Criteria

Display:

Results

Viewing 151 to 180 of 4788
2014-09-16
Technical Paper
2014-01-2132
Prashant Vadgaonkar, Ullas Janardhan, Adishesha Sivaramasastry
Abstract Performance of Avionics systems is dictated by the timely availability and usage of critical health parameters. Various sensors are extensively used to acquire and communicate the desired parameters. In today's scenario, sensors are hardwired. The number of sensors is growing due to automation which increases the accuracy of intended Aircraft functions. Sensors are distributed all over the Aircraft and they are connected through wired network for signal processing and communication. LRUs (Line Replaceable Unit) which are integrating various sensors also use a wired approach for communication. The use of a wired network approach poses challenges in terms of cable routing, stray capacitances, noise, mechanical structure and added weight to the structure. The weight of cables contributes significantly to the overall weight of the aircraft. As the weight of Aircraft increases, the required fuel quantity also increases. The Key driver for Airline operational cost is fuel.
2014-05-10
Journal Article
2014-01-9121
Robert E Smith, Edward Lumsdaine
Since transient vehicle HVAC computational fluids (CFD) simulations take too long to solve in a production environment, the goal of this project is to automatically create a lumped-parameter flow network from a steady-state CFD that solves nearly instantaneously. The data mining algorithm k-means is implemented to automatically discover flow features and form the network (a reduced order model). The lumped-parameter network is implemented in the commercial thermal solver MuSES to then run as a fully transient simulation. Using this network a “localized heat transfer coefficient” is shown to be an improvement over existing techniques. Also, it was found that the use of the clustering created a new flow visualization technique. Finally, fixing clusters near equipment newly demonstrates a capability to track localized temperatures near specific objects (such as equipment in vehicles).
2014-05-09
Journal Article
2014-01-9025
John O. Manyala
The emergence of tougher environmental legislations and ever increasing demand for increased ride comfort, fuel efficiency, and low emissions have triggered exploration and advances towards more efficient vehicle gearbox technologies. The growing complexity and spatial distribution of such a mechatronic gearbox demands precise timing and coordination of the embedded electronics, integrated sensors and actuators as well as excellent overall reliability. The increased gearbox distributed systems have seen an increased dependence on sensors for feedback control, predominantly relying on hardware redundancy for faults diagnosis. However, the conventional hardware redundancy has disadvantages due to increased costs, weight, volume, power requirements and failure rates. This paper presents a virtual position sensor-based Fault Detection, Isolation and Accommodation (FDIA), which generates an analytical redundancy for comparison against the actual sensor output.
2014-05-09
Journal Article
2014-01-9022
John O. Manyala, Todd W. Fritz
Electro-hydraulic actuated systems are widely used in industrial applications due to high torque density, higher speeds and wide bandwidth operation. However, the complexities and the parametric uncertainties of the hydraulic actuated systems pose challenges in establishing analytical mathematical models. Unlike electro-mechanical and pneumatic systems, the nonlinear dynamics due to dead band, hysteresis, nonlinear pressure flow relations, leakages and friction affects the pressure sensitivity and flow gain by altering the system's transient response, which can introduce asymmetric oscillatory behavior and a lag in the system response. The parametric uncertainties make it imperative to have condition monitoring with in-built diagnostics capability. Timely faults detection and isolation can help mitigate catastrophic failures. This paper presents a signal-based fault diagnostic scheme for a gearbox hydraulic actuator leakage detection using the wavelet transform.
2014-04-28
Technical Paper
2014-28-0011
Santosh Bhoomaraddi
Abstract The influence of embedded optical fibre on the strength and stiffness of flexurally loaded composite laminate is studied in this paper. In a given structure, different loads create a complex state of stresses in the structure. In-situ structural health monitoring of composite structures could be achieved by using embedded optical fiber as sensors. Modern OFS (Optical Fibre Sensors) are suitable for the measurement of temperature, pressure, strain, angular rotation, speed, acceleration, curvature, flow, refractive index, and many other parameters. The strength and fracture behaviour of the structure could be significantly affected by improper alignment and placement of optical fibres in the laminate. The utilization of embedded optical fibres for damage detection is accurate and reliable if the interaction between the optical fibre and the delamination is known.
2014-04-01
Technical Paper
2014-01-0747
Youji Hiraoka, Katsunari Yamamoto, Tamotsu Murakami, Yoshiyuki Furukawa, Hiroyuki Sawada
Abstract The authors propose computerized support for Fault Tree Analysis (FTA) based on new knowledge management in product design. FTA is a method of analyzing and visualizing the causes of a fault event by Fault Tree diagram (FT diagram) that has a tree structure with logical step. Many methods of support for FTA are studied, but they are not effective for our FTA. We have developed the system of Computer-Aided FTA (FTAid) for design engineers by the collaborative research group (JATCO Ltd, The University of Tokyo and National Institute of Advanced Industrial Science and Technology). We reported this system in SAE2012 World Congress. After that, the knowledge management for FTA and new functions of this system have been studied continuously. In this paper we report that FT diagrams used FTAid improved to be useful for design engineers are analyzed based on individual qualification and skill of FTA, we study improvement of FTAid and the FTA education system.
2014-04-01
Technical Paper
2014-01-0724
Derek R. Braden, David M. Harvey
Abstract There is a continual growth of test and validation in high reliability product applications such as automotive, military and avionics. Principally this is driven by the increased use and complexity of electronic systems deployed in vehicles, in addition to end user reliability expectations. Higher reliability expectations consequently driving increased test durations. Furthermore product development cycles continue to reduce, resulting in less available time to perform accelerated life tests. The challenge for automotive electronic suppliers is performing life tests in a shorter period of time whilst reducing the overall associated costs of validation testing. In this paper, the application of prognostic and health monitoring techniques are examined and a novel approach to the validation and testing of automotive electronics proposed which it is suggested may be more cost effective and efficient than traditional testing.
2014-04-01
Journal Article
2014-01-0282
Alex Beresnev, Max Beresnev
The article provides the rationale for, and describes a new internal combustion engine (ICE) diagnosing method, which involves obtaining a signal within the audio frequency range and its examination together with engine performance through the use of algorithms of high resolution time-and-frequency analysis and techniques involving partial signal reconstruction in the phase space. Examples of how the method may be applied to reveal defects and faults of various units and systems are also described in the article. The paper shows that the method may also be used for other assemblies and units of cars (apart from engines) to analyze patterns for periodic wave structures.
2014-04-01
Journal Article
2014-01-0284
Håkan Warnquist, Mattias Nyberg, Jonas Biteus
When a truck or bus suffers from a breakdown it is important that the vehicle comes back on the road as soon as possible. In this paper we present a prototype diagnostic decision support system capable of automatically identifying possible causes of a failure and propose recommended actions on how to get the vehicle back on the road as cost efficiently as possible. This troubleshooting system is novel in the way it integrates the remote diagnosis with the workshop diagnosis when providing recommendations. To achieve this integration, a novel planning algorithm has been developed that enables the troubleshooting system to guide the different users (driver, help-desk operator, and mechanic) through the entire troubleshooting process. In this paper we formulate the problem of integrated remote and workshop troubleshooting and present a working prototype that has been implemented to demonstrate all parts of the troubleshooting system.
2014-04-01
Journal Article
2014-01-0280
Rui Chen, Xinlei Wang
Abstract In this paper, a model-based diagnostic system was developed to detect and isolate the dosing fault and the outlet NOx sensor fault for the SCR system. The dosing fault is treated as an actuator additive fault, while the outlet NOx sensor drift and/or offset fault is treated as a sensor additive fault. First, a 0-D SCR model was developed to facilitate the model-based approach. A parity equation residual generator was designed based on the linearized SCR model and the fault transfer function matrix. The diagnostic algorithm is then implemented in the Matlab/Simulink environment for validation. A high fidelity nonlinear 1-D SCR model is used to generate system outputs and to simulate the plant. The simulation results show that the model-based fault diagnosis system succeeds in detecting and isolating the outlet NOx sensor and dosing faults with good sensitivity and robustness
2014-04-01
Technical Paper
2014-01-0281
Peter Subke
Abstract In the past, the automotive industry has learned the lesson that competition on the level of bits and bytes, proprietary bus systems, data communication and diagnostic protocols is unrewarding. Too much time and money has been spent on the development of proprietary diagnostic tools. Vehicle manufacturers and suppliers realized that standardization would be the best way to overcome this situation. Furthermore, regulatory requirements in the US and the EU for such standardization have strengthened this lesson. As a result, the automotive industry has standardized the technology for the communication of external test equipment with electronic control units (ECUs) in road vehicles. Standardization serves the price, the quality and the maintainability via scale and training curve effects.
2014-04-01
Technical Paper
2014-01-0278
Olof Lindgarde, Rune Prytz
Abstract This paper presents an approach to fault detection and isolation that is based on off-board 1D simulation tools such as GT-power or AVL Boost. The proposed method enables engineers to develop diagnostic functions early on in a development project. The proposed algorithm is evaluated based on measurements from the air path system of the new Volvo FH truck. The results are encouraging. The paper discusses pros and cons of the method and concludes that it has clear potential to be used for on-board diagnostics.
2014-04-01
Journal Article
2014-01-0279
Rasoul Salehi, Aria Alasty, Gholam-Reza Vossoughi
Proper operation of an internal combustion engine is required by demands of a vehicle driver and governmental legislations. Therefore it is necessary to monitor, within an online technique, the engine and detect any fault which disrupts its normal operation. In this paper, the air-charge path, as a key element in a turbocharged engine, is monitored for an air leakage fault. At first, a robust algorithm to estimate unmeasured turbocharger rotational speed is presented. The sliding mode methodology is used to design the estimator which is shown to be robust to the compressor modeling uncertainties. The estimation error from the sliding mode observer (SMO) is then used to detect abnormal behavior of the turbocharger along with the engine due to a leakage fault in the air-charge path. Experimental results from a modern turbocharged SI engine indicate the designed monitoring technique is able to detect a leakage fault, of 7 mm or higher sizes, in the air-charge path.
2014-04-01
Technical Paper
2014-01-0291
Gopal Athani, Prasad Yerraguntla, Anand Gajaraj, Kapil Dongare
Abstract Micro Hybrid Systems are a premier approach for improving fuel efficiency and reducing emissions, by improving the efficiency of electrical energy generation, storage, distribution and consumption, yet with lower costs associated with development and implementation. However, significant efforts are required while implementing micro hybrid systems, arising out of components like Intelligent Battery Sensor (IBS). IBS provides battery measurements and battery status, and in addition mission critical diagnostic data on a communication line to micro hybrid controller. However, this set of data from IBS is not available instantly after its initialization, as it enters into a lengthy learning phase, where it learns the battery parameters, before it gives the required data on the communication line. This learning period spans from 3 to 8 hours, until the IBS is fully functional and is capable of supporting the system functionalities.
2014-04-01
Journal Article
2014-01-1260
Cosmin Emil Dumitrescu, Christopher Polonowski, Brian T. Fisher, A. S. (Ed) Cheng, Gregory K. Lilik, Charles J. Mueller
Natural luminosity (NL) and chemiluminescence (CL) imaging diagnostics are employed to investigate fuel-property effects on mixing-controlled combustion, using select research fuels-a #2 ultra-low sulfur emissions-certification diesel fuel (CF) and four of the Fuels for Advanced Combustion Engines (FACE) diesel fuels (F1, F2, F6, and F8)-that varied in cetane number (CN), distillation characteristics, and aromatic content. The experiments were performed in a single-cylinder heavy-duty optical compression-ignition (CI) engine at two injection pressures, three dilution levels, and constant start-of-combustion timing. If the experimental results are analyzed only in the context of the FACE fuel design parameters, CN had the largest effect on emissions and efficiency.
2014-04-01
Journal Article
2014-01-1448
Johan Hult, Simon Matlok, Stefan Mayer
A combination of optical and laser based methods have been employed for simultaneously studying fuel jet penetration and ignition behaviour of fuel jets inside the cylinder of a large marine two-stroke diesel engine during operation. Tests were performed on a four-cylinder Diesel engine with a bore diameter of 0.5 meter. Optical access was obtained through a custom designed engine cover. A double pulsed laser was employed for global illumination of the liquid fuel jet. For detection a dual camera set-up was employed, which allowed both simultaneous fuel jet and flame emission imaging, or dual frame fuel jet imaging for velocity measurements. From the data recorded the liquid penetration, jet cone angle, jet penetration velocity, ignition location, ignition time and flame lift-off could be extracted. Data was recorded for two different charge densities and temperatures, for two different atomizer designs, and for two different fuels.
2014-04-01
Journal Article
2014-01-1479
Antonino La Rocca, Gianluca Di Liberto, Paul Shayler, Christopher Parmenter, Mike Fay
The determination of size distribution of soot particles and agglomerates in oil samples using a Nanosight LM14 to perform Nanoparticle Tracking Analysis (NTA) is described. This is the first application of the technique to sizing soot-in-oil agglomerates and offers the advantages of relatively high rates of sample analysis and low cost compared to Transmission Electron Microscopy (TEM). Lubricating oil samples were drawn from the sump of automotive diesel engines run under a mix of light duty operating conditions. The oil samples were diluted with heptane before analysing. Results from NTA analysis were compared with the outputs of a more conventional analysis based on Dynamic Light Scattering (DLS). This work shows that soot-in-oil exists as agglomerates with average size of 115 nm. This is also in good agreement with TEM analysis carried out in a previous work. NTA can measure soot particles in polydisperse oil solutions and report the size distribution of soot-in-oil aggregates.
2013-11-27
Technical Paper
2013-01-2883
Rajesha Kundrukote
A vehicle electronic control unit consists of various high side power stages for driving different loads. Common faults such power stages experience are Short Circuit to Battery (SCB), Short Circuit to Ground (SCG) and Open Load (OL). These faults can occur during either on-state or off-state of power stage output. It is essential to diagnose a fault such as SCB during switch off-state, SCG during switch on-state and OL during both on and off-state of the switch in order to avoid system malfunction, power-stage damage etc. A high-side power-stage mainly consists of a switching power MOSFET and its driver section. Quite often the semiconductor manufacturers provide diagnostic information through a digital status (ST) output. A logic low level on the ST pin indicates a fault. The limitation the ST signal is its inability to distinguish faults SCG, SCB and OL. For high-side switches (HSS), to overcome these drawbacks, there is a need of proper diagnosing technique.
2013-10-14
Journal Article
2013-01-2544
Chao Liu, Changfu Zong, Lei He, Chunshan Li, Minghui Liu
A fault detection and diagnosis (FDD) algorithm of 4WID/4WIS Electric Vehicles has been proposed in this study aiming to find the actuator faults. The 4WID/4WIS EV is one of the promising architectures for electric vehicle designs which is driven independently by four in-wheel motors and steered independently by four steering motors. The 4WID/4WIS EVs have many potential abilities in advanced vehicle control technologies, but diagnosis and accommodation of the actuator faults becomes a significant issue. The proposed FDD approach is an important part of the active fault tolerant control (AFTC) algorithm. The main objective of the FDD approach is to monitor vehicle states, find the faulty driving motor and then feedback fault information to the controller which would adopt appropriate control laws to accommodate the post-fault vehicle control system.
2013-10-07
Technical Paper
2013-36-0248
Hélio Rocha Pegorer, João Vilan Júnior, Max Mauro Dias Santos
The increasing application of embedded electronic components in vehicles brings the need to use diagnostic systems for track and control of parameters. Development, manufacturing and after-sales are all fields that use diagnostic systems' help to execute their tasks. Applying communication protocols such as KWP2000, SAEJ1939/73 and UDS makes diagnostic device and automotive network communicate to each other according to standards. This work aims to present an overview about a few communication protocols for diagnostic and services, by showing their specific tools and applications.
2013-10-07
Technical Paper
2013-36-0228
Fernanda Meneses Kelly, Helaine Maria Braga Sbampato
On cab-over trucks to access the engine and others components it is necessary to tilt the cab. This is a regular procedure done several times during the vehicle life cycle. In order to make it easier and safer for mechanical tilting system, it was developed an articulated safety bar to sustain and maintain the cab on the open position. On the current bars available in the market, to close the cab it is necessary that the operator get under the cab to disengage the safety bar. This procedure puts the operator under risk because an accident can happen while the disengagement and the cab can close over him. Thinking on that and looking for a better ergonomic and safety situation, the objective of this work is to present a new articulated safety bar that the engagement and disengagement is done automatically with the natural tilting movement of the cab. This solution was developed at Iveco Latin America for adoption on the new Vertis HD and is under patent process.
2013-09-24
Journal Article
2013-01-2408
Arnold Taube, Michael Mercier
Adoption of a new Electronic Systems Computer-Aided Design (ECAD) system for modeling electrical systems design by Product Engineering offers the promise of improved accuracy and productivity for Service Publication's authors to create wiring diagrams and to standardize their format; while improving the comprehension and functionality of those documents for service technicians. It is also potentially disruptive, requiring new workflows, processes, standards and lines of communication to be developed. This paper describes how to structure and organize a project for effectively and efficiently bringing a new ECAD system for modeling electrical system design into Service Publications. It also provides insight into some lessons learned.
2013-09-24
Journal Article
2013-01-2409
Tomi Krogerus, Mika Hyvönen, Kalevi Huhtala
In this paper, the operating states of a wheel loader were studied for diagnostics purposes using a real time simulation model of an articulated-frame-steered wheel loader. Test drives were carried out to obtain measurement data, which were then analyzed. The measured time series data were analyzed to find the sequences of operating states using two different data sets, namely the variables of hydrostatic transmission and working hydraulics. A time series is defined as a collection of observations made sequentially in time. In our proposed method, the time series data were first segmented to find operating states. One or more segments build up an operating state. A state is defined as a combination of the patterns of the selected variables. The segments were then clustered and classified. The operating states were further analyzed using the quantization error method to detect anomalies.
2013-09-20
Journal Article
2013-01-9041
Shawki Abouel-Seoud, Mohamed Khalil, Sameh Metwalley, Essam Allam, Hany Assad
Reliability has always been an important aspect in the assessment of industrial products and/or equipments. Good product design is of course essential for products with high reliability. However, no matter how good the product design is, products deteriorate over time since they are operating under certain stress or load in the real environment, often involving randomness. Maintenance has, thus, been introduced as an efficient way to assure a satisfactory level of reliability during the useful life of a physical asset. The earliest maintenance technique is basically breakdown maintenance (also called unplanned maintenance, or run-to-failure maintenance), which takes place only at breakdowns. A later maintenance technique is time-based preventive maintenance (also called planned maintenance), which sets a periodic interval to perform preventive maintenance regardless of the health status of a physical asset. The vehicle component is judged to be safe depending on its reliability.
2013-09-17
Journal Article
2013-01-2183
Joao Pedro Pinheiro Malere, Luis Gustavo dos Santos
1 The current pressure across the entire aerospace industry to reduce operating costs and increase efficiency has arguably never been greater. Thus the need to improve parameters such as availability and reliability, and increase the tools and services associated with more efficient aircraft operations and sustainment is now paramount. Moreover, these improvements are seen by many as important factors that define the differentiation and competitiveness of not only current but also future aircraft fleets. The paper will focus on some of the opportunities for OEMs that arise from implementing Integrated Vehicle Health Management (IVHM) systems on their platforms and the challenges associated with evaluating the costs and benefits of their implementation and operation.
2013-09-17
Technical Paper
2013-01-2182
Marc Olivas, Jérôme Genoulaz, Luca Incarbone
In this paper, we present a new application of electromagnetic topology to model the channel formed by an aircraft harness to develop fault detection and localization. This method allows the numerical simulation of reflectometry signals for any kind of wired uniform and non-uniform.
2013-09-17
Journal Article
2013-01-2145
Jonathan L. Geisheimer, David Kwapisz, Thomas Holst, Michael Hafner
Blade tip clearance is a key design parameter for gas turbine designers. This parameter is often measured during engine testing and development phases as part of design validation but has yet to be utilized during normal engine fleet operation. Although blade tip clearance measurements are often mentioned for fleet operation in the context of active clearance control, the use of blade tip clearance measurements can provide an additional benefit for engine health monitoring. This paper explores the use of blade tip clearance sensors for engine condition monitoring of hot section blades. Blade tip clearance, especially in the first stage turbine, has an impact on exhaust gas temperature. The use of tip clearance measurements can provide supplementary information to traditional EGT measurements by providing a direct measurement of wear on the blade tips.
2013-09-17
Technical Paper
2013-01-2159
Luigi Di Palma, Assunta Sorrentino, Pasquale Vitiello, Carmelo Izzo
The target of this paper is to describe the SHM project developed at CIRA. In order to achieve the low weigh target in the MALE UAV structures, the SHM project has the target to setup a system that, being able to evaluate the current state of the structure, will enable minus conservative assumption in the composite structural design. A lamb wave based procedure has been developed in order to analyze the presence of a barely visible impact defect (BVID). The techniques for the damage detections of composite and metallic structures have been developed through extensive numerical-experimental analysis based on lambwave investigation by using piezoelectric sense- actuators. The use of SHM technology and methodology has shown the possibility to have a significant reduction in the structural weight. The technology has achieved a TRL level between 4 and 5 and in order to achieve a higher TRL a test on a component in relevant environment is planned at the end of 2014.
2013-09-17
Technical Paper
2013-01-2146
William Bense
Operational reliability of aircraft engines can be increased if one can detect signs of damages before failure. Prognosis and Health Monitoring (PHM) consists in detecting these signs, and giving the probability of equipment anomaly at a defined horizon. This article presents a global overview of PHM systems. Using a system engineering approach, the needs and the equipments to monitor are clearly specified. The dedicated algorithms and embedded / ground systems split are then defined. Embedded system is mainly limited to data acquisition and data reduction. Ground system contains most of the algorithmic part. First, embedded indicators are normalized in order to be compared flight by flight. Then several kinds of approach can be applied to these indicators: among them, trend analysis toward a predefined threshold or anomaly detection. When an anomaly is detected, a classification algorithm identifies failure signature and associated equipment.
2013-09-17
Technical Paper
2013-01-2238
Manoj Radle, Biswadip Shome
Liquid ring pumps are used in aircraft fuel systems in conjunction with main impeller pumps. These pumps are used for priming the pump system as well as to remove fuel vapor and air from the fuel. Prediction of cavitation in liquid ring pumps is important as cavitation degrades the performance of these pumps and leads to their failure. As test based assessment of cavitation risk in liquid ring pump is expensive and time consuming, recent approaches have been to assess and predict the risk of cavitation using Computational Fluid Dynamics (CFD) methods with the goal to quicken the design process and optimize the performance of these pumps. The present study deals with the development and assessment of a CFD methodology to simulate cavitation for a liquid fuel pump used in aircraft fuel systems. The study simulates the cavitation phenomena using a multi-phase flow model consisting of fuel vapor, air, and liquid fuel phases.
Viewing 151 to 180 of 4788