bluuebunny/crossref_metadata_2025_split huggingface dataset:
Turnability of a Small UGV With Individual Wheel Skid-Steering on Soft Terrain
Authors: Zhang Siyuan , Vantsevich Vladimir V. 
Published: November 2018

Conventional turning mechanisms of wheeled skid-steer vehicles provide different velocities of the wheels at the left and right side while the wheels of each side are rigidly coupled and, thus, rotate with the same angular velocity. This turning principle has been employed for decades and provided high turnability of small unmanned ground vehicles (UGV) in both indoor and outdoor conditions with a high grip between pneumatic tires and surface of motion. However, as an analysis revealed, small UGVs habitually demonstrate non-sufficient turnability on deformable, extremely moisturized and heterogeneous terrains.
This paper proposes and develops new skid-steering inputs that are associated with de-coupled wheels, which are individually driven by either mechanical drivelines or electric motors. The skid-steering inputs are introduced as four kinematic discrepancy factors (KDF), which individually and, the same time in coordination with each other characterize kinematic and force variances of the UGV four drive wheels. In the paper, the KDF are explicitly determined as skid-steer variables through tire characteristics and parameters of individual mechanical and electric drivelines. The KDF are suitable for a lower vehicle sub-system control to individually manage the wheel torques.
The effectiveness of the skid-steering inputs is illustrated by analyzing vehicle understeer and oversteer maneuvers that are caused by various combinations of terrain conditions. A smooth and continuous transition from one to another KDF combination converts vehicle maneuvers and improves UGV turnability.
Development of Active Magnetic Bearing System Using Adaptive Feedforward Cancellation for Compensation and Analysis of External Forces in Rotating Machinery
Authors: Yabui Shota , Inoue Tsuyoshi 
Published: November 2018

In this research, a rotor system using active magnetic bearing has been proposed to analyze for external forces in rotating machineries. Dynamics of the rotating machineries are influenced from the various external forces such as unbalanced forces, oil film forces at a journal bearing, and seal contact forces. The characteristics of the external forces are dependent on rotating speed and rotating orbit of the rotating shaft. In development the rotating machineries, the analysis of the characteristics of external forces is required under various rotating condition. The proposed system can compensate and analyze for the external forces by using the adaptive feed-forward cancellation (AFC).
By using AFC, the proposed system can realize the desired rotating conditions under acting the external forces and analyze the characteristics external forces. The effectiveness of the proposed system has been confirmed experimentally.
A Flexible Chain Proposal for Winch Based Point Absorbers
Authors: Andersson Kjell , Hagnestål Anders , Sellgren Ulf 
Published: November 2018

Ocean wave power is a promising renewable energy source for future energy production. It has however been difficult to find a cost-effective solution to convert the wave energy into electricity. The harsh marine environment and the fact that wave power is delivered with high forces at low speeds makes design of durable mechanical structures and efficient energy conversion challenging. The dimensioning forces strongly depend on the wave power concept, the Wave Energy Converter (WEC) implementation and the actual Power Take-Off (PTO) system.
A WEC using a winch as a Power Take-Off system, i.e. a Winch Based Point Absorber (WBPA), could potentially accomplish a low Levelized Cost Of Energy (LCOE) if a key component — a low-cost, durable and efficient winch that can deal with high loads — can be developed.
A key problem for achieving a durable winch is to find a force transmitting solution that can deal with these high loads and handle up to 80 million cycles. In this article we propose a design solution for a force transmitting chain in a WBPA system where elastomeric bearings are used as a means to achieve the relative motion between the links in the chain. With this solution no sliding is present and the angular motion is achieved as a deformation in the elastomeric bearing when the chain is winded on a drum.
The link was designed primarily to minimize the number of joints in the chain: Thereby the maximum allowed relative angle between the links when rolled up over the drum should be as large as possible within practical limits. The angle is to be handled by the elastomeric bearing. A detailed strength analysis of the link has been performed as well as topology optimization to increase the strength to weight ratio.
A test rig for a first proof of concept testing has been developed and the first preliminary test results indicate that this concept with using elastomeric bearings can be a potential solution for a durable chain and should be analyzed further for fatigue conditions and under water operations.
A Hybrid Computational and Analytical Model of Inline Drip Emitters
Authors: Narain Jaya , Winter Amos G. 
Published: November 2018

This paper details a hybrid computational and analytical model to predict the performance of inline pressure-compensating (PC) drip irrigation emitters. The term inline refers to flow control devices mounted within the irrigation tubing. Pressure-compensating emitters deliver a relatively constant flow rate over a range applied pressure to accurately meter water to crops. Flow rate is controlled within the emitter by directing the water through a tortuous path (which imposes a fixed resistance), and then through a variable resistor composed of a flexible membrane that deflects under changes in pressure, restricting the flow path. An experimentally validated computational fluid dynamics (CFD) model was used to predict flow behavior through tortuous paths, and a pressure resistance parameter was derived to represent the pressure drop with a single variable. The bending and shearing mechanics of the membrane were modeled analytically and refined for accuracy by deriving a correction factor using finite element analysis. A least-squares matrix formulation that calculates the force applied by a line load of any shape, along which there is a prescribed deflection applied on a rectangular membrane, was derived and was found to be accurate to within one percent. The applicability of the assumption of locally fully developed flow through the pressure compensating chamber in a drip emitter was analyzed.
The combined hybrid computational-analytical model reduces the computational time of modeling drip emitter performance from days to less than 30 minutes, dramatically lowering the time required to iterate and select optimal designs. The model was validated using three commercially available drip emitters, rated at 1.1, 2, and 3.8 L/hr. For each, the model predicted the flow rate with an error of twenty percent or less, as compared to the emitter performance published by the manufacturer.
Instrumented Steering Wheel: Accurate Experimental Characterisation of the Forces Exerted by the Driver Hands for Future Advanced Driver Assistance Systems
Authors: Comolli Francesco , Ballo Federico M. , Gobbi Massimiliano , Mastinu Gianpiero 
Published: November 2018

The interaction between driver and vehicle is analyzed in the paper. The driver acts on the steering wheel to modify the trajectory and to control the vehicle during panic situations. The knowledge of the forces exerted by the driver at the steering wheel is useful for a better understanding of the driver steering action. The final aim is to inspire the development of haptic steering wheels for better tuning of Advanced Driver Assistance Systems (ADAS).
An instrumented steering wheel has been used, which includes two six axis load cells to measure the forces and the moments exerted by the driver hands and six sensors used to measure the grip strength. Two maneuvers have been considered, a moderate speed turn and a kick plate test which simulates a panic situation with an impulsive lateral disturbance. For both of the two considered situations, some common driving behaviors have been highlighted and analyzed.
The preliminary results encourage the development of haptic instrumented steering wheels, able to improve ADAS. Actually it seems possible to infer the driver steering purpose before the steering wheel is actually rotated.
A Study on the Structural Suitability of Tensegrity Structures to Serve As Morphing Aircraft Wings
Authors: Myszka David H. , Joo James J. 
Published: November 2018

This paper presents an investigation into the structural characterization of tensegrity systems for potential use as aircraft structures, especially for morphing aircraft. Morphing aircraft provide multi-role and multi-mission capabilities by adapting their performance to different in-flight requirements. Flexible elements must be included within the structure to permit morphing capabilities compared to conventional single mission aircraft, which are designed for high rigidity and not ideal for shape morphing applications.
Tensegrity systems are structures that consist of a series of connected cables, in tension, and struts, in compression, that exist in a self-equilibrium state. Since the struts and cables are loaded axially, external loads are efficiently distributed throughout the tensegrity components resulting in a strong and stiff structure. Adjusting the pretension of the tensegrity will tailor the structural characteristics as needed without a basic configuration change. By changing the length of the cables or struts, tensegrity systems are capable of movement while maintaining their inherent strength and rigidity. This makes tensegrity systems an attractive candidate for morphing aircraft structures.
This paper quantifies the strength and rigidity of a single module of various tensegrity systems along with traditional structures to assess their ability to serve as aircraft wings. Those properties are evaluated after boundary conditions are carefully selected to avoid adding unnecessary stiffness. Lastly, a concept for a tensegrity morphing aircraft wing is presented.
Managing Conflicting Water Resource Goals and Uncertainties in a Dam-Network by Exploring the Solution Space
Authors: Guo Lin , Zamanisabzi Hamed , Neeson Thomas M. , Allen Janet K. , Mistree Farrokh 
Published: November 2018

In a multi-reservoir system, ensuring adequate water availability across reservoirs while managing conflicting goals under uncertainties are critical to making the social-ecological system sustainable. The priorities of multiple user-groups and availability of the water resource may vary with time, weather and other factors. Uncertainties such as variation in precipitation bring more complexity, which intensifies the discrepancies between water supply and water demand for each user-group. To reduce such discrepancies, we should satisfice conflicting goals, considering typical uncertainties.
We observed that models are incomplete and inaccurate, which challenge the use of the single optimal solution to be robust to uncertainties. So, we explore satisficing solutions that are relatively insensitive to uncertainties, by incorporating different design preferences, identifying sensitive segments and improving the design accordingly. This work is an example of exploring the solution space to enhance sustainability in multidisciplinary systems, when goals conflict, preferences are evolving, and uncertainties add complexity.
Influence of the Subtended Angle on the Behavior of Folded Tape Springs
Authors: de Jong Marinus G. , van de Sande Werner W. P. J. , Herder Just L. 
Published: November 2018

Tape springs are thin-walled structures with zero longitudinal and constant transverse curvature. Folding them twice and connecting both ends creates a tape loop which acts as a linear guide. When using a tape spring with a non-constant cross-section, a force generator can be created. At this time there is insufficient understanding of the influence of the tape spring’s cross-section on its behavior. This study investigates the influence of the subtended angle on the tape spring’s behavior, especially the energy distribution and the fold radius.
A tape spring is once folded in a finite element model. By performing a curvature analysis of this folded geometry, the different regions within a tape spring are identified. This information is used to identify the amount of strain energy of each region. Finally, the fold radius and fold angle are determined by analyzing the geometry of the bent region.
The analysis showed that the energy within the transition regions cannot be neglected. The energy within these regions as ratio of the total energy and the length of the transition regions both increase with the subtended angle. It is also shown that the fold radius is not constant when the subtended angle is small.
Therefore, when designing a force generator using tape loops, the energy within the transition regions should be taken into account. The subtended angle should not be small to ensure a constant radius.
A Method to Analyse Generic Human Motion With Low-Cost Mocap Technologies
Authors: Regazzoni Daniele , Vitali Andrea , Rizzi Caterina , Colombo Giorgio 
Published: November 2018

A number of pathologies impact on the way a patient can either move or control the movements of the body. Traumas, articulation arthritis or generic orthopedic disease affect the way a person can walk or perform everyday movements; brain or spine issues can lead to a complete or partial impairment, affecting both muscular response and sensitivity. Each of these disorder shares the need of assessing patient’s condition while doing specific tests and exercises or accomplishing everyday life tasks. Moreover, also high-level sport activity may be worth using digital tools to acquire physical performances to be improved. The assessment can be done for several purpose, such as creating a custom physical rehabilitation plan, monitoring improvements or worsening over time, correcting wrong postures or bad habits and, in the sportive domain to optimize effectiveness of gestures or related energy consumption.
The paper shows the use of low-cost motion capture techniques to acquire human motion, the transfer of motion data to a digital human model and the extraction of desired information according to each specific medical or sportive purpose. We adopted the well-known and widespread Mocap technology implemented by Microsoft Kinect devices and we used iPisoft tools to perform acquisition and the preliminary data elaboration on the virtual skeleton of the patient.
The focus of the paper is on the working method that can be generalized to be adopted in any medical, rehabilitative or sportive condition in which the analysis of the motion is crucial. The acquisition scene can be optimized in terms of size and shape of the working volume and in the number and positioning of sensors. However, the most important and decisive phase consist in the knowledge acquisition and management. For each application and even for each single exercise or tasks a set of evaluation rules and thresholds must be extracted from literature or, more often, directly form experienced personnel. This operation is generally time consuming and require further iterations to be refined, but it is the core to generate an effective metric and to correctly assess patients and athletes performances. Once rules are defined, proper algorithms are defined and implemented to automatically extract only the relevant data in specific time frames to calculate performance indexes. At last, a report is generated according to final user requests and skills.
Environmental Evaluation of Papercrete Based on Life Cycle Assessment
Authors: Wang Xiang , Tate Derrick , Chin Chee 
Published: November 2018

Papercrete, which uses waste paper as an alternative ingredient in concrete, is regarded as one type of mix design for green concrete that provide a new opportunity for waste paper disposal. However, the specific environmental influence of introducing waste paper has not been not clarified. Therefore, to evaluate the environmental contribution and feasibility of papercrete, based on the papercrete unit, the comparison of concrete production coupled with waste paper disposal is conducted according to a Life Cycle Assessment (LCA) analysis.
The system of papercrete production discussed here covers raw material extraction to finished product. Three different treatments for waste paper combined with concrete production are considered in this study. With respect to most environmental indicators, the results indicate that papercrete by introducing waste paper achieves some environmental benefits. The major reasons that environmental indicators of papercrete improve are due to the reduction of natural resource utilization and emissions to air. In detail the environmental impacts of papercrete production acquire a remarkable improvement compared with impact of normal concrete production and the adoption of incineration disposal of waste paper. Nevertheless, the environmental benefits of papercrete production are not significant increased compared with the associated system when waste paper is collected for the manufacture of recycled paper, where most environmental indicators of papercrete production are only slightly increased.
Identifying Failure Modes and Effects Through Design for Assembly Analysis
Authors: Hein Phyo Htet , Voris Nate , Dai Jiaying , Morkos Beshoy W. 
Published: November 2018

Design for Assembly (DFA) time estimation method developed by G. Boothroyd and P. Dewhurst allows for estimating the assembly time of artifacts based on analysis of component features using handling and insertion tables by an assembler, who is assumed to assemble the artifact one-part-at-a-time. Using the tables, each component is assigned an assembly time which is based on the time required for the assembler to manipulate (handling time) and the time required for it to interface with the rest of the components (insertion time). Using this assembly time and the ideal assembly time (i.e. the absolute time it takes to assemble the artifact, assuming each component takes the ideal time of three seconds to handle and insert), this method allows to calculate the efficiency of a design’s assembly process. Another tool occasionally used in Design for Manufacturing (DFM) is Failure Modes and Effects Analysis (FMEA). FMEA is used to evaluate and document failure modes and their impact on system performance. Each failure mode is ranked based on its severity, occurrence, and detectability scores, and corrective actions that can be taken to control risk items. FMEA scores of components can address the manufacturing operations and how much effort should be put into each specific component. In this paper, the authors attempt to answer the following two research questions (RQs) to determine the relationships between FMEA scores and the DFA assembly time to investigate if part failure’s severity, occurrence, and detectability can be estimated if handling time and insertion time are known.
RQ (1): Can DFA metrics (handling time and insertion time) be utilized to estimate Failure Mode and Effects scores (severity, occurrence, and detectability)?
RQ (2): How does each response metric relate to predictor metrics (positive, negative, or no relationship)?
This is accomplished by performing Boothroyd and Dewhurst’s DFA time estimation and FMEA on select set of simple products. Since DFA metrics are based on combination of designer’s subjectivity and part’s geometric specifications and FMEA scores are based only on designer’s subjectivity, this paper attempts to estimate part failure severity, occurrence, and detectability less subjectively by using the handling time and insertion time. This will also allow for earlier and faster acquisition of potential part failure information for use in design and manufacturing processes.
Simulating Occupant Response to Low Speed, Automotive Rear-End Collisions
Authors: Kames Elisabeth , Thiess David , Kepinski Paul , Zaremba Ryan , Morkos Beshoy 
Published: November 2018

This paper outlines the modeling and analysis of an occupant’s response to a low speed, in-line, rear end collision. The response of the occupant was modeled using two methods; MATLAB was used to model the equations of motion of the occupant’s head, neck and spine and ANSYS Workbench was used to perform a structural analysis of the occupant’s spine and head.
The occupant was assumed to be an average sized male, with a spine length of about 30”. The occupant was also assumed to be unaware of the impact, therefore not bracing themselves against the impact. Both of the vehicles were assumed to be 2000 kg. The leading (target) vehicle is stopped producing a velocity of 0 km/h, and the trailing (bullet) vehicle is going 16.1 km/h (10mph) producing an acceleration on impact of 22.35 m/s2. Both the MATLAB model and ANSYS model assumed that the occupant was not wearing a seat belt.
The ANSYS simulation produced an acceleration of the head of 9.40 g’s, while the MATLAB model produced 5.10 g’s of acceleration at the head. These values were compared to literature of experimental crash tests.
The results obtained from the two models were compared to one another as well as literature values from multiple sources to validate the results obtained. This report will outline the formulation of the two models, the results obtained from the two models, a comparison between the models, and a comparison to literature results for experimental test data.
Parents’ perception of children’s mental health: seeing the signs but not the problems
Authors: Huang Li , Hiscock Harriet , Dalziel Kim M 
Published: November 2018

BackgroundIt is a public heath priority to understand why many children with mental health problems fail to access mental health services. This study aims to quantify under-recognition of children’s mental health problems by parents across income quintiles.MethodsWe estimated under-recognition with parent-reported mental health problems and the Strengths and Difficulties Questionnaire (SDQ) using a nationally representative Australian data set for children aged 4–15 years with 24 269 person-wave observations.ResultsUnder-recognition was the highest in the lowest income quintile, with 11.5% of children from the lowest income quintile families who scored in the clinical range on the SDQ perceived by parents as having no mental health problems. For the highest income quintile this was 2.4%. In terms of gender and age, under-recognition was greater for boys and younger children.ConclusionsParent’s mental health literacy, especially for low-income families, warrants prioritised attention from researchers, clinicians and policymakers.