bluuebunny/crossref_metadata_2025 huggingface dataset:
Extended Position-Based Dynamics Virtual Reality Simulator for Thoracoscopic Surgery Training
Authors: Piazzolla Pietro , Rossoni Marco , Buttiglione Marco Domenico , Lucania Elena , Colombo Giorgio , Guerrera Francesco , Gribaudo Marco
Published: November 2024

Conducting thoracoscopic surgery necessitates a high level of skill and specialized training. In addition to practicing on actual patients, surgeons utilize various safer training methods. A widely used training apparatus is the laparoscopic box, which contains multiple compartments fitted with training modules to replicate diverse surgical scenarios accurately. Unfortunately, the cost of these devices can be prohibitively high, making it challenging for individual students to acquire their own. Virtual Reality has emerged as a promising solution, especially due to the decreasing costs of VR equipment, which makes it more accessible. This study details our progress in enhancing training for lung surgeries by leveraging cost-effective VR technologies with head-mounted displays. In particular, simulations of thoracoscopic surgery scenarios within a VR environment have been developed, aiming to create training exercises that serve as an initial step before advancing to laparoscopic simulation boxes and, ultimately, actual surgical procedures on patients. For reproducing the behaviour of the soft lung tissues, we used a recent version of the Extended Position-Based Dynamics (XPBD) model, which solves some of the known problems encountered in the traditional PBD system, thereby enhancing the realism of the simulation.
The Third Law of Gearing: A Surface Defining Maximum Relative Curvature of Conjugate Gear Flanks
Authors: Dooner David
Published: November 2024

Gear flanks are a special case of two surfaces in direct contact; the restriction being that the surface normal between the two flanks maintains a desired gear speed ratio. This restriction is commonly referred to as reciprocity and the surfaces are considered conjugate. At any instant, there exists a maximum and minimum relative curvature for conjugated gear flanks. These extreme curvature values are affected by tooth profile modifications (viz., profile relief and lead crown). The third law of gearing establishes limiting values on the extreme relative curvatures for unmodified gear flanks. The lower limit is zero implying line contact between the gear flanks. The upper limit on the relative curvature between gear flank depends on the instantaneous pressure angle, spiral angle, and gear architecture (viz., speed ratio, shaft angle, and offset). An overview of these relations is presented. Introduced is a curvature surface that illustrates all candidate maximum relative curvatures by considering all possible pressure angles. This surface is independent of the tooth profile geometry (viz., involute, cycloid, or other). An automotive hypoid gear set is presented to illustrate the curvature surface.
On the Improved Efficiency of Higher-Order Dynamics for Computing Resonant Frequencies
Authors: Becker Eric T. , Inman Daniel J. , Sanders John W.
Published: November 2024

It was recently discovered that higher-order dynamics are intrinsically variational, in the sense that higher-derivative versions of the classical equations of motion can always be derived from a minimum-action principle similar to Hamilton’s principle, even when the physical system is non-conservative. This discovery has already led to several applications, including a new and more efficient algorithm for computing a non-proportionally damped system’s resonant frequencies, based on the fourth-order system dynamics. The purpose of this paper is to investigate the source of this improved efficiency in greater detail. We find that the improved efficiency of the new resonant frequency algorithm is due almost entirely to savings in computing the eigenvalues of the system’s stiffness matrix Ω˜. This result is surprising in light of the ostensible complexity of this matrix. Nevertheless, the savings are shown to be statistically significant, with attained significance levels below machine precision. Although a rigorous mathematical explanation remains elusive, empirical results presented here lead us to conjecture that the reason may have to do with the unique block structure of the stiffness matrix, which it inherits from the mathematically Hamiltonian structure of the fourth-order formulation. The present authors believe there may be additional applications of higher-order dynamics waiting to be discovered, and we conclude the paper with a few potential ideas to explore.
Extension of Hamiltonian Mechanics to Non-Conservative Systems
Authors: Sanders John W. , Becker Eric T. , DeVoria Adam C.
Published: November 2024

This paper presents a detailed review of the emerging topic of higher-order dynamics and their intrinsic variational structure, which has enabled — for the very first time in history — the general application of Hamiltonian formalism to non-conservative systems. Here the general theory is presented alongside several interesting applications that have been discovered to date. These include the direct modal analysis of non-proportionally damped dynamical systems, a new and more efficient algorithm for computing the resonant frequencies of damped systems with many degrees of freedom, and a canonical Hamiltonian formulation of the Navier-Stokes problem. A significant merit of the Hamiltonian formalism is that it leads to the transformation theory of Hamilton and Jacobi, and specifically the Hamilton-Jacobi equation, which reduces even the most complicated of problems to the search for a single scalar function (or functional, for problems in continuum mechanics). With the extension of the Hamiltonian framework to non-conservative systems, now every problem in classical mechanics can be reduced to the search for a single scalar. This discovery provides abundant opportunities for further research, and here we list just a few potential ideas. Indeed, the present authors believe there may be many more applications of higher-order dynamics waiting to be discovered.
Student Understanding of Prototyping in Capstone Projects
Authors: Adebayo Oredola , Kumar Pavan , Malik Vipul , Summers Joshua D.
Published: November 2024

This study investigates the evolving understanding and application of prototyping among twenty undergraduate mechanical engineering students involved in their capstone projects. Employing a four-stage survey design approach, the research explores how students’ baseline knowledge, perceptions, and collaborative experiences with prototyping evolve throughout the project. Student definitions of prototyping are compared to a literature-based definition to determine conceptual understanding. These, in addition to other student factors, such as types of prototypes, facilities, tools used in the past are aggregated into composite team profiles that are compared. This includes systematically capturing the students’ conceptual understanding through definitions that are compared with established literature-based definitions of prototypes and prototyping. Additionally, the evolution of students’ perceptions of prototyping is elucidated. It is seen that students and teams’ perceptions of prototyping do change throughout the project, likely because of engaging with the prototypes. The results reveal that while a deeper grasp of prototyping does not align with proficient results, it generally leads to avoiding poor project outcomes. This emphasizes the importance of equipping students with early exposure and knowledge of prototyping principles. This study aims to inform educational practices and encourage effective use of prototyping in capstone projects and real-world engineering contexts, ultimately providing valuable insights into its role in student learning and project success.
Development of a Hybrid Harvester for Collecting Energy From Wind and Vibrations in Light Vehicles
Authors: Pasetto Alberto , Tonan Michele , Doria Alberto
Published: November 2024

A bicycle experiences road-excited vibrations and is impacted by a wind flow. Both these phenomena can be exploited for energy harvesting. Previous research showed that the tuning of the harvester to road-excited vibrations requires a low natural frequency that can be achieved by means of a large tip mass. This tip mass can be used to equip the harvester with a bluff body for energy harvesting from wind-excited vibrations. The interaction between the bluff body and the wind flow generates a vortex shedding phenomenon that at a certain wind velocity is able to excite the harvester in resonance condition. Moreover, the turbulence of the incoming wind is able to excite the bluff body in the high velocity range (buffeting excitation). The paper deals with mathematical and experimental analyses for the development of a hybrid piezoelectric harvester able to scavenge energy from road-excited vibrations and wind. A multi-physical mathematical model that takes into account the couplings between the mechanical, electrical and fluid domains is developed. The coupled equations are solved in Matlab and are used for the harvester design. Two prototypes are developed and tested. The results of experimental tests carried out in a wind tunnel and in open space show the potentialities of the proposed harvester layout.
Development and Validation of a 3d Force and Moment Balancing Simulation Software for Evaluating Wall Climbing Robots on Varied Surfaces
Authors: Elgavish Ethan , Pryor Mitch
Published: November 2024

This paper presents the development and validation of a software tool for evaluating the performance of wall climbing robots across a wide spectrum of orientations, surfaces, and surface curvatures. Utilizing a three-dimensional force and moment balancing algorithm, the software predicts potential failure modes pertinent to various designs and adherence modalities of wall climbing robots. The algorithm’s architecture enables it to accommodate different surface types, robot configurations, and adherence mechanisms, making it a versatile tool for robotic research and development. The accuracy of the simulation is validated through experimental testing with a suction-based wall climbing robot developed to inspect horizontal dry cask storage cylinders for spent nuclear fuel. Additionally, the paper illustrates the software’s extensibility by adapting the algorithm for a magnetic wall climbing robot utilized on vertical tanks in the Oil and Gas industry, showcasing its broad applicability in enhancing the design and performance of robotic systems. The findings not only highlight the critical role of geometric and mechanical parameters in robot performance but also offer insights into optimizing robot designs for improved functionality and reliability. This tool has been made available to the robotics and design community, facilitating the advancement of wall climbing robots for industrial and research applications.
Seamless Integration of Multibody and Orbital Dynamics to Support Human Spaceflight Simulations
Authors: Sullivan Christopher C. , Brain Thomas A. , Quiocho Leslie J.
Published: November 2024

At the NASA Johnson Space Center (JSC), modeling capability requirements are often driven by the need to simulate upcoming mission scenarios for analysis, procedures development, and training. In preparation for free-flyer vehicle capture, maneuvers, and release, it was determined that the multibody dynamics capabilities provided by MBDyn and the orbital dynamics capabilities supplied by JEOD needed to be merged to properly simulate the dynamic behaviors expected on orbit. After initial attempts to combine the two packages proved cumbersome, it was decided that a more refined solution was required to facilitate the interface between these two packages. The resulting interface software package was named MBJEOD. The primary design goals for this new package were to leave MBDyn and JEOD untouched, to simplify and clarify simulation initialization for users, and to support any topology or on-orbit operational scenario that future missions might require. This paper provides a detailed overview of MBJEOD and the approach taken to seamlessly integrate the multibody dynamics of MBDyn with the orbital dynamics of JEOD. Additional attention is given to the numerical considerations required for MBJEOD and the simplifying assumptions leveraged to provide for real-time simulation needs. Verification and validation are addressed and current MBJEOD applications at the NASA JSC are discussed.
Modal Analysis Technique of Metal Pushing V-Belt During CVT Operation
Authors: Saito Toshihiro
Published: November 2024

A finite element analysis method has been developed to clarify metal belt vibration modes during CVT ratio shift transition. A feedback control program that follows the target ratio was compiled and linked to an explicit finite element solver for the metal belt behavior during actual CVT operation, and the friction characteristics of the belt sliding parts were also reflected in the analysis model. Based on the obtained finite element strain and displacement states at arbitrary times, contact constraints were automatically applied and an implicit finite element modal analysis was conducted. Vibration modes that match with metal V-belt noise frequencies and the effect of sliding velocity on dynamic friction characteristics were quantitatively clarified.
Plant Fairy: Improve Human-Plant Interaction for Children
Authors: Lu Yujia , Zhou Yi , Gong Hebo , Li Yan
Published: November 2024

This study aimed to facilitate interaction between children and plants as a form of education about ecosystem conservation. Planting is a desired access to contact with nature in the family environment because it is safer than animals and easy care. But children may have trouble treating plants as nature life, and may not find them attractive. Plants essentially have no ability to voluntarily move, express themselves and vocalize; thus, they are hard to give instant feedback to get human’s attention and evoke human’s empathy. In light of these conditions, we propose an interactive system, called Plant Fairy, that uses augmented reality as an expressive medium to anthropomorphize plants and create a more dynamic and engaging experience to evoke children’s empathy and convey plants’ needs for survival to children. The system comprises environmental sensors and an AR interface that communicates via Bluetooth to translates environmental changes and human interactions into visual and auditory feedback. We conduct a user study with children and their caregivers to confirm the system’s effectiveness. The results indicate our system can improve children’s perception of plants as living entities and be more attractive to children than normal plants. Overall, the “Plant Fairy” system demonstrates the potential of AR in education, particularly for stimulating children’s cognitive development and fostering a deeper understanding of plant life.
Comparative Analysis of the Mechanical Behavior of Conjugated Face-Milled and Face-Hobbed Hypoid Gear Drives
Authors: Gonzalez-Perez Ignacio , Fuentes-Aznar Alfonso
Published: November 2024

A comparative analysis of the mechanical behavior of conjugated face-milled and face-hobbed hypoid gear drives is presented. The analytical determination of the basic machine-tool settings is conducted for both systems of generation and applicable to hypoid gear drives at any shaft angle, assuring the absence of kinematic transmission errors. However, the implementation of a tip relief is required to ensure a smooth load transition between consecutive pairs of teeth while preserving the conjugated action between tooth surfaces. The impact of the generating process and cutter radius selection on contact stress, bending stress, loaded transmission errors, efficiency, and sensitivity of the contact pattern to the presence of errors of alignment is presented. The comparative analysis reveals a similar mechanical behavior for both systems of generation, although in face-hobbed hypoid gear drives it is possible to slightly reduce the level of contact stress compared to face-milled hypoid gear drives for the same cutter radius selection. Furthermore, although increasing the cutter radius provides a modest reduction in contact stresses, a detailed sensitivity analysis of contact pattern shifts due to alignment errors highlights the importance of selecting the cutter radius within the lower bounds of the range recommended by the Information Sheet AGMA 22849-A12.
A Statistical Shape Model of Femur of ACL-Injured Knee
Authors: Ghidotti Anna , Regazzoni Daniele , Weiss Cohen Miri , Condello Vincenzo
Published: November 2024

Injuries to the anterior cruciate ligament (ACL) are common among active populations. The shape and anatomical variations of the bones are directly related to the function of the ACL, and therefore are considered to be risk factors for injury. This research aims to delineate the key patterns of shape variation in femurs affected by ACL injuries through the application of Statistical Shape Modelling (SSM). SSM is applied to 50 distal femur models and their modes of variations are described. Ten morphologically significant parameters of the distal femur bone are selected and measured on a 3D model of the mean femur, as well as the −3SD and +3SD shapes of the first three principal components (PCs). The first principal component reflects the variation in size of the femur. The second principal component is mainly related to the width of the notch. A variation in the height of the medial posterior condyle is observed in the third principal component. Nevertheless, it is not as significant as with the first two PCs. The study presents a statistical shape model for characterizing the fundamental modes of geometric variation in femoral bones following an ACL injury. Knowing the bony morphological features associated with ACL injuries is crucial to tailoring treatment plans to each individual.
Automatic Kinematic Alignment of Flexures in Parallel Mechanisms
Authors: Piening Patrick V. L. , Nijenhuis Marijn , Aarts Ronald G. K. M. , Brouwer Dannis M.
Published: November 2024

Compliant mechanisms offer a number of benefits over sliding joint based mechanisms; however, their design is more complicated. As a result multiple design methods have been developed to assist with the design of compliant mechanisms. The kinematic FACT method assists in the manual design of mechanisms but has seen limited use in computational optimization. This research presents an alternative kinematics based computational optimization approach towards the automatic placement of a chosen set of flexures in 3D space such that a desired constraint space is obtained while minimizing the redundancy of constraints within a parallel spatial mechanism. A continuous measure for vector space misalignment is developed and utilized in a cost function optimization to manipulate the coordinate frame transformation of screws associated with flexural building blocks. This continuous measure is also used to formulate constraints for the cost function optimization. The approach is tested in three design cases within a limited design volume: a spherical hinge composed of wire flexures, a single rotation degree of freedom (DOF) hinge composed of leaf flexures and a parallel mechanism with three non-intersecting rotational DOFs consisting of wire flexures. The flexures are introduced and optimized sequentially and kinematically valid designs are obtained. This research is a stepping stone towards the development of a more general automatic 3D building block based synthesis approach for compliant mechanisms.
Development of a Comprehensive Linear Finite Element Model of the Human Wrist Joint
Authors: Mena Andres , Wollstein Ronit , Yang James
Published: November 2024

This study presents a linear finite element model for the human wrist, constructed from a CT scan of a 68-year-old male (type I wrist). This model intricately captures the bones, soft tissues, and ligaments to study the biomechanics of static grasping by applying pressure loads on the five metacarpals. The results show radial transmission of the load, consistent with findings from wrist finite element models conducted in the last decade and other experimental in vitro studies. Validation is explored through the assessment of carpal resultant displacement. Our preliminary results confirm the model’s efficacy in reproducing key biomechanical aspects, laying the groundwork for future investigations into ongoing wrist biomechanics challenges.
Automated Sub-Feature Labeling Using Prompt-Based Pretrained Language Model
Authors: Park Seyoung , Jiang Yilan , Kim Harrison
Published: November 2024

Many studies have been utilizing online user-generated data to draw product design implications via supervised and unsupervised approaches. While the supervised learning methods typically yield higher performance, they demand extensive data labeling tasks, consuming significant time and effort. This study proposes a framework that automatically labels online user data to address this limitation. The proposed framework consists of two pseudo-labeling mechanisms, keyword detection and prompting Pretraied Language Model (PLM). The first stage defines keywords for the target topic and then labels datasets by checking if the data contains these keywords. The second stage employs the PLM and labels datasets based on their context. Specifically, Prompting PLM adds a task-specific template at the end of the given text data (review) and predicts the masked token (label). This PLM-based approach serves as promising labeling candidates as they can make predictions without additional training data from the target domain. The suggested method was tested on a case study with real-world datasets. The study validates the effectiveness of this novel framework by comparing the pseudo-labeled results on smartphone sub-features to manual ground-truths. The results demonstrate that the new framework achieves F1 scores 28% and 14% higher than a baseline for screen and battery, respectively.
Techno-Economic Outlooks for the Operation of Zero-Emission Heavy-Duty Trucks: Their Implications on Fleet Operators, Cargo Shippers, and Vehicle Designers
Authors: Liang ZhiYi , Dupont Bryony L. , Winter Amos G.
Published: November 2024

Heavy-duty trucking is an essential economic sector and the logistical backbone of the American and global economy. However, heavy-duty vehicles (HDVs) contribute significant CO2 emissions to global warming. HDVs are hard to decarbonize due to the large amount of onboard energy storage required for the range and towing performance needed. Currently, there are two potential promising alternative drivetrain architectures to replace existing diesel fleets: lithium battery-electric vehicle (Li-BEV) and hydrogen fuel-cell-electric vehicle (H2 FCEV). While these alternative-fuel HDVs are on their way toward technical maturity and commercialization, the techno-economic implications of operating a zero-emission fleet remain largely uncertain to stakeholders in the trucking industry. In this study, we developed a multi-dimensional techno-economic model to evaluate the technical constraints of onboard energy storage in HDVs and compare the operational technoeconomics of zero-emission drivetrains against diesel vehicles, using the perspectives of fleet operators and cargo shippers. We have found that although Li-BEV drivetrains show promise in decarbonizing heavy-duty vehicles, they are limited to the short to medium range (< 500 mi) and in applications where freight capacity is not a high priority. In the long-haul freight-carrying scenario above 750 miles, H2 FCEVs are shown to be a better candidate for replacing diesel heavy trucks than Li-BEVs, due to a higher cargo capacity. However, to make H2 FCEVs more competitive in the HDV sector, more proactive investments and infrastructure developments are necessary to establish a mature hydrogen supply chain and to further reduce the price of hydrogen fuel to 2 USD/kgH2. It is also apparent that the operational techno-economics and freight performance of the zero-emission options remain out-competed by existing diesel fleets. Governments would need to put forth aggressive fiscal and regulatory policies to promote the competitiveness of zero-emission drivetrains and limit the use of diesel vehicles.
Design and Fabrication of a Deployable Tensegrity Millirobot for Next-Generation Gastrointestinal Diagnostics and Treatment
Authors: Kazoleas Christian , Zhang Jiajun , Tan Na , Yuan Sichen
Published: November 2024

The advent of robotics in medicine has brought about a paradigm shift, enabling minimally invasive interventions for in-vivo practices. Pill-based robots, specifically designed at the millimeter scale, have emerged as a viable alternative to traditional endoscopic methods for gastrointestinal tract diagnostics and treatment. These millirobots, capable of navigating the complex and constrained environments of the human body, offer a significant advantage by enabling thorough visualization or targeted drug delivery in a single session without the need for sedation. We previously developed a novel deployable tensegrity robot, designed for gastrointestinal diagnostics and treatment, which addresses the limitations of conventional capsule endoscopes through its unique structure and locomotion mechanism. Tensegrity structures, characterized by a network of components in tension and compression, provide an innovative solution to the challenges of designing robots for in-vivo applications. Our millimeter-scale tensegrity robot leverages the inherent advantages of such structures — lightweight, high stiffness, and adaptability — to navigate through densely packed tissues and high-pressure environments within the GI tract. Inspired by the locomotion of earthworms, the movement mechanism of the robot enables efficient navigation and precise positioning, significantly reducing the risk of retention and ensuring patient safety. This paper investigates the design and fabrication process of the tensegrity robot, focusing on achieving a high folding ratio to facilitate its deployment as a pill-based robot. Through a comparison of the robot’s fabricated dimensions with the theoretical design, we evaluate the accuracy of the fabrication process, highlighting the potential of this innovative approach in transforming GI tract diagnostics and treatment. The deployment of such tensegrity-based millirobots marks a new era in medical devices, promising enhanced patient safety and comfort through non-invasive methods.
Swarm Inspired Path-Constrained Motion Planning for Maintaining Communication Within Multiple Robot Systems
Authors: Leong Jabez Kit , Lawrence Brandon J. , Soh Gim Song
Published: November 2024

The involvement of Multi-robot Systems (MRS) in a vast range of missions such as search and rescue, patrolling, exploration and mapping of environments has increased over the years. The working dynamics between MRS and human operators has also evolved to include more human-in-the-loop approaches where the MRS becomes an extension of the human operator(s) to accomplish complex tasks as human-robot teams. This advancement requires a higher frequency of information sharing among the MRS and with the human operator(s) to provide situational awareness so that more informed decisions can be made rapidly. Thus, maintaining communication between the various actors of the team is key to ensure mission success. This paper explores the dynamic challenge of swarm reconfiguration to maintain communication among a system of dynamic nodes — i.e. multiple robots or humans — navigating in an urban environment. Proposed is a hierarchical robotic system that utilises a swarm of Small Supporting Unmanned Ground Vehicles (SSUGVs) as mobile communication breadcrumbs. These SSUGVs dynamically reconfigure themselves through swarm-inspired, path-constrained motion planning to maintain communication within the main system during exploration. The presented solution is verified successfully with hybrid simulations — i.e. a combination of real experimental data with simulated components on a mapping exploration task. The system is studied based on three metrics namely the system connectivity that measures the network connectivity of the overall system, the system response that measures the response of the system to a changing environment, and the average distance travelled of the system that indicates the activity level of the system.
A Piecewise Linear Piezoelectric Energy Harvester With Controllable Gap Size
Authors: Guan Yuqin , D’Souza Kiran
Published: November 2024

Research in the field of vibration energy harvesting has been increasing over the past decade. Researchers have developed various methods to collect unused or wasted energy from physical systems, such as bridges. This paper presents and tests a piecewise-linear (PWL) piezoelectric energy harvester design. Similar studies have been conducted for an electromagnetic energy harvester and have shown the benefit of implementing a PWL energy harvester for some potential applications. This work investigates the performance of the PWL energy harvester using a piezoelectric cantilever beam as the energy generator, which is more suitable for smaller-scale harvesting applications. The design of the piezoelectric cantilever beam system uses a simple control algorithm to maintain the optimal gap size in the system. This design actively adjusts the resonance frequency to maximize power generation over a larger frequency range to make self-powered sensors more viable. The resonance frequency is optimized by adjusting the gap size between the piezoelectric cantilever beam and an elastic stopper using a combination of linear actuators, circuits and microprocessors. The design shows an increased performance in maintaining an optimized vibrating amplitude in the pre-computed frequency range. An experimental realization of the design is tested and compared with the computational prediction to validate the design’s effectiveness.
Parametric Analysis and Design of a Triple-Magnet System for Magnetic Gravity Compensation in Linear Motion
Authors: Li Shuojie , Zeng Xiangxian , Kuo Chin-Hsing
Published: November 2024

This paper introduces, analyzes, and designs a magnetic gravity compensation mechanism utilizing three aligned, parallel cylindrical magnets for balancing linear motion against gravity. Unlike traditional magnet-based designs that employ numerous permanent magnets, this triple-magnet approach offers structural simplicity and high adjustability, suggesting a practical solution concept for linear-type gravity compensation. First, to determine the theoretical magnetic forces, an approach based on Monte Carlo integration is described. Several dimensional factors affecting the interactive forces between the three magnets, such as the magnetic polarization as well as the magnet radius and thickness are thoroughly investigated. It was found that increasing the thicknesses of the magnets will enhance the synthesized magnetic force without affecting the stability of gravity compensation. On the other hand, enlarging the diameters of the magnets will improve the stability of gravity compensation, but there is a bound of maximum diameters for the improvement. Accordingly, a procedure for gravity compensation design of the triple-magnet mechanism is developed. The design philosophy is illustrated through two examples, in which the design results were validated by finite-element simulation. As a result, the presented design concept holds great potential for applications, offering a reliable and efficient solution for magnetic gravity compensation in translational motion.
A Matrix-Based Approach to Unified Synthesis of Planar Four-Bar Mechanisms for Motion Generation With Position, Velocity, and Acceleration Constraints
Authors: Deng Xueting , Purwar Anurag
Published: November 2024

This paper introduces a novel matrix-based approach for the simultaneous type and dimensional synthesis of planar four-bar linkage mechanisms, accommodating various practical constraints, including position, velocity, acceleration, and joint placements. Traditional design processes segregate type synthesis, the determination of joint and link configurations, from dimensional synthesis, which involves specifying link sizes and pivot locations. This segregation often leads to complexities in addressing the complete design challenge. The novel methodology proposed in this paper departs from the conventional sequential design approach by concurrently evaluating type and dimensional parameters using a data-driven matrix formulation. The crux of the paper’s methodology involves formulating a singular design equation through a transformation matrix, parameterized by the Cartesian parameters of the mechanism’s dyads. This formulation linearly expresses a broad range of constraints, facilitating the identification of viable solutions through Singular Value Decomposition (SVD) and Null space analysis. This integrated approach not only simplifies the synthesis process but also provides direct insights into the mechanism’s parameters, encompassing both type and dimensions, thereby obviating the need for further interpretative steps common to the use of quaternions and kinematic mapping. In essence, the paper presents two main contributions: the development of a unified design equation capable of encompassing a wide array of constraints within the mechanism synthesis process, and the introduction of an algorithm that effectively identifies all potential planar four-bar linkage mechanisms by accurately satisfying up to five constraints. This approach promises to enhance the design and optimization of mechanical systems by offering a more holistic and efficient pathway to mechanism synthesis.
Design and Control of a Prosthetic Wrist Mechanism
Authors: Epp Jonas G. E. , Ours Madison K. , Chaplinski Payton A. , Pesch Alexander H.
Published: November 2024

Amputees, whether due to congenital conditions, accidents, or health issues, encounter the daily challenge of navigating life with heightened difficulty in performing essential tasks compared to the general population. While technology has made significant strides in addressing this challenge, there remains a noticeable gap in the availability of high functioning prosthetics for individuals with limited financial resources. Specifically, in the realm of upper extremities, such as the hand and forearm, the need for precise fine motor control adds a layer of complexity to the design considerations for restoring meaningful functionality to patients. Prosthetic options, such as body-powered and electromyography devices, present diverse choices for patients. While body-powered prosthetics rely on cable systems activated by body movements, electromyography prosthetics harness electrical muscle activation for precise control. This paper delves into the intricate design process of an advanced prosthetic arm, with a focus in replicating the pronation and supination of the wrist and forearm. In exploring the intricate problems associated with upper extremity amputations, this studies’ attention centers on Trans-radial amputations, among the most prevalent and complicated cases. The classification system outlines three levels: Hand, Partial Hand and Digits; Trans-radial and Wrist Disarticulation; and Trans-humeral, Elbow Disarticulation, and Shoulder Disarticulation. This research and design aims to restore functionality to Trans-radial amputees, recognizing the pivotal role hand and wrist movements play in daily activities.
Extracting Design Knowledge From Optimization Data: Application to Multi-Split Thermal Management System Configuration
Authors: Bayat Saeid , Shahmansouri Nastaran , Peddada Satya R. T. , Tessier Alex , Butscher Adrian , Allison James T.
Published: November 2024

As engineering systems become more complex, the traditional sources of design knowledge face limits in the rate and complexity of design knowledge generation. Additional sources of knowledge are needed to guide future design efforts, especially for unprecedented engineering systems that have no design heritage. One promising avenue lies in the analysis of design optimization data, which has the potential to offer valuable insights into unprecedented system design, and to break free from incremental improvements over heritage designs. This paper presents a step toward extracting knowledge from design optimization data. The resulting design knowledge can be used as a basis for successfully synthesizing engineering system configurations that are more complex than those the knowledge was derived from. These methods are studied here using the combined system topology and optimal control design of multi-split fluid-based thermal management systems. This knowledge generation approach offers several advantages over traditional strategies, including applicability in cases where there is no design heritage and the ability to provide normative guidance as opposed to descriptive (i.e., how should systems be designed vs. how have they been designed). Four significant case studies with varying levels of complexity are presented that demonstrate the effectiveness of using knowledge extracted from design optimization data in enhancing the design of complex thermal management systems. Our results show that the knowledge extracted in this way provides a good basis for more general design of complex thermal management systems. It is shown that the objective function value of the estimated optimal configuration closely approximates the true optimal configuration with less than 1 percent error, achieved using basic features based on the system heat loads without involving the corresponding optimal open loop control (OLOC) features. This eliminates the need to solve the OLOC problem, leading to reduced computation costs.
FE-Analytical Contact Modeling for the 3D Simulation of Bevel Gear Dynamics
Authors: Vivet Mathijs
Published: November 2024

The numerical prediction of spiral bevel gear contact dynamics is often hampered by the complexity of the gear tooth geometry and the three-dimensional (3D) nature of the motion transfer, which forms a major challenge for efficient contact detection and accurate contact force calculation. This works proposes a novel spiral bevel gear contact force element that enables the accurate prediction of 3D bevel gear contact force distributions in flexible multibody system dynamics simulations (MBDS). An efficient contact detection strategy, based on the surface of action, is used, while the accurate contact force calculation is obtained by inclusion of a new semi-analytical bevel gear contact stiffness model. This stiffness model relies on model order reduction (MOR) of finite element method (FEM)-based models to describe the bevel gear tooth and blank deformation, and analytical modeling to predict the tooth contact deformation. The solution can be used to model and analyze lightweight bevel gear dynamics. The method is validated against high-fidelity nonlinear finite element analysis-based contact simulations to evaluate the predicted transmission error, contact pattern, and contact pressure distribution. Finally, a use case is presented to demonstrate how the methodology enables detailed insights in spiral bevel gearbox dynamics, and noise and vibration (NVH) performance.
Quantitative CAD Archetype Framework Evaluation With Professional User Data
Authors: Zhang Kaiwen , Cheng Kathy , Olechowski Alison
Published: November 2024

In a previous work completed by Zhang et al., a framework for analysing computer-aided design (CAD) user “archetypes” was created, based on the types of user data that can be collected from modern multi-user CAD (MUCAD) user analytics. In this paper, the previously developed CAD archetype framework will be applied to a professional engineering dataset. Various ratios are calculated and presented which show the distribution of users in various dimensions of interest, with evidence of the framework creating separation between users in areas of the CAD workflow. The paper concludes with discussions on future development work to improve the framework robustness.

Understanding the way that users interact with each other in a MUCAD setting will be critical for increasing productivity and enabling companies and professionals to optimise their workflows; research has shown that there are a number of approaches to designing in CAD, and one might imagine that these differences could be understood and classified such that compatibility can be improved, especially in a collaborative context.
Data Driven Metareasoning for Defending a Perimeter Against Cooperative Intrusion
Authors: Namala Prannoy , Vaidya Arjun , Herrmann Jeffrey W.
Published: November 2024

Perimeter defense problem is a type of differential game, where a team of attacker agents try to score by intruding a perimeter region while a team of defenders try to defend the perimeter by intercepting the attackers. There are many approaches to the multi-agent perimeter defense problem proposed over the last decade with varying assumptions. However, even the most general approach cannot generate an optimal solution for every situation. In some situations, a heuristic-based solution might work better than a complex one. Choosing the right solution will help in higher performance and lower computation burden due to the simplicity of the solution. This paper discusses a metareasoning approach for the multi-agent perimeter defense problem. We introduce two data-driven algorithm selection policies, one based on exploratory data analysis and the other based on machine learning, that determine which algorithm to use given the initial state of the perimeter defense game. We generated a large set of perimeter defense instances, simulated different solution approaches, and used the results to derive metareasoning policies. The analysis of the solution approaches and the basis for metareasoning to determine the solution approach were based on both the performance of the approach and the computation time taken. The results from our simulation study show that using these metareasoning policies leads, on average, to better solutions than existing algorithms used separately.
Cam-Shaped Soft Gripper With PVDF/Graphene Piezoelectric Sensor
Authors: Chen Liang-Chi , Chiou Jeng-Yu , Hsu Kuan-Lan , Huang Tsung-Han , Hung Wei-Song , Patel Brijesh , Lin Po Ting
Published: November 2024

In the era of growing integration of intelligent sensors in automated systems, propelled by advancements in industrial automation and the Internet of Things (IoT). This paper presents an innovative polyvinylidene difluoride (PVDF)/graphene piezoelectric membrane sensor specifically designed for direct force measurement. The remarkable properties of the piezoelectric material enable direct utilization without polarization. With a flexible design for easy installation at contact points between components, the sensor is tailored to the geometric shapes of components, finding application in soft grippers for object manipulation. The proposed novel piezoelectric sensor undergoes systematic evaluation through standardized experiments, obtaining measurements of different force magnitudes and corresponding voltage signal variations. The collected data is utilized to establish fitting models, thereby enhancing the reliability of the sensor’s data. The coefficient of determination (R squared) is employed as a metric to assess the goodness of fit of the models. Additionally, experimental results provide insights into the applicable range and voltage variations of the piezoelectric sensor. This research integrates a piezoelectric membrane sensor into an innovative cam-shaped soft gripper made of polydimethylsiloxane (PDMS) and demonstrates its application in agricultural automation by measuring the clamping force in plant seedlings. This cam-shaped gripper incorporates a novel self-alignment concept in its mechanism, enhancing its efficiency and mitigating potential damage to plant seedlings during the clamping process. Experiments with cam-shaped soft grippers demonstrate minimal deviation in gripping force.
Combining TRIZ and NLP to Identify Promising Problem-Solving Approaches for Emerging Technologies: A Preliminary Study
Authors: Bhattacharya Abhijeet , Mollan Calahan , Gupta Shreya , Pandey Vijitashwa
Published: November 2024

With the ever-expanding scope and increasing specialization of science research, more novel and niche issues are increasingly being addressed. This invariably leads to subfields developing to the point that they become independent areas of investigation by themselves. An example of such a phenomenon is the emergence of the many subareas stemming from the concept of Industry 4.0. All new such disciplines run into previously seen and unseen issues as they gain prominence and, as a result, practitioners. In this paper, we are focused on the ‘seen’ issues. Problem solving techniques, such as TRIZ, have enjoyed enormous success in engineering practice. The underlying premise behind TRIZ is that there is a small, finite number of methods which can be used to solve any problem and that most such problems have already been encountered and solved possibly in a different setting. Originally intended for physical inventions, TRIZ methods have since been applied to other fields such as patents to great effect. This paper uses natural language processing, machine learning, and abstracts from publicly available scientific articles to find if there exist common problem-solving methods in the engineering research of augmented and virtual reality, digital twins, and additive manufacture. We then present preliminary results and identify avenues for future research.
Techno-Economic and Environmental Impact Assessment of Phytomining for Extracting Rare Earth Elements in the Northwestern United States
Authors: Struhs Ethan , Mirkouei Amin
Published: November 2024

Demand for rare earth elements on a global scale is increasing daily due to the surging demand from various sectors (e.g., renewable energy and consumer electronics). Bio-ore, a product from pyrolysis conversion of biomass feedstocks obtained through phytomining, is a promising solution to address challenges faced by sustainable rare earth extraction, such as minimal land disturbance and soil erosion. This study explores the sustainability benefits of producing bio-ore at a critical materials rich site via a portable refinery unit and transporting it to an extraction plant. Techno-economic and environmental impact assessments are performed on a case study in the Northwestern United States. Total bio-ore production cost is estimated utilizing a life cycle costing model as part of the techno-economic analysis. Life cycle assessment is used to explore the global warming potential and other environmental impacts of the proposed bio-ore production pathway. Total cost of bio-ore production through phytomining ranges from $156–$197 per metric ton, depending on key parameters (e.g., mobile refinery capacity and hyperaccumulator water content). Total greenhouse gas emission is 11–35 kg CO2 eq. per metric ton of bio-ore. On-site production rate and biomass water content are the two key parameters that are examined in a sensitivity analysis to reduce bio-ore unit price and environmental impacts. This study concluded that the proposed phytomining-to-bio-ore approach provides a cost effective and economically feasible rare earth element extraction pathway.