bluuebunny/crossref_metadata_2025 huggingface dataset:
The Impact of Industry Experience on Engineering Graduate Students’ Functional Design Modeling
Authors: Bohm Matt , Ingram Hannah , Reith Dalton , Nagel Robert , Linsey Julie
Published: November 2019

Understanding the differences in functional models between traditional full-time graduate students and graduate students working in industry may allow for a deeper understanding of the impact of an engineer’s work on their ability to model a system in terms of its functions. To explore these differences, the researchers assigned two groups of students the task of creating a functional model of a can opener. One group of graduate students was traditional full-time graduate students while the other group was comprised of graduate students who are actively working in industry as engineers in the consumer appliance sector. This paper explores both the mechanics and plausibility behind the functional models created by the two groups of students and the impact of the industry standard parameter diagrams on the functional models of the graduate students’ working in industry.

After an initial analysis of the data, the researchers noticed an abnormal trend of the industry students to include more information beyond the common functional model elements which affected their models’ logical plausibility. Because this trend seemed to occur in higher quantities in the industry students’ functional models than the traditional graduate students’ models, the researchers decided to evaluate both groups’ functional models with a rubric developed for parameter diagrams — a model format common to the industry in which the industry students were employed. After re-analyzing the functional models of both groups using the parameter diagram rubric, it was observed that the industry students’ functional models did indeed include higher traces of parameter diagrams than the average graduate student. The researchers believe this may have been due to design fixation and incomplete conceptual change in practicing engineers. Implications of this finding are discussed herein.
A Conceptual Framework and a Research Roadmap Towards Enhancing Team Working in Engineering Education
Authors: Takai Shun , Esterman Marcos
Published: November 2019

While design processes have been studied for many years, relationships among design team characteristics, teamwork, and team performance have not yet been fully understood. As such, there is no consensus on how to form design teams or enhance teamwork. In this paper, we propose a conceptual design-team effectiveness model based on team effectiveness theory in which we divide team process into two components: team member collaboration and design process. Built on this model, we then present a six-step research roadmap towards enhancing teamwork in engineering education by 1) improving methodology to form design teams and 2) finding a team-building design exercise to promote team member collaboration. We propose to improve team formation methodology by 1) comprehensively studying associations among team factors and team performance and 2) investigating how associations among team factors and team performance change with team-building design exercises. Together, we expect both team performance and team member collaboration to improve, which should lead to a better teamwork experience in engineering education.
On Nonlinear Dynamics and Control of an Inverted Flexible Pendulum System With Chaos
Authors: Kahar Hartiny , Söffker Dirk
Published: November 2019

In this paper, the dynamical behavior of a nonlinear mechanical system is considered, namely an inverted flexible pendulum excited in its base by a cart driven by a motor. In this experimental procedure, the chaotic motion of the pendulum tip was identified, in combination with a specific range of parameters. Time-frequency energy analysis is performed to be used for modeling the transition between the equilibria of the chaotic systems. Controlling the chaotic behavior of the system is realized using impulsive control method, where additive impulses are injected into the system, designed with specific impulses energy content at a specific frequency band. The experimental results are presented and discussed in detail, concentrating on how the designed impulses have to be injected to affect the system, specifically the transition between states of equilibria. The results from this experimental modeling procedure show that both additive impulse design and frequency filtering of the injected additive impulses are able to stimulate the equilibrium shift and therefore to control the chaotic behavior of the system.
Actuator Rate Limit Effects on Proportional-Integral Controller for First-Order Plus Time-Delay Systems
Authors: Wu Zhenlong , Yuan Jie , Li Donghai , Xue Yali , Chen YangQuan
Published: November 2019

Actuator rate limit deteriorates control performance with amplitude attenuation and phase delay, and may lead to system instability in process control. In this paper, great challenges for first-order plus time delay (FOPTD) systems are concerned. Based on the preliminary knowledge of the definition of rate limiter, the concept of closed-loop onset frequency with rate limiter and classic proportional-integral (PI) tuning rules, the rate limit effects on PI controller are analyzed by simulations. The results show that the rate limiter has significant influence on the stability regions of PI parameters which can be reduced greatly. Besides, PI tuning rules with the same robustness constraint can be obviously effected where Skogestad internal model (SIMC) tuning rule is more robust to the rate limit variation than that of maximize the integral gain (Åström) and robustness constrained optimization (DRO) tuning rule. These results can offer a guideline to tune PI parameters when actuators have non-ignorable rate limit for industrial applications.
Defining the Space of Feasible Transmission Designs for Retrofitting a Rear-Wheel-Drive Automobile With a Power Split CVT
Authors: Vermillion Sean D.
Published: November 2019

In this paper, we describe a strategy for modeling the feasible set of power-split continuously variable transmission (CVT) system designs for retrofitting rear-wheel-drive consumer automobiles. A design is considered feasible if it produces a higher fuel economy than the stock vehicle’s fuel economy rating. Towards modeling the feasible set of designs, we first model a vehicle with a power-split CVT system taking into account the system’s mass and CVT efficiency. In this model, the effective design variables are the mass of the transmission system, the CVT functional efficiency, and effective gear ratio defining the allowable power split through and around the CVT. We formulate the set of feasible design solutions utilizing a multiobjective optimization problem to define the boundaries of the maximum allowable system mass, minimum allowable efficiency, and minimum allowable effective gear ratio. We solve this multiobjective optimization problem using NSGA-II and fit a quadratic model to the NSGA-II results to define a surrogate model of the feasible design set. We show that this surrogate modeling approach is sufficient for predicting the feasibility of a candidate transmission design.
Multi-Resolution Energy Strategy for Battery Management System of Unmanned Ground Vehicles in Agriculture
Authors: Wang Yanan , Tian Junwei , Niu Haoyu , Wang Peng , Liao Xiaozhong , Chen Yangquan
Published: November 2019

This paper has proposed a multi-resolution energy strategy for battery management system (BMS) of unmanned ground vehicles (UGVs) in farming. On the basis of “Smart Farm” definition, battery energy consumption and management have been taken into consideration during the working process and system control. A battery energy controller has been proposed for the low-cost ($1000) UGVs designed by our lab for farming usage. Moreover, three levels of energy control loops have been developed, that is, motor control, path planning, and mission arrangement. In this way, an energy-efficient UGV can prolong its working time and also decrease the cost. The three closed-loop energy strategy of BMS provides not only separate working methods for the three levels, but also a weights way to adjust the influence of three levels on the performance of the UGV in different tasks.
On the Effect of Glassy Coatings on the Wear of a Sliding Contact via Multiphysics Modeling
Authors: Michopoulos John G. , Iliopoulos Athanasios P. , Steuben John C. , Birnbaum Andrew J. , Apetre Nicole A.
Published: November 2019

A recently developed multiphysics computational framework is exercised to predict the wear behavior of two deformable and heat conducting bodies under conditions of sliding contact. This framework enables the solution of a high dimensional thermo-mechanical problem simultaneously and tightly coupled with the associated wear evolution models for each of the wear pair bodies, thus enabling predictions of wear for both of them. Two distinct slider-base pairs are modeled. The first involves an aluminum alloy slider and a copper alloy base. The second is a pair identical to the first except it contains a thin strip of soda lime glass embedded in the surface of the base. The objective of this effort is to establish the effects of this glass layer on the wear of all participating bodies in comparison to the pair that does not contain this layer. The results indicate that while the glass layer has a wear mitigation effect for the stationary base it slightly increases the wear of the slider when compared with the respective bodies when the glass is not present.
Deep Reinforcement Learning for Transfer of Control Policies
Authors: Cunningham James D. , Miller Simon W. , Yukish Michael A. , Simpson Timothy W. , Tucker Conrad S.
Published: November 2019

We present a form-aware reinforcement learning (RL) method to extend control knowledge from one design form to another, without losing the ability to control the original design. A major challenge in developing control knowledge is the creation of generalized control policies across designs of varying form. Our presented RL policy is form-aware because in addition to receiving dynamic state information about the environment, it also receives states that encode information about the form of the design that is being controlled. In this paper, we investigate the impact of this mixed state space on transfer learning. We present a transfer learning method for extending a control policy to a different design form, while continuing to expose the agent to the original design during the training of the new design. To demonstrate this concept, we present a case study of a multi-rotor aircraft simulation, wherein the designated task is to achieve a stable hover. We show that by introducing form states, an RL agent is able to learn a control policy to achieve the hovering task with both a four rotor and three rotor design at once, whereas without the form states it can only hover with the four rotor design. We also benchmark our method against a test case that removes the transfer learning component, as well as a test case that removes the continued exposure to the original design to show the value of each of these components. We find that form states, transfer learning, and parallel learning all contribute to a more robust control policy for the new design, and that parallel learning is especially important for maintaining control knowledge of the original design.
Product Service System Design in New Situations: Prediction of Demand Surfaces From Environment
Authors: Watson Bryan C. , Telenko Cassandra
Published: November 2019

Product service systems (PSS), such as DVD rental stations or the subway, face a unique problem slowing their adoption and growth: they are uniquely dependent upon timely or expensive user data for system planning, yet user datasets are only accurate for a small part of the entire PSS. Thus, methods to use the available data effectively and use data collected in one portion of a PSS for system design in another portion could transform PSS design. PSS allow customers to purchase use of a product rather than the product itself, resulting in improved environmental sustainability. The central question examined by this work is: how can designers compensate for situations where the design environment has changed and limited user data is available to inform demand estimations? Our hypothesis is that publicly available socio-demographic and environmental variables can be used to estimate the demand outside of the boundaries previously constrained by available user data. This approach was validated by applying multivariable regressions to a major Bike Share System (BSS) Expansion, outperforming the methods utilized by the BSS operators. The approach is tested in four different design scenarios. When examining all 174 stations added in 2015, our approach shows a moderate correlation with the ideal ordering (Rho = .566, Stations = 174, p < .01), while the implemented operator ordering was only weakly correlated (Rho = .334, Stations = 174, p < .01). This work demonstrates a partial solution to the problem of transforming available user data into demand for new situations.
Nonlinear Dynamics of Nonlinear L-Shape Piezoelectric Systems for Positive and Reverse Sweep Waveform
Authors: Yao Ming Hui
Published: November 2019

This paper presents a bistable inverted L-shaped piezoelectric beam power generation structure, and its dynamic behaviors and power generation performance are studied by positive and reverse sweep waveform experiments. The piezoelectric beam includes the substructure layer and the piezoelectric layer. The material of the piezoelectric layer is the piezoelectric ceramic transducer (PZT), and the material of the substructure layer is the phosphor brass. The positive and reverse sinusoidal excitation signal is selected. The snap through phenomenon and stiffness characteristic of the system are investigated by experimental results of the positive and reverse sweep waveform. The relationship between dynamic behaviors and electrical behaviors of the system is also studied. Experimental results show that the positive and reverse sweep waveform has a great influence on vibration of the nonlinear system. Due to the hard spring characteristic of the system, the large vibration amplitude is easy to appear in the positive sweep waveform. Dynamic behaviors of the piezoelectric system are related to its electrical behaviors. When dynamic behaviors bifurcate, electrical behaviors bifurcate. These results can be applied to explore the vibration characteristic and the power generation of the nonlinear piezoelectric system.
Reinforcement Learning Content Generation for Virtual Reality Applications
Authors: Lopez Christian E. , Ashour Omar , Tucker Conrad S.
Published: November 2019

This work presents a Procedural Content Generation (PCG) method based on a Neural Network Reinforcement Learning (RL) approach that generates new environments for Virtual Reality (VR) learning applications. The primary objective of PCG methods is to algorithmically generate new content (e.g., environments, levels) in order to improve user experience. Researchers have started exploring the integration of Machine Learning (ML) algorithms into their PCG methods. These ML approaches help explore the design space and generate new content more efficiently. The capability to provide users with new content has great potential for learning applications. However, these ML algorithms require large datasets to train their generative models. In contrast, RL based methods take advantage of simulation to train their models. Moreover, even though VR has become an emerging technology to engage users, there have been few studies that explore PCG for learning purposes and fewer in the context of VR. Considering these limitations, this work presents a method that generates new VR environments by training an RL agent using a simulation platform. This PCG method has the potential to maintain users’ engagement over time by presenting them with new environments in VR learning applications.
An Origami Crease Pattern Generating Methodology for “Origami 3D Printer”
Authors: Yang Yang , Hagiwara Ichiro , Diago Luis , Shinoda Junichi
Published: November 2019

The additive 3D printer (hereafter called Add-3D) creates a 3D object with materials being added together layer by layer. Before printing an object, some professional processes are indispensable, such as creating the 3D printable models by computer-aided design (CAD), or 3D scanner, and STL data modification, which are difficult for normal families. As we know, primordially, origami is the ancient art of folding a flat-piece of paper into a 3D shape, that even can be played by kids. So we aim to develop an Origami 3D printer (hereafter called Ori-3D) that can be used by ordinary families with the features of effort and no size limit of model. In Ori-3D, the object is constructed by human hands or by an Origami robot using 2D patterns generated from 3D data (obtained from photos or CAD). Ori-3D includes the following steps: 1) the surface of an object is segmented to several developable surfaces as large as possible using segmentation technique which is used in reverse engineering system. 2) Each developable surface is developed to 2D pattern with mountain & valley lines and glue parts. 3) The 2D crease pattern is optimized by a tree structure method to be easily folded by an Origami Robot. 4) With Origami robot, the object is easily constructed from the improved 2D crease pattern. This paper focuses on discuss the steps 1∼ 3: generation of the 2D crease pattern.
Semantic Network Differences Across Engineering Design Communication Methods
Authors: Lopez Christian E. , Zhao Zixuan V. , Tucker Conrad S.
Published: November 2019

Engineering designers have a variety of methods at their disposal when it comes to communicating an idea (e.g., Linguistic, Pictorial, Virtual). Studies have explored how these methods affect the idea generation process, revealing that some methods can induce design fixation and reduce creativity. Moreover, studies reveal that depending on the communication methods and a receiver’s familiarity with the idea conveyed, the amount of relevant information transmitted could vary. Hence, based on previous studies, it is hypothesized that different communication methods and a receiver’s familiarity can impact a receiver’s ability to construct and interpret the information conveyed. To test this hypothesis, an experiment is conducted in which multiple methods are used to communicate different product ideas to individuals (N = 370). Participants are asked to describe the products in their own words and provide details about their functions. A text-mining approach is used to analyze the semantic structure of their responses. The results reveal that dissemination methods affect the consistency of participants’ responses, as well as the diversity of words used to describe a product idea or its functions. This knowledge can help designers in the selection of an appropriate method, given the design intention and help them leverage different methods to maximize communication effectiveness during the different stages of the design process.
Playing a Musical Saw With a Humanoid Robot: Investigation for Industrial Automation
Authors: Mishima Akira , Fuke Yusuke , Miura Atsuyuki , Hirogaki Toshiki , Aoyama Eiichi
Published: November 2019

The objective of this study was to automate the dual-arm coordination of a humanoid robot when using a musical saw as a percussion instrument to produce a target sound. We examined the striking motion of the robot using its elastic stiffness, the change in vibration caused by the striking tool resulting from the robot arm-applied force on the saw, and dual arm cooperative motion based on striking sound feedback. To accomplish this, the frequency characteristics of the musical saw and the location of sound generation were determined. Based on the characteristics of the striking task and using an acoustic recognition system, we then developed an impact sound feedback system that could provide performance control of the two humanoid robot arms. The results indicate that humanoid robot can play the musical saw by controlling the curvature freely to achieve target sounds.
Mechanism Singularities Revisited From an Algebraic Viewpoint
Authors: Li Zijia , Mueller Andreas
Published: November 2019

It has become obvious that certain singular phenomena cannot be explained by a mere investigation of the configuration space, defined as the solution set of the loop closure equations. For example, it was observed that a particular 6R linkage, constructed by combination of two Goldberg 5R linkages, exhibits kinematic singularities at a smooth point in its configuration space. Such problems are addressed in this paper. To this end, an algebraic framework is used in which the constraints are formulated as polynomial equations using Study parameters. The algebraic object of study is the ideal generated by the constraint equations (the constraint ideal).

Using basic tools from commutative algebra and algebraic geometry (primary decomposition, Hilbert’s Nullstellensatz), the special phenomenon is related to the fact that the constraint ideal is not a radical ideal. With a primary decomposition of the constraint ideal, the associated prime ideal of one primary ideal contains strictly into the associated prime ideal of another primary ideal which also gives the smooth configuration curve. This analysis is extended to shaky and kinematotropic linkages, for which examples are presented.
A Model for Vehicular Interactions Extracted From Real-World Traffic Data
Authors: Patel Jay , Karamouzas Ioannis , Ayalew Beshah
Published: November 2019

With the advent of connected and automated vehicles, naturalistic traffic modeling is becoming increasingly important for the purposes of congestion control via cooperative driving and intelligent traffic management. The focus of this paper is to develop a data-driven traffic interaction model which can help in the development of multi-agent automated driving control schemes that mimic and blend with other human-driven vehicles. To that end, a probabilistic data analysis approach is used to derive an energy function that describes interactions between vehicles on highways. These interactions arise from the psychophysics of humans driving the vehicles. The analysis suggests the existence of a simple interaction law between human-driven vehicles that is based on the expected time it takes for the vehicles to collide. The approach taken in this paper helps in analyzing probable states that the individual vehicles in the traffic would have, thereby facilitating the development of intelligent traffic management tools that account for individual vehicle states.
Optimization of a 2DOF Positioning Stage Using Corrugated Flexure Units Under Stress Constraints
Authors: Wang Nianfeng , Yue Fan , Li Canran , Zhang Xianmin
Published: November 2019

The paper introduces the design optimization for micro-positioning stage using corrugated flexure (CF) units under stress constraints. The stress state is solved and the maximum displacement under stress constraints is deduced. The natural frequency formula of the micro-positioning stage is further derived from the results of the stiffness matrix. Finally, the stage configurations corresponding to the maximum displacement are optimized by restricting the off-axis/axial stiffness ratio and natural frequency of the stage.
Model Based Root Cause Analysis of Manufacturing Quality Problems Using Uncertainty Quantification and Sensitivity Analysis
Authors: Otto Kevin , Mosqueda Josefina Sanchez
Published: November 2019

Diagnosing faulty performance deviations of electro-mechanical systems can be difficult, given the multitude of components and features which could contribute as root causes. Yet this is often a problem in manufacturing, where only some of the units built do not meet performance requirements only some of the time. In this context, product and process simulation studies can aid in diagnosis. This paper aims to develop a practical workflow and toolchain to guide use of uncertainty quantification and sensitivity analysis methods for root cause analysis of manufacturing processes. This approach offers more rapid diagnosis than the typical approach using some form of iterative experimentation such as Red-X, fault tree analysis and when in high volume production, statistical analysis and potentially machine learning. Here, part processes, features and assembly deviations are used as inputs to product performance simulation to understand their detrimental impact. The large set of possible process inputs can be systematically varied and contributions to system performance deviation computed. To do this simply using uncertainty quantification and sensitivity analysis is impractical, as the problem is too large. Rather, a sequential refinement workflow is developed to define the problem and possible causes, understand ability model causes, screen causal variables, and then apply quasi-Monte-Carlo uncertainty quantification sampling and global sensitivity analysis. This provides computational guidance to ascertain which manufacturing process inputs are more likely causes of performance deviations on manufactured units.
Heuristic Approach for Warehouse Resources and Production Planning Optimization: An Industry Case Study
Authors: Rosetti Roberto , Sturari Mirco , Frontoni Emanuele , Loncarski Jelena , Cicchitti Anselmo , Iavazzo Enrico , Gualtieri Diego
Published: November 2019

Industrial sector for production of manufacturing machinery and equipment is a very competitive and difficult market to deal with. Difficulties increase in areas that involves the design, manufacturing and assembly of large production machines. In fact, in this case the effort to produce a single item is much bigger in time, money and resources with respect to other areas. Long time for production paired with a not accurate usage of internal resources can produce a large number of unused components and semi-finished products. This paper presents a real case study of a company leader in the designing and manufacturing machinery for disposable hygienic products and highly automated liquid filling integrated systems. Each product is a huge assembly of components and semi-finished products and many of them are not used for production even if they are stored in company’s warehouses. This is due to the logistic and human factors that can be managed and corrected. In this paper a math-heuristic approach for warehouse resources and components procurement optimization is presented. A real instance related to a commission has been solved and results are presented and analyzed.
Computational Design of Active Lattice Structures for 4D Printed Pneumatic Shape Morphing
Authors: du Pasquier Cosima , Koller Pascal , Stankovic Tino , Shea Kristina
Published: November 2019

With advances in 3D printing and digital fabrication an opportunity is presented to realize highly customized designs whose shape can change and adapt to facilitate their functionality. A computational design method to determine the configuration of 2D pneumatic shape morphing lattices using a direct search method is implemented and assessed. The method is tested using a Kagome unit cell lattice structure, which is particularly well suited for shape morphing. To achieve shape change, beams are replaced by linear actuators such as those found in pneumatic 4D printing, whose number and placement are optimized to replicate a given target shape. The actuator placement and deformation accuracy are given for four main curvature changes: linear, convex, concave and the transition from one to the other. The results are assessed in terms accuracy of deformation and computational effort. It is shown that the method proposed produces structures that can replicate complex shape changes within 1% of the desired shape. Reducing the number of actuators for robustness purposes is shown to affect the results minimally.
Stylization for Gear Tooth Surfaces With Different Machining Processes Using Graphic Analysis
Authors: Hongu Junichi , Noborio Hiroki , Koide Takao , Tamura Atsutaka
Published: November 2019

This study proposes a stylization method for gear tooth surface using slices of 2-dimensional spectrum. Focusing on a contour (or a slice in the z direction) of the curved surface generated by the 2-dimensinal spectrum, we could approximate the contour to a closed curve, and obtain the ‘scale’ parameter and the ‘shape’ parameter such as a radius, an aspect ratio, etc. which form the closed curve. To determine the flexibility of the proposed method for stylizing the surface texture of gear, this paper shows the approximating the 2-dimensional spectrums which are obtained by frequency analysis of the surface textures of gears with different machining processes using closed curve. As a result of the template matching using astroid, it was found that the astroid can approximate the contour of the 2-dimensinal power spectrum of the gear tooth surface with five machining processes, hob, generation grinding, form grinding, hone and barrel.
Measuring and Optimizing Design Variety Using Herfindahl Index
Authors: Ahmed Faez , Ramachandran Sharath Kumar , Fuge Mark , Hunter Sam , Miller Scarlett
Published: November 2019

In this paper, we propose a new design variety metric based on the Herfindahl index. We also propose a practical procedure for comparing variety metrics via the construction of ground truth datasets from pairwise comparisons by experts. Using two new datasets, we show that this new variety measure aligns with human ratings more than some existing and commonly used tree-based metrics. This metric also has three main advantages over existing metrics: a) It is a super-modular function, which enables us to optimize design variety using a polynomial time greedy algorithm. b) The parametric nature of this metric allows us to fit the metric to better represent variety for new domains. c) It has higher sensitivity in distinguishing between variety of sets of randomly selected designs than existing methods. Overall, our results shed light on some qualities that good design variety metrics should possess and the non-trivial challenges associated with collecting the data needed to measure those qualities.
Optimal Camera Configuration for 3D Scanning of Human Hand
Authors: Yang Yusheng , Elkhuizen Willemijn S. , Hou Tao , Essers Tessa T. W. , Song Yu
Published: November 2019

Fast, accurate and low-cost 3D scans are the key in designing personalized products. In this paper, using close-range photogrammetry technique, we aim at finding the “just enough” number of cameras and their spatial configurations for a full 3D reconstruction of the human hand. Given an object, we establish a mathematical model to describe the 3D constructible ratio based on the field of the view and the depth of field of each camera, as well as the visibility of each part of the object in the view of each camera. Furthermore, we introduce spatial constrains to arrange cameras along two rings for: 1) solving the problem of the large number of parameters in the unconstrained optimization, and 2) the feasibility and flexibility in the construction. Based on the found number of cameras and the spatial configuration of each camera, a prototype scanner was built to verify the effectiveness of the proposed method. The mean absolute error between the 3D scan of a 3D printed hand and its original CAD model was found to be 0.38mm, which is smaller than that (0.52mm) of using the conventional setup. Besides, the distribution of errors is smaller as well, which implicates a better full 3D reconstruction of the scanned hand.
Real-Time Optimal Control of the Gearshift Schedule for Dual Clutch Transmissions
Authors: Liu Yonggang , Wan Yougang , Yang Kunyu , Qin Datong , Hu Minghui
Published: November 2019

In order to improve the fuel economy of vehicles equipped with a dual clutch transmission, this paper proposes a real-time gearshift schedule optimization method based on dynamic programming (DP) and future vehicle speed prediction. The global condition information is necessary for DP algorithm, which makes it difficult to be applied to the real-time control of vehicles. Therefore, BP neural network optimized by genetic algorithm (GA-BP) is utilized to predict future speed information in the research, and the results of speed prediction are introduced into DP problem solving process to realize real-time application of DP optimization in gear decision-making. Simulation results on a fuel vehicle with seven-speed dual clutch transmission using different gear decision-making methods under multiple driving cycles are presented. The results indicate that compared with the case of an empirical economy gearshift strategy, additional fuel can be saved. Furthermore, computational effort for the proposed method is little enough, which guarantees the real-time performance of DP gearshift schedule optimization.
Dynamics Simulation and Control Design of Gun Adjustment for Nonlinear Multibody System of Multiple Launch Rocket System
Authors: Miao Yunfei , Wang Guoping , Rui Xiaoting , Tu Tianxiong , Gu Lilin
Published: November 2019

The dynamics simulation of the processing of the gun adjustment for multiple launch rocket system (MLRS) as a complex nonlinear multibody system is studied. Based on the new version of transfer matrix method for multibody system (MSTMM), the nonlinear multibody system dynamics model of MLRS is established, and the overall transfer equation of the nonlinear multibody system is deduced. The launch dynamics simulation of MLRS is carried out by combining the general kinematics equations of rocket and Monte Carlo method, and the simulated results are verified by experiments. On this basis, the control design and dynamics simulation of the gun adjustment of MLRS has been preliminary studied by combing MSTMM with PD control method. The results show that the proposed control method has a good stability and can realize the automatic control of gun adjustment of MLRS quickly and accurately.
Analyzing the Effect of Prestressing Forces on Selective Compliant Mechanisms: A Case Study
Authors: Mauser Kristian , Friese Jan , Hasse Alexander
Published: November 2019

Once it is designed, the stiffness of a compliant mechanism is not intended to be changed in order to adapt to special operation conditions. Nevertheless, various operation tasks e.g. mechanical grippers, would benefit from such a feature. The effect of axial compression forces, however, is well known to reduce the transverse stiffness of beam-like structures. This paper deals with the effect of prestressing forces on compliant mechanisms. For this purpose, a mathematical description for a modal analysis of compliant mechanisms — based on the author’s former publications — is presented first. Building on this and using a compliant mechanism with one desired translational motion as example, the effect of prestressing forces on the desired deformation and its related stiffness value is analyzed using conventional methods which are based on the Bernoulli-Euler beam equation. However, these methods do not usually consider the undesirable deformations of a mechanism. The modal analysis mentioned above is therefore used in order to examine the effect of prestressing forces on both the desired and undesired deformations. In this analysis, two different compliant mechanisms in several load cases are examined.
Investigating Usability of an Innovation Management Decision Aid
Authors: Gendreau Elizabeth , Summers Joshua D. , Benhayoun-Sadafiyine Lamiae , Le Dain Marie-Anne
Published: November 2019

Initial usability testing was used to identify and fix usability concerns within a recently developed absorptive capacity assessment tool. The tool was designed to aid innovation management decision making by helping firms understand their processing of external knowledge within the context of a collaborative innovation network. Part of the recent development of the tool involved the implementation of Simos-Roy-Figueira’s revised method for eliciting subjective importance weights. However, the method, as it was applied within the tool, suffered from poor usability that could not be fully addressed. This paper presents a study on the usability of the tool further by conducting additional think-aloud studies to better understand its nature. Five common attributes of usability (efficiency, effectiveness, satisfaction, learnability, and usefulness) were characterized based on the findings from the think-aloud studies in order to develop a list of recommendations for improving usability. The goal of these recommendations is to help future academic developers of decision aid tools to better consider usability in their own work to maximize the impact and dissemination of their research.
A Novel 1-DOF Deployable Mechanism for Parabolic Cylindrical Surface Approximation
Authors: Xiao Hang , Lu Shengnan , Ding Xilun
Published: November 2019

This paper presents a novel deployable mechanism for approximating the parabolic cylindrical surface. The proposed mechanism, which can deploy and fold synchronously in the radial and axial directions, is constructed by double four-bar linkages and scissor linkages. In the fully deployed configuration, the mechanism can approximate a cylindrical surface. It can also be folded compactly into a bundle. The radial and axial deployable mechanisms are described and their position kinematics are solved. A synchronous mechanism is designed to ensure the synchronous movement of the radial and axial mechanisms. Geometric parameters of the mechanism for approximating a given parabolic cylindrical surface are obtained. The magnification ratio of the designed mechanism is calculated. The best choice of actuator is determined through static-load analysis.
Flash Temperature Analysis Method for Polymer Gears With Consideration of Deviations in Meshing Kinematics
Authors: Cerne Borut , Zorko Damijan , Duhovnik Joze , Tavcar Joze , Zavbi Roman
Published: November 2019

The presented work describes a computational method for carrying out a detailed and thorough examination of the flash temperature rise (i.e. the local ‘instantaneous’ temperature increase on a contact interface, due to frictional effects) present on the tooth flanks of a polymer gear pair, composed of a combination of POM and PA66 thermoplastics, during a given meshing cycle. The method involves a decoupled sequential procedure, where first the mechanical response of the gear teeth during a whole meshing cycle is analyzed using finite element analysis and, subsequently, a semi-analytical thermal analysis procedure is employed, with which the local flash temperature rise under a given tooth-pair contact can be evaluated. The method provides an accurate reproduction of the actual thermo-mechanical processes taking place at the gear teeth contact interfaces and allows for an investigation of the influence of deviations in the gear flank geometry and gear tolerances, while retaining a manageable enough form for application with moderate computational resources.
Dynamic Analysis of the 3-RRPS Metamorphic Parallel Mechanism Based on Instantaneous Screw Axis
Authors: Nurahmi Latifah , Gan Dongming
Published: November 2019

The 3-rRPS metamorphic parallel mechanism can change its configurations thanks to the reconfigurable (rR) joint. The analysis in this paper will focus on one specific configuration where the moving-platform is able to perform 2-dof coupled rotational motions and 1-dof translational motion, which is well-known as 1T2R motion. In this configuration, the mechanism has two types of operation modes, i.e. x0 = 0 and x3 = 0, which have been extensively studied by many researchers. However, the dynamic behaviours of the mechanism in those two operation modes have not been studied. Accordingly, this paper presents the dynamic analysis of the 3-rRPS metamorphic parallel mechanism in both operation modes based on the Instantaneous Screw Axis (ISA). The types of operation mode are initially characterized by means of Euler-Quaternion parameters. The time derivative of transformation matrix is performed in each operation mode and the ISA can be determined. By using the ISA, velocities and accelerations of all points on the moving-platform can be evaluated, which become the foundation of the dynamic analysis in this paper. This approach can be applied to parallel mechanisms having multiple operation modes of different mobility.
Mesh Stiffness Calculation of Spur Gears With Tooth Surface Crack
Authors: Zhang Luke , Shao Yimin
Published: November 2019

Tooth surface crack is an early fault before spalling, which has an important influence on mesh stiffness and vibration characteristics of the gear system. However, the researches on tooth surface crack are limited as scholars pay little attention to this early fault. In this study, an analytical model of spur gears with tooth surface crack is established. Using the potential energy method, the equations for mesh stiffness calculation of spur gears with tooth surface crack are derived. By adopting the proposed model, the influences of tooth surface crack fault on mesh stiffness of gear tooth are studied. The relationship between tooth surface crack and mesh stiffness of gear tooth under different lengths and depths can be further calculated. This study provides a theoretical basis for the diagnosis of early failure of spalling.
Teaching Technical Design Specifications in Product Redesign Processes Using the FBS Model
Authors: Montoya Ivan D. , Rendon-Velez Elizabeth , Gallego-Sanchez Juan A.
Published: November 2019

Establishment of technical design specifications for the re-design of technical systems, which are not derived from customers needs, relies heavily on designers intuition and experience. The very few methods proposed in the literature for the establishment of such technical design specifications hinders the learning process in conceptual design subjects. The objective of this article is to propose a structured method for identification of technical design specifications based on the function-behavior-state (FBS) model applied on redesign tasks. The method is being taught to students on the course of methodical design in order to develop their abilities on the identification of technical specifications without relying on previous knowledge on the system and relying more on detailed observation. This method is based on the observation and identification of the different states taken by the attributes of the entities conforming the system (i.e., flows-function carriers-environment). A small scale preliminary study was conducted in order to validate the initial performance of the proposed method. Eight groups made up of undergraduate mechanical engineering students with basic knowledge in conceptual design were instructed to identify technical design specifications. The redesign task was to create an automated solution for replacing the manual production process at small food manufacturing companies. Four groups of students had to establish the specifications using their experience while the other four groups had to use the proposed method. Initial results showed for the proposed method a 36% increase in the number of identified specifications.
Exploiting Nonlinear Dynamics and Energy Localization to Enhance the Performances of an Electromagnetic Vibration Energy Harvester
Authors: Aouali Kaouthar , Kacem Najib , Bouhaddi Noureddine , Mrabet Elyes , Haddar Mohamed
Published: November 2019

A multimodal electromagnetic vibration energy harvester based on a nonlinear quasi-periodic system is proposed. The multimodal approach and the nonlinearity are implemented in order to improve the output performances of the studied device. The present study investigates a periodic system composed of two weakly coupled magnets and mechanically guided by two elastic beams. The quasi-periodic system is obtained by varying the mass of one of the moving magnets which leads to the vibration energy localization in regions close to the imperfections introduced. This phenomenon is exploited to maximize the harvested energy. The mechanical nonlinearity is introduced by considering large displacements of the beams which is also investigated to maximize the harvested energy and to enlarge the bandwidth of the device. The quasi-periodic system is modeled by two coupled forced Duffing equations, which are solved using finite difference method combined with arc-length continuation method. The obtained results of the mass mistuning are analyzed and discussed in depth. It is shown that the introduction of the nonlinearity and the functionalization of the energy localization phenomenon lead to the enlargement of the bandwidth and the increase of the vibration amplitudes.
Multi-Pulse Chaotic Dynamics of Eccentric Rotating Composite Laminated Circular Cylindrical Shell by Using the Extended Melnikov Method
Authors: Zheng Yan , Zhang Wei , Liu Tao
Published: November 2019

The researches of global bifurcations and chaotic dynamics for high-dimensional nonlinear systems are extremely challenging. In this paper, we study the multi-pulse orbits and chaotic dynamics of an eccentric rotating composite laminated circular cylindrical shell. The four-dimensional averaged equations are obtained by directly using the multiple scales method under the case of the 1:2 internal resonance and principal parametric resonance-1/2 subharmonic resonance. The system is transformed to the averaged equations. From the averaged equation, the theory of normal form is used to find the explicit formulas of normal form. Based on the normal form obtained, the extended Melnikov method is utilized to analyze the multi-pulse global homoclinic bifurcations and chaotic dynamics for the eccentric rotating composite laminated circular cylindrical shell. The analysis of global dynamics indicates that there exist the multi-pulse jumping orbits in the perturbed phase space of the averaged equation. From the averaged equations obtained, the chaotic motions and the Shilnikov type multi-pulse orbits of the eccentric rotating composite laminated circular cylindrical shell are found by using numerical simulation. The results obtained above mean the existence of the chaos for the Smale horseshoe sense for the eccentric rotating composite laminated circular cylindrical shell.
Design of Composite Structures Through Decision Support Problem and Multiscale Design Approach
Authors: Pathan Rizwan Khan , Beemaraj Soban Babu , Salvi Amit , Sharma Gehendra , Allen Janet K. , Mistree Farrokh
Published: November 2019

Composite materials are increasingly being used in load bearing structures due to their high specific stiffness and strength. Designing composite structures involve solving multiple conflicting objectives (e.g weight and deflection) and constraints (e.g failure stress and strain), which is a challenging task. In the absence of an optimal solution, a compromise solution is desired. Concurrent (material selection plus sizing) design approach using Decision Support Problem (DSP) is used to arrive at a compromise solution. In this paper multiscale design approach is proposed, that incorporates the tailoring of material microstructures and sizing to achieve improved compromise solution. The microstructure properties are obtained by using analytical and computational models for various composite materials. These models compute structure-property relations between bulk material properties and their micro-structural constituents. The approach is demonstrated with an example of a sandwich composite cantilever beam subjected to multiple load cases. An efficiency factor (η) is defined to compare the results of concurrent design approach and multiscale design approach.