the GPGPU-enabled characterization algorithm, and its applicability to more complex material systems.
Geometric Design of a Passive Mechanical Knee for Lower Extremity Wearable Devices Based on Anthropomorphic Foot Task Geometry Scaling
Authors: Ghosh Shramana , Robson Nina , McCarthy J. M.
Published: January 2016

The standard recovery treatment for ankle and lower leg injuries consists of using underarm crutches. Hands-free crutches have recently emerged as a more comfortable, natural and energy efficient alternative. However in the currently available devices such as the iWalk-Free (iWALKFree, Inc., USA) the lack of a knee joint results in abnormal motion pattern at the hip and pelvic joints to ensure foot clearance during the swing phase of the gait. To address this shortcoming, the paper describes the kinematic synthesis of a planar passive four-bar linkage that can be used as a mechanical knee in lower limb exoskeletons and other wearable devices. The knee design is based on anthropomorphic foot walking trajectory obtained from optical motion capture system. The task geometry at the foot, related to the contact and curvature constraints between the foot and the ground at two critical positions ‘heel strike’ and ‘toe off’ is scaled to the knee level. Velocity and acceleration specifications compatible with the contact and curvature constraints assist in defining the synthesis equations for the knee design. A working prototype of a passive wearable crutch substitute that incorporates the mechanical knee shows the applicability of the proposed technique.
Toward Customer Needs Cultural Risk Indicator Insights for Product Development
Authors: Van Bossuyt Douglas L. , Dean Jered
Published: January 2016

As the availability and affordability of consumer products continues to increase around the world, consumers — especially those in developing countries and living on less than $10/day — will express more discerning in their tastes and preferences. Design teams have already been operating in design for the developing world contexts for many years and more are moving into the arena on a regular basis. Many designers do not have cultural knowledge of the customers cultures they are designing for. Cultural ignorance can lead to misinterpretation of customer needs that can lead to products that do not satisfy customer needs and results in disappointed customers, low sales figures, and a frustrated design team. The Customer Needs Cultural Risk Indicator (CNCRI) method introduced in this paper provides a method for design teams to rapidly analyze customer needs for “Risk Indicators” in customer needs based upon cultural differences between the customers and the design team. By understanding early on in the design process where a lack of cultural knowledge may be a risk to the design, the design team can make informed decisions on how to satisfy customer needs effectively.
A Meso-Scale Rolling-Contact Gripping Mechanism for Robotic Surgery
Authors: Grames Clayton L. , Tanner Jordan D. , Jensen Brian D. , Magleby Spencer P. , Steger John Ryan , Howell Larry L.
Published: January 2016

A new, compact 2 degree-of-freedom mechanism 4.1 mm in diameter suitable for robotically controlled surgical operations is presented. Current commercially available robotically controlled instruments achieve high dexterity defined by three degrees of freedom and relatively confined swept volume at just under 1 cm in diameter. Current smaller diameter instruments result in high part count and large swept volumes (less dexterity). A meso-scale rolling contact gripping mechanism is proposed as an alternative. The manufacturing of the parts is made feasible by Metal Laser Sintering, which can produce parts that are difficult to replicate with traditional manufacturing methods. The resulting instrument has only 6 parts and a small swept volume. Instrument actuation and control by a surgical robotic system is demonstrated.
Influence of Grease Characteristics on Gear Friction Loss
Authors: Matsumoto Yoichi , Houjoh Haruo
Published: January 2016

In a previous study, we analyzed the mechanical loss factors of a small-sized geared motor comprising an induction motor and a parallel gear reducer. The load dependent loss is mainly caused by gear mesh friction, which is related to grease characteristics.

This study investigates how the grease characteristics influence the friction loss of the gear mesh. The important grease characteristics are the cone penetration, kinematic viscosity, type of base oil, and type of thickener.

The loss of gear mesh friction was evaluated in terms of the average friction coefficient between the gear teeth and was found to be unrelated to the cone penetration and kinematic viscosity of the base oil. The average friction coefficient of grease combined with lithium soap/poly urea and mineral base oil was 0.09–0.11; when combined with aluminum complex soap and synthetic base oil, the friction coefficient reduced to 0.07–0.08.
A Comprehensive Reliability Allocation Method of Feed Mixers Based on Fuzzy Synthetic Assessment
Authors: Yang Dong , Sun Yu , Wu Kai
Published: January 2016

To solve the problem that there are many factors influencing the reliability allocation of feed mixers, and some of which are difficult to analyze quantitatively, a comprehensive reliability allocation method is researched using triangular fuzzy number, fuzzy synthetic assessment and analytic hierarchy process. In this paper, a reliability allocation model is proposed for feed mixers, which considered several influence factors, and used triangular fuzzy number instead of real number to express uncertain information. It could make use of the reliability test information and experts’ experience comprehensively. Finally, the application of this method is illustrated with an example, and the result showed that the allocation method is feasible and effective for the reliability allocation of feed mixers.
Image Guided Automated Non-Prehensile Magnetic Micromanipulation of Cells
Authors: Das Akash , Thakur Ajay D. , Thakur Atul
Published: January 2016

Biomedical applications like cell manipulation and targeted drug delivery require automated micro-manipulation of biological material. Magnetic micro-manipulation has high actuation speed and minimal adverse effect on cell viability. Ferromagnetic particles, actuated via magnetic field, are used to push a target cell. The process is however cumbersome therefore require automation. This paper reports design, fabrication, and control of an image guided automated non-prehensile magnetic micromanipulation system. The developed system consists of ferromagnetic microspheres (henceforth referred to as microbots) which are actuated via independently controlling currents in four solenoids placed in a quadrupole configuration. We use image based localization for determining the microbot and target cell locations. We developed feedback planner which invokes either of the two maneuvers, namely, push or align to move microbot in order to push the cell towards the goal location. Instead of customize microtools we use simple spherical shaped microbots for pushing target cells.
Comparison of Four Numerical Schemes for Isoperimetric Constraint Fractional Variational Problems With A-Operator
Authors: Pandey Rajesh K. , Agrawal Om P.
Published: January 2016

This paper presents a comparative study of four numerical schemes for a class of Isoperimetric Constraint Fractional Variational Problems (ICFVPs) defined in terms of an A-operator introduced recently. The A-operator is defined in a more general way which in special cases reduces to Riemann-Liouville, Caputo, Riesz-Riemann-Liouville and Riesz-Caputo, and several other fractional derivatives defined in the literature. Four different schemes, namely linear, quadratic, quadratic-linear and Bernsteins polynomials approximations, are used to obtain approximate solutions of an ICFVP. All four schemes work well, and when the number of terms approximating the solution are increased, the desired solution is achieved. Results for a modified power kernel in A-operator for different fractional orders are presented to demonstrate the effectiveness of the proposed schemes. The accuracy of the numerical schemes with respect to parameters such as fractional order α and step size h are analyzed and illustrated in detail through various figures and tables. Finally, comparative performances of the schemes are discussed.
Casimir and Van Der Waals Effects on Parametric Resonance of Bio-NEMS Circular Plate Resonators
Authors: Caruntu Dumitru I. , Oyervides Reynaldo
Published: January 2016

This paper deals with Casimir and van der Waals effects on the frequency response of parametric resonance of electrostatically actuated NEMS circular plates for bio-sensing applications. The bio-NEMS resonator consists of a clamped circular elastic plate over a fixed electrode plate. A soft AC voltage of frequency near natural frequency between the plates gives an electrostatic force that leads the elastic plate into vibration which leads to parametric resonance that can be used afterwards for biosensing purposes. Frequency response and the effects of Casimir, and van der Waals forces on the response are reported.
Feature-Based Approach for Integration of Life Cycle Assessment With Product Development
Authors: Tao Jing , Yu Suiran , Peng Qingjin
Published: January 2016

This paper aims to develop a methodology for the integrating LCA with product development to enhance the environment-orientated design and manufacturing. First, the LCA feature view model is developed to address the scheme of representing life cycle processes, life cycle inventory analysis and to enable the exchange of valuable data between the LCA and computer aided engineering systems for sustainability improvements. Based on the feature view model, the framework of feature based LCA is then proposed. The LCA study of welding is presented to demonstrate the proposed approach.
A Geometric Derivation of the Equations of Motion for Mechanical Systems With Scleronomic Constraints
Authors: Natsiavas Sotirios , Paraskevopoulos Elias
Published: January 2016

A new set of equations of motion is presented for a class of mechanical systems subjected to equality motion constraints. Specifically, the systems examined satisfy a set of holonomic and/or nonholonomic scleronomic constraints. The main idea is to consider the equations describing the action of the constraints as an integral part of the overall process leading to the equations of motion. The constraints are incorporated one by one, in a process analogous to that used for setting up the equations of motion. This proves to be equivalent to assigning appropriate inertia, damping and stiffness properties to each constraint equation and leads to a system of second order ordinary differential equations for both the coordinates and the Lagrange multipliers associated to the motion constraints automatically. This brings considerable advantages, avoiding problems related to systems of differential-algebraic equations or penalty formulations. Apart from its theoretical value, this set of equations is well-suited for developing new robust and accurate numerical methods.
Numerical Integration of a New Set of Equations of Motion for Mechanical Systems With Scleronomic Constraints
Authors: Potosakis Nikolaos , Paraskevopoulos Elias , Natsiavas Sotirios
Published: January 2016

Some new theoretical and numerical results are presented on the dynamic response of a class of mechanical systems with equality motion constraints. At the beginning, the equations of motion of the corresponding unconstrained system are presented, first in strong and then in a weak form. Next, the formulation is extended to systems with holonomic and/or nonholonomic constraints. The formulation is based on a new set of equations of motion, represented by a system of second order ordinary differential equations (ODEs) in both the coordinates and the Lagrange multipliers associated to the motion constraints. Moreover, the position, velocity and momentum type quantities are assumed to be independent, forming a three field set of equations. The weak formulation developed was first used to cast the equations of motion as a set of first order ODEs in the coordinates and the corresponding momenta. Then, the same formulation was also employed as a basis for producing a suitable time integration scheme for the systems examined. The validity and efficiency of this scheme was tested and illustrated by applying it to a number of characteristic example systems.
A Modular Product Design Method to Improve Product Social Sustainability Performance
Authors: Ma Junfeng , Kremer Gül E. Okudan
Published: January 2016

Sustainability has been the emphasis of intense discussion over recent decades, but mostly focused on addressing critical aspects of environmental issues. An increasing awareness of social responsibilities and ever-shifting customer requirements have led manufacturers to consider social sustainability during the design phase in tandem with addressing environmental concerns; thus, design for social sustainability has evolved as a new product design direction. Modular product design (MPD), has been widely used in both academia and industry because of its significant benefits in design engineering. Because of the potential synergy, investigating design for social sustainability in association with MPD holds promise as a field of investigation. In this paper, we introduce a novel MPD approach that uses the elements of key component specification and product impact on social sustainability. The key components carry core technologies or have the highest sustainability effects in a product (i.e., the most costly or environmentally polluting parts). Product competitiveness strongly relies on a few key components that should be a focal point during product development. However, to the best of our knowledge, key components have not been well addressed in modular product design. In this paper, we employ labor time as an indicator to measure social sustainability. A heuristic-based clustering algorithm with labor time optimization is developed to categorize components into modules. A coffee-maker case study is conducted to demonstrate the applicability of the proposed methodology.
Maximum Power Point Tracking of Proton Exchange Membrane Fuel Cell With Fractional Order Filter and Extremum Seeking Control
Authors: Liu Jianxin , Zhao Tiebiao , Chen YangQuan
Published: January 2016

Proton Exchange Membrane FC (PEMFC) is widely recognized as a potentially renewable and green energy source based on hydrogen. Maximum power point tracking (MPPT) is one of the most important working conditions to be considered. In order to improve the searching performance such as convergence and robustness under disturbance and uncertainty, a kind of fractional order low pass filter (FOLPF) is applied for the MPPT controller design based on general Extremum Seeking Control (ESC). The controller is designed with FOLPF and high pass filter (HPF) substituting the normal LPF and HPF in the original ESC design. With this FOLPF ESC, better convergence and smooth performance is gained while maintaining the robust specifications. Simulation results are included to validate the proposed new FOLPF ESC scheme under disturbance and comparisons between FOLPF ESC and general ESC method are also provided.
Identifying Possible Patient Slips and Falls Using Motion Capture Experiments
Authors: Cloutier Aimee , Yang James , Pati Debajyoti , Valipoor Shabboo , Snailer Brandon , Hollers Jerrod
Published: January 2016

The Centers for Disease and Control report that falls are the most common cause of injury in older adults. Moderate to severe fall-related injuries significantly interfere with independent living and reduce quality of life, and it is necessary to prevent these falls whenever possible. The present study seeks to identify factors within a hospital bedroom and bathroom setting that may lead to falls. A motion capture experiment was conducted in a laboratory setting on thirty subjects over the age of seventy using one bedroom and two bathroom mockups designed to match the dimensions and layout of a representative room drawn from the archives of a large healthcare design firm. Data were post processed using Cortex and Visual3D software. A potential fall was defined as a period of time during which the jerk trajectory of the upper body’s center of mass remained consistently high. Preliminary results suggest that falls are more likely to occur when a patient is reaching, taking backwards steps, or turning. Future work includes locating each potential fall in a video recording to be analyzed by healthcare professionals including healthcare designers, clinicians, and a kinesiology expert. Identifying potential falls may lead to safer designs for hospital bedrooms and bathrooms and improved education for elderly adults about how to prevent falls.
Large-Curvature Deployable Developable Structures via Lamina Emergent Arrays
Authors: Nelson Todd G. , Lang Robert J. , Magleby Spencer P. , Howell Larry L.
Published: January 2016

A method is presented utilizing networks of lamina emergent joints, known as lamina emergent arrays, to accommodate large-curvature developable structures that are also deployable. By exploiting the ruling lines in developable surfaces, this method enables developable structures that can be manufactured with two-dimensional geometry and yet have a greater range of elastic motion than is possible with a solid sheet of material. A mathematical model is developed to describe the resulting stiffness of the structure employing the lamina emergent arrays and equations are derived to facilitate stress analysis of the structure. Finite element results show the sensitivity of alignment of the elements in the array to the stress present in the developed structure. A specific technique for creating an array pattern for conical developable surfaces is described. Examples of developable structures, including curved-fold origami models transitioned to thick materials, are also examined.
Multistable Behavior of Compliant Kaleidocycles
Authors: Evans Thomas A. , Rowberry Brett G. , Magleby Spencer P. , Howell Larry L.
Published: January 2016

We present an analysis of the compliant kaleidocycle, a mechanism which, unlike other compliant mechanisms, may undergo continuous rotation. We analyze the strain energy characteristics of this mechanism during its motion and show that by varying the stiffness and orientation of the flexures, kaleidocycles may be designed to achieve customizable multistable behavior. These devices may be designed to include up to four distinct stable equilibrium positions and may also include regions of neutral stability.
On-Road Evaluation of Energy Cost on Cycling: A Case Study for Analyzing Tire Pressure Influence
Authors: Roa Sergio Daniel , Muñoz Luis Ernesto
Published: January 2016

This work presents a methodology for the evaluation of energy cost on cycling through on-road tests. The proposed methodology consists on the measurement of the power delivered by the cyclist on the pedals when riding on a real circuit. The aim of the methodology is to generate indexes for the direct evaluation of the effect on energy cost generated by an arbitrary modification implemented on a bike. The modification can include the variation of multiple parameters. The proposed indexes for the evaluation of the energy cost are the mean input power and the mechanical work per distance during the test. The proposed methodology intends to evaluate the energy cost for a given bike-rider set on a given circuit.

A case study is presented for the evaluation of tire pressure influence on energy cost. For the application of the methodology, one cyclist rode on the circuit of interest with a set of different tire pressures. The power delivered by the cyclist was measured on the pedals. Several tests were conducted for each pressure in order to achieve a good level of significance. The results obtained for the case study with the proposed methodology are compared with the results of a method based on rolling resistance coefficients reported in literature.
A Shape-Controlled Compliant Microarchitectured Material
Authors: Shaw Lucas A. , Hopkins Jonathan B.
Published: January 2016

The purpose of this paper is to introduce a new kind of actively controlled microarchitecture that can alter its bulk shape through the deformation of compliant elements. This new type of microarchitecture achieves its reconfigurable shape capabilities through a new control strategy that utilizes linearity and closed-form analytical tools to rapidly calculate the optimal internal actuation effort necessary to achieve a desired bulk surface profile. The microarchitectures of this paper are best suited for high-precision applications that would benefit from materials that can be programmed to rapidly alter their surfaces/shape relatively small amounts in a controlled manner. Examples include distortion-correcting surfaces on which precision optics are mounted, airplane wings that deform to increase maneuverability and fuel efficiency, and surfaces that rapidly reconfigure to alter their texture. In this paper, the principles are provided for optimally designing 2D or 3D versions of the new kind of microarchitecture such that they exhibit desired material property directionality. The mathematical theory is provided for modeling and calculating the actuation effort necessary to drive these microarchitectures such that their lattice shape comes closest to achieving a desired profile. Case studies are provided to demonstrate this theory.
UAV-Based Wireless Telemetry System for the Estimation of Ship Air Wake Patterns
Authors: Kumar Anil , Ben-Tzvi Pinhas , Snyder Murray
Published: January 2016

This paper presents the development of a wireless instrumentation system for estimation of air turbulence patterns in real-time. The proposed system uses off-the-shelf RC helicopter flying in wind turbulent regions and uses the oscillations caused by wind gusts to measure turbulence. This paper presents the proposed system as a tool to measure off-board ship air wake patterns generated by a cruising naval patrol craft. Two aviation grade Inertial Navigation Systems (INS) with onboard filters are used in this system. These filters precisely measure the dynamics and the location of the helicopter with respect to the vessel. The data is then wirelessly transmitted to a base station on the vessel where Back Propagation neural networks are used to remove the effects of pilot inputs from vibrational data in real time to extract the oscillations caused by the turbulence alone. The system was tested in Chesapeake Bay in a wide range of wind conditions and the results are shown as air wake intensity patterns plotted on helicopter trajectory around the cruising vessel. The proposed system will be used for experimental validation of CFD models to predict ship air wakes.
Development of a Novel Coupling Mechanism for Modular Self-Reconfigurable Mobile Robots
Authors: Saab Wael , Ben-Tzvi Pinhas
Published: January 2016

This paper presents the development of a novel coupling mechanism for modular self-reconfigurable mobile robots. Modular self-reconfigurable mobile robotic systems consist of a large number of self-sufficient modules that can transform into various configurations. One of the most challenging tasks in this field is designing a reliable and flexible coupling mechanism that physically connects modules to form larger and more articulated structures to scale up locomotion and manipulation functions. In this research we propose GHEFT: a Genderless, High strength, Efficient, Fail-safe, and high misalignment Tolerant coupling mechanism that aids the process of self-reconfiguration, and self-repair. Many existing coupling mechanisms fail to possess these crucial design features. The proposed mechanism ensures an efficient and high strength connection due to non-back drivable actuation and specially designed clamping profiles that enables modules to tolerate large misalignments and engage/disengage without gender restrictions in the presence of one-sided malfunction; thus, increasing both the versatility and robustness of the entire robotic system. In this paper, misalignment analysis is performed to formulate simple relations based on clamping profile design parameters to achieve specific misalignment tolerances based on application requirements. These formulations are used to compute maximum misalignment tolerances. Dynamic simulations are then performed to determine maximum misalignment tolerance capabilities and verify computed tolerances.
A Numerical Algorithm to Initial Value Problem of Linear Caputo Fractional-Order Differential Equation
Authors: Bai Lu , Xue Dingyü
Published: January 2016

A numerical algorithm is presented to solve the initial value problem of linear Caputo fractional-order differential equations. Error analysis has been done to Taylor series algorithm, the reason has been found why the error of the algorithm is large, the condition of using Taylor series algorithm is presented. A new algorithm called exponential function algorithm is proposed based on the analysis. Nonzero initial value problem could be transformed into zero initial value problem. The obtained fractional-order differential equation is transformed into difference equation, the numerical solution can be found with closed form solution formula. The error of the numerical solution can be modified with prediction-correction algorithm.
The Generation Principle and Mathematical Models of Double-Enveloping Internal Gear Pairs
Authors: Li Xuan , Chen Bingkui , Wang Yawen , Sun Guohua , Lim Teik C.
Published: January 2016

In this paper, the planar double-enveloping method is presented for the generation of tooth profiles of the internal gear pair for various applications, such as gerotors and gear reducers. The main characteristic of this method is the existence of double contact between one tooth pair such that the sealing property, the load capacity and the transmission precision can be significantly improved as compared to the conventional configuration by the single-enveloping theory. Firstly, the generation principle of the planar double-enveloping method is introduced. Based on the coordinate transformation and the envelope theory, the general mathematical model of the double-enveloping internal gear pair is presented. By using this model, users can directly design different geometrical shape profiles to obtain a double-enveloping internal gear pair with better meshing characteristics. Secondly, to validate the effectiveness of the proposed model, specific mathematical formulations of three double-enveloping internal gear pairs which apply circular, parabolic and elliptical curves as the generating curves are given. The equations of tooth profiles and meshing are derived and the composition of tooth profiles is analyzed. Finally, numerical examples are provided for an illustration.
Kinematics Model for Tooth-Skipped Gear Honing
Authors: Yu Bo , Lin Jiachun , Shi Zhaoyao
Published: January 2016

As gears that have been honed offer excellent wear characteristics and are extremely quiet, gear honing has become an essential part in the production of high-speed transmissions. In this paper, a novel gear honing technology based on toothskipped gearing theory is proposed. So far, this theory has been used only in the gear dynamic integrated error measuring machine, which was invented by a Chinese engineer. It is the first time that the theory has been introduced into gear manufacturing. Firstly, the whole tooth-skipped honing process is analyzed by taking the rack and pinion as an example. Secondly, the kinematics model of relationship between the rack and the gear is established, which takes the rack addendum meshing process, the gear addendum meshing process and the involute meshing process into consideration. Finally, the boundary points of each process are analyzed. The velocity curve of the gear to be manufactured is obtained. Tooth-skipped gear honing as a gear fine finishing approach has high processing efficiency and can increase the gear quality.
Improvement of Strict LMI Admissibility Criteria of Singular Systems: Continuous and Discrete
Authors: Zhang XueFeng , Chen YangQuan
Published: January 2016

This brief note considers the solutions of LMIs in the criteria for admissibility for continuous singular systems and discrete singular systems. The new criteria are given which are strict LMI and do not involve equality constraint. The main trait of the criteria is that they simplify and improve the existing results. To judge the admissibility of singular systems, only the lest solved variable P is introduced without involving the additional matrix Q in the corresponding LMIs. With the brief and simple results of this paper, the numbers of solved matrices are reduced from a pair of matrices to just a matrix in which we can analyze singular systems with the completely consistent format as normal systems.
Regional Controllability of Anomalous Diffusion Generated by the Time Fractional Diffusion Equations
Authors: Ge Fudong , Chen YangQuan , Kou Chunhai
Published: January 2016

This paper is concerned with the investigation of the regional controllability of the time fractional diffusion equations. First, some preliminaries and definitions of regional controllability of the system under consideration are introduced, which promote the existence contributions on controllability analysis. Then we analyze the regional controllability with minimum energy of the time fractional diffusion equations on two cases: B ∈ L (Rm, L2 (Ω)) and B ∉ L (Lm, L2 (Ω)). In the end, two applications are given to illustrate our obtained results.
Multi-Freedom Planetary Transmission Scheme Based on Graph Theory of Topological Synthesis
Authors: Mu Dejun , Wang Huiying , Ding Huafeng , Liu Xiangwei , Zhang Xing
Published: January 2016

In order to enrich the synthesis theory of planetary gearbox and meet the needs of multiple gearshifts this paper proposes a comprehensive method for the planetary gear transmission. Based on the topological graph atlas, the kinematic chains of 9-link and 2 degrees of freedom are synthesized. By the topological graph selection principle and gear function diagram transformation principle, 6-speed transmission mechanisms are obtained.
Design of Scotch Yoke Mechanisms With Balanced Input Torque
Authors: Arakelian Vigen , Mkrtchyan Manuk
Published: January 2016

Input torque balancing through addition of an auxiliary mechanism is a well-known way to improve the dynamic behavior of mechanisms. One of the more efficient methods used to solve this problem is creating a cam-spring mechanism. However, the use of a cam mechanism is not always possible or desirable because of the wear effect due to the contact stresses and high friction between the roller and the cam.

This paper proposes to balance the input torque of Scotch yoke mechanisms without any auxiliary linkage just by adding linear springs to the output slider. It is shown that after cancellation of inertial effects the input torque due to friction in joints becomes constant, which facilitates the control of the mechanism. The efficiency of the suggested technique is illustrated via simulations carried out by using ADAMS software.
Stochastic Supply Networks Servicing Pre- and After-Sales Markets
Authors: Rezapour Shabnam , Singh Rahul , Allen Janet K. , Mistree Farrokh
Published: January 2016

In this paper, we consider a company including both a forward supply chain producing and supplying products to markets and an after-sales supply chain providing spare parts to fulfill after-sales commitments. Uncertainties in estimating product demand in the pre-markets, spare parts demands in the after-sales markets and qualified outputs of production facilities throughout these two chains are considered in this problem. Stochastic qualified output of production facilities are due to their imperfect productions systems. We show that uncertainties propagate and qualified flow depreciates by moving material, components and products from the upstream to the downstream of these supply chains and these phenomena should be quantified to determine the service levels of this company in the pre and after-sales markets. Reliable flows preserve chains’ service levels against uncertainties and their propagated effects. The consideration of the interactions of pre- and after-sales operations as concurrent planning of these two chains and considering both demand and supply side uncertainties and their propagated effects are the important contributions of this paper. Here, we propose a mathematical model for determining the best marketing strategies for this company (price, warranty length and service levels) and preserving reliable flow dynamics throughout the chains’ networks. The proposed model and its solution approach are tested using data from an engine production company. We derive some managerial insight by analyzing the correlations among the marketing strategies and how they affect each other.
A Multidimensional Network Approach for Modeling Customer-Product Relations in Engineering Design
Authors: Wang Mingxian , Chen Wei , Huang Yun , Contractor Noshir S. , Fu Yan
Published: January 2016

Analytical modeling of customer preferences in product design is inherently difficult as it faces challenges in modeling heterogeneous human behavior and product offerings. In this paper, the customer-product interactions are viewed as a complex socio-technical system and analyzed using social network theory and techniques. We propose a Multidimensional Customer-Product Network (MCPN) framework, where separate networks of “customers” and “products” are simultaneously modeled, and multiple types of relations, such as consideration and purchase, product associations, and customer social networks are considered. We start with the simplest unimodal network configuration where customer cross-shopping behaviors and product similarities are analyzed to inform designers about the implied product competition, market segmentation, and product positions in the market. We then progressively extend the network to a multidimensional structure that integrates customer preference decisions with product feature similarities to enable the modeling of preference heterogeneity, product association and decision dependency. Finally, social influences on new product adoption are analyzed in the same framework by introducing customer-customer relations together with other product-product and customer-product relations. Beyond the traditional network descriptive analysis, we employ the Exponential Random Graph Model (ERGM) as a unified statistical inference framework for analyzing multiple relations in MCPN to support engineering design decisions. Our approach broadens the traditional utility-based logit approaches by considering the dependency among product choices and the “irrationality” of customer behavior induced by social influence. While this paper is focused on presenting the conceptual framework of the proposed methodology, examples on customer vehicle preferences are presented to illustrate the progressive development of the MCPN framework from a simple unimodal configuration to a complex multidimensional structure.
Generalized Viscoelastic Material Design With Integro-Differential Equations and Direct Optimal Control
Authors: Gururaja Rao Lakshmi , Allison James T.
Published: January 2016

Rheological material properties are examples of function-valued quantities that depend on frequency (linear viscoelasticity), input amplitude (nonlinear material behavior), or both. This dependence complicates the process of utilizing these systems in engineering design. In this article, we present a methodology to model and optimize design targets for such rheological material functions. We show that for linear viscoelastic systems simple engineering design assumptions can be relaxed from a conventional spring-dashpot model to a more general linear viscoelastic relaxation kernel, K(t). While this approach expands the design space and connects system-level performance with optimal material design functions, it entails significant numerical difficulties. Namely, the associated governing equations involve a convolution integral, thus forming a system of integro-differential equations. This complication has two important consequences: 1) the equations representing the dynamic system cannot be written in a standard state space form as the time derivative function depends on the entire past state history, and 2) the dependence on prior time-history increases time derivative function computational expense. Previous studies simplified this process by incorporating parameterizations of K(t) using viscoelastic models such as Maxwell or critical gel models. While these simplifications support efficient solution, they limit the type of viscoelastic materials that can be designed. This article introduces a more general approach that can explore arbitrary K(t) designs using direct optimal control methods. In this study, we analyze a nested direct optimal control approach to optimize linear viscoelastic systems with no restrictions on K(t). The study provides new insights into efficient optimization of systems modeled using integro-differential equations. The case study is based on a passive vibration isolator design problem. The resulting optimal K(t) functions can be viewed as early-stage design targets that are material agnostic and allow for creative material design solutions. These targets may be used for either material-specific selection or as targets for later-stage design of novel materials.
Towards Pareto Optimization of Performance of a Generic Synchronizer of Transmission Systems
Authors: Berbyuk Viktor
Published: January 2016

Manual transmissions for passenger cars and trucks are equipped with synchronizer mechanisms. A synchronizer mechanism as a key component of a transmission system must be able to prevent transmission gears from shocking, reduce the noise and it has a great impact on driving comfort and transmission efficiency. Gear shifting improvement with respect to smooth, quick and energy efficient synchronizer’s performance is still an important issue for automotive industry.

A synchronization process comprises several phases within which presynchronization, main synchronization, pre-engagement and engagement phases can be recognized. Aiming an understanding of internal dynamics and existing possibilities for optimization of synchronization processes in transmission systems during the main synchronization phase an engineering model of a generic synchronizer mechanism is proposed. The synchronizer mechanism is modeled by a contacting triple-body system consisting of the selector sleeve, the blocker ring and the gearwheel. The algorithm has developed to solve the direct dynamics synchronization problem for the generic synchronizer mechanism. By using the developed algorithm the rotational motion of the contacting triple-body system and the synchronizing torques between contacting interfaces are determined for given vehicle resistance torque, the drag torque, and the control torque applied to the selector sleeve that all together satisfy the equations of motion and guarantee synchronization of the rotational speeds of the sleeve, the blocker ring and the gearwheel for the final time. It is shown that the solution to the direct dynamics synchronization problem for the generic synchronizer mechanism is not unique and it allows formulation different optimization problems.

Mathematical statement of multi-objective Pareto optimal control problem for synchronizer mechanism is given. Within the proposed model of the generic synchronizer mechanism the time-comfort Pareto optimal control problem is considered. Assuming that the resistance torque on the synchronizer owing to the vehicle inertia, the drag torque, and the synchronizing torques at the contacting interfaces are substantially constant during the main phase of a synchronization process, the solution to the time-comfort Pareto optimal control problem has been obtained.

It was shown that there exist the external control torque (or shift force) applied to the selector sleeve such that the synchronization of rotational speeds of the sleeve, the blocker ring and the gearwheel is guaranteed and the synchronization process is optimal both with respect to minimal possible synchronization time as well as lowest possible inertial load acting on the synchronizer mechanism. Analysis of the obtained Pareto solution is presented.
A Reduction Methodology Using Free-Free Component Eigenmodes and Arnoldi Enrichment
Authors: Tournaire Hadrien , Renaud Franck , Dion Jean-Luc
Published: January 2016

In order to perform faster simulations, the model reduction is nowadays used in industrial contexts to solve large and complex problems. However, the efficiency of such an approach is sometimes cut by the interface size of the reduced model and its reusability.

In this article, we focus on the development of a reduction methodology for the build of modal analysis oriented and updatable reduced order model whose size is not linked to their contacting interface. In order to allow latter model readjusting, we impose the use of eigenmodes in the reduction basis. Eventually, the method introduced is coupled to an Arnoldi based enrichment algorithm in order to improve the accuracy of the reduced model produced.

In the last section the proposed methodology is discussed and compared to the Craig and Bampton reduction method. During this comparison we observed that even when not enriched, our work enables us to recover the Craig and Bampton accuracy with partially updatable and smaller reduced order model.
Design and Optimization of Powertrain Using Hybrid Planetary Gearbox for Formula Student Vehicle
Authors: Makhija Gagan , Mahajan Manthan , Bansod Nilesh , Bakshi Soovadeep
Published: January 2016

Race cars are known for their brilliant acceleration as well as cornering performance. This requires optimization of each and every component of the car to shed every ounce of extra weight while maximizing the performance. This paper focuses on optimization of the powertrain of a Formula Student electric vehicle. The electric vehicle in question is a Formula style rear-wheel driven electric single person race car. The rear wheel drive is achieved with separate motors for each wheel controlled by electronic differential. Extensive research has been done in the area of gear design and several standards have been set. This paper follows the AGMA 2001-D04 standard as given in Shigley’s Mechanical Engineering Design [4]. A planetary gearbox was developed for a Formula Student vehicle with permanent magnet DC motor by Bakshi[2] et al. This paper tries to optimize the planetary gearbox and considers other suitable designs.