bluuebunny/crossref_metadata_2025 huggingface dataset:
Artificial Neural Network to Predict Patient Body Circumferences and Ligament Thicknesses
Authors: Vaughan Neil , Dubey Venketesh N. , Wee Michael Y. K. , Isaacs Richard
Published: February 2014

An artificial neural network has been implemented and trained with clinical data from 23088 patients. The aim was to predict a patient’s body circumferences and ligament thickness from patient data. A fully connected feed-forward neural network is used, containing no loops and one hidden layer and the learning mechanism is back-propagation of error. Neural network inputs were mass, height, age and gender. There are eight hidden neurons and one output. The network can generate estimates for waist, arm, calf and thigh circumferences and thickness of skin, fat, Supraspinous and interspinous ligaments, ligamentum flavum and epidural space. Data was divided into a training set of 11000 patients and an unseen test data set of 12088 patients. Twenty five training cycles were completed. After each training cycle neuron outputs advanced closer to the clinically measured data. Waist circumference was predicted within 3.92cm (3.10% error), thigh circumference 2.00cm, (2.81% error), arm circumference 1.21cm (2.48% error), calf circumference 1.41cm, (3.40% error), triceps skinfold 3.43mm, (7.80% error), subscapular skinfold 3.54mm, (8.46% error) and BMI was estimated within 0.46 (0.69% error). The neural network has been extended to predict ligament thicknesses using data from MRI. These predictions will then be used to configure a simulator to offer a patient-specific training experience.
Preference Construction, Sequential Decision Making, and Trade Space Exploration
Authors: Miller Simon W. , Simpson Timothy W. , Yukish Michael A. , Bennett Lorri A. , Lego Sara E. , Stump Gary M.
Published: February 2014

This paper develops and explores the interface between two related concepts in design decision making. First, design decision making is a process of simultaneously constructing one’s preferences while satisfying them. Second, design using computational models (e.g., simulation-based design and model-based design) is a sequential process that starts with low fidelity models for initial trades and progresses through models of increasing detail. Thus, decision making during design should be treated as a sequential decision process rather than as a single decision problem. This premise is supported by research from the domains of behavioral economics, psychology, judgment and decision making, neuroeconomics, marketing, and engineering design as reviewed herein. The premise is also substantiated by our own experience in conducting trade studies for numerous customers across engineering domains. The paper surveys the pertinent literature, presents supporting case studies and identifies use cases from our experiences, synthesizes a preliminary model of the sequential process, presents ongoing research in this area, and provides suggestions for future efforts.
Planar, Higher Variable Joints for Reconfigurable Mechanisms
Authors: Slaboch Brian J. , Voglewede Philip A.
Published: February 2014

This paper introduces planar, higher variable joints as essential components of reconfigurable mechanisms that change topology due to a joint geometry change. Higher variable joints are higher pair equivalent lower pairs that are geometrically different. It will be shown that 2nd order effects, or surface curvature, of higher variable joints is critical to achieve a particular joint motion. A practical application of higher variable joints will also be presented.
The Design of a Fully Compliant Statically Balanced Mechanism
Authors: Merriam Ezekiel G. , Colton Mark , Magleby Spencer , Howell Larry L.
Published: February 2014

This paper describes a fully compliant statically balanced mechanism that can undergo greater than 100° of motion. Because compliant mechanisms achieve their motion from the deflection of their constituent members, there is some strain energy associated with actuated positions. By introducing an appropriate preload, strain energy can be held constant. This can reduce or nearly eliminate the input force required from the actuating device. This paper describes the statically balanced concept and demonstrates its optimization, testing, and implementation for a haptic pantograph mechanism. The statically balanced properties of the constituent mechanisms result in an assembly with two balanced degrees of freedom.
Fast Online-Implementable Sub-Optimal Energy Management of a Power-Split Hybrid Electric Vehicle
Authors: Dong Jian , Cheng Rui , Dong Zuomin , Crawford Curran
Published: February 2014

The current focus of HEV controller design is on the development of real-time implementable energy management strategies that can approximate the global optimal solution closely. In this work, the Toyota Prius power-split hybrid powertrain is used as a case study for developing online energy management strategy for hybrid electric vehicle.

The power-split hybrid powertrain combines the advantages of both the series and parallel hybrid powertrain and has been appealing to the auto-makers in the past years. The addition of two additional electric machines and a Planetary Gear Sets (PGS) allows more flexibility in terms of control at some cost of complexity.

A forward-looking dynamic model of the power-split powertrain system is developed and implemented in Simulink first. An optimal control problem is formulated, which is further reduced to an optimal control problem with a single-variable objective function and a single-state subject to both dynamic constraint and boundary constraint. The reduced optimal control problem is then solved by an on-line (real-time) implementable approach based on Pontryagin’s Minimum Principal (PMP), where the costate p is adapted based on SOC feedback.

Simulation results on standard driving cycles are compared using the proposed optimal control strategy and a rule-based control strategy. The results have shown significant improvement in fuel economy comparing to the baseline vehicle model, and the proposed online (real-time) PMP control algorithm with an adaptive costate p is very close to the optimal PMP solution with a constant costate. The proposed optimal control has a fast computation speed and calculates the optimal decision “dynamically” without the necessity of knowing future driving cycle information and can be practically implemented in real-time.
Multi-Quadrant Surgical Robot for Single Incision Laparoscopic Colectomy
Authors: Markvicka E. J. , McCormick R. L. , Frederick T. P. , Bartels J. R. , Farritor S. M. , Oleynikov D.
Published: February 2014

Colorectal surgery is an area of active research within general surgery. However, over 80% of these procedures currently require an open surgery based on the size and location of the tumor. The current state-of-the-art surgical instruments are unintuitive, restricted by the incision site, and often require timely repositioning tasks during complex surgical procedures. A multi-quadrant miniature in vivo surgical robot has been developed to mitigate these limitations as well as the invasiveness of colorectal procedures. By reducing invasiveness, the patient benefits from improved cosmetics, decreased postoperative pain, faster recovery time, and reduced financial burden. A paradigm shift in invasiveness is often inversely proportional to surgeon benefits. Yet, through the use of a robotic device, the surgeon benefits from improved ergonomics, intuitive control, and fewer required repositioning tasks. This paper presents a two armed robotic device that can be controlled from a remote surgical interface. Each arm has six internally actuated degrees of freedom, decoupling the system from the incision site. Each arm is also equipped with a specialized interchangeable end effector. For the surgical procedure, visual feedback is provided through the use of a standard laparoscope with incorporated light source. The robotic device is introduced into the abdominal cavity through a hand-assisted laparoscopic surgery (HALS) port that is placed within the navel. The device is then grossly positioned to the site of interest within the abdominal cavity through the use of a protruding rod that is rigidly attached to each arm. The surgeon can then begin to manipulate tissue through the use of the surgical interface that is remotely located within the operating room. This interface is comprised of a monitor to provide visual feedback, foot pedals to control the operational state of the device, and two haptic devices to control the end point location of each arm and state of the end effectors.
Task Driven Unified Synthesis of Planar Four-Bar and Six-Bar Linkages With Revolute and Prismatic Joints for Five Position Synthesis
Authors: Zhao Ping , Purwar Anurag , Ge Q. J.
Published: February 2014

This paper deals with the problem of integrated joint-type and dimensional synthesis of planar four-bar and six-bar linkages with revolute (R) and prismatic (P) joints for guiding through five specified task positions of the end-effector. In a recent work, we developed a simple algorithm for analyzing a set of given task positions to determine all feasible planar dyads with revolute and/or prismatic joints that can be used to guide through the given positions. The current paper extends this algorithm to the integrated joint-type and dimensional synthesis of Watt I and II and Stephenson I, II, and III six-bar linkages with a combination of R and P joints. In the process, we developed a new classification for planar six-bar linkages according to whether the end-effector can be constrained by two dyads (Type I), one dyad (Type II), or no dyad (Type III). We demonstrate this task driven synthesis approach with three examples including a novel six-bar linkage for lifting an individual with age disability from seating position to standing position.
Towards a Formalization of Affordance Modeling in the Early Stages of Design
Authors: Cormier Phillip , Olewnik Andrew , Lewis Kemper
Published: February 2014

When developing an artifact, designers must first capture and represent consumer needs. These needs can then be transformed into system requirements or objectives. This paper proposes a formalized affordance-based method for capturing consumer needs which leverages previous work in the area of Affordance-based design. The creation of an affordance basis and a relational structure (the Desired Affordance Model) facilitates the use of affordances to represent consumer needs. This formalization has the potential to improve model quality and consistency, while managing model creation time. Further, this formalization imposes a level of abstraction which forces solution independence but is capable of capturing the large range of consumer needs.
Numerical Investigation of Rotating Nonlinear Energy Sink for Shock Mitigation
Authors: Al-Shudeifat Mohammad A. , Bergman Lawrence A. , Vakakis Alexander F.
Published: February 2014

Passive nonlinear targeted energy transfer (TET) is addressed here by investigating a lightweight rotating nonlinear energy sink (NES). The rotating sink mass has an essentially nonlinear inertial coupling with the two degree-of-freedom linear system (the primary test structure). The proposed rotating NES is numerically investigated where it is found to passively absorb and rapidly dissipate a considerable portion of the initial energy induced by impulse to the linear structure. The parameters of the rotating NES are optimized for the best performance in the vicinity of intermediate and high loads. The fundamental mechanism for significant energy transfer to the NES is its rotational mode; the oscillatory mode of the NES dissipates far less energy. The frequency-energy dependences are investigated through the frequency-energy plot (FEP). Early and strong resonance capture at the lowest modal frequency is observed between the rotator and the structure, at which a significant portion of the induced energy is transferred and dissipated by the rotator. The performance of this device is found to be comparable to existing, stiffness-based NES designs. However, this device is less complicated and more compact.
Comprehensive Product Platform Planning (CP3) for a Modular Family of Unmanned Aerial Vehicles
Authors: Chowdhury Souma , Maldonado Victor , Tong Weiyang , Messac Achille
Published: February 2014

The development of products with a modular structure, where the constituent modules could be derived from a set of common platforms to suit different market niches, provides unique engineering and economic advantages. However, the quantitative design of such modular product platforms could become significantly challenging for complex products. The Comprehensive Product Platform Planning (CP3) method facilitates effective design of such product platforms. The original CP3 method is however typically suitable for scale-based product family design. In this paper, we perform important modifications to the commonality matrix and the commonality constraint formulation in CP3 to advance its applicability to modular product family design. A commonality index (CI), defined in terms of the number of unique modules in a family, is used to quantify the commonality objective. The new CP3 method is applied to design a family of reconfigurable Unmanned Aerial Vehicles (UAVs) for civilian applications. CP3 enables the design of an optimum set of distinct modules, different groups of which could be assembled to configure twin-boom UAVs that provide three different combinations of payload capacity and endurance. The six key modules that participate in the platform planning are: (i) the fuselage/pod, (ii) the wing, (iii) the booms, (iv) the vertical tails, (v) the horizontal tail, and (vi) the fuel tank. The performance of each UAV is defined in terms of its range per unit fuel consumption. Among the best tradeoff UAV families obtained by mixed-discrete Particle Swarm Optimization, the family with the maximum commonality (CI = 0.5) required a 66% compromise of the UAVs’ range/fuel-consumption performance. The platform configuration corresponding to the maximum-commonality UAV family involved sharing of the horizontal tail and fuel tank among all three UAVs and sharing of the fuselage and booms among two UAVs.
Interpreting Design Structure in Patents Using an Ontology Library
Authors: Li Zhen , Tate Derrick
Published: February 2014

Patents contain valuable information for engineering design. However, the increasing number of annual patent publications makes it difficult for any individual designer to assimilate all up-to-date knowledge hidden in patent documents. In this paper, we proposed a computational approach to interpret design structure embedded in patent claims using pre-developed ontology libraries. The study combined natural language processing (NLP) techniques, text data-mining, ontological engineering, and our rule-based tree generation method. Data sources and adopted tools included online patent documents, knowledge gathered from engineering textbooks, WordNet, a part-of-speech tagger developed by the Stanford NLP group, and Graphviz. We showed that the framework proposed in the paper not only could help minimize manual work required for obtaining design structures but also enable automatic dissimilarity comparison between patents.
A Fully Parameterized Finite Element Model of a Grand Piano Soundboard for Sensitivity Analysis of the Dynamic Behavior
Authors: Mokdad Fatma , Missoum Samy
Published: February 2014

This work in progress aims at investigating the influence of several parameters on the modal behavior of a grand piano soundboard. The sensitivity analysis is made possible by the development of a fully parameterized Finite Element model of the soundboard which allows the user to modify most geometric and material parameters involved in its dynamic behavior. In addition, crowning and downbearing are included in the model. This study also considers the influence of geometric nonlinearities due to downbearing. The sensitivity analysis is performed using Spearman rank correlation and Sobol indices.
Using a Goal-Switching Selection Operator in Multi-Objective Genetic Algorithm Optimization Problems
Authors: Shaefer Daniel , Ferguson Scott
Published: February 2014

This paper demonstrates how solution quality for multiobjective optimization problems can be improved by altering the selection phase of a multiobjective genetic algorithm. Rather than the traditional roulette selection used in algorithms like NSGA-II, this paper adds a goal switching technique to the selection operator. Goal switching in this context represents the rotation of the selection operator among a problem’s various objective functions to increase search diversity. This rotation can be specified over a set period of generations, evaluations, CPU time, or other factors defined by the designer. This technique is tested using a set period of generations before switching occurs, with only one objective considered at a time. Two test cases are explored, the first as identified in the Congress on Evolutionary Computation (CEC) 2009 special session and the second a case study concerning the market-driven design of a MP3 player product line. These problems were chosen because the first test case’s Pareto frontier is continuous and concave while being relatively easy to find. The second Pareto frontier is more difficult to obtain and the problem’s design space is significantly more complex. Selection operators of roulette and roulette with goal switching were tested with 3 to 7 design variables for the CEC 09 problem, and 81 design variables for the MP3 player problem. Results show that goal switching improves the number of Pareto frontier points found and can also lead to improvements in hypervolume and/or mean time to convergence.
Power Harvesting Prediction of Piezoelectric Stack Actuator From a Shock Event
Authors: Lee Andrew J. , Wang Ya , Inman Daniel J.
Published: February 2014

In this study, the power harvesting performance of a piezoelectric (PZT) ceramic multilayer stack actuator under a shock event is theoretically and experimentally investigated. The model is derived from the constitutive - 33 mode equations under single degree of freedom (SDOF) assumptions, and then a correction factor is applied onto the resulting electromechanically coupled governing equations. These are represented in state space form and solved in the numerical computation software MATLAB. In order to achieve experimental validation, two test cases are compared to the model prediction when impulses of 20.8 mN·s and 1.70 mN·s are loaded on to the PZT stack actuator. The voltage and power output between the model and the test cases matched well. For the first case, the PZT stack actuator harvested 0.3321 μJ from the shock event while the model’s prediction was 0.3358 μJ, which results in a percent error of only 1.1%. In the second case, the PZT stack actuator harvested 34.64 nJ from the shock event while the model’s prediction was 35.80 nJ, which results in a percent error of 3.2%. This paper achieves its objective of deriving a model that can accurately predict the power harvested when an impulse load is applied onto a PZT stack actuator, and then validating this model with testing.
Computing Sensitivity Analysis of Vehicle Dynamics Based on Multibody Models
Authors: Zhu Yitao , Dopico Daniel , Sandu Corina , Sandu Adrian
Published: February 2014

Vehicle dynamics simulation based on multibody dynamics techniques has become a powerful tool for vehicle systems analysis and design. As this approach evolves, more and more details are required to increase the accuracy of the simulations, to improve their efficiency, or to provide more information that will allow various types of analyses. One very important direction is the optimization of multibody systems. Sensitivity analysis of the dynamics of multibody systems is essential for design optimization. Dynamic sensitivities, when needed, are often calculated by means of finite differences but, depending of the number of parameters involved, this procedure can be very demanding in terms of time and the accuracy obtained can be very poor in many cases if real perturbations are used. In this paper, several ways to perform the sensitivity analysis of multibody systems are explored including the direct sensitivity approaches and the adjoint sensitivity ones. Finally, the techniques proposed are applied to the dynamical optimization of a five bar mechanism and a vehicle suspension system.
Design and Development of the Single Motor Propelled Drive-Train (SiMPl-D)
Authors: Mandala Mahender , Pearlman Jonathan , Berner Olof , Kankipati Padmaja , Cooper Rory
Published: February 2014

Mobile robotic devices and other mobility related drive systems are often relegated to one of the two classes of devices available today: wheeled devices or tracked devices. Wheeled systems are more energy efficient and reliable than tracked systems, but existing designs have drawbacks related to rough-terrain driving and maneuvering in tight spaces.

In this paper we describe the design and development of a drive system named the Single Motor Propelled Drive-train (SiMPl-D), which can potentially improve maneuvering over rough terrain and in tight spaces compared to traditional wheeled robots. SiMPl-D has two prominent features: a single drive motor, which provides both propulsion and turning, and is suspended under the center of mass of the device on a swingarm, which is linked through a suspension system to caster wheels; and it has reconfigurable drive wheel, which changes the turning radius of the device.

Due to these features, SiMPl-D can traverse a wide range of terrain while remaining energy and cost efficient. SiMPl-D has been successfully used in an indoor/outdoor low-cost personal mobility device and is currently being implemented in other robotic mobility applications.
Effects of Feedback on Design Space Exploration
Authors: Foster Garrett , Denhart Jason , Ferguson Scott
Published: February 2014

The ultimate goal of this research is to provide computer based educational software that exposes engineering students to design tradeoffs early in their undergraduate experience. This paper investigates two feedback elements for their ability to enhance those students’ understanding of the tradeoffs inherent in a water rocket propulsion design problem: 1) a Latin hypercube sample that allows the student to select a starting point and 2) sensitivity values that displayed local gradient information. Assessments are made using data logged during the students’ interaction with the software and a series of quizzes performed throughout the study. The results indicate that the sensitivity information improves the students’ ability to locate designs with good performance, while the Latin hypercube adversely affects the students’ ability to visualize the objective space.
Using the Singularity Trace to Understand Linkage Motion Characteristics
Authors: Li Lin , Myszka David H. , Murray Andrew P. , Wampler Charles W.
Published: February 2014

This paper provides examples of a method used to analyze the motion characteristics of single-degree-of-freedom, closed-loop linkages under study a designated input angle and one or two design parameters. The method involves the construction of a singularity trace, which is a plot that reveals changes in the number of geometric inversions, singularities, and changes in the number of branches as a design parameter is varied. This paper applies the method to Watt II, Stephenson III and double butterfly linkages. For the latter two linkages, instances where the input angle is able to rotate more than one revolution between singularities have been identified. This characteristic demonstrates a net-zero, singularity free, activation sequence that places the mechanism into a different geometric inversion. Additional observations from the examples are given. Instances are shown where the singularity trace for the Watt II linkage includes multiple coincident projections of the singularity curve. Cases are shown where subtle changes to two design parameters of a Stephenson III linkage drastically alters the motion. Additionally, isolated critical points are found to exist for the double butterfly, where the linkage becomes a structure and looses the freedom to move.
Predictive Simulation of Human Ladder Climbing
Authors: Chung Hyun-Joon , Xiang Yujiang , Hariri Mahdiar , Bhatt Rajan , Arora Jasbir S. , Abdel-Malek Karim
Published: February 2014

An optimization formulation for human ladder climbing simulation is presented. The human model has 55 degrees of freedom — 49 revolute joints and 6 global translation & rotation joints. It is assumed that the ladder climbing motion is symmetric and periodic. The formulation starts with four contact points with both hands and feet. Then, hand and foot moves up and it ends with four contact points again. Design variables are the joint angle profiles and contact reaction forces. The objective function is combined with dynamic efforts and motion tracking. The dynamic efforts are joint torque square which is proportional to the mechanical energy. The motion tracking is the motion capture data tracking so that the motion follows the natural ladder climb motion as well. The dynamics results with joint torques and reaction forces are recovered and analyzed from the simulation.
A Miniature Wildlife Tracking UAV Payload System Using Acoustic Biotelemetry
Authors: Leonardo Miguel , Jensen Austin M. , Coopmans Calvin , McKee Mac , Chen YangQuan
Published: February 2014

Studying the biological processes of wildlife and how they react and prevail with human population growth and development has become very important to sustain species and prevent extinction. Wildlife tracking has become a very important tool in this matter by giving researchers an idea of animal territory and habitat. However, the process of finding the animal after it has been tagged can be very tedious and costly. To make this tracking process more efficient, researchers at Utah State University (USU) are developing a low cost RF telemetry system for wildlife tracking using an autonomous Unmanned Aerial Vehicle (UAV) for triangulation and geo-location of the target. The use of small unmanned aircraft systems (UAS) for wildlife tracking offer many advantages such as cost reduction, human effort reduction and data acquisition efficiency due to the usage flexibility offered by the system in comparison to conventional methods. This paper presents the design of this tracking system, and shows some experimental data.
Nanomechanical Property Analysis of Silica Aerogel
Authors: Pagano Claudia , Taylor Curtis R.
Published: February 2014

Aerogels (AGs) are open-cell nanofoams. AGs are lightweight and possess high thermal and acoustic insulation properties. Due to their ∼ 90% porosity, AGs are very brittle and fragile, which inhibits its use for load-bearing applications. For this reason an area of open research is the study and improvement of the mechanical properties of aerogels without altering their unique properties. Due to the extreme brittleness and low applied stress that AGs can support, direct mechanical measurements of AGs are challenging. To date very few experiments have been carried out to characterize the mechanical properties of aerogels; in particular at small contact dimensions and ultralow loads (nN-μN). In this paper, silica aerogel has been studied by nanoindentation using a diamond Berkovich indenter. We characterize the elasticity, stiffness, and hardness of the material as a function of contact depth (≤ 500 nm) at ultralow loads. The modulus and hardness are shown to change with depth with moduli and hardness ranging from 15–23 MPa and 3.5–6.8 MPa, respectively.
Shape Spirit: Deciphering Form Characteristics and Emotional Associations Through Geometric Abstraction
Authors: Orbay Gunay , Fu Luoting , Kara Levent Burak
Published: February 2014

Understanding and tailoring the visual elements of a developing product to evoke a desired emotional response and aesthetic perception is a key challenge in industrial design. To date, computational approaches to assist this process have either relied on stiff geometric representations, or focused on superficial features that exclude often elusive shape characteristics. In this work, we aim to study the relationship between product form and consumer emotions through a visual deconstruction and abstraction of existing final products. In particular, we attempt to answer three questions: (1) Do observers’ aesthetic judgments rely on the product as a whole, including fine geometric details, superficial surface features, and brand-revealing icons, or are large, prominent shape characteristics sufficient to make this determination? (2) Is it possible to isolate shape features that give rise to specific emotional responses? (3) Is there a relationship between consumers’ ability to recognize a brand and the emotional attributes they associate with that brand. At the heart of our investigation is a shape analysis method that produces a spectrum of abstractions for a given 3D computer model. This produces a hierarchical simplification of an end product, whereby consumer response to geometric elements can be statistically studied across different products, as well as across the different abstractions of one particular product. The results of our study show that emotional responses evoked by coarse product “impressions” are strongly correlated with those evoked by final production models. This, in turn, highlights the importance of early aesthetic assessment and exploration before committing to detail design efforts.
Impact of Gear Bias Control on Vehicle NVH
Authors: Sugyarto Eddy , Takahashi Yuki
Published: February 2014

This paper is based on Honda product development and maturation related to noise and vibration. During the development, it was discovered that the vibration level of the vehicle did not meet the desired level.

These studies are aimed to reduce the noise and vibration felt in vehicle by improving the powertrain as the main source of the vibration. During the investigation, it was discovered that manufacturing process change from tooth shaving to tooth honing could have significant impact on the final tooth profile that essentially impact the noise and vibration level of the vehicle.

The studies focus on bias control to improve the vibration level. This paper will show complete relationship between actual gear profile, vibration level of unit as powertrain, and finally airborne noise level of the complete vehicle as the final product. The studies resulted in shifting bias control target for the gear tooth profile, which translates to improved noise and vibration level in vehicle.
A Modified Discrete Empirical Interpolation Method for Reducing Non-Linear Structural Finite Element Models
Authors: Tiso Paolo , Dedden Rob , Rixen Daniel
Published: February 2014

Model Order Reduction (MOR) in nonlinear structural analysis problems in usually carried out by a Galerkin projection of the primary variables on a sensibly smaller space. However, the cost of computing the nonlinear terms is still of the order of the full system. The Discrete Empirical Interpolation Method (DEIM) is an effective algorithm to reduce the computational cost of the nonlinear terms of the discretized governing equations. However, its efficiency is diminished when applied to a Finite Element (FE) framework. We present here an alternative formulation of the DEIM that suits FE discretized problems and preserves the efficiency and the accuracy of the original DEIM method.
Analysis of a Low Effort Rectilinear Gait for a Snake-Inspired Robot
Authors: Hopkins James K. , Gupta Satyandra K.
Published: February 2014

In recent years, snake-inspired locomotion has garnered increasing interest in the bio-inspired robotics community. This positive trend is largely due to the unique and highly effective gaits utilized by snakes to traverse various terrains and obstacles. These gaits make use of a snake’s hyper-redundant body structure to adapt to the terrain and maneuver through tight spaces. Snake-inspired robots utilizing rectilinear motion, one of the primary gaits observed in natural snakes, have demonstrated favorable results on various terrains. However, previous variations of the rectilinear gait were inefficient in cyclic displacement. These gaits generated vertical waves traveling along the length of the robot. Generating these waves required significant joint energy for relatively small horizontal displacements. This paper presents analytical and experimental results for a rectilinear gait, which demonstrates significant linear displacement for relatively low joint effort. The low effort gait functions by propagating a wave through the length of the robot via expansions and contractions of the body segments, propelling the robot platform forward. The low effort rectilinear gait is demonstrated on a robot platform that incorporates high speed linear motion and variable traction through friction. We also report the results of a case study showcasing the practical benefits of the low effort gait.
Empirical Studies of Design Thinking: Past, Present, Future
Authors: Cagan Jonathan , Dinar Mahmoud , Shah Jami J. , Leifer Larry , Linsey Julie , Smith Steve , Vargas-Hernandez Noe
Published: February 2014

Empirical methods used for studying design thinking have included verbal protocols, case studies, and controlled experiments. Studies have looked at the role of design methods, strategies, tools, environment, experience, and group dynamics. Early empirical studies were casual and exploratory with loosely defined objectives and informal analysis methods. Current studies have become more formal, factor controlled, aiming at hypothesis testing, using statistical DOE and analysis methods such as ANOVA. Popular pursuits include comparison of experts and novices, identifying and overcoming fixation, role of analogies, effectiveness of ideation methods, and other various tools. A variety of data may be collected, related to both the process and the outcome (designs).There are still no standards for designing, collecting and analyzing data, partly due to the lack of cognitive models and theories of design thinking. Data analysis is tedious and the rate of discoveries has been slow. Future studies may need to develop computer based data collection and automated analyses, which may facilitate collection of massive amounts of data with the potential of rapid advancement of the rate of discoveries and development of cognitive models of design thinking.
Functional Modeling of Human Joints: A Feasibility Study for the Knee
Authors: Conconi Michele , Parenti Castelli Vincenzo
Published: February 2014

Biological tissues are plastic with respect to the mechanical environment to which they are exposed. This makes them able to modify their architecture and inner structure in order to respond to different loading conditions with the smallest biological effort (functional adaptation). As a result, tissues can optimally adapt their structures to the task they have to perform.

Based on these concepts, a kinetic model of the ankle joint has been recently developed. The tibio-talar relative motion was obtained by imposing the congruence maximization as a biological optimum throughout the entire flexion range.

The aim of this work is to investigate the applicability of the proposed approach to the knee and to evaluate the weight of the meniscal contribution to the global femoro-tibial congruence.
A Review of Transient Electrical Upsets in Induction Motors and Their Effects on Centrifugal Compressors
Authors: Moeller Michael , Srinivasan Anand
Published: February 2014

For several decades in the process industry, critical plant operations demanding continuous run time have used high speed turbocompressors, most commonly driven by induction motors. Transient disturbances, caused by grid and motor-terminal upsets, are common occurrences in three-phase induction motors. Such upsets can arise during start-up as well as steady state operating conditions, and can have an impact on the driven equipment. Common upset conditions include startup line bursts, voltage unbalances, two-phase & three-phase short circuits, and bus-transfers & reclosures. These transient upsets not only impact the motor, but also have a torsional influence on the motor-compressor drive-train. Understanding the significance of these upsets, and how it impacts the driven equipment is thus an important part of machinery design and the component selection process for centrifugal compressors. This paper presents a qualitative approach to analyzing these transient conditions arising from induction motors, and the resulting effects on driven equipment such as centrifugal compressors.

As the compression industry continues to develop into a globally integrated market, it becomes even more important to understand these effects; to ensure that a consistent global strategy exists to control these upsets and to mitigate some of the ill-effects resulting from torsional bursts on the drive train. A review of the current industry standards and mitigation techniques has also been presented.
A Frequency-Modulation Command-Shaping Strategy for Multi-Mode Systems
Authors: Masoud Ziyad N. , Alhazza Khaled A.
Published: February 2014

Single-mode shaped commands can be implemented for oscillations control of multi-mode systems provided that all frequencies of the system are odd-multiples of the shaped command frequency. This criterion is utilized in this work to develop a command shaping strategy for multi-mode systems. A frequency-modulation command shaper is derived based on the use of a single-mode command-shaping technique. The proposed strategy is based on deriving a closed-loop model of a multi-mode system with its modal frequencies modulated so that higher mode frequencies are odd-multiples of the first mode frequency. A single-mode double-step primary command-shaper with a design frequency equal to the first mode frequency of the closed-loop system is then used. The input command to the plant of the closed-loop system is used as shaped commands for the multi-mode system. Numerical simulations are used to demonstrate the performance of the proposed strategy along with experiments on scaled models of a triple, quadruple, and quintuple-pendulums.
New High Performance Gear Steels for Rotorcraft Transmission Applications (Ferrium® C61™ and Ferrium C64™)
Authors: Sebastian Jason , Grabowski Jeff , Snyder Dave
Published: February 2014

QuesTek Innovations LLC will present an overview of its Ferrium® C61™ and Ferrium C64™ high-performance gear steels. QuesTek designed, developed and implemented these two new steels using its Materials by Design® technology, an “Integrated Computational Materials Engineering” (ICME)-type approach. Both steels are commercially available (Ferrium C61 falls under Aerospace Materials Specification [AMS] number 6517 and Ferrium C64 falls under AMS 6509) and both can significantly reduce rotorcraft weight and manufacturing costs while increasing operational robustness (including gear steel oil-out/high temperature survivability). Ferrium C61 and C64 are new high strength, secondary hardening gear steels that offer different levels of case hardness. These highly-processable steels exhibit excellent hardenability, and were explicitly designed to leverage the advantages of high-temperature vacuum carburization. Ferrium C61 (AMS 6517) exhibits both excellent surface fatigue and core properties (225 ksi yield strength, 240 ksi ultimate tensile strength, 130 ksi•?in fracture toughness), and is a good candidate for integral gear/shaft applications where maximum torque transfer with minimum weight is tantamount. Ferrium C64 (AMS 6509) exhibits excellent surface hardness (62+ HRC after vacuum carburization), with the potential for significantly better surface fatigue performance as compared to incumbent gear steels such as AISI 9310 (AMS 6265) and Pyrowear® Alloy 53 (AMS 6308). The final tempering temperatures of both C61 and C64 (482–510°C) are 200–300°C higher than most incumbent gear steels, providing excellent scoring resistance and superior thermal stability in high-temperature environments and “oil-out” emergency conditions. Rotorcraft applications underway include an evaluation of C64 by Bell Helicopter under the U.S. Army Future Advanced Rotorcraft Drive Systems (FARDS) program, and of C61 for the forward rotorshaft of Boeing’s CH-47 Chinook under a U.S. Army Small Business Innovation Research (SBIR) Phase II project.
A Comparison of Surfacelet-Based Methods for Recognizing Linear Geometric Features in Material Microstructure
Authors: Jeong Namin , Rosen David W. , Wang Yan
Published: February 2014

Integration of material information and mechanical properties with geometry enables many product development activities, including design, analysis, and manufacturing. To integrate material information into CAD systems, geometric features of material microstructure must be recognized and represented, which is the focus of this paper. Linear microstructure features, such as fibers or grain boundaries, can be found computationally from microstructure images using surfacelet based methods, which include the Radon or Radon-like transform followed by a wavelet transform. By finding peaks in the transform results, linear features can be recognized and characterized by length, orientation, and position. The challenge is that often a feature will be imprecisely represented in the transformed parameter space. In this paper, we investigate several variations of the surfacelet based feature recognition methods, including masks, clustering methods, and whether to recognize features in the Radon or wavelet transform. These variations will be investigated to identify their strengths and limitations on a metal alloy and reinforced polymer microstructures.
SQP-Based Mobile Manipulator Motion Planning With Controlled Infeasibility for Physically Valid Task Failure
Authors: Joo Chang B. , Kim Joo H.
Published: February 2014

Since anticipating or recovering infeasibility in optimal motion planning is not always possible, infeasibilities occur frequently and are not completely avoidable. We introduce an enhanced sequential quadratic programming (SQP) based framework of controlled infeasibility for physically valid solutions, based on our previous study. A priority weight function is incorporated into an SQP algorithm combined with constraints and objective function normalization to ensure strict satisfaction of high-priority constraints. These are embedded in the SQP algorithm through its merit function and composite cost function, in which general nonlinear functions can be incorporated in a unified approach. Several simple mobile manipulator examples demonstrate the advantages of the proposed method.
Development of a Product Information Model to Support Replacement Analysis
Authors: Baysal Mehmet Murat , Roy Utpal
Published: February 2014

For sustainability of environment, legislations in EU, USA, Japan and Australia require manufacturers to take back their products at the End of Life (EOL) and recycle them. The concept of 6R (reduce, reuse, recycle, recover, redesign and remanufacture) is very important for this issue, while reuse has the highest energy and material recovery efficiency. In this study, an integrated product information model has been developed in UML to provide necessary information for any future decision making activities in the EOL stage, such as the replacement analysis of any used part or subassembly.

This product information model represents not only product structure but its function, behavior, and their associations in different abstract levels to support replacement analysis of an existing component with a new or a used component available to company. This representation schema provides necessary information for any future decision making activities in the EOL stage, such as the replacement or reuse of any part or subassembly. In an analysis of replacement for a faulty component with a used or new component, this model provides all of the associations of the existing artifact with other artifacts and the environment, not just functional and space requirements, and the relevant modification(s) of the associated objects has to be verified.
Evaluation of Auxiliary Device Efficiency in Heavy Vehicle Application
Authors: Sjostedt Carl-Johan , Wikander Jan , Flemmer Henrik
Published: February 2014

To investigate the energy consumption related to auxiliary devices, as a basis for optimizing the auxiliary systems’ layout and identifying potential for fuel consumption reduction, a study has been carried out at Scania CV AB. The following auxiliary devices have been investigated: Alternator, water pump, cooling fan, air compressor, air conditioning compressor, oil pump and power steering pump. Those auxiliary devices represent 5–7% of the total fuel consumption in long haulage truck applications, while for a city bus the figure could be as high as 50%. One of the challenges of evaluating the fuel consumption of auxiliary devices is the variance: it depends on many factors including road data, driver profile, ambient conditions (temperature, pressure, precipitation) and more. To investigate this variance, test data collected from the Scania test fleet has been analyzed. The data are used as input to a MATLAB/Simulink model of the auxiliary systems. This way, a large population of trucks has been investigated, for many driving cycles under realistic conditions. A general model for reducing fuel consumption for auxiliary systems has been developed.
An Agent-Based Method to Investigate Customers’ Preference in Product Lifecycle
Authors: Afshari Hamid , Peng Qingjin , Gu Peihua
Published: February 2014

Consumer requirements for products vary dynamically based on the change of technologies, social influence, individual taste, etc. A sustainable product should meet customer requirements in its lifecycle. Different methods and techniques have been proposed to find possible changes of product needs or customers’ preferences. This paper introduces an agent-based technique to address the change of product requirements. Major contribution of the proposed method is to embed customers’ preference in the analysis of product performance using agent interactions. Using the combination of Quality Function Deployment (QFD), agent-based modeling and data mining methods, customers’ preference trends related to elements and functions of product are simulated. The prediction period is flexible based on estimated product lifecycle. The proposed method is compared with other techniques in a case study.
Characterization of Thermoelectric Oxide Nanofibers Using MEMS Device
Authors: Xu Weihe , Zhang Guitao , Hadim Hamid , Shi Yong
Published: February 2014

Thermoelectric oxide nanofibers prepared by electrospinning was expected to have a significantly reduced thermal conductivity compared with their bulk forms. However, the measurement of the thermal conductivity of such a single nanofiber was very difficult because of sample preparation, sample loading and the lack of characterization tools. In this work, a technology that can be used to measure the thermal conductivity of a single nanofiber prepared by electrospinning was developed. A special Si template was designed to collect and transfer the thermoelectric nanofibers prepared by electrospinning. A microelectro-mechanical (MEMS) device was designed and fabricated to measure the thermal conductivity of a single nanofiber. The structure of the MEMS device was specially designed therefore a single nanofiber collected by the special Si template can be transferred onto the MEMS device. A La0.95Sr0.05CoO3 nanofiber with the diameter of 290 nm was prepared and characterized by this technology. The measured thermal conductivity of the nanofiber was 2.07 W/m•K, which is 30% lower than that of the bulk form La0.95Sr0.05CoO3 previously reported.