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Viewing 1 to 30 of 9316
2010-10-25
Journal Article
2010-01-2203
Johan Wahlström, Lars Eriksson
In diesel engines with EGR and VGT, the gas flow dynamics has significant nonlinear effects. This is shown by analyzing DC-gains in different operating points showing that these gains have large variations. To handle these nonlinear effects, a nonlinear state dependent input transformation is investigated. This input transformation is achieved through inversion of the models for EGR-flow and turbine flow. It is shown that the input transformation handles the nonlinear effects and decreases the variations in DC-gains substantially. The input transformation is combined with a new control structure that has a pumping work minimization feature and consists of PID controllers and min/max-selectors for coordinated control of EGR-fraction and oxygen/fuel ratio. The EGR flow and the exhaust manifold pressure are chosen as feedback variables in this structure. Further, the set-points for EGR-fraction and oxygen/fuel ratio are transformed to set-points for the feedback variables.
2010-10-25
Technical Paper
2010-01-2210
Withit Chatlatanagulchai, Nitirong Pongpanich, Krisada Wannatong, Shinapat Rhienprayoon
In this paper, we investigate a multivariable control of air path of a diesel-dual-fuel (DDF) engine. The engine is modified from a CI engine by injecting CNG in intake ports. The engine uses CNG as its primary fuel and diesel as its secondary fuel, mainly for initiation of combustion. The modification is economically attractive because CNG has lower price than diesel and the modification cost is minimal. However, for DDF engine, control of the air path becomes more difficult because the engine now has combined characteristics of the CI and the SI engines. The combined characteristics come from the fact that diesel is still directly injected into cylinders (CI engine) while CNG is injected at the intake ports (SI engine.) In pure CI engine, throttle is normally fully opened for maximum air intake, while EGR valve is actively actuated to obtain low emissions. In pure SI engine, however, throttle is an active actuator, driven by pedal.
2010-10-25
Technical Paper
2010-01-2211
Fabrizio Ponti, Vittorio Ravaglioli, Davide Moro, Gabriele Serra
Proper design of the combustion phase has always been crucial for Diesel engine control systems. Modern engine control strategies' growing complexity, mainly due to the increasing request to reduce pollutant emissions, requires on-board estimation of a growing number of quantities. In order to feedback a control strategy for optimal combustion positioning, one of the most important parameters to estimate on-board is the angular position where 50% of fuel mass burned over an engine cycle is reached (MFB50), because it provides important information about combustion effectiveness (a key factor, for example, in HCCI combustion control). In modern Diesel engines, injection patterns are designed with many degrees of freedom, such as the position and the duration of each injection, rail pressure or EGR rate. In this work a model of the combustion process has been developed in order to evaluate the energy release within the cylinder as a function of the injection parameters.
2010-10-25
Technical Paper
2010-01-2220
Alessandro di Gaeta, Umberto Montanaro, Veniero Giglio
Idle Speed Control plays a crucial role to reduce fuel consumption that turns in both a direct economic benefit for customers and CO\d reduction particularly important to tackle the progressive global environmental warming. Typically, control strategies available in the automotive literature solve the idle speed control problem acting both on the throttle position and the spark advance, while the Air-Fuel Ratio (AFR), that strongly affects the indicated engine torque, is kept at the stoichiometric value for the sake of emission reduction. Gasoline Direct Injection (GDI) engines, working lean and equipped with proper mechanisms to reduce NOx emissions, overcome this limitation allowing the AFR to be used for the idle speed regulation.
2010-10-25
Journal Article
2010-01-2091
Michael J. Lance, C. Scott Sluder, Samuel Lewis, John Storey
Exhaust gas recirculation (EGR) cooler fouling has become a significant issue for compliance with nitrogen oxides (NOx) emissions standards. In order to better understand fouling mechanisms, eleven field-aged EGR coolers provided by seven different engine manufacturers were characterized using a suite of techniques. Microstructures were characterized using scanning electron microscopy (SEM) and optical microscopy following mounting the samples in epoxy and polishing. Optical microscopy was able to discern the location of hydrocarbons in the polished cross-sections. Chemical compositions were measured using thermal gravimetric analysis (TGA), differential thermal analysis (DTA), gas chromatography-mass spectrometry (GC-MS), x-ray photoelectron spectroscopy (XPS), energy dispersive spectroscopy (EDS) and x-ray diffraction (XRD). Mass per unit area along the length of the coolers was also measured.
2010-10-25
Journal Article
2010-01-2254
Russell P. Fitzgerald, Richard R. Steeper
An infrared laser absorption technique has been developed to measure in-cylinder concentrations of CO in an optical, automotive HCCI engine. The diagnostic employs a distributed-feedback, tunable diode laser selected to emit light at the R15 line of the first overtone of CO near 2.3 μm. The collimated laser beam makes multiple passes through the cylinder to increase its path length and its sampling volume. High-frequency modulation of the laser output (wavelength modulation spectroscopy) further enhances the signal-to-noise ratio and detection limits of CO. The diagnostic has been tested in the motored and fired engine, exhibiting better than 200-ppm sensitivity for 50-cycle ensemble-average values of CO concentration with 1-ms time resolution. Fired results demonstrate the ability of the diagnostic to quantify CO production during negative valve overlap (NVO) for a range of fueling conditions.
2010-04-12
Journal Article
2010-01-0451
Christoph Roth, Oliver Sander, Michael Hübner, Juergen Becker
A future car-to-x communication system has to fulfil a lot of different requirements concerning high performance and functionality that are given by the field of application. To be able to optimize the system architecture regarding these constraints an intensive architecture evaluation and investigation is necessary. Within this paper a simulative approach for comprehensive design space exploration, verification, and test of a car-to-x communication unit is presented. The proposed simulation environment allows for a flexible adaption to the test case by being able to interconnect an arbitrary number of simulators of different type and different granularity. As a novelty complete embedded car-to-x systems can be investigated by integrating several SystemC based architecture models into an environmental simulation and observing their behavior and interaction.
2013-04-08
Journal Article
2013-01-1230
Steffen Ostendorff, Joerg Sachsse, Heinz-Dietrich Wuttke, Jorge Meza Escobar
This paper presents an adaptive test approach to improve the structural testing of printed circuit boards (PCB) found in electronic automotive components. The approach makes use of FPGAs available on the PCBs, and its applicability is supported by the global trend taking place in the automotive industry of replacing ASICs with programmable devices such as FPGAs. For structural testing of PCBs, Boundary Scan (BScan) is mostly used. However, BScan has the disadvantage of being a static test method due to the slow execution speed reducing the fault coverage concerning dynamic faults. FPGAs support BScan as well, but they also offer a vast number of programmable resources. These resources can be configured for testing purposes. Our approach is to speed-up the testing process during the PCB manufacturing by moving data intensive processing from the external software side (Test-PC) to the programmable hardware side on-board (FPGA), reducing the data transfer over the slow JTAG interface.
2013-04-08
Technical Paper
2013-01-1233
Sreegururaj Jayachander
The current trend of going “green” in emerging automotive markets is, by the conversion of internal combustion engine based vehicle platforms into electrified vehicle platforms. While this method of electrification reduces the product development life cycle drastically due to the availability of a readymade platform, there are certain areas that are always overlooked. While focus is given on obvious and necessary elements like power train & battery packaging, weight reduction, high voltage safety, thermal management etc., electro-magnetic compatibility is neglected in the conversion process. This paper shall describe, in detail and in particular, the effect of electrical transients created by legacy elements, already existing in the baseline platform. This is an outcome of electro-magnetic compatibility challenges faced during the conversion of an internal combustion engine powered vehicle into an electric vehicle.
2013-04-08
Journal Article
2013-01-1228
Graciela Becci, Gunwant Dhadyalla, Alexandros Mouzakitis, James Marco, Andrew David Moore
Testing real-time vehicular systems challenges the tester to design test cases for concurrent and sequential input events, emulating unexpected user and usage profiles. The vehicle response should be robust to unexpected user actions. Sequence Covering Arrays (SCA) offer an approach which can emulate such unexpected user actions by generating an optimized set of test vectors which cover all possible t-way sequences of events. The objective of this research was to find an efficient nonfunctional sequence testing (NFST) strategy for testing the robustness of real-time automotive embedded systems measured by their ability to recover (prove-out test) after applying sequences of user and usage patterns generated by combinatorial test algorithms, considered as “noisy” inputs. The method was validated with a case study of an automotive embedded system tested at Hardware-In-the-Loop (HIL) level. The random sequences were able to alter the system functionality observed at the prove-out test.
2013-04-08
Technical Paper
2013-01-1229
Ajinkya Chinchwadkar, Alok Khare
Currently, OEMs worldwide are emphasizing more upon development and implementation of new electrical features on existing vehicles [3]. However, development and implementation of new electrical features on existing vehicle platforms create architectural as well as packaging challenges. These challenges are augmented due to following: the need to implement such features across different body styles of vehicles that are based on same or different architectures different requirement for a feature based upon market requirement This paper analyzes these challenges to help in providing design solutions for successful implementation of new features as per following requirements: 1 Provide optimum design to have low cost and high quality for existing vehicle platforms2 Provide spare capacity while designing new vehicles or architectures
2004-07-19
Technical Paper
2004-01-2478
Richard Boulanger, David Overland
Technologies that facilitate the design and control of complex, hybrid, and resource-constrained systems are examined. This paper focuses on design methodologies, and system architectures, not on specific control methods that may be applied to life support subsystems. It has been estimated that 60–80% of the effort in developing complex control systems is software development, and only 20–40% is control system development [1]. It has also been shown that large software projects have failure rates of as high as 50–65% [2,3]. Concepts discussed include the Unified Modeling Language (UML) and design patterns with the goal of creating a self-improving, self-documenting system design process. Successful architectures for control must not only facilitate hardware to software integration, but must also reconcile continuously changing software with much less frequently changing hardware [4]. These architectures rely on software modules or components to facilitate change.
2004-07-19
Technical Paper
2004-01-2457
Jeffery T. Iverson, Thomas M. Crabb, Mark C. Lee, Bill Butrymowicz
Unique challenges arise during the design of temperature and humidity control systems (THCS) for use in microgravity. The design of the Plant Research Unit’s (PRU) THCS builds on the experience gained during the Biomass Production System (BPS) project and extends the understanding of the critical design variables and necessary technical advancements to allow for longer on-orbit operation. Previous systems have been limited by loss of prime, clogging in the porous plates and component reliability. Design of THCSs for long-duration space flight experiments requires the mitigation of these issues as well as a complete understanding of the relevant design variables. In addition to the normal design variables (e.g. mass, power, volume), a complex and interdependent relationship exists between the THCS variables including operational temperature range, operational humidity range, required humidity condensation rate and system air flow.
2004-07-19
Technical Paper
2004-01-2456
Jessica J. Prenger, Susan L. Steinberg, Daniel Haddock, Joey H. Norikane, Howard G. Levine
The WONDER space flight experiment will compare the operation of both substrate-based and porous tube nutrient delivery systems (NDS) under microgravity conditions. Each NDS will be evaluated with three moisture availability regimes, and moisture sensing will be critical for the operation and evaluation of the systems. Orbital Technologies (Madison, WI) has developed a space flight-rated temperature and moisture acquisition system (TMAS) for measuring water content of plant growth medium. The sensors were evaluated in 0.25-1 mm and 1-2 mm baked ceramic aggregate (Profile and Turface, respectively). The sensors' pooled standard deviations ranged from approximately 2% to 5% relative water content (RWC), and root mean square error between sensor RWC and measured RWC was greater than 3% using linear calibration.
2004-07-19
Technical Paper
2004-01-2433
J. J. Maas, M. J. Mischnick
The CANDS (Circulating, Aeration, and Nutrient Delivery System) Phase II SBIR is currently developing and testing methods and procedures to control moisture, oxygen, and temperature in the root zone of a particulate based micro-gravity nutrient delivery system. The completion of the first year and a half of the CANDS Phase II SBIR has shown significant engineering developments towards environmental control of the root zone. These developments include the measurement of root zone oxygen content, characterization of forced and flood-ebb aeration rates, successful control of root zone moisture using miniature heat-pulse moisture sensors, and successful control of root zone temperature via an insulating/temperature controlling water jacket. At the conclusion of the CANDS Phase II SBIR an integrated root zone environmental control system will be constructed for integration into plant growth systems to eliminate the uncertainties that exist in current plant growth data.
2004-07-19
Technical Paper
2004-01-2437
Hiroyuki Miyajima, Tomofumi Hirosaki, Yoshio Ishikawa
A Regenerative Life Support System (RLSS) is a system that establishes self-sustained material recycling and circulation within a space base on the Moon or Mars. This is a large-scale and complicated system comprising a lot of components such as humans, plants and material circulation system. A RLSS contains many factors with uncertainty, such as dynamics of plants and humans, and failure and performance deterioration of devices. In addition, a RLSS is a large-scale and complicated system extending gradually. An environment with uncertainty or a large-scale and complicated system may not be properly addressed by a centralized system. In particular, such a system cannot always gather accurate information in one center in a frequently shifting environment, thus appropriate processing may be difficult. Therefore, we tried autonomous decentralization of information or decision-making using a Multi-Agent System (MAS).
2004-07-19
Technical Paper
2004-01-2439
Theresa Klein, Devika Subramanian, David Kortenkamp, Scott Bell
Advanced life support systems have many interacting processes and limited resources. Controlling and optimizing advanced life support systems presents unique challenges that are addressed in this paper. We have developed a controller using reinforcement learning [Barto&Sutton], which actively explores the space of possible control strategies, guided by rewards from a user specified long term objective function. We evaluated this controller using Biosim, our discrete event simulation of an advanced life support system. This simulation supports all life support modules including crew, food production, air revitalization, water recovery, solid waste incineration and power. Our algorithm for reinforcement learning discovered unobvious strategies for maximizing mission length. By exploiting nonlinearities in the simulation dynamics, the learned controller outperforms a controller designed by an expert.
2004-07-19
Technical Paper
2004-01-2441
Sherif Abdelwahed, Jian Wu, Gautam Biswas, John W. Ramirez, Eric J.-Manders
This paper discusses a hierarchical online fault-adaptive control approach for Advanced Life Support (ALS) Systems. ALS systems contain a number of complex interacting subsystems. To avoid complexity in the models and online analysis, diagnosis and fault-adaptive control is achieved by local units. To maintain overall performance, the problem of resource management for contending concurrent subsystems has to be addressed. We implement a control structure, where predefined set-point specifications for system operation are used to derive optimizing utility functions for the subsystem controllers. We apply this approach in situations where a fault occurs in a system, and once the fault is isolated and identified, the controllers use the updated system model to derive new set point specifications and utility functions for the faulty system.
2004-07-19
Technical Paper
2004-01-2440
Todd M. Quasny, Larry D. Pyeatt
Abstract To make extended space missions, such as missions to Mars, a reality, an advanced life support system (ALS) must be developed that is able to utilize resources to their fullest capabilities [2]. In order to make such a system a reality, a robust control system must be developed that is able to cope with the complexity of an ALS. This work applies reinforcement learning (RL), a machine learning technique, to the task of controlling the water recovery system of a simulated ALS. The RL agent learns an effective control strategy that extends the mission length to the point that lack of water is no longer the cause of mission termination.
2004-11-02
Technical Paper
2004-01-3092
Zenovy S. Wowczuk, Kenneth H. Means, Victor H. Mucino, Gregory J. Thompson, James Smith, Jeffery R.X Auld, James E. Smith, Adam Naternicola, Lawrence Anthony Feragotti, Bruce J. Corso
The development of a standardized roll-on, roll-off (RoRo) sensor pallet system for a C-130 aircraft was conceived by the National Guard and the Counter Narco-Terrorism Technology Development Office to assist in counterdrug reconnaissance activities within the United States and surveillance and reconnaissance missions worldwide. West Virginia University was contracted to perform the design and development of this system because of their innovative design ideas. Before development, the design parameters were established by these two DoD agencies, their mission requirements and by the limitations of the C-130 aircraft. These limitations include using Commercial off the Shelf (COTS) and Government off the Shelf (GOTS) items when developing the system that must be universal on all C-130 aircrafts variants B thru H. Further design criteria are by the limitations of the C-130 aircraft and its existing mission requirements.
2004-10-18
Technical Paper
2004-21-0001
Richard C. Lind, Huan W. Yen, Douglas L. Welk
The evolution of car radio in the past seven decades is a perfect illustration of the convergence of diverse technical fields: RF electronics, mobile wireless communications, the Internet, personal computers, consumer electronics, and automotive human machine interfaces. The early part of the radio evolution was driven by the need to improve the received audio signal quality while in the past two decades the driver has been to increase the channel capacity and to enhance the degree of personalization. Besides traditional AM/FM programming, today's radios also play a variety of media such as cassette tape, CD, MP3, DVD-A etc. as well as over 100 channels of satellite digital audio programs. Going forward, we believe that the radio will continue to be the entertainment center of the vehicle, and that the consumers are expecting to have access to personalized information anywhere and anytime.
2004-10-18
Technical Paper
2004-21-0006
Lawrence C. Pesce
In the spring of 1991, the business teams of Hughes Communication and Thomson Consumer Electronics asked the question of whether a satellite TV system with an 18″ dish could be a viable consumer product. Would people pay for what was previously “free” and could the market be expanded from the rural un-served to the perceived metro underserved? Betting that consumers would pay for higher quality and more compelling entertainment, the dice was rolled. That bet more than paid off with the satellite TV industry growing to more than twenty million subscribers. Satellite radio now faces the same questions, but history has already passed judgment on its ultimate success. The question is no longer whether it will succeed, but exactly how great is the opportunity. Satellite radio will not only fulfill its promise of offering a wide range of lean back entertainment options, but also the potential for new lean forward services.
2004-11-16
Technical Paper
2004-01-3315
Alexandre de Almeida Guimarães
It is clearly perceived the exponential growth of on-board electronics on several technological segments. On aerospace segment that is not different. Besides those propulsion and navigation fundamentals systems, necessary on most part of the aircrafts, many complex electronic systems are required: for the treatment of information sent by either landed equipments or other aircrafts (often found on military applications), and for comfort and entertainment systems (most related to passenger transportation applications). In any case, the amount of available and exchangeable information between these systems is fairly huge. Such data exchange would be easier performed if were made through the application of a communication protocol. This paper lists and analyses the communication protocols used by most part of the current and future aircrafts. The intention of this document is to be a study guideline of avionics related protocols.
2004-11-16
Technical Paper
2004-01-3348
Marcelo R.A.C. Tredinnick, Marcelo Lopes de Oliveira e Souza
In this work we study the stability of digital controls of flexible/Vibratory aerospace/automobile systems by the graph norm technique, occurring in sampled-data control systems due to sampling period variations. To do so, this work tries to establish regions (graphs) of stability and instability in a Banach Space, the distances (norms) between them and a given design to detect analytically and/or numerically its margins of stability or conditions of instability. Based on that, we sketch the first steps for a design methodology of stable digital controllers of flexible/vibratory systems embedded in a sampled-data system with adjustable sampling periods of A/D and D/A converters. A short tutorial about the graph norm technique is also given and some theoretical results as well numerical results are shown. This work was done in two folds to unmask the stability secrets hidden in a general sampled-data control system, until today not revelated.
2004-11-16
Technical Paper
2004-01-3474
Paulo Henriques Iscold Andrade de Oliveira, Rogério Pinto Ribeiro, Ricardo Luiz Utsch de Freitas Pinto, Luciano Saraiva Resende, Fabrizio Nicolosi, Domenico Pietro Coiro, Nicola Genito
This paper present the instrumentation procedure used in order to determine the performance, stability and control characteristics of the light aircraft CEA-205 CB-9 Curumim. The instrumentation used is: i) autonomous acquisition system using micro controllers; ii) solid state inertial platform; iii) pitot probe; iv) attack and sideslip angle indicators; v) potentiometer on control system; vi) load cell on control system; vii) propeller tachometer; viii) barometer; ix) thermometer and x) GPS. Assembly and calibration detail procedures are presented with some results obtained on typical maneuvers. This work, in development on the Center for Aeronautical Studies of Federal University of Minas Gerais (CEA/UFMG) and on the Department of Aeronautical Engineering of Naples University (DPA), intend to assembly a system in order to perform low cost flight tests on light aircrafts.
2004-07-19
Technical Paper
2004-01-2311
Jih-Run Tsai, Chia-Ray Chen, Lou-Chuang Lee, Chiuder Hsiao, Marco Molina, Maddalena Cova, Alberto Franzoso, Joseph Burger
The thermal vacuum / thermal balance test design and execution are described in the paper for the qualification campaign of 37 electronic units flown with the payload of ISS (International Space Station), i.e., AMS-02 (Alpha Magnetic Spectrometer). The tests are run in 10 separate test campaigns, across a time frame of 3 years (2002–2005). The tests have been carried on at NSPO (National Space Program Office in Taiwan), maximizing the time usage of thermal vacuum facilities. During each experimental campaign several units are tested at the same time, sharing the vacuum chamber volume. Because independent heaters are applied to each unit, the electronic crates can be tested at temperature levels different from one another. The reliability of thermal analysis is enhanced at each thermal balance test, with the final aim to fully validate the thermal mathematical model deviating less than 3°C from actual measurements.
2004-07-19
Technical Paper
2004-01-2306
A. Robson, S. Dolce, P. Ayache
MetOp is a series of three meteorology and climate monitoring satellites, which will be launched using the Russian Soyuz-Fregat vehicle over a period of 14 years starting in 2005. MetOp will form part of the American ‘Polar Orbiting Environmental Satellites’ (POES) programme, a further step in European/American collaboration in space. The MetOp satellites will fly in a sun-synchronous polar orbit at an altitude of between 800 and 850km, with a repeat cycle of 29 days. The satellite is based on the successful Spot platform, which has carried a number of European earth observation satellites over the last 15 years, and consists of two parts: 1. The Payload Module (or PLM) which carries twelve instruments, provided by the European Space Agency (ESA), the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT), the American National Oceanic and Atmospheric Administration (NOAA) and the French space agency, CNES. 2.
2013-10-07
Technical Paper
2013-36-0639
Jairo Eduardo Moraes Siqueira, Marcelo Lopes de Oliveira e Souza
The realization of modern systems subjected to automatic control, such as aircraft, automobiles, satellites, rocket launchers, cargo and military ships, and so forth; increasingly assume, within its very set of requirements, the task of providing better dependability, i.e.: safety, reliability, and availability altogether. Towards this demand, fault-tolerant control greatly meets such growing demand of dependability, by its ability of recognizing the occurrence of potentially hazardous/hazardous faults within the overall (closed-loop) system, and by taking remedial action whenever necessary/mandatory. The process of fault tolerance can be segregated into two fundamental steps: (1) that of fault diagnosis, comprising fault detection-isolation-identification, and, (2) control adjustment/reconfiguration. This paper focuses on the second step, of control adjustment/reconfiguration.
2013-10-07
Technical Paper
2013-36-0541
Eloy Martins de Oliveira Junior, Marcelo Lopes de Oliveira e Souza
Current systems such as satellites, aircrafts, automobiles, turbines, power controls and traffic controls are becoming increasingly complex and/or highly integrated as prescribed by the SAE-ARP-4754a Standard. Such systems operate in a real time distributed environment which frequently requires a common knowledge of time among different devices, levels and granularities. So, temporal correctness is mostly needed, besides logical correctness. It can be achieved by hardware clocks and devices, software clocks and algorithms, or both, to avoid or tolerate, within appropriate margins, the time faults or failures that may occur in aerospace and automotive systems. This paper presents an overview of clock synchronization algorithms and their uses in aerospace and automotive systems. It is based on a review of the literature, discussion and comparison of some clock synchronization algorithms with different policies.
2013-10-07
Technical Paper
2013-36-0535
Sérgio Roberto Ferreira Machado, Marcelo Lopes de Oliveira e Souza
The aerospace and automotive electronic systems are getting more complex and/or highly integrated, as defined by ARP 4754A, making extensive use of microelectronics and digital memories which, in turn, operates in higher frequencies and lower voltages. In addition, the aircraft are flying in higher altitudes, and polar routes are getting more frequent. These factors raise the probability of occurrence of hazardous effects like the Single Event Upsets in their embedded electronic systems. These must be designed in a way to tolerate and assure the immunity to the Single Event Upsets, based upon criteria such as reliability, availability and criticality. This paper proposes an overview of an assurance process of immunity of embedded electronic systems to Single Event Upsets caused by ionizing particles by means of a review of literature and an analysis of standards as ECSS-E-ST-10-1, NASA Single Event Effects Criticality Analysis and IEC TS 62396-1.
Viewing 1 to 30 of 9316

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