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Viewing 1 to 30 of 85310
2018-01-19
Technical Paper
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.
2018-01-19
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.
2018-01-12
Journal Article
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.
2017-10-31
White Paper
WP-0003
Actuators are the key to sophisticated machines that can perform complex tasks previously done by humans.
2017-10-23
Technical Paper
2017-01-7008
Yoshiharu Inaguma
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 outlet pressure. A disk valve, which has a fundamental configuration of a poppet valve, is widely used in a hydraulic system such a power steering system in order to control flow and pressure in the system. The disk valve, which makes a large flow area with a small valve opening, has a simple construction and does not reqire its parts to be machined with severe torelances. The disk valve with a diverging flow, however, is apt to cause cavitation because the inlet pressure becomes lower than the outlet pressure in a gap between the nozzle seat and the disk. The cavitation affects the pressure control performance and thrust force and causes an unpleasant noise. Hence, the cavitation is a very important problem because the hydraulic system is used recently under a high pressure condition.
2017-10-16
Technical Paper
2017-01-7007
Hardik Lakhlani
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
2017-01-7005
Lijuan Wang, Jeffrey Gonder, Eric Wood, Adam Ragatz
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 measurement, 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.
2017-10-13
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.
2017-10-12
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.
2017-10-08
Technical Paper
2017-01-2335
Tiantian Yang, Tie Wang, Jing Qiao, Ji Gao, Yizhuo Feng, Dandan Sun
Abstract The F-T diesel made from coal by Fischer-Tropsch synthesis (F-T) can be used as a clean alternative fuel of diesel engine. To alleviate the drawback of high cost and low viscosity of F-T diesel, the Methanol-Biodiesel -F-T diesel multiple fuel (MBFT) was prepared by adding low-cost methanol and high-viscosity biodiesel as modifiers. Considering the immiscibility between alcohols and hydrocarbons, this paper carried out a series of stability tests and found that n-decanol was the optimum co-solvent of MBFT. The MBFTs blended by biodiesel with the volume fraction of 10% (10% vol.) and methanol with varying proportions of 0%, 5%, 10% and 15% vol. were denoted as M0, M5, M10 and M15, respectively. The increasing methanol proportion caused the increase of the oxygen content in the blended fuels and the reduction of heat value, surface tension and cetane number. The influence of methanol proportion on combustion characteristics of turbo-charging engine was studied.
2017-10-08
Technical Paper
2017-01-2332
Tamara Ottenwaelder, Stefan Pischinger
Abstract In order to reduce engine out CO2 emissions it is a main subject to find new alternative fuels out of renewable sources. For this paper, several fuels were selected which can be produced out of biomass or with hydrogen which is generated directly via electrolysis with electricity from renewable sources. All fuels are compared to conventional diesel fuel and two diesel surrogates. It is well known that there can be a large effect of fuel properties on mixture formation and combustion, which may result in a completely different engine performance compared to the operation with conventional diesel fuels. Mixture formation and ignition behavior can also largely affect the pollutant formation. The knowledge of the combustion behavior is also important to design new engine geometries or implement new calibrations for an existing engine. The fuel properties of the investigated fuels comprise a large range, for example in case of the derived cetane number, from below 30 up to 100.
2017-10-08
Technical Paper
2017-01-2330
Leonardo Israel Farfan-Cabrera, Ezequiel Gallardo, José Pérez-González
Abstract Flouroelastomers and silicone rubbers are commonly employed in static and dynamic seals for automotive applications. In order to prevent premature failures and leakages caused by swelling and/or changes in their mechanical properties, materials for seals are selected according to their compatibility with the environment and fluids involved in the engine operation. Thus, in particular, the use of new fuels and additives in automotive engines requires the assessment of compatibility with common sealing elastomers to prevent failures. Currently, Jatropha oil is being used as a renewable source of fuel in diesel engines for electricity production, transport or agricultural mechanization in various countries. It is used either as biodiesel or as straight vegetable oil (SVO) since it has good heating power and provide exhaust gas with almost no sulfur or aromatic polycyclic compounds. However, the compatibility of elastomers with this SVO has not been investigated yet.
2017-10-08
Technical Paper
2017-01-2331
Amar Deep, Naveen Kumar, Harveer Singh Pali
Abstract The use of alternative fuel has many advantages and the main ones are its renewability, biodegradability with better quality exhaust gas emission, which do not contribute to raise the level of carbon dioxide in the atmosphere. The use of non-edible vegetables oils as an alternative fuels for diesel engine is accelerated by the energy crisis due to depletion of resources and increase in environmental problems. In Asian countries like India, great need of edible oil as a food so cannot use these oils as alternative fuels for diesel engine. However there are many issues related to the use of vegetable oils in diesel engine that is high viscosity, low calorific value, high self-ignition temperature etc. Jatropha curcas has been promoted in India as a sustainable substitute to diesel fuel. This research prepared micro emulsions of ethanol and Jatropha vegetable oil in different ratio and find out the physico-chemical parameters to compare with mineral diesel oil.
2017-10-08
Technical Paper
2017-01-2351
Bernardo Tormos, Guillermo Miró, Leonardo Ramirez, Tomás Pérez
Abstract Low viscosity engine oils are considered a feasible solution for improving fuel economy in internal combustion engines (ICE). So, the aim of this study was to verify experimentally the performance of low viscosity engine oils regarding their degradation process and possible related engine wear, since the use of low viscosity engine oils could imply higher degradation rates and/or unwanted wear performance. Potential higher wear could result in a reduction in life cycle for the ICE, and higher degradation rates would be translated in a reduction of the oil drain period, both of them non-desired effects. In addition, currently limited data are available regarding “real-world” performance of low viscosity engine oils in a real service fleet.
2017-10-08
Technical Paper
2017-01-2352
Gongde Liu, Li Wang, Runxiang Zhang, Chao Yang, Tengfei Shao
Abstract Fuel economy, Emission regulation and extended oil drain intervals (ODI) are the three key driving forces for engine oil development. More and more attentions have been focused on long ODI diesel engine oil both from the domestic OEMs and oil suppliers, and the ODI was being periodically improved from a normal mileage of about 1×104 kilometers to 6/8/10×104 km or even 12×104 km just within several years on China market. Lots and lots of factors may affect the oil life including oil properties, engine technologies, after-treatment devices and engine working conditions and so on. While from the oil side, the main factors contribute to the oil drain intervals may be the oil nitration and oxidation, soot contamination, base number deterioration and sludge accumulation and etc. There are two strategies to extend the oil longevity applied currently.
2017-10-08
Technical Paper
2017-01-2353
Bernardo Tormos, Leonardo Ramirez, Guillermo Miró, Tomás Pérez
Abstract One of the most interesting alternatives to reduce friction losses in the internal combustion engines is the use of low viscosity engine oils. Recently, a new engine oil category focused fuel economy, has been released in North America encouraging the use of these oils in the heavy-duty vehicles’ segment. This paper presents the results of a comparative test where the differences in fuel consumption given by the use of these oils are shown. The test included 48 buses of the urban public fleet of the city of Valencia, Spain. The selected vehicles were of four different bus models, three of them fueled with diesel and the other one with compressed natural gas (CNG). Buses’ fuel consumption was calculated on a daily basis from refueling and GPS mileage. After three oil drain intervals (ODI), the buses using low viscosity engine oils presented a noticeable fuel consumption reduction. These results bear out the suitability of these oils to palliate engine inefficiencies.
2017-10-08
Technical Paper
2017-01-2354
Dave Horstman, John Sparrow
Abstract Due to recent legislation on CO2 emissions, Heavy Duty engine and vehicle manufacturers and their suppliers have had an increased interest in improving vehicle fuel economy. Many aspects are being investigated including vehicle aerodynamics, tire rolling resistance, waste heat recovery, engine fuel efficiency, and others. Crankcase oils offer a cost-effective mechanism to reduce engine friction and increase engine fuel efficiency. The potential gains realized by optimized fuel-efficient oils are relatively small, usually less than 3%. Therefore, in order to develop these oils, formulators must have a robust, repeatable, and realistic test method for differentiation. To serve Light Duty (LD) engines, this need has been partially satisfied by the development of what became the Sequence VI engine test for gasoline passenger car oils in the early 1990’s.
2017-10-08
Technical Paper
2017-01-2347
Kazushi Tamura, Kenji Sunahara, Motoharu Ishikawa, Masashi Mizukami, Kazue Kurihara
Abstract Modern formulation in a wide variety of lubricants including engine oils and transmission fluids is designed to control friction through film-forming tribochemical reactions induced by the functional additives mixtures. Although many cases on the synergistic or antagonistic effects of additives on friction have been reported, their mechanisms are poorly understood. This study focused on the influences of metallic detergents on tribochemical reactions. We examined the mechanical properties of detergent-containing lubricants confined at a single-asperity contact and their contributions to tribochemical phenomena. We found that detergents enlarged the confinement space required for generating repulsive force and shear resistance. This means that these detergents provide steric effects under nanoconfinement at interfacial contacts.
2017-10-08
Technical Paper
2017-01-2349
Sarita Seth, Swamy Maloth, Prashant Kumar, Bhuvenesh Tyagi, Lokesh Kumar, Rajendra Mahapatra, Sarita Garg, Deepak Saxena, R Suresh, SSV Ramakumar
Abstract Automobile OEMs are looking for improving fuel economy[1,2] of their vehicles by reducing weight, rolling resistance and improving engine and transmission efficiency apart from the aerodynamic design. Fuel economy may be improved by using appropriate low viscosity [3] and use of friction reducers (FRs)[4,5] in the engine oils. The concept of high viscosity index [6] is being used for achieving right viscosity at required operating temperatures. In this paper performance properties of High Viscosity Index engine oils have been compared with conventional VI engine oils. Efforts have been made to check the key differentiation in oil properties w.r.t. low temperature fluidity, high temperature high shear viscosity/deposits, friction behavior, oxidation performance in bench tribological /engine/chassis dyno tests which finally lead to oil performance assessment.
2017-10-08
Technical Paper
2017-01-2350
Chalermwut Wongtaewan, Umaporn Wongjareonpanit, Komkrit Sivara, Ken Hashimoto, Yoichiro Nakamura
Abstract In Thailand, most heavy-duty trucks were equipped with diesel engine, while a small portion was equipped with compressed natural gas (CNG) engine. However, in the past few years the number of CNG fuel trucks in Thailand has increased significantly due to the cheaper cost of CNG. In general, the emphasis of heavy-duty diesel engine oil performance is on piston cleanliness and soot handling properties, while thermal and anti-oxidation properties are most critical for CNG engine oil performance. For truck fleet owners who operate both types of trucks, using the inappropriate oil that is not fit-for-purpose can adversely affect engine performance and reduce engine service lifespan under prolonged usage. A novel CNG/diesel engine oil was developed to meet both JASO DH-2 heavy-duty diesel engine oil performance and CNG engine oil performance. The candidate formulation was proved adequately fit for practical use regarding to thermal and anti-oxidation properties.
2017-10-08
Technical Paper
2017-01-2344
Robert Taylor, Hua Hu, Carl Stow, Tony Davenport, Robert Mainwaring, Scott Rappaport, Sarah Remmert
Abstract It is anticipated that worldwide energy demand will approximately double by 2050, whilst at the same time, CO2 emissions need to be halved. Therefore, there is increasing pressure to improve the efficiency of all machines, with great focus on improving the fuel efficiency of passenger cars. The use of downsized, boosted, gasoline engines, can lead to exceptional fuel economy, and on a well-to-wheels basis, can give similar CO2 emissions to electric vehicles (depending, of course, on how the electricity is generated). In this paper, the development of a low weight concept car is reported. The car is equipped with a three-cylinder 0.66 litre gasoline engine, and has achieved over 100 miles per imperial gallon, in real world driving conditions.
2017-10-08
Technical Paper
2017-01-2338
Muhammad Saqib Akhtar, Shuaishuai Sun, Xiao Ma, Yitao Shen, Shi-Jin Shuai, Zhi Wang
Abstract Natural gas is one of the promising alternative fuels due to the low cost, worldwide availability, high knock resistance and low carbon content. Ignition quality is a key factor influencing the combustion performance in natural gas engines. In this study, the effect of pre-chamber geometry on the ignition process and flame propagation was studied under varied initial mixture temperatures and equivalence ratios. The pre-chambers with orifices in different shapes (circular and slit) were investigated. Schlieren method was adopted to acquire the flame propagation. The results show that under the same cross-section area, the slit pre-chamber can accelerate the flame propagation in the early stages. In the most of the cases, the penetration length of the flame jet and flame area development are higher in the early stages of combustion.
Viewing 1 to 30 of 85310