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Viewing 241 to 270 of 22790
2016-04-05
Technical Paper
2016-01-1066
Isamu Shiotsu, Kisaburo Hayakawa, Hiroyuki Nishizawa
Abstract A new engine starter is developed for the purposes of downsizing and improving response time. A feed screw is used in the proposed starter, and its behavior is as follows. The motor shaft connected to the feed screw rotates, and the pinion gear with an internal screw then moves along its axis and stops at the end of the screw. The ring gear connected to the engine is located at the same axial position at which the pinion gear stops. Therefore, the pinion gear is engaged with the ring gear, and the engine is turned over. While a conventional starter requires a solenoid actuator to move the pinion gear, this device does not because the rotational movement of the screw is converted to the axial movement of the pinion gear. However, there is a problem whereby the rotational speed of the motor shaft decreases when the gear pair is engaged. This problem is resolved by adding a coil spring between the pinion gear and the end of the screw.
2016-04-05
Technical Paper
2016-01-1114
Jinsung Kim
Abstract A dry clutch induces judder phenomenon which is caused by variations in the vehicle load condition and frictional material properties. Such a problem may lead to the stick-slip limit cycle that results in undesired longitudinal vibrations of vehicles. To solve this problem, a vibration suppression control is proposed. The amplitude of vibrations is detected by the signal conditioning from the measurements with the transmission input shaft speed and the wheel speed sensors. Based upon this, a perturbation torque is applied additionally on the nominal launch controller to make the drive shaft oscillation vanish. It can be achieved by the control design without any extra hardware cost. Finally, experimental results confirm the effectiveness of the proposed mechanism.
2016-04-05
Technical Paper
2016-01-1210
Koji Shiozaki, Ken Toshiyuki, Jae Seung Lee, Kyosuke Miyagi, Adam Barkley, Zach Cole, Brandon Passmore, Ty McNutt, Alexander B. Lostetter
Abstract This paper presents a new application of a vehicle on-board battery charger utilizing high frequency Silicon Carbide (SiC) power devices. SiC is one of the most promising alternatives to Silicon (Si) for power semiconductor devices due to its superior material characteristics such as lower on-state resistance, higher junction temperature, and higher switching frequency. An on-board charger prototype is developed demonstrating these advantages and a peak system efficiency of 95% is measured while operating with a switching frequency of 250 kHz. A maximum output power of 6.06 kW results in a gravimetric power density of 3.8 W/kg and a volumetric power density of 5.0 kW/L, which are about 10 times the densities compared with the current Prius Plug-In Si charger. SiC technology is indispensable to eco-friendly PHV/EV development.
2016-04-05
Technical Paper
2016-01-1212
Yupu Chen, Miaohua Huang
Abstract 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't 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
2016-01-1211
Hua Tian, WeiGuang Wang, Ge-Qun Shu, Xingyu Liang, Haiqiao Wei
Abstract Power lithium-ion battery is the core component of electric vehicles and hybrid electric vehicles (EVs and HEVs). Thermal management at different operating conditions affects the life, security and stability of lithium-ion battery pack. In this paper, a one-dimensional, multiscale, electrochemical-thermal coupled model was applied and perfected for a flat-plate-battery pack. The model is capable of predicting thermal and electrochemical behaviors of battery. To provide more guidance for the selection of thermal management, temperature evolutions and distributions in the battery pack at various ambient temperatures, discharge rates and thermal radiation coefficients were simulated based on six types of thermal management (adiabatic, natural convection, air cooling, liquid cooling, phase change material cooling, isothermal).
2016-04-05
Technical Paper
2016-01-1213
Ram Vijayagopal, Kevin Gallagher, Daeheung Lee, Aymeric Rousseau
Abstract Present-day battery technologies support a battery electric vehicle with a 300mile range (BEV 300), but the cost of such a vehicle hinders its large-scale adoption by consumers. The U.S. Department of Energy (DOE) has set aggressive cost targets for battery technologies. At present, no single technology meets the cost, energy, and power requirements of a BEV 300, but a combination of multiple batteries with different capabilities might be able to lower the overall cost closer to the DOE target. This study looks at how such a combination can be implemented in vehicle simulation models and compares the vehicle manufacturing and operating costs to a baseline BEV 300. Preliminary analysis shows an opportunity to modestly reduce BEV 300 energy storage system cost by about 8% using a battery pack that combines an energy and power battery. The baseline vehicle considered in the study uses a single battery sized to meet both the power and energy requirements of a BEV 300.
2016-04-05
Technical Paper
2016-01-1217
Erik Yen, Kuo-huey Chen, Taeyoung Han, Bahram Khalighi
Abstract The Computer-Aided Engineering of Automotive Batteries (CAEBAT) Phase 1 project is a U.S. Department of Energy-funded, multi-year project which is aimed at developing a complete CAE tool set for the automotive battery pack design. This paper reports the application of the full field approach of the CAEBAT which is developed by the General Motors-led industry team, for a 24-cell liquid-cooled prototype battery pack. It also summarizes the verification of the approach by comparing the simulation results with the measurement data. The simulation results using the Full Field Approach are found to have a very good agreement with the measurement data.
2016-04-05
Technical Paper
2016-01-1215
Zhenhai Gao, Xiaoting Zhang, Hongyu Hu, Dalei Guo, Hui Zhao, Huili Yu
Abstract The poor low-temperature behavior of Li-ion batteries has limited its application in the field of electric vehicles and hybrid electric vehicles. Many previous studies concentrate on developing new type of electrolyte to solve this problem. However, according to recent research, the key limitation at low temperature is the low diffusivity of lithium ion in the anode electrodes. Hence, it is potential to study anode materials to improve low-temperature behavior of LIBs. ZnFe2O4 with higher theoretical capacity is low toxicity and abundance, contributing to its commercial application. Different ZnFe2O4 crystalline shapes have different particle sizes. Among them, the cubic ZnFe2O4 with smaller particle size will increase its own electronic and ionic conductance at lower temperature. In this regard, we evaluated low-temperature performance of LIBs with ZnFe2O4 cubes as anode materials at -25°C.
2016-04-05
Journal Article
2016-01-1219
Hua Bai, Matt McAmmond, Juncheng Lu, Qi Tian, Hui Teng, Alan Brown
Abstract Most of the present EV on-board chargers utilize a three-stage design, e.g., AC/DC rectifier, DC to high-frequency AC inverter, and AC to DC rectifier, which limits the wall-to-battery efficiency to ∼94%. To further increase the efficiency and power density, a matrix converter is an excellent candidate directly converting grid AC to high-frequency AC thereby saves one stage. However, its control complexity and the high cost of building the back-to-back switches are barriers its acceptance. Instead, this paper adopts the 650V E-mode GaN HEMTs to build a level-2 on-board charger using the indirect matrix topology. The input voltage is 80∼260VAC, the battery voltage is 200∼500VDC and the rated power is 7.2kW. Variable switching frequency is combined with phase-shift control to realize the zero-voltage switching. To further increase the system efficiency, four GaN HEMTs are paralleled to form one switching module with a novel gate-drive technology.
2016-04-05
Technical Paper
2016-01-1226
Takefumi Kaji, Yuki Amano, Hiromitsu Asai
Abstract In automobiles, Integrated Starter Generators (ISGs) are important components since they ensure significant fuel economy improvements. With motors that operate at high voltage such as ISGs, it is important to accurately know partial discharge inception voltages (PDIVs) for the assured insulation reliability of the motors. However, the PDIVs vary due to various factors including the environment (temperature, atmospheric pressure and humidity), materials (water absorption and degradation) and voltage waveforms. Consequently, it is not easy either empirically or analytically to ascertain the PDIVs in a complex environment (involving, for example, high temperature, low atmospheric pressure and high humidity) in which many factors vary simultaneously, as with invehicle environments. As a well-known method, PDIVs can be analyzed in terms of two voltage values, which are the breakdown voltage of the air (called “Paschen curve”) and the shared voltage of the air layer.
2016-04-05
Technical Paper
2016-01-1229
Douglas Cesiel, Charles Zhu
Abstract The electric vehicle on-board charger (OBC) is responsible for converting AC grid energy to DC energy to charge the battery pack. This paper describes the development of GM’s second generation OBC used in the 2016 Chevrolet Volt. The second generation OBC provides significant improvements in efficiency, size, and mass compared to the first generation. Reduced component count supports goals of improved reliability and lower cost. Complexity reduction of the hardware and diagnostic software was undertaken to eliminate potential failures.
2016-04-05
Technical Paper
2016-01-1634
Atul Bansal, Anoop Jain, Prateek Srivastava, Anant Kumar Tiwary, Rishi Kumar Dear
A tire is one of the most important performance and safety components in a two wheeler. An incorrect tire pressure not only impacts overall performance of a vehicle but also safety and overall fuel economy. The main purpose for appropriate tire pressure is to uniformly distribute vehicle load across the tire contact patch thereby providing an optimal contact between tire and road, effective handling, passenger comfort, maximum tire life and overall vehicle safety. A Tire Pressure Monitoring System (TPMS) measures a range of air pressure and alerts for proper tire pressure maintenance. Currently fully fledged tire pressure sensing systems are used in passenger cars and commercial vehicles. The use of such system in a two wheeler is yet to be recognized as precondition instead of an added attribute.
2016-04-05
Technical Paper
2016-01-1638
Eunhyek Joa, Kyongsu Yi, Kilsoo Kim
Abstract This paper presents the integrated chassis control(ICC) of four-wheel drive(4WD), electronic stability control(ESC), electronic control suspension(ECS), and active roll stabilizer(ARS) for limit handling. The ICC consists of three layers: 1) a supervisor determines target vehicle states; 2) upper level controller calculates generalized forces; 3) lower level controller, which is contributed in this paper, optimally allocates the generalized force to chassis modules. The lower level controller consists of two integrated parts, 1) longitudinal force control part (4WD/ESC) and 2) vertical force control part (ECS/ARS). The principal concept of both algorithms is optimally utilizing the capability of the each tire by monitoring tire saturation, with tire combined slip. By monitoring tire saturation, 4WD/ESC integrated system minimizes the sum of the tire saturation, and ECS/ARS integrated system minimizes the variance of the tire saturation.
2016-04-05
Journal Article
2016-01-1653
Zhenhai Gao, Jun Wang, Hongyu Hu, Dazhi Wang
Abstract Vehicle Longitudinal Control (VLC) algorithm is the basis function of automotive Cruise Control system. The main task of VLC is to achieve a longitudinal acceleration tracking controller, performance requirements of which include fast response and high tracking accuracy. At present, many control methods are used to implement vehicle longitudinal control. However, the existing methods are need to be improved because these methods need a high accurate vehicle dynamic model or a number of experiments to calibrate the parameters of controller, which are time consuming and costly. To overcome the difficulties of controller parameters calibration and accurate vehicle dynamic modeling, a vehicle longitudinal control algorithm based on iterative learning control (ILC) is proposed in this paper. The algorithm works based on the information of input and output of the system, so the method does not require a vehicle dynamics model.
2016-04-05
Technical Paper
2016-01-1629
Gaspar Luis Gil Gómez, Johannes Vestlund, Egbert Bakker, Christian Berger, Mikael Nybacka, Lars Drugge
Abstract Vehicle dynamics development relies on subjective assessments (SA), which is a resource-intensive procedure requiring both expert drivers and vehicles. Furthermore, development projects becoming shorter and more complex, and increasing demands on quality require higher efficiency. Most research in this area has focused on moving from physical to virtual testing. However, SA remains the central method. Less attention has been given to provide better tools for the SA process itself. One promising approach is to introduce computer-tablets to aid data collection, which has proven to be useful in medical studies. Simple software solutions can eliminate the need to transcribe data and generate more flexible and better maintainable questionnaires. Tablets’ technical features envision promising enhancements of SA, which also enable better correlations to objective metrics, a requirement to improve CAE evaluations.
2016-04-05
Technical Paper
2016-01-1499
Willy Klier, Thomas Lich, Gian Antonio D’Addetta, Heiko Freienstein, Armin Koehler, Bastian Reckziegel, Zerong Yu
Abstract On the way to automated driving, the installation rate of surround sensing systems will rapidly increase in the upcoming years. The respective technical progress in the areas of driver assistance and active safety leads to a numerous and valuable information and signals to be used prior to, during and even after an accident. Car makers and suppliers can make use of this new situation and develop integrated safety functions to further reduce the number of injured and even deaths in car accidents. Nevertheless, the base occupant safety remains the core of this integrated safety system in order to ensure at least a state-of-the-art protection even in vehicles including partial, high or full automation. Current networked safety systems comprehend a point-to-point connection between single components of active and safety systems. The optimal integration requires a much deeper and holistic approach.
2016-04-05
Technical Paper
2016-01-1510
Chinmoy Pal, Tomosaburo Okabe, Kulothungan Vimalathithan, Jeyabharath Manoharan, Pratapnaidu Vallabhaneni, Munenori Shinada, Kazuto Sato
Abstract Many active safety systems are being developed with the intent of protecting pedestrians namely; pedestrian airbags, active hood, active emergency braking (AEB), etc. Effectiveness of such protection system relies on the efficiency of the sensing systems. The pop-uphood system was developed to help reduce pedestrian head injuries. A pop-up system is expected to make full deployment of the hood before the pedestrian’s head could hit the hood. The system should have the capability to detect most road users ranging from a six year old (6YO) child to a large male. To test the sensing system, an impactor model (PDI-2) was developed. Sensor response varies for vehicles with different front end profile dimensions.
2016-04-05
Technical Paper
2016-01-1547
Jun Yin, Xinbo Chen, Lixin Wu, Jianqin Li
Abstract Traditional active suspension which is equipped with hydraulic actuator or pneumatic actuator features slow response and high power consumption. However, electromagnetic actuated active suspension benefits quick response and energy harvesting from vibration at the same time. To design a novel active and energy regenerative suspension (AERS) utilizing electromagnetic actuator, this paper investigates the benchmark cars available on the market and summaries the suspension features. Basing on the investigation, a design reference for AERS design is proposed. To determine the parameters of the actuator, a principle is proposed and the parameters of the actuator are designed accordingly. Compared the linear type and rotary type Permanent Magnet Synchronous Motor (PMSM), the rotary type is selected to construct the actuator of the AERS. Basing on the suspension structure of the design reference model and utilizing rotary type PMSM, a novel AERS structure is proposed.
2016-04-05
Technical Paper
2016-01-1322
Tonghang Zhao, Xining Liu, Yuntao Cao, Chao Li, Hangsheng Hou
Abstract A hybrid electric vehicle (HEV) will start the engine which drives its motor to charge the battery even at idle whenever the battery power is detected to be insufficient. The activation of idle battery charging could lead to serious NVH problems if powertrain parameters are not designed or calibrated properly. This work is focused on a noise issue encountered during idle charging for a specific prototype vehicle, and investigates control strategies to contain the noise level. Based on basic principles of automobile vibration and noise control along with the specific characteristics of the hybrid vehicle architecture, this work analyzes and elucidates methods of the engine idle charging noise control from the perspectives of powertrain modal alignment, idle speed optimization, and electric motor control algorithm.
2016-04-05
Technical Paper
2016-01-1667
Long Chen, Shuwei Zhang, Mingyuan Bian, Yugong Luo, Keqiang Li
Abstract As a typical parameter of the road-vehicle interface, the road friction potential acts an important factor that governs the vehicle motion states under certain maneuvering input, which makes the prior knowledge of maximum road friction capacity crucial to the vehicle stability control systems. Since the direct measure of the road friction potential is expensive for vehicle active safety system, the evaluation of this variable by cost effective method is becoming a hot issue all these years. A ‘wheel slip based’ maximum road friction coefficient estimation method based on a modified Dugoff tire model for distributed drive electric vehicles is proposed in this paper. It aims to evaluate the road friction potential with vehicle and wheel dynamics analyzing by using standard sensors equipped on production vehicle, and fully take the advantage of distributed EV that the wheel drive torque and rolling speed can be obtained accurately.
2016-04-05
Journal Article
2016-01-1660
Takahiro Okano, Akira Sakai, Yusuke Kamiya, Yoshio Masuda, Tomoyuki Yamaguchi
Abstract The use of hybrid, fuel cell electric, and pure electric vehicles is on the increase as part of measures to help reduce exhaust gas emissions and to help resolve energy issues. These vehicles use regenerative-friction brake coordination technology, which requires a braking system that can accurately control the hydraulic brakes in response to small changes in regenerative braking. At the same time, the spread of collision avoidance support technology is progressing at a rapid pace along with a growing awareness of vehicle safety. This technology requires braking systems that can apply a large braking force in a short time. Although brake systems that have both accurate hydraulic control and large braking force have been developed in the past, simplification is required to promote further adoption.
2016-04-05
Technical Paper
2016-01-1682
Pratap Dinkar Thorat, Shailesh Newase, Keyur Gupte, Pushkaraj Kaulgud
Abstract Electrical Power and Signal Distributions System in a vehicle is the most important among the Automotive Electrical and Electronic systems. In fact any electrical or electronic systems are realized and are physically formed by the Electrical Wiring Harness. This is a system in itself with the set of wires and connectors connecting various devices to feed the power and act as physical channels for signal transmission and serial data communication. Thus, the Electrical Wiring Harness becomes huge complicated systems in a vehicle. Because of the number of wires, cables and the specific connectivity requirement the design and development will become very difficult. Further, the complexity is manifold due to number of harnesses in a vehicle and different operating conditions in different zones of the vehicle. The design and development of an Electrical Wiring Harness involves primarily the design of the electrical circuit. This is based on the vehicle architecture.
2016-04-05
Technical Paper
2016-01-1582
Dirk Wieser, Sabine Bonitz, Lennart Lofdahl, Alexander Broniewicz, Christian Nayeri, Christian Paschereit, Lars Larsson
Abstract Flow visualization techniques are widely used in aerodynamics to investigate the surface trace pattern. In this experimental investigation, the surface flow pattern over the rear end of a full-scale passenger car is studied using tufts. The movement of the tufts is recorded with a DSLR still camera, which continuously takes pictures. A novel and efficient tuft image processing algorithm has been developed to extract the tuft orientations in each image. This allows the extraction of the mean tuft angle and other such statistics. From the extracted tuft angles, streamline plots are created to identify points of interest, such as saddle points as well as separation and reattachment lines. Furthermore, the information about the tuft orientation in each time step allows studying steady and unsteady flow phenomena. Hence, the tuft image processing algorithm provides more detailed information about the surface flow than the traditional tuft method.
2016-04-05
Technical Paper
2016-01-0093
Haizhen Liu, Rui He, Jian Wu, Wenlong Sun, Bing Zhu
Abstract With the development of modern vehicle chassis control systems, such as Anti-Lock Brake System (ABS), Acceleration Slip Regulation (ASR), Electronic Stability Control (ESC), and Regenerative Braking System (RBS) for EVs, etc., there comes a new requirement for the vehicle brake system that is the precise control of the wheel brake pressure. The Electro-Hydraulic Brake system (EHB), which owns an ability to adjust four wheels’ brake pressure independently, can be a good match with these systems. However, the traditional control logic of EHB is based on the PWM (Pulse-Width Modulation), which has a low control accuracy of linear electromagnetic valves. Therefore, this paper presents a research of the linear electro-magnetic valve characteristic analysis, and proposes a precise pressure control algorithm of the EHB system with a feed forward and a PID control of linear electro-magnetic valves.
2016-04-05
Journal Article
2016-01-0092
Stijn Kerst, Barys Shyrokau, Edward Holweg
Abstract Active vehicle safety and driving assistance systems can be made more efficient, more robust and less complex if wheel load information would be available. Although this information could be determined via numerous different methods, due to various reasons, no commercially feasible approach has yet been introduced. In this paper the approach of bearing load estimation is topic of interest. Using the bearing for load measurement has considerable advantages making it commercially attractive as: i) it can be performed on a non-rotating part, ii) all wheel loads can be measured and iii) usually the bearing serves the entire lifetime of the vehicle. This paper proposes a novel approach for the determination of wheel loading. This new approach, based on the strain variance on the surface of the bearing outer ring, is tested on a dedicated bearing test setup.
2016-04-05
Journal Article
2016-01-0094
Jaya Gaitonde, R B Lohani
Abstract Photodetectors are important components in automotive industry. Sensitivity, speed, responsivity, quantum efficiency, photocurrent gain 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, excellent quantum efficiency, high sensitivity, moderate speed, tremendous gain and low power dissipation, surpassing their photodiode, phototransistor and other 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 results are in line with the experiments. The device shows high potential in automotive applications.
2016-04-05
Technical Paper
2016-01-0112
Dariusz Borkowski, Rafal Tomasz Dlugosz, Michał Szulc, Pawel Skruch, Pawel Markiewicz, Dominik Sasin, Marta Kolasa, Tomasz Talaska
Abstract In the presented paper we deal with an important problem in active safety systems, which is the multi-rate processing of different signals. Automotive systems are usually very complex, involving multiple subsystems, in which typically it is very difficult to obtain equal sampling rates. In many cases, this problem is ignored, which means that the signals samples stored in different time moments are silently assumed to be to sampled in the same time. Looking from the point of view of signal processing, this incorrect assumption often causes large harmonic distortions artifacts of processed signals. These distortions, in turn, generate harmonics of different frequencies. As a result, if processed signals are used to calculate the trajectories of objects seen by systems associated with the vehicle, may differ from the real world trajectories. This may cause occurrence of false positives or no reaction of the vehicle in case of emergency situation.
2016-04-05
Technical Paper
2016-01-0118
Shinji Niwa, Mori Yuki, Tetsushi Noro, Shunsuke Shioya, Kazutaka Inoue
Abstract This paper presents detection technology for a driver monitoring system using JINS MEME, an eyewear-type wearable device. Serious accidents caused by human error such as dozing while driving or inattentive driving have been increasing recently in Japan. JINS MEME is expected to contribute to reducing the number of traffic deaths by constantly monitoring the driver with an ocular potential sensor. This paper also explains how a driver’s drowsiness level can be estimated from information on their blink rate, which can be calculated from the ocular potential.
2016-04-05
Technical Paper
2016-01-0117
Bi-Cheng Luan, I-Hsuan Lee, Han-Shue Tan, Kang Li, Ding Yuan, Fang-Chieh Chou
Abstract This paper presents the design and implementation of a new steering control method for lane following control (LFC) using a camera. With the road information provided by the image sensor, the LFC system calculates the steering command based on the Target and Control (T&C) driver steering model. The T&C driver model employs a look-ahead control structure to capture the drivers’ core steering mechanism. Based on the models of the steering actuator and the vehicle dynamics, optimal control gains can be determined for any given look-ahead distance (normalized by the vehicle speed). With these simple gains, the vehicle can track very well along the center of the lane. This LFC system was first simulated under the Model-in-the-Loop (MiL) test using the CarSim simulation. The simulations show that the resultant lateral offsets are smaller than those from typical driver models.
2016-04-05
Technical Paper
2016-01-0115
Dev S. Kochhar, Hong Zhao, Paul Watta, Yi Murphey
Abstract Lane change events can be a source of traffic accidents; drivers can make improper lane changes for many reasons. In this paper we present a comprehensive study of a passive method of predicting lane changes based on three physiological signals: electrocardiogram (ECG), respiration signals, and galvanic skin response (GSR). Specifically, we discuss methods for feature selection, feature reduction, classification, and post processing techniques for reliable lane change prediction. Data were recorded for on-road driving for several drivers. Results show that the average accuracy of a single driver test was approx. 70%. It was greater than the accuracy for each cross-driver test. Also, prediction for younger drivers was better.
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