Criteria

Display:

Results

Viewing 1 to 30 of 4754
2016-11-08
Technical Paper
2016-32-0049
Kuniyoshi Eto, Masaru Nozawa, Masato Nara, Buhei Kobayashi, Daiki Shibasaki, Ken Shirai
A new air-cooled SI two-stroke gasoline engine has been developed for an arborist-chainsaw. This engine has a displacement of 25 mm3 and generates about 1.1 kW and complies with the latest CARB and EPA exhaust regulations by optimizing scavenging flows and the use of a catalytic converter. Characteristics of lightweight, compact and high power-to-weight ratio are required for handheld chainsaws, especially for arborist chainsaws. As a matter of course, these characteristics are needed for engine itself in order to satisfy such market requirements for hand-held power equipment. To realize lightweight and compact design, the placement of catalytic converter is optimized for the engine and a two-piece crankshaft is adopted.
2016-11-08
Journal Article
2016-32-0034
Stephan Jandl, Hans-Juergen Schacht, Stephan Schmidt, Ute Dawin, Armin Kölmel, Stefan Leiber
The worldwide increasing energy consumption, the decreasing energy resources and the continuous restriction of emission legislation cause a rethinking in the development of internal combustion engines and fuels. Alternative renewable fuels, so called bio-fuels, have the potential to counteract these problems. This study concentrates on the usage of alcohol fuels like Ethanol, Methanol and Butanol in non-automotive high power engines, handheld power tools and garden equipment with the focus on mixture formation and cold start capability. Although bio-fuels have been investigated intensely for the use in automotive applications, the different propulsion systems and operation scenarios of non-automotive applications raise the need for specific research. Therefore, a zero dimensional vaporization model was set up to illustrate the connections between physical properties and mixture formation.
2016-10-17
Technical Paper
2016-01-2159
Zheming Li, Yann Gallo, Ted Lind, Oivind Andersson, Marcus Alden, Mattias Richter
Soot emission from internal combustion engines is strictly regulated and upcoming requirements present a challenge. Laser extinction measurement (LEM) and natural luminosity of sooty flames have been used to analyze soot formation and oxidation processes. LEM measures soot along the laser beam path and it can probe soot regardless of temperature. Natural luminosity measurement is a global measurement and highly relies on soot temperature. In this work, a comparison of simultaneously recorded LEM and natural luminosity data has been performed in a heavy-duty optical engine. A 685 nm laser beam is used for LEM to minimize the absorption by fuel or PAH. The laser was modulated at 63 kHz, which facilitated subtraction of the background natural luminosity signal from the raw LEM data. Temporal offset is found between the LEM and natural luminosity data. The LEM detects ‘soot’ earlier than natural luminosity measurement.
2016-09-27
Technical Paper
2016-01-8132
Sanket Pawar
Abstract Reliability engineering methods are used to assess risk and eliminate hazards by estimation, elimination, and management of risks of failures. The ISO 26262 functional safety standard gives detailed guidance on reliability engineering methods like Failure Mode and Effect Analysis (FMEA) [7], Fault Tree Analysis (FTA) [8] [2], and etc. While, there are many methods available for reliability engineering; no single method is foolproof for securing safety by eliminating hazards completely. Out of these methods, FMEA is widely being used as an integral part of the product development life cycle [10]. In this method, failure modes of individual components are analyzed considering one failure at a time. FMEA is an efficient method for analyzing failures in simple systems. For complex systems, FMEA becomes impractical. It is also difficult to consider variables in FMEA.
2016-09-27
Technical Paper
2016-01-2077
Fatih Burak Sahin, Hans-Juergen Borchers, Cagatay Ucar
Abstract CFRP has been widely used in aerospace industries because of its high strength-to-weight ratio. However, drilling CFRP laminates is difficult due to the highly abrasive nature of the carbon fibers and low thermal conductivity of CFRP. Therefore for the manufacturers it is a challenge to drill CFRP materials without causing any delamination within the high quality requirements while also considering the costs of the process. This paper will discuss the process of drilling CFRP-Al stack ups within tight tolerances using a seven axis drilling robot. All components required for drilling are integrated in the drill end-effector. The pressure foot is extended in order to clamp the work piece, and then holes are drilled. The drilling process has four steps: moving to the fast approach level, controlled drill feed, countersink depth reach and drill retract. The cutter diameter range chosen for this paper is Ø 4.0 mm and Ø 7.9 mm.
2016-09-27
Technical Paper
2016-01-2096
Simon Schnieders, Dirk Eickhorst
Abstract Drilling of high-strength titan material and composites in combination creates complex challenges in order to achieve required productivity and quality. Long spiral chips are characteristically for the titan drilling process, which leads to e.g. chip accumulation, high thermomechanical load, surface damages and excessive tool wear. The basic approach is the substitution of today’s peck drilling as current solution to this problem and the implementation of a vibration assisted drilling, so called micro-peck-drilling-process, to generate a kinematic chip breakage in a significant more efficient way. To meet perfectly the requirements regarding rates, quality and automation level, Broetje-Automation as system integrator has investigated and developed the implementation of different alternative high-performance systems and methods to approach the optimal oscillation movement of the tool.
2016-09-27
Technical Paper
2016-01-2106
Dan R.W. Vaughan, Otto J. Bakker, David Branson, Svetan Ratchev
Abstract Aircraft manufacturers desire to increase production to keep up with anticipated demand. To achieve this, the aerospace industry requires a significant increase in the manufacturing and assembly performance to reach required output levels. This work therefore introduces the Variation Aware Assembly (VAA) concept and identifies its suitability for implementation into aircraft wing assembly processes. The VAA system concept focuses on achieving assemblies towards the nominal dimensions, as opposed to traditional tooling methods that aim to achieve assemblies anywhere within the tolerance band. It enables control of the variation found in Key Characteristics (KC) that will allow for an increase in the assembly quality and product performance. The concept consists of utilizing metrology data from sources both before and during the assembly process, to precisely position parts using motion controllers.
2016-09-27
Technical Paper
2016-01-2108
Marc Fette, Kim Schwake, Jens Wulfsberg, Frank Neuhaus, Manila Brandt
Abstract The rising demand for civil aircraft leads to the development of flexible and adaptive production systems in aviation industry. Due to economic efficiency, operational accuracy and high performance these manufacturing and assembly systems must be technologically robust and standardized. The current aircraft assembly and its jigs are characterized by a high complexity with poor changeability and low adaptability. In this context, the use of industrial robots and standardized jigs promise highly flexible and accurate complex assembly operations. This paper deals with the flexible and adaptable aircraft assembly based on industrial robots with special end-effectors for shaping operations. By the development and use of lightweight gripper system made of carbon fiber reinforced plastics the required scaling, robustness and stiffness of the whole assembly system can be realized.
2016-09-27
Technical Paper
2016-01-2110
Ilker Erdem, Peter Helgosson, Ashwin Gomes, Magnus Engstrom
Abstract The ability to adapt to rapidly evolving market demands continues to be the one of the key challenges in the automation of assembly processes in the aerospace industry. To meet this challenge, industry and academia have made efforts to automate flexible fixturing. LOCOMACHS (Low Cost Manufacturing and Assembly of Composite and Hybrid Structures) - a European Union funded project with 31 partners - aims to address various aspects of aero-structure assembly with a special attention directed to the development of a new build philosophy along with relevant enabling technologies. This paper aims to present the results on the developed wing box build philosophy and the integration of automated flexible tooling solutions into the assembly process. The developed solution constitutes the use of synchronized hexapods for the assembly of front spar to upper cover whereas another hexapod was developed to install a rib by using of a force feedback sensor.
2016-09-27
Technical Paper
2016-01-2109
Michael Morgan, Caroline McClory, Colm Higgins, Yan Jin, Adrian Murphy
Aerospace structures are typically joined to form larger assemblies using screw lock or swage lock fasteners or rivets. Countersunk fasteners are used widely in the aerospace industry on flying surfaces to reduce excrescence drag and increase aircraft performance. These fasteners are typically installed to a nominal countersink value which leaves them flush to the surface before being locked into position. The Northern Ireland Technology Centre (NITC) at Queen’s University Belfast has developed and demonstrated two processes which enable high tolerance flush fastening of countersunk fasteners: The ‘Flush Install’ process produces countersunk holes based on the specific geometry of each individual fastener; The ‘Fettle Flush’ process accurately machines fasteners to match the surrounding surface. Flushness values well within the allowable tolerances have been demonstrated for both Flush Install and Fettle Flush processes.
2016-09-27
Technical Paper
2016-01-2107
Rainer Mueller, Matthias Vette, Matthias Scholer, Jan Ball
Abstract The global competition challenges aircraft manufactures in high wage countries. The assembly of large components is very difficult and distinguished by fixed position assembly. Many complex assembly processes such as aircraft assembly are manually done by highly skilled workers. The aircraft manufactures deal with a varying number of items, increasing number of product variants and strict product requirements. During the assembly process hundreds of clips, ties and stringers as well as thousands of rivets must be assembled. To remain competitive in global competition, companies in high wage countries like Germany must insure a continuously high productivity and quality level. To achieve a reduction of cycle times with a simultaneous increase in quality, supportive assistance systems for visual support, documentation and organization within the assembly are required. One example for visual assistance systems are laser projection systems.
2016-09-27
Technical Paper
2016-01-2127
Sylvain Guerin, Sylvain da Costa
Abstract The recent contribution rise in 3D printing is rapidly changing the whole industry. In aeronautics, it has 2 major domains of growth: Aircraft parts Tooling and portable tools Aircraft parts in metallic 3D printing have been highly publicized in the media, although they represent only a tiny share of the aircraft cell in the short term. On the other hand, metallic (and non-metallic) 3D printing in tooling and tools can bring immediate advantages compared to traditional methods. The advantages: Design made directly for the final function Optimized for strength vs weight Weight reduction Reduction in number of parts Short cycle time from design to use Low cost for customization The drawbacks Limited in size We have already applied this new manufacturing technique to obtain real breakthroughs in portable tools.
2016-09-27
Journal Article
2016-01-8011
Kevin Grove, Jon Atwood, Myra Blanco, Andrew Krum, Richard Hanowski
Abstract This study evaluated the performance of heavy vehicle crash avoidance systems (CASs) by collecting naturalistic driving data from 150 truck tractors equipped with Meritor WABCO OnGuardTM or Bendix® Wingman® AdvancedTM products. These CASs provide drivers with audio-visual alerts of potential conflicts, and can apply automatic braking to mitigate or prevent a potential collision. Each truck tractor participated for up to one year between 2013 and 2015. Videos of the forward roadway and drivers’ faces were collected along with vehicle network data while drivers performed their normal duties on revenue-producing routes. The study evaluated the performance of CAS activations by classifying them into three categories based on whether a valid object was being tracked and whether drivers needed to react immediately.
2016-09-27
Technical Paper
2016-01-8014
David A. Schaller, Michael D. Roeth
Abstract This report provides an overview of recent technical solution adoption rates by fleets from detailed fleet surveys. Manufacturers’ contributions in terms of technology development, cost reduction, durability and refinement will also be discussed. OEM vehicle integration and product line offerings (standard, optional, and post-production upfits) are shared. All of this background will set the stage for a review of the proposed Greenhouse Gas Phase 2 regulations, the technologies expected to be utilized to meet the targets, and the hurdles the industry must successfully clear for profitable fleet use in commercial vehicle freight transportation. Fuel efficiency has always been important to fleets and as fuel costs have risen, a plethora of fuel efficient technologies have emerged. The industry also cares about sustainability and emissions reductions and now Greenhouse Gas regulations exist to further encourage development, integration and adoption of such technologies.
2016-09-27
Journal Article
2016-01-2082
Ralf Schomaker, Björn Knickrehm, Jürgen Langediers
Abstract In the frame of incremental product improvement, AIRBUS has developed and implemented a new innovative rapid decompression / pressure relieve concept for the cargo compartment area. The core change lays with detaching the complete cargo lining panels from the substructure in case of a rapid decompression in the cargo area instead of using dedicated blow in panels. In that way, pressure equilibrium can be achieved by air flow through the opened areas around the cargo lining panels rather than through specific blow out / blow in venting areas. The key for this is a self-detaching fastener AIRBUS has developed in an outstanding cooperation with ARCONIC Fastening Systems & Rings (former Alcoa Fastening Systems & Rings) in Kelkheim, Germany. These fasteners are installed to keep the cargo lining panels in place and tight against smoke in case of fire which is one of the main purposes for their use.
2016-09-20
Journal Article
2016-01-2022
Ajay Rao, Vivek Karan, Pradeep Kumar
Abstract Turbulence is by far the number one concern of anxious passengers and a cause for airline injuries. Apart from causing discomfort to passengers, it also results in unplanned downtime of aircrafts. Currently the Air Traffic Control (ATC) and the meteorological weather charts aid the pilot in devising flight paths that avoid turbulent regions. Even with such tailored flight paths, pilots report constant encounters with turbulence. The probability of turbulence avoidance can be increased by the use of predictive models on historical and transactional data. This paper proposes the use of predictive analytics on meteorological data over the geographical area where the aircraft is intended to fly. The weather predictions are then relayed to the cloud server which can be accessed by the aircraft planned to fly in the same region. Predictive algorithms that use Time series forecasting models are discussed and their comparative performance is documented.
2016-09-20
Journal Article
2016-01-2024
Allan J. Volponi, Liang Tang
Abstract Engine module performance trending and engine system anomaly detection and identification are core capabilities for any engine Condition Based Maintenance system. The genesis of on-condition monitoring can be traced back nearly 4 decades, and a methodology known as Gas Path Analysis (GPA) has played a pivotal role in its evolution. GPA is a general method that assesses and quantifies changes in the underlying performance of the major modules of the engine (compressors and turbines) which directly affect performance changes of interest such as fuel consumption, power availability, compressor surge margins, and the like. This approach has the added benefit in that it enables anomaly detection and identification of many engine system accessory faults (e.g., variable stator vanes, handling and customer bleeds, sensor biases and drift).
2016-09-20
Technical Paper
2016-01-2046
Neno Novakovic
Abstract A Landing Gear Control and Actuation System (LGCAS) is one of the most complex aircraft systems. Due to the large landing gear masses and high performance requirements, aircraft hydraulic power with multiple hydraulic actuators and valves is used to provide system dynamic. LGCAS also requires a electrical source of energy for the electro-mechanical components, sensors and electronic control unit. For many years, correct fault isolation in a complex kinematic system, such as an aircraft landing gear actuation system, has been a great challenge with limited success. The fault isolation design challenge rests on the fact that landing gear control and actuation system has many so called “passive” components, whose basic function cannot be continuously monitored without additional sensors, transducers, and designated health monitoring equipment.
2016-06-15
Technical Paper
2016-01-1836
Sylvestre Lecuru, Pascal Bouvet, Jean-Louis Jouvray, Shanjin Wang
Abstract The recent use of electric motors for vehicle propulsion has stimulated the development of numerical methodologies to predict their noise and vibration behavior. These simulations generally use models based on an ideal electric motor. But sometimes acceleration and noise measurements on electric motors show unexpected harmonics that can generate acoustic issues. These harmonics are mainly due to the deviation of the manufactured parts from the nominal dimensions of the ideal machine. The rotor eccentricities are one of these deviations with an impact on acoustics of electric motors. Thus, the measurement of the rotor eccentricity becomes relevant to understand the phenomenon, quantify the deviation and then to use this data as an input in the numerical models. An innovative measurement method of rotor eccentricities using fiber optic displacement sensors is proposed.
2016-04-05
Technical Paper
2016-01-0865
R. Lockett, Mahesh Jeshani, Kassandra Makri, Richard Price
Abstract High-speed planar laser Mie scattering and Laser Induced Fluorescence (PLIF) were employed for the determination of Sauter Mean Diameter (SMD) distribution in non-evaporating diesel sprays. The effect of rail pressure, distillation profile, and consequent fuel viscosity on the drop size distribution developing during primary and secondary atomization was investigated. Samples of conventional crude-oil derived middle-distillate diesel and light distillate kerosene were delivered into an optically accessible mini-sac injector, using a customized high-pressure common rail diesel fuel injection system. Two optical channels were employed to capture images of elastic Mie and inelastic LIF scattering simultaneously on a high-speed video camera at 10 kHz. Results are presented for sprays obtained at maximum needle lift during the injection. These reveal that the emergent sprays exhibit axial asymmetry and vorticity.
2016-04-05
Technical Paper
2016-01-1195
Atsushi Baba, Kinnosuke Itabashi, Nozomu Teranishi, Yoshihiro Edamoto, Kensuke Osamura, Ichiro Maruta, Shuichi Adachi
Abstract This paper proposes a battery state estimation on a battery management system (BMS) for hybrid electric vehicles (HEVs) and electric vehicles (EVs). It is important to estimate a state of charge (SOC) and parameters of the battery such as a state of health (SOH), internal resistances and dynamics of electrochemical reactions. The BMS can provide information on the driving range of the EVs to the drivers by accurately estimating SOC and SOH. It can also calculate a state of power (SOP) to use the battery safely by accurately estimated SOC, internal resistances and others. For that purpose, this paper proposes the BMS adopted a simultaneous state of charge (SOC) and parameter estimation method using log-normalized unscented Kalman filter (LnUKF). The key idea is a lognormalization of the parameters to improve numerical stability and robustness of the algorithm. The proposed system is verified by a series of simulations using experimental data with EVs.
2016-04-05
Technical Paper
2016-01-1212
Yupu Chen, Miaohua Huang
Abstract Lithium-ion battery plays a key role in electric vehicles, which is critical to the system availability. One of the most important aspects in battery managements systems(BMS) in electric vehicles is the stage of health(SOH) estimation. The state of health (SOH) estimation is very critical to battery management system to ensure the safety and reliability of EV battery operation. The classical approach of current integration(coulomb counting) can't get the accurate values because of accumulative error. In order to provide timely maintenance and replacements of electric vehicles, several estimation approaches have been proposed to develop a reliable and accurate battery state of health estimation. A common drawback of previous algorithm is that the computation quantity is huge and not quite accurate, that is updated partially in this study.
2016-04-05
Technical Paper
2016-01-1112
Byeong Wook Jeon, Sang-Hwan Kim, Donghoon Jeong, Joseph Young-il Chang
Abstract In general, driving performance is developed to meet preference of average customers. But there is no single standardized guideline which can satisfy various driving tastes of all drivers whose gender, cultural background, and age are different. To resolve this issue, automotive companies have introduced drive mode buttons which drivers can manually select from Normal, Eco, and Sport driving modes. Although this multi-mode manual systems is more efficient than single-mode system, it is in a transient state where drivers need to go through troubles of frequently selecting their preferred drive mode in volatile driving situations It is also doubtful whether the three-categorized driving mode can meet complex needs of drivers.. In order to settle these matters, it is necessary to analyze individual driving style automatically and to provide customized driving performance service in real time.
2016-04-05
Technical Paper
2016-01-0072
Jihas Khan
Abstract Unified Diagnostic Service and On Board Diagnostics require a client side device with necessary software to implement certain specific algorithms. This paper proposes a highly optimized and generic model based architecture to implement client side algorithms used in Unified Diagnostic Service systems and with On Board Diagnostics which can be reused for any hardware target. The proposed method can implement particular algorithms which include flow control, timing control, database parsing, logging of messages, diagnostic database parsing, security unlock, intuitive HMI layer, DTC display with textual information, frame control, multi network - multi ECU support, software flashing, physical-functional message handling, and interfacing for multiple hardware host devices. Re-usability of this model based product ensures that it can be ported to the diagnostic tool used by a work shop engineer or by a diagnostics validation engineer working at OEM or Tier 1suppliers.
2016-04-05
Technical Paper
2016-01-0684
Shinji Matsuo, Eiji Ikeda, Yoshiaki Ito, Hiroyuki Nishiura
Abstract The engine in the new fourth generation Prius carries over the same basic structure as the 2ZR-FXE used in the third generation and incorporates various refinements to enhance fuel efficiency. Called the ESTEC 2ZR-FXE, the new engine incorporates various fuel efficient technologies to improve combustion characteristics, knocking, and heat management, while also reducing friction. As a result of this meticulous approach to enhancing fuel efficiency, the new engine is the first gasoline engine in the world to achieve a maximum thermal efficiency of 40%. This paper describes the fuel efficient technologies incorporated into this engine.
2016-04-05
Technical Paper
2016-01-0271
David A. Warren
Abstract The objective of the paper is to outline the steps taken to change the reliability and maintenance environment of a plant from completely reactive to proactive. The main systems addressed are maintenance function fulfillment with existing staffing; work order management, planning, and scheduling; preventive maintenance (PM) definition and frequency establishment; predictive maintenance (PdM) scheduling and method definition; and shutdown planning and execution. The work order management methods were evaluated and modified to provide planning and scheduling of work orders on a weekly basis. The computerized maintenance and management system (CMMS) was updated to automatically insert work orders into the backlog of work for completion. A failure modes and effects analysis (FMEA) was performed and the results of the FMEA led to implementation of the following PM and PdM activities: vibration analysis, thermal imaging, and temperature monitoring.
2016-04-05
Technical Paper
2016-01-0270
Zhigang Wei, Limin Luo, Michael Start, Litang Gao
Product validation and reliability demonstration require testing of limited samples and probabilistic analyses of the test data. The uncertainties introduced from the tests with limited sample sizes and the assumptions made about the underlying probabilistic distribution will significantly impact the results and the results interpretation. Therefore, understanding the nature of these uncertainties is critical to test method development, uncertainty reduction, data interpretation, and the effectiveness of the validation and reliability demonstration procedures. In this paper, these uncertainties are investigated with the focuses on the following two aspects: (1) fundamentals of the RxxCyy criterion used in both the life testing and the binomial testing methods, (2) issues and benefits of using the two-parameter Weibull probabilistic distribution function.
2016-04-05
Technical Paper
2016-01-0289
Balakrishna Chinta
Abstract Mahalanobis Distance (MD) is gaining momentum in many fields where classification, statistical pattern recognition, and forecasting are primary focus. It is a multivariate method and considers correlation relationships among parameters for computing generalized distance measure to separate groups or populations. MD is a useful statistic in multivariate analysis to test that an observed random sample is from a multivariate normal distribution. This capability alone enables engineers to determine if an observed sample is an outlier (defect) that falls outside the constructed (good) multivariate normal distribution. In Mahalanobis-Taguchi System (MTS), MD is suitably scaled and used as a measure of severity in abnormality assessment. It is obvious that computed MD depends on values of parameters observed on a random sample. All parameters may not equally impact MD. MD could be highly sensitive with respect to some parameters and less sensitive to some other parameters.
2016-04-05
Technical Paper
2016-01-0274
Sharon L. Honecker, David J. Groebel, Adamantios Mettas
Abstract In order to accurately predict product reliability, it is best to design a test in which many specimens are tested for a long duration. However, this scenario is not often practical due to economic and time constraints. This paper describes a reliability test in which a limited number of specimens are tested with little time remaining before the scheduled start of production. During the test, an unexpected failure mode that can be mitigated through a product redesign occurs. Because the scheduled start of production is near, there is not enough time to perform a test with redesigned specimens, so the current test proceeds as planned. We discuss several methods and the associated assumptions that must be made to account for the presence of the unexpected failure mode in the test data in order to make predictions of reliability of the redesigned product.
2016-04-05
Technical Paper
2016-01-0279
Chong Chen, Zhenfei Zhan, Jie Li, Yazhou Jiang, Helen Yu
Abstract To reduce the computational time of the iterations in robust design, meta-models are frequently utilized to approximate time-consuming computer aided engineering models. However, the bias of meta-model uncertainty largely affects the robustness of the prediction results, this uncertainty need to be addressed before design optimization. In this paper, an efficient uncertainty quantification method considering both model and parameter uncertainties is proposed. Firstly, the uncertainty of parameters are characterized by statistical distributions. The Bayesian inference is then performed to improve the predictive capabilities of the surrogate models, meanwhile, the model uncertainty can also be quantified in the form of variance. Monte Carlo sampling is finally utilized to quantify the compound uncertainties of model and parameter. Furthermore, the proposed uncertainty quantification method is used for robust design.
Viewing 1 to 30 of 4754