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Viewing 1 to 30 of 110627
2018-01-19
Journal Article
2018-01-9077
Arya Yazdani, Mehran Bidarvatan
Power split in Fuel Cell Hybrid Electric Vehicles (FCHEVs) has been controlled using different strategies ranging from rule-based to optimal control. Dynamic Programming (DP) and Model Predictive Control (MPC) are two common optimal control strategies used in optimization of the power split in FCHEVs with a trade-off between global optimality of the solution and online implementation of the controller. In this paper, both control strategies are developed and tested on a FC/battery vehicle model, and the results are compared in terms of total energy consumption. In addition, the effects of the MPC prediction horizon length on the controller performance are studied. Results show that by using the DP strategy, up to 12% less total energy consumption is achieved compared to MPC for a charge sustaining mode in the Urban Dynamometer Driving Schedule (UDDS) drive cycle.
2018-01-19
Journal Article
2018-01-9625
Michael Sabisch, Meredith Weatherby, Sandeep Kishan, Carl Fulper
Under contract to the EPA, Eastern Research Group analyzed light-duty vehicle OBD monitor readiness and diagnostic trouble codes (DTCs) using inspection and maintenance (I/M) data from four states. Results from roadside pullover emissions and OBD tests were also compared with same-vehicle I/M OBD results from one of the states. Analysis focused on the evaporative emissions control (evap) system, the catalytic converter (catalyst), the exhaust gas recirculation (EGR) system and the oxygen sensor and oxygen sensor heater (O2 system). Evap and catalyst monitors had similar overall readiness rates (90% to 95%), while the EGR and O2 systems had higher readiness rates (95% to 98%). Approximately 0.7% to 2.5% of inspection cycles with a “ready” evap monitor had at least one stored evap DTC, but DTC rates were under 1% for the catalyst and EGR systems, and under 1.1% for the O2 system, in the states with enforced OBD programs.
2018-01-19
Journal Article
2018-01-9675
Youssef Sabry, Mahmoud Aly, Walid Oraby, Samir El-demerdash
This study aims to take the first step in bridging the gap between vehicle dynamics systems and autonomous control strategies research. More specifically, a nested method is employed to evaluate the collision avoidance ability of autonomous vehicles in the primary design stage theoretically based on both dynamics and control parameters. An integrated model is derived from a half car mathematical model in the lateral direction, consisting of two degrees of freedom, lateral deviation and yaw angle, with a traction mathematical model in the longitudinal direction, consisting of two degrees of freedom, the longitudinal velocity and rolling velocity of the wheel. The integrated model uses a mathematical power train model to generate the torque on the wheel and connects the two systems via the magic formula tyre model to represent the tyre non-linearity during augmented longitudinal and lateral dynamic attitudes. These mathematical models are represented using MATLAB in the time domain.
2018-01-12
Technical Paper
2018-01-9626
Marcus Schmitz, Lena Rittger, Henning Kienast, Alexandra Neukum
Potential collisions with oncoming traffic while turning left belong to the most safety-critical situations with ~25% of all intersection crossing path crashes. A Left Turn Assist (LTA) was developed to reduce the number of crashes. Crucial for the effectiveness of the system is the design of the human machine interface, i.e. defining how the system uses the calculated crash probability in the communication with the driver. A driving simulator study was conducted evaluating a warning strategy for two use cases: firstly, the ego-vehicle comes to a stop before turning (STOP), and secondly, the driver moves on without stopping (MOVE). 40 drivers drove through three STOP and two MOVE scenarios. For the STOP scenarios, the study compared the effectiveness of an audio-visual warning with an additional brake intervention and a baseline. For the MOVE scenarios, the study analyzed the effectiveness of the audio-visual warning against a baseline.
2018-01-12
Journal Article
2018-01-9275
Hamed Kheshtinejad, Mirko Baratta, Danilo Laurenzano, Claudio Maino, Daniela Anna Misul
CNG is at present retaining a growing interest as a factual alternative to traditional fuels for SI engines, thanks to its high potentials in reducing the engine-out emissions. Increasing thrust into the exploitation of NG in the transport field is in fact produced by the even more stringent emission regulations that are being introduced into the worldwide scenario. The present paper aims at deeply investigating into the potentials of a heavy-duty engine running on CNG and equipped with two different injection systems, an advanced single point (SP) one and a prototype multi-point (MP) one. The considered 7.8-liter engine was designed and produced to implement a SP strategy and hence modified to run with a dedicated MP system. A thorough comparison of the engine equipped with the two injection systems has been carried out at steady state as well as at transient operations.
2017-11-27
Technical Paper
2017-01-5022
Sebastian Zirngibl, Stefan Held, Maximilian Prager, Georg Wachtmeister
In order to fulfil future exhaust emission regulations, the variety of subsystems of an internal combustion engine is progressively investigated and optimized in detail. The present article mainly focuses on studies of the flow field and the resulting discharge coefficients of the intake and exhaust valves and ports. In particular, the valves and ports influence the required work for the gas exchange process, as well as the cylinder charge and consequently highly impact the engine‘s performance. For the evaluation of discharge coefficients of a modern combustion engine, a stationary flow test bench has been set up at the Chair of Internal Combustion Engines of the Technical University of Munich. The setup is connected to the test bench’s charge air system, allowing the adjustment and control of the system pressure, as well as the pressure difference across the particular gas exchange valve.
2017-11-27
Technical Paper
2017-01-7012
Brian R. McAuliffe, Mojtaba Ahmadi-Baloutaki
Vehicle-to-vehicle (V2V)-based cooperative heavy-duty-vehicle (HDV) platooning systems are nearing commercialization. One of the major benefits of vehicle platooning is the aerodynamic drag reduction associated with the close coupling of the two vehicles. Various projects on truck platooning have been undertaken in recent years by research groups in North America, Europe, and Japan, many of which have documented road or track testing demonstrating the effect of separation distance on the fuel savings potential of such systems. The fuel savings associated with HDV platooning arises primarily from the aerodynamic interaction of the multiple vehicles, resulting in possible fuel savings for the leading and following vehicles. The aerodynamic benefits will generally be sensitive to the size and location of the low-speed air-wake behind the leading vehicles, and the size and location of the high-pressure zone generated ahead of the trailing vehicles.
2017-11-27
Technical Paper
2017-01-7011
Sandip Phapale, Pavan Sindgikar, Narayan Jadhav
Abstract Indian automotive market has grown extremely competitive in the recent past. In order to meet the ever growing expectations of the customers, automobile manufacturers are compelled to offer their products under superior quality with supreme comfort. Customers wish of high levels of tactile comfort in the cabin compartment and effortless operation of peripherals will result in negligible fatigue and a pleasant drive, needs to be duly fulfilled. One has to focus more on Gear shift lever and Steering wheel, which are being the most sensitive tactile points in an automobile. The gear shift lever knob is frequently used and significantly influences the perception of the shift comfort for a driver during actual vehicle application.
2017-11-20
Technical Paper
2017-01-5021
Greg Suter, Lodewijk Wijffels, Oliver Nehls
This paper will detail the development of a Handling Controller designed to assist the driver in recovering from oversteer situations using an Active Front Steering (AFS) system. The AFS system uses an electric motor to provide a steering angle overlay to the driver’s steering input. This angle can be used to supplement countersteer during an oversteer event, and to rapidly remove countersteer when the sideslip is collapsing, preventing a fishtailing situation. Key factors considered in designing the system were functional safety considerations for potential sensor failures, and how to assist the driver without creating an unnatural feel or excessive torque feedback in the steering wheel. This system may be used to supplement brake stability controls, increasing stability levels with less harshness. The lessons learned from this application may also be used in designing autonomous steering systems to recover from oversteer situations.
2017-11-17
Technical Paper
2017-01-5020
Mark Stuhldreher, Youngki Kim, John Kargul, Andrew Moskalik, Daniel Barba
Abstract As part of its midterm evaluation of the 2022-2025 light-duty greenhouse gas (GHG) standards, the Environmental Protection Agency (EPA) has been acquiring fuel efficiency data from testing of recent engines and vehicles. The benchmarking data are used as inputs to EPA’s Advanced Light Duty Powertrain and Hybrid Analysis (ALPHA) vehicle simulation model created to estimate GHG emissions from light-duty vehicles. For complete powertrain modeling, ALPHA needs both detailed engine fuel consumption maps and transmission efficiency maps. EPA’s National Vehicle and Fuels Emissions Laboratory has previously relied on contractors to provide full characterization of transmission efficiency maps. To add to its benchmarking resources, EPA developed a streamlined more cost-effective in-house method of transmission testing, capable of gathering a dataset sufficient to broadly characterize transmissions within ALPHA.
2017-11-15
Journal Article
2017-32-0120
Go Asai, Yusuke Watanabe, Shuntaro Ishiguro, Gen Shibata, Hideyuki Ogawa, Yoshimitsu Kobashi
To extend the operational range of premixed diesel combustion, fuel reformation by piston induced compression of rich homogeneous air-fuel mixtures was conducted in this study. Reformed gas compositions and chemical processes were first simulated with the chemistry dynamics simulation, CHEMKIN Pro, by changing the intake oxygen content, intake air temperature, and compression ratio. A single cylinder diesel engine was utilized to verify the simulation results. With the simulation and experiments, the characteristics of the reformed gas with respect to the reformer cylinder operating condition were obtained. Further, the thermal decomposition and partial oxidation reaction mechanisms of the fuel in extremely low oxygen concentrations were obtained with the characteristics of the gas production at the various reaction temperatures.
2017-11-15
Journal Article
2017-32-0119
Akira Iijima, Takuya Izako, Takahiro Ishikawa, Takahiro Yamashita, Shuhei Takahata, Hiroki Kudo, Kento Shimizu, Mitsuaki Tanabe, Hideo Shoji
Engine knock is the one of the main issues to be addressed in developing high-efficiency spark-ignition (SI) engines. In order to improve the thermal efficiency of SI engines, it is necessary to develop effective means of suppressing knock. For that purpose, it is necessary to clarify the mechanism generating pressure waves in the end-gas region. This study examined the mechanism producing pressure waves in the end-gas autoignition process during SI engine knock by using an optically accessible engine. Occurrence of local autoignition and its development process to the generation of pressures waves were analyzed under several levels of knock intensity. The results made the following points clear. It was observed that end-gas autoignition seemingly progressed in a manner resembling propagation due to the temperature distribution that naturally formed in the combustion chamber. Stronger knock tended to occur as the apparent propagation speed of autoignition increased.
2017-11-13
Technical Paper
2017-01-5019
Dietmar Fischer, Ger Cronin, Andreas Bock, Ingolf Raschke, Michael Lezuo, Claus Schmitz, David Ruecker, Jenni Herr
One of the functions of a cowl area in a vehicle is the separation of water and air flow. A well working separation of water droplets in the airflow is required under all circumstance, to avoid the blower or air filter to become wet. Airflow calculations help improving the design of the cowl to achieve an effective water droplet separation and simultaneously low pressure losses. The proposed design has been tested under sever conditions. Test results were compared to theoretical results and revised design requirements will be proposed.
2017-11-13
Tech Insights
TI-0002
While all-electric aircraft remain at the bleeding edge of the aviation industry, incorporating technologies like proton exchange membrane fuel cells into existing aircraft can result in considerable auxiliary capability with low environmental impact. However, proper consideration must be given to supporting systems to achieve a reliable balance of plant-especially when those systems interface with existing aircraft architectures. The scope of the BoP is to manage and condition the reactant flows to and from the fuel-cell module and to provide power to system components.
2017-10-31
White Paper
WP-0004
The aerospace industry is facing new challenges to meet burgeoning customer demand. An unprecedented number of orders for commercial aircraft is forcing aerospace manufacturing to make gains in efficiency throughout aircraft production and operation. However, current manufacturing systems are using technologies and production methods unsuited to a future dynamic market. To ensure its profitability, the aerospace industry must seize the opportunity to innovate and readdress approaches to manufacturing. This whitepaper looks at four advanced manufacturing (AM) solutions designed to improve assembly process efficiency, automation, and accuracy.
2017-10-31
White Paper
WP-0003
Actuators are the key to sophisticated machines that can perform complex tasks previously done by humans.
2017-10-25
Technical Paper
2017-01-7009
Genghua Liao, Shaoyun Sun, Kelong Lu, Qiang Fu, Kecheng Pan, Heinz Friz, Bo Li
The implementation of an advanced process for the aerodynamic development of cab-over type heavy trucks at FAW requires a rigorous validation of the tools employed in this process. The final objective of the aerodynamic optimization of a heavy truck is the reduction of the fuel consumption. The aerodynamic drag of a heavy truck contributes up to 50% to the overall resistance and thus fuel consumption. An accurate prediction of the aerodynamic drag under real world driving conditions is therefore very important. The tools used for the aerodynamic development of heavy trucks are wind tunnels and CFD. Wind tunnels have a number of limitations which make it difficult to predict on road performance of the truck. Such limitations are limited availability, blockage and pressure gradient effects, lack of road simulation and Reynolds number effects. While on the other hand CFD does not have such limitations the accuracy of CFD is often questioned and needs to be proven.
2017-10-25
White Paper
WP-0002
The environmental impact of hydrocarbon-burning aircraft, both from the perspective of gas emissions and that of noise, is one of the main motivations for the move to electric propulsion. The added benefit from this shift to electric propulsion is that it has resulted in lowering the costs of electrical components such as motors, power electronic (PE) circuits, and batteries that are essential to this technology. This white paper seeks to explore the history, architecture, electrical components, and future trends of electric flight technology.
2017-10-23
Technical Paper
2017-01-7008
Yoshiharu Inaguma
Abstract This article describes cavitation in a hydraulic disk valve to control an inlet pressure by changing a valve opening at a constant flow rate and an outlet pressure. In the hydraulic system, because the cavitation occurs often and causes an unpleasant noise as well as an instability in pressure-flow control, the cavitation avoidance is important. Hence, for cavitation avoidance under a high pressure condition, the influences of the specifications of the disk and nozzle as well as operating conditions on the cavitation and the inlet pressure change against the valve opening are experimentally investigated. Under a constant flow rate and an outlet pressure, the inlet pressure rises and the cavitation appears when the valve opening decreases. By decreasing the valve opening more, however, the cavitation disappears despite a rise in the inlet pressure. In addition, the round edge at the nozzle outlet is effective in avoiding the cavitation.
2017-10-16
Technical Paper
2017-01-7007
Hardik Lakhlani
Abstract Turbocharging has become an important method for increasing the power output of diesel engines. A perfectly matched turbocharger can increase the engine efficiency and decrease the BSFC. For turbocharger matching, engine manufacturers are dependent on the turbocharger manufacturers. In this paper, an analytical model is presented which could help engine manufacturers to analyze the performance of turbocharger for different load and ambient condition using compressor and turbine map provided by turbo manufacturers. The analytical model calculates the required pressure at inlet and exhaust manifold for fixed vane turbocharger with waste gate using inputs like BSFC, lambda, volumetric efficiency, turbocharger efficiency and heat loss, that are available with the engine manufacturer.
2017-10-13
Technical Paper
2017-01-5015
Samuel Joseph Reinsel, Douglas Nelson
The purpose of this research is to refine the shifting behavior and drivability of a post transmission (P3) plug-in parallel hybrid electric vehicle (PHEV) being developed by the Hybrid Electric Vehicle Team (HEVT) for the EcoCAR3 competition. The vehicle’s powertrain has been modified with an electric motor placed on the driveshaft after the conventional 8 speed automatic transmission. This motor can be leveraged to smooth out the jerk experienced by the driver during part-load transmission shifts, as well as other drivability metrics such as gearshifts and cruise control. These metrics also include powered take off, tip in, and tip out events. Additionally, improving the drivability of active fuel management (AFM or cylinder deactivation) mode by assisting the engine will be examined to attempt to improve drivability.
2017-10-13
Technical Paper
2017-01-5012
Harveer Singh Pali, Shashi Prakash Dwivedi
Abstract The present work deals with the fabrication and tribological testing of an aluminium/SiC composite. Fabrication was done using two techniques; mechanical stir casting and electromagnetic stir casting. Metal matrix composite (MMC) was fabricated using aluminium as a matrix and SiC as reinforcement in varying weight percentages. The wear and frictional properties of the MMC were studied by performing dry sliding wear test using a pin-on-disc wear tester for both types of samples. Wear rate retards with the increase the percentage of reinforcement whereas it improves with the addition of normal force. At same time frictional coefficient upsurges by increasing the normal force and percentage of reinforcement. Increasing percentage of reinforcement and using electromagnetic stir casting process obtained the higher frictional coefficient and lower wear rate.
2017-10-13
Technical Paper
2017-01-5014
Maurilio Pereira Gomes, Igor Santos, Camila Couto, Cristiano Mucsi, Jesualdo Luiz Rossi, Marco Colosio
Abstract This work consists of evaluating the influence of heat treatment on sintered valve seat insert (VSI) obtained with two different high-speed steels powders and one tool steel: AISI M3:2, AISI M2 and AISI D2, respectively. The high-speed / tool steel powders were mixed with iron powders and additives such as manganese sulphide, zinc stearate, graphite and niobium carbide. All the high-speed / tool steel powders had its particle size distribution and morphology analyzed. The heat treatment of the VSI consisted of air quenching followed by double tempering it in seven different and equidistant temperatures, ranging from 100 °C until 700 °C. A data acquisition system with a thermocouple type k attached to the samples was used to determine the air-quenching cooling rate. The mechanical and physical properties measurements were carried out, i.e., apparent density, apparent hardness and crush radial strength.
2017-10-13
Technical Paper
2017-01-5013
G. Magendran
The input shafts are conventionally developed through Hot forging route. Considering upcoming new technologies the same part was developed through cold forging route which resulting in better Mechanical properties than existing hot forging process. It has added benefit of cost as well as environmental friendly. Generally, the part like Input shaft which having gear teeth, splines etc., will be manufactured through Hot forging process due to degree of deformation, availability of press capacity, diameter variations etc., This process consumes more energy in terms of electricity for heating the bar and also creates pollution to the atmosphere. Automotive input shaft design modified to accommodate cold forging process route to develop the shaft with press capacity of 2500T which gives considerable benefit in terms of mechanical and metallurgical Properties, close dimensional tolerances, less machining time, higher material yield when compared to hot forging and metal cutting operation.
2017-10-13
Technical Paper
2017-01-5018
Subhash Hanmant Bhosale, Manohar Goud Kalal, Ashish Kumar Sahu
Abstract In today’s cost-competitive automotive market, use of finite element simulations and optimization tools has become crucial to deliver durable and reliable products. Simulation driven design is the key to reduce number of physical prototypes, design iterations, cost and time to market. However, simulation driven design optimization tools have struggled to find global acceptance and are typically underutilized in many applications; especially in situations where the algorithms have to compete with existing know-how decision making processes. In this study, systematic multi-phase approach for optimization driven design is presented. Approach includes three optimization phases. In first phase, topology optimization is performed on concept BIW design volume to identify critical load paths. Architectural inputs from topology are used to design base CAD.
2017-10-13
Technical Paper
2017-01-5017
Ronith Stanly, Gopakumar Parameswaran, R Rajkiran
Abstract Conventionally, influence of injector coking deposits has been studied using accelerated coking methods. For this work we used in-use vehicles fitted with Common Rail Direct injection (CRDi) injectors in “as-is where is” condition with considerable coked injector deposits. They were then cleaned with a commercial fuel system cleaning solution which did not require the removal of injectors; the influence of injector deposits on vehicular performance and spray field were studied. It was observed that the removal of coking deposits resulted in an increase in the peak power of the vehicle, a lower fuel injected quantity and lower fuel injection duration. It was also observed that the fuel system cleaning procedure resulted in better atomization of fuel spray, better uniformity of the multiple spray jets and an increase in the flow rate of the test injectors.
2017-10-13
Technical Paper
2017-01-5016
Apoorva Tyagi, N. Madhwesh
Abstract With the advancements of trends in Formula1 it has been quite clear that aerodynamics plays one of the most vital roles in the performance of the car. A typical aerodynamic package of a Formula1 car consists of rear wings, front wings and an under tray diffuser. This research paper is concerned with the development of an efficient under tray diffuser. The under tray diffuser is a shaped section of the car underbody to improve the aerodynamic properties of the car. Mainly it is used to generate maximum down force corresponding to minimum drag. Several studies have been carried out in recent decades to improve the vehicle performance, aerodynamic properties in particular. The present work deals with studying the performance of under tray diffuser by varying the geometric properties of the under tray diffuser such as Inlet angle, Outlet angle corresponding to varying ground clearances.
2017-10-13
Technical Paper
2017-01-7006
Gao Ke, Zhao Weiqiang, Zhimin Ma
As the main passenger and freight transport equipment,commercial vehicle’s safety and comfort has become particularly important.Due to the long traveled distance,commercial vehicle is equipped with more than one driver.Different drivers have their unique steering behavior and same driver have a large physical power change when driving for a long time.Therefore,the needs of drivers cannot be met by a single model of the steering characteristics.If the vehicle steering characteristics are not suitable for the drivers,the vehicle will always produce too much/ little of the steering angle when driver controls steering system.The steering angle need to be adjusted again by driver when this happens.The occurrence of such a situation will affect the road safety, and cause extra burden on driver. On the basis of the traditional hydraulic power, dynamic steering system adds an electric servo motor to the steering column.
2017-10-13
Technical Paper
2017-01-7005
Lijuan Wang, Jeffrey Gonder, Eric Wood, Adam Ragatz
Abstract Fuel consumption (FC) has always been an important factor in vehicle cost. With the advent of electronically controlled engines, the controller area network (CAN) broadcasts information about engine and vehicle performance, including fuel use. However, the accuracy of the FC estimates is uncertain. In this study, the researchers first compared CAN-broadcasted FC against physically measured fuel use for three different types of trucks, which revealed the inaccuracies of CAN-broadcast fueling estimates. To match precise gravimetric fuel-scale measurements, polynomial models were developed to correct the CAN-broadcasted FC. Lastly, the robustness testing of the correction models was performed. The training cycles in this section included a variety of drive characteristics, such as high speed, acceleration, idling, and deceleration. The mean relative differences were reduced noticeably.
2017-10-12
White Paper
WP-0005
Annie Chang, Nicolas Saunier, Aliaksei Laureshyn
To date, the universal metric for road safety has been historical crash data, specifically, crash frequency and severity, which are direct measures of safety. However, there are well-recognized shortcomings of the crash-based approach; its greatest drawback being that it is reactive and requires long observational periods. Surrogate measures of safety, which encompass measures of safety that do not rely on crash data, have been proposed as a proactive approach to road safety analysis. This white paper provides an overview of the concept and evolution of surrogate measures of safety, as well as the emerging and future methods and measures. This is followed by the identification of the standards needs in this discipline as well as the scope of SAE’s Surrogate Measures of Safety Committee.
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