bluuebunny/crossref_metadata_2025 huggingface dataset:
Discovery of Customized Dispatching Rule for Single-Machine Production Scheduling Using Deep Reinforcement Learning
Authors: Chua Ping Chong , Moon Seung Ki , Ng Yen Ting , Ng Huey Yuen , Lopez Manel
Published: November 2022

A dispatching rule has become one of the most widely used approaches in producing scheduling due to its low time complexities and the ability to respond to dynamic changes in production. However, there is no one dispatching rule that dominates the others for the performance measure of interest. By modelling the selection of a dispatching rule to transit from one production state to another using a Markov decision process, current methods involving reinforcement learning make use of a predefined list of dispatching rules, which may limit the optimization of a specified performance measure. Greater flexibility can be achieved by creating customized dispatching rules through the important selection of production parameters for the performance measure in question. Using parameters obtained readily within the digital twin setting, this paper investigates the application of deep reinforcement learning to select customized dispatching rules formed by weighted combinations of production parameters on a single machine production scheduling problem. Due to the curse of dimensionality of storing Q values for all possible production states in a Q-table, a deep Q network is trained for the dynamic selection of the customized dispatching rules. Preliminary results show its effectiveness in minimizing total tardiness and outperform well-known existing dispatching rules.
Nonlinear Oscillations in Delayed Collocated Control of Pendulum on Trolley
Authors: Szaksz Bence Mate , Stepan Gabor
Published: November 2022

The paper investigates the nonlinear dynamics of the collocated position control of a trolley that carries a pendulum. Delayed proportional derivative control force is considered, which is based on the position and velocity of the trolley only. Stability charts are constructed for different parameter combinations, which show intricate structures in the plane of the control parameters. To examine the nonlinear behaviour of the system, the Hopf bifurcation calculation is carried out after an infinite dimensional center manifold reduction. This indicates that supercritical Hopf bifurcations always exist at the boundary of the first stable lobe, however, for increasing time delays, the reappearing stable lobes may be bounded with subcritical Hopf bifurcations as well, and even quasi-periodic oscillations may occur.
Carbon/PEEK/Zirconia Hybrid Composite for High-Performance Applications
Authors: Pagano Claudia , Basile Vito , Surace Rossella , Terzi Roberto , Schioppa Monica , Palazzo Barbara , Fassi Irene
Published: November 2022

Hybrid polymer composites are very promising for applications in a wide variety of sectors, such as automotive, aerospace, robotics, energy and construction. These materials consist of a polymer matrix and two or more fillers, which synergically interact resulting in enhanced specific properties and performance. Among hybrid polymer composites, those based on carbon fibers reinforced poly(ether ether ketone) (C-PEEK) are gaining a primary role for their excellent mechanical and chemical properties; zirconium oxide (ZrO2) nanoparticles can further enhance these properties, improving also the wear resistance. In this paper, a new hybrid C-PEEK+ZrO2 composite has been studied and its mechanical properties compared with its reference composite C-PEEK.
Comparison of Multi-Objective Optimisation Methods for the Design of Electric Motors
Authors: Barri Dario , Soresini Federico , Gobbi Massimiliano , Mastinu Gianpiero
Published: November 2022

The paper deals with a comparison between different multi-objective optimisation algorithms, namely Adaptive Pareto Algorithm (APA), Genetic Algorithm (GA) and Parameter Space Investigation (PSI). The comparison has been completed by solving a test problem (ZDT1) widely considered in the literature and a real engineering problem concerning the optimisation of traction electric motors. The practical problem is addressed with the help of a specific custom-made tool for the optimisation of electric motors, where Motor-CAD™ is used as multi-physics simulation software. Several metrics have been defined to objectively characterize the Pareto-optimal solutions obtained with the different algorithms.
Design and Modeling of a Biomimetic Robotic Wrist via Hybrid Mechanism
Authors: El Kihal Mohammed , Wang Jiamin , Barry Oumar
Published: November 2022

The wrist is critical to people’s activities of daily living, which consists of two major degrees of freedom (DOF) — flexion-extension (FE) and radial-ulnar-deviation (RUD). This paper proposes a novel 2-DOF biomimetic robotic wrist design for a forearm mannequin, which is developed as a safe test bench that emulates human forearm movements for exoskeleton experimentation. Due to the complexity of the coupled motions of FE and RUD, existing robotic wrists mainly focus on the FE motion, and sometimes incorporate the forearm pronation/supination instead of the RUD motion. To solve this issue, the robotic wrist features a simple but effective hybrid mechanism for FE and RUD motions, which avoids the axes offset between FE and RUD from producing unnatural wrist movements and allows ranges of motions comparable to those in a human wrist. We analyze the kinematics of the hybrid wrist mechanism, which leads to the establishment of the dynamical model through a generic constrained multibody formulation. A robust controller is then adopted for reference trajectory tracking control. We then perform numerical simulations, which validate the control performance and actuator choice, and evaluate the workspace, rotation axes offset, and inertial characteristics. The results preliminarily verify the biomimetic robotic wrist as a feasible solution for the forearm mannequin to realize natural wrist movement emulation.
Frequency-Amplitude Response of Parametric Resonance of Electrostatically Actuated MEMS Cantilever Beams Driven by Fringe Effect
Authors: Martinez Miguel A. , Caruntu Dumitru I.
Published: November 2022

This work deals with the frequency-amplitude response of parametric resonance of electrostatically actuated micro-electro-mechanical-system (MEMS) cantilever beam resonators driven by the fringe effect. The system involves a flexible MEMS cantilever beam parallel to a ground plate. The electrostatic force induced is due to the electric field between the cantilever beam and the ground plate (volume between cantilever and ground plate) and the electric field outside this volume which leads to the fringe effect. In this work, the cantilever is driven only by the fringe effect. The electrostatic force due to the electric field within the volume between cantilever and ground plate is neglected due to hole in the ground plate (size of cantilever). Excitations due to the fringe effect near the natural frequency of the MEMS cantilever beam lead the MEMS cantilever resonator into parametric resonance. The partial differential equation describing the motion of the cantilever resonator is nondimensionalized and a reduced order model is developed. This is a one-mode of vibration model which is solved using the Method of Multiple Scales (MMS). The frequency-amplitude response (bifurcation diagram) is predicted. The fringe effect was modeled by neglecting the electrostatic force term, and keeping the first four terms of the Taylor polynomial of the fringe effect (small terms due to small bookkeeping parameter). The method shows a zero-amplitude steady-state stable branch (trivial solution) for the entire range of resonant frequencies. In addition, two branches, one stable and one unstable, with two bifurcation points, subcritical and supercritical, are predicted. The response due to the fringe effect is compared to responses that involve the electrostatic force only as well as electrostatic and fringe combined. The influence of damping and voltage on the frequency-amplitude response are also investigated. As the damping increases, both non-zero steady-state branches, are shifted to higher frequencies and larger amplitudes. On the other hand, as the voltage increases the two non-zero branches are shifted to lower frequencies and smaller amplitudes.
Using Compliant Implants to Reduce Post-Operative Pain in Pectus Excavatum Correction
Authors: Roubicek Clark , Sargent Brandon , Garcia Victor , Howell Larry
Published: November 2022

In this work, we propose a medical device to be used for correcting pectus excavatum. Pectus excavatum is the most common chest wall deformity, resulting in exercise intolerance, shortness of breath, and chest pain. The current correction method uses a rigid bar that causes moderate to severe pain in patients. The device presented in this paper (termed the Elastic Bar) utilizes the phenomenon seen in pectus carinatum patients in which the patient’s chest wall becomes less stiff after a force is applied for an extended period of time; the device leverages this phenomenon to create gradual correction of the deformity. The elastic bar is a compliant solution to pectus excavatum. We present a set of requirements that determine the success of the compliant solution to correcting pectus excavatum. To analyze the performance of the device against these requirements, two models are developed, one using a fixed-guided modeling approach and the other using an initially curved beam modeling approach. We then use analytical models (developed following the Pseudo-Rigid-Body modeling technique), finite element analysis simulations, and a physical prototype to verify the feasibility of this new device. We find that the three different verification methods agree within approximately 10%. We conclude that this device has the potential to provide improved care to patients with pectus excavatum.
Experimental Analysis of Flexural-Torsional Forced Vibrations of A Piezoelectric Double-Cantilever
Authors: Zargarani Anahita , O’Donnell John , Mahmoodi S. Nima
Published: November 2022

In this paper, the experimental flexural-torsional forced vibration of a piezoelectric double-cantilever structure is studied and compared with analytical results. The structure of interest consists of two uniform and identical Euler-Bernoulli cantilever beams that are connected by a rigid tip connection at their free ends. Each of the cantilever beams can be excited by a piezoelectric layer attached on its top surface. The time response to the forced vibrations of the structure induced by the piezoelectric actuators is found using the Galerkin approximation method. The effects of dimensional parameters, the length of the cantilever beams and the length of the tip connection, as well as the piezoelectric input voltage on the flexural-torsional amplitude of the vibrations of the structure are studied analytically and experimentally. The amplitude of the flexural-torsional vibrations of the structure is observed to be proportional to the piezoelectric input voltage. However, the slope of the curves defining this relationship depends on dimensional parameters. For a constant input voltage, the effect of either of the dimensional parameters on the amplitude of vibrations is dependent on the other dimensional parameter such that a turning point, whose location is dependent on the configuration of the structure, exists in all the curves.
The Cognitive Costs of Design Tasks: The Evolution of Cognitive Load in Design and Its Relationship With Design Outcomes
Authors: Calpin Nicole , Menold Jessica
Published: November 2022

Problem solving can be a cognitively intensive undertaking; as design is characterized by ambiguity and unknowns, design problems in particular can be cognitively expensive. Few studies examine the evolution of cognitive load during the engineering design process and the linkages between sub-dimensions of cognitive load and design task outcomes. To address this issue, the goal of this work is to establish a relationship between cognitive load, design task, and design outcomes. Twenty participants were recruited to perform a design task where their mental workload was recorded at each stage of the design process. Their ideation and prototype outcomes were then evaluated to determine if there is a relationship between cognitive load, design task, and design outcomes. Results suggest that there is a significant difference in cognitive load experienced by the designer during each stage of the design process and while cognitive load is correlated with idea generation design outcomes, it may not be tied to prototyping design outcomes.
Applications of Origami Principles in Deployable Childcare Furniture
Authors: Ames Daniel C. , Mittelman Aliya , Jones Jaxon , Halverson Denise , Bateman Terri , Magleby Spencer P. , Howell Larry L.
Published: November 2022

Design projects in childcare settings present unique design challenges because of their function, size, and specific safety concerns. In selecting effective childcare furniture, stowage space, safety, and ease of access for childcare furniture are important considerations. Origami-inspired design can be useful in addressing these issues in an innovative way by introducing flat-foldability and deployability into childcare furniture. Fundamental design considerations for childcare furniture and mechanical design principles for deployable furniture are examined in order to understand how to make safe and functional furniture pieces. Childcare furniture must be very child-safe. This means that origami principles used must not add safety concerns like decreased stability or pinch points. Nonhazardous, durable, and comfortable materials must be used. Extra precaution must be taken when designing folding structures for use in a childcare environment. Mechanical principles for such systems, including folding methods and thickness accommodation, are examined in the context of childcare spaces. Various types of joints are also examined and the M-LET compliant joint is shown as a potential replacement for rigid hinges in folding furniture. Using this understanding, this work presents two simple flat-folding techniques and a compliant joint suitable for a childcare setting and demonstrates these principles through functional “safe space” furniture.
DTM Past, Present, and Future: Reflections on and by the Design Theory and Methodology Research Community
Authors: Toh Christine , Cagan Jonathan , Fu Kate , McAdams Dan A. , McComb Christopher , Seering Warren , Thurston Deborah , Wood Kristin
Published: November 2022

This paper describes the results of an agenda-setting panel session that took place at the 2021 International Design Engineering Technical Conferences organized by the Design Theory and Methodology (DTM) research community. While the state of design research in engineering design has advanced tremendously in the last thirty-five years since the formation of the DTM community, reflecting on the successes and challenges faced by this community revealed several key directions and opportunities that this community is well positioned to take. Namely, panelists and audience members in the session identified five new agenda items that have the potential to further strengthen research on Design Theory and Methodology: 1) Ethics, Equity, and Justice-focused design research, 2) Design for Sustainability research programs, and 3) Research on Computational Agents as team members in the design process,4) Building new theories from research conducted on Design Theory and Methodology, and 5) Focus on inclusive excellence in the review process of new and cross-disciplinary research. These agenda items as well as reflections on the history and legacy of the Design Theory and Methodology research community on the evolution of design research more broadly are discussed in this paper. The results of the panel session provide directions for next-generation design theory and methodology research that is effective, inclusive, and impactful.
Topological Properties and Localized Vibration Modes in Quasiperiodic Metamaterials With Electromechanical Local Resonators
Authors: LeGrande Joshua , Bukhari Mohammad , Barry Oumar
Published: November 2022

Simultaneous energy harvesting and vibration attenuation has been a topic of great interest in many recent investigations in mechanical metamaterials. These studies have shown the ability to harvest electrical power using weak electromechanical coupling in periodic metamaterials with no effect on the material’s bandgap boundaries. However, the effect of the electromechanical resonator on the topological properties (i.e. the bandgap topology) and localized mode shapes of a quasiperiodic metamaterial has not yet been determined. In this paper, we study a quasiperiodic metamaterial coupled to electromechanical resonators to observe its bandgaps and localized vibration modes. We show here the analytical dispersion surfaces of an infinite quasiperiodic metamaterial with electromechanical local resonators. The natural frequencies of a semi-infinite system are also simulated numerically to validate the analytical results and show the band structure for different quasiperiodic patterns, load resistors, and electromechanical coupling coefficients. Furthermore, the mode shapes are presented here for a semi-infinite structure showing localized vibration within the bandgaps. The results demonstrate that quasiperiodic metamaterials with electromechanical local resonators can be used to harvest energy without changing the topology of the bandgaps for the case of weak electromechanical coupling. The observations given here can be used to guide designers in choosing electromechanical resonator parameters and quasiperiodic pattern parameters for an effective energy harvesting metamaterial.
Am I Right? Investigating the Influence of Trait Empathy and Attitudes Towards Sustainability on the Accuracy of Concept Evaluations in Sustainable Design
Authors: Alzayed Mohammad Alsager , Starkey Elizabeth M. , Ritter Sarah C. , Prabhu Rohan
Published: November 2022

Concept selection is an integral stage in the design process, in which designers evaluate and compare solutions to select a smaller subset of solutions for further development. In this stage, designers often rely on their self-evaluations of solutions — either independently or using design tools — to make design decisions. However, the reliance on self-evaluations among novice designers could lead to faulty decision-making, given the presence of numerous cognitive biases. Consequently, we aim to investigate the accuracy of novice designers’ self-evaluations of the sustainability of their solutions and the moderating role of (1) trait empathy and (2) their beliefs, attitudes, and intentions towards sustainability on this accuracy. Towards this aim, we conducted an experiment with first-year engineering students comprising a sustainable design lecture and a design activity. At the end of the design activity, participants were asked to evaluate the sustainability of their own solutions and these self-evaluations were compared against expert evaluations. From the results, we see that participants demonstrate some degree of accuracy in their self-evaluations, but only with the sustainable design heuristics of longevity, sharing for maximal use, and active repair of misuse. Second, we see that trait empathy moderated the accuracy of self-evaluations, with participants reporting lower levels of fantasy and empathic concern demonstrating more accurate self-evaluations. Finally, we see that beliefs, attitudes, and intentions towards sustainability also moderated the accuracy of their self-evaluations, and participants with lower levels demonstrated greater accuracy of self-evaluations. Taken together, these findings suggest that designers’ individual differences such as trait empathy could moderate the accuracy of the evaluation of their solutions, especially in the context of sustainability.
A Preliminary Approach to Select an Origami Source Pattern for Deployable Space Arrays
Authors: Bolanos Diana , Ynchausti Collin , Magleby Spencer P.
Published: November 2022

This paper presents a systematic approach for selecting an origami source pattern for deployable space array applications, followed by two case studies used to demonstrate the selection process. Applying origami principles to form engineering solutions can be a difficult task. Competing requirements may create confusion around which pattern is most favorable for the space array application. As a result, this paper aims to provide clarity on the process needed to effectively design an origami space array. The focus of this paper is to provide aerospace engineers and designers with a framework for identifying optimal origami source patterns for space array applications.
Now Is the Time! Exploring the Effects of Variations in the Timing of a Sustainable Design Educational Intervention
Authors: Alzayed Mohammad Alsager , Starkey Elizabeth , Prabhu Rohan
Published: November 2022

The accelerating depletion of natural resources has brought sustainability to the forefront and therefore, design educators must integrate sustainability into the engineering design curriculum. Several researchers have proposed educational interventions and design tools for sustainable design education. The timing of introducing such interventions, particularly in project-based courses, could influence the effectiveness of these interventions, and these effects remain largely unexplored. Our aim in this research is to investigate this research gap through a mixed-methods experiment conducted with first-year engineering design students. Specifically, we introduced a two-day module on sustainable design either in the first or sixth week of an 8-week long design project. The effects of this variation were compared by analyzing (1) changes in students’ trait empathy, (2) changes in their beliefs, attitudes, and intentions towards sustainability, and (3) their responses to a reflection assignment collected at the end of the semester/design project. From the results, we see that the timing of the sustainable design intervention did not influence changes in students’ trait empathy or their beliefs, attitudes, and intentions towards sustainability. However, students from both timing conditions reported significant increases in their attitudes and intentions towards sustainable action. Finally, students who received the intervention earlier more frequently mentioned the use of sustainable design heuristics in their reflection responses. Taken together, these findings suggest the need for educators to consider the timing of sustainable design interventions, especially when integrating them into longer project-based courses.
Concurrent Build Direction, Part Segmentation, and Topology Optimization for Additive Manufacturing Using Neural Networks
Authors: Chen Hongrui , Whitefoot Kate S. , Kara Levent Burak
Published: November 2022

We propose a neural network-based approach to topology optimization that aims to reduce the use of support structures in additive manufacturing. Our approach uses a network architecture that allows the simultaneous determination of an optimized: (1) part segmentation, (2) the topology of each part, and (3) the build direction of each part that collectively minimize the amount of support structure. Through training, the network learns a material density and segment classification in the continuous 3D space. Given a problem domain with prescribed load and displacement boundary conditions, the neural network takes as input 3D coordinates of the voxelized domain as training samples and outputs a continuous density field. Since the neural network for topology optimization learns the density distribution field, analytical solutions to the density gradient can be obtained from the input-output relationship of the neural network. We demonstrate our approach on several compliance minimization problems with volume fraction constraints, where support volume minimization is added as an additional criterion to the objective function. We show that simultaneous optimization of part segmentation along with the topology and print angle optimization further reduces the support structure, compared to a combined print angle and topology optimization without segmentation.
Multi-Mission Engineering With Zero Trust: A Modeling Methodology and Application to Contested Offshore Wind Farms
Authors: Van Bossuyt Douglas L. , Hale Britta , Arlitt Ryan M. , Papakonstantinou Nikolaos
Published: November 2022

With the growth of autonomy and augmentation of machine learning in system decision-making, systems-of-systems (SoS) have become increasingly complex. Security and safety, as well as national economic stability, are reliant on interconnected systems with multiple decision making components. While such inter-connectivity advances the speed at which action and mission control decision making can take place, it also increases the number of dependencies at risk in the case of an attack and the speed at which attacks become effective in their goals. Attacks on the supply chain and on system lifecycle phases other than the operation are also becoming more common. In this paper we consider from a mission engineering perspective a complex reconfigurable SoS covering management of a wind farm with autonomous uncrewed patrol systems, crewed maintenance vessels, back-end control and machine learning components. The complex SoS is situated in the exclusive economic zone of one country, but with perimetric position to regional power competitors. We investigate causal effects of adversarial capabilities in the case study, using a zero trust combined with Defense in Depth approach. Of particular interest are situations where an adversary injects an incipient fault during one mission that is only brought to fruition during a subsequent mission.
Design and Simulation of a MEMS Capacitive Pressure Sensor With Corrugated Membrane and Linear Capacitance-Pressure Response
Authors: Shavezipur Mohammad
Published: November 2022

This paper presents a new design for MEMS capacitive pressure sensor that helps to linearize the capacitance-pressures response of the sensor. Capacitive pressure sensors have two electrodes, one often fixed and one is deformed as the ambient pressure changes. In general, the two electrodes are made of flat thin films. The proposed sensor design is based on a corrugated membrane, where circular ridges and grooves are made in the membrane altering its deformation as the pressure is applied. The sensor design is analyzed using finite element simulations, and ANSYS coupled-field multiphysics solver is used to model and obtain the response of a conventional and corrugated pressure sensor as the ambient pressure changes. The simulation results show that, as expected, the sensor displays high sensitivity at lower pressure and as the pressure increases and the contact area between the membrane and fixed electrode expands, the sensitivity of the capacitance-pressure (C-P) response decreases for both sensors. However, the sensor with corrugated membrane displays high linearity at lower pressures. The response for proposed design at this pressure range is nearly a perfect line, while the conventional design exhibits nonlinearity that is visually noticeable. To quantitatively evaluate the level of linearity of the C-P responses, a linearity factor as the coefficient of linear correlation between the capacitance and pressure is used. The simulation results show that at low pressure of 0.2–1.0 MPa, the sensor with corrugated membrane has high linearity of 0.999 compared to 0.987 for conventional sensor, where for pressure range 0–1.0 MPa these values are 0.997 and 0.983, respectively. The quantitative comparison of the linearity factors for the two design show a notable improvement in the linearity of the C-P response providing nearly a constant sensitivity over the pressure range of 0.2 to 1.0 MPa.
An Empirical Study of the Impact of Task Expectation Framing on Design Decision Delegation
Authors: Malak Richard , Smallman Rachel , Lench Heather
Published: November 2022

The delegation of decision authority is a routine part of engineering systems design. Examples include hiring an outside subcontractor and assigning specific design tasks to a subordinate engineer. In all cases, the delegator is responsible for describing the task to the delegate in a way that clarifies expected outcomes. Ideally, the delegate executes the task in a manner consistent with the preferences of the delegator. For systems design tasks, this means the delegate specifies an artifact with engineering attributes desired by the delegator. Whether such expectations are conveyed successfully can have a major impact on the success of a project. However, despite the central nature of such communications in engineering systems design and the potential consequences miscommunication, there has been little empirical investigation of decision delegation in design. This experimental study examines how the framing of decision task expectations impact task outcomes. Subjects participate in an engineering-themed computer game in which they make design choices. Subjects are assigned to conditions randomly, with some given instructions framed as traditional design requirements and others given instructions in a value-driven design framing (e.g., to maximize a figure of merit). A total of 472 engineering students participated in the study. Results indicate that task outcome expectation framing can impact task performance, with design requirement task framings exhibiting advantages over a value-driven framing. This suggests theoretical arguments favoring value-driven framings may not capture adequately the effect of human behavior.
Multi-Fidelity Reduced-Order Models for Multiscale Damage Analyses With Automatic Calibration
Authors: Deng Shiguang , Mora Carlos , Apelian Diran , Bostanabad Ramin
Published: November 2022

Predicting the fracture behavior of macroscale components containing microscopic porosity relies on multiscale damage models which typically ignore the manufacturing-induced spatial variabilities in porosity. This simplification is made due to the prohibitive computational costs associated with explicitly modeling spatially varying microstructures in a macroscopic component. To address this challenge, we propose a data-driven framework that integrates a mechanistic reduced-order model (ROM) with a calibration scheme based on latent map Gaussian processes (LMGPs). Our ROM drastically accelerates direct numerical simulations (DNS) by using a stabilized damage algorithm and systematically reducing the degrees of freedom via clustering. Since clustering affects local strain fields and hence the fracture response, we construct a multi-fidelity LMGP to inversely estimate the damage parameters of an ROM as a function of microstructure and clustering level such that the ROM faithfully surrogates DNS. We demonstrate the application of our framework in predicting the damage behavior of a multiscale metallic component with spatially varying porosity.
Generative Pre-Trained Transformers for Biologically Inspired Design
Authors: Zhu Qihao , Zhang Xinyu , Luo Jianxi
Published: November 2022

Biological systems in nature have evolved for millions of years to adapt and survive the environment. Many features they developed can be inspirational and beneficial for solving technical problems in modern industries. This leads to a specific form of design-by-analogy called bio-inspired design (BID). Although BID as a design method has been proven beneficial, the gap between biology and engineering continuously hinders designers from effectively applying the method. Therefore, we explore the recent advance of artificial intelligence (AI) for a computational approach to bridge the gap. This paper proposes a generative design approach based on the pre-trained language model (PLM) to automatically retrieve and map biological analogy and generate BID in the form of natural language. The latest generative pre-trained transformer, namely GPT-3, is used as the base PLM. Three types of design concept generators are identified and fine-tuned from the PLM according to the looseness of the problem space representation. Machine evaluators are also fine-tuned to assess the correlation between the domains within the generated BID concepts. The approach is then tested via a case study in which the fine-tuned models are applied to generate and evaluate light-weighted flying car concepts inspired by nature. The results show our approach can generate BID concepts with good performance.
Estimating the Complete Solution Set of the Approximate Path Synthesis Problem for Four-Bar Linkages Using Random Monodromy Loops
Authors: Baskar Aravind , Hills Caroline , Plecnik Mark , Hauenstein Jonathan D.
Published: November 2022

It is natural to employ an optimization algorithm for the approximate kinematic synthesis of linkages. The hope is to find some superior points in the design space that indicate dimensions that are practically useful. One way to achieve this is to find all minima of an objective, then to filter them so the best remain. However, the prospect of finding all minima is bleak unless the optimization problem at hand is particularly small. In this work, we show how to find nearly all minima for a large optimization problem using polynomial homotopy continuation in the approximate synthesis of a four-bar path generator. The system at hand has a Bézout bound of 543,848,665 and a Schnabel estimate to the maximum number of stationary points of 6 · (303,249 ± 713), within a 95% confidence interval. At least with regards to mechanism synthesis, this work represents the largest scale deployment to date of homotopy continuation to solve an unconstrained optimization problem. The challenges of scaling and suggestions for design are given. Example usage for the design of a leg mechanism is given. On the mechanism design front, this is the first presentation of a nearly complete (within the limitations of numerical discernment) solution of the general four-bar optimal path synthesis problem.
Multi-Mode Deformation of Origami Spring: Theoretical Modeling and Experimental Verification
Authors: Zhang Zian , Liu Zuolin , Li Suyi , Fang Hongbin
Published: November 2022

In recent years, earthworm-like robots have been widely concerned by researchers because of their outstanding mobility in various environments. However, most of them only possess up to 2D locomotion owing to the limitation in their structures and materials. Origami springs, with extraordinary multi-mode deformation ability, have promising potential for 3D locomotion. In this study, an analytic model of the origami spring is established by introducing virtual creases to the facets. Four topologically different configurations of a single cell are therefore obtained by changing the mountain and valley assembly of the virtual creases. By iteratively stacking the cells, a rigid-folding model is derived. Besides the conventional axial stretch-twist-coupling, the proposed modeling can also describe the off-axial deformation, including the point-to-point bending, and line-to-line bending. In addition, the potential energy of the multi-mode deformations is investigated by specifying the torsional spring on the creases of the rigid-folding kinematic model. Mechanical properties, including the nonlinear restoring force under axial deformation, and the approximate linear bending moment under off-axial deformation is observed. What’s more, a mode switching phenomenon is for the first time revealed once the structure is folded to the kinematic bifurcation point, and is experimentally evaluated via PETE film-based prototypes. We believe these findings could inspire the avenue for the next generation of the earthworm-like robot with multi-modal motions.
Exploring the Integration of DSM and LCA Tools to Improve Design for Sustainability
Authors: Carter Michael , Basereh Taramsari Hossein , Hoffenson Steven
Published: November 2022

One of the many challenges that engineering designers face today is a deficiency in practical and value-adding design methodologies that consider sustainability. Typically, design for sustainability (DfS) principles that address environmental and social impacts are not prioritized at the same level as economic, physical, and functional needs. Additionally, many newly-introduced DfS methodologies are fragmented and underdeveloped. Furthermore, many methods are catered towards specific niche product domains or corporate workflows, making the application of these methods across a wide range of problems and products a challenge. By investigating the tools and methods available for DfS and identifying their application and limitations, this study explores the integration of design structure matrices (DSMs) and Life Cycle Assessment (LCA) tools to improve DfS. The expectation is that an integrated DSM and LCA will allow designers to explore how a single design change may propagate through to specific changes in environmental and social impacts. The initial development of a full DSM and LCA is demonstrated through two case studies of a reusable water bottle and a micro-pump, showing which components, materials, and processes have the most significant environmental impacts. The results illustrate the value in applying this approach, which may be suitable across a wide range of existing products in an effort to improve DfS.
Design and Implementation of a Power-Dense, Modular, and Compact Serpentine Articulated Tail
Authors: Pressgrove Isaac , Liu Yujiong , Ben-Tzvi Pinhas
Published: November 2022

Inspired by the many examples in nature, serpentine robotic tails can provide a means of expanding the feasible motion and general dexterity of mobile robots. Previous research has proven the effectiveness of robotic tails for the purpose of inertial reorientation through simulation of both simple pendulum and complex serpentine tails. There have been various experiments involving the integration of pendulum tails with a mobile base conducted to date. However, until now integration of more complex tail models has proven difficult. This paper presents an updated design of the existing Roll-Roll-Revolute Tail (R3RT) which can be readily integrated with a mobile base. The new design improves on the power density as well as form factor of the original design. Therefore, a design that is both more effective and easier to integrate with a mobile robotic base is synthesized. Kinematic and dynamic analysis are conducted to generate design targets. These targets are then met through the development of a power-dense actuator and evolution of a modular tail layout. CAD models of the new tail design integrated with the reduced complexity quadruped base are also reviewed. Finally, results of initial testing to prove the performance of the actuators are presented.
Design and Printability Evaluation of Heat Exchangers for Laser Powder Bed Fusion Process
Authors: Liang Xuan , White Lisha , Cagan Jonathan , Rollett Anthony D. , Zhang Yongjie Jessica
Published: November 2022

The structural design and additive manufacturing (AM) of cross-flow heat exchangers (HXs) are studied. A unit-based design framework is proposed to optimize the channel configuration in order to improve heat exchange performance (HXP) and meanwhile control pressure drop (PD) between the fluid inlet and outlet. A gradient-based optimization methodology is employed to drive the iterative design process. Both shape and topology changes are observed during the channel configuration evolution. Moreover, AM printability evaluation is considered and some re-design work is proposed with respect to metal laser powder bed fusion (LPBF) process. For an original optimized structure from the unit-based design, corner rounding operation is adopted first, specifically to avoid sharp features. Then the building process of the entire cross-flow HX containing the top, bottom caps, surrounding walls and the optimized thin-walled channels is simulated, and residual deformation is predicted through the sequential layer-by-layer analysis. Based on residual deformation profile, geometrical compensation is implemented for the 3D reconstructed model to reduce geometrical inaccuracy of the printed HX. Finally, a mature design scheme for cross-flow HX can be achieved as the solution that leads to largely improved HXP (e.g., nearly 200% increase), well controlled PD and enhanced printability with respect to the LPBF AM process.
Computational Design of Additively Manufactured Curvilinear Scaffolds for Bone Repair
Authors: Cohen David O. , Aboutaleb Sohaila M. G. , Wagoner Johnson Amy , Norato Julian A.
Published: November 2022

This work introduces a computational method for designing ceramic scaffolds fabricated via direct ink writing (DIW) for maximum bone growth, whereby the deposited rods are curvilinear. A mechanobiological model of bone adaptation is used to compute bone growth into the scaffold, taking into account the shape of the defect, the applied loading, and the density distribution of bone in which the scaffold is implanted. The method ensures smooth, continuously varying rod contours are produced which are ideal for the DIW process. The method uses level sets of radial basis functions to fully define the scaffold geometry with a small number of design variables, minimizing the optimization’s computational cost. Effective elastic and diffusive properties of the scaffold as a function of the scaffold design and the bone density are obtained from previously constructed surrogates. These property surrogates are in turn used to perform bone adaptation simulations of the scaffold-bone system. Design sensitivities of the bone ingrowth within the scaffold are efficiently obtained using a finite difference scheme implemented in parallel. A demonstration of the methodology on a scaffold implanted in a pig mandible is presented. The scaffold is optimized to maximize bone ingrowth with geometric constraints to conform to the manufacturing process.
A Modular Continuum Manipulator for Aerial Manipulation and Perching
Authors: Zhao Qianwen , Zhang Guoqing , Jafarnejadsani Hamidreza , Wang Long
Published: November 2022

Most aerial manipulators use serial rigid-link designs, which results in large forces when initiating contacts during manipulation and could cause flight stability difficulty. This limitation could potentially be improved by the compliance of continuum manipulators.

To achieve this goal, we present the novel design of a compact, lightweight, and modular cable-driven continuum manipulator for aerial drones. We then derive a complete modeling framework for its kinematics, statics, and stiffness (compliance). The framework is essential for integrating the manipulator to aerial drones. Finally, we report preliminary experimental validations of the hardware prototype, providing insights on its manipulation feasibility. Future work includes the integration and test of the proposed continuum manipulator with aerial drones.
Parametric Analysis of Negative Capacitance Circuit for Enhanced Vibration Suppression Through Piezoelectric Shunt
Authors: Wang Ting , Tang Jiong
Published: November 2022

Piezoelectric transducers are widely employed in vibration control and energy harvesting. The effective electro-mechanical coupling of a piezoelectric system is related to the inherent capacitance of the piezoelectric transducer. It is known that passive vibration suppression through piezoelectric LC shunt can be enhanced with the integration of negative capacitance which however requires a power supply. This research focuses on the parametric investigation of a self-sustainable negative capacitance where the piezoelectric transducer is concurrently used in both vibration suppression and energy harvesting through LC shunt. The basic idea is to utilize the energy harvesting functionality of the piezoelectric transducer to aid the usage of negative capacitance in terms of power supply. Specifically, the power consumption and circuitry performance with respect to negative capacitance circuit design is analyzed thoroughly. Indeed, the net power generation is the difference between available power in the shunt circuit and the power consumption of the negative capacitance circuit. There exists complex tradeoffs between net power generation and the vibration suppression performance when we use different resistance values in the negative capacitance circuit. It is demonstrated through correlated analytical simulation and experimental study that the proper selection of the resistance values in the negative capacitance circuit can result in vibration suppression enhancement as well as improved net power generation, leading to a self-sustainable negative capacitance scheme.
The Effect of the Balance Board Mass on the Stability, Equilibrium, and Robustness of the Human-Balance Board System
Authors: Chumacero Erik , Yang James
Published: November 2022

People with neuromuscular deficits may show balance issues that put them in a higher risk of fall as compared to healthy people. To reduce the risk of fall, balance-board (BB)-based rehabilitation intervention has been widely used. However, despite the extensive use of BB-based interventions, the mechanisms responsible for rehabilitation remain unclear. To better understand these mechanisms, several studies have used a system dynamics approach to investigate the effect of neuromuscular deficits (visual, vestibular, proprioceptive) and sensorimotor latencies on the stability and dynamical behavior of the human-BB system. Though, to the best knowledge of the authors, the effect of the BB mass on the stability and dynamics of the human-BB system has never been investigated. In the present study, bifurcation analyses, root finding techniques, and computational simulations are used to investigate the effect of the BB mass and BB time-delay on the stability, equilibrium, and robustness of the human-BB upright posture (UP) for cases where either proprioceptive or visual and vestibular deficits are considered. The results show that the BB mass and BB time-delay play a critical role on the UP stability, leaning postures, and robustness of the human-BB system. In fact, increasing BB mass reduces the range of neuromuscular gains that stabilize the system and shrinks the basin of attraction of the UP, which is related to the human-BB system’s robustness to posture disturbances. This effect is more evident in the case where visual and vestibular deficits are considered in simulation. This relationship may have implications on the design and development of BBs with tunable mass and tunable time-delay. The BB could be designed to tune time-delay and mass, so patients could be better challenged during BB-based intervention in a more patient-specific manner.
Design of Constant-Force Wristbands for a Wearable Health Device
Authors: Naylor Thomas , Black Roger , Hernandez Cameron , McMullin Paul , Jensen Brian D.
Published: November 2022

This paper presents the design and testing of a wrist-worn Wearable Health Device (WHD) with an integrated compliant Constant-Force Mechanism (CFM) as part of the wrist band, acting to keep the band tension constant. An integrated CFM can keep pressure on the wrist constant or near-constant, thereby solving one of the main difficulties (movement of and varying force on the sensor area) that wrist-worn WHDs face. The design requirements for a constant-force wristband were narrowed down to seven critical requirements. Multiple CFMs were explored with two main concepts (buckling beams and tape springs) prototyped and evaluated against the key requirements. The tape spring concept was chosen for human subject trials testing due to the mechanism’s better performance compared to the buckling beams concept. The human subject testing (IRB2020-268) compares pressure on the wrist for both a band with and without an integrated CFM for eight different movement activities. The band with the integrated CFM produced reduced variation in the pressure on the wrist, but the difference was not significant. In addition, it was found that, even with the CFM, the band’s sensor location shifted during human motion. Future work will focus on alternative ways of reducing pressure variation, including constant force mechanisms that apply force directly to the sensor package, rather than acting to keep band tension constant.