bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modeling Torque Converter Characteristics in Automatic Drivelines: Lock-up Clutch and Engine Braking Simulation
Authors: Adibi Asl Hadi , Lashgarian Azad Nasser , McPhee John 
Published: September 2013

A torque converter, which is a hydrodynamic clutch in automatic transmissions, transmits power from the engine shaft to the transmission shaft either by dynamically multiplying the engine torque or by rigidly coupling the engine and transmission shafts. The torque converter is a critical element in the automatic driveline, and it affects the vehicle’s fuel consumption and longitudinal dynamics.
This paper presents a math-based torque converter model that is able to capture both transient and steady-state characteristics. The torque converter is connected to a mean-value engine model, transmission model, and longitudinal dynamics model in the MapleSim environment, which uses the advantages of an acausal modeling approach. A lock-up clutch is added to the torque converter model to improve the efficiency of the powertrain in higher gear ratios, and its effect on the vehicle longitudinal dynamics (forward velocity and acceleration) is studied.
We show that the proposed model can capture the transition from the forward flow to the reverse flow operations during engine braking or coasting. The simulation results also show that the engine braking phenomenon (due to the flow reversal) can effectively assist the braking system to slow down the vehicle.
The Generation of Machining Process Plans Using a Haptic Virtual Reality System
Authors: Fletcher C. A. , Ritchie J. M. , Lim T. 
Published: September 2013

Computer Aided Process Planning (CAPP) links the design and manufacture of a machined product defining how the product itself will be manufactured. Decisions made during this phase can have a significant impact on product cost, quality and build time; therefore, it is important that process planners have intuitive tools to aid them in effectively creating process plans. However, in spite of being a strong research area, the actual application of CAPP systems in industry is limited and new modern 3D digital tools in this area have not been researched to any real degree.
Traditional process planning is carried out either manually or via a CAPP interface and, from this activity, a set of instructions are generated for the shop floor. However, these CAPP processes can be time consuming and subject to inconsistencies. Current research seeks to automate the generation of work instructions by using previous designs and/or artificial intelligence. However, due to the complexity of manufacturing a wide range of products, the limited range of tools available and differing skills of the workforce, it is difficult to reach a generic solution for practical application.
The novel pilot study given in this paper presents one of the first pieces of research comparing and contrasting a traditional manual approach to machined part process planning with an alternative haptic virtual environment. Within this, an operator can simulate the machining of a simple part using a virtual drilling and milling process via a haptic routing interface. All of the operator input is logged in the background with the system automatically generating shop floor instructions from this log file.
Findings show that users found the virtual system to be more intuitive and required less mental workload than traditional manual methods. Also their perceptions for the future were that they would need less support for learning and would progress to final planning solutions more quickly.
An Adaptive Weighting Strategy for Multi-Load Topology Optimization
Authors: Suresh Krishnan , Ramani Anand , Kaushik Anshul 
Published: September 2013

In this paper, we consider topology optimization of continuum structures subject to multiple loads. The objective is to minimize mass, while satisfying maximum displacement constraints at the points of load-application.
The classic method of including displacement constraints is through penalization of the objective function. Here, we propose an alternate method that relies on the concept of topological sensitivity. The proposed method generalizes the recently proposed single-load PareTO method by the first author. For multi-load problems, the topological sensitivity fields for each of the load-cases are computed, and then combined through weighting functions that continuously adapt to satisfy the constraints. Different weighting functions are considered, and compared through numerical experiments.
Bipedal Walking Robot Driven by Elastic Cables
Authors: Kljuno Elvedin , Williams Robert L. , Zhu Jim 
Published: September 2013

This paper presents a design concept and analysis of a bipedal walking robot with a novel type of actuation using elastic cables. Each leg has 6-dof, the trunk has 3-dof, and each arm has 1-shoulder-dof. Conventional walking robots consist of joint-attached drives at revolute joints. This yields relatively heavy legs and arms with high moments of inertia, which makes balancing robot dynamic walking difficult due to the high inertial forces of distal segments.
The cable-based actuation system is designed for the most kinetically-active biped segments, such as lower legs. These consist of DC motors located on the trunk, elastic cables (with serially-connected springs) and cable routing with specially-designed pulleys. Since the trunk segment accelerations are significantly lower than the leg segments accelerations, it is expected that the overall energy required by the cable-actuated robot is significantly lower than the energy input to a directly-actuated biped.
Another novelty in the biped actuation system design is the use of elastic rather than non-elastic cables, for two reasons: smoothing out the sharp impulses due to the foot-ground collision and reduction of the number of motors to actuate each joint. Non-elastic cable-based drives require each cable to be pulled by a separate motor, which would double the number of motors and increase the weight. This problem can be solved using elastic cables and specially-shaped pulleys to reduce the number of motors with a slight increase in controller complexity.
The bipedal walking robot architecture with cable drives mimics the human body architecture, where the hip joint is a 3-dof spherical joint, 1-dof knee joint, and 2-dof ankle joint. The architecture is more compact compared to the conventional joint attached drive architecture, wherein all revolute joints are separated.
Based on the kinematic and dynamic analysis of the robot, a controller is designed and the perturbation robustness tested. A feedback linearization controller design is used, requiring system dynamics knowledge. Steps toward hardware implementation have been made, since we have implemented an elastic cable actuation system on a robotic cat prior to the concept design for the bipedal robot. The difficulties are discussed, including future plans for improvements and hardware testing.
Virtual Reality Providing Ground Truth for Machine Learning and Programming by Demonstration
Authors: Roßmann Jürgen , Schlette Christian , Wantia Nils 
Published: September 2013

In this contribution, it is demonstrated how the development, parameterization and evaluation of an intelligent cognitive system can be supported by means of Virtual Reality (VR). Based on new approaches in object and action recognition, the consortium in the EU funded project IntellAct is developing such an automated system for the intelligent understanding of manual tasks and robot-based manipulations.
In this context, the VR setup of the Institute for Man-Machine Interaction (MMI) is able to deliver ideal data, such as detailed positions and joint data of objects and kinematics involved. In addition, it allows for the synthesis of distinct and error-free data, such as collisions, bounding boxes and contact events. This way, Virtual Reality serves as a reference and source for “ground truth” data for designing, training and benchmarking the intelligent cognitive system during its development and parameterization. Furthermore this approach enables descriptive and secure ways for the visualization of results in the targeted environments, such as the highly automated laboratories on-board the International Space Station (see Fig. 1).
A Frame-Independent Vector Expression of the Singularity Locus of the Gough-Stewart Platform
Authors: Doyon Karine , Gosselin Clément , Cardou Philippe 
Published: September 2013

This paper presents a vector expression of the singularity locus of the Gough-Stewart platform. In order to obtain this expression, several algebraic operations are performed on the manipulator’s Jacobian matrix such as relocating the origin of the reference frame and linearly combining columns. The third-degree vector expression thus obtained does not contain a constant term, which allows the factorization of an instance of the position vector. An alternative notation that reduces the number of times that the position vector appears in the expression is then presented. It is also demonstrated that a simplified architecture such as that of the MSSM can significantly reduce the length of the expression.
Finally, some numerical examples of singularity loci are presented, which were estimated by combining the proposed formulation with interval analysis in the cases of a generic Gough-Stewart platform and of an MSSM. The results obtained illustrate how the precision of interval analyses are influenced by the form of the symbolic expression of the singularity locus.
Towards a Comprehensive Test of Qualitative Reasoning Skill in Design
Authors: Khorshidi Maryam , Woodward Jay , Shah Jami J. 
Published: September 2013

A battery of tests for assessing the cognitive skills needed for the conceptual design is being developed. Divergent thinking and visual thinking tests were fully developed and validated previously. This paper focuses on the development of a test on qualitative reasoning skill.
Indicators of qualitative reasoning are identified and categorized as: deductive reasoning, inductive reasoning, analogical reasoning, abductive reasoning, and intuitive physics; the derivation of each is based on both cognitive science and empirical studies of design. The paper also considers the metrics for measuring skill levels in different individuals and candidate test items and grading rubric for each skill.
Camera Calibration Method for Accurate Full-Field Strain Measurement by Dot Centroid Method
Authors: Toyoshi Takuya , Wada Yoshitaka , Furukawa Tomonari 
Published: September 2013

This paper presents a new method for the correction of the lens distortion for full-field measurement using dot centroid method. Displacement and strain can be obtained from full-field digital images, which include centroids represented by many dots on the specimen. The captured images are distorted by an optical system. Several ideas to remove such a distortion are developed, however the image is corrected by an interpolation for brightness intensity level. In short it is hard to achieve high accuracy for strain measurement by the interpolation, because high accuracy needs sub-pixel effect for computing a centroid.
In this paper, the dot centroid method is employed and the centroids are directly corrected by the proposed method, which directly compute the only positions of centroids. Due to the correction, 0.1% strain accuracy is accomplished and total computation time is reduced. Effectiveness of the idea is shown through numerical examples and the result of strain field measurement is presented and discussed.
Structural Optimization and LCA for a Computer-Aided Sustainable Design
Authors: Russo Davide , Matina Dario 
Published: September 2013

The present work sets the basis for the development of a systematic eco-sustainable computer aided design procedure. During years modules for the specific design of all phases of a product life-cycle have been developed: manufacturing, assembly, reliability, maintainability, resilience, disassembly, end-of-use, etc.
This work instead places itself in a broader context of “Design for ecology”. It means to overcome the limits of a classic design process such as “Design for X”, through an approach that makes the designer aware of the consequences that each design modification (to the geometry, the material or the manufacturing process) determines on the environmental impact of the product entire life-cycle.
This work proposes a method of integrated management of (1)virtual prototyping software (such as structural optimization, FEM and CAD), (2) function modelling methodology and (3) LCA tools. It is mainly based on the configuration of structural optimization strategies especially conceived to obtain lighter and more compact products, therefore, more eco-sustainable. The method, due to the nature of the instruments it employs, can be applied only to products that can be modelled in a CAD environment. The article, in particular, shows how to articulate the workflow between virtual prototyping and LCA tools.
A case study regarding a moped rim is used to explain the procedure while software implementation is still underway.
Evaluation of Whole-Body Navigation and Selection Techniques in Immersive 3D Environments
Authors: Klompmaker Florian , Dridger Alexander , Nebe Karsten 
Published: September 2013

Since 2010 when the Microsoft Kinect with its integrated depth-sensing camera appeared on the market, completely new kinds of interaction techniques have been integrated into console games. They don’t require any instrumentalization and no complicated calibration or time-consuming setup anymore. But even having these benefits, some drawbacks exist. Most games only enable the user to fulfill very simple gestures like waving, jumping or stooping, which is not the natural behavior of a user. In addition the depth-sensing technology lacks of haptic feedback. Of course we cannot solve the lack of haptic feedback, but we want to improve the whole-body interaction. Our goal is to develop 3D interaction techniques that give a maximum of freedom to the user and enable her to perform precise and immersive interactions.
This work focuses on whole-body interaction in immersive virtual environments. We present 3D interaction techniques that provide the user with a maximum of freedom and enables her to operate precisely and immersive in virtual environments. Furthermore we present a user study, in which we analyzed how Navigation and Manipulation techniques can be performed by users’ body-interaction using a depth-sensing camera and a huge projection screen. Therefore three alternative approaches have been developed and tested: classical gamepad interaction, an indirect pointer-based interaction and a more direct whole-body interaction technique. We compared their effectiveness and preciseness. It turned out that users act faster, while using the gamepad, but generate significantly more errors at the same time. Using depth-sensing based whole-body interaction techniques it became apparent, that the interaction is much more immersive, natural and intuitive, even if slower. We will show the advantages of our approach and how it can be used in various domains, more effectively and efficiently for their users.
An Experimental Approach to Assess the Disparities in the Usage Trends of Domestic Electric Lighting
Authors: Zaraket Toufic , Yannou Bernard , Leroy Yann , Minel Stephanie , Chapotot Emilie 
Published: September 2013

In a country like France, electricity consumption devoted to domestic lighting represents nearly a fifth of the total energy consumption of a building. The use of electric lighting is influenced by several factors such as the building’s structural characteristics, the activities of its occupants, the lighting equipments, and the level of natural light. Designers do take into account, in their energy models, the influence of occupants on the building’s overall energy consumption. However, these models still have some drawbacks regarding the comprehension of real “occupants’ energy behaviors” which play an important role in the discrepancies between predicted and real energy consumptions. The behavioral factors behind occupants’ usage trends of energy are still not thoroughly explored. Therefore, it is assumed that a better comprehension of these behaviors and consumption mechanisms could lead to the identification of technical solutions and energy saving potentials, thus resulting in a more robust building design.
The present paper aims to provide an insight into domestic lighting usages. The main objective is to explore the key factors (socio-demographic, economic, technical and behavioral) responsible for the disparities in lighting consumption between one household and another. For this purpose, an experiment is performed concurrently to the proposal of a lighting usage model. A micro level investigation protocol is elaborated and used to conduct in-depth studies on the usage patterns of electric lighting. The survey is conducted on a sample of 8 French households. The methodology for constructing the experimental protocol, its deployment, as well as the results obtained and their analysis are presented in this paper. The need for further qualitative and quantitative studies to better understand the usage trends of electric lighting is discussed.
Dynamic Performance of Neck Protection Devices: Performance Analysis Based on a Simplified Multibody Model of the Human Neck
Authors: Gobbi Massimiliano , Mastinu Gianpiero , Previati Giorgio , Tarallo Ermes 
Published: September 2013

This work is focused on the evaluation of the dynamic performance of different neck protection devices.
In order to evaluate the mechanical response of the safety devices, a multibody model of the human neck has been developed in Matlab™ SimMechanics™.
The mechanical behavior of the neck is described in the paper and different injury indices are presented and compared. The information about anatomy and physiology of the cervical spine of the neck has been collected from the literature, with particular focus on the mechanism of damage of vertebrae, disks and soft tissues.
The multibody model has been validated against experimental data available in the literature concerning impulsive loads representative of crash phenomena.
By means of the presented model, some relevant injury indices are computed for an accident involving a motorcyclist.
Since the focus has been set on mild injuries of the neck, the simulated crash should cause a high probability of injuries of the neck together with a low probability of damages of the head while wearing a standard helmet.
The performance of neck safety devices that link the helmet with the thoracic-shield are evaluated and compared. For sake of clearness, three types of neck safety devices are considered referencing to US patents: an airbag jacket, a 3D cushion wrapping the motorcyclist’s neck, and a “spring and dampers” system.
The airbag jacket has been modeled as a high stiffness and low deformation system by considering the airbag in its fully deployed configuration and by neglecting its dynamic performance during inflation phase. The other safety devices have been modeled as lumped parameters spring-damper systems.
A sensitivity analysis on the injury indexes has been performed by changing the stiffness and the damping parameters of these safety systems. The injury indexes collected by simulating the different neck safety systems have been compared.
A Quadricycle for Urban Mobility
Authors: Galmarini G. , Gobbi M. , Mastinu G. 
Published: September 2013

The need to decrease pollution in urban zones has pushed toward severe regulations in term of low-emission limits. The effect of this “environmental awareness” is an increased interest in electric vehicles (EV).
The construction of a EV is presented in the paper. This vehicle has been designed specifically to be powered by electric motors, the suspension system and the general layout have been developed accordingly.
According to the European technical regulations, the vehicle has been designed for a city use. The main features of GreenFun, (this is the name of the prototype), are an extensive use of composite and lightweight materials, a special suspension system layout, a 4WD powertrain realized by means of 4 electric motor hubs and the use, for the first time in a production vehicle, of 4 measuring wheels that are able to measure the forces acting between the pneumatic tires and the road. These information are used as input for the vehicle control systems in order to enhance performance and safety.
In the paper, the most relevant vehicle subsystems are described in detail (chassis, wheel, suspensions, powertrain, energy management, control system, …).
Design, Construction and Employment of a Sustainable “Urban Concept” Race Vehicle
Authors: Galmarini G. , Gobbi M. , Mastinu G. 
Published: September 2013

The construction of a plug-in electrical race vehicle is presented in the paper.
The vehicle is a prototype developed to be used for the Shell Eco-Marathon (SEM) competition. The main aim of SEM is to minimize fuel consumption. According to the technical regulations and the overall dimensions, the layout of the vehicle has been estimated in order to reduce the mass and the aerodynamic resistance of the vehicle. A high performance aerodynamic shape has been developed starting from the “Morelli’s shape” which has been further optimized to reduce the aerodynamic drag. A CFD analysis has been completed to refine the vehicle shape and to reach the final body geometry. To reduce the frontal area the wheels have been connected to the main body by using CFRP wing beams and both suspension system and powertrain, have been integrated into the wheels. A highly efficient powertrain has been developed and an electronic differential has been implemented. All the subsystems have been optimized both to reduce the motion resistance of the vehicle and to maximize the efficiency.
A numerical model of the vehicle has been developed in order to aid the design and to simulate the race strategy on different competition tracks. The model has been validated by considering data acquired during the race.
Mapping for Design Decision Support in Industry
Authors: Eng Nathan , Aurisicchio Marco , Bracewell Rob , Armstrong Gareth 
Published: September 2013

There has been a significant loss of spatial thinking support in the move from paper to computer-based work. Map-based software methods reported here fill this gap while resolving general challenges in deploying software tools into active industrial practice.
The Decision Rationale editor (DRed) has been in use over nine years and 700 engineers have been trained within the partner company. Semi-structured interviews were performed with 13 engineers from diverse departments and with a range of experience levels. Collected examples were analysed for successful methods (what), common contexts of use (where) and advantages over existing tools (why).
Map use seems to focus on problems where multiple poorly defined options need sorting in order to progress work. The diversity of use cases demonstrates a need for increased investment in flexible visual tools to aid human thinking. Future work will expand on the set of collected examples, including attempts to generalize lessons to other software. More detailed experiments are also needed to better understand specific cognitive benefits in the work environment.