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Viewing 211 to 240 of 16441
2017-03-28
Technical Paper
2017-01-0013
Gaurav Gupta, Ujjwal Modi
Abstract Flickering problems in automotive vehicles have been observed from long time. After assessing numerous vehicles it was observed that whenever the hazard lights in a vehicle are activated, it leads to flickering problems in lights/small electrical components. This paper is to provide the solution for flickering snags in electrical components in a vehicle. The lights that are analyzed to be flickering/wavering are generally small loads such as LEDs in the bus roof area, small parking lamps, LEDs used in instrument clusters, cabin lamps, etc. The flickering in lights can turn out to be very unappealing at certain times. This absurd behavior can lead to extreme discomfort to the passengers and can also be a source of major distraction to the driver. This study presents the design & development for a vehicle platform & implementation that assesses the problem. Because of abrupt behavior of flasher circuits, voltage surges are observed, leading to flickering problems.
2017-03-28
Technical Paper
2017-01-1616
Scott A. Rush
Abstract Modern automotive manufacturing and after-sale service environments require tailoring of configuration values or “calibrations” within the vehicle’s various electronic control units (ECUs) to that vehicle’s specific option content. Historically, ECU hardware and software limitations have led designers to implement calibratable values using opaque binary blocks tied directly to ECU internal software data structures. Such coupling between calibration data files and ECU software limits traceability and reuse across different software versions and ECU variants. However, more and more automotive ECUs are featuring fast microprocessors, large memories, and preemptive, multi-tasking operating systems that open opportunities to object-oriented approaches. This paper presents the CalDef system for automotive ECU calibration software architecture.
2017-03-28
Technical Paper
2017-01-0042
David Andrade, Rodrigo Adamshuk, William Omoto, Felipe Franco, João Henrique Neme, Sergio Okida, Angelo Tusset, Rodrigo Amaral, Artur Ventura, Max Mauro Dias Santos
Abstract The continuous growth of market for Advanced Driver Assistance Systems based on image processing features leads to the advance of the applied techniques, increasing thus the driving safety. Mostly of the edge detection algorithms are traditional approaches, and to achieve improvements it is necessary to combine different methods. The purpose of this work is to implement a strategy for road lanes detection using the traditional Canny operator. Oriented filters are used to remove unnecessary information and vehicle’s yaw rate signal is used to adaptively correct the filter orientation according to the lane boundaries directions. In sequence, morphological filters using dilation and analysis of connected components are applied in order to remove the noise components of the edge detection stage.
2017-03-28
Technical Paper
2017-01-0037
Xianyao Ping, Gangfeng Tan, Yahui Wu, Binyu Mei, Yuxin Pang
Abstract The drivers' hysteretic perception to surrounding environment will affect vehicular fuel economy, especially for the heavy-duty vehicles driving under complex conditions and long distance in mountainous areas. Unreasonable acceleration or deceleration on the slope will increase the fuel consumption. Improving the performance of the engine and the transmission system has limited energy saving potential, and most fuel-efficient driving assistant systems don't consider the road conditions. The main purpose of this research is to introduce an economic driving scheme with consideration of the prestored slope information in which the vehicle speed in mountainous slopes is reasonably planned to guide the driver's behavior for reduction of the fuel consumption. Economic driving optimization algorithm with low space dimension and fast computation speed is established to plan accurate and real-time economic driving scheme.
2017-03-28
Technical Paper
2017-01-1654
Arun Ganesan, Jayanthi Rao, Kang Shin
Abstract Modern vehicles house many advanced components; sensors and Electronic Control Units (ECUs) — now numbering in the 100s. These components provide various advanced safety, comfort and infotainment features, but they also introduce additional attack vectors for malicious entities. Attackers can compromise one or more of these sensors and flood the vehicle’s internal network with fake sensor values. Falsified sensor values can confuse the driver, and even cause the vehicle to misbehave. Redundancy can be used to address compromised sensors, but adding redundant sensors will increase the cost per vehicle and is therefore less attractive. To balance the need for security and cost-efficiency, we exploit the natural redundancy found in vehicles. Natural redundancy occurs when the same physical phenomenon causes symptoms in multiple sensors. For instance, pressing the accelerator pedal will cause the engine to pump faster and increase the speed of the vehicle.
2017-03-28
Technical Paper
2017-01-1657
Jesse Edwards, Ameer Kashani
Abstract In the past few years, automotive electronic control units (ECUs) have been the focus of many studies regarding the ability to affect the deterministic operation of safety critical cyber-physical systems. Researchers have been able to successfully demonstrate flaws in security design that have considerable, dramatic impacts on the functional safety of a target vehicle. With the rapid increase in data connectivity within a modern automobile, the attack surface has been greatly broadened to allow adversaries remote access to vehicle control system software and networks. This has serious implications, as a vast number of vulnerability disclosures released by security researchers point directly to common programming bugs and software quality issues as the root cause of successful exploits which can compromise the vehicle as a whole. In this paper, we aim to bring to light the most prominent categories of bugs found during the software development life cycle of an automotive ECU.
2017-03-28
Technical Paper
2017-01-1612
Tri P. Doan, Subramaniam Ganesan
Abstract Robert Bosch GmBH proposed in 2012 a new version of communication protocol named as Controller area network with Flexible Data-Rate (CANFD), that supports data frames up to 64 bytes compared to 8 bytes of CAN. With limited data frame size of CAN message, and it is impossible to be encrypted and secured. With this new feature of CAN FD, we propose a hardware design - CAN crypto FPGA chip to secure data transmitted through CAN FD bus by using AES-128 and SHA-1 algorithms with a symmetric key. AES-128 algorithm will provide confidentiality of CAN message and SHA-1 algorithm with a symmetric key (HMAC) will provide integrity and authentication of CAN message. The design has been modeled and verified by using Verilog HDL – a hardware description language, and implemented successfully into Xilinx FPGA chip by using simulation tool ISE (Xilinx).
2017-03-28
Journal Article
2017-01-1179
Tatsuya Arai, Ozaki Takashi, Kazuki Amemiya, Tsuyoshi Takahashi
Abstract Polymer electrolyte membrane fuel cell (PEFC) systems for fuel cell vehicles (FCVs) require both performance and durability. Carbon is the typical support material used for PEFC catalysts. However, hydrogen starvation at the anode causes high electrode potential states (e.g., 1.3 V with respect to the reversible hydrogen electrode) that result in severe carbon support corrosion. Serious damage to the carbon support due to hydrogen starvation can lead to irreversible performance loss in PEFC systems. To avoid such high electrode potentials, FCV PEFC systems often utilize cell voltage monitor systems (CVMs) that are expensive to use and install. Simplifying PEFC systems by removing these CVMs would help reduce costs, which is a vital part of popularizing FCVs. However, one precondition for removing CVMs is the adoption of a durable support material to replace carbon.
2017-03-28
Journal Article
2017-01-1170
Tong Zhang, Chen Wang, Wentai Zhou, Huijun Cheng, Haisheng Yu
Abstract Because a compound power-split transmission is directly connected to the engine, dramatic fluctuations in engine output torque result in strong jerks and torque losses when the hybrid vehicle is in mode transition from electric drive mode to hybrid drive mode. In order to enhance ride comfort and reduce the output torque gap during mode transition process, a brake clutch assisted coordinated control strategy was developed. Firstly, the dynamic plant model of the power-split vehicle including driveline model, engine ripple torque and brake clutch torque was deduced. Secondly, the brake clutch assisted mode transition process was analyzed, and the output torque capability was compared between cases of both brake clutch assisted and unassisted mode transition process. Thirdly, a coordinated control strategy was designed to determine the desired motor torque, brake clutch torque, engine torque, and the moment of fuel injection.
2017-03-28
Journal Article
2017-01-1184
Kiyoshi Handa, Shigehiro Yamaguchi, Kazuya Minowa, Steven Mathison
Abstract A new hydrogen fueling protocol named MC Formula Moto was developed for fuel cell motorcycles (FCM) with a smaller hydrogen storage capacity than those of light duty FC vehicles (FCV) currently covered in the SAE J2601 standard (over than 2kg storage). Building on the MC Formula based protocol from the 2016 SAE J2601 standard, numerous new techniques were developed and tested to accommodate the smaller storage capacity: an initial pressure estimation using the connection pulse, a fueling time counter which begins the main fueling time prior to the connection pulse, a pressure ramp rate fallback control, and other techniques. The MC Formula Moto fueling protocol has the potential to be implemented at current hydrogen stations intended for fueling of FCVs using protocols such as SAE J2601. This will allow FCMs to use the existing and rapidly growing hydrogen infrastructure, precluding the need for exclusive dispensers or stations.
2017-03-28
Journal Article
2017-01-1182
Xin Guo, Xu Peng, Sichuan Xu
Abstract Startup from subzero temperature is one of the major challenges for polymer electrolyte membrane fuel cell (PEMFC) to realize commercialization. Below the freezing point (0°C), water will freeze easily, which blocks the reactant gases into the reaction sites, thus leading to the start failure and material degradation. Therefore, for PEMFC in vehicle application, finding suitable ways to reach successful startup from subfreezing environment is a prerequisite. As it’s difficult and complex for experimental studies to measure the internal quantities, mathematical models are the effective ways to study the detailed transport process and physical phenomenon, which make it possible to achieve detailed prediction of the inner life of the cell. However, review papers only on cold start numerical models are not available. In this study, an extensive review on cold start models is summarized featuring the states and phase changes of water, heat and mass transfer.
2017-03-28
Journal Article
2017-01-1183
Kenneth Johnson, Michael J. Veenstra, David Gotthold, Kevin Simmons, Kyle Alvine, Bert Hobein, Daniel Houston, Norman Newhouse, Brian Yeggy, Alex Vaipan, Thomas Steinhausler, Anand Rau
Abstract Fuel cell vehicles are entering the automotive market with significant potential benefits to reduce harmful greenhouse emissions, facilitate energy security, and increase vehicle efficiency while providing customer expected driving range and fill times when compared to conventional vehicles. One of the challenges for successful commercialization of fuel cell vehicles is transitioning the on-board fuel system from liquid gasoline to compressed hydrogen gas. Storing high pressurized hydrogen requires a specialized structural pressure vessel, significantly different in function, size, and construction from a gasoline container. In comparison to a gasoline tank at near ambient pressures, OEMs have aligned to a nominal working pressure of 700 bar for hydrogen tanks in order to achieve the customer expected driving range of 300 miles.
2017-03-28
Journal Article
2017-01-1201
Zhenli Zhang, Zhihong Jin, Perry Wyatt
Abstract Lithium plating is an important failure factor for lithium ion battery with carbon-based anodes and therefore preventing lithium plating has been a critical consideration in designs of lithium ion battery and battery management system. The challenges are: How to determine the charging current limits which may vary with temperature, state of charge, state of health, and battery operations? Where are the optimization rooms in battery design and management system without raising plating risks? Due to the complex nature of lithium plating dynamics it is hard to detect and measure the plating by any of experimental means. In this work we developed an electrochemical model that explicitly includes lithium plating reaction. It enables both determination of plating onset and quantification of plated lithium. We have studied the effects of charging pulses on homogenous plating in order to provide guidance for lithium ion battery design in hybrid applications.
2017-03-28
Journal Article
2017-01-1213
Yilin Yin, Zhong Zheng, Song-Yul Choe
Abstract Analysis of thermal behavior of Lithium ion battery is one of crucial issues to ensure a safe and durable operation. Temperature is the physical quantity that is widely used for analysis, but limited for accurate investigations of behavior of heat generation of battery because of sensitivities affected by heat transfer in experiments. Calorimeter available commercially is widely used to measure the heat generation of battery, but does not follow required dynamics because of a relatively large thermal time constant given by cavity and a limited heat transfer capability. In this paper, we proposed a highly dynamic calorimeter that was constructed using two thermoelectric devices (TEMs). For the design of the calorimeter and its calibration, a printed circuit board (PCB) with the same size as the battery was used as a dummy load to generate controlled heat.
2017-03-28
Journal Article
2017-01-1193
Yongcai Wang, Rajaram Subramanian, Sarav Paramasivam, George Garfinkel
Abstract Mechanical shock tests for lithium metal and lithium-ion batteries often require that each cell or battery pack be subjected to multiple shocks in the positive and negative directions, of three mutually perpendicular orientations. This paper focuses on the no-disassembly requirement of those testing conditions and on the CAE methodology specifically developed to perform this assessment. Ford Motor Company developed a CAE analysis method to simulate this type of test and assess the possibility of cell dislodging. This CAE method helps identify and diagnose potential failure modes, thus guiding the Design Team in developing a strategy to meet the required performance under shock test loads. The final CAE-driven design focuses on the structural requirement and optimization, and leads to cost savings without compromising cell or pack mechanical performance.
2017-03-28
Journal Article
2017-01-1198
Po Hong, Hongliang Jiang, Jian qiu Li, Liangfei Xu, Minggao Ouyang
Abstract The lithium-ion battery plays an important role in saving energy and lowering emissions. Many parameters like temperature have an influence on the characteristic of the battery and this phenomenon becomes more serious in an electric vehicle. In this paper, the application of a boost DC/DC converter to the battery system of high power for online AC impedance identification is proposed. The function of the converter is to inject a current excitation signal into the battery at work and the normal output current is drawn by a load. Through analyzing the average state space equations and deriving the small signal model of the converter, the gain function is deduced of the fluctuated current signal against the fluctuated duty cycle which controls the converter. The control algorithm is designed and the system model is verified using Matlab/Simulink with respect to the disturbance current signal generation, the gain function and its variation with frequency range.
2017-03-28
Journal Article
2017-01-1218
XINCHEN ZHAO, Yalan Bi, Song-Yul Choe
Abstract We propose a reduced order model (ROM) for LFP/graphite cells derived from the electrochemical thermal principles that considers degradation effects and validated against experimental data obtained from a large format pouch type LFP/graphite cell whose nominal capacity is 20Ah. The characteristics of the two-phase transition and path dependence were taken into account in the ROM using a shrinking-core model with a moving interface that presents lithium rich and deficient phase. Different currents (0.1/1/3/4C) were applied to fresh cells at different ambient temperatures (25/35/45°C). Comparison between simulated results of the ROM and the collected experimental data shows a good match. The path dependence was also analyzed experimentally. For degradation model, side reaction is treated as the predominant cause of degradation of cells, which are affected by the operating conditions, such as temperature and SOC cycling range.
2017-03-28
Journal Article
2017-01-1216
Edward C. Fontana, Rick Barnett, Robert Catalano, James Harvey, Jiacheng He, George Ottinger, John Steel
Abstract Electric cars can help cities solve air quality problems, but drivers who live in apartments have no convenient way to charge daily, absent the well-controlled private garages where most electric vehicles (EVs) are currently charged each night. Environmentally robust, hands-free, inductive chargers would be ideal, but energy efficiency suffers. We asked whether the precise parking alignment provided by self-driving cars could be used to provide convenient inductive charging with improved charging efficiencies. To answer this question, we split an inductor-inductor-capacitor (LLC) battery charger at the middle of the isolation transformer. The power factor correction, tank elements, and transformer primary windings are stationary, while the transformer secondary, rectifiers, and battery control logic are on the vehicle. The transformer is assembled each time the EV parks.
2017-03-28
Journal Article
2017-01-1244
Keisuke Kimura, Tasbir Rahman, Tadashi Misumi, Takeshi Fukami, Masafumi Hara, Sachiko Kawaji, Satoru Machida
Abstract One way to improve the fuel efficiency of HVs is to reduce the losses and size of the Power Control Unit (PCU). To achieve this, it is important to reduce the losses of power devices (such as IGBTs and FWDs) used in the PCU since their losses account for about 20% of the total loss of an HV. Furthermore, another issue when reducing the size of power devices is ensuring the thermal feasibility of the downsized devices. To achieve the objectives of the 4th generation PCU, the following development targets were set for the IGBTs: reduce power losses by 19.8% and size by 30% compared to the 3rd generation. Power losses were reduced by the development of a new Super Body Layer (SBL) structure, which improved the trade-off relationship between switching and steady-state loss. This trade-off relationship was improved by optimizing the key SBL concentration parameter.
2017-03-28
Journal Article
2017-01-1243
Yan Zhou, Lihua Chen, Shuitao Yang, Fan Xu, Mohammed Khorshed Alam
Abstract The IGBTs are dominantly used in traction inverters for automotive applications. Because the Si-based device technology is being pushed to its theoretical performance limit in such applications during recent years, the gate driver design is playing a more prominent role to further improve the traction inverter loss performance. The conventional gate driver design in traction inverter application needs to consider worst case scenarios which adversely limit the semiconductor devices' switching speed in its most frequent operation regions. Specifically, when selecting the gate resistors, the IGBT peak surge voltage induced by fast di/dt and stray inductance must be limited below the device rated voltage rating under any conditions. The worst cases considered include both highest dc bus voltage and maximum load current. However, the traction inverter operates mainly in low current regions and at bus voltage much lower than the worst case voltage.
2017-03-28
Technical Paper
2017-01-1437
William Bortles, Sean McDonough, Connor Smith, Michael Stogsdill
Abstract The data obtained from event data recorders found in airbag control modules, powertrain control modules and rollover sensors in passenger vehicles has been validated and used to reconstruct crashes for years. Recently, a third-party system has been introduced that allows crash investigators and reconstructionists to access, preserve and analyze data from infotainment and telematics systems found in passenger vehicles. The infotainment and telematics systems in select vehicles retain information and event data from cellular telephones and other devices connected to the vehicle, vehicle events and navigation data in the form of tracklogs. These tracklogs provide a time history of a vehicle’s geolocation that may be useful in investigating an incident involving an automobile or reconstructing a crash. This paper presents an introduction to the type of data that may be retained and the methods for performing data acquisitions.
2017-03-28
Technical Paper
2017-01-0238
Velappan Shalini, Sridharan Krishnamurthy, Srinivasan Narasimhan
Abstract This study compares the model efficacy of Neural Network and Vector Auto Regression. Further it also analyses the impact of predictors controlling for total industry volume. Understanding both the methodologies has their distinctive advantages and disadvantages. Our empirical findings indicate that based on the characteristics of data such as non-stationary, non-linearity and non-normality paves the way for use of machine learning algorithm relative to econometrics technique. Our results suggest that data type and its characteristics are more important in determining the methodology than the methodology itself. In industry, econometrics methodologies are widely used due to their usage simplicity and its ability to explain the relationships in simple terms.
2017-03-28
Technical Paper
2017-01-0059
Barbaros Serter, Christian Beul, Manuela Lang, Wiebke Schmidt
Abstract Today, highly automated driving is paving the road for full autonomy. Highly automated vehicles can monitor the environment and make decisions more accurately and faster than humans to create safer driving conditions while ultimately achieving full automation to relieve the driver completely from participating in driving. As much as this transition from advanced driving assistance systems to fully automated driving will create frontiers for re-designing the in-vehicle experience for customers, it will continue to pose significant challenges for the industry as it did in the past and does so today. As we transfer more responsibility, functionality and control from human to machine, technologies become more complex, less transparent and making constant safe-guarding a challenge. With automation, potential misuse and insufficient system safety design are important factors that can cause fatal accidents, such as in TESLA autopilot incident.
2017-03-28
Technical Paper
2017-01-0053
Wolfgang Granig, Friedrich Rasbornig, Dirk Hammerschmidt, Mario Motz, Thomas Zettler, Michael Strasser, Alessandro Michelutti
Abstract Functional safe systems fulfilling the ISO 26262 standard are getting more important for automotive applications where additional redundant and diverse functionality is needed for higher rated ASIL levels. This can result in a very complex and expensive system setup. Here we present a sensor product developed according ISO 26262. This sensor product comprises a two channel redundant and also diverse implemented magnetic field sensor concept with linear digital outputs on one monolithically integrated silicon substrate. This sensor is used for ASIL D applications like power-steering torque measurement, where the torque is transferred into a magnetic field signal in a certain magnetic setup, but can also be used in other demanding sensor applications concerning safety. This proposed and also implemented solution is beneficial because of implementation on a single chip in one single chip-package but anyway fulfilling ASIL D requirements on system level.
2017-03-28
Technical Paper
2017-01-1212
Hong Jia Hong, Jesus Ruiz Sevillano, Clemens Kain, Guenter Hofer, Karl Felber, Wai Keung Chan
Abstract The automotive industry is moving from fossil carburant to electric drive trains due to the stringent CO2 reduction policies. In this context, the electric energy storage becomes one of the key parameters of successful rolling out electrified vehicles. Typical battery management systems comprises of battery cells measurement and monitoring, balancing function, temperature monitoring, together with the State of Charge and State of Health estimations based on the given measurements. Together with the functions above, a robust internal IC communication protocol is one of the key parameters to guarantee battery performance as well as safety. This paper focuses on the automotive battery communication system. On one side, the importance of the communication system and its impact in the EDT (electric drive train) is discussed including safety aspects. Later on, the different communication methods up to date are analyzed to further understand their limitations.
2017-03-28
Technical Paper
2017-01-0860
PengBo Dong, Jun Yamauchi, Keiya Nishida, Youichi Ogata
Abstract With the aim of improving engine performance, recent trend of fuel injection nozzle design followed by engineers and researchers is focusing on more efficient fuel break up, atomization, and fuel evaporation. Therefore, it is crucial to characterize the effect of nozzle geometric design on fuel internal flow dynamics and the consequent fuel-air mixture properties. In this study, the internal flow and spray characteristics generated by the practical multi-hole (10 holes) nozzles with different nozzle hole length and hole diameter were investigated in conjunction with a series of computational and experimental methods. Specifically, the Computational Fluid Dynamics (CFD) commercial code was used to predict the internal flow variation inside different nozzle configurations, and the high-speed video observation method was applied to visualize the spray evolution processes under non-evaporating conditions.
2017-03-28
Journal Article
2017-01-1621
Andre Kohn, Karsten Schmidt, Jochen Decker, Maurice Sebastian, Alexander Züpke, Andreas Herkersdorf
Abstract The increasing complexity of automotive functions which are necessary for improved driving assistance systems and automated driving require a change of common vehicle architectures. This includes new concepts for E/E architectures such as a domain-oriented vehicle network based on powerful Domain Control Units (DCUs). These highly integrated controllers consolidate several applications on different safety levels on the same ECU. Hence, the functions depend on a strictly separated and isolated implementation to guarantee a correct behavior. This requires middleware layers which guarantee task isolation and Quality of Service (QoS) communication have to provide several new features, depending on the domain the corresponding control unit is used for. In a first step we identify requirements for a middleware in automotive DCUs. Our goal is to reuse legacy AUTOSAR based code in a multicore domain controller.
2017-03-28
Journal Article
2017-01-1605
Paul Chambon, Dean Deter, David Smith, Grant Bauman
Abstract Electric drives, whether in battery electric vehicles (BEVs) or various other applications, are an important part of modern transportation. Traditionally, physics-based models based on steady-state mapping of electric drives have been used to evaluate their behavior under transient conditions. Hardware-in-the-Loop (HIL) testing seeks to provide a more accurate representation of a component’s behavior under transient load conditions that are more representative of real world conditions it will operate under, without requiring a full vehicle installation. Oak Ridge National Laboratory (ORNL) developed such a HIL test platform capable of subjecting electric drives to both conventional steady-state test procedures as well as transient experiments such as vehicle drive cycles.
2017-03-28
Journal Article
2017-01-1615
Hariharan Venkitachalam, Christian Granrath, Balachandar Gopalakrishnan, Johannes Richenhagen
Abstract Ensuring software quality is one of the key challenges associated with the development of automotive embedded systems. Software architecture plays a pivotal role in realizing functional and non-functional requirements for automotive embedded systems. Software architecture is a work-product of the early stages of software development. The design errors introduced at the early stages of development will increase cost of rework. Hence, an early evaluation of software architecture is important. PERSIST (Powertrain control architecture Enabling Reusable Software development for Intelligent System Tailoring) is a model-based software product line approach which focuses on cross-project standardization of powertrain software. The product line is characterized by common design guidelines and adherence to industry standards like ISO 25010, AUTOSAR and ISO 26262.
2017-03-28
Journal Article
2017-01-1639
Gerard W. Malaczynski, Gregory Roth
Abstract Onboard diagnostic regulations require performance monitoring of diesel particulate filters used in vehicle aftertreatment systems. Delphi has developed a particulate matter (PM) sensor to perform this function. The objective of this sensor is to monitor the soot (PM) concentration in the exhaust downstream of the diesel particulate filter which provides a means to calculate filter efficiency. The particulate matter sensor monitors the deposition of soot on its internal sensing element by measuring the resistance of the deposit. Correlations are established between the soot resistance and soot mass deposited on the sensing element. Currently, the sensor provides the time interval between sensor regeneration cycles, which, with the knowledge of the exhaust gas flow parameters, is correlated to the average soot concentration.
Viewing 211 to 240 of 16441