bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis and Evaluation of Piecewise Linear Systems With Coulomb Friction Using a Hybrid Symbolic-Numeric Computational Method
Authors: Shahhosseini Amir , Tien Meng-Hsuan , D’Souza Kiran 
Published: November 2021

Abstract
A general formulation of piecewise linear systems with discontinuous force elements is provided in this paper. It has been demonstrated that this class of nonlinear systems is of great importance due to their ability to accurately model numerous scientific and engineering phenomena. Additionally, it is shown that this class of nonlinear systems can demonstrate a wide spectrum of nonlinear motions and in fact, the phenomenon of weak chaos is observed in a mechanical assembly for the first time.
Despite such importance, efficient methods for fast and accurate evaluation of piecewise linear systems’ responses are lacking and the methods of the literature are either incompatible, very slow, very inaccurate, or bear a combination of the aforementioned deficiencies. To overcome this shortcoming, a novel symbolic-numeric method is presented in this paper that is able to obtain the analytical response of piecewise linear systems with discontinuous elements in an efficient manner. Contrary to other efficient methods that are based on stationary steady state dynamics, this method will not experience failure upon the occurrence of complex motion and is able to capture the entirety of the dynamics.
Finite Element Analysis and Thick-Panel Clash Behaviour of Steel Fold-Lines
Authors: Shi Quan , Gattas Joseph M. 
Published: November 2021

Abstract
The structural and mechanical behaviours of most origami-inspired or folded structures is strongly dependent upon the mechanical behaviours of their constituent crease lines. Characterisation of the rotational behaviours of the steel hinges is therefore a critical step in the analysis of origami-inspired steel structures. This paper will present a numerical modelling approach for simulating the rotational response of digitally-fabricated steel hinges, over a large rotation range from 0° up to 170°. Numerical response predictions are verified against published experimental results, over a range of sheet thicknesses and fold line parameters. Models are then used to give insight into observed thick-panel clash behaviours and fold-line localised strap mechanics. The developed numerical modelling procedure provides a convenient analysis method for rapid prediction of steel hinge behaviour.
Grooved Cam With a Translating Follower Having an Added Ternary-Roller Intermediate Link
Authors: Hsu Kuan-Lun , Pan Tung-Hsin , Wu Long-Iong 
Published: November 2021

Abstract
The paper presents an analytical approach for designing grooved cam mechanisms with a modified arrangement of the common translating follower. That is, an extraneous intermediate link that has three rollers is added between the cam and the common follower. On the basis of an existing cam mechanism with a common roller follower, an extraneous intermediate link that has three rollers is added between the cam and the common follower. Such a cam mechanism has two set of profile and can creating multiple contact points between the cam and the follower at any instant. The two sets of profiles of such a cam mechanism can serve as the grooved types. Since the follower has three rollers that can simultaneously contact the cam at any instant, it can be positive driven along the guided groove of cam contour. The contact forces and contact stresses of such cam mechanisms are analyzed to illustrate the advantage of spreading force transmission and reducing contact stress of this uncommon follower. The obtained results indicate that the contact stress at the surface of the cam and the follower for such a cam mechanism can be reduced by 34% to 42% in comparison to those of cam mechanism with a common translating roller follower.
The Influence of Team Goal Alignment and Awareness on Human-Centered Design Team Decision-Making Strategy
Authors: Rao Vivek , Krishnan Ananya , Kwon Jieun , Kim Euiyoung , Agogino Alice , Goucher-Lambert Kosa 
Published: November 2021

Abstract
Design team decision-making underpins all activities in the design process. Simultaneously, goal alignment within design teams has been shown to be essential to the success of team activities, including engineering design. However, the relationship between goal alignment and design team decision-making remains unclear. In this exploratory work, we analyze six student design teams’ decision-making strategies underlying 90 selections of design methods over the course of a human-centered design project. We simultaneously examine how well each design team’s goals are aligned in terms of their perception of shared goals and their awareness of team members’ personal goals at the midpoint and end of the design process, along with three other factors underpinning team alignment at the midpoint. We report three preliminary findings about how team goal alignment and goal awareness influence team decision-making strategy that, while lacking consistent significance, invite further research. First, we observe that a decrease in awareness of team members’ personal goals may lead student teams to use a different distribution of decision-making strategies in design than teams whose awareness stays constant or increases. Second, we find that student teams exhibiting lower overall goal alignment scores appear to more frequently use agent-driven decision-making strategies, while student teams with higher overall goal alignment scores appear to more frequently use process-driven decision-making strategies. Third, we find that while student team alignment appears to influence agent- and process-driven strategy selection, its effect on outcome-driven selection is less conclusive. While grounded in student data, these findings provide a starting place for further inquiry into of designerly behavior at the nexus of teaming and design decision-making.
Analysis of Capillary Driven Flows Through Open Microchannels for Biosensing Application
Authors: Patel Hardikkumar , Yan Terry , Shavezipur Mohammad 
Published: November 2021

Abstract
Integrated micro-biosensors and microfluidic systems have been recently used for detection of cells, proteins, and other biomarkers for a wide range of applications. In this work, open micro-channel flows driven by capillary force designed for food safety applications are studied. The micro-channels are used to deliver the nutrients (extracts of different fresh produce) to the sensing site where pathogens reside. The presence of nutrients, simulating the condition that micro-organisms experience in real food materials, allow us to investigate their behavior in real time. Open channels studied in this work are partially covered to allow for etching of the sacrificial layer that creates the channel and use of capillary force to create a self-driven microfluidic system in which fluid flow is actuated by surface tension and wall adhesion. Numerical simulations are used to investigate the fluid flow regime in micro-channels using ANSYS FLUENT. The volume of fraction (VOF) method is used to simulate the dynamics of fluid flow in microchannels made of polycrystalline silicon with a thin layer coating of native silicon dioxide. The effects of channel size and different geometries (open channel, T-junction, and L-junction) on a flow rate of water in the channel are investigated. Our study shows that adding T- and L-junctions to the flow path would create a small delay in the fluid flow in the channel, and the number of junctions directly affect the delay, however, it does not prevent the fluid transfer by capillary force. The (partially covered) open channel geometry presented in this work is compatible with conventional surface micromachining process.
Trajectory Planning for a 3-S

P

S-U Tensegrity Mechanism
Authors: Venkateswaran Swaminath , Chablat Damien 
Published: November 2021

Abstract
This article presents the actuation strategy of a 2-DOF tensegrity type mechanism that employs three tension springs and a passive universal joint. This mechanism is proposed to be incorporated as an articulation unit for a piping inspection robot in order to overcome pipe bends and junctions. In the event of a junction, external actuations are required to allow the mechanism as well as the robot to follow a certain direction. Using DC-motors coupled with encoders, experiments are carried out on a test bench of the tensegrity mechanism. The actuation of the mobile platform is performed using cables that pass through each spring. By correlating the architecture to a 3-SPS-U parallel mechanism, the singularity-free workspace of the mechanism is analyzed to identify the tilt limits. A closed-loop PID controller is implemented using a microcomputer to perform a linear trajectory within the singularity-free workspace. The Inverse Kinematic Problem (IKP) is solved by passing input tilt angles to the controller. With the help of a force control algorithm, the experiments are carried out under no-load conditions for vertical and horizontal orientations of the mechanism. The error data of the joint positions and the motor torques are then interpreted for both orientations of the mechanism.
Nonlinear Control of a Transient Inductrack System Using State Feedback
Authors: Wang Ruiyang , Yang Bingen 
Published: November 2021

Abstract
The concept of Inductrack refers to the magnetic levitation technology achieved by Halbach arrays of permanent magnets. In an Inductrack system, the dynamic behaviors involved with transient responses are difficult to capture due to the highly nonlinear, time-varying, electromagnetic-mechanical couplings. In the literature, dynamic modeling of Inductrack systems that aims to analyze the transient behaviors has been widely addressed. However, one common issue with the previous investigations is that most of the dynamic models either partly or completely adopted certain steady-state and ideal case assumptions. These assumptions are extremely difficult to maintain in a transient scenario, if not impossible. Therefore, while providing good understanding of Inductrack systems, the previous results in dynamic modeling have a limited utility in providing guidance for feedback control of Inductrack systems.
Recently, a benchmark transient Inductrack model was created for characterizing the transient time response of the system with fidelity, which enables model-based feedback control design. In this work, based on the transient model, a new control method for the Inductrack dynamic system is developed. The proposed control method consists of a linear part and a nonlinear part. The linear part is devised based on a state feedback configuration; the nonlinear part is accomplished by fitting a nonlinear “force-current” mapping function. With this nonlinear feedback controller, the levitation gap of the Inductrack vehicle can be effectively stabilized at both constant and time-dependent traveling speed. The proposed control law is demonstrated in numerical examples. The nonlinear control design is potentially extensible to more complicated Inductrack systems with higher degrees of freedom.
Towards Transparent Motion Planning of Wearable Rehabilitation Exoskeletons via Model-Based Estimation
Authors: Wang Jiamin , Blankenship David , Barry Oumar 
Published: November 2021

Abstract
We propose a novel online model-based motion planning algorithm for a family of rehabilitation exoskeletons to improve transparency in user-guided operation. In this study, we assume that the short-term human movement intention can be embedded in the time-delay dimensions of motion signals. The model-based estimation is employed to obtain the interaction load between the dynamical subsystems respectively controlled by the human and exoskeleton. The objective of the proposed motion planning algorithm is to reduce the interaction load, which leads to the establishment of a least-square optimization problem. A Support Vector Regression (SVR) model, driven by the time-delayed motion data, is implemented to solve the optimization problem by generating the acceleration of tracking reference. The motion planning algorithm based on SVR can be combined with a variety of trajectory tracking controllers. To ensure the efficiency of the algorithm for online applications, we also design the SVR model so that its properties can be calculated recursively based on latest data sets. The performance and characteristics of the motion planning algorithm are then observed and discussed through the control simulations of a wearable wrist exoskeleton designed for pathological tremor alleviation. The results show that while the planned tracking reference can approximate the synthetic human movement intention, the motion planning accuracy can be limited by system disturbances, and the delay of signals caused by digital filters.
Design of Stackable Origami Structures With Elastic Deployment Capabilities
Authors: Ma Peiwen J. , Verniani Alessandro , Peraza Hernandez Edwin A. 
Published: November 2021

Abstract
This work presents a flexible type of origami structure that may be elastically deployed from a compact stacked form to a freeform target shape. The design process enables a target surface mesh to be converted into a compact stacked structure that may be deployed through the release of elastic energy stored in the folds. The process begins by finding a non-branching path passing once through each face in the target mesh. The edges of the target mesh not included in the path are cut and elastic smooth folds are introduced along those crossed by the path. The introduced smooth folds are folded in a sequence of ±180° along the path to create a stack. The structure transforms from the stacked form towards the target shape through the release of the stored elastic energy generated during stacking. The design framework considers the strain energy needed to sustain transformation and the required sizing of the smooth folds. The resemblance of the designed target shape with smooth folds compared to the target mesh is studied, and the significant volume saving when the structure is stowed in the stacked form is quantified. Examples showing the application of the design process to a diverse set of target meshes are provided. Proof-of-concept prototype fabrication using a 3D printer demonstrates the feasibility of the design approach. The results reflect the benefits of deployable stacked origami structures and show volumetric space savings from 50% to 90% while preserving around 80% of the target mesh area after the elastic smooth folds are introduced.
Data-Driven Customer Segmentation Based On Online Review Analysis and Customer Network Construction
Authors: Park Seyoung , Kim Harrison M. 
Published: November 2021

Abstract
Recently, many studies on product design have utilized online data for customer analysis. However, most of them treat online customers as a group of people with the same preferences while customer segmentation is a key strategy in conventional market analysis. To supplement this gap, this paper proposes a new methodology for online customer segmentation. First, customer attributes are extracted from online customer reviews. Then, a customer network is constructed based on the extracted attributes. Finally, the network is partitioned by modularity clustering and the resulting clusters are analyzed by topic frequency. The methodology is implemented to a smartphone review data. The result shows that online customers have different preferences as offline customers do, and they can be divided into separate groups with different tendencies for product features. This can help product designers to draw segment-based design implications from online data.
High-Dimensional Reliability Method Accounting for Important and Unimportant Input Variables
Authors: Yin Jianhua , Du Xiaoping 
Published: November 2021

Abstract
Reliability analysis is usually a core element in engineering design, during which reliability is predicted with physical models (limit-state functions). Reliability analysis becomes computationally expensive when the dimensionality of input random variables is high. This work develops a high dimensional reliability analysis method by a new dimension reduction strategy so that the contributions of both important and unimportant input variables are accommodated by the proposed dimension reduction method. The consideration of the contributions of unimportant input variables can certainly improve the accuracy of the reliability prediction, especially where many unimportant input variables are involved. The dimension reduction is performed with the first iteration of the first order reliability method (FORM), which identifies important and unimportant input variables. Then a higher order reliability analysis, such as the second order reliability analysis and metamodeling method, is performed in the reduced space of only important input variables. The reliability obtained in the reduced space is then integrated with the contributions of unimportant input variables, resulting in the final reliability prediction that accounts for both types of input variables. Consequently, the new reliability method is more accurate than the traditional method, which fixes unimportant input variables at their means. The accuracy is demonstrated by three examples.
Method for Generating Mechanical Linkages of Polygons That Fold Into a Similar Shape
Authors: Yamamoto Yohei , Mitani Jun 
Published: November 2021

Abstract
Origami techniques, as folding and unfolding, can be utilized in shrinkable structures. Especially when the crease pattern is rigid foldable, it can be treated as a mechanical linkage of rigid panels connected by hinges. Since rigid foldable crease patterns have the strong geometrical constraint of the facets not being able to stretch or bend, it is difficult to design new crease patterns, and variations of existing patterns are limited. However, it is known that there are cases where crease patterns can be made rigid foldable by adding some slits. This paper proposes a mechanical linkage that folds into a similar flat shape by adding slits. A method is presented of generating rigid foldable crease patterns in arbitrary polygons that fold smaller, and it is confirmed that structures that have a mechanism for shrinking can be generated from these crease patterns by using rigid thick panels and hinges.
Design of a Self Balancing Vehicle as a Test Rig for Safety Control Strategies Investigations
Authors: Righettini Paolo , Strada Roberto , Santinelli Jasmine 
Published: November 2021

Abstract
The present paper is related to a research activity concerning self-balancing vehicles, with particular reference to the interaction between driver and vehicle’s dynamics, at the aim to investigate safety management and strategies. In particular, the paper presents the design process of a self-balancing vehicle with the target to be used as a test rig for safety investigations. Besides the definition of the mechanical configuration, the design process includes also the choice of the motor/transmission unit, the design of the control system and the design of sensors related to vehicle/driver interaction. For design purposes, a simplified two dof planar model has been considered with the driver fixed with the vehicle chassis. Through a proper linearisation of such model, the dynamics of the system has been described by means of a state space approach, used to tune the controller, not only for stability but also for optimal response. In order to test the suitability of the designed vehicle for safety investigations, the paper presents also a Multibody model of the vehicle designed and of a driver with three driven joints. Such model allows to simulate the interaction between human (driver) and machine (vehicle), taking into consideration also the coupling between longitudinal motion and turn. By means of co-simulations between the multibody model (developed with MSC.Adams) and the controller (modelled with Matlab/Simulink), tests have been performed showing the possibility to detect influence of the driver’s behavior on the vehicle’s dynamics.
Stochastically-Trained Physics-Informed Neural Networks: Application to Thermal Analysis in Metal Laser Powder Bed Fusion
Authors: Pierce Justin , Williams Glen , Simpson Timothy W. , Meisel Nicholas A. , McComb Christopher 
Published: November 2021

Abstract
Modern digital manufacturing processes, such as additive manufacturing, are cyber-physical in nature and utilize complex, process-specific simulations for both design and manufacturing. Although computational simulations can be used to optimize these complex processes, they can take hours or days — an unreasonable cost for engineering teams leveraging iterative design processes. Hence, more rapid computational methods are necessary in areas where computation time presents a limiting factor. When existing data from historical examples is plentiful and reliable, supervised machine learning can be used to create surrogate models that can be evaluated orders of magnitude more rapidly than comparable finite element approaches. However, for applications that necessitate computationally-intensive simulations, even generating the training data necessary to train a supervised machine learning model can pose a significant barrier. Unsupervised methods, such as physics-informed neural networks, offer a shortcut in cases where training data is scarce or prohibitive. These novel neural networks are trained without the use of potentially expensive labels. Instead, physical principles are encoded directly into the loss function. This method substantially reduces the time required to develop a training dataset, while still achieving the evaluation speed that is typical of supervised machine learning surrogate models. We propose a new method for stochastically training and testing a convolutional physics-informed neural network using the transient 3D heat equation- to model temperature throughout a solid object over time. We demonstrate this approach by applying it to a transient thermal analysis model of the powder bed fusion manufacturing process.
A Model for the Digital Method of Measuring LED Incident Photocurrent
Authors: Campbell Jake , Pretty Christopher G. , Knopp Jennifer , Bones Phil , Chase J. Geoffery 
Published: November 2021

Abstract
Pulse oximeters and other light based sensor types are used to monitor arterial blood oxygen levels, heart rate, and much more that rely on LEDs and photodiodes. The conventional method of using photodiodes to detect light signals is accurate, but requires relatively expensive hardware processing to extract the signal. Digital sensing of light using an LED provides a low-cost alternative by using a voltage threshold timing method. However, the accuracy of this method is dependant on the microcontroller clock speed and suffers from variable sample rate (100 us to 10 ms). This paper develops a model for a digital light sensing method using only a microcontroller’s ADC and timer, and an LED. Using the voltage discharge curve of a reverse biased LED, the sensor is capable of accurately detecting light intensities ranging from 0–3885 mcd at a sample period of 500 us. A linear relationship was found through the incident light intensity ranges of 0 to 3880 mcd. The model fit the expected experimental values, with an estimated photocurrent ranging from 10 pA to 55 nA. With an R2 of 0.9997, the model demonstrates the digital sensing method linearly responds to incident light intensity and can simplify the design of pulse oximeters and similar light based sensor types.