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Viewing 121 to 150 of 21647
2015-04-14
Journal Article
2015-01-1584
Daniel E. Williams
Abstract The classic two-degree-of-freedom yaw-plane or “bicycle” vehicle model is augmented with two additional states to describe lane-keeping behavior, and further augmented with an additional control input to steer the rear axle. A simple driver model is hypothesized where the driver closes a loop on a projected lateral lane position. A rear axle steer control law is found to be a function of front axle steering input and vehicle speed that exhibits high speed stability and improved low speed maneuverability. The theoretically derived control law bears similarity to practical embodiments allowing a deeper understanding of the functional value of steering a rear axle.
2015-04-14
Journal Article
2015-01-1595
Kristoffer Lundahl, Chih Feng Lee, Erik Frisk, Lars Nielsen
Abstract Rollover has for long been a major safety concern for trucks, and will be even more so as automated driving is envisaged to becoming a key element of future mobility. A natural way to address rollover is to extend the capabilities of current active-safety systems with a system that intervenes by steering or braking actuation when there is a risk of rollover. Assessing and predicting the rollover is usually performed using rollover indices calculated either from lateral acceleration or lateral load transfer. Since these indices are evaluated based on different physical observations it is not obvious how they can be compared or how well they reflect rollover events in different situations. In this paper we investigate the implication of the above mentioned rollover indices in different critical maneuvers for a heavy 8×4 twin-steer truck.
2015-04-14
Journal Article
2015-01-1564
Joshua L. Every, Dennis A. Guenther, Gary J. Heydinger
Abstract Typically, when one thinks of advanced driver assistance systems (ADAS), systems such as Forward Collision Warning (FCW) and Collision Imminent Braking (CIB) come to mind. In these systems driver assistance is provided based on knowledge about the subject vehicle and surrounding objects. A new class of these systems is being implemented. These systems not only use information on the surrounding objects but also use information on the driver's response to an event, to determine if intervention is necessary. As a result of this trend, an advanced level of understanding of driver braking behavior is necessary. This paper presents an alternate method of analyzing driver braking behavior. This method uses a frequency content based approach to study driver braking and allows for the extraction of significantly more data from driver profiles than traditionally would have been done.
2015-04-14
Technical Paper
2015-01-1484
Daniel E. Toomey, Eric S. Winkel, Ram Krishnaswami
Abstract Since their inception, the design of airbag sensing systems has continued to evolve. The evolution of air bag sensing system design has been rapid. Electromechanical sensors used in earlier front air bag applications have been replaced by multi-point electronic sensors used to discriminate collision mechanics for potential air bag deployment in front, side and rollover accidents. In addition to multipoint electronic sensors, advanced air bag systems incorporate a variety of state sensors such as seat belt use status, seat track location, and occupant size classification that are taken into consideration by air bag system algorithms and occupant protection deployment strategies. Electronic sensing systems have allowed for the advent of event data recorders (EDRs), which over the past decade, have provided increasingly more information related to air bag deployment events in the field.
2015-04-14
Technical Paper
2015-01-0926
Tianyun Li, Min Xu, David Hung, Shengqi Wu, Siqi Cheng
Abstract Comparing with port-fuel-injection (PFI) engine, the fuel sprays in spark-ignition direct-injection (SIDI) engines play more important roles since they significantly influence the combustion stability, engine efficiency as well as emission formations. In order to design higher efficiency and cleaner engines, further research is needed to understand and optimize the fuel spray atomization and vaporization. This paper investigates the atomization and evaporation of n-pentane, gasoline and surrogate fuels sprays under realistic SIDI engine conditions. An optical diagnostic technique combining high-speed Mie scattering and Schlieren imaging has been applied to study the characteristics of liquid and vapor phases inside a constant volume chamber under various operating conditions. The effects of ambient temperature, fuel temperature, and fuel type on spray atomization and vaporization are analyzed by quantitative comparisons of spray characteristics.
2015-04-14
Technical Paper
2015-01-0938
Prashanth Karra, Thomas Rogers, Petros Lappas
Abstract The air entrainment process of a compressed natural gas transient fuel jet was investigated in a constant-volume chamber using Schlieren and particle image velocimetry (PIV) techniques. A new method of calculating air entrainment around a gaseous fuel jet is proposed using Schlieren and PIV imaging techniques. This method offers an alternative to calculation of an alternative to calculation of entrainment using LIF technique in gaseous fuel jets. Several Jet-ambient pressure ratios were tested. In each test, nitrogen was used to fill the chamber as an air surrogate before the jet of natural gas was injected. Schlieren high speed videography and PIV experiments were performed at the same conditions. Schlieren mask images were used to accurately identify the jet boundary which was then superimposed onto a PIV image. Vectors adjacent to the Schlieren mask in the PIV image were used to calculate the spatial distribution of the air entrainment at the jet boundary.
2015-04-14
Technical Paper
2015-01-0762
Mitsuru Kowada, Isao Azumagakito, Tetsuya Nagai, Nobuyuki Iwai, Ryoji Hiraoka
Abstract Attempts were made to measure knocking phenomenon by an optical method, which is free from influences of mechanical noises and is allowing an easy installation to an engine. Using a newly developed high durability optical probe, the light intensity of hydroxyl radical component, which is diffracted from the emitted light from combustion, was measured. The intensity of this emission component was measured at each crank angle and the maximum intensity in a cycle was identified. After that, the angular range in which the measured intensity exceeded 85% of this maximum intensity was defined as “CA85”. When a knocking was purposely induced by changing the conditions of the engine operation, there appeared the engine cycles that included CA85 less than a crank angle of 4 degrees. The frequency of occurrence of CA85 equal to or less than 4 degrees within a predetermined number of engine cycles, which can be interpreted as a knocking occurrence ratio, was denoted as “CA85-4”.
2015-04-14
Journal Article
2015-01-0811
Hiroki Tanaka, Kazunobu Kobayashi, Takahiro Sako, Yasuyuki Sakai, Masahiro Furutani, Kazunari Kuwahara
Abstract The ignition characteristics of each component of natural gas and the chemical kinetic factors determining those characteristics were investigated using detailed chemical kinetic calculations. Ethane (C2H6) showed a relatively short ignition delay time with high initial temperature; the heat release profile was slow in the early stage of the ignition process and rapid during the late stage. Furthermore, the ignition delay time of C2H6 showed very low dependence on O2 concentration. In the ignition process of C2H6, HO2 is generated effectively by several reaction paths, and H2O2 is generated from HO2 and accumulated with a higher concentration, which promotes the OH formation rate of H2O2 (+ M) = OH + OH (+ M). The ignition characteristics for C2H6 can be explained by H2O2 decomposition governing OH formation at any initial temperature.
2015-04-14
Journal Article
2015-01-0177
Thomas Fuhrman, Shige Wang, Marek Jersak, Kai Richter
Abstract Multi-core systems are promising a cost-effective solution for (1) advanced vehicle features requiring dramatically more software and hence an order of magnitude more processing power, (2) redundancy and mixed-IP, mixed-ASIL isolation required for ISO 26262 functional safety, and (3) integration of previously separate ECUs and evolving embedded software business models requiring separation of different software parts. In this context, designing, optimizing and verifying the mapping and scheduling of software functions onto multiple processing cores becomes key. This paper describes several multi-core task design and scheduling design options, including function-to-task mapping, task-to-core allocation (both static and dynamic), and associated scheduling policies such as rate-monotonic, criticality-aware priority assignment, period transformation, hierarchical partition scheduling, and dynamic global scheduling.
2015-04-14
Technical Paper
2015-01-0174
Advaita Datar, Amey Zare
Abstract Verification and Validation (V&V) techniques commonly use static analysis to detect property violations in modern software systems. However, besides checking for general programming errors like division by zero, array index out of bound etc., certain program patterns can also be verified in order to detect inconsistencies in the software. For instance, there could be several strongly related program entities, such as groups of variables or data structure members updated together, which are often observed across various parts of a program. We term such strongly related entities as group variables. When only a subset of group variables is updated at some part of a program, it could probably be a result of some inconsistency in implementation which may lead to unexpected behavior or failure of the underlying system. Therefore, verifying group variables and their write operations is essential to ensure the safety and reliability of software.
2015-04-14
Technical Paper
2015-01-0173
Stephen Barrett, Maximilien Bouchez
Abstract Engine ECU testing requires sophisticated sensor simulation and event capture equipment. FPGAs are the ideal devices to address these requirements. Their high performance and high flexibility are perfectly suited to the rapidly changing test needs of today's advanced ECUs. FPGAs offer significant advantages such as parallel processing, design scalability, ultra-fast pin-to-pin response time, design portability, and lifetime upgradability. All of these benefits are highly valuable when validating constantly bigger embedded software in shorter duration. This paper discusses the collaboration between Valeo and NI to define, implement, and deploy a graphical, open-source, FPGA-based engine simulation library for ECU verification.
2015-04-14
Technical Paper
2015-01-0191
Priti R. Ranadive, Vinay Vaidya, Chaitanya Rajguru
Abstract Improving reliability and quality of software is a major aspect in automotive industry. Software reliability and quality improves by reducing bugs or defects in the software. However, finding these defects at an early stage in the software development life cycle is important to reduce rework and cost. Manually detecting defects or bugs in large code sets is time consuming and is less accurate. Hence, using static or dynamic analysis tools has become a standard practice in automotive industry. Though many such tools are commercially available, it is observed that these tools are less used for various reasons. Some of the major reasons are users need to spend considerable amount of time to learn to use these tools to get desired output reports, customized checks are required for an application that are not provided by the tool and reports are too lengthy as well as cumbersome to analyze.
2015-04-14
Technical Paper
2015-01-0190
Mostafa Anwar Taie, Ibrahim El-Faramawy, Mohamed Elmawazini
Abstract In embedded system software architectural design, the Real-Time (RT) behavior estimation needs special care and contains many technical challenges. Most of the current approaches depend on either the engineering judgment or the actual measurements that are performed during the integration-testing phase. Both approaches may cause errors that lead to violations in the RT constraints. Both approaches are not error proof and can yield to RT constraints violations discovered during simulation of RT architectural design or during product validation. Impact on project could even be a Central Processing Unit (CPU) change. In this work, Operating System (OS) process Execution Time (ET) is considered the basic element of RT architectural design. Each process ET is predicted based on previous software releases, using Machine Learning (ML) algorithms.
2015-04-14
Journal Article
2015-01-0194
Hua Zeng, Isao Hoda, William Ivan, Andrew Baker, Syed Kadry, Hiroki Funato, Jia Li, Masayoshi Takahashi, Hideyuki Sakamoto, Ryuichi Saito
Abstract Electromagnetic compatibility (EMC) is becoming more important in power converters and motor drives as seen in hybrid electric vehicles (HEV) to achieve higher reliability of the vehicle and its components. Electromagnetic interference (EMI) of the electronic components for a vehicle are evaluated and validated at a component-level test bench; however, it is sometimes observed that the EMI level of the components can be changed in a vehicle-level test due to differences in the vehicle's configuration (cable routing, connecting location etc.). In this presentation, a vehicle-level EMC simulation methodology is introduced to estimate radiated emissions from a vehicle. The comparison between the simulation and measurement results is also presented and discussed.
2015-04-14
Technical Paper
2015-01-0192
Yukihide Niimi, Toshinori Matsui, Naoya Tsuchiya
Abstract Vehicle electronics systems will continue to become more complex and larger in scale. This causes their development to be conducted without control. As a result, system development involves things becoming intertwined with each other, like spaghetti. This has made it extremely difficult to develop an entire electronics system coherently and efficiently, from functional architecture down to physical architecture. There is thus a need to reform the development style of the electronics field to a style which will continuously and efficiently generate high-quality products. This will be achieved by dividing development into functions and components. Function development refer to developing functions that OEMs want to equip in the vehicles, that is, “what to make. Components development refers to “how to realize these components. For this activity, it is necessary to promote and accelerate platform-based development looking down at entire electronics systems.
2015-04-14
Technical Paper
2015-01-0195
Satishchandra C. Wani
Abstract Bond wires are used in automotive electronic modules to carry current from external harness to components where flexibility under thermal cyclic loading is very essential between PCB (Printed Circuit Board) and connectors. They are very thin wires (few μm) made up of gold, aluminum or copper and have to undergo mechanical reliability to withstand extreme mechanical and thermal loads during different vehicle operation scenarios. Thermal reliability of bond wire is to make sure that it can withstand prescribed electric current under given boundary conditions without fusing thereby retaining electronic module's functionality. While carrying current, bond wire by virtue of its nature resists electric current flow and generates heat also called as joule heating. Joule heating is proportional to current flow and electrical resistance and if not handled properly can lead to thermal run away conditions.
2015-04-14
Journal Article
2015-01-0198
Hironobu Akita, Nobuaki Matsudaira, Chao Chen, Takasuke Ito, Shigeki Ohtsuka
Abstract With the evolution of automotive features, larger flash program size has been required even at the local electronic control units (ECUs). As the flash programming data rate increases, Ethernet is adopted as a global data port from the external source. However, it can not be applied to the bus type network topology between the domain control unit (DCU) and the local ECUs, because it uses a peer-to-peer type network topology. On the other hand, high speed CAN-FD has been studied recently for this bus topology, but its data rate is limited at the range of several mega bps due to the signal waveform distortion caused by the multiple reflections at the non-terminated stubs. This paper describes a novel distortion cancelling for the bus topology as the pre-emphasis technique, in which the digital signal processing (DSP) compensates the complicated signal distortion caused by the multiple reflections.
2015-04-14
Journal Article
2015-01-0179
Ralph Mader, Armin Graf, Gerd Winkler
Abstract The combustion engine will be the dominant drive for motor vehicles despite all the advances in the electrification of the drive train, for many years. The greater are the challenges for the automotive industry, especially in fuel consumption (CO2) and the environmental impacts of other emissions. From the fuel supply to the engine, up to the exhaust after treatment, new or improved functions are needed, which are integrated into increasingly powerful control electronics. This modern electronic engine management and powertrain controller will remain key components in the vehicle. As most of the micro controllers for future applications will be MultiCores, this paper gives an overview on how PowerSAR® supports this kind of architectures. It shows the concepts applied in the basic software area as well as for the applicative software. Further it will show the impact on the development process as well as the integration support for software delivered by the OEM.
2015-04-14
Journal Article
2015-01-0197
Jan Seyler, Nicolas Navet, Loïc Fejoz
Abstract Scalable Service-Oriented Middleware on IP (SOME/IP) is a proposal aimed at providing service-oriented communication in vehicles. SOME/IP nodes are able to dynamically discover and subscribe to available services through the SOME/IP Service Discovery protocol (SOME/IP SD). In this context, a key performance criterion to achieve the required responsiveness is the subscription latency that is the time it takes for a client to subscribe to a service. In this paper we provide a recap of SOME/SD and list a number of assumptions based on what we can foresee about the use of SOME/IP in the automotive domain. Then, we identify the factors having an effect on the subscription latency, and, by sensitivity analysis, quantify their importance regarding the worst-case service subscription latency. The analysis and experiments in this study provide practical insights into how to best configure SOME/IP SD protocol.
2015-04-14
Journal Article
2015-01-0183
Georg Macher, Muesluem Atas, Eric Armengaud, Christian Kreiner
Abstract Automotive embedded systems have become very complex, are strongly integrated, and the safety-criticality and real-time constraints of these systems raise new challenges. The OSEK/VDX standard provides an open-ended architecture for distributed real-time capable units in vehicles. This is supported by the OSEK Implementation Language (OIL), a language aiming at specifying the configuration of these real-time operating systems. The challenge, however, is to ensure consistency of the concept constraints and configurations along the entire product development. The contribution of this paper is to bridge the existing gap between model-driven systems engineering and software engineering for automotive real-time operating systems (RTOS). For this purpose a bidirectional tool bridge has been established based on OSEK OIL exchange format files.
2015-04-14
Technical Paper
2015-01-0180
Karsten Schmidt, Denny Marx, Kai Richter, Konrad Reif, Andreas Schulze, Torsten Flämig
Abstract With the increasing complexity of electronic vehicle systems, one particular “gap” between function development and ECU integration becomes more and more apparent, and critical; albeit not new. The core of the problem is: as more functions are integrated and share the same E/E resources, they increasingly mutually influence and disturb each other in terms of memory, peripherals, and also timing and performance. This has two consequences: The amount of timing-related errors increases (because of the disturbance) and it becomes more difficult to find root causes of timing errors (because of the mutual influences). This calls for more systematic methods to deal with timing requirements in general and their transformation from function timing requirements to software architecture timing requirements in particular.
2015-04-14
Technical Paper
2015-01-0184
James Price
Abstract More than ten years have passed since the establishment of the AUTOSAR consortium. Today, AUTOSAR has become a well-established standard for automotive electronic control unit (ECU) development and network design. In fact, several original equipment manufacturers (OEMs) now mandate AUTOSAR when sourcing ECUs. With that being said, the standard is getting more complex as new concepts are added with each new release, making integration an increasingly difficult challenge - let alone a challenge developing it alongside ECU application functionality. This paper addresses the integration of AUTOSAR 4.x basic software stack into an ECU project and offers proposed flows for the integration process starting from the ECU extract to a fully configured AUTOSAR stack.
2015-04-14
Technical Paper
2015-01-0189
Rolf Schneider, Dominik Juergens, Andre Kohn
Abstract In the context of the ARAMiS project, AUDI AG contributed the development of a multi-core demonstrator based on car functions already in production. For this demonstrator, these legacy car functions were ported from single-core platforms to a multi-core platform to gain real world close-to-production experience while utilizing the new technology. For complex functions with high demands for computational resources, it may be necessary to distribute computation over several cores. In this context, we investigated the parallelization of a legacy sequential AUTOSAR function. A main contribution of this work is an analysis of mechanisms provided by AUTOSAR, their limitations and, possible remedy. This paper will point out observations and experiences during the development of this demonstrator and show practical solutions for parallelization in an AUTOSAR environment.
2015-04-14
Technical Paper
2015-01-0186
Syed Arshad Kazmi, Jin Seo Park, Jens Harnisch
Abstract End of Line tests are brief set of tests intended to evaluate ECU's in order to ensure correct functioning of its intended functionality. As these tests are executed on the production line, available time to perform these tests is limited. On one hand, faster production demands require these tests and its framework to be designed in a time optimized manner. On the other hand, increase in ECU functionality translates to an increase in test's functional coverage, requiring more time. Therefore the time taken to execute the tests reaches a critical point in overall ECU production. Availability of multicore microcontrollers with increase in clock speed can increase the performance of end of line tests, but design challenges e.g. synchronization do not guarantee a linear performance increase. Therefore, design of test execution framework is absolutely critical to increase performance of test execution.
2015-04-14
Journal Article
2015-01-0208
Hongtao Yu, Reza Langari
Abstract This paper presents a model-based approach to detect unintended acceleration (UA) as well as other vehicle problems. A diagnostic system is formulated by detecting several specific vehicle events such as acceleration peaks and gear shifting. Mathematical models are created for these events based on simulation data and the final diagnostic conclusion is drawn from the voting result of all these models. The detection algorithm is validated using independent data sets obtained from Matlab/Simulink. A three dimensional vehicle model is built to implement traffic simulation. Vehicle problems and drivers' reactions are simulated and added during the process. Sensor noise is also considered and corresponding filters are designed and applied. The results show that the fault diagnostic system is successful in detecting UA.
2015-04-14
Technical Paper
2015-01-0213
Vinuchackravarthy Senthamilarasu, Anusha Baskaran, Krishnan Kutty
Abstract In the research field of automotive systems, Advanced Driver Assistance Systems (ADAS) are gaining paramount importance. As the significance for such systems increase, the challenges associated with it also increases. These challenges can arise due to technology, human factors, or due to natural elements (haze, fog, rain etc.). Among these, natural challenges, especially haze, pose a major setback for technologies depending on vision sensors. It is a known fact that the presence of haze in the atmosphere degrades the driver's visibility as well as the information available with the vision based ADAS. To ensure reliability of ADAS in different climatic conditions, it is vital to get back the information of the scene degraded by haze prior to analyzing the images. In this paper, the proposed work addresses this challenge with a novel and faster image preprocessing technique that can enhances the quality of haze affected images both in terms of visibility and visual perception.
2015-04-14
Technical Paper
2015-01-0215
Reena Kumari Behera, Smita Nair, Vinay Vaidya
Abstract This paper presents a simple yet novel approach to remove redundant data from outdoor scenes, thus finding significant application in Advanced Driver Assistance Systems (ADAS). A captured outdoor scene has two main parts, the ground region consisting of the road area along with other lane markings and the background region consisting of various structures, trees, sky etc. To extract the ground region, first the yellow and white road markings are segmented based on the HSI (Hue Saturation Intensity) color model and these regions are filled with the surrounding road color. Further the background region is segmented based on the Lab (Color-opponent) color model, which shows significant improvement as compared to other color spaces. To extract the background region such as the sky or ground region, it is assumed that the top and bottom most portions of the image does not consist of useful information.
2015-04-14
Technical Paper
2015-01-0199
Stefan Fuchs, Hans-Peter Schmidt
Abstract Real time data transfer over Ethernet, with an inhomogeneous physical layer is studied. Within the Ethernet network 100Base-TX and BroadR Reach© physical layers are used. Synchronization of devices via Ethernet is investigated and synchronized transfer of video streams is shown. Purpose-built Ethernet-Physical Layer Adapters (E-PLAs) are applied. It is demonstrated that an Ethernet network with different physical layers may be used for real time data transfer with just a little trade-off in synchronization and transfer delay.
2015-04-14
Technical Paper
2015-01-0216
Ping-Min Hsu, Ming Hung Li, Kuo-Ching Chang
Abstract This paper discusses noise filtering in an autonomous emergency braking (AEB) system with a sensor fusion between a millimeter wave (MMW) radar and a camera. Three kinds of noise, namely twice harmonic noise, ground noise, and specular reflection noise, are then filtered. The former is caused by the reflection of a radar wave between a target object and the MMW radar; therefore, one of the sensing distances would be twice as longer as one of others. An object featuring this characteristic is treated as the noise and filtered. Next, detecting a ground metal as the target object generates the second noise with a focus of car-like objects. That is, an object-with the sensing distance from the MMW radar being smaller than that from the camera by a threshold value-is taken as the ground metal noise and ignored. Moreover, the third noise happens when there is a radar wave reflection between an object and its surroundings.
2015-04-14
Journal Article
2015-01-0200
Karsten Schmidt, Udo Dannebaum, Harald Zweck
Abstract In-vehicle communication faces increasing bandwidth demands, which can no longer be met by today's MOST150, FlexRay or CAN networks. In recent years, Fast Ethernet has gained a lot of momentum in the automotive world, because it promises to bridge the bandwidth gap. A first step in this direction is the introduction of Ethernet as an On Board Diagnostic (OBD) interface for production vehicles. The next potential use cases include the use of Ethernet in Driver Assistance Systems and in the infotainment domain. However, for many of these use cases, the Fast Ethernet solution is too slow to move the huge amount of data between the Domain Controllers, ADAS Systems, Safety Computer and Chassis Controller in an adequate way. The result is the urgent need for a network technology beyond the Fast Ethernet solution. The question is: which innovation will provide enough bandwidth for domain controllers, fast flashing routines, video data, MOST-replacement and internal ECU buses?
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