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Viewing 91 to 120 of 22453
2016-04-05
Technical Paper
2016-01-0068
Yoshihiro Ujiie, Tomoyuki Haga, Takeshi Kishikawa, Tohru Wakabayashi, Yoshihiko Kitamura, Hideki Matsushima, Masato Tanabe, Jun Anzai
Controller Area Network (CAN) is a technology widely adopted among vehicles but its vulnerability has been pointed out recently. Many countermeasures have been proposed, but none of them can be deemed as a generic solution. One reason is that those proposed countermeasures all require a heavy level of modification to the existing in-vehicle system.In order to accomplish this problem, we propose new methods to protect CAN network without affecting the existing system. In this paper, we explain the principle of our proposed method as well as the architecture of the Electronic Control Unit (ECU) that implements it, report the result of our experiments, and show the effects against spoofing attacks as well as Denial of Service (DoS) attacks.
2016-04-05
Technical Paper
2016-01-0091
Hikaru Watanabe, Tsutomu Segawa, Takumi Okuhira, Hiroki Mima, Norishige Hoshikawa
This paper presents a custom integrated circuit (IC) on which circuit functions necessary for “Active Hydraulic Brake (AHB) system” are integrated, and its key component, “Current-to-Digital Converter” for solenoid current measurement. The AHB system, which realizes a seamless brake feeling for Antilock Brake System (ABS) and Regenerative Brake Cooperative Control of Hybrid Vehicle, and the custom IC are installed in the 4th-generation Prius released in 2015. In the AHB system, as linear solenoid valves are used for hydraulic brake pressure control, high-resolution and high-speed sensing of solenoid current with ripple components due to pulse width modulation (PWM) is one of the key technologies. The proposed current-to-digital converter directly samples the drain-source voltage of the sensing DMOS (double-diffused MOSFET) with an analog-to-digital (A/D) converter (ADC) on the IC, and digitizes it.
2016-04-05
Technical Paper
2016-01-1212
Yupu Chen, Miaohua huang
Lithium-ion battery plays a key role in electric vehicles, which is critical to the system availability. One of the most important aspects in battery managements systems(BMS) in electric vehicles is the stage of health(SOH) estimation. The state of health (SOH) estimation is very critical to battery management system to ensure the safety and reliability of EV battery operation. The classical approach of current integration(coulomb counting) can not get the accurate values because of accumulative error. In order to provide timely maintenance and replacements of electric vehicles, several estimation approaches have been proposed to develop a reliable and accurate battery state of health estimation. A common drawback of previous algorithm is that the computation quantity is huge and not quite accurate, that is updated partially in this study.
2016-04-05
Technical Paper
2016-01-0135
Ji Zhang, Mengjing Shen, Xiangyu zhu, Qipeng Chen
Nowadays researches of automotive electromagnetic field mainly focus on the component level and electromagnetic compatibility, while there is a lack of relevant studies on internal electromagnetic environment of the vehicles. With the increasingly complex internal electromagnetic environment of the vehicle, people are increasingly concerned about its potential impact of human health. This article researches on a type of electric vehicle and the occupants and analyses its electromagnetic radiation effects on human health. Firstly, considering the characters of Pro/E, Hypermesh and FEKO, the “Characteristics grouping subdivision” method is used to establish the entire vehicle body FE model. According to the requirement of MOM/FEM method, the entire vehicle model is optimized to be a high quality body model with simple construction and moderate grid size.
2016-04-05
Technical Paper
2016-01-1197
Zhengbin Wu, Rongcheng Weng, Zhiqun zhang, Juan Li
Lithium-ion battery is in an increasing demand for alternative energy vehicles, grid storage systems and consumer electronics for its long cycle life, relatively high energy density and safety. It is important to achieve the accurate dynamic performance of lithium-ion battery for practical applications. Associating the electrochemical phenomena of a battery with electrical and non-electrical components, equivalent circuit models are normally more computation efficient compared to electrochemical models. In this paper, a novel equivalent circuit model for lithium-ion battery having inductive and capacitive components with the complex parameters is proposed. The corresponding imaginary part of these complex parameters represents the frequency-dependent dissipation characteristics from different electrochemical and physical aspects in this proposed battery model.
2016-04-05
Technical Paper
2016-01-1191
Saher Al Shakhshir, Torsten Berning
Proton exchange membrane fuel cells (PEMFC’s) are currently being commercialized for various applications ranging from automotive (e.g. the Toyota Mirai) to stationary such as powering telecom back-up units. In PEMFC’s, oxygen from air is internally combined with hydrogen to form water and produce electricity and waste heat. One critical technical problem of these fuel cells is still the water management: the proton exchange membrane in the center of these fuel cells has to be hydrated in order to stay proton-conductive while on the other hand excessive liquid water can lead to cell flooding and increased degradation rates. Clearly, a fundamental understanding of all aspects of water management in PEMFC is imperative. This includes the fuel cell water balance, i.e. which fraction of the product water leaves the fuel cell via the anode channels versus the cathode channel.
2016-04-05
Technical Paper
2016-01-1117
Jun Sun, xiaofei Pei, Xuexun Guo, Yanqiang Zhao
Abstract: In order to overcome hysteresis and dead zone problems caused by friction in the proportional solenoid valve, improve rapidity and stability of the pneumatic system on hydraulic retarder, a closed-loop control strategy based on valve coil current is proposed. The high-frequency low-amplitude dither signal is introduced into the proportional solenoid valve. By adding proper dither signal, the stick-slip motion of the valve will be transformed into a steady one, and the dynamic performance will be improved. Consequently, lower retarder response time during gear changes. The proportional valve coil current is measured as a feedback to construct a closed-loop control strategy. Combining with the closed-loop strategy the PI control algorithm is adopted to make sure that valve current is adjusted to the target value. Pulse Width Modulation (PWM) signal is used as proportional solenoid valve drive signal.
2016-04-05
Technical Paper
2016-01-1229
Douglas Cesiel, Charles Zhu
Manufacturers have introduced several types of electric vehicles that utilize on-board charging systems; including Battery Electric Vehicles (BEV), Extended Range Electric Vehicles (EREV), and Plug-in Hybrid Electric Vehicles (PHEV). These vehicles include an on-board power conversion system that allows the DC propulsion battery to be charged using energy from the AC power grid. The primary component within the charging system is an AC/DC conversion module known as the On-Board Charger (OBC). The efficiency of the charging system directly effects overall vehicle efficiency. Losses in the charging system correspond to AC grid energy that is consumed but does not contribute to increasing the battery state of charge. Reducing losses also reduces the work required of the cooling system during battery charging, and this further improves overall efficiency. Thus, OBC efficiency improvement was an important objective for GM.
2016-04-05
Technical Paper
2016-01-0115
Dev S. Kochhar, Hong Zhao, Paul Watta, Yi Murphey
Intended or unintended lane changes are documented occasions when an accident may occur. Drivers can make improper lane changes when they do not see surrounding traffic (the blind spot problem), or when they may be drowsy or distracted, or impaired by alcohol or drugs. In this paper we present a comprehensive study on predicting the driver’s intent to make a lane change based on continuous monitoring and evaluation of the driver’s physiological measures. The task of an intentional lane change involves several cortical and sub-cortical processes, which, in turn, are reflected in physiological measures. In our previous work we introduced a real-time data acquisition system for acquiring three types of driver physiological measures, namely, the Electrocardiogram (ECG), Respiration signal, and Galvanic Skin Response (GSR). A statistical signal selection algorithm and a neural network trained to predict lane change was also introduced.
2016-04-05
Technical Paper
2016-01-0655
Farid Bahiraei, Amir Fartaj, Gholm-Abbas Nazri
Li-ion batteries are leading candidates for hybrid and electric vehicles as environmentally friendly means of transport. The main barriers for widely deployment of these batteries in electric vehicles are safety, cost, and poor low temperature performance, which are all challenges related to battery thermal management system (BTMS). Therefore, an effective thermal management strategy is crucial for enhancing the system lifetime and increasing vehicle range. In this study, a coupled thermal-electrochemical model for prismatic cells is primarily developed to simulate the battery cell chemistry and heat generation. This model is also used to investigate the effectiveness of active and passive cooling systems. The active cooling system under study utilizes cooling plates and water-glycol mixture as the working fluid while the passive cooling system incorporates a phase change material (PCM).
2016-04-05
Technical Paper
2016-01-1194
Panos D. Prezas, L. Somerville, P Jennings, A McGordon, J. K. Basco, T. Duong, I. Bloom
As electrified vehicles become more common in the market place, consumers would expect to have similar experiences as cars powered by an internal-combustion engine. This is especially true when it comes to “refueling” the vehicle. Refueling an internal combustion vehicle takes up to 10-15 min. On the other hand, fully charging a lithium-ion battery system can take 1-2 h. To meet the expectations set by the internal combustion engine, the battery system would have to be charged at the 4-to-6-C rate. Additionally, if a motorist runs out of gasoline on the highway, 20 L of fuel can be quickly added to the tank, partially refilling the tank and enabling the motorist to get to his next destination. The results of our investigation on the effects of fast-charging commercially-available lithium-ion cells on performance, life and physical condition of the electrodes in the cells in both scenarios, full and partial charging, will be presented.
2016-04-05
Technical Paper
2016-01-0040
Ming Meng, Wilson Khoo
The Security Development Lifecycle (SDL) is a software development process that helps developers build more secure software and address security compliance requirements while reducing development cost. The SDL process has been developed to appropriately outline the development process specifically for the consumer electronics oriented mindset. Unfortunately this approach does not always correlate to an appropriate approach from the automotive OEM mindset. This paper will analyze the current SDL process in detail and provide suggestions with improvements to the overall SDL process creating an Automotive Security Development Lifecycle (ASDL).
2016-04-05
Technical Paper
2016-01-0016
Jörg Schäuffele
Agenda: - Trends - Challenges - PREEvision approach - A practical example - Summary and outlook
2016-04-05
Technical Paper
2016-01-0163
Thomas Rothermel, Jürgen Pitz, Hans-Christian Reuss
In the field of electric mobility, one of the key issues is to improve the safety for pedestrians in urban areas with help of Advanced Driver Assistance Systems (ADAS). Due to cruising range restrictions, nowadays electric vehicles are mainly operated in urban areas where risk potential for pedestrian collision is increased. Furthermore low noise emissions, in comparison to conventional internal combustion engine vehicles, lead to a reduced acoustic perception through pedestrians. The paper proposes a framework for semi-autonomous longitudinal guidance for electric vehicles. To lower the risk for pedestrian collisions in urban areas, a velocity reference trajectory which is given by the driver is optimized with respect to safety aspects by means of Nonlinear Model Predictive Control (NMPC). The velocity reference trajectory is determined from accelerator pedal input.
2016-04-05
Technical Paper
2016-01-0462
Chunlei Wang, Xinjie Zhang, Konghui Guo, Fangwu Ma, Dong Chen
With the development of the advanced driver assistance system and autonomous vehicle techniques, a precise description of the driver’s steering behavior with mathematical models has attracted a great attention. However, the driver’s steering maneuver demonstrates the stochastic characteristic due to a series of complex and uncertain factors, such as the weather, road, and driver’s physiological and psychological limits, generating negative effects on the performance of the vehicle or the driver assistance system. Hence, this paper explores the stochastic characteristic of driver’s steering behavior and a novel steering controller considering this stochastic characteristic is proposed based on stochastic model predictive control (SMPC). Firstly, a search algorithm is derived to describe the driver’s road preview behavior.
2016-04-05
Technical Paper
2016-01-1495
Motomi Iyoda, Tom Trisdale, Rini Sherony, Daniel Mikat, William Rose
EDR (Event Data Recorder) is a function of recording vehicle status at the timing of accident. Toyota introduced EDR from August 2000 one after the other. Now about 70% of Toyota vehicles in North America have EDR. This is more than about 50% EDR coverage of all vehicles in North America. There is EDR regulation in USA, so we record EDR data based on the regulation. We think this is the minimum requirement and we record additional necessary data required from accident reconstruction. They are, (1) additional pre-crash data, (2) additional side crash recording system, (3) roll over recording system, (4) pedestrian protection PUH (Pop Up Hood) recording system, (5) non-crash triggered recording system VCH (Vehicle Control History), etc. Commercially available tool is necessary for EDR data retrieval, based on the regulation in USA. So we adopted BOSCH CDR (Crash Data Retrieval). All Toyota EDR can be retrieved using CDR for all over the world including North America.
2016-04-05
Technical Paper
2016-01-0459
Jian Zhao, Jing Su, Bing Zhu, Jingwei Shan
Indirect Tire Pressure Monitoring System (TPMS) is a system which monitors the tire pressure based on the wheel speed signals from Anti-lock Brake System (ABS). In this paper, a practical indirect TPMS method is proposed to estimate the tire pressure according to the relationship between the tire pressure and the tire circumferential vibration. Firstly, the error of ABS wheel speed sensor system caused by the machining tolerance of the tooth ring are estimated based on the measured wheel speed using Recursive Least Squares algorithm. Then, the measuring error is eliminated and the vibration noise is further extracted from the from the wheel speed signal. Using the vibration noise, the resonance frequency of the tire vibration system was extracted by Maximum Entropy Spectral Estimation (MESE) based on Auto-regressive (AR) model.
2016-04-05
Technical Paper
2016-01-0045
Takanori Uno, Akahori Ichiro, Iwata Yasuaki
In this paper, consideration is made to create a simulation model of BCI test method, which is one of the EMC evaluation methods for in-vehicle electronic devices, and an intrinsic model of BCI probe is provided. Using this model, it is demonstrated that when the impedance of the BCI probe is sufficiently high, the BCI probe serves as a transformer with the coil turn ratio of 1:1, and the admittance of a line or a load connected to each wire becomes proportional to the magnitude of current flowing each wire. This model also can be applied when leakage inductance inside the BCI probe is taken into consideration. The validity of this model is verified by the experiment using a jig which can clamp multiple wires. In addition, by using this model, it is demonstrated that S-parameters when dozens of wires are clamped with the BCI probe can be generated from the measurement results of S-parameters when one wire is clamped.
2016-04-05
Technical Paper
2016-01-1415
William T. Neale, James Marr, David Hessel
This paper presents a methodology for generating photo realistic computer simulation environments of nighttime driving scenarios by combining nighttime photography and videography with video tracking and projection mapping technologies. Nighttime driving environments contain complex lighting conditions such as forward and signal lighting systems of other vehicles, street lighting, and retro reflective markers and signage. The high dynamic range of nighttime lighting conditions make modeling of these systems difficult to render realistically. Photography and video, especially when using high dynamic range imaging, can produce realistic representations of the lighting environments, but without a computer generated environment, the scenarios that can be represented are limited to the specific scenario recorded.
2016-04-05
Technical Paper
2016-01-1214
Hillol Kumar Roy, Andrew McGordon, Paul A Jennings
Battery sizing has significant importance for the performance of hybrid electric vehicles (HEVs). Although several research has been done over the years for the battery sizing, no research has focused on battery system efficiency which affects fuel economy. This paper has investigated battery system efficiencies of different optimum battery sizes which were optimised using two design optimisation methodologies. The first methodology considered a single driving pattern at a time, whereas, the second methodology considered different driving patterns simultaneously for the optimisation. The study considered a simulation model of a power-split HEV for the optimisation of battery size along with internal combustion engine, motor, and generator. An electric-assist charge sustaining supervisory control strategy was considered as the energy management. The maximum speed, acceleration, and gradeability were considered as design constraints.
2016-04-05
Technical Paper
2016-01-1203
Zhang Qiao, Weiwen Deng, Jian Wu
This paper describes a novel power management control strategy of battery and supercapacitor hybrid energy storage system for electric vehicle to improve system efficiency and battery lifetime. The battery lifetime may be dramatically impacted by frequent charge or discharge current resulted from the rapid variation of the load power demand. In the presented research, the high and low frequency power demand in the load is separated by a Haar wavelet transform algorithm to overcome the problem of battery overload work and associated degeneration in battery lifetime resulting from an ineffective distribution between battery and supercapacitor. The purpose of frequency distribution is that the supercapacitor is used to share high frequency power components of load power demand to smooth the power demand applied to battery. As a result, the low frequent power can be shared by battery. This control strategy can be specifically referred to as sole frequency control.
2016-04-05
Technical Paper
2016-01-0073
Peter Subke, Muzafar Moshref
Especially in the production of passenger cars, the reprogramming of electronic control units can be considered as state-of-the art. Today, the automotive industry has to solve the problem that reprogramming of the ever-increasing amount of data takes too long. The CAN bus as interface hit the wall, CAN-FD might solve the problem, Ethernet will do. UDSonIP (ISO 14229) on DoIP (ISO 13400) and Ethernet (IEEE 802.11) are employed in the production of high-class passenger cars. On those vehicles, former discretionary pins of the OBD connector (SAE J1962) are used for the wired connection of external test equipment that supports UDSonIP. With a device that that fits the OBD connector and acts as a bridge between the Ethernet signals to WLAN, external test equipment that supports wireless communication, can be connected to the vehicle. Examples for such wireless devices include smart phones and tablets.
2016-04-05
Technical Paper
2016-01-0082
Satoru Komatsu, Yoshio Karasawa, Tatsuya Kashiwa, Kenji Taguchi, Suguru Imai
Vehicle compatibility of FM receiver (hereafter will be referred to as “FM device”) has been evaluated by obtaining reception characteristics of broadcast waves by repetitive road tests in a certain test environment. Evaluation of reception characteristics while driving had depended on sound evaluation by a limited number of examinees due to a difficulty in quantitative evaluation using actual broadcast waves, thus there had been issues in its reproducibility and objectivity. To solve issues mentioned above, Two-Stage method fading emulator (hereafter will be referred to as “Two-Stage method”) was developed by generating virtual radio wave environment on a calculator. Moreover, multipath distortion rate (MDr) was defined as the benchmark for sound evaluation, and then vehicle compatibility evaluation of FM device was reported at the 2015SAE World Congress. Technical issue of Two-Stage method is to reproduce a radio environment which is identical to actual reception environment.
2016-04-05
Technical Paper
2016-01-0097
Felix Gow, Lifeng Guan, Jooil Park, Jaekwon Kim
TPMS has become a popular system due to regulation in many countries. TPMS consists of sensors that measure air pressure and temperature in the tires. Each sensor transmits sensor information to TPMS control unit for display purpose via RF. The commercial trailers having a long body (longer than 7 m) require a RF repeater to increase the data transmission range. Located near to rear wheels, RF repeater receives sensor signal in the rear wheels and transmits the signal to TPMS control unit. In this paper, we discuss RF repeater transmits at multiple frequencies in order to increase signal reception. On TPMS control unit, RF receiver is able to tune to receive frequencies used in sensor and RF repeater. Other method for improving reception is to transmit same payload multiple times at same frequency as that of sensor. In the paper, other important specifications are discussed as RF repeater design is concerned. A user’s case of RF repeater is implemented.
2016-04-05
Technical Paper
2016-01-0119
Preeti J. Pillai, Veeraganesh Yalla, Kentaro Oguchi
This paper is an extension of our previous work on the CHASE (Classification by Holistic Analysis of Scene Environment) algorithm, that automatically classifies the driving complexity of a road scene image during day-time conditions and assigns it an ‘Ease of Driving’ (EoD) score. The EoD score is a novel driving metric related to the driving difficulty of road scenes, ranging from ‘A’ (Very Easy) to ‘E’ (Very Difficult). In this paper, we introduce a method to compute the EoD during night-time driving conditions. At night, apart from traffic variations and road type conditions, illumination changes are a major predominant factor that affects the road visibility and the driving easiness. Strong illumination variations are introduced at night from light sources such as traffic lights, building lights, overly-lit streetlights and unlit alleys; posing a challenge for the onboard vision system.
2016-04-05
Technical Paper
2016-01-0101
Carl Arft, Yin-Chen Lu, Jehangir Parvereshi
Oscillators are key components in automotive electronics systems. For example, a typical automotive camera module may have three or more oscillators, providing the clocks for microcontrollers, Ethernet controllers, and video chipsets. These oscillators have historically been built around a quartz crystal resonator connected to an analog sustaining circuit driving the crystal to vibrate at its resonant frequency. However, quartz-based devices suffer from poor performance and reliability in harsh automotive environments. SiTime has developed timing solutions based on silicon micro-electromechanical systems (MEMS) technology that exhibit better electromagnetic noise rejection and better performance under shock and vibration. In this paper, we first discuss the design and manufacturing of the MEMS-based device, with emphasis on the specific design aspects that improve reliability and resilience in harsh automotive environments.
2016-04-05
Technical Paper
2016-01-0094
Jaya Gaitonde, R B Lohani
Photodetectors are important components in automotive industry. Sensitivity, speed, responsivity, quantum efficiency and power dissipation are the important characteristics of a photodetector. We report a high performance photodetector based on GaAs Metal- Semiconductor Field Effect Transistor (MESFET), with very high responsivity, high sensitivity, very high quantum efficiency, high speed and low power dissipation, surpassing their photodiode and phototransistor counterparts. A theoretical model of GaAs front illuminated Optical Field Effect transistor is presented. The photovoltaic and photoconductive effects have been taken into account. The gate of the OPFET device has been left open to make a reduction in the number of power supplies. The device shows high potential in automotive applications.
2016-04-05
Technical Paper
2016-01-0643
Jian Zhang, Changwen Liu, Fengrong Bi, Yiqiang Pei, Xiaobo Bi
Knock threshold detection is the key of closed loop control of ignition in gasoline engine, and it is also the difficult point in knock measurement. In this paper, an investigation of knock detection in gasoline direct injection (GDI) engines using bispectrum slice and ensemble empirical mode decomposition (EEMD) based on the engine cylinder head vibration signals. By adding some finite amplitude Gaussian white noises to the signal, EEMD keeps the signal continuous in different time span, and therefore the mode mixing inhering in the classical empirical mode decomposition (EMD) method is alleviated. Power spectrum density (PSD) estimation is used to determine the band range of the resonance frequency generated by knock component. EEMD was used to decompose the original signals, the time-frequency characteristics of the Intrinsic Mode Functions (IMF) were analyzed using Continues Wavelet Transform (CWT) due to its excellent time-frequency resolution.
2016-04-05
Technical Paper
2016-01-1233
Kensuke Sasaki, Apoorva Athavale, Brent Gagas, Takashi Fukushige, Takashi Kato, Robert Lorenz
Variable flux permanent magnet synchronous machines (VF-PMSMs) have been designed by using finite element analysis (FEA) to evaluate speed-torque properties considering magnetization state (MS) manipulation capability. This paper presents a analytical model to estimate speed-torque properties of VF-PMSMs and a process to find preferred magnet dimensions to obtain a specified speed-torque capability requirement in order to accelerate the design process. This model uses an equivalent circuit based analysis to obtain the magnet flux linkage, d-axis inductance (Ld) and demagnetization border in the id-iq plane to maintain a desired MS on the magnet edge, considering VF-PMSM design requirements for magnetization state (MS) manipulation. This model is applied to predict speed-torque properties for several machine designs with a fixed topology, a fixed stator diameter and a fixed stacking length, and varying magnet dimensions, namely, thickness and width.
2016-04-05
Technical Paper
2016-01-1319
Kimitoshi Tsuji, Katsuhiko Yamamoto
It is important for vehicle concept planning to estimate fuel economy and the influence of vehicle vibration in advance using virtual engine specifications and a virtual vehicle frame. In our former study, we showed the 1D physical power plant model with electrical starter, battery that can predict combustion transient torque, combustion heat energy and fuel efficiency. The simulated result agreed with measured data. For idling stop system, the noise and vibration during start up is important factor for salability of the vehicle. In this paper as an application of the 1D physical power plant model, we will show the result of analysis that is starter shaft resonance and the effect on the engine mount vibration of restarting from idle stop. The power plant was 3.5L 6cyl NA. The power plant model was realized by energy based model using VHDL-AMS. Here, VHDL-AMS is modelling language stored in IEC international standard (IEC61691-6) and can realize multi physics on 1D simulation.
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