bluuebunny/crossref_metadata_2025_split huggingface dataset:
Automated Classification of Components for Manufacturing Planning: Single-View Convolutional Neural Network for Global Shape Identification
Authors: Barclay Andrew , Corney Jonathan 
Published: November 2020

Abstract
An experienced engineer can glance at a component and suggest appropriate methods for its manufacture. This skill has been difficult to automate but in recent years Neural Networks have demonstrated impressive image recognition capabilities in many applications. Consequently, this work is motivated by the goal of automating shape assessment for manufacturing. Specifically the reported work investigates the feasibility of training a convolutional neural network (CNN) to recognize 2D images of shapes associated with particular Near Net Shape (NNS) manufacturing processes such as casting, forging, or flow forming. The system uses multiple images generated from 3D CAD models (each manually associated with specific NNS processes) as training data and a single shop floor photograph as a classification query. While multiple views are used to train the CNN only a single view is used to assess the accuracy of the classification. Such single-view classification is designed to support the easy assessment of physical parts observed in manufacturing facilities where it would often be impractical to create an array of images from many viewpoints. The result suggests that despite limitations, single-view CNNs can classify real engineering components for manufacture.
A Novel Bi-Stable Piezoelectric Energy Harvester Inspired by the Venus Flytrap
Authors: Qian Feng , Zuo Lei 
Published: November 2020

Abstract
This paper studies the nonlinear dynamics and energy harvesting performance of a novel bi-stable piezoelectric energy harvester inspired by the rapid shape transition of the Venus flytrap leaves. The harvester is composed of a piezoelectric MFC transducer, a tip mass, and two sub-beams. The two sub-beams are akin to the bidirectionally curved Venus flytrap leaves that could rapidly snap-through from the open state to the closed state. To realize the bistability of the Venus flytrap leaves induced by the stored potential energy, an in-plane pre-displacement constraint is applied to the free ends of the sub-beams. The pre-displacement constraint leads to bending and twisting deformations and creates the potential energy in the harvester. The bio-inspired design is introduced in detail and a prototype is fabricated to validate the conceptual design. The nonlinear dynamics of the bio-inspired bi-stable piezoelectric energy harvester is investigated under base acceleration excitations. Results show that the sub-beams of the harvester experience more complicated local vibrations containing broadband high-frequency components as the snap-through motion happens. The energy harvesting performance of the harvester is evaluated at different excitation levels. The broadband energy harvesting is achieved at higher excitation levels and an average power output of 0.193 mW is attained under the excitation of 10 Hz and 4.0 g.
Static Balancing of Four-Bar Linkages With Torsion Springs by Exerting Negative Stiffness Using Linear Spring at the Instant Center of Rotation
Authors: Franco Jorge A. , Gallego Juan A. , Herder Just L. 
Published: November 2020

Abstract
A design approach for the quasi-static balancing of four-bar linkages with torsion springs is proposed. Such approach is useful on the design of statically balanced compliant mechanisms by setting the stiffness of the Pseudo-Rigid-Body-Model. Here the positive stiffness exhibited by torsion springs at the R-joints is compensated by a negative stiffness function. The negative stiffness is created by a non-zero-free-length linear spring connected between the coupler link and the ground, and where both connecting points trace a line directed to the coupler link’s instant center of rotation. An example of the static balancing of the Burmester’s linkage for straight path generation is developed, where actuation energy is reduced in 94% for a range of motion of 80 degrees for the input link.
Triple-Cell Origami Structure for Multistable Transition Sequences
Authors: Liu Zuolin , Fang Hongbin , Xu Jian , Wang K. W. 
Published: November 2020

Abstract
With the infinite design space and the excellent folding-induced deformability, origami has been recognized as an effective tool for developing reconfigurable structures. Particularly, the multistable origami structure, which possesses more than one stable configuration that is distinct in shape and mechanical properties, has received wide research attention. Generally, the origami structure reaches a kinematic singularity point when switching among different stable configurations. At this critical state, multiple switching sequences are possible, and the actual transition is generally hard to predict. In this paper, evolving from the conventional bistable Miura-ori unit, a triple-cell origami structure with eight potential stable configurations is proposed, which serves as a platform for investigating the transition sequences among different stable configurations. To quantify the overall elastic potential of the structure, besides the conventional elastic energy originating from the rigid folding creases, extra elastic potential induced by the mismatch among the cells are introduced, so that folding of the triple-cell structure is no longer a strict single degree-of-freedom mechanism. Instead, the three cells can deform asynchronously to avoid reaching the kinematic singularity point. Hence, under displacement loading, the transition sequence of the multistable structure is predicted by performing optimization on the elastic potential energy. It shows that sequences with multifarious characteristics are possible, including reversible and irreversible transitions, and transitions with symmetric and asymmetric energy barriers. Considering that the fundamental transition mechanisms are of great significance in understanding the quasi-static and dynamic behaviors of multistable structures, the results could be potentially employed for developing morphing structures, adaptive metamaterials, and mechanical logic gates.
A Framework for a Motorcycle Design Computer-Based Intelligent Tool
Authors: Agius Sean , Farrugia Philip , Francalanza Emmanuel 
Published: November 2020

Abstract
Motorcycle riders’ road experience, attitude and position have a large impact on safety. Besides these aspects, a motorcycle designer has to consider the aesthetical emotional value of such artefacts. This paper contributes a novel framework architecture supports designers to develop a rider-centred, safer motorcycle design, while at the same time considering human factors and the emotional values of such artefacts. This paper explores the requirements for this framework through a validated mixed method approach, gaining input from interviewed designers, stakeholders as well as surveyed riders. The proposed framework takes a user-centred approach, placing designers and riders at the framework’s core. Riders are an essential aspect as they assist in generating the knowledge which is critical to the operation of the framework. The framework acts as a support to the motorcycle designer, where it couples the intellectual resources of the designer with the knowledge capabilities of the framework to proactively support motorcycle design decision making. The proposed framework is driven by a harmonisation engine, where the aesthetic, ergonomic, persona and market trend domains are harmonised to achieve a balanced motorcycle design solution. The framework architecture will be employed to implement an intelligent computer-based motorcycle design support tool, in future work.
Passive Mechanical Metamaterial Sensor and Actuator
Authors: Waheed U. , Myant C. 
Published: November 2020

Abstract
In recent years, and with the continual development of additive manufacturing technologies, mechanical metamaterials have been explored for their programmable nature. This has opened a new design space into devices using functional materials. In this paper, a novel mechanical metamaterial device is designed, combining anisotropic 3D unit cells to slender beams. By controlling the separation distance between the fixed ends of a slender beam, the mechanism can be tuned to transition between monostable and bistable states. This behaves as a sensor and actuator, allowing mechanical signals to pass only when the correct actuation pattern is received. The device is shown to be inherently passive as it returns to a monostable state after actuation. Two different designs have successfully demonstrated this repeatable behaviour. A multi-material PolyJet printed mechanism joining unit cells to a Von Mises Truss, and an SLA printed compliant mechanism coupling unit cells to thin slender beams. A novel approach in performing AND/OR mechanical logic has also been successfully demonstrated by manipulating the mechanical metamaterial when in a bias state. The proposed devices have application in soft robotic systems, the aerospace industry and in the nuclear sector, where there is a need for passive safety systems that are not reliant on electronic systems, and respond to environmental stimuli. The printed mechanisms highlight the potential for mechanical metamaterials to be used as tunable sensors and actuators for future engineering applications.
Building Block Based Topology Synthesis Algorithm to Optimize the Natural Frequency in Large Stroke Flexure Mechanisms
Authors: Fix Mathijs E. , Brouwer Dannis M. , Aarts Ronald G. K. M. 
Published: November 2020

Abstract
Flexure based compliant mechanisms suited for a large range of motion can be designed by handling the challenges arising from combining low compliance in the desired directions, high support stiffness, low stresses and high unwanted natural frequencies. Current topology optimization tools typically can’t model large deflections of flexures, are too conceptual or are case specific. In this research, a new spatial topological synthesis algorithm based on building blocks is proposed to optimize the performance of an initial design. The algorithm consists of successive shape optimizations and layout syntheses. In each shape optimization the dimensions for some layout are optimized. The layout synthesis strategically replaces the most “critical” building block with a better option. To maximize the first unwanted natural frequency the replacement strategy depends the strain energy distribution of the accompanying mode shape. The algorithm is tested for the design of a 1-DOF flexure hinge. The obtained final layout agrees with results known from literature.
On the Nonlinear Mode-Coupling in Ultra Precision Manufacturing Machines: Experimental and Analytical Analyses
Authors: Gupta Sunit K. , Bukhari Mohammad A. , Barry Oumar R. , Okwudire Chinedum E. 
Published: November 2020

Abstract
Recent studies in passively-isolated systems have shown that mode coupling is desirable for best vibration suppression, thus refuting the long-standing rule of mode decoupling. However, these studies have ignored the non-linearities in the isolators. In this work, we consider stiffness nonlinearity from pneumatic isolators and study the nonlinear free undamped vibrations of a passively-isolated ultra-precision manufacturing (UPM) machine. Experimental analysis is conducted to guide the mathematical formulation. The system comprises linearly and nonlinearly coupled in-plane horizontal and rotational motion of the UPM machine with quadratic nonlinear stiffness from the isolators. We present closed-form expressions using the method of multiple scales for two cases viz. the non-resonant case and the bounded internal resonance case. We validate our theoretical findings through direct numerical simulations. For the non-resonant case, we show that the system behaves similar to a linear system. However, for the nearly internal resonance case, we demonstrate strong energy exchange between the modes stemming from nonlinear mode coupling. We further study the effect of nonlinear mode coupling on the vibration isolation performance and demonstrate that mode coupling is not always desirable.
Generative Adversarial Networks With Synthetic Training Data for Enforcing Manufacturing Constraints on Topology Optimization
Authors: Greminger Michael 
Published: November 2020

Abstract
Topology optimization is a powerful tool to generate mechanical designs that use minimal mass to achieve their function. However, the designs obtained using topology optimization are often not manufacturable using a given manufacturing process. There exist some modifications to the traditional topology optimization algorithm that are able to impose manufacturing constraints for a limited set of manufacturing methods. These approaches have the drawback that they are often based on heuristics to obtain the manufacturability constraint and thus cannot be applied generally to multiple manufacturing methods. In order to create a general approach to imposing manufacturing constraints on topology optimization, generative adversarial networks (GANs) are used. GANs have the capability to produce samples from a distribution defined by training data. In this work, the GAN is trained by generating synthetic 3D voxel training data that represent the distribution of designs that can be created by a particular manufacturing method. Once trained, the GAN forms a mapping from a latent vector space to the space of manufacturable designs. The topology optimization is then performed on the latent vector space ensuring that the design obtained is manufacturable. The effectiveness of this approach is demonstrated by training a GAN on designs intended to be manufacturable on a 3-axis computer numerically controlled (CNC) milling machine.
Exploratory Assessment of Design Entrepreneurial Program New Venture Design Experience to Prune Program Activities
Authors: Lugo José E. , Muñoz-Soto Adriana M. , Ríos-Torres Manuel O. 
Published: November 2020

Abstract
The purpose of this paper is to explore the activities of the New Venture Design Experience (NVDE), an entrepreneurial program with an engineering design and marketing focus, and recommend which activities the students report more useful. Currently the entrepreneurial program synchronizes four courses between engineering and business school over the period of two semesters. All courses are to various degrees co-taught. The campus entrepreneurial ecosystem has extracurricular activities that can supplement and or substitute some of the NVDE activities. To explore the impact of entrepreneurial activities (NVDE or ecosystem) a semi-structure interview was designed to uncover which activities were more valuable for the students after the program. For this, fourteen former students from NVDE were interviewed, seven already graduated and seven are still undergraduate students. Initial recommendations are provided towards which activities to scale down.
An Adapted Ethnographic Approach to Social Cognition and Cognitive Apprenticeship in Design Learning Experience
Authors: Milojevic Hristina , Jin Yan , Patel Ananya , Chastain-Howley Perri , Brown Noah K. 
Published: November 2020

Abstract
Design is difficult to teach in traditional ways of lecturing and testing. One defined learning methodology that applies well to design education is project-based learning. In an attempt to better understand the patterns of project-based learning in different design-related programs, we studied three small groups of teachers and students at an innovative academy based out of Shanghai Institute of Visual Art, entitled De Tao Master’s Academy, and compared their education style to that of subjects in regular programs at Shanghai Institute of Visual Art. Our goal was to seek patterns of cognitive apprenticeship in our subjects’ education, and find out (a) if it’s more effective than the traditional approach, and (b) can modelling (i.e. direct replication of learned material) be excluded from a design curriculum.
The information gathered through surveys, interviews and observation were segmented into six categories: (1) self-regulation, (2) creative thinking and thinking styles, (3) incorporation of cognitive apprenticeship model into teaching style, (4) teaching hours vs. self-learning, (5) individual vs. team work preference, and (6) learning environment and teaching resources.
We found that self-regulation was uniformly low throughout the sample, but that De Tao curriculum aimed to increase it over the course of their programs. Most students preferred small teams, with less than 5 students to do assignments and projects with, instead of individually working or working in large teams. Curriculum and interviews indicated De Tao programs had a higher focus on teaching creative thinking and independence, which reflected on design self-efficacy scores of their students when compared with SIVA students. Learning spaces at De Tao were observed to be better, and their instruction constructed close to cognitive apprenticeship. Coaching, scaffolding, articulation and exploration were evident in the design education methods adopted at De Tao. The ethnographic findings were related into an evolved social cognitive design framework, which allowed us to preliminarily contextualize design learning influencers.
Medical Assessment Test of Extrapersonal Neglect Using Virtual Reality: A Preliminary Study
Authors: Lanzoni Daniel , Vitali Andrea , Regazzoni Daniele , Rizzi Caterina 
Published: November 2020

Abstract
The research work presents a preliminary study to create a virtual reality platform for the medical assessment of spatial extrapersonal neglect, a syndrome affecting human awareness of a hemi-space that may be caused by cerebral lesions. Nowadays, the extrapersonal neglect is assessed by using real objects positioned in the space around the patient, with a poor capability of repetition and data gathering. Therefore, the aim of this research work is the introduction of a virtual reality solution based on consumer technology for the assessment of the extrapersonal neglect. By starting from the needs of the involved medical personnel, an online serious-game platform has been developed, which permits to perform a test and a real-time evaluation by means of objective data tracked by exploited technologies, i.e. an HTC Vive Pro head mounted display and ad-hoc IT solutions. The test is based on a virtual environment composed by a table on which twenty objects have been placed, ten on the right side and ten on the left side. The whole 3D virtual environment has been developed using low-cost and free development tools, such as Unity and Blender.
The interaction with the virtual environment is based on voice recognition technology, therefore the patient interact with the application by pronouncing the name of each object aloud. The VR application has been developed according to an online gaming software architecture, which permits to share the 3D scene by exploiting a Wi-Fi hotspot network. Furthermore, the on-line gaming software architecture allows sending and receiving data between the doctor’s laptop and the VR system used by the patient on another laptop. The therapist can see through his/her personal computer a real time faithful replica of the test performed by the patient in order to have a fast feedback on patient’s field of view orientation during the evaluation of 3D objects.
A preliminary test has been carried out to evaluate the ease of use for medical personnel of the developed VR platform. The big amount of recorded data and the possibility to manage the selection of objects when the voice commands are not correctly interpreted has been greatly appreciated. The review of the performed test represents for doctors the possibility of objectively reconstructing the improvements of patients during the whole period of the rehabilitation process. Medical feedback highlighted how the developed prototype can already be tested involving patients and thus, a procedure for enrolling a group of patients has been planned. Finally, future tests have been planned to compare the developed solution with the Caterine Bergero Scale to define a future standardization.
Investigating How Additively Manufactured Parts in Traditionally Manufactured Systems Affect the System Dynamic Properties
Authors: Funke Lawrence , Hylton Blake , Brown Kyle , Sommer Mallory 
Published: November 2020

Abstract
Additive manufacturing (AM) sits poised to make a large impact on the manufacturing sector. Expanding from their original application in rapid prototyping, AM parts are increasingly appearing in full production systems. Using AM parts as replacement parts has recently been touted as a way to save money and increase efficiencies in supply chains. While much work has been done exploring the properties of individual AM parts and how they might affect supply chains, very little has been done to investigate the impact of AM parts as components in a larger system. In fact, there appears to be a lack of research into how AM components affect the system vibrational properties when used as replacement parts. This work sought to answer this question by investigating the effects of replacing a steel bar in a four-bar mechanism with an AM polylactic acid (PLA) bar. Both static and dynamic testing were performed on the system when it was entirely steel, and when one part was replaced with an AM PLA bar. The static results indicated that the dominant modal frequencies of the system were not significantly impacted by the change, possibly suggesting that AM components may be used as replacement parts without concern for shifting modes of vibration. The dynamic data showed that the reduction of mass in the link helped reduce vibrations during operation, suggesting that some care should be taken in matching part properties between AM components and the ones they are replacing. The authors do urge caution in applying and interpreting these results, though, as they are preliminary and require further investigation. Because of this, the paper concludes with suggestions on how to expand and extend these results to fill the gap in the literature identified herein.
A Cable-Driven Parallel Robot With Full-Circle End-Effector Rotations
Authors: Métillon Marceau , Lessanibahri Saman , Cardou Philippe , Subrin Kévin , Caro Stéphane 
Published: November 2020

Abstract
Cable-Driven Parallel Robots (CDPRs) offer high payload capacities, large translational workspace and high dynamic performances. The rigid base frame of the CDPR is connected in parallel to the moving platform using cables. However, their orientation workspace is usually limited due to cable/cable and cable/moving platform collisions. This paper deals with the designing, modelling and prototyping of a hybrid robot. This robot, which is composed of a CDPR mounted in series with a Parallel Spherical Wrist (PSW), has both a large translational workspace and an unlimited orientation workspace. It should be noted that the six degrees of freedom (DOFs) motions of the moving platform of the CDPR, namely, the base of the PSW, and the three-DOFs motion of the PSW are actuated by means of eight actuators fixed to the base. As a consequence, the overall system is underactuated and its total mass and inertia in motion is reduced.