bluuebunny/crossref_metadata_2025 huggingface dataset:
Geometric Descriptor-Based Local Contour Point Set Matching for Cross-Section Profile Measurement of Automotive Sealing Strips
Authors: Li Jianhua , Du Zhengchun , Zhang Ying , Wang Yan
Published: January 2016

In vision-based measurement, there is a lack of effective methods for local contour matching of flexible automotive rubber product contour due to its flexibility. In this paper, we propose a novel local contour point set matching method based on a geometric descriptor. A geometric descriptor of a local point set includes shape properties of the point set and position information. In local matching process, the geometric descriptor of a standard point set is extracted and a tolerable geometric descriptor for a desired point set is also generated through adding more factors to the standard descriptor. According to the generated tolerable descriptor, an angle similarity optimization searching is used to find the best matched local point set within a constrained position limit. This method has been implemented in a sealing strip cross-section measurement system, and several cross-section profiles of automotive sealing strips have been tested. The results show the stability and effectiveness of the proposed method and this method can lead to an automated measurement for flexible products.
Assessing and Generating Modules for Product Recovery
Authors: Kim Samyeon , Moon Seung Ki
Published: January 2016

As technology pushes customers to buy new released products, especially mobile phone, high product replacement from the customers plays a role in increasing production rate for new products and rate of abandoned products. It accelerates environmental degradation like natural resource usage for the new products and pollutions generated by disposing the abandoned products. In this respect, product recovery is needed to reduce landfill rates, and resource usages, and prolong product lifecycle. Modular drivers such as interface design, material type, and components’ lifespan are applied to design modules for product recovery. The objective of this research is to support designers to assess initial modules and then reorganize modules for product recovery. First, according to conventional modular product design, the initial modules are generated. Then, since it is difficult to estimate how much the modules have negative effects on environment, the environmental impacts of a product are assessed by Eco-Indicator 99 based on used materials. Also, the complexity of the interface design is measured to understand how the modules are easily disassembled for upgrading and maintaining end-of-life products by using weighted-modular complexity score (wMCS). After assessing the product based on the Eco-Indicator 99 and wMCS, we apply new design guidelines to improve sustainability of a product in the end of life stage. Consequently, we compare the extent to design for sustainability before and after redesigning a product based on the design guideline. To demonstrate the effectiveness of the modular product design, we carry out a case study with a coffee maker.
Combinatorial Method for Checking Stability in Tensegrity Structures
Authors: Cahan Daniel , Shai Offer
Published: January 2016

Tensegrity structures have a great value in the academia and in industry, in particular for adjustable tensegrity structures that can sustain external forces when deployed. The main problem with the latter systems is checking their stability during deployment. One of the most famous methods for checking stability was developed 20 years ago by two mathematicians [1]. They showed that if the tensegrity structure is redundant then the check is simple. But if it is a determinate tensegrity structure then there is a need to calculate the velocities of all the joints and then after matrix multiplications a scalar is obtained. If the scalar is negative then it is concluded that the tensegrity system is unstable without knowing which element causes the problem and what should be done in order to stabilize it.

This paper proves that if the structure is a minimal rigid determinate structure, named Assur Graph, then there is a simple method for checking the stability. The proposed method suggests to remove a cable, calculate the curvature radius of one its inner joint and then conclude whether the structure is stable or not. In case that it was concluded that the system is unstable, then to shorten the cable so it becomes stable.

The main topic from the combinatorial method being used in this paper is the special properties of Assur Graphs, in particular their singular positions. It is proved that from all the determinate structures only the Assur Graphs have these special singular properties, upon which the proposed method and the proof relies on.
Multifrequency Excitation of a Clamped-Clamped Microbeam
Authors: Jaber Nizar R. , Ramini Abdallah , Younis Mohammad
Published: January 2016

We present analytical and experimental investigation of an electrically actuated clamped-clamped microbeam under a two-source harmonic excitation. The first frequency is swept around the first mode of vibration where the second one is fixed. These microbeams are fabricated using polyimide as structural layer coated with nickel form top and chromium and gold layers from bottom. We demonstrate the excitation of additive and subtractive type resonance. We show that by properly tuning the frequency and the amplitude of the excitation force, the frequency bandwidth of the resonator is increased. Theoretically, we solved the eigenvalue problem for different axial forces to find the natural frequencies ratio that match the experimental values. Using Galerkin method, a reduced order model is derived to simulate the static and dynamic response of the device where using three symmetric mode shapes provided a good agreement with experimental data.
Three-Dimensional Non-Linear Shell Theory for Flexible Multibody Dynamics
Authors: Han S. L. , Bauchau O. A.
Published: January 2016

In flexible multibody systems, many components are approximated as shells. Classical shell theories, such as Kirchhoff or Reissner-Mindlin shell theory, form the basis of the analytical development for shell dynamics. While such approach is capable of capturing the kinetic energy of the system accurately, it cannot represent the strain energy adequately. For instance, it is well known from three-dimensional elasticity theory that the normal material line will warp under load for laminated composite shells, leading to three-dimensional deformations that generate complex stress states. To overcome this problem, a novel three-dimensional shell theory is proposed in this paper. Kinematically, the problem is decomposed into an arbitrarily large rigid-normal-material-line motion and a warping field. The sectional strains associated with the rigid-normal-material-line motion and the warping field are assumed to remain small. As a consequence of this kinematic decomposition, the governing equations of the problem fall into two distinct categories: the global equations describing geometrically exact shells and the local equations describing local deformations. The governing equations for geometrically exact shells are nonlinear, two-dimensional equations, whereas the local equations are linear, one dimensional, provide the detailed distribution of three-dimensional stress and strain fields. Based on a set of approximated solutions, the local equations is reduced to the corresponding global equations. In the reduction process, a 9 × 9 sectional stiffness matrix can be found, which takes into account the warping effects due to material heterogeneity. In the recovery process, three-dimensional stress and strain fields at any point in the shell can be recovered from the two-dimensional shell solution. The proposed method proposed is valid for anisotropic shells with arbitrarily complex through-the-thickness lay-up configuration.
Investigating Multiscale Phenomena in Machining: The Effect of Cutting-Force Distribution Along the Tool’s Rake Face on Process Stability
Authors: Molnár Tamás G. , Insperger Tamás , Hogan S. John , Stépán Gábor
Published: January 2016

Regenerative machine tool chatter is investigated in a nonlinear single-degree-of-freedom model of turning processes. The nonlinearity arises from the dependence of the cutting-force magnitude on the chip thickness. The cutting-force is modeled as the resultant of a force system distributed along the rake face of the tool. It introduces a distributed delay in the governing equations of the system in addition to the well-known regenerative delay, which is often referred to as the short regenerative effect. The corresponding stability lobe diagrams are depicted, and it is shown that a subcritical Hopf bifurcation occurs along the stability limits in the case of realistic cutting-force distributions. Due to the subcriticality a so-called unsafe zone exists near the stability limits, where the linearly stable cutting process becomes unstable to large perturbations. Based on center-manifold reduction and normal form calculations analytic formulas are obtained to estimate the size of the unsafe zone.
Analysis of Users and Designers’ Cognitive Processes in Interaction Design Activities
Authors: Filippi Stefano , Barattin Daniela
Published: January 2016

Over the years, the increasing importance of interaction issues has suggested involving final users in design teams. This involvement requires a careful reasoning in order to maximize the users’ contribution. The research described in this paper aims at this maximization based on considerations about cognitive processes. The situated FBS framework — an existing tool to describe designers’ reasoning — is exploited to analyze the users and designers’ cognitive processes while they are designing together. The quantification of the cognitive effort allows highlighting and managing peaks, possible further interactions and missing activities. The result is a revised release of the design process, with a redistribution of the effort, an enhancement of the user-designer dialogue and the introduction of a new activity.
Dynamics of Thin-Film Piezoelectric Vertical-Rotational Scanning Actuator
Authors: Rhee Choong-Ho , Qiu Zhen , Choi Jongsoo , Wang Thomas D. , Oldham Kenn R.
Published: January 2016

Certain advanced optical endomicroscopy techniques, including dual axes confocal and multi-photon microscopy, require the ability to perform a combination of large displacement axial and fast lateral scanning in a small form factor, to generate real-time vertical cross sectional images in vivo. Vertical translational microactuators with 200 μm or more of axial scanning range have been coupled with passive internal scanning mirrors achieving up to ±6° mechanical scanning angle, suitable for imaging applications. This paper examines the influence of nonlinearities associated with large axial stroke on actuator dynamics. Coupling of internal mirror platform resonance with lateral compliance of the axial scanning stage is found to produce dramatic variation in resonant frequency of the mirror at varying stage heights. Smaller non-idealities are identified in asymmetrical stage rotation and piezoelectric forcing.
A Comparison of Quarter, Half and Full Vehicle Models With Experimental Ride Comfort Data
Authors: Hamersma Herman A. , Els Schalk
Published: January 2016

The ride comfort of a vehicle is one of the first parameters used to evaluate its performance. Ride comfort has been one of the important research topics since the dawn of the automobile. With the improvement in computational capability, vehicle engineers have modeled vehicles with increasing complexity. Initially vehicles were simplified to quarter car models, where a quarter of the vehicle was modeled with two degrees of freedom (the vertical translation of the sprung and unsprung masses). The “pitch-bounce” model has four degrees of freedom, representing the pitch rotation and vertical translation (bounce) of the vehicle body and chassis and the vertical translation of the front and rear axles and wheels. Finally, with the development of multi-body systems (MBS) software, there is the possibility to model the full vehicle with suspension kinematics and numerous degrees of freedom. The full vehicle model used for this study has 15 unconstrained degrees of freedom and experimentally determined center of mass and inertias. This paper compares the response of a quarter car, pitch-bounce and full vehicle model with the measured response of an actual vehicle.
Mesh Generation With a Standardized Headform for CFD Simulations of Particle Aspiration
Authors: Lei Zhipeng , Yang James
Published: January 2016

The aspiration of contaminated airborne particles is a big concern for healthcare workers. Computational Fluid Dynamics (CFD) method has been widely used to simulate breathing airflow and particle aspiration. In CFD simulations of particle aspiration, digital human heads have been integrated into chamber models for mesh generation. Facial dimensions influence the breathing flow pattern and the particle aspiration in the literature; however the existing CFD studies have never included standardized headforms developed from an anthropometric survey of a large American worker population. This study proposed a CFD mesh generation method for particle aspiration simulations based on a medium size standardized headform. The medium headform is one of five National Institute for Occupational Safety and Health (NIOSH) standardized headforms that represent U.S. healthcare workers. To simulate a headform sitting in the middle of a chamber, the volume between the headform and the chamber was meshed. A boundary layer of prism elements covered the headform surface, and a tetrahedral mesh filled the rest of the volume. As an application of the CFD meshes, CFD simulations for particle aspiration were conducted. Velocity fields in the chamber, inhalation flow patterns, and aspiration efficiencies were determined. Further, a grid independency study verified the simulation results and the quality of the CFD meshes.
Integrated Creativity and Play Environments in Design and Engineering Processes
Authors: Wendrich Robert E.
Published: January 2016

The umpire whispers: “Please Play”. We sort of play. But it’s all hypothetical, somehow. Even the ‘we’ is theory: I never get quite to see the distant opponent, for all the apparatus of the game [1]. We find no reason to abandon the notion of play as a distinct and highly important factor in the world’s life and doings. All play means something. If we call the active principle that makes up the essence of play, ‘instinct’, we explain nothing; if we call it ‘mind’ or ‘will’ we say too much. However we may regard it, the very fact that play has a meaning implies a non-materialistic quality in the nature of the thing itself [2]. This paper builds on the notion of integration of creativity and play in design and engineering environments. We show results of ongoing research and experimentation with cyber-physical systems (CPS) and multi-modal interactions. The use of computational tools for creative processing and idea generation in design and engineering are mostly based on commonly available 2-D or 3-D CAD programs, applications and systems. Computer-generated creativity is mostly based on combinatorial power and computational algorithms of the intrinsic system duly orchestrated by the user to manifest outcomes on a variety of processes. However, integrated game-based CPS ecosystems could enhance the uptake of play, imagination and externalization within the design and engineering process.
An Automatic Method for Sketching of Planar Simple and Multiple Joint Kinematic Chains
Authors: Ding Huafeng , Huang Peng , Huang Zhen , Kecskeméthy Andrés
Published: January 2016

The sketching of mechanisms (kinematic chains) shows designers a visual understanding of the interrelationship among links and joints in mechanical design, but sketching of mechanisms in manually in conceptual design stage is time-consuming and inefficient. In this paper, a fully-automatic method for sketching of planar simple and multiple joint kinematic chains is proposed. First, the complete sets of the topological structures (topological graphs and contracted graphs) of both simple and multiple joint kinematic chains are introduced. Then an algorithm for the layouts of the contracted graphs with minimal edge crossings is proposed. Third, the expression set of binary sub-paths derived from a topological graph is obtained for the sketching of the simple joint kinematic chain, and based on the sketching of the simple joint kinematic chains the sketching of corresponding multiple joint kinematic chains is obtained. Finally, both simple and multiple joint kinematic chains with numbers of links and numbers of basic loops are provided in batch as examples to show the effectiveness of the method.
Review, Categorization and Comparison of 1 DOF Static Balancers
Authors: Steinthorsson Asthor T. , Aguirre Milton E. , Dunning Gerard , Herder Just L.
Published: January 2016

A static balancer is a mechanism used to force compensate mechanical systems and has been used in applications such as improving haptic feedback in surgical instruments and lowering motor loads in robotic systems. Currently no complete overview exists of all SB methods, this paper can be seen as an extension to earlier work by introducing more static balancing categories and methods. The goal is to have a comprehensive overview of state-of-the-art to aid designers in selecting the appropriate static balancer technology for mechanical systems. Existing designs are categorized based on the energy storage mechanism, e.g. elastic energy storage mechanisms. Critical design parameters are extracted from published literature to form the basis of comparison of the different categories. A performance criterium is defined to illustrate balancing capabilities as a function of system size. The three comparison parameters are: CompensatedForceVolume,SBStrokeVolume,EnergyVolume The comparison results show that compliant flexure balancers are the best selection for balancing systems while keeping minimal size. Theoretical calculations show that there is still ample room to improve current balancers with regard to the chosen balancer criteria.
A Lie Group Formulation of the Newton-Euler Equations and its Application to Robot Dynamics
Authors: Chen Genliang , Wang Hao , Zhong Yong , Yu Haidong
Published: January 2016

Based on the screw theory, this paper presents a Lie group formulation for robot dynamics. Regarding the screws and co-screws as elements of se(3) and its dual se*(3), the shifting law and change-of-coordinates of screw quantities can be uniformly interpreted as the adjoint transformations associated with pure translation and rotation of rigid displacements, respectively. The acceleration screw which enables the Newton-Euler equations of a rigid body to behave in a screw-like manner, is defined with intuitive interpretations. As a result, the advantages of Lie group formulation in robot kinematics can be extended to dynamics, so that both kinematics and dynamics can be formulated about an arbitrary point initially and then transformed to any other. Based on the principle of virtual work, the system N-E equations can be solved conveniently for both forward and inverse dynamics of serial robots. By taking advantage of the adjoint representations for the Lie algebra and its operations, only matrix calculations are required, avoiding the ad hoc definitions and notational conventions, to derive the system dynamic equations.
Preliminary Computation on NOx Emission Reduction for Different Temperatures
Authors: Khan Jobaidur R.
Published: January 2016

Wet compression is an enhancing tool for power augmentation in land based gas turbine system. One of the advantages of wet compression is NOx reduction. High exhaust temperature (in the range of 1300 and 1400 K) from combustion chamber is responsible for NOx generation. High amount of NOx causes acid rain in the industrial area, which is a big concern. As wet compression reduces NOx emission, it is very important to validate this fact. Comparison needs to be made between the combustion of natural gas (methane mainly) with the combustion of same with air in reduced temperature with the presence of water vapor. As a preliminary step of this, NOx emission needs to be modelled with proper prediction of it in a natural gas combustion environment. As a preliminary study, a simple rectangular geometry is considered here. Result shows that NOx emission is reduced with lower temperature, which needs to be validated further.
A More Balanced Design Approach for Preserving the Usability of a Peruvian Cookstove
Authors: Thacker Kendall S. , Barger McCall , Mattson Christopher A.
Published: January 2016

Over the past decade, a large amount of research has been dedicated to improving the efficiency and reducing the emissions of biomass cookstoves. The trade-off from placing such an emphasis on these two objectives is that improved cookstoves are often not as functional or desirable to the end user in comparison to their traditional cookstove. Thus, users often abandon their new improved cookstoves and sustained use is not achieved. In order for improved cookstoves to be more impactful, a different design approach is needed; improved cookstoves must be designed for usability, even at the expense of higher efficiencies or lower emissions. This paper explores the benefits of this alternative approach, which is demonstrated in the design of a replacement biomass cookstove for residents living in the Tambogrande region of Peru. The heavy use of biomass cookstoves in this small collection of villages, has resulted in many health and environmental problems for the residents. Recent field studies revealed that residents were pleased with the functionality of their traditional channel stove, yet also desired to have a stove that cooks faster, consumes less fuel, and emits less smoke. The resulting design includes a set of adaptable, inexpensive pot skirts that can be integrated with their current channel stove. These pot skirts allow for varying sizes and number of pots, as well as allow traditional fuels to be used. Despite a usability focused design approach, the pot skirts still improved the technical performance of the cookstove by improving thermal efficiency by 25.8%, decreasing time to boil by 26.0%, and decreasing fuel consumption by 24.7%. These results demonstrate that a usability focused design can still yield significant performance improvements while achieving a high level of user functionality.
Adaptive Operation Decisions in Net Zero Building Clusters
Authors: Odonkor Philip , Lewis Kemper
Published: January 2016

In light of the growing strain on the energy grid and the increased awareness of the significant role buildings play within the energy ecosystem, the need for building operational strategies which minimize energy consumption has never been greater. One of the major hurdles impeding this realization primarily lies not in the lack of decision strategies, but in their inherent lack of adaptability. With most operational strategies partly dictated by a dynamic trio of social, economic and environmental factors which include occupant preference, energy price and weather conditions, it is important to realize and capitalize on this dynamism to open up new avenues for energy savings. This paper extends this idea by developing a dynamic optimization mechanism for Net-zero building clusters. A bi-level operation framework is presented to study the energy tradeoffs resulting from the adaptive measures adopted in response to hourly variations in energy price, energy consumption and indoor occupant comfort preferences. The experimental results verify the need for adaptive decision frameworks and demonstrate, through Pareto analysis, that the approach is capable of exploiting the energy saving opportunities made available through fluctuations in energy price and occupant comfort preferences.
Integrated Capture and Representation of Product Information in Computer-Aided Product Development
Authors: Lejon Erik , Lundin Michael , Dagman Andreas , Jeppsson Peter , Näsström Mats
Published: January 2016

This paper features the implementation and evaluation of a proposed approach for information capture and representation integrated into the existing design environments at two manufacturing companies. A tool has been developed that automatically derives information from the CAD system during design and provides users with the means to capture product information that has previously been documented outside of the CAD system. Product information is managed in a PLM data model and becomes, once stored, the foundation for providing tailored views of information.

Feedback from the evaluation shows that the prescribed approach was preferred to the current one and that it would likely provide value to users, both authors and consumers, of product information. This approach can reduce the time required to capture the pertinent product information. However, the primary savings are likely to be indirect as a result of increased consistency, understanding, and the potential (re)use of product information.

The approach and tools presented constitute another step toward providing each stakeholder with more efficient, intuitive, contextual, and purposeful support for information capture and representation in computer-aided product development.
Studying the Impact of Incorporating an Additive Manufacturing Based Design Exercise in a Large, First Year Technical Drawing and CAD Course
Authors: Chen Tian , Egan Paul , Stöckli Fritz , Shea Kristina
Published: January 2016

Additive Manufacturing (AM) is a revolutionary technology in the manufacturing sector, although it has yet to become a cornerstone of formal engineering education. This paper discusses the procedure, result, and impact of incorporating physical prototyping, design iteration, and Design for Additive Manufacturing (DfAM) in a first-year, first-semester technical drawing and CAD course. In the course, students design balloon powered model car assemblies and are expected to learn core concepts of engineering design, such as modeling, assemblies, and tolerancing. The course consists of 473 students that each design up to two unique model cars. These model cars are fabricated using AM from these CAD designs and returned to students for assembly. Surveys are given to students to empirically validate the usefulness of incorporating AM in the course, with regards to motivating students and improving their ability to accurately translate imagined designs from CAD to physical products. The results show improvement in student intrinsic motivation concerning CAD processes. Student design abilities are also assessed: when student designs do not function as intended, it corresponds with a greater mismatch in how they imagine their CAD design in comparison to its final physical assembly. The mismatch on average decreases for students who design a second model car, which suggests an improvement in design skills. As a whole, our findings demonstrate the feasibility and benefits of including AM in a first-year course, particularly with respect to improving student motivation and their development of key CAD-related skills. Such motivation and skill development is particularly important early in an engineer’s career as it can impact their potential to learn and design over the course of their budding career.
Scientific Foundations for Systems Engineering: Challenges and Strategies
Authors: Davendralingam Navindran , Sha Zhenghui , Moolchandani Kushal , Maheshwari Apoorv , Panchal Jitesh H. , DeLaurentis Daniel A.
Published: January 2016

There is an increasing realization of the need for fundamental research in the science of systems engineering. The International Council on Systems Engineering vision document calls for theoretical foundations for systems architecting, systems design and systems understanding. During a recent NSF workshop, a number of knowledge areas ranging from mathematics, information sciences, physical sciences, systems science to human and social sciences were identified as possible sources from which the scientific foundation of systems engineering can be enhanced. However, the primary challenge facing the community lies in orchestrating the breadth and diversity of the many knowledge areas into a cohesive foundation. This paper briefly surveys systems science-related efforts across multiple application domains. The specific objectives in this paper are to present a classification of initiatives for developing foundations for systems engineering, and to discuss the challenges, and potential strategies forward, associated with systems science research. The classification is discussed using two case examples — the Internet and the air transportation system. Through these examples, some of the key research challenges and strategies are exemplified.
Anti-Lock Wheel Slip Control With an Adaptive Searching Algorithm for the Optimal Slip
Authors: Pan Ning , Yu Liangyao , Zhang Lei , Wang Zhizhong , Song Jian
Published: January 2016

An adaptive searching algorithm for the optimal slip during ABS wheel slip control is proposed. By taking advantage of the fluctuation of wheel slip control, the direction towards the optimal slip can be found, and the target slip calculated by the algorithm asymptotically converged to the optimal slip, which is proved using the Lyapunov theory. A gain-scheduling wheel slip controller is developed to control the wheel slip to the target slip. Simulations on the uniform road and on the road with changed friction are carried out to verify the effectiveness of the proposed algorithm. Simulation results show that the ABS algorithm using the proposed searching algorithm can make full use of the road friction and adapts to road friction changes. Comparing with the conventional rule-based ABS, the pressure modulation amplitude and wheel speed fluctuation is significantly reduced, improving control performance of ABS.
Improving Multiobjective Multidisciplinary Optimization With a Data Mining-Based Hybrid Method
Authors: Xu Hongyi , Chuang Ching-Hung , Yang Ren-Jye
Published: January 2016

Multiobjective, multidisciplinary design optimization (MDO) of complex system is challenging due to the long computational time needed for evaluating new designs’ performances. Heuristic optimization algorithms are widely employed to overcome the local optimums, but the inherent randomness of such algorithms leads to another disadvantage: the need for a large number of design evaluations. To accelerate the product design process, a data mining-based hybrid strategy is developed to improve the search efficiency. Based on the historical information of the optimization search, clustering and classification techniques are employed to detect low quality designs and repetitive designs, and which are then replaced by promising designs. In addition, the metamodel with bias correction is integrated into the proposed strategy to further increase the probability of finding promising design regions within a limited number of design evaluations. Two case studies, one mathematical benchmark problem and one vehicle side impact design problem, are conducted to demonstrate the effectiveness of the proposed method in improving the searching efficiency.
Modified Bayesian Kriging for Noisy Response Problems for Reliability Analysis
Authors: Gaul Nicholas J. , Cowles Mary Kathryn , Cho Hyunkyoo , Choi K. K. , Lamb David
Published: January 2016

This paper develops a new modified Bayesian Kriging (MBKG) surrogate modeling method for problems in which simulation analyses are inherently noisy and thus standard Kriging approaches fail to properly represent the responses. The purpose is to develop a method that can be used to carry out reliability analysis to predict probability of failure. The formulation of the MBKG surrogate modeling method is presented, and the full conditional distributions of the unknown MBKG parameters are presented. Using the full conditional distributions with a Gibbs sampling algorithm, Markov chain Monte Carlo is used to fit the MBKG surrogate model. A sequential sampling method that uses the posterior credible sets for inserting new design of experiment (DoE) sample points is proposed. The sequential sampling method is developed in such a way that the newly added DoE sample points will provide the maximum amount of information possible to the MBKG surrogate model, making it an efficient and effective way to reduce the number of DoE sample points needed. Therefore, the proposed method improves the posterior distribution of the probability of failure efficiently. To demonstrate the developed MBKG and sequential sampling methods, a 2-D mathematical example with added random noise is used. It is shown how, with the use of the sequential sample method, the posterior distribution of the probability of failure converges to capture the true probability of failure. A 3-D multibody dynamics (MBD) engineering block-car example illustrates an application of the new method to a simple engineering example for which standard Kriging methods fail.
Lightweight, Low-Cost, Compliant Grasper for UAV-Based Pick-and-Place Operations
Authors: Welch Charles R. , Akbarisamani Saeideh , Detweiler Carrick , Nelson Carl A.
Published: January 2016

Grasping and manipulating objects remains an area of interest in robotics for a variety of applications. An emerging area is the use of graspers in conjunction with unmanned aerial vehicles (UAVs), e.g., for construction, agriculture, and military operations. This paper presents the design of a compliant grasper, which has a simple, low-cost mechanism to grasp different-sized delicate objects. The grasper was refined through an FEA model to optimize the key compliance features. It was tested on nine different objects of varying dimensions and weights. The grasper grasped and lifted objects up to 10 times its own weight; however, it is most reliable with lighter objects. A preliminary experiment with integration on a UAV demonstrated the grasper’s intended functionality.
Mitigation of the Effects of High Levels of High-Frequency Noise on MEMS Gyroscopes Using Microfibrous Cloth
Authors: Soobramaney Pregassen , Flowers George , Dean Robert
Published: January 2016

MEMS gyroscopes are being used in a variety of applications such as camcorders, vehicle stability control and game controllers. Sometimes they are used in harsh environments such as high levels of high-frequency noise. If the frequency of the noise coincides with the natural frequency of the gyroscope, the output of the latter is corrupted. Experiments were performed to demonstrate the effects of noise on MEMS gyroscopes. The focus of this research is to investigate a passive approach to attenuate the effects of noise on MEMS gyroscopes using microfibrous cloth. The candidate materials are made by intermingling and fusing micro metal fibers together using cellulose in wet-lay papermaking technique and sintering of the resulting product to remove the cellulose and bonds the metallic fibers. In this regard, four types of nickel microfibrous material were fabricated using three diameters of nickel fibers. The Delany-Bazley analytical acoustical model was used to determine the optimum acoustical properties of the material. The properties were then used to calculate the absorption coefficients of the microfibrous media. Enclosures were then designed and fabricated from these materials to evaluate the noise attenuation effects on MEMS gyroscopes. Acoustical tests performed in a reverberation room show up to 90% reduction in the amplitude of the effects of noise. The results from simulation modeling and from these experimental evaluations are presented and discussed.
Stochastic Event Detection in Needle-Tissue Interaction
Authors: Kim Inki , Gordon Adam , Miller Scarlett R.
Published: January 2016

Over the last decade, many dynamic models that express needle-force relationships under tissues of varying mechanical properties have been developed. While great progress has been made in the development of these high-fidelity models, they are only valid within certain boundary conditions limiting their match with reality. This gap in realism is aggravated by variability in human tissues, needles, and the modes of interaction with the tissue. In an effort to develop more realistic models, the current paper was developed to create and test an event (i.e. changes of variability) detection method based on the probability distribution of residues — difference between force models and measurements. To obtain force measurements, we repeated robotic-driven needle insertion into a simulated mannequin. Needle types and tissue thickness were varied in the measurements in order to add realistic variability. To obtain the force model, the measurement data was used as an input to a Grey-Box model. From the measurements and models, we estimated the probability distribution of residues. For validation, a Gaussian-Mixture Model (GMM) was used to confirm the stochastic model successfully distinguishes the residual distributions under different variability. We found that by examining the residual distributions it is possible to detect unexpected variability in needle-tissue interactions. The findings from this paper have implications for developing real-time event detection methods and simulating patient-variability in haptic applications.
Implementing Creativity Evaluation Tools Into the Concept Selection Process in Engineering Education
Authors: Starkey Elizabeth M. , Gosnell Christopher A. , Miller Scarlett R.
Published: January 2016

In design research, creativity assessment methods have been studied to obtain quantitative measurements of design novelty and feasibility for use in the concept selection process. However, little research exists that studies the application and implementation of these tools by engineering students on grade-dependent class projects. In this study, teams of undergraduate engineering design students evaluated their own early product sketches using informal team discussions, a creativity scale and our Tool for Assessing Semantic Creativity (TASC) adjective selection method. The resulting evaluations were compared and contrasted with evaluations obtained from the widely adopted Shah Vargas-Hernandez and Smith (SVS) method and expert ratings. These findings demonstrate that our TASC adjective selection method of evaluating design creativity is tapping into similar constructs of creativity as informal team discussions and expert evaluations. They also indicate that the SVS method does not appear to be evaluating creativity as perceived by engineering design students or experts. The results of this study can be used to understand how students make decisions during the concept selection process and how tools can be developed or implemented in the classroom setting to aid in this process.
A Geometry Projection Method for the Optimal Distribution of Short Fiber Reinforcements
Authors: Norato Julián A.
Published: January 2016

This paper presents an optimization method for optimally distributing short fibers of variable length for the reinforcement of structural components for stiffness. Unlike standard density-based and level set topology optimization methods that generally render material distributions with variable member size, the proposed method projects an explicit geometry model onto a continuous density field. The proposed method inherits the benefits of density-based topology optimization methods, namely simplified and efficient primal and sensitivity analyses on a fixed grid, fast convergence, robustness, and amenability to standard finite element methods for the analysis and to nonlinear programming algorithms for the optimization. The explicit geometry representation of the fibers provides a suitable description of the short fibers, and therefore the designs produced by the proposed method have potential for manufacturing using, for example, processing methods for the fabrication of micro-architectured materials. Examples of reinforcement distribution design for two-dimensional structures in plane stress demonstrate the method.
A Virtual Reality Approach for Minimizing Information Loss in Multi-User, Scalable Environments
Authors: Dickens Bryan , Sellers Steven , Harms Gabe , Shartle Owen , Tucker Conrad S.
Published: January 2016

The authors of this work propose a virtual reality approach that overcomes two fundamental challenges experienced in physical learning environments; i) variations in audial quality, and ii) variations in visual quality, in an effort to achieve individual customization of information content. In physical brick and mortar environments, the dissemination of information is influenced by the medium that the information travels through, which is typically distorted by line of sight constraints and constraints that distort sound waves. The fundamental research question is how to achieve consistent quality of information being disseminated, as the number of audience members increases? There exists a knowledge gap relating to the creation of a scalable, networked, system for enabling real time, information exchange. The authors propose a virtual reality approach to address these limitations of physical learning spaces that minimizes the variability in audial and visual information dissemination. A real time, networked architecture is proposed that enables multiple individuals to simultaneously experience the same quality of audial and visual information, based on the optimal geospatial position for audial and visual exposure determined. A case study is introduced that first quantifies simulations of the audial and visual information loss experienced by audience members receiving information at different geospatial locations in a brick and mortar environment. This information loss is compared against the proposed virtual reality architecture that minimizes the variation in information dissemination. The authors demonstrate that the proposed solution is an improved, scalable multi-user system, unlike brick and mortar environments that are constrained by size and geospatial positioning.
Visualization of Headlight Illumination for the Virtual Prototyping of Light-Based Driver Assistance Systems
Authors: Berssenbrügge Jan , Trächtler Ansgar , Schmidt Christoph
Published: January 2016

Driving simulators that are capable of a simulation of a virtual drive at night are increasingly used for the virtual prototyping of light-based driver assistance systems. Here, the interplay between driver and assistance system, which enhances the illumination of the road ahead of the vehicle, is investigated. For such investigations, special driving simulators are applied that enable not only a standard driving simulation but also cover the special requirements for the visualization of a driving scenery at night, the simulation of automotive headlights during a virtual drive at night, and the interface to a headlight control module (HCM) that operates the physical headlight prototypes.

In this paper, we present the visualization system of the reconfigurable driving simulator from the research project TRAFFIS. We describe the special application focus on the virtual prototyping of a light-based driver assistance system from our project partner Varroc Lighting Systems. The light-based DAS bases on a headlight prototype that combines a glare-free high beam (GFHB) function and a predictive adaptive frontlighting system (PAFS) for glare-free driving with maximized headlight time.
Investigating the Heterogeneity of Product Feature Preferences Mined Using Online Product Data Streams
Authors: Singh Abhinav S. , Tucker Conrad S.
Published: January 2016

This work investigates the “must have” and “deal breaker” product feature preferences expressed by users of online platforms (e.g., customer review websites or social media networks) in order to inform designers of product features that should be investigated during the next iteration of a product’s launch. Existing design literature highlights the risks of aggregating group preferences, and suggest that design teams should instead, focus on maximizing enterprise value by optimizing the attributes of a product. However, design knowledge about products and product attributes are influenced by market information, which is dynamic and difficult to acquire. The use of online product review platforms has emerged in the design community as a viable source of product data acquisition and demand model prediction. However, as the heterogeneity of product preferences increases, so does the complexity of understanding which product attributes should be optimized by the design team to maximize enterprise value. These challenges are exacerbated in product preference acquisition techniques that rely on mining online data, as the customer is typically unknown to the designer, which limits the amount of follow up data available to be mined. By quantifying the degree of “must have” and “deal breaker” product preferences expressed online, designers will be able to understand what product-features should be omitted from next generation product design optimization models (i.e., “deal breaker” features) and what product features should be considered (i.e., “must have” features). A case study involving customer electronics mined from online customer review websites is used to demonstrate the validity of the proposed methodology.
Reducing Structural Error in Function Generating Mechanisms via the Addition of Large Numbers of Four-Bar Mechanisms
Authors: Ali Hessein , Murray Andrew P. , Myszka David H.
Published: January 2016

This paper presents a methodology for synthesizing planar linkages to approximate any prescribed periodic function. The mechanisms selected for this task are the slider-crank and the geared five-bar with connecting rod and sliding output (GFBS), where any number of drag-link (or double crank) four-bars are used as drivers. A slider-crank mechanism, when comparing the input crank rotation to the output slider displacement, produces a sinusoid-like function. Instead of directly driving the input crank, a drag-link four-bar may be added that drives the crank from its output via a rigid connection between the two. Driving the input of the added four-bar results in a function that is less sinusoid-like. This process can be continued through the addition of more drag-link mechanisms to the device, slowly altering the curve toward any periodic function with a single maximum. For periodic functions with multiple maxima, a GFBS is used as the terminal linkage added to the chain of drag-link mechanisms. The synthesis process starts by analyzing one period of the function to design either the terminal slider-crank or terminal GFBS. A randomized local search is then conducted as the four-bars are added to minimize the structural error between the desired function and the input-output function of the mechanism. Mechanisms have been “grown” in this fashion to dozens of links that are capable of closely producing functions with a variety of intriguing features.
A Cooperative Driving NLMPC for Real Time Collision Avoidance
Authors: Rosolia Ugo , Braghin Francesco , Sabbioni Edoardo , Alleyne Andrew , De Bruyne Stijn
Published: January 2016

A decentralized cooperative driving Non Linear Model Predictive Control (NLMPC) approach for path following and collision avoidance is presented in this paper.

The proposed decentralized approach is based on an information network, which communicates when two or more vehicles are near and so they might collide. In the case in which vehicles are far, online trajectory control is independently computed on-board by means of a NLMPC. When two or more vehicles get closer, trajectory control is no more independently carried out: optimal solution for these vehicles is coupled and thus their trajectories are computed dependently.

Performance of the proposed decentralized NLMPC for cooperative driving was assessed through numerical simulations involving two vehicles. Results were compared with ones of a centralized approach to assess optimality of the solution.