bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influences of Engineering Student Backgrounds and Experiences on Conceptions of Product Design
Authors: Corby Adam , Hoffenson Steven , Pitterson Nicole 
Published: November 2022

Abstract
In undergraduate engineering programs, recent emphasis has been placed on a more holistic, interdisciplinary approach to engineering education. Some programs now teach product design within the context of the market, extending the curriculum to topics outside of scientific labs and computational analysis. This study analyzes survey and concept map data collected from 154 students in a third-year engineering design course. The aim is to evaluate the impacts of student backgrounds and experiences on their mental models of product design. Data were gathered from surveys on student backgrounds and experiences, along with concept maps that were generated by the students on the first day of a product design class. The concept maps were analyzed in a quantitative manner for structural and thematic elements. The findings show that several background attributes influence student conceptions of product design. Academic major appeared to have the largest impact on a variety of variables. Additionally, prior work experience, enrollment in a master’s program, and the presence of an engineering role model at home all showed significant impacts on design conceptions. By analyzing and understanding unique backgrounds of students, educators can adjust their curricula to more effectively teach design concepts to students of various backgrounds and experiences.
Effect of the Impact Coefficient of Restitution on the Nonlinear Dynamics Phenomenon of Flat-Faced Follower With Polydyne Cam Mechanism With Clearance
Authors: Yousuf Louay S. 
Published: November 2022

Abstract
The effect of impact coefficient of restitution on the nonlinear response of the follower is investigated at different follower guides’ clearances, different cam speeds and different followers’ offsets. The impact between the cam and the follower and between the follower and its guides are considered in the presence of coefficient of restitution and follower offset. The chaotic phenomenon of the follower due to the impact coefficient of restitution is detected by using phase-plane diagram. The numerical simulation of the nonlinear response of the follower is simulated using SolidWorks program. The chaotic phenomenon in cam follower system is increased with the increasing of impact coefficient of restitution value in which the potential energy of the follower has been decreased in the presence of follower offset. The chaotic motion of the follower response is occurred due to the increase in cam speeds, follower’s offsets, follower guides’ clearances and impact coefficient of restitution.
Identification of Motor Control Objectives in Human Locomotion via Multi-Objective Inverse Optimal Control
Authors: Tomasi Matilde , Artoni Alessio 
Published: November 2022

Abstract
Predictive simulations of human motion are a precious resource for a deeper understanding of the motor control policies encoded by the central nervous system. They also have profound implications for the design and control of assistive and rehabilitation devices, for ergonomics, as well as for surgical planning. However, the potential of state-of-the-art predictive approaches is not fully realized yet, making it difficult to draw convincing conclusions about the actual optimality principles underlying human walking. In the present study we propose a novel formulation of a bilevel, inverse optimal control strategy based on a full-body three-dimensional neuromusculoskeletal model. In the lower level, prediction of walking is formulated as a principled multi-objective optimal control problem based on a weighted Chebyshev metric, whereas the contributions of candidate control objectives are systematically and efficiently identified in the upper level. Our framework has proved to be effective in determining the contributions of the selected objectives and in reproducing salient features of human locomotion. Nonetheless, some deviations from the experimental kinematic and kinetic trajectories have emerged, suggesting directions for future research. The proposed framework can serve as an inverse optimal control platform for testing multiple optimality criteria, with the ultimate goal of learning the control objectives that best explain observed human motion.
Harnessing Operational Flexibility From Power to Hydrogen in a Grid-Tied Integrated Energy System
Authors: Rahman Jubeyer , Jacob Roshni Anna , Zhang Jie 
Published: November 2022

Abstract
Integrated energy systems (IES) are desirable in the power system due to their self-sufficiency and prompt response during critical operating conditions. In addition to reinforcing the system robustness, they are also capable of providing a number of ancillary services. Over the recent years, clean hydrogen has been explored as a promising solution to help the operation of a low-carbon grid. This work seeks to evaluate the benefits of integrating a hydrogen production facility into an IES infrastructure from the perspective of operation flexibility. Specifically, a grid-connected IES that consists of a small modular reactor (SMR), a wind farm, an electrolyzer that produces hydrogen, a fuel cell that converts hydrogen to electricity, and a hydrogen storage tank, is modeled and studied. The IES components are modeled considering their suitability for performing both power system unit commitment and economic dispatch simulations, and in this study we focus on day-ahead simulations. The proposed IES configuration aims to leverage the low-cost surplus generation (from SMR or wind) to produce hydrogen that could be used in peak load periods or traded in the hydrogen market. The results on the NREL 118-bus system simulation show that the IES could help reduce the total production cost and renewable curtailment in the system operation.
Dispersion Morphing in Highly-Reconfigurable Rotator Lattices
Authors: Fang Lezheng , Leamy Michael J. 
Published: November 2022

Abstract
We investigate wave propagation in in-plane rotator lattices and demonstrate dispersion morphing and extreme acoustoelastic effects using analytical and numerical means. By changing the angle of the rotator arms attaching the elastic linkage between adjacent rotators, we show that the band structure may morph from a positive/negative-group-velocity passband into a flat band across the whole wavenumber space, and then into a negative/positive-group-velocity passband. A similar process can also occur at certain fixed arm angles when the lattice constant changes, which one may interpret as stretching or compressing the structure along the lattice directions, effectively mimicking the acoustoelastic effect. We analytically investigate both processes and provide closed-form expressions for the occurrence of flat bands, which indicates the transition of the passband property. Further, we explore a chiral rotator lattice design where the oscillation equilibrium position for each rotator may shift upon the change of the lattice constant. This design has a unique advantage that the morphed passband maintains approximately the same frequency range such that a signal may stay propagating during the process of dispersion morphing. In the end, we present numerical simulations for three potential applications utilizing the aforementioned findings. In these applications, both static and dynamic lattice stretching are considered, resulting in on-demand bi-directional wave-guiding, refraction bending, and time-modulated amplifying. Numerical simulations document a high-quality agreement with theory and yield promising results that may inspire next-generation reconfigurable metamaterials.
Numerical Identification of Freedom Spaces Using the Canonical Basis
Authors: Archer Nigel , Hopkins Jonathan 
Published: November 2022

Abstract
In this paper, we introduce a complete set of numerical algorithms to find the principal twists of all freedom spaces given an arbitrary set of desired twists without explicitly constructing the reciprocal constraint space. Principal twists, sometimes referred to as the canonical basis, are the set of twists closest to being mutually orthogonal and reciprocal within the twist space. They can be used to categorize and identify freedom spaces by comparing their relative pitches and angles to that of the canonical forms for each space. The identification of freedom spaces (i.e., twist spaces) has been a central problem in screw theory since its conception. Until now, there has been no autonomous computational tool that can identify, locate, and orient a freedom space defined by any set of desired degree-of-freedom motions (i.e., twists). The authors are developing this tool as part of an Add-in for SolidWorks to guide users in designing compliant mechanisms via the freedom and constraint topologies (FACT) synthesis approach. The specific contributions of this paper, which were necessary to create this tool, are the following: (i) existing analytical methods are converted to complete numerical solutions, (ii) existing numerical tools are made more concise and efficient, (iii) new methods are derived to identify principal twists, and (iv) loose definitions within the field of screw theory are fortified.
A Novel Variable Stiffness Compliant Robotic Link Based on Discrete Variable Stiffness Units for Safe Human-Robot Interaction
Authors: Fu Jiaming , Lin Han , Xu Wei , Gan Dongming 
Published: November 2022

Abstract
Variable stiffness manipulators balance the trade-off between manipulation performance needing high stiffness and safe human-robot interaction desiring low stiffness. Variable stiffness compliant links provide a solution to enable this flexible manipulation function in human-robot co-working scenarios. In this paper, we propose a novel variable stiffness link based on discrete variable stiffness units (DSUs). A DSU is a parallel guided beam that can adjust stiffness discretely by changing the cross-sectional area properties of the hollow beam segments. The variable stiffness link (named Tri-DSU) consists of three tandem DSUs to achieve eight stiffness modes and a maximum stiffness change ratio of 31. To optimize the design, stiffness analysis of the DSU and Tri-DSU under various configurations and forces was performed by a derived theoretical model compared with finite element analysis (FEA). The analytical stiffness model is derived using the approach of serially connected beams and superposition combinations. It works not only for thin-walled flexure beams but also for general thick beam models. 3-D printed prototypes were built to verify the feature and performance of the Tri-DSU in comparison with the FEA and analytical model results. It’s demonstrated that our analytical model can accurately predict the stiffnesses of the DSU and Tri-DSU within a certain range of parameters. The developed variable stiffness link method and analytical model are extendable to multiple DSUs with different sizes and parameter configurations to achieve modularization and customization. The advantages of the stiffness change mechanism are rapid actuation, simple structure, and compact layout. These methods and results provide a new conceptual and theoretical basis for the development of new reconfigurable cobot manipulators, variable stiffness structures, and compliant mechanisms.
Iterations in Design and Development Process Illustrated Using Reconfigurable Robot Case Study
Authors: Leong Kristor J. K. , Hayat Abdullah Aamir , Yi Lim , Elara Mohan R. , Karthikeyan Elangovan 
Published: November 2022

Abstract
Iterations in design is ubiquitous to drive constant innovation in the pursuit of excellence in product development, service delivery, systems, and subsystems integration. Within a given time frame of a design process, iteration can occur at different scales, forms, types, etc. Iteration was highlighted recently in the innovation framework using the four ‘D’s design scheme, i.e., Discover, Define, Develop, and Deliver. Iteration studies generally focus on its occurrence, modeling, classification, methods, and impact, among others, in the domain of software development, service providing, aesthetics, and functionality. However, aspects of an iteration involving complex systems like a reconfigurable system become more intriguing because of its overall morphology with changing features and the coupled design of several subsystems. This paper reports on the various factors influencing iteration and are illustrated using a case study of the development of a reconfigurable robotic system named Panthera and its subsystems designed for cleaning and maintenance tasks. The case study of Panthera is reported from its initial ideation phase to the three versions development over a span of three years. Following the journey of the system design of Panthera, it details the timeline, rationale, and insight into the iterative processes and how they are applied to the individual subsystems in consecutive design iterations. With no one solution that fits all approaches to the topic, we aim to highlight and stimulate concepts to aid designers in the design iteration.
Modeling, Simulation and Analysis of a Variable Inertia Reaction Wheel Assisting Device
Authors: Okabe Eduardo P. , Brittes José Luiz P. , Miletto Daniel L. 
Published: November 2022

Abstract
Reaction wheels have been used in controlling the orientation of spacecraft and robots. They are particularly useful when there is not a solid foundation or track to support the motion. Tree pruning close to power lines is a risky activity that can lead to fatal accidents. The pole saw operator usually stays on top of a boom lift platform that is very bouncy and the space is very restricted. Using a reaction wheel to assist the motion of the pole saw can relief the human effort and make the operation faster. To improve the customization of the reaction wheel system a variable inertia rotor can be used, which can be adjusted to best fit the operation. The variable inertia is obtained by radially displacing the rotor segments thus increasing its moment of inertia. These segments are attached to the rotor hub through a set of springs and dampers. The rotor hub is driven by a reduction transmission attached to a brushless motor. This variable inertia reaction wheel system was modeled and simulated in two situations: kickback reaction and tree pruning. Although the system is composed by a single reaction wheel, the results showed that the system can help in both situations, reducing the effort up to 34%.
Examining a Trajectory of Complex System Design Processes: Airport Eco-System Case Studies by Novice Student Teams
Authors: Kim Euiyoung , Rao Vivek , Bluemink Bart , Klitsie Barend , Santema Sicco 
Published: November 2022

Abstract
As the aviation industry has become more complex and uncertain, we need to teach aviation topics with different pedagogical approaches: making the educational setting interdisciplinary and more design- and user-driven. We developed a design curriculum to address emerging complexity around air travel journeys and piloted the curriculum at a major research university in the Netherlands. Novice students in engineering, design, and social science programs in the Future of Airport minor on campus engaged in a quarter-long design course centered on the seamless air travel experience. The course aims to teach students how to approach the complexity of an airport and the stakeholders involved and design for people in transit. Data were collected from the results of work in document format (project progress reports and final deliverables) from thirty-five student teams who collaborated with aviation industry sponsors to develop solutions to address complex system-level industry design challenges. We classified the detailed project brief and outcomes by different innovation levels (product, service, system, or socio-technical), and examined the design methods implemented by each team over the design process. Our discussion is divided into (D1) trajectory of levels of innovation traveled during the project execution, (D2) descriptive reflection on overall selecting design methods, (D3) design method selection dynamics over design phases in complex problem domains, and (D4) challenges of offering a design approach to novice engineering students, drawn from the reflection by course coordinators and coaches on the course structure and contents.
A Neutrally Stable Quasi-Compliant Spherical Joint With a Remote Center of Rotation
Authors: Hogervorst Dion , Radaelli Giuseppe , Herder Just 
Published: November 2022

Abstract
This paper presents the design of a compliant spherical joint which is neutrally stable in two DoF and has a remote center of rotation. Such a joint can be used, for example, as an exoskeleton’s shoulder joint. The foundation of this paper lies in previous work that has succeeded in designing a compliant spherical joint with a remote center of rotation, but without neutral stability. The existing joint is simulated and its energy properties are analysed. Thereafter it is adapted and optimized for an axi-symmetrical energy field. A spring is introduced to the joint and optimized such that the combined energy field of both spring and joint, is neutrally stable. Experimental verification of the simulation was achieved with a prototype for which a moment reduction of 83.69% was achieved through the addition of the spring.
A Driving Simulator for UN157 Homologation Activities
Authors: Gobbi Massimiliano , Mastinu Gianpiero , Melzi Stefano , Previati Giorgio , Ronconi Luca , Sabbioni Edoardo 
Published: November 2022

Abstract
UN157 Regulation is devoted to the homologation of SAE Level 3 automated vehicles. The research and development activities related with the Regulation may require an extensive usage of driving simulators. Developing a sickness-free driving simulator is crucial for extensive tests to be performed with ordinary drivers.
The paper presents the technical features of the new driving simulator of the Politecnico di Milano. A number of biometric set of signals is recorded, namely, forces and moments at each single hand at the steering wheel, heart rate variability, skin resistance potential, eye movements. A matching of the objective monitoring of the driver is compared with the subjective psychological status. An initial population of 30 subjects has been investigated.
The new driving simulator has shown a good acceptance by ordinary drivers. Both objective and psychologic subjective assessment agree to state that the new driving simulator may be used to test ordinary driver behavior in a motorway scenario.
Modeling of the Weave and Wobble Eigenmodes of Motorcycles Using Flexible Multibody Simulation
Authors: Passigato Francesco , Gordner Achim , Diermeyer Frank 
Published: November 2022

Abstract
Weave and wobble are well known eigenmodes of motorcycles and have been studied by several authors because of their importance to the overall stability and safety of motorcycles. Studies have highlighted the importance of structural flexibility on these eigenmodes. A common approach in multibody simulationfor modeling the flexibility is the lumped stiffness method. It is advantageous for its limited modeling effort and its small impact on computational time. However, it was never demonstrated if this approach leads to sufficient accuracy when simulating the weave and wobble eigenmodes. The present work answers this question by modeling the structural components of a motorcycle with the flexible multibody approach. The most relevant components for the stability of weave and wobble are identified. A comparison with the lumped stiffness approach is also proposed. Moreover, some implementation details concerning models with flexible bodies are discussed.
Toward Generating System Architecture and Formal Functional Description in the Architecture Analysis & Design Language (AADL) With Structured Natural Language
Authors: Chauhan Anshumaan , Ganeriwala Parth , Sen Chiradeep , Bhattacharyya Siddhartha 
Published: November 2022

Abstract
Model based engineering has enabled automated analytical reasoning early in the design phase. As a result, inconsistencies and design errors can be captured early in the development lifecycle. But there is still a gap in the natural language-based specifications and its actual implementation. This is because the formal method-based tools utilize mathematical principles and theories of computation that require specific skills, thus reducing the usability of model-based engineering. Natural language is the most widely used method to represent specifications. So, it is intuitive to utilize natural language-based representation to generate system and formal annotations such that it will enable automated architectural analysis with much wider acceptance leading to a much broader impact. In our paper we focus on designing the above-mentioned approach that integrates representation of the specifications in a subset of English language which can then be used to generate system architecture in Architecture Analysis and Design Language along with the generation of functional specifications. We illustrate our approach by validating it with use cases from the aerospace and electromechanical domains.
Crankshaft Decoupling Effects on Fuel Economy in HEV-P0
Authors: Hegde Shailesh , Castellanos Molina Luis M. , Bonfitto Angelo , Galluzzi Renato , Amati Nicola , Tonoli Andrea 
Published: November 2022

Abstract
The increasingly stringent emission regulations have been one of the driving forces to explore more sustainable vehicle powertrains. On the one hand, carmakers are finding alternatives to meet these regulations; on the other hand, they are trying to improve smart features, such as chassis dynamics, passenger comfort, and, ride safety. The P0 architecture in a hybrid electric vehicle is a cost-effective layout due to its easy adaptation to the existing conventional vehicle architecture. In a P0 architecture, fuel consumption and emissions are increased when idling the engine during the stops to fulfill cabin air conditioning with the compressor. Thus, optimal energy management during these events would lead to an improvement in vehicle fuel economy. To this end, this work presents a novel configuration in a hybrid electric vehicle by installing an electromagnetic clutch between the internal combustion engine and the belt drive system. The objective of the study is to quantify the benefits of driving the air conditioning compressor with an electric machine under vehicle idle/stop conditions. It is demonstrated that the proposed solution improves the fuel economy as it shuts down the engine and decouples the engine resisting torque during stops. The results presented are simulated in the Worldwide harmonized Light vehicle Test Procedure homologation driving cycle and US06.