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Viewing 91 to 120 of 10136
2015-04-14
Technical Paper
2015-01-1524
Ping Chen, Nan Xu, Konghui Guo, Rongsheng Liu
Tire lateral force is essential to vehicle handling and stability under cornering. However, it is difficult for engineers to get tire lateral force under high loading condition due to the loading ability limitation of most tire test machine in the world. Widely used semi-empirical tire lateral force models are obtained by curve-fitting experiments data and don’t possess load prediction ability. The objective of this paper is to predict the tire lateral force model under high-load condition based on low-load tire data. The nonlinear characteristic of tire cornering stiffness vary with load is greatly affected by tire carcass compliance. In this paper, a theoretical tire lateral model was built by considering carcass complex deformation. Combined with the relationship between half-length of tire contact patch and load, the non-linear characteristic of tire cornering stiffness vary with load was obtained.
2015-04-14
Technical Paper
2015-01-1554
Bastian Schnepf, Thomas Schütz, Thomas Indinger
Efforts in aerodynamic optimization of road vehicles have been steadily increasing in recent years, mainly focusing on the reduction of aerodynamic drag. This has been motivated by the need of reducing CO2 emissions as well as extending the range of electric vehicle concepts. Both targets can only be achieved when all driving resistances are minimized. At velocities higher than 70 kph aerodynamic drag, which increases with the square of velocity, even becomes the dominant force. Breaking a passenger car’s aerodynamic drag down into the contributions of certain areas, wheels and wheel houses account for approx. 25 percent [1], a large share compared to their geometric dimensions. Consequently, industry and academia have been investigating the flow around automotive wheels intensively at an increasing level of detail lately.
2015-04-14
Technical Paper
2015-01-0624
Mustafa Arat, Emmanuel O. Bolarinwa
The increasing demand of energy use in transportation systems combined with the limited supply of fossil hydrocarbons to support conventional engines has led to a strong resurgence in interest for electric vehicles (EVs). Although EVs offer the possibility of decoupling the issue of energy source from the primary torque generator in an automobile, the current technology is yet to match the well-developed internal combustion (IC) systems, especially in terms of energy capacity and travel range. In this study, the influence of rolling-resistance on the energy efficiency and road holding of electric vehicles is described. Rolling resistance is taken in the context of energy loss (e.g. the mechanical energy converted into other sources of energy) for a unit distance traveled by the tire.
2015-04-14
Technical Paper
2015-01-0724
Liangxu Ma, Liangyao Yu, Jian Song, Xuhui Liu, WenWei Xuan
Magneto-rheological (MR) fluid is a novel composite material and can be used in different components of vehicle. Magneto-rheological fluids (MRF) are suspensions of micron sized whose yield stress varies rapidly as the change of magnetic field applied. The use of magneto-rheological (MR) fluids in vehicles has been gaining popular recently due to its strong rheological effect, fast response, good stability and low energy consumption, which give automotive designers more dimensions of freedom in functional designs. Nowadays, most of the related research of MRF is about the construction of the prototype and the realization of the brake force. However, due to a lack of optimal design and the understanding of MRF and magnetic field, the main research progress is only about the simulation which makes the braking effect of the prototype can hardly meet the requirement of vehicle.
2015-03-30
Technical Paper
2015-01-0101
Piyapong Premvaranon, Jenwit Soparat, Apichart Teralapsuwan, Wuttipong Sritham, Chi-na Benyajati, Nathapol Taweewong
Due to recent oil price crisis and an ever-increasing public awareness on environmental issues, an interest in electric vehicles (EV) has increased tremendously in Thailand and other Asian countries over the last few years. In this study, a prototype of 9-metre battery electric vehicle (BEV) bus was chosen as a vehicle of interest to undergo a series of field test by operating the lead acid battery powered electric bus in order to estimate a power demand of the bus as well as to evaluate a battery performance characteristic Two different types of battery were employed in this study i.e. a flooded-type deep cycle lead acid battery and a valve regulated lead acid (VRLA) battery. The effect of different driving modes available from the drive motor i.e. normal, max power, max range, as well as regenerative braking feature would be investigated while an influence of drivers were also taken into account to ensure the repeatability of the obtained results.
2015-03-30
Technical Paper
2015-01-0090
Cherdsak Chuaymung, Chi-na Benyajati, Sutee Olarnrithinun
A vehicle of interest in this paper was a light agriculture truck operated by a 14 hp single cylinder engine. Its chassis type is a ladder frame with Hotchkiss setup suspension. In Thailand this particular truck is also called E-TAN and is mostly driven on rough terrains under agricultural applications. To improve the current design, the information on a structural strength of the truck frame is required. A combination of physical tests and computer simulations was arranged to obtain reliable predictions of stress generated in the frame under load. For the simulations, a Computer Aided Design (CAD) model of the ladder frame included a main frame and a sub frame, on which an engine and transmission system would be mounted. Leaf spring mounting brackets were modeled as well as shock absorbers mounting structures. A completed Finite Element (FE) model of the frame contains 29,730 quadratic shell elements and 34,055 nodes.
2015-03-30
Technical Paper
2015-01-0082
Husain Kanchwala, Carlos Bordons
Electric vehicles (EVs) have been gaining a lot of focus and attention as they run clean and are environment friendly. EVs use in-hub motors, which can be independently controlled, improving this way the maneuverability and allowing augmented control actions. This paper discusses the development of a Model Predictive Controller (MPC) to improve vehicle handling characteristics. Wheel torques are independently controlled using direct yaw moment and side slip control method to pro-actively improve vehicle handling. At high values of side slip the steering is no more capable of generating yaw moment and vehicle becomes laterally unstable. By unequal torque distribution a restoring yaw moment is generated and vehicle stability is ensured. The MPC computes the optimal couple traction/braking torque of the four in-wheel motors, from basic driving slogans, which are, steering angle and desired speed.
2015-03-30
Technical Paper
2015-01-0081
Chunguang Duan, Hsin Guan, Pingping Lu
With the development of computer and vehicle research to high frequency, the driving simulator plays an important role on vehicle research and pre-development. The driving simulator have already used for research about human factor, advanced active system (ABS, ESP et al), the vehicle engineering, intelligent transportation system (ITS) et al. The requirements for a driving simulator are that it should have realistic behavior. One aspect of the realistic behavior is that the driving simulator needs to be able to stop and to start again. The realistic behavior base on high-fidelity dynamic models especially tire model. “Tire/road” model is of special importance model for its influence on vehicle simulation results. The forces for accelerating, braking and steering are all come from tire road contact. The simulator simulation faces all possible driving situations as driving the real vehicle, like parking on the hill, stop and start again, sharp steering, sharp braking et al.
2015-03-10
Technical Paper
2015-01-0053
Rakesh Khanger, Amritashu Bardhan
Abstract Vehicles in India will soon come with star ratings, signifying how environment-friendly they are. The OEM's have braced to improve fuel economy of their existing & upcoming models. Tire rolling resistance is one of the significant factors for vehicle fuel consumption. Improvement in Fuel consumption is always a prime focus area & to improve it all majors are considered. In newly launched models, the low rolling resistance tire development was initiated. The project is challenging as it requires not only achieving low rolling resistance but also other critical vehicle performance parameters like ride, handling, NVH & durability. Effects of Tire construction, rubber compound were analyzed to achieve lower rolling resistance and better durability of tire. In addition, the factors affecting the rolling resistance of tire like inflation pressure, load, and speed are discussed in this paper.
2015-03-10
Technical Paper
2015-01-0042
Yimingo Alan, wwwxinwww Wang
To get the same ride comfort under empty load as full load condition, a two-level variable stiffness spring was used to be as the rear suspension of a light bus. The contact load , which is the load acted on the spring when the second-level stiffness of the spring begins to work, is one of the key factors for affectting the NVH performance of the bus. This paper presented one calculation method of the contact load. In the proposed method, the dynamic load of the suspension was mainly considered, which relates to the unspring mass, the road grade and the commonly driving speed. A semiempirical formula of the contact load was put forward. Then the contact load of the commercial bus’s rear suspension was respectively calculated by using the proposed formula and traditional method(geometric mean method and average load method) to compare each other and to verify the new method. Next the samples of the rear suspension were respectively manufactured based on the result.
2015-03-10
Technical Paper
2015-01-0044
Yuto Fukumori, Ryuzo Hayashi, Ryosuke Matsumi, Yoshihiro Suda, Kimihiko Nakano
Ride comfort and drivability of automobiles depends on suspension systems. In order to improve these performances, various methods for motion control with a single suspension system and coupled suspension system have been proposed. The existing methods use hydraulic dampers generally. However, it is not easy to couple hydraulic dampers because it requires designing and manufacturing complex pipelines.Recently, the authors proposed an electromagnetic dampers as a component of next-generation suspension system aiming at improving responsiveness, controllability, and energy saving performance. The electromagnetic damper is composed of an electric motor, a ball screw, and a nut so that it can convert kinetic energy to electrical energy. The opposite conversion is also available.Then, the electromagnetic damper has two remarkable characteristics.
2015-01-30
Article
Freescale Semiconductor’s FXTH87 tire-pressure monitoring system family provides low-power consumption and functional integration in a compact package.
2015-01-23
WIP Standard
ARP4834B
This SAE Aerospace Recommended Practice (ARP) sets forth criteria for the selection, inspection, retread and repair of worn civil aircraft tires, and the means to verify that the retreaded tire is suitable for continued service. This document is applicable to both bias ply and radial aircraft tires qualified subsequent to the adoption of this document.
2015-01-22
WIP Standard
J2975
This procedure describes a method for generating, preparing and analyzing samples of new and unused brake friction materials for their chemical constituents.
2015-01-15
WIP Standard
J1095
This SAE Recommended Practice provides uniform laboratory procedures for fatigue testing of spoke wheels and hubs intended for normal highway use on trucks, buses, truck trailers, and multipurpose passenger vehicles. The hubs included have bolt circle diameters from 165.1 to 335.0 mm (6.50 to 13.19 in). It is up to each hub and/or spoke wheel developer to determine what test method, accelerated load factor and cycle life requirements are applicable to obtain satisfactory service life in a given application. When deviations from the procedures recommended herein are made, it is the responsibility of the hub and/or spoke wheel developer to modify other parameters to obtain satisfactory service life.
2015-01-14
Article
Car put on display is based on electrical and mechanical components from a Renault electric vehicle "city car" simply as a proof of process. Much testing and refinement remain. Help is being provided by Oak Ridge National Laboratory and SABIC.
2015-01-14
Technical Paper
2015-26-0007
Medha Santosh Jambhale, J Kale, Mangesh Ramesh Saraf, Arunrajkumar Govindhasamy, Karl-Eric Köstlin
Abstract A vehicle's suspension system is the basic component which decides its dynamic performance. It is designed to separate the vehicle body and its passengers or payload from vibrations arising due to road disturbances, at the same time to ensure that the tires stay in adequate contact with the road surface. Challenges in suspension design many a time's leads in a compromise between the conflicting demands of ride comfort and road holding. Vehicles having soft suspension isolate the vehicle body from the higher frequencies in suspension but reduce the ability of the dampers to control the wheel movements which leads to poor road holding. Conversely, hard suspension provides more road holding but transmits more of the suspension movement to the body; in turn provide a less comfortable ride. The development of active/ semi active suspension has addressed both these needs and provides optimum level of ride comfort and road holding which results in the safety and driving pleasure.
2015-01-14
Technical Paper
2015-26-0004
Jitendra Shah
Abstract A first step towards autonomous rear-end collision avoidance is to start providing natural support to driver in avoiding collision by steering and braking intervention. The proposed system detects slower-moving and stationary vehicles ahead and classifies the risk of having a rear-end-collision. If the risk is high and there is insufficient space to avoid a collision by braking only, the system helps the driver to steer around the obstacle by steering rear toe angle of the wheels individually. A lot of research already exist in the rear wheel steering but the role of rear wheel steering in collision avoidance is not researched yet in great details. Rear wheel steering is used to increase agility and manoeuvrability of vehicle at lower vehicle speed and stability of vehicle at higher vehicle speed.
2015-01-14
Technical Paper
2015-26-0062
Pankaj Kumar Verma, Shashi Bhushan Singh, Kalyan Vedula
Abstract The Armoured fighting vehicle designers are continuously fighting for ways to reduce vehicle weight, increase fuel efficiency, improve reliability, and reduce cost. Customized engineering design and materials are becoming more widespread on all fronts. Also, vehicle emission norms are getting stringent day by day and there is increasing pressure to reduce fuel consumption. One important method of achieving the fuel economy and improve vehicle performance is to reduce vehicle weight. In view of the above advanced materials like Carbon Fiber Reinforced Polymer (CFRP) composites are promising to be the material to look for when it comes to reduce weight of structural elements due to its high strength to weight and high stiffness to weight ratios and hence was used for the development of Bogie Wheel of a light tracked vehicle. This paper illustrates the developmental methodology of Carbon Fiber Reinforced Polymer (CFRP) Road wheel for 20 ton class of tracked vehicle.
2015-01-14
Technical Paper
2015-26-0059
Rahul R Kartha, Mohammad Jamadar, Kishor Kumar Kavathekar, S D Rairikar, S. S Ramdasi, S.S Thipse, N. V Marathe
Abstract The paper deals with the simulation of a Light Commercial Vehicle (LCV) using vehicle performance algorithms. This method speeds up the product development process. Also by using these kind of methodology in vehicle simulation there is much noticeable reduction in cost of testing. The simulation model is used for parametric studies of the vehicle and also to attain objectives such as to optimize transmission ratio, full load acceleration, maximum tractive force, gradient performance, fuel consumption and the exhaust emission. In this case study, simulation model of a CNG, LCV is used to analyze the performances similar to that done in a chassis dynamometer. The simulation leads to the prediction and evaluation of various parameters such as fuel consumption, exhaust emissions, full load acceleration, gradient performance & maximum tractive effort for Indian Driving Cycle.
2015-01-14
Technical Paper
2015-26-0068
Muthuraj Ramasamy, Vignesh E, Sundararajan Thiyagarajan
Abstract A “WHEEL” is one of those auto component in a vehicle which necessitates equal attention from safety, ergonomics and aesthetic perspectives. A conventional tube type wheel for commercial vehicles is made of steel with steel side rings (multi-piece construction). In course as headway in wheel design the single piece wheels were developed which used the tubeless tires. These wheels were made available in both steel and aluminum versions. Wherein the aluminum wheels were lighter in weight than steel, aesthetically more appealing and had other significant advantages. Despite the advantages of these tubeless tire wheels, the end user had to invest for both wheels and tubeless tires to replace conventional tube type steel wheels. The retro-fitment calls for higher exchange cost of wheel and tire and this process stands to be more capitalistic to the end user wherein the payback period was longer.
2015-01-14
Technical Paper
2015-26-0084
Ishwar Patil, Kiran P Wani
Abstract The three main objectives that a suspension system of an automobile must satisfy are ride comfort, vehicle handling and suspension working space. The aim of this paper is to design and analyze the semi active suspension system models using skyhook, ground hook and hybrid control method. The two degree of freedom (2 DOF) quarter car model is used for analysis of vehicle body displacement, vehicle acceleration and suspension working space and dynamic tire deflection. Simulation of semi active control models are carried out in MATLAB SIMULINK which describes performance of passive system, skyhook on-off and continuous control, ground hook control and hybrid control methods. Time response analysis shows that, for road bump excitation of 70mm vertical displacement, skyhook on-off control improves ride comfort for the results of maximum peak to peak body displacement with 27.53% improvement than that of the passive suspension model.
2015-01-14
Technical Paper
2015-26-0082
Jeevan N. Patil, Sivakumar Palanivelu, Vaibhav Aswar, Vipin Sharma
Abstract Pneumatic brake system is widely used in heavy truck, medium and heavy buses for its great superiority and braking performance over other brake systems. Pneumatic brake system consists of various valves such as Dual Brake Valve (DBV), Quick release Valve (QRV), Relay Valve (RV), Brake chambers. Dynamics of each valve is playing a crucial role in overall dynamic performance of the braking system. However, it is very difficult to find the contribution of each valve and pipe diameters in overall braking performance. Hence, it is very difficult to arrive a best combination for targeted braking performance as it is not possible to evaluate all combination on the actual vehicle. Hence, it is very important to have a mathematical model to optimize and evaluate the overall braking performance in early design phase. The present study is focusing on the mathematical model of a pneumatic brake circuit.
2015-01-14
Technical Paper
2015-26-0086
Prakhar Srivastava, Manish Laxman Karle, Ujjwala Shailesh Karle, Anand A Deshpande
Abstract Electric Power Assist Steering (EPAS) is a safety critical system because it affects vehicle stability and dynamics. In EPAS, electric motor takes the power from the battery and delivers this power to rack and pinion only on demand. Since EPAS contains electrical component such as Motor and electronic component such as Electronic Control Unit (ECU), reliability of these components is very important. To ensure safety and reliability, ISO 26262 standards are adapted which are derived from IEC 61508. This standard regulates the product development on system, hardware and software level and manages functional safety for electrical and electronic components. This paper discusses the applicability of the ISO 26262 standard to the development of EPAS ECU with respect to its hardware and software design. Hazard analysis and risk assessment of the basic EPAS architecture is performed and architecture is improved to achieve safety goal as per the standard.
2015-01-14
Technical Paper
2015-26-0085
Boris Belousov, Tatiana I. Ksenevich, Sergei Naumov
Abstract The modular designing principle is generally recognized in the automotive industry. However, the issue of building a wheel open-link locomotion module (OLLM) as a combination of steering (wheel turning), springing, traction drive and braking systems is not properly developed yet. An automated control system (ACS) is needed to able to unite and coordinate all the vehicle systems intended to manage the wheel. The automated control system intended to manage the steering and wheel springing parameters is a combination of an information and power channels, through which the wheel is electro-hydraulically driven, and the steering, springing and braking systems are controlled. The number of such channels in a wheeled mover of the vehicle or mobile robot is defined by the wheel type (driving, driven, steered or non-steered wheel). The plurality of such channels forms a complex of automated control systems of the wheeled mover.
2015-01-14
Technical Paper
2015-26-0078
Parth Lunia, Mrigendra Prajapati, V Jayashankar, Varun Parakh, Samir Rawte
Abstract This paper is an attempt to compile a systematic approach which can be easily incorporated in the product development system used in the design and development of parking brake systems for passenger cars having rear drum brakes, which in turn can effectively reduce the lead time and give improved performance. The vehicle GVW, percentage gradient and maximum effort limits (as per IS 11852 - Part 3), tire and drum brake specifications were taken as front loading. This data is used for target setting of functional and engineering parameters, such as lever pull effort, lever ratio and angular travel of lever. Design calculations were performed to obtain theoretical values of critical parameters like lever effort and travel. The comparison between target and theoretical values give the initial confidence to the system engineer. Further, the outcome was taken to conceptualize the hard points of lever on vehicle for ergonomics.
2015-01-14
Technical Paper
2015-26-0080
Wen Zhang, Bo Yang
Abstract Commercial vehicle plays an important role during transportation process under the demand of high speed, convenience and efficiency. So improving active safety of commercial vehicle has become a research topic. Due to the fact that braking characteristic is the basic and most closely related to safe driving of vehicle's performances, this paper aims to improve the braking performance by researching into an integrated control method based on the mature ABS products. Firstly, a strategy which gives priority to ABS and differential yaw moment control, complementary with the hydraulic active suspension control is proposed. In comparison with ABS, the combined control of brake system and suspension system is designed not only for preventing wheels lock. But the directional control to avoid roll or spin is more focused on. Then in order to run the novel method correctly, the controlled variables and evaluation criteria are illustrated briefly.
2015-01-14
Technical Paper
2015-26-0077
Deepak Sharma, Abhishek Atal, Abhay Shah
Abstract In this paper, design methodology of antiroll bar bush is discussed. Typical antiroll bar bushes have slide or slip mechanism, to facilitate the relative motion between ARB and bush. Inherently, this relative motion causes wear and noise of bush. To eliminate stated failure modes, the next generation bushes have been developed, which are using torsion properties instead of slip function. These bushes are already being used in various vehicles. This paper focuses on developing the simple mathematical model, design approach and optimization of ARB bushes. Also, comparison study is presented exploring, the differences and design criteria's between conventional and new generation anti-roll bar bushes.
2015-01-14
Technical Paper
2015-26-0079
Ram Ranjan Sahu, Jayant Sinha
Abstract Brake drum is an important component in automotive, which is a link between axle and wheel. It performance is of utmost importance as it is related to the safety of the car as well to the passengers. Many design parameters are taken into consideration while designing the brake drum. The sensitivity of these parameters is studied for optimum design of brake drum. The critical parameters in terms of reliability, safety & durability could be the cross section, thickness of hub, interference & surface roughness between bearing and hub, wheel loading, heat generation on drum, manufacturing and assembly process. The brake drum design is derived by considering these parameters. Hence the sensitivity of these parameters is studied both virtually & physically, in detail. The optimum value of each parameter could be chosen complying each other's values.
2015-01-14
Technical Paper
2015-26-0134
Jayant Sinha, Ajit Kharade, Shrihari Matsagar
Abstract An interior sound quality is one of the major performance attribute, as consumer envisage this as class and luxury of the vehicle. With increasing demand of quietness inside the cabin, car manufactures started focusing on noise refinement and source separation. This demand enforces hydraulic power steering pump to reduce noise like Moan and Whine, especially in silent gasoline engine. To meet these requirements, extensive testing and in-depth analysis of noise data is performed. Structured process is established to isolate noises and feasible solutions are provided considering following analysis. a) Overall airborne noise measurement at driver ear level (DEL) inside the cabin using vehicle interior microphone.b) Airborne and Pressure pulsation test by sweeping pump speed and pressure at test bench.c) Waterfall analysis of pump at hemi anechoic chamber for order tracking and noise determination.
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