bluuebunny/crossref_metadata_2025_split huggingface dataset:
Subject-Specific Musculoskeletal Modeling of Adolescent Scoliosis Patients: a Pilot Study
Authors: Baus Juan , Cheng Zhiqing , Yang James 
Published: November 2023

Abstract
This paper presents developing and validating an algorithm-based protocol to build subject-specific musculoskeletal models using X-ray images and motion capture data. The MATLAB algorithm used bilateral X-ray images to determine the deviation angle of each vertebra in the frontal and sagittal planes and motion capture data to define the rest of the bone structure in a static posture. Previously validated musculoskeletal models were used as templates to avoid the necessity of scaling to each subject. Inverse kinematics and static optimization tools in OpenSim were used to define the joint angles and muscle activation for a scoliosis-specific exercise. Validation was done for the algorithm by comparing the vertebrae rotation angles with those obtained from a public database of scoliotic spine patients. The results showed that the Cobb angle deviation from the algorithm is smaller than the reported standard deviation for experimental measurements. Despite the successful simulation of muscle activation around the convex and concave sides of the scoliotic spine, future research could improve the protocol by including axial rotation of vertebrae and muscle scaling factors to enhance the individualization of each model. Nevertheless, the present protocol can create an individualized musculoskeletal model for a scoliosis patient.
Multi-Material and Multi-Joint Topology Optimization Considering Multiple Design Spaces
Authors: Kim Il Yong , Huang Yuhao , Crispo Luke 
Published: November 2023

Abstract
Today, automakers are focusing on cost reduction and lightweighting, by utilizing a combination of different materials in the vehicle design. Topology optimization is a numerical tool that provides more design freedom than other methods, such as size optimization and shape optimization. Multi-material topology optimization can optimize both material layout and material distribution to improve structural performance. However, these methods assume that dissimilar materials are perfectly bonded, which limits the manufacturability of the design. This work presents a multi-material and multi-joint topology optimization methodology that considers additional design variables for joints in the material interface region. The mechanical properties of joints are included in the analysis, which affects the overall structural behavior and the optimized result. This paper firstly introduces topology optimization methods and material interpolation functions for multiple design spaces. Then, the material interface region detection method is explained. After that, sensitivity analysis for different responses is conducted. Lastly, the results of some example models demonstrate this methodology can be used to control mass and joining cost in multiple design spaces within a structure.
Analytical Modeling and Validation of New Prismatic Compliant Joints Based on Zero Poisson’s Ratio Lattice Structures
Authors: Arredondo-Soto Mauricio , Cuan-Urquizo Enrique , Gómez-Espinosa Alfonso 
Published: November 2023

Abstract
Prismatic compliant joints have received limited attention compared to revolute compliant joints, thus limiting their implementation in compliant mechanisms. Lattice structures have been used effectively to increase flexibility and stiffness ratios in compliant joints. Considering these, new prismatic compliant joints based on zero Poisson’s ratio lattice structures (ZP-PCJ) are proposed. Lattices with three different cell arrangements are considered: single cells, 2 × 2, and 3 × 3 lattices. Additionally, unit cells with three different geometries are studied: triangular, chamfer, and cosine. The compliance matrices of the ZP-PCJs are assembled analytically using Castigliano’s second theorem and compliance series-parallel simplification. The compliance ratios along the three orthogonal axes of the ZP-PCJs are computed varying their geometric parameters. Finite Element models are constructed to validate the analytical results. Finally, experimental tests are performed on additively manufactured ZP-PCJs to corroborate the compliance coefficients. Results showed that analytical models can predict the ZP-PCJ’s elastic properties accurately, differences less than 3% and 15% were obtained when compared to computational and experiments, respectively. The ZP-PCJs have advantages such as eliminating axis drift and high flexibility in motion direction while maintaining stiffness in other directions due to their symmetric arrangements (with respect to the motion direction) and their zero Poisson’s ratio. The analytical models of ZP-PCJs derived, showed excellent agreement when compared with simulations and experimental results, making them a reliable option when aiming to estimate their performance in compliant systems.
Flank Modification Based on the Predetermined Contact Characteristics for Spiral Bevel and Hypoid Gears
Authors: Lee Yi-Hui , Chen Kuan-Hung , Fong Zhang-Hua 
Published: November 2023

Abstract
Spiral bevel and hypoid gears usually apply the flank modification with point contact to reduce gear running noise and avoid edge contact. This paper proposes the flank modification methodology based on the predetermined contact characteristics without the necessity of the tooth contact analysis. With the given gear member tooth surface, the conjugated pinion tooth surface can be derived by considering the mating gear as the cutter to roll with the work pinion. The center point of tooth-bearing is directly controlled, and the bias angle of the contact point path is designed based on the overlap ratio. Then, the flank modifications along the contact point path and the instantaneous contact lines are determined by the anticipated transmission errors and the elastic deformation as well as the length of the major axis of the contact ellipse. The generated tooth surface is approaching the modified flank by optimization. Additionally, the initial guesses for the optimization, such as the cutter parameters and the machine settings using the face-milling method, are calculated based on the theory of gearing and differential geometry. A numerical example of face-milled hypoid gear generated by the universal cradle-type generator is presented to demonstrate the validity of the proposed flank modification methodology.
Design of Mixed-Category Stochastic Microstructures: A Comparison of Curvature Functional-Based and Deep Generative Model-Based Methods
Authors: Xu Leidong , Naghavi Khanghah Kiarash , Xu Hongyi 
Published: November 2023

Abstract
Bridging the gaps among various categories of stochastic microstructures remains a challenge in the design representation of microstructural materials. Each microstructure category requires certain unique mathematical and statistical methods to define the design space (design representation). The design representation methods are usually incompatible between two different categories of stochastic microstructures. The common practice of pre-selecting the microstructure category and the associated design representation method before conducting rigorous computational design limits the design freedom and reduces the possibility of obtaining innovative microstructure designs. To overcome this issue, this paper proposes and compares two methods, the deep generative modeling-based method and the curvature functional-based method, to understand their pros and cons in designing mixed-category stochastic microstructures for desired properties. For the deep generative modeling-based method, the Variational Autoencoder is employed to generate an unstructured latent space as the design space. For the curvature functional-based method, the microstructure geometry is represented by curvature functionals, of which the functional parameters are employed as the microstructure design variables. Regressors of the microstructure design variables-property relationship are trained for microstructure design optimization. A comparative study is conducted to understand the relative merits of these two methods in terms of computational cost, continuous transition, design scalability, design diversity, dimensionality of the design space, interpretability of the statistical equivalency, and design performance.
Investigations on Ways to Improve the Scuffing and Wear Behaviour of Oil Free Water-Based Lubricants for Gear Applications
Authors: Barth Yves Johannes , Sagraloff Nadine , Egger Gregor , Tobie Thomas , Stahl Karsten 
Published: November 2023

Abstract
Today, mineral or synthetic oils that are made out of fossil raw materials, are the most common lubricants in gear drive applications. Most of them are non-biodegradable and may pose a risk to the environment. An important step to minimize the risk and the ecological footprint is the use of biodegradable and eco-friendly lubricants. Former research shows the potential of water-based lubricants in gear applications. Therefore, an oil-free, water-based lubricant, was developed for this study. The base lubricant contains plant-based thickeners to generate an appropriate viscosity for a sufficient lubricant film thickness in the tooth contact. In experimental investigations, the sliding wear and scuffing performance has been examined under variation of the added polymers and additives. The scuffing tests A/8.3/RT are performed acc. to DIN ISO 14635-1. The wear tests procedure is based on DGMK 377-01. In both scuffing tests with the sample the failure load stage = 8 was achieved. For case-carburized gears a “medium” to “high” amount of wear can be detected. Additional tests with nitrided gears show a “low” amount of wear. This paper aims to show the great potential of water-based oils for gear lubrication and suggests operating conditions for maximum wear and scuffing carrying capacity.
Design and Justice: A Scoping Review in Engineering Design
Authors: Syal Sita M. , Kramer Julia 
Published: November 2023

Abstract
Our society faces complex social justice challenges, often exacerbated by existing engineered products and technologies. Engineering designers play a critical role in creating and studying products and technologies that can both aim to solve and unintentionally contribute to social injustice. There is a growing priority in the engineering design research community to incorporate justice into design work and to do so meaningfully and intentionally. Therefore, there is a need to more deeply understand how scholars have integrated concepts of justice into their design work and to bring to light areas of future research. In this paper, we conduct a scoping review of design and justice in eleven scholarly venues relevant to the engineering design community. A scoping review allowed for a broad range of topics to be covered to identify major research themes and gaps, and to explore boundaries of the nascent study of design and justice. After searching the relevant venues, we conducted a thematic analysis to capture the major themes in the dataset of papers relating to justice and design. We found that scholars connected justice to their design work in ways that can be categorized into three main areas of design: Designers, Design Outcomes, and Design Process. Our analysis highlighted areas of future research in studying justice as relevant to Designers, Outcomes, and Processes, as well as identifying an overall call to redefine design as a whole in the pursuit of justice.
Design and Optimization of a Wearable Under-Actuated Mechanism for Spinal Posture Measurement
Authors: Hsu Ming-Chang , Chen Hsuan-Yu , Yeh Ting-Jen 
Published: November 2023

Abstract
This paper proposes a novel wearable device that can monitor the spinal posture. The proposed device adopts an underactuated mechanism design which allows it to adapt to the multiple-degrees-of-freedom spinal posture with minimum weight and complexity. To ensure the validity of measurement and comfort of wearing, the mechanism parameters are determined by an optimization algorithm so that uniform contact forces for selected spinal postures can be achieved. Experiments demonstrate that the device can automatically maintain contact with the wearer’s back and produce real-time spinal posture data for medical diagnosis and treatment.
On-the-Fly Dual Reduction Method on Transient Fluid Topology Optimization
Authors: Wang Tianye , Qian Xiaoping 
Published: November 2023

Abstract
Transient topology optimization (TO) requires huge computational resources in terms of both computing time and storage. In this study, we have applied the proper orthogonal decomposition (POD) based on-the-fly dual reduction method on TO problems for time-dependent incompressible fluid channel optimization. The fluid motion was governed by time-dependent Navier-Stokes equation. Total energy dissipation over a given period was considered as the cost function, and total fluid volume was constrained during optimization process. POD based reduced order modeling (ROM) was applied to both the primal equations and the adjoint equations for reduction. We examined the reduction efficacy though examples including U-bend channel and nozzle. Tolerance and snapshot set size were studied as hyper-parameters to improve the reduction performance. The best cases can reach 99% of skip ratios, 50% reduction in computational time, and 96% saving of memory storage.
Selection of Inverse Kinematics Solution Type for Cooperative Robots and Singularity Avoidance Based on Reinforcement Learning
Authors: Kato Daiki , Maeda Naoki , Takeuchi Ayumu , Sekioka Masataka , Hirogaki Toshiki , Aoyama Eiichi 
Published: November 2023

Abstract
In this study, we propose a method to avoid singularity by selecting solution types of inverse kinematics for a six-degree-of-freedom (6-DOF) manipulator based on reinforcement learning. A general 6-DOF manipulator has eight solution types of inverse kinematics for any position/posture of the end-effector. Owing to the complex structure of cooperative robots to prevent pinching during cooperative operations, inverse kinematics is often solved using numerical methods. Because the numerical solution depends on the initial values, it is difficult to select suitable solution types. According to the selection of the solution types, the robot may pass through a singularity, causing some joints to rotate rapidly. To avoid this, solution types must be selected considering the entire motion path of the robot. Therefore, we constructed Deep Q-Learning (DQN), a type of reinforcement learning, to select the solution types that minimize the angular velocity of each joint during the motion path. This was verified by a 6-DOF cooperative robot, where the robot was commanded to take a path through the singularity, and the solution types of inverse kinematics were selected by the DQN. Consequently, singularity was avoided by selecting suitable solution types, and the angular velocity was minimized.
Numerical Analysis and Wave Tank Test of a Point Absorber Wave Energy Converter Using a Tether Driven Power Take-Off System
Authors: Zhang Hu , Sun Liang , Liu Jingxuan , Mi Jia , Li Xiaofan , Xu Lin , Zuo Lei 
Published: November 2023

Abstract
Technologies to enhance the survivability of wave energy converters (WECs) in harsh ocean environment and reduce the difficulty and cost of deployment and operation are important. Traditional two-body point absorber with a rigid Power Take-off (PTO) may result in two essential problems on the deployment and operation. This study proposes a novel a two-body self-reactive point absorber with a flexible tether drive PTO. This flexible PTO design can avoid the request of supporting structures on the WEC to constrain the motion and harvest energy from multiple degree of freedoms (DOFs) motion without requirement of a taut mooring. System dynamics considering 4-DOF with the proposed flexible PTO system are formulated. A scaled prototype is designed, fabricated, and tested in a wave tank. Results show that the proposed flexible PTO can greatly increase the power absorption and add a reactive peak in the frequency domain. This study reveals that the proposed PTO is desirable for the two-body point absorber and thus holding the advantages of fast and easy deployment with slack mooring and good survivability under large wave conditions.
Print As a Dance Duet: Communication Strategies for Collision-Free Arm-Arm Coordination in Cooperative 3D Printing
Authors: Stone Ronnie F. P. , Zhou Wenchao , Akleman Ergun , Krishnamurthy Vinayak Raman , Sha Zhenghui 
Published: November 2023

Abstract
One of the major challenges in 3D printing is its lack of scalability both in size and speed, which directly impacts its economic feasibility for large-scale industrial applications. Cooperative 3D printing (C3DP) is an emerging paradigm that aims to address these issues by employing multiple mobile printers that work in parallel. However, a crucial step in enabling C3DP is the development of a collision-free communication framework between the printers during the manufacturing process. Many C3DP systems found in the literature develop solutions for collision-free printing that are specific to the setup being used, thus not allowing the solution to be transferred to other similar systems. In this paper, we formulate a general framework that generates four distinct collision-free communication strategies to enable arm-arm coordination for C3DP using robotic manipulators. We considered collisions both between the arms with themselves and between the arms and the part being printed. The strategies are general in that they are agnostic to the number of printers, their kinematics, and their spatial configurations in the manufacturing environment. We conducted a study of the four strategies using a two-printer scenario and then physically validated them with four test cases of varying geometries. The results show that the strategies successfully produce printed parts while being collision-free. The makespan reduction using our strategies when compared to a single printer varied from 20% to 42% depending on the strategy used. Finally, we discuss the limitations of the framework, as well as future research directions.
Defining and Modeling of Height-Related Geometrical Parameters for Thin Wall Structures Manufactured by Metal Additive Manufacturing
Authors: Rahmani Dehaghani Mostafa , Tang Yifan , Panicker Suraj , Wu Di , Coatanea Eric , Wang G. Gary 
Published: November 2023

Abstract
Cold metal transfer wire and arc additive manufacturing (CMT-WAAM) is a type of metal additive manufacturing technology that has attracted attention in recent years due to its ability to print walls with less dimensional inaccuracies than regular WAAM. To print near net shape parts by CMT-WAAM, there is a need to define a set of height-related geometrical parameters (HGPs) that can capture, quantify, and compare the quality of the height of the produced parts. In this study, a set of HGPs, namely, the average height error (AHE), maximum height variation (MHV), and average absolute slope (AAS) are defined and assessed. Fifteen single-track multi-layer walls are printed to check the effect of process parameters on the defined HGPs. It is found that the stability of the print cannot be guaranteed by checking the visual appearance of the single beads and at least five-to-ten-layer walls should be printed to check the quality and stability of the print. It is also found that the travel speed (TS) and wire feed speed (WFS) have positive monotonic relationships with AAS and MHV, respectively. Correlations between process parameters and HGPs are modeled and validation tests are performed to check the validity of the developed models. The defined three HGPs are shown to be able to quantify, capture, and compare the quality of a height of a wall and can be used for other similar applications.
Testing and Validation of a Mobile Damping Robot for Power Lines
Authors: Choi Andrew , Barry Oumar 
Published: November 2023

Abstract
Fixed passive vibration absorbers (FPVAs) are widely used on power lines and other continuous systems, but they are inherently limited since changes in wind conditions affect absorber performance due to changing mode shapes. A mobile damping robot (MDR) can overcome these limitations by actively transporting a passive absorber to conductor antinodes where the absorbers can most effectively remove energy from the system. While many analyses have been performed for fixed masses on power line conductors, they have not been in the context of interactions between the conductor and a mobile damping robot (MDR). There is a need to explore the potential impact of the MDR on the power line and the resulting implications for the MDR’s development as current methods of vibration control do not adequately address fatigue failure caused by wind-induced vibrations (WIV). In this paper, we define a mathematical model of the system and perform numerical analysis in MATLAB® using equations of motion obtained via Hamilton’s Principle. We investigate the adequacy of an experimental test bench for testing. Then we experimentally validate the ability of a mobile robot to transport a mass along a conductor to antinode locations. Experimental results indicate that the robot is able to navigate to the locations of highest amplitude on the cable. The insights gained from this work lay a foundation to guide future experiments that will better define the operating conditions of the MDR and lead to the creation of an appropriate control framework.
Localisation of Mobile Robots via Ultra-Wideband Systems
Authors: Neri Federico , Annoni Luca Alfredo , Palmieri Giacomo , Palpacelli Matteo-Claudio , Callegari Massimo 
Published: November 2023

Abstract
This paper presents an innovative solution that allows an autonomous mobile robot (AMR) to locate itself in space via UWB nodes. This reduces the possibility of error caused by the modularity of warehouses and makes it possible to send variable missions based on the data received. To this end, it was decided to use ultra-wideband (UWB) nodes, which allow to calculate the spatial coordinates of a reference tag with respect to the robot. Using this approach, material was taken from a storage facility and loaded on board using an anthropomorphic arm positioned on the mobile robot. Subsequently, other reference tags are used to locate a mobile truck equipped with a loading platform. In this way, a mission can be sent to the mobile robot to get on the truck and be transported to another work area. The article describes the advantages and difficulties of this localisation methodology and shows how tests were carried out to verify its functioning. The study is part of eMOBOTS (electric mobility robot & shuttle), a project that aims to develop mobility solutions for the smart factory developed by TEKNE srl, the Department of Industrial Engineering and Mathematical Sciences, Polytechnic University of Marche and the company Joytek.