bluuebunny/crossref_metadata_2025_split huggingface dataset:
Deep Ensembles for Modeling Uncertain Phase Constraints In Compositionally Graded Alloy Design
Authors: Allen Marshall , Arroyave Raymundo , Malak Richard 
Published: November 2022

Abstract
Compositionally graded alloys (CGAs) are a specific class of multi-material functionally graded materials (FGMs) that use spatial variations in alloy composition to meet competing performance requirements in at different locations regions of a single part. Directed energy deposition (DED) metal additive technology has enabled the manufacturing of CGAs, but design these alloys remains a challenge. One important challenge is to avoid alloy compositions that result in the formation of deleterious phases during manufacturing. While designers can use CALculation of PHAse Diagram (CALPHAD) models predict the presence of deleterious phases, these calculations tend to be too costly to incorporate directly in a computational design framework. In this work, we apply deep ensembles, or ensembles of deep artificial neural networks (ANNs), to learn a surrogate model of deleterious phase boundaries based on CALPHAD simulations. The learned model is used as a constraint by a path planning algorithm to identify gradient pathway through metal composition space that can be successfully manufactured. We demonstrate the deep ensemble approach in the Fe-Ni-Cr-Ti quaternary system and benchmark it against individual ANNs and a K-nearest neighbors (KNN) approach reported previously. Additionally, we investigate the use of the predicted class probability threshold as a means for understanding surrogate model uncertainty and reasoning about the design space. Lastly, we illustrate how varying the thresholds on constraint probability results in a trade off between manufacturing risk and identifying solutions through narrow passageways.
Does Design Proficiency Matter in Engineering Design Teams? A Computational Model and Experiments
Authors: Brownell Ethan , Cagan Jonathan , Kotovsky Kenneth 
Published: November 2022

Abstract
A cognitively inspired, agent-based model of engineering design proficiency is introduced in this work. Proficiency is modeled using move selection heuristics and problem space search strategies, both of which were extracted from a prior human subjects study. Agent behavior in the Proficient Simulated Annealing Design Agents (PSADA) Model is validated against human designer behavior and performance. A multi-agent model of design teams is then produced with Monte Carlo simulation methods and it confirmed the previous finding that the most proficient member of a configuration design team has the largest impact (positive or negative) on team performance. Further experiments are conducted with different team characteristics. It is found that the effect of individual team member proficiency is reduced in larger teams, but the highest proficiency team member likely remains the most influential. Nominal teams, where team members do not interact and where the best design is taken as the team output, were found to outperform interacting teams. This was due to high proficiency agents making poor decisions during interactions by switching away from their designs to the designs of their lower proficiency teammates. Conclusions about the role that individual team member proficiency plays in engineering design teams is discussed.
Operational Considerations for Active Electromagnetic Suspension Systems
Authors: Galluzzi Renato , Ramirez-Mendoza Ricardo A. , Circosta Salvatore , Bonfitto Angelo , Amati Nicola , Tonoli Andrea 
Published: November 2022

Abstract
The use of active suspensions has been rekindled by increasingly stringent comfort requirements in light of the diffusion of electric and safe-driving vehicles. In particular, electromagnetic solutions can guarantee intrinsic reversibility and regenerative operation, which would allow for energy harvesting and/or reuse on active quadrants. However, the use of non-ideal actuators has an impact in the regenerative and active capabilities of any active damping solution. To address this shortcoming, this work aims at validating optimal active operation. Hence, a linear quadratic regulator is used to tune a linear optimal control strategy in a quarter-car model. This plant is equipped first with an ideal actuator. Later, this device is enhanced with multiple non-ideal features: inertial and friction contributions of the moving parts, compliance of the parts that exchange forces with the suspension and the resistive load of the motor windings. Details regarding comfort, handling, are compared. Then, the realistic actuator model is compared for comfort- and handling-oriented control tasks. For both strategies, operational aspects like dynamic performance, control calibration, suspension duty cycle, damping force-speed characteristics and power absorption are discussed. It is demonstrated that a significant part of the control effort is used to mitigate non-ideal features of the realistic actuator.
Effect of Varied Additives on the Texture and Shape Stability of 3d Printed Mashed Potato and Pumpkin
Authors: Chirico Scheele Stefania , Egan Paul F. 
Published: November 2022

Abstract
Three-dimensional (3D) food printing has grown exponentially in recent years due to its capabilities for customized food designs, minimal food waste, and personalized nutrition. A current challenge in 3D food printing is the design of extrudable food materials that enable customized shape fabrication and retention due to the complexity of food matrices. Additives such as starches and gums have been employed to improve food mechanical properties and thus printability, however, few studies have investigated further food additives that may affect the manufacturability and lifecycle of printed foods. This study investigates the effect of pea protein, corn starch, citric acid, and butter powder when added in different concentrations on the firmness, total work, and shape stability of mashed potato and pumpkin. Results suggest that pea protein addition increases the firmness and total work, citric acid decreases them, while butter powder and corn starch affect mechanics differently depending on the base material. Overall, the addition of butter powder had the best results for printability and shape retention, with a complete design space analysis suggesting prints should have firmness of at least 150g for high shape stability. Knowledge of food additive effects on texture and shape retention of foods can positively influence the design and manufacturing of personalized foods by reducing reliance on trial-and-error design processes to design new food products.
Dynamics of Interface Relocation in an Electroacoustic Su-Schrieffer-Heeger Topological Lattice
Authors: Kuchibhatla Sai Aditya Raman , Leamy Michael J. 
Published: November 2022

Abstract
We propose a reconfigurable, electroacoustic topological insulator inspired by the Su-Schrieffer-Heeger (SSH) lattice and then study dynamically-switched topological interfaces. The electroacoustic unit cell design is composed of a host structure with bonded piezoelectric attachments shunted via negative capacitance circuits. We first identify topological behavior via band structure calculations associated with the unit cell. By selectively modifying the elastic properties of the repeated unit cells via attached shunted circuits, we then join two one-dimensional lattices with mirror symmetry to yield a topologically-protected interface mode. We compute the characteristic frequencies and compare the harmonic response of the structures with and without an interface to show amplitude localization at an interface for a frequency within a topological band gap. Control of the shunted circuits using electrical switches allows for reconfiguration of the structure, thereby permitting relocation of the topological interface at an arbitrary time instant. We present numerical studies simulating the diffusion of energy as the interface is shifted from one location to another, exploiting topological-protection to ensure minimal energy loss in spite of a non-smooth change in the elastic properties of the lattice. Our work demonstrates robust, movable interfaces in one-dimensional elastic media which may find applications in communication devices and acoustic tweezing.
Real-Time Simulation of Ground Vehicles on Deformable Terrain
Authors: Serban Radu , Taves Jay , Zhou Zhenhao 
Published: November 2022

Abstract
Sophisticated modeling and simulation, based on rigid and flexible multibody dynamics, are nowadays a standard procedure in the design and analysis of vehicle systems and are widely adopted for on-road driving. Off-road driving for both terrestrial wheeled and tracked vehicles, as well as wheeled and legged robots and rovers for extra-terrestrial exploration pose additional modeling and simulation challenges, a primary one being that of the vehicle-terrain interaction, modeling of deformable terrain, and terramechanics in general.
Techniques for modeling deformable terrain span an entire range varying in complexity, representation accuracy, and ensuing computational effort. While formulations such as fully-resolved granular dynamics, continuum modeling of granular material, or finite element can provide a high level of accuracy, they do so at a significant cost, even when the implementation leverages parallel computing and/or hardware accelerators. Real-time or faster than real-time terramechanics is a highly desired capability (in applications such as training of autonomous vehicles and robotic systems) or critical capability (in applications such as human-in-the-loop or hardware-in-the-loop).
We present a real-time capable deformable soil implementation, extended from the Soil Contact Model (SCM) developed at the German Aerospace Center which in turn can be viewed as a generalization of the Bekker-Wong and Janosi-Hanamoto semi-empirical models for soil interaction with arbitrary three-dimensional shapes and arbitrary contact patches. This SCM implementation is available, alongside more computationally intensive deformable soil representations, in the open-source multi-physics package Chrono. We describe the overall implementation and the features of the Chrono SCM model, the efficient underlying data structures, the current multi-core parallelization aspects, and its scalability properties for concurrent simulation of multiple vehicles on deformable terrain.
Assessing the Sensitivity on State-Space Variables Through Isometric and Anisometric Integrity Measures
Authors: Belardinelli Pierpaolo , Lenci Stefano 
Published: November 2022

Abstract
A recurrent task in mechanical and structural engineering is to estimate safe working regimes. For dynamical systems, it means to guarantee that the designed motion will be maintained despite perturbing events. Therefore, in order to assess the practical stability, a global analysis must be performed by employing basins of attraction. The phase-space topological study of their size, shape and compactness, it quantifies and relates back to the robustness of the attractive state within a multi stable scenario. This work illustrates how isometric and anisometric integrity measures could be utilized to assess the practical stability of a dynamical system. We document the challenges when tackling a multidimensional problem and a dissimilar sensitivity with respect to different state-space variables.
Artificial Intelligence Based State of Health Estimation With Short-Term Current Profile in Lead-Acid Batteries for Heavy-Duty Vehicles
Authors: Luciani Sara , Feraco Stefano , Bonfitto Angelo , Amati Nicola , Tonoli Andrea , Quaggiotto Maurizio 
Published: November 2022

Abstract
The State of Health (SOH) estimation for automotive batteries is currently assessed with different techniques which may involve long testing procedure or require costly hardware to be implemented. This paper aims at contributing to this domain by exploiting the response of a lead-acid battery with respect to a short-term current profile using an Artificial Neural Network (ANN) classifier for SOH estimation. The method is applicable onboard the vehicle and no additional instrumentation is required on the retained vehicle. The design and validation of a SOH method with a short-term current profile using Artificial Intelligence (AI) in lead-acid batteries, which are commonly used in heavy-duty vehicles for cranking and cabin systems, are presented. The paper validates the considered approach with experimental data, which are representative of actual vehicle operations. In detail, the paper describes the retained hardware and software architectures and the design procedure related to the proposed SOH estimation technique based on AI. The retained lead-acid battery 12 V 225 Ah battery used in actual heavy-duty vehicles. The proposed AI-based algorithm relies on an ANN used for SOH classification, which is trained with a sufficient amount of collected data. Specifically, the proposed SOH classifier can process features extracted from buffers of input data that are recorded onboard. When considering the validation dataset only, the resulting SOH estimation algorithm can classify the battery SOH with an overall accuracy equal to 96.7%.
Jamming-Reinforced Inflatable Beams for Mobile Robotics
Authors: Weston-Dawkes William P. , Tolley Michael T. 
Published: November 2022

Abstract
Inflatable limbs have the potential to enable robots that are lightweight, deployable from a small package, and can navigate confined spaces. However, the load bearing capability of slender inflatable tubes is limited by buckling loads that occur with modest loading. In this work we explore the use of inflatable beams with layer-jamming skins that are compliant while deflated, but provide enhanced stiffness and load bearing capabilities when inflated. We first describe a fabrication method for the inflatable beam and present a model to predict the length scales at which jamming contributes to the overall performance of the inflatable beam. We then measure the performance of prototype jamming limbs using bending and tip-deflection tests to evaluate the ability of the jamming skin to mitigate the buckling failure inherent in inflatable beams. Finally, we incorporate four jamming-reinforced limbs into a mobile robotic system. To demonstrate the benefits of a hybrid rigid-soft mobile robotic system, we experimentally test the trade-off between walking more quickly with pressurized limbs (1 cm/s), versus navigating confined spaces with depressurized limbs (0.6 mm/s). Incorporating jamming reinforcement into inflatable beams provides improved stiffness and graceful failure rather than the catastrophic buckling that normally characterizes inflated cylindrical beams. Inflatable limbs augmented with pressure-based jamming are not drop-in replacements for rigid links. However, our results show that using layer jamming to provide nuanced soft to stiff capabilities may be valuable for specific environmental constraints.
Collision-Free Dynamic Window Approach for Moving Obstacles
Authors: Xi Zhimin 
Published: November 2022

Abstract
Dynamic window approach (DWA) is known as collision-free for static obstacles with proper design. Under static operation conditions, if there is no admissible velocity within the velocity dynamic window, the agent reduces the velocity as much as possible. As such, the agent is collision-free as long as the projected time is large enough to make the agent fully stop. Existing work of the DWA considering moving obstacles demands for trajectory prediction of moving obstacles so that admissible velocities of the agent can be determined. However, there is no guarantee for any trajectory prediction method that the predicted trajectory is accurate even considering prediction confidence. Hence, collisions are reported for the DWA considering moving obstacles. This paper proposes collision-free DWA for moving obstacles through determination of the mobility of moving obstacles within each control cycle. Algorithms are proposed to efficiently determine admissible velocity of the agent considering the mobility of moving obstacles. Collision-free results are demonstrated through two case studies including an open space navigation and a merging lane navigation through the comparisons with the DWA based on the trajectory prediction.
Analytic Velocity Obstacle for Efficient Collision Avoidance
Authors: Xi Zhimin , Torkamani Elnaz Asghari 
Published: November 2022

Abstract
Velocity obstacle is one of popular reactive navigation algorithms for path planning of autonomous agents. The collision-free property can be guaranteed if the agent is able to choose a velocity outside the velocity obstacle region under the assumption that obstacles maintain a constant velocity within the control cycle time of the agent. To date, selection of the optimal velocity relies on either sampling or optimization approaches. The sampling approach can maintain the same amount of computation cost but may miss feasible solutions under collision risks with insufficient number of samples. The optimization approach such as the linear programming demands for convexity of the constraints in the velocity space which may not be satisfied considering non-holonomic agents. In addition, the algorithm has varying computation demand depending on the navigation situation. This paper proposes an analytic approach for choosing a candidate velocity rather than relying on the sampling or optimization approaches. The analytic approach can significantly reduce computation cost without sacrificing the performance. Agents with both holonomic and non-holonomic constraints are considered to demonstrate the performance and efficiency of the proposed approach. Extensive comparison studies with static, non-reactive, and reactive moving obstacles demonstrate that the analytical velocity obstacle is computationally much more efficient than the optimization based approach and performs better than the sampling based approach1.
Comparing Nominal and Interacting Sub-Structured Teams in an Interdisciplinary Engineering Design Task
Authors: Gyory Joshua T. , Soria Zurita Nicolás F. , Cagan Jonathan , McComb Christopher 
Published: November 2022

Abstract
Teams are common throughout engineering practice and industry when solving complex, interdisciplinary problems. Previous works in engineering problem solving have studied the effectiveness of teams and individuals, showing that in some circumstances, individuals can outperform collaborative teams working on the same task. The current work extends these insights to novel team configurations in large interdisciplinary teams. In these team configurations, the meta-team as a whole can interact but the sub-teams within them may or may not. Here, team performance and process are studied within the context of a complex drone design and path-planning problem. Via a collaborative research platform called HyForm, communication and behavioral patterns can be tracked and analyzed throughout problem solving. This works shows that nominal sub-structured teams, where members work independently, outperform interacting sub-structured teams. While problem-solving actions remain consistent, communication patterns significantly differ, with nominal sub-structured teams communicating significantly less. Questionnaires reveal that the manager roles in the nominal sub-structured teams, which are more central in communication and information flow, experience a greater cognitive and workload burden than their counterparts in the interacting sub-structured teams. Overall, this work adds to the literature on nominal versus interacting problem-solving teams, extending the finding to larger, interdisciplinary teams.
Design, Analysis, and Prototyping of a Novel Single Degree-of-Freedom Index Finger Exoskeleton Mechanism
Authors: Xu Wenda , Liu Yujiong , Ben-Tzvi Pinhas 
Published: November 2022

Abstract
This paper presents a novel index finger exoskeleton mechanism for patients who suffer from brachial plexus injuries, which takes advantage of our previously proposed rigid coupling hybrid mechanism (RCHM) concept used for robotic tail mechanisms. The core idea of this concept is to drive the (i+1)-th link using the motions of the i-th link, instead of the traditional way of transmitting motion directly from the base. This specific configuration allows designing a single degree of freedom (DOF) bending mechanism using a low-profile rack and pinion mechanism and makes the proposed exoskeleton system compact, lightweight, and portable, which are highly desired features for daily usages of exoskeleton gloves. The mechanism is optimized to mimic the grasping motions of human fingers and the sensitivity analysis of its critical design variables is then conducted to explore the performance of the optimization results. The results show that for the current design, the tip position accuracy is mainly affected by the distance between the rack and the corresponding joints. A proof-of-concept prototype was built to verify the novel mobility of the proposed mechanism and to evaluate its performance on a human finger. The index finger exoskeleton experiments demonstrate the new mechanism’s ability to grasp small objects.
Design of Three-Dimensional Bi-Continuous Silicon Based Electrode Materials for High Energy Density Batteries
Authors: Zheng Zhuoyuan , Liu Zheng , Wang Pingfeng , Li Yumeng 
Published: November 2022

Abstract
Silicon-based anode is a promising candidate for next generation lithium-ion batteries (LIBs) with improved energy and power density. However, the practical application of Si anode is hindered by their major reliability issue that Si experiences significant volume change during its lithiation/delithiation cycles, leading to high stress, degradation, and pulverization of the anode. With the development of advanced electrode fabrication technologies, structured Si anodes with delicately designed architectures have been proposed. This study focuses on five triply periodic minimal surface (TPMS) based 3D bi-continuous porous Si anodes, which consist of the nano structured metal scaffolds and conformally coated Si layers and explores their lithiation-induced stresses via numerical methods. The multi-physics based finite element (FE) models are firstly built to simulate the deformation and stress of Si anodes during lithiation processes. Afterwards, the Gaussian Processes (GP) based surrogate model is developed to assist the design optimization of the Si anodes within the design space. It is found that, the inverse FCC and diamond surface-based Si anodes show better performances with the lowest stress concentration. In addition, with the decrease of Si phase volume fraction and increase of scaffold fraction, the stresses can be further reduced.