bluuebunny/crossref_metadata_2025 huggingface dataset:
Multi-Point Multi-Harmonic Collocation With Continuation to Compute Branches of Nonlinear Modes of Structural Systems
Authors: Kelly Sean J. , Allen Matthew S. , Ardeh Hamid
Published: January 2016

Fast numerical approaches have recently been proposed to compute the undamped nonlinear normal modes (NNMs) of discrete and structural systems, and these have enabled remarkable insights into the nonlinear behavior of more complicated systems than are tractable analytically. Ardeh et al. recently proposed the multi-point, multi-harmonic collocation (MMC) method, which finds a truncated harmonic description of a structure’s NNMs. The MMC algorithm resembles harmonic balance but doesn’t require any analytical pre-processing nor the computational expense of the alternating time-frequency method. In a previous work this method showed significantly faster performance than the shooting method and it also allows the possibility of truncating the description of the NNM to avoid having to compute every internal resonance. This work presents a pseudo-arc length continuation version of the MMC algorithm which can compute a branch of NNMs and compares its performance with the shooting/pseudo-arc length continuation algorithm presented by Peeters and Kerschen in 2009. The algorithms are compared for two systems, a two degree-of-freedom (DOF) spring-mass system and a 10-DOF model of a simply-supported beam.
Variance-Based Wheel/Rail Contact Sensitivity Analysis in Respect of Wheelset Dynamics
Authors: Bideleh Seyed Milad Mousavi , Berbyuk Viktor
Published: January 2016

To get a deep insight into bogie suspension design, it is important to identify those wheelset dynamics states and running conditions that can influence contact mechanics and wear, remarkably. In this regard, global sensitivity analysis of wheel/rail contact creepages, forces, and wear with respect to wheelset dynamics states, vehicle speed, and normal contact force is scrutinized. The Gaussian quadrature integrals together with multiplicative dimension reduction method (M-DRM) are employed to approximate the global sensitivity indices of wheel/rail contact mechanics. Using simulation results of a one car railway vehicle model, a feasible state vector is chosen as the cut center for sensitivity analysis of a single rigid wheelset with 6 degrees of freedom. The state vector, speed, and normal contact force are varied around the cut center according to a predefined set of independent and identically distributed random numbers. A computational model is developed to attain the contact point positions on wheel and rail as well as nonlinear creepages. The corresponding contact stimuli vector is obtained using FASTSIM algorithm and wear is modelled as the energy dissipation in the contact patch. The wheelset dynamics effects on wheel/rail contact mechanics are then explored. The results showed wear is mostly sensitive with respect to yaw motion and lateral speed of the wheelset. Such an analysis provides informative data that can be used in vibration control and suspension design in railway applications.
Attitude Adjustment of a Quadruped Robot in the Air
Authors: Zhou Wei , Chen Yinong , Ma Yijun , Pei Xu
Published: January 2016

When the moments of climbing robots, jumping robots, and gliding robots extend to the air, they should reorient themselves to minimize the damage during a fall. Based on imitating a falling cat, robot can reorientate about one axis without external force. In this paper, an extended attitude adjustment method for quadruped robots is presented to achieve three degrees of freedom attitude adjustment with the movement of four robotic limbs. A mathematical model of a falling robot is established based on the multi-rigid-body unrooted tree system. The response of the prototype’s azimuth to the input of the cylindrical hinges is analyzed. A 3D model prototype was designed in SolidWorks and simulation experiments were carried out in ADAMS. Prototype were manufactured with a 3D printer, to validate the attitude adjustment method. The simulation and experimental results showed that the main body of the prototype was able to rotate respectively 89 degrees in the X-axis, 89 degrees in Y-axis, and 49 degrees in Z-axis in a movement cycle of the robotic limbs.
A Closed-Form Lower Bound on the Allowable Motion for an Ellipsoidal Body and Environment
Authors: Ma Qianli , Chirikjian Gregory S.
Published: January 2016

In this paper, we present the closed-form representation of a subset of the allowable motion of an ellipse and an ellipsoid inside a simple elliptical and ellipsoidal environment based on the idea of kinematics of containment. Identifying an object’s free motion space, or equivalently the configuration space (C-space), is of great interest and practical use in computer-aided design and path planning problems. A special case exists when the object is constrained in an environment that is slightly larger than itself. We motivate our research by looking at the amount of free space in a cell for motion of the nucleus relative to the cell membrane. Therefore, we focus on elliptical and ellipsoidal shapes because of their similarity to the actual shape of a cell and its nucleus.

The subset of C-space defined by our closed-form representation is in spherical shape and the convexity of sphere makes it convenient to check whether two nodes in the C-space can be connected without collision. We derive the explicit expressions of the equation for both the single ellipse and single ellipsoid case. Existing methods are implemented and verified while a new method is proposed that shows better performance at enclosing a sub C-space with a larger volume.
Design and Fabrication of a Soft Robotic Direct Cardiac Compression Device
Authors: Roche Ellen T. , Horvath Markus A. , Alazmani Ali , Galloway Kevin C. , Vasilyev Nikolay V. , Mooney David J. , Pigula Frank A. , Walsh Conor J.
Published: January 2016

A direct cardiac compression (DCC) device is an active sleeve that is surgically placed around the heart to help the failing heart to pump without contacting blood. Soft robotic techniques enable fabrication of a conformable DCC device containing modular actuators oriented in a biomimetic manner that can restore the natural motion of the heart and provide tunable active assistance. In this paper we describe the fabrication of a DCC device; the optimization of pneumatic actuators, their integration into a matrix with a modulus in the range of cardiac tissue and methods to affix this device to the heart wall. Pneumatic air muscles (PAMs) were fabricated using a modified McKibben technique and four types of internal bladders; low durometer silicone tubes molded in-house, polyester terephthalate (PET) heat shrink tubing, nylon medical balloons and thermoplastic urethane (TPU) balloons thermally formed in-house. Balloons were bonded to air supply lines, placed inside a braided nylon mesh with a 6.35mm resting diameter and bonded at one end. When pressurized to 145kPa silicone tubes failed and PET, nylon and TPU actuators generated isometric axial forces of 14.28, 19.65 and 19.05N respectively, with axial contractions of 33.11, 28.69 and 37.54%. Circumferential actuators placed around the heart reduced the cross-sectional area by 33.34% and 50.63% for silicone and TPU actuators respectively. PAMs were integrated into a soft matrix in a biomimetic orientation using three techniques; casting, thermal forming and layering. Designs were compared on an in vitro cardiac simulator and generated a volumetric displacement of up to 96ml when actuated for 200ms at 1Hz. Layering produced the lowest profile device that successfully conformed to the heart and this design is currently undergoing in vivo testing.
Software Based Methods to Harden Embedded Software at Run-Time: A Survey
Authors: Kramer Michael , Horauer Martin
Published: January 2016

Embedded Systems software reliability is increasingly important, therefore methods to harden existing software are needed. In general, hardening software against various failures is a necessity in modern computer systems. A lot of work has been published regarding many possible ways to achieve this non-functional requirement. Relevant topics include, e.g., test procedures, recommended development flows, and hardware measures like watchdog timers. One of these methods seems very promising to be software implemented in modern embedded systems: Control Flow Checking by signatures. Various authors have shown the effectiveness and feasibility of Control Flow Checking (CFC) by signatures for personal computer software. For instance it has been shown for standard computer-systems, that CFC is capable of reducing undetected control flow errors by at least one magnitude.

This survey will focus on the applicability of such software hardening methods to embedded systems, while adhering mainly to software based approaches. Published methods will be summarized and compared. Furthermore methods to simplify derived control-flow graphs to essential states will be emphasized. Finally the possibility to apply run-time verification to the Control-flow Checking Software is considered.
A Gripper for Handling Large Leather Plies Stacked on Beams
Authors: Corinaldi David , Callegari Massimo , Palpacelli Matteo-Claudio , Palmieri Giacomo
Published: January 2016

The paper presents the preliminary design of a novel gripper able to grasp large non-rigid materials that has been conceived to face the challenge of automatic handling tasks in the leather industry. The design has been driven by the requirements to limit production costs and the complexity of the grasping device. A statistical analysis of the different templates sizes has allowed to identify a fixed configuration of the gripping points able to properly pick all the sheets within a great confidence interval. According to the varying shape of the leather templates themselves, that is due to their stacking in plies on the beam, the trajectory of the gripping points has been studied and arranged. Due to the irregular shape of the large sheets that are handled, the edges of the non-rigid materials out of the gripping area might flutter during the transferring phase: a four-bar linkage has been specifically designed, so that the motion of its end-effector prevents unwanted leather creases.
Maneuvering Car Tracking Using the Interacting Multiple Model and the Dynamic 2nd-Order SVSF Method
Authors: Attari Mina , Afshari Hamed Hossein , Habibi Saeid
Published: January 2016

Car tracking algorithms have recently found a major role in intelligent automotive applications. They are mainly based on the state estimation techniques to solve the maneuvering car tracking problems. The dynamic 2nd-order SVSF method is a novel robust state estimation method that is based on the variable structure control theory. It benefits from the accuracy, robustness, and chattering suppression properties of second-order sliding mode systems for robust state estimation. The main contribution of this paper is to present and implement a new tracking strategy that is a combination of the dynamic 2nd-order SVSF with the IMM filter. It benefits from the robust performance of the dynamic 2nd-order SVSF and the switching property of the IMM filter. This strategy is simulated and examined under several car driving patterns and experimental position data that are captured by a GPS device. The robustness and efficiency of this strategy is then compared with the Kalman filter-based counterparts.
Bridging Learning Gap Through Peer-to-Peer Information Exchange in a Flat Environment
Authors: Ramachandran Madhumitha , Siddique Zahed , Kremer Gül E. Okudan , Akasheh Firas
Published: January 2016

In this paper, we present a technology assisted flat learning environment, Teaching to Learn (TeatoL), where all participants have dual roles as students and instructors. The main objective of this work is to investigate how peer-to-peer information exchange aids in bridging knowledge gap in a flat-learning environment. We present our TeatoL implementation that was developed to enhance ill-structured problem solving skill along with its assessment. The participants in the learning environment were given an open design problem related to sheet metal forming. A short lecture about 35 minutes (Phase 0) was given and then student teams were asked to make an instructional video (Phase I) describing their approach for solving the open-ended problem. The videos were viewed by peers, using their computers and mobile devices. The students then critiqued and provided feedback on the posted videos (Phase II). The final step of the process had students write short reports on their problem solving approach (Phase III) that was modified based on peer-to-peer interactions. Student learning in all three phases was assessed to understand the effects of different modes of learning in TeatoL. Our findings indicate that TeatoL is an effective flat online learning environment. Correlation analysis suggests that learning gains are dependent on the level of knowledge on the topic for the learning community (class) and the number of meaningful comments provided by peers. The findings from this work can be utilized to develop technology based online peer learning environments to improve learning outcomes through active collaborative learning. Such an environment can be particularly useful for open course delivery.
The Development of a Human Gait Model With Predictive Capability and the Simulation of Able-Bodied Gait
Authors: Sun Jinming , Wu Shaoli , Voglewede Philip A.
Published: January 2016

The development of current prostheses and orthoses typically follows a trial and error approach where the devices are designed based on experience, tried on human subjects and then redesigned iteratively. This design approach is costly, risky and time consuming. A predictive human gait model is desired such that prostheses can be virtually tested so that their performance can be predicted qualitatively, the cost can be reduced, and the risks can be minimized. The development of such a model is explained in this paper. The developed model includes two parts: a plant model which represents the forward dynamics of human gait and a controller which represents the central nervous system (CNS). The development of the plant model is explained in a different paper. This paper focuses on the control algorithm development and able-bodied gait simulation. The controller proposed in this paper utilizes model predictive control (MPC). MPC uses an internal model to predict the output in advance, compare the predicted output to the reference, and optimize control input so that the error between them is minimal. The developed predictive human gait model was validated by simulating able-bodied human gait. The simulation results showed that the controller is able to simulate the kinematic output close to experimental data.
Discovery and Evaluation of Design Methods in Practice: An Empirical Study
Authors: Gericke Kilian , Roschuni Celeste , Kramer Julia
Published: January 2016

Web platforms and literature on design methods allow users to search for existing methods based on the method’s name and stage of use. Little support is provided to assess whether a method is appropriate for the task at hand and the context where the method will be applied.

In this explorative study, patterns in searching, selecting, assessing and exchanging experiences with peers in professional practice were analyzed across a range of disciplines. This work reports on our findings from interviews conducted with practicing engineers and designers.

Several similarities in the way practitioners find, select and assess new methods were found and interesting differences were identified for the practices in exchanging experiences with peers.

In this work, we present the findings of our interview study along with directions for future work to better understand design processes in professional practice.
Singularity Traces of Planar Linkages That Include Prismatic and Revolute Joints
Authors: Almestiri Saleh M. , Myszka David H. , Murray Andrew P. , Wampler Charles W.
Published: January 2016

This paper presents a general method to construct a singularity trace for single degree-of-freedom, closed-loop linkages that include prismatic, in addition to, revolute joints. The singularity trace has been introduced in the literature as a plot that reveals the gross motion characteristics of a linkage relative to a designated input joint and design parameter. Previously, singularity traces were restricted to mechanisms composed of only rigid bodies and revolute joints. The motion characteristics identified on the plot include changes in the number of solutions to the forward kinematic position analysis (geometric inversions), singularities, and changes in the number of branches. To illustrate the adaptation of the general method to include prismatic joints, basic slider-crank and inverted slider-crank linkages are explored. Singularity traces are then constructed for more complex Assur IV/3 linkages containing multiple prismatic joints. These Assur linkages are of interest as they form an architecture that is commonly used for mechanisms capable of approximating a shape change defined by a general set of closed curves.
Torsion Based Universal MEMS Logic Device
Authors: Ilyas Saad , Arevalo Arpys , Byas Ernesto , Foulds Ian G. , Younis Muhammad I.
Published: January 2016

In this work we demonstrate torsion based complementary MEMS logic device, which is capable, for the first time, of performing INVERTER, AND, NAND, NOR, and OR gates using one physical structure within an operating range of 0–10 volts. It can also perform XOR and XNOR with one access inverter using the same structure with different electrical interconnects. The paper presents modeling, fabrication and experimental calculations of various performance features of the device including lifetime, power consumption and resonance frequency. The fabricated device is 535 μm by 150 μm with a gap of 1.92 μm and a resonant frequency of 6.51 kHz. The device is capable of performing the switching operation with a frequency of 1 kHz.
Discrete-Event Simulation Software for Modeling Flexibility-Driven Manufacturing Processes
Authors: Galaske Nadia , Tantik Erdal , Anderl Reiner
Published: January 2016

In times of globalized markets and rapidly advancing technologies, companies are demanded to produce highly individualized products in shorter life cycles. This requires a certain flexibility in production processes, which, in turn, leads to a higher process complexity. In order to face these challenges, companies need to rely increasingly on the application of software tools for modeling and simulation of production systems.

One of the most commonly used tools in the field of digital production planning and control is the discrete-event simulation (DES). A discrete-event simulation software allows production planners to create digital models of production systems and simulate process and material flows. It can be used not only to improve the design of production systems in the early stage of planning, but also to analyze changes in the system’s behavior during operative processes.

In this paper, an event-based modeling and simulation software for flexibility-driven manufacturing processes in value-added process chains is developed. The software presented in this paper is aimed particularly at small and medium enterprises (SMEs) with low degree of automation and high product variety. The goal of this approach is to enable the modeling and simulation of manufacturing systems where the required manufacturing operations depend on production workers and vary with each production order. Using the approach described in this paper, a high variety of manufacturing process sequences in a flexible manufacturing system with different layouts, where material flows, worker paths, and part routings are not determined in fixed order, can be modeled, analyzed, and optimized.
Gesture Based Control of a Simulated Robot Manipulator
Authors: Dhami Sukhdeep S. , Sharma Ashutosh , Kumar Rohit , Kalra Parveen
Published: January 2016

The number of industrial and household robots is fast increasing. A simpler human-robot interaction is preferred in household robotic applications as well as in hazardous environments. Gesture based control of robots is a step in this direction. In this work, a virtual model of a 3-DOF robotic manipulator is developed using V-Realm Builder in MATLAB and the mathematical models of forward and inverse kinematics of the manipulator are coded in MATLAB/Simulink software. Human hand gestures are captured using a smartphone with accelerometer and orientation sensors. A wireless interface is provided for transferring smartphone sensory data to a laptop running MATLAB/Simulink software. The hand gestures are used as reference signal for moving the wrist of the robot. A user interface shows the instantaneous joint angles of robot manipulator and spatial coordinates of robot wrist. This simple yet effective tool aids in learning a number of aspects of robotics and mechatronics. The animated graphical model of the manipulator provides a better understanding of forward and inverse kinematics of robot manipulator. The robot control using hand gestures generates curiosity in student about interfacing of hardware with computer. It may also stimulate new ideas in students to develop virtual learning tools.
Design Optimization and Challenges of Large Folding Origami Structures
Authors: Fuchi Kazuko , Buskohl Philip R. , Bazzan Giorgio , Durstock Michael F. , Reich Gregory W. , Vaia Richard A. , Joo James J.
Published: January 2016

Reconfigurable structures based on origami design are useful for multi-functional applications, such as deployable shelters, solar array packaging, and tunable antennas. Origami provides a framework to decompose a complex 2D to 3D transformation into a series of folding operations about predetermined fold lines. Recent optimization toolsets have begun to enable a systematic search of the design space to not only optimize geometry, but mechanical performance criteria as well. However, selecting optimum fold patterns for large folding operations is challenging as geometric nonlinearity influences fold choice throughout the evolution. The present work investigates strategies for design optimization to incorporate the current and future configurations of the structure in the performance evaluation. An optimization method, combined with finite element analysis, is used to distribute mechanical properties within an initially flat structure to determine optimal crease patterns to achieve desired motions. Out-of-plane and twist displacement objectives are used in three examples. The influence of load increment and geometric nonlinearity on the choice of crease patterns is studied and appropriate optimization strategies are discussed.
Comparison of Simulations and Experiments of Loaded Spiral Bevel Gears Behavior
Authors: Teixeira Alves Joël , de Vaujany J. P. , Guingand M.
Published: January 2016

The design of spiral bevel gears is still very complex because tooth geometry and thus kinematics performance depend on the manufacturing process of this type of gear. The cutting process is dominated by two major manufacturers: Gleason and Klingelnberg. The shape of the teeth surfaces are governed by a large number of programmed machine settings, so they cannot be optimized intuitively. Due to the progress made during the last decade by CNC machines and CAM (Computer Aided Manufacturing) softwares, it is now possible to manufacture spiral bevel gears with quite good quality on a 5-axis milling machine.

In a previous study, the authors presented a numerical model for calculating the quasi-static load sharing of spiral bevel gears. Two kinds of geometries were developed: a simplified Gleason type, and a geometry based on classical spherical involutes combined with a logarithmic spiral. After being generated using a CAD (Computer-Aided Design) software, these two geometries were manufactured with a 5-axis milling machine controlled by CAM software. A metrological study showed that manufacturing by a 5-axis milling machine can be an alternative to conventional cutting methods.

The aim of the present paper is to validate the numerical model. To reach this goal, a test bench was designed to measure the loaded transmission error and visualize the contact patterns. The test bench is integrated inside a numerical 3-axis milling machine: the pinion is mounted on the spindle, while the base of the bench is clamped on its plate. Thus assembly errors can be imposed easily and accurately. Measured and simulated transmission errors are then compared for different axis misalignments cases.
Automated Cell Segmentation Method for Extracting Cell Information From Phase Contrast Microscopy of a Microfluidic Device
Authors: Khabiry Masoud , Jalili Nader
Published: January 2016

Technological advancement in cell and microscopy imaging generate a high demand for complex image analysis techniques. Image processing techniques are powerful tools to assess the images and extract information for quantization and evaluation of regions. It is crucial to develop advanced automatic cell segmentation methods with capability to analyze image data with high level of accuracy. In this paper, a quantitative technique is developed to count the number of cells from phase contrast microscopy. The technique selects region of interests (ROI) in the cell images and it measures the cell locations within ROI in a specific microfluidic device. The cell location is an important factor which will affect the flow pattern in the microfluidic device and consequently induced shear stresses.
Development of Graphical User Interfaces to Improve Human Design Proficiency for Complex Multi-Level Biosystems
Authors: Egan Paul F. , Schunn Christian , Cagan Jonathan , LeDuc Philip R.
Published: January 2016

Complex systems are challenging to design, particularly because of multi-level organizations that lead to non-obvious relationships among design components. One aspect of that challenge is how to effectively present complex information to the user for systems with multiple levels of organization. Two contrasting design graphical user interfaces (GUIs) were developed to aid multi-level biosystem design: a GUI with feedback via performance charts that emphasized learning of parametric relationships, and a GUI with feedback via agent-based animations that emphasized learning of inter-level causalities. The effectiveness of these interfaces is compared through assessing the design proficiency of human users for optimization design tasks. Results from user interactions with the interfaces demonstrated that users with both interfaces improved on pre-/post-learning design tasks, and users that demonstrated an understanding of inter-level causal relationships had greater improvement. However, only users with the animations interface tended to learn inter-level causal relationships. All users were then presented contrasting animations of systems with opposing emergent system behaviors, resulting in many more participants demonstrating an understanding of inter-level causal behaviors. These findings reveal the usefulness of interactive software tools for supporting engineers in overcoming challenges of complex systems design. Particularly, that successful design of complex systems requires unique reasoning skills that are informed by knowing how system components relate across levels, and specialized interfaces with animations provide information necessary for the learning these relationships.
Mathematical Model of Human Operator Using Fractional Calculus for Human-in-the-Loop Control
Authors: Huang Jiacai , Chen YangQuan , Li Zhuo
Published: January 2016

Mathematical models of human operator play a very important role in the Human-in-the-Loop manual control system. For several decades, modeling human operator’s dynamic has been an active research area. The traditional classical human operator models are usually developed using the Quasi-linear transfer function method, the optimal control theory method, and so on. The human operator models established by the above methods have deficiencies such as complicated and over parameterized, even for basic control elements. In this paper, based on the characteristics of human brain and behaviour, two kinds of fractional order mathematical models for describing human operator behavior are proposed. Through validation and comparison by the actual data, the best_fit model with smallest root mean squared error (RMSE) is obtained, which has simple structure with only few parameters, and each parameter has definite physical meaning.
Rapid Co-Design of Electro-Mechanical Specifications for Robotic Systems
Authors: Bezzo Nicola , Gebhard Peter , Lee Insup , Piccoli Matthew , Kumar Vijay , Yim Mark
Published: January 2016

Recent advances in design, fabrication, and programming technologies enable the rapid digital manufacturing of functional robotic systems. Novices can quickly fabricate mechanical frames thanks to 3D printers and cut-and-fold techniques and quickly program the control behavior of a robot using modern software environments. However, there is still not a systematic way to design custom printed circuit boards (PCB). In this work, we propose a hierarchical approach that allows casual users to quickly and easily create PCBs. A drag-and-drop graphical interface allows users to intuitively assemble PCBs from a library of predesigned, parameterized components, and a script-based infrastructure automatically composes all of the electronic systems based on user inputs. The final output is a fabrication-ready electronic design. Within this framework, we also propose a verification analysis that allows the user to quickly check that the developed design conforms to electrical constraints like voltage, current, and power limitations. Finally, we validate the proposed co-design environment with experimental results through the realization of a teleoperated segway robot.
Skateboard: A Human Controlled Non-Holonomic System
Authors: Varszegi Balazs , Takacs Denes , Stepan Gabor
Published: January 2016

A simple mechanical model of the skateboard-skater system is analyzed, in which a linear PD controller with delay is included to mimic the effect of human control. The equations of motion of the non-holonomic system are derived with the help of the Gibbs-Appell method. The linear stability analysis of rectilinear motion is carried out analytically using the D-subdivision method. It is shown how the control gains have to be varied with respect to the speed of the skateboard in order to stabilize the uniform motion. The critical reflex delay of the skater is determined as a function of the speed and the fore-aft location of the skater on the board. Based on these, an explanation is given for the well-known instability of the skateboard-skater system at high speed.
Shape-Morphing Space Frame (SMSF) Using Linear Bistable Elements
Authors: Alqasimi Ahmad , Lusk Craig
Published: January 2016

This paper presents a new concept: a Shape-Morphing Space Frame (SMSF), which is a novel application utilizing the Linear Bistable Compliant Crank-Slider Mechanism (LBCCSM). The frame’s initial shape is constructed from a single-layer grid of flexures, rigid links and LBCCSMs. The grid is bent into the space frame’s initial cylindrical shape, which can morph because of the inclusion of LBCCSMs in its structure. The design parameters consist of the frame’s initial height, its tessellation pattern (including bistable elements’ placement), its initial diameter, and the final desired shape. The method used in placing the bistable elements is a novel contribution to this work as it considers the principle stress trajectories. This paper will present two different examples of Shape-Morphing Space Frames, each starting from a cylindrical-shell space frame and morphing, one to a hyperbolic-shell space frame and the other to a spherical-shell space frame, both morphing by applying moments, which shear the cylindrical shell, and forces, which change the cylinder’s radius using Poisson’s effect.
Automatic Extraction of Function Knowledge From Text
Authors: Cheong Hyunmin , Li Wei , Cheung Adrian , Nogueira Andy , Iorio Francesco
Published: January 2016

This paper presents a method to automatically extract function knowledge from natural language text. Our method uses syntactic rules to extract subject-verb-object triplets from parsed text. We then leverage the Functional Basis taxonomy, WordNet, and word2vec to classify the triplets as artifact-function-energy flow knowledge. For evaluation, we compare the function definitions associated with 30 most frequent artifacts compiled in a human-constructed knowledge base, Oregon State University’s Design Repository (DR), to those extracted using our method from 4953 Wikipedia pages classified under the category “Machines”. Our method found function definitions for 66% of the test artifacts. For those artifacts found, our method identified 50% of the function definitions compiled in DR. In addition, 75% of the most frequent function definitions found by our method were also defined in DR. The results demonstrate the promising potential of our method in automatic extraction of function knowledge.
Soft Pressure Sensing Sleeve for Direct Cardiac Compression Device
Authors: Horvath Markus A. , Roche Ellen T. , Vogt Daniel M. , Mooney David J. , Pigula Frank A. , Walsh Conor J.
Published: January 2016

A direct cardiac compression (DCC) device is a non-blood contacting sleeve placed around the failing heart to actively assist blood pumping function. For design optimization of a DCC device, it is necessary to monitor the surface pressure exerted on the heart surface at multiple points during active assist, and to correlate this with device performance and cardiac output. In this paper, we present the design, fabrication and characterization of a soft, elastic, conformable pressure sensing sleeve that is placed at the heart/device interface to monitor device performance without affecting device function. This sleeve enables identification of optimal pre-tensioning, positioning and user-controlled parameters of the DCC device. Individual sensors (8×8×3 mm) were fabricated using a surface mount device (SMD) barometer on a custom double-sided flexible printed circuit board and casting the assembly in urethane rubber. A typical sensor has a dynamic range of 2.5 kPa to 50 kPa with a sensitivity of 11.3 counts per kPa. An array of up to 24 sensors was integrated into a flexible, stretchable circuit embedded in a thin (500 micron) silicone sheet using a multi-step layering fabrication process. Continuous magnet wires were wrapped around an alignment fixture, soldered to individual sensors in place and the entire circuit was transfer printed on to a silicone sheet. This assembly allows stretch corresponding to the fractional shortening of the heart muscles (up to 50%). The sleeve successfully measured static and dynamic pressures with a mechanical tensile tester and did not affect DCC device performance. Preliminary results demonstrated that the sleeve is robust enough to withstand >10000 cycles, compression forces from the DCC device and can achieve sensing range and repeatability suitable for procedural pressure monitoring for a DCC device. In addition to allowing performance measurements for iterating DCC device designs, the sensing sleeve can enable increased understanding of the response of the cardiovascular system to compressive assistance.
Inertia Properties and Representations in Mechanical Systems
Authors: Kövecses József , Kovács László L.
Published: January 2016

In Mechanics the core issue is the representation of forces. The concept of inertia is central in such definition. In finite degree-of-freedom dynamics models of a mechanical system inertia is generally represented based on the gradients of the kinetic energy function in terms of the selected generalized velocities. This selection of variables gives the parameterization of the system and allows one to gain insight into the nature of the behaviour and functioning of the system. A certain operation or interaction in a system can be characterized by selecting the proper parameterization. This also gives rise to the possibility to define effective inertia concepts that are particularly important to understand a function or an operation within a system. In this paper we present novel forms and concepts of effective inertia.
Simulating Variability of Rework Cost and Market Performance Estimates in Product Redesign
Authors: Von Hagel Kayla A. , Ferguson Scott M.
Published: January 2016

When considering the redesign of an existing product, designers must consider possible engineering and marketing ramifications. Ideal changes capture a large portion of the market and have a low risk of change propagation that results in reduced cost to the manufacturer. Engineering change tools such as the Change Prediction Method and market research models such as Hierarchical Bayes Mixed Logit allow designers to estimate the cost of the redesign process and market shares of preference. Variability in the inputs of the Change Prediction Method (impact and likelihood values) results in a range of redesign cost values. Assumptions regarding model form and the randomness used in model fitting also lead to variations when estimating market performance. When the variability associated with these techniques is considered, focus should shift from a point-estimate to a region-estimate. This paper explores the region-estimate produced for proposed redesigns when considering rework cost and market share of preference.
Failure Identification for Mission Analysis for Complex Systems
Authors: DeStefano Charlie , Jensen David
Published: January 2016

This paper presents a new method for complex system failure analysis that provides both an overall failure analysis on a system’s functionality as well as a mission-based failure analysis. The Failure Identification for Complex Mission Analysis (FICMA) method presented here uses physics-based governing equations to identify the system’s overall behavior during both nominal and faulty conditions. The FICMA method is unique in that it first identifies a specific failure, or combination of failures, within a system and determines how each failure scenario will affect the system’s overall functional capabilities. Then, FICMA uses this failure information to assess and optimize various mission plans that the system may be asked to perform. The FICMA method is designed to identify all potential functional failures of a given system, and then, depending on the types of failures that have occurred, to identify the optimal functional approach needed to successfully complete its current mission. First, the FICMA method employs MATLAB/Simulink software along with multiple unique metrics to simulate various potential failure scenarios. Then, based on how these failure scenarios affect the functionality of the system components, the mission plans are automatically optimized. This optimization is based on finding the mission plan that experiences the fewest total effects from a given failure scenario, i.e. the most robust mission plans. Also, by using the FICMA method, each component of a system can be simulated anywhere from 0–100% of its original functionality without the specific failure mechanisms being required, which allows for this method to be implemented early in the design process while still providing valuable and unique failure information. To demonstrate this new method, a theoretical case study of a 3-linkage robot arm was chosen. Through simulations of multiple failure scenarios and mission plans, the FICMA method’s unique assessment and optimization techniques will demonstrate how to determine the optimal plan for completing a mission after a failure scenario has occurred.
Exploring the Relationship Between Excess and System Evolutions Using a Stress-Test
Authors: Cansler Ethan Z. , Ferguson Scott M. , Mattson Christopher A.
Published: January 2016

Engineers understand that attaining a full service life can add value to an engineered system. Ensuring that this is possible requires that excess be embedded within the design to enable system evolution when new or changed requirements are placed on it during the service phase. However, since future needs are by definition unknown, knowing with certainty which excesses to embed is impossible. To address that challenge, this paper draws on an excess mapping method developed in previous work that demonstrated how to map component relationships based on excess interactions. This method is now used in a stress test approach to explore how a system design is affected when faced with various possible evolution scenarios. This study has two results: first, a judgment of whether the current system design possesses sufficient excess for it to respond to future needs. Second, quantitative estimates of excesses to add if the current design excess is judged to be insufficient. A demonstrative example is presented using a dart gun, which determines that the system as designed is likely adequate for a variety of possible future needs.
Considering Different Motivations in Design for Consumer-Behavior Change
Authors: Srivastava Jayesh , Shu L. H.
Published: January 2016

Much existing work aims to understand how to change human behavior through product-design interventions. Given the diversity of individuals and their motivations, solutions that address different motives are surprisingly rare. We aim to develop and validate a framework that clearly identifies and targets different types of behavioral motives in users. We present a behavior model comprising egoistic, sociocultural and altruistic motives, and apply the model to sustainable behavior. We confirmed the explanatory power of the behavior model by categorizing user comments about an international environmental agreement from multiple news sources.

We next developed concepts, each intended to target a single motive type, and elicited evaluations from online respondents who self-assessed their motivation type after evaluating the concepts. We present and discuss correlation results between motive types and preference for products that target these types for two iterations of the experiment. Deviations from our expected results are mainly due to unexpected perceptions, both positive and negative, of our concepts. Despite this, the main value of this work lies in the explicit consideration of a manageable number of different types of motives. A proposed design tool incorporates the three types of motives from the model with the different levels of persuasion others have proposed to change user behavior.
On the Effect of Lightweight Gear Blank Topology on Transmission Dynamics
Authors: Toso Alessandro , van Wermeskerken Freek , Cappellini Niccolò , Heirman Gert
Published: January 2016

This paper describes the effect of gear blank topology on the gear meshing stiffness and consequently on the dynamic loads in gear transmissions. The characteristics of these forces, especially their frequency content, will determine the NVH and durability properties of the entire transmission. To assess the level of induced vibrations and the acoustic radiation from the transmission housing, it is important to properly model the excitation mechanism originating from the meshing gears. Several authors have proposed semi-empirical formulas [1–3] to compute the meshing stiffness, however most of them assume a solid gear blank and provide some correction factors in case of thin rims and webs [4]. Nevertheless current trends in transmission design also include extreme measures to reduce the gear weight that have an influence of the meshing stiffness that cannot be fully captured with the abovementioned methodologies. This papers proposes a methodology to model this phenomenon and shows by means of a numerical example that lightweight flexible gear blanks have a non-negligible effect on meshing forces.
A Cross-Sectional and Longitudinal Examination of the Development of Innovation Capability in Undergraduate Engineering Students
Authors: Kershaw Trina C. , Peterson Rebecca L. , McCarthy Molly A. , Young Adam P. , Seepersad Carolyn Conner , Williams Paul T. , Hölttä-Otto Katja , Bhowmick Sankha
Published: January 2016

Multiple research studies have examined the role of the undergraduate engineering curriculum on students’ innovation capabilities. The majority of these studies have used cross-sectional samples to compare students at the beginning and end of their college careers, and most results have shown that seniors outperform freshmen. In the following paper, we use a combination of cross-sectional and longitudinal comparisons to uncover when innovation capabilities grow. Over a two-year period, undergraduate engineering majors at different points in their college careers completed concept generation tasks. Their resulting concepts were scored for originality. While no difference was found from freshman to senior year using a cross-sectional comparison, a significant increase in originality was found between separate senior groups at the beginning and end of a capstone course. The difference between the senior groups occurred despite no difference between these students in academic performance or engineering design self-efficacy. In addition, a significant increase in originality was found from junior to senior year using a longitudinal analysis. This increase in originality occurred without corresponding changes in academic performance or engineering design self-efficacy. These results are discussed in relation to prior research regarding the interplay between curricular and individual difference factors in the development of students’ innovation capabilities.
An Investigation of Design Requirement Volatility, Risk and Priority in Early Stage Design Projects
Authors: Bao Qifang , Morocz Francisco , Ferik Sami El , Shaukat Mian Mobeen , Yang Maria C.
Published: January 2016

In new product development, design requirements are a formalization of a product vision and can evolve substantially in the early stages of product design. This paper describes an empirical study of the relationships among design requirements volatility, risk, prioritization and the quality of design outcome in the context of a graduate level product development course for mid-career professionals. Among other findings, a pattern of decreasing risk of a design requirement, especially the risk of high priority requirements, was found to be a key predictor of success. The findings suggest the importance of managing design requirement risk in early stage design and the potential benefit of using risk and priority level of design requirements to monitor design project health.
A Validation Study of Disability Simulation Suit Usage as a Proxy for Customer Need Statements From Persons With Disabilities
Authors: Armstrong Jessica , Stone Rob , Immel Sebastian , Hunter-Zaworski Katharine
Published: January 2016

Current product design methodologies do not typically address the creation of inclusive products (products that meet the needs of persons with and without disabilities). In this paper, empathic design principles and modular product design strategies are explored as part of a novel approach to inclusive design. The use of disability simulation as a data collection methodology both increases the safety and ease by which customer needs can be gathered and gives designers an empathic design experience with the products they develop. A disability simulation suit is designed to support empathic gathering of customer needs. The suit is subjected to validation trials to determine how accurately it mimics the physical and perceptual behaviors of persons with disabilities in users of the suit. Initial results show that the disability simulation suit provides a valid empathic design experience that yields similar customer needs and reduced dexterity as persons with disabilities.