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Technical Paper

A discussion on fault prognosis/prediction and health monitoring techniques to improve the reliability of aerospace and automotive systems

2018-09-03
2018-36-0316
Currently, aerospace and automotive industries are developing complexand/or highly integrated systems, whose services require greater confidence to meet a set of specifications that are increasingly demanding, such as successfully operating a communications satellite, a commercial airplane, an automatic automobile, and so on. To meet these requirements and expectations, there is a growing need for fault treatment, up to predict faults and monitor the health of the components, equipment, subsystems or systems used. In the last decades, the approaches of 1) Fault Prevention, 2) Fault Detection/Tolerance and 3) Fault Detection/Correction have been widely studied and explored.
Technical Paper

A discussion on the interaction between Project Management and Systems Engineering to improve the Dependability of Space and Automotive Projects

2017-11-07
2017-36-0373
Complex and/or highly integrated systems require the evaluation of Dependability (Reliability, Maintainability, Availability, etc.) throughout their life cycle. The designs of these systems have three main sets of activities: managerial, technical and quality. The recent literature suggests that: 1) the growth of the committed project cost is much greater than the cost spent in the initial stages; and also, the cost to eliminate the defects is smaller in the initial stages of project; and 2) the functions, responsibilities, and authorities of Project Management and Systems Engineering are strongly coupled. Thus, based on the recent literature and the INPE´s (National Institute for Space Research) experience, this paper will show a discussion on the interaction between Project Management and Systems Engineering to improve the Dependability of space and automotive projects.
Technical Paper

Coordination and Synchronization in the Internet of Things: Design Issues for Real-time Applications

2017-11-07
2017-36-0431
Internet of Things (IoT) for real-time applications are demanding more and more high performance, precision, accuracy, modularity, integration, dependability and other attributes in a complex and/or highly integrated environment. Such systems need to provide coordination among the integrated components (e.g. sensors, computer, controller and networks) for enabling the application to take real-time measurements and to translate into controllable, observable and smart actions with strict timing requirements. Therefore, coordination and synchronization are required to ensure the controllable, observable and smart actions of real-time IoT systems. This paper shows the design issues about the coordination and synchronization in the internet of things applied to real-time applications. We also show the current coordination and synchronization techniques and their design issues when applied to IoT systems.
Technical Paper

A Discussion on Time Synchronization and their Effects in Distributed Cyber-Physical Control Systems

2016-10-25
2016-36-0293
Cyber-physical systems are joint instances of growing complexity and high integration of elements in the information and physical domains reaching high levels of difficulty to engineer an operate them. This happens with satellites, aircraft, automobiles, smart grids and others. Current technologies as computation, communication and control integrate those domains to communicate, synchronize and operate together. However, the integration of different domains brings new challenges and adds new issues, mainly in real time distributed control systems, beginning with time synchronization. In this paper, we present a discussion on time synchronization and their effects in distributed cyber-physical control systems. To do that, we review the literature, discuss some time synchronization techniques used in cyber-physical systems, and illustrate them via model and simulation of a system representative of the aerospace area.
Technical Paper

A First Strategy for Smoothing Transients in Switching Controls of Aerospace and Automotive Systems

2016-10-25
2016-36-0402
Switching controls are those that can switch between control or plant modes to perform their functions. They have the advantage of being simpler to design than an equivalent control system with a single mode. However, the transients between those modes can introduce steps or overshootings in the state variables, and this can degrade the performance or even damage the control or the plant. So, the smoothing of such transients is vital for their reliability and mantainability. This is can be of extreme importance in the aerospace and automotive fields, plenty of switchings between manual and autopilot modes via relays, or among gears via clutches, for example. In this work, we present a first strategy for smoothing transients in switching controls of aerospace and automotive systems.
Technical Paper

A Discussion on the Methods of Thermal Cycling and Power Cycling for Reliability Prediction of Solder Joints of Electronic Components

2015-09-22
2015-36-0553
The increasing use of embedded electronics in aerospace and automotive vehicles increases the designers' concern regarding the reliability of the components as well as the reliability of their interconnections. The discussion about the most appropriate method for assessing the reliability of solder joints for a given application is an ever-present theme in the literature. Several methods of prediction have been developed for assessing the reliability of solder joints. The standard method established by the industries for assessing reliability of solder joints is the thermal cycling. However, when the thermal distributions in real applications are studied, particularly in some electronic components used in on-board electronics of space systems, the thermal cycling does not represent what actually happens in practice in the packaging.
Technical Paper

Reconfiguration of Control Systems as Means for Reaching Fault Tolerance: An Assessing Study on Methods Available

2013-10-07
2013-36-0639
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.
Technical Paper

Refinements of the Kalman Estimates for the Position and Velocity of a Vehicle Obtained with GPS Using Inertial Navigation System's Measurements: A Comparative Analysis

2013-10-07
2013-36-0650
Currently, the use of Global Navigation Satellite Systems-GNSS has been widely disseminated for the most different applications, from the aeronautical navigation to the car traffic, being the Global Positioning System-GPS the most used system for such objectives. New applications have presented challenges in terms of the main requirements associated to such systems, namely: precision, reliability, availability, continuity and integrity. It is because proposed solutions, such as satellite or ground-based augmentation systems, depend on signals provided by the GNSS satellite constellation. It constitutes a limitation for using such systems for position and velocity estimations. On other hand, Inertial Navigation Systems-INS, being independent of external signals, have a big potential to be applied on these circumstances; furthermore, they present characteristics that may be considered complementary to the GNSS.
Technical Paper

An Overview of Models, Methods and Tools for Verification, Validation and Accreditation of Real Time Critical Software

2013-10-07
2013-36-0530
Real-time critical systems are those whose failures may cause loss of transactions/data, missions/batches, vehicles/properties, or even people/human life. Accordingly, some regulations prescribe their maximum acceptable probability of failures to range from about 10−4 to 10−10 failures per hour. Examples of such systems are the ones involving nuclear plants, aircrafts, satellites, automobiles, or traffic controls. They are becoming increasingly complex and/or highly integrated as prescribed by the SAE-ARP-4754A Standard. Those systems include, most of the time, real time critical software that must be specified, designed, implemented, validated, verified and accredited (VVA). To do that, models, specially the V-Model, are frequently adopted, together with methods and tools which perform software VVA to ensure compliance (of correctness, reliability, robustness, etc.) of software to several specific standards such as DO178-B/DO-178C (aviation) or IEC 26262 (automotive) among others.
Technical Paper

An Overview of an Assurance Process of Immunity of Embedded Electronic Systems to Single Event Upsets Caused by Ionizing Particles

2013-10-07
2013-36-0535
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.
Technical Paper

An Overview of Clock Synchronization Algorithms and their Uses in Aerospace and Automotive Systems

2013-10-07
2013-36-0541
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.
Technical Paper

The Phases of Systems Engineering at INPE

2012-10-02
2012-36-0482
Since its introduction at INPE, in the late 1960s, Systems Engineering has passed through phases of greater and lesser importance. Three different phases are clearly recognized. The first two phases are closely associated with efforts to develop space systems. The third and present phase is associated to the recent growth in the importance of Systems Engineering to the development of the contemporary large and complex systems. This paper is a summary review of the history of Systems Engineering at INPE from its inception to the present.
Technical Paper

A Discussion on Methods Used in the Verification and Validation of Control Systems Architectures of Cyber-Physical Systems Based on Models and Systems Metrics

2012-10-02
2012-36-0458
The architecture is a concept very broad and important that is directly connected to the realization of a system. It defines what the system is capable of doing, how it accomplishes its mission and how the system is. Currently, the development of system architectures is considered a domain of knowledge where science meets art. In some specific areas, the methods on the development of system architectures are already well formalized. However, when analyzing the evaluation of system architectures such as those for multi-domain control systems, it is clear that there is still much room for rationalization. In these cases, the search for new methods for the evaluation of system architectures is currently in the state of art. In this work we discuss methods used in the verification and validation of control systems architectures of cyber-physical systems based on models and systems metrics.
Technical Paper

An Investigation on Techniques for Accurate Phase or Time Synchronization in Reconfigurable Control Systems

2012-10-02
2012-36-0398
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-4754 Standard. Such systems and their control systems use many modes of operation and many forms of redundancy to achieve high levels of performance and high levels of reliability under changing environments and phases of their lifecycle. The environment disturbances, environment variability, plant non-linear dynamics, plant wear, plant faults, or the non-symmetric plant operation may cause de-synchronization in phase or time among: 1) simultaneous units in the same normal mode of operation; 2) successive units in successive normal modes of operation; 3) main and spare units from normal to faulty modes of operation. So, techniques to reduce those causes or their effects are becoming important aspects to consider in the design of such systems.
Technical Paper

A Discussion on the Standard SAE-ARP-4754A and a Proposal for Using it in Product Certification and Qualification of Staff

2012-10-02
2012-36-0572
Systems such as satellites, aircrafts, automobiles and air traffic controls are becoming increasingly complex and/or highly integrated, as prescribed by the standard SAE-ARP 4754A Standard. They integrate many technologies and they work in very demanding environments, sometimes with little or no maintenance, due to the severe conditions of operation. To survive such harsh operating conditions, they require very high levels of dependability, to be reached by a diversity of approaches, processes, components, etc. Some are suggested by the SAE-ARP-4754A as one of the highest level standards to be met. So, it is important to know it and its consequences for product and staff deeply. The aim of this paper is to present: a discussion on the standard SAE-ARP-4754A and a proposal for using it in product certification and qualification of staff.
Technical Paper

A Discussion on Fault Detection, Isolation, Identification and Reconfiguration in Networked Control Systems of Aerospace Vehicles

2011-10-04
2011-36-0088
In this work, the problem of fault detection, isolation, and reconfiguration (FDIR) for Networked-Control Systems (NCS) of aerospace vehicles is discussed. The concept of fault-tolerance is introduced from a generic structure, and a review on quantitative and qualitative methods (state estimation, parameter estimation, parity space, statistic testing, neural networks, etc.) for FDIR is then performed. Afterwards, the use of networks as loop-closing elements is introduced, followed by a discussion on advantages (flexibility, energy demand, etc.) and challenges (networks effects on performance, closed-loop fault-effects on safety, etc.) represented thereby. Finally, examples of applications on aerospace vehicles illustrate the importance of the discussion herein exposed.
Technical Paper

Current Trends Driving the Aerospace and Automotive Systems Architectures

2011-10-04
2011-36-0387
In this work we discuss current trends driving the aerospace and automotive systems architectures. This includes trends as: 1) pos-globalization and regionalization; 2) the formation of knowledge oligopolies; 3) commonality, standardization and even synergy (of components, tools, development process, certification agents, standards); 4) reuse and scalability; 5) synergy of knowledge and tools convergence; 6) time, cost and quality pressures and innovation speed; 7) environmental and safety issues; and 8) abundance of new technologies versus scarcity of skilled manpower to apply them.
Technical Paper

The Use of PLL Techniques for Accurate Time or Phase Synchronization in Aerospace and Automotive Systems

2011-10-04
2011-36-0179
Current systems such as satellites, aircrafts, automobiles, turbines, wind power generators and traffic controls are becoming increasingly complex and/or highly integrated as prescribed by the SAE-ARP-4754 Standard. Such systems frequently require accurate generation, distribution and time or phase synchronization of signals with different frequencies that may be based on one reference signal and frequency. But the environment fluctuations or the non-linear dynamics of these operations cause uncertainties (skew and jitter) in the phase or time of the reference signal and its derived signals. So, techniques to reduce those causes or their effects are becoming important aspects to consider in the design of such systems. The PLL techniques are useful for establishing coherent phase or time references, jitter reduction, skew suppression, frequency synthesis, and clock recovery in numerous systems such as communication, wireless systems, digital circuits, rotors, and others.
Technical Paper

The Introduction of Systems Engineering into Brazil

2011-10-04
2011-36-0183
Systems are becoming increasingly more complex. To follow this increasingly complexity, systems engineering must evolve rapidly with the introduction of new methodologies, processes, tools, etc. Due to this rapid evolution, little attention is dedicated to the study of the history of its evolution. Currently there is the initiative of installation of a chapter of INCOSE (International Council on Systems Engineering) in Brazil and from this initiative emerged the interest of recovering the history of systems engineering in the country. There are indications that the introduction of systems engineering into Brazil occurred in the late 1960's, directly from NASA and that its first applications in Brazil were in Space Systems Engineering. This paper recovers the origins of systems engineering, of its introduction into Brazil, and of its use in space systems engineering.
Technical Paper

The Application of a Requirements Traceability Automation Tool to the Documentation of a Satellite Project

2010-10-06
2010-36-0345
This paper presents the preliminary results of an "a posteriori" exercise of application of a Requirements Traceability Automation Tool (RT tool) to a set of documents. The documents have been prepared according to established Space System Engineering methodologies and with attention to text quality, but without attention to requirements traceability because the processes and methodologies used during their preparation predates the emergence of the processes and methodologies developed by Requirements Engineering (RE). This study is intended to determine some of the benefits of using a RT tool when compared with the previously used processes and methodologies. The set of documents under scrutiny have been prepared in the frame of the development of the CBERS-3 satellite (China-Brazil Earth Resources Satellite) and is composed of system, subsystem and equipment specification and covering documents related to the Electrical Power Subsystem (EPS) of the satellite.
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