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Thermal Management Systems Symposium industry discusses latest regulatory impacts, applications to reduce engine emissions, conserve energy, reduce noise, improve the cabin environment, increase overall vehicle performance passenger, commercial vehicle industry.

Low speed pre-ignition (LSPI) in downsized spark-ignition engines has been studied for more than a decade but no definitive explanation has been found regarding the exact sources of auto-ignition. No single mechanism can explain all the occurrences of LSPI and that each engine should be considered as a particular case supporting different conditions for auto-ignition. In a different context, dual fuel Diesel-Methane engines have been more recently studied in large to medium bore compression ignition engines. However, if Dual Fuel combustion is less knock sensitive, LSPI remains one of the main limitations of low-end torque also for dual fuel engines. Indeed, in some cases, premature ignition of CNG can be observed before the Diesel pilot injection as LSPI can classically be observed before the spark in gasoline engines. This article aims at highlighting the similarities and discrepancies between LSPI phenomena in SI gasoline and dual fuel engines.

The effect of methanol addition (by blending) and methanol induction (by carburetion) on performance of a vegetable oil (Madhuca Indica called as Mahua oil) based diesel engine was studied experimentally. A single cylinder, water cooled, DI, diesel engine was used. Baseline data was generated with neat diesel and neat Mahua oil as fuels. Subsequently methanol was blended with Mahua oil in different proportions such as 5, 10, 15 and 20% by mass and tested for engine's performance. Finally the engine was operated in dual fuel mode of operation with methanol induction and Mahua oil injection. Engine performance, emission and combustion characteristics of ND (neat diesel), NMO (neat Mahua oil), MOMB (Mahua oil+15% methanol blend by mass) and MOMDFE (Mahua oil dual fuel engine at 15% mass share) were compared and analyzed at 100% and 40% loads. NMO resulted in inferior performance and increased emissions at both power outputs as compared to ND.

Safety is a requirement concerning an increasing number of automotive applications. Recent safety standards set requirements for designing safety-critical systems. Among others, these specifications include a comprehensive detection and handling of hardware faults. Currently emerging dual-core microcontrollers provide a cost-effective opportunity to fulfill these requirements. In this paper we analyze a safety-critical application example and discuss two different approaches, an application-specific approach and a generic approach for implementing functional safety requirements on a dual-core microcontroller. An investigation of the associated concepts called function monitoring architectures and generic architectures reveals their differences and at the same time advantages and disadvantages. Besides effects on safety, effects on reliability, modifiability and costs are evaluated and presented graphically.

Since the debut of the spark ignition engines about 150 years ago, the understanding of an engine torque production has been widely investigated in many engine combustion research laboratories around the world. The effects of an engine geometric and operation parameters like, for instance, throttle angle, spark advance, fuel octane rating and compression ratio have been one of the main goals of these studies. A modern torque model based engine control software, which is able to predict and control engine torque for a given operating condition, makes use of these engine researches’ findings. A new variable which has been added recently into the torque generation study is the ethanol content fuel, in order to suit flex fuel engines application. This paper presents the results of an analysis conducted with a flex fuel engine running on Brazilian gasohol (E25) and hydrous ethanol (E100) fuels.

Hazard analysis plays an important role in the development of safety-critical systems. Hazard analysis techniques have been used in the development of conventional automotive systems. However, as future automotive systems become more sophisticated in functionality, design, and applied technology, the need for a more comprehensive hazard analysis approach has arisen. In this paper, we describe a comprehensive hazard analysis approach for system safety programs. This comprehensive approach involves applying a number of hazard analysis techniques and then integrating their results. This comprehensive approach attempts to overcome the narrower scope of individual techniques while obtaining the benefits of all of them.

It is well known the dual fuel operation at lower loads suffers from lower thermal efficiency and higher unburned percentages of fuel. The present work includes a computational investigation to predict the effects of Exhaust gas recirculation (EGR) on the operation of an indirect-injection dual fuel (Ricardo-E6) engine by using a detailed chemical kinetic scheme and a quasi-two zone analytical model. The comprehensive chemical kinetic scheme for methane oxidation consisting of 178 elementary reaction steps with 41 species. A quasi-two zone analytical model is based on the effective energy releases of the pilot diesel fuel while using the detailed chemical reaction kinetic scheme for the oxidation of methane. Through the results, it was shown that, the active species such as H, O and OH produced in the high temperature combustion process and found in the exhaust gases are play a significant role in the preignition reactions.

Ground vehicle dynamic stability, including spinout and rollover, is highly dependent on maneuvering conditions and the nonlinear force response characteristics of tires. Depending on vehicle configuration, unstable behavior requires high, sustained lateral acceleration, and some maneuver induced excitation of the roll and yaw mode dynamics. Dynamic instability in some vehicles can be induced by a steering reversal maneuver that involves sustained limit performance lateral acceleration. Using a validated vehicle dynamics simulation, analysis is presented to illustrate what constitutes a critical stability sensitive maneuver. Two example test cases are used to show that a critical stability sensitive maneuver must be more severe than a single lane change. Even reaching tire saturation limits during an aggressive single lane change does not give the sustained lateral acceleration required to provoke instability conditions.

With the growing complexity and integration of systems as satellites, automobiles, aircrafts, turbines, power controls and traffic controls, as prescribed by SAE-ARP-4754A Standard, the time de-synchronization can cause serious or even catastrophic failures. Time synchronization is a very important aspect to achieve high performance, reliability and determinism in networked control systems. Such systems operate in a real time distributed environment which frequently requires a consistent time view among different devices, levels and granularities. So, to guarantee high performance, reliability and determinism it is required a performance evaluation of time synchronization of the overall system. This time synchronization performance evaluation can be done in different ways, as experiments and/or model and simulation.

Avionics Systems are increasingly used to perform safety-critical functions at high altitudes. But their increasing capacity and concentration of memory and logics leads to more frequent occurrences of single event upsets, especially in high altitudes. In this work we discuss the effects and mitigation of single event upsets on avionics systems to help in developing future requirements. To do that we initially present the concepts of radiation environment of the atmosphere, radiation induced errors, single event upsets, etc. Then, we discuss some of their effects on avionic systems and ways of mitigation. Finally, we discuss provisions to demand the adoption of such mitigation measures, and their sufficiency. This will help in developing future requirements to accomplish the objectives of a safe operation of civil transportation aircraft.

Avionics Systems are increasingly used to perform safety-critical functions at high altitudes. But their increasing capacity and concentration of memory and logics leads to more frequent occurrences of single event upsets, especially in high altitudes. In this work we discuss the process of eliciting and validating requirements to handle single events upsets in avionic systems. To do that we initially summarize and update the concepts of radiation environment of the atmosphere, radiation induced errors, single event upsets, etc. presented in a previous paper. Then, we discuss some of their effects on avionic systems and ways of mitigation, reported in the literature. Finally, we discuss provisions to demand the adoption of such mitigation measures, and their sufficiency by transforming them into requirements, according to recommendations of compliance described in standards as SAE ARP 4754A and RTCA DO-254.

The introduction of drive-by-wire systems into modern vehicles has generated new challenges for the designers of embedded systems. These systems, based primarily on microcontrollers, need to achieve very high levels of reliability and availability, but also have to satisfy the strict cost and packaging constraints of the automotive industry. Advances in VLSI technology have allowed the development of single-chip systems, but have also increased the rate of intermittent and transient faults that come as a result of the continuous shrinkage of the CMOS process feature size. This paper presents a low-cost, fault-tolerant system-on-chip architecture suitable for drive-by-wire and other safety-related applications, based on a triple-modular-redundancy configuration at the processor execution pipeline level.

There is an increasing demand to educate students on systems thinking and systems approaches at undergrad and graduate levels in colleges in India. Efforts are being made by industry, academia, and professional societies to join hands to bridge the gap. Specifically, there is significant emphasis on providing wholistic “live” case studies and examples to students to get their “hands dirty” on actual systems. One of the inhibitors on this aspect being faced, in the aerospace domain, is that actual examples are not available in the open literature as they are considered proprietary and/or confidential. This paper illustrates a framework for educating students on systems approaches and systems thinking in a near “live” scenario through a case of safety critical control system embedded with Artificial Intelligence (AI). With the recent advances in AI and increasing demands on embedding AI in complex aerospace systems, certification of such systems poses many hurdles and challenges.

The integration of safety-critical and major power-consuming electrical systems presents a challenge for the development of future automotive electrical networks. Both reliability and performance must be enhanced in order to guarantee the power supply to essential electrical consumers at a sufficient degree of power quality. Often, in order to cope with these requirements, merely an upgrade of the existing wiring harness design is used, resulting in additional complexity, weight, and cost [3]. A characterization of the wiring harness and its electrical consumers facilitates a systematic optimization approach aimed at designing new automotive power networks [1, 5]. Measurement and analysis methods to characterise the thermal behaviour of the wiring harness have been presented and discussed in a previous paper [4] This paper presents and compares two methods aimed at modeling the electrical behavior of consumers at various voltages and temperatures.

Functional safety requirements and solutions are more expensive when it comes to lower cost machines with less power but same functionalities with respect to big machines. The paper will show a real Electronic Control Unit (ECU) design of a machine controller, controlling both engine working point, transmission, and other utilities like PTO, 4WD, brakes and Differential Lock; the ECU was designed in accordance to ISO 25119 regulation, to meet AgPL = C or even D for some functionalities. The unit is a fully redundant electronic control unit with two CAN networks and some special safe state oriented mechanism, that allow the Performance Level C with less software analysis requirements compared with traditional solutions. All safety critical sensors are redounded and singularly diagnosable, all command effects are directly observable and most of commands are directly diagnosable.

Modern aircraft systems employ numerous processors to achieve system functionality. In particular, engine controls and power distribution subsystems rely heavily on software to provide safety-critical functionality, and are expected to move toward multicore architectures. The computing hardware-layer of avionic systems must be able to execute many concurrent workloads under tight deterministic execution guarantees to meet the safety standards. Single-chip multicores are attractive for safety-critical embedded systems due to their lightweight form factor. However, multicores aggressively share hardware resources, leading to interference that in turn creates non-deterministic execution for multiple concurrent workloads. We propose an approach to remove on-chip interference via a set of methods to spatio-temporally partition shared multicore resources.

Development of any safety critical software applications such as in the aerospace industry needs to comply to specific standards (DO-178) to meet airworthiness requirements. This standard is applicable to all airborne software. As such, the software development needs to perform certain verification activities to comply to the standard objectives. One of the verification activities is source code inspection or review to check that the implementation meets the specification captured in the form of requirements and other aspects such as coding style guidelines and documentation, such as, indentation used in code, sufficient comments or notes in the code files etc. Generally, this activity is carried out manually, supplemented by tools which are deployed to check errors and standards in the code by means of static analysis and practices such as test-driven development (TDD), wherein, the testing and analysis is done prior to the reviews.

In the paper at hand a model-based development approach for a diagnostic system for a multifunctional fuel cell system architecture will be presented. The approach consists primarily of four parts. The first part is a description of general steps needed to build an accurate component-based model of the system using a state of the art model-based diagnostic reasoning tool. As a first result there will be a static simulation model for nominal system behavior. The second part of the approach deals with the identification of safety critical failure conditions (SCFC) at a system level, e.g. low Power. The SCFCs are then mapped into the model. This means that categorized physical quantities and monitoring executives are chosen, that are appropriate for representing the specific SCFCs, e.g. low voltage at outlet of DC-DC converter module. According to step two there will be conflicts, meaning discrepancies between the simulated nominal and the mapped behavior.

During the last years there has been an explosion of functionality embedded within automotive vehicles, leading to a dramatic increase in the number of in vehicle ECUs. The transition from a federated to an integrated architecture would provide multiple economic benefits such as the reduction in the number of ECUs and wiring. However, software code is not composable by itself and it is difficult to proof the time and value correctness of safety-critical and non-safety-critical applications running within the same execution unit. In addition to this, the x-by-wire systems deployment will soon push the automotive industry in the area of safety-critical systems. This paper describes the “Time-Triggered Modelware” (TTM) novel approach for the design, development and execution of safety-critical embedded-systems that is based on a composable, efficient and deterministic (time and value domain correctness) execution environment.