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Viewing 1 to 30 of 105101
2015-11-01
Journal Article
2015-01-9074
Seung Yeon Yang, Nimal Naser, Suk Ho Chung, Junepyo Cha
Abstract Effects of temperature, pressure and global equivalence ratio on total ignition delay time in a constant volume spray combustion chamber were investigated for diesel fuel along with the primary reference fuels (PRFs) of n-heptane and iso-octane in relatively low temperature conditions to simulate unsteady spray ignition behavior. A KAUST Research ignition quality tester (KR-IQT) was utilized, which has a feature of varying temperature, pressure and equivalence ratio using a variable displacement fuel pump. A gradient method was adopted in determining the start of ignition in order to compensate pressure increase induced by low temperature heat release. Comparison of this method with other existing methods was discussed. Ignition delay times were measured at various equivalence ratios (0.5-1.7) with the temperatures of initial charge air in the range from 698 to 860 K and the pressures in the range of 1.5 to 2.1 MPa, pertinent to low temperature combustion (LTC) conditions.
2015-09-29
Technical Paper
2015-01-2849
Hariharan Venkitachalam, Axel schlosser, Johannes Richenhagen, Mirco Küpper PhD, Thomas Tasky
Electrification is a key enabler to reduce emissions levels and noise in commercial vehicles. With electrification, Batteries are being used in commercial hybrid vehicles like city buses and trucks for kinetic energy recovery, boosting and electric driving. A battery management system monitors and controls multiple components of a battery system like cells, relays, sensors, actuators and high voltage loads to optimize the performance of a battery system. This paper deals with the development of modular control architecture for battery management systems in commercial vehicles. The key technical challenges for software development in commercial vehicles are growing complexity, rising number of functional requirements, safety, variant diversity, software quality requirements and reduced development costs. Software architecture is critical to handle some of these challenges early in the development process.
2015-09-29
Technical Paper
2015-01-2883
Abhishek Shah
Electrical vehicle batteries are charge at 230 volt AC supply trough Vehicle charger. This vehicle charger and vehicle body are connected to Earth. So customer will not get shock in case of electric leakage current or vehicle body short to 230 volt Ac supply. But what if the house earthing fails or becomes ineffective, customer will get shock when he touches the vehicle body by standing the vehicle. Because the shock current will flow from the costumer body and takes return path from distribution transformer earthing. The House earthing are not always effective thus there are chances of getting shock. This can be prevented by adopting deferential protection in vehicle.CT Sense , current transform, can be use which will give current input give to controller and controller will compare the IN and OUT current from vehicle charging unit. In fault condition IN and OUT current are not equal thus controller unit will shut off the charging and will show “Shock warning” text on Driver display.
2015-09-29
Technical Paper
2015-01-2882
Abhishek Shah, Sanjay Phegade
Today the entire world is facing many serious problems namely population explosion, pollution and increasing fuel Prices. Increasing fuel prices is due to the depletion of non-renewable sources of energy, which will adversely affect automotive industry in very near future. Thus it's our responsibility to optimize vehicle fuel economy as much as possible and reduce the CO2 released by the vehicle. This paper focuses on optimizing the electrical energy consumption of vehicle. By introduction three concepts. 1) Innovative speed control logic for radiator & condenser fan motor according to air flow through radiator. 2) Introducing regeneration of energy from radiator and condenser fan motor while free running and deceleration of vehicle. 3) Using AC asynchronous motors (generation and motoring action) in radiator, condenser and blower motors.
2015-09-29
Technical Paper
2015-01-2723
Yaning Han, Hongyu Zheng, Ying Wan, Changfu Zong
Electro-hydraulic power steering system (EHPS) maintains the advantages of Hydraulic power steering system (HPS) and Electric power steering system (EPS).It is even more superior than this two. In the foreseeable future, this system will have a certain development space. Assistant characters analysis was carried out in this paper. Control strategy based on steering states and feedback control strategy were designed too. Besides, aiming at the emergency steering conditions, steering angular velocity additional controlling strategy was brought out. Under emergency steering conditions , steering angular velocity additional controlling strategy will be applied. Additional steering moment will be calculated to ensure the assistant follow steering rapidly.
2015-09-29
Technical Paper
2015-01-2730
Prasad S. Warwandkar, Naveen Sukumar, Preeti Gupta
Ever increasing operational cost, reducing profit margins & increase in competition, it is of upmost significance for fleet owners & drivers to opt for a vehicle having maximum up time. OEM's are under immense pressure to design & develop vehicles/subsystems which are reliable enough to minimize downtime & withstand heavy overloading plus extreme operating conditions especially tippers. Vehicle systems like Wheel end (hub, bearing, and grease) which are designed & packaged according to a very stringent envelop & operate as a closed system facing all the extremities of operating conditions. This undoubetly make them prone to no. of failure modes which are resulting in vehicle unplanned stoppages, so any failure mode related to the same must be taken care with utmost importance. In commercial vehicles the bearing outer cup is in interference fit with the hub. These bearings of wheel hub have to be maintained at the wheel end play of few microns.
2015-09-29
Technical Paper
2015-01-2732
Andrei Keller, Sergei Aliukov
The main indicators for mobility of a multipurpose wheeled vehicle are the maximum and average technical velocity, and they are mainly determined by power-to-weight ratio and the parameters of the suspension. As our analysis shows, with the increase of the power-to-weight ratio of the vehicle and its weight, the growth rate of the velocity is reduced, and after reaching a certain value, the velocity remains almost constant. This is due to the fact that for operating conditions of the multi-purpose wheeled vehicle, movement on roads with different degrees of uneven distribution of the rolling resistance and adhesion, in both transverse and longitudinal directions, is typical. In this investigation we evaluate the effectiveness of the main methods of power distribution between the drive wheels of the multi-purpose wheeled vehicles: disabling of drive axles, blocking of cross-axle and inter-axle differentials, a slowdown of slipping wheels.
2015-09-29
Technical Paper
2015-01-2747
Daniel E. Williams, Amine Nhila
With the expectation that means of redundant steering will be necessary for highly autonomous vehicles, different methods of providing redundant steering wheel be considered. One potential for redundancy is to steer the rear axle for directional control of the vehicle in the event of a failure in the primary steered front axle. This paper will characterize the dynamics of directional control of a three-axle vehicle when steered at the rear, and compare it to a conventionally steered three-axle vehicle.
2015-09-29
Technical Paper
2015-01-2787
Vladimir V. Vantsevich, Dennis R. Murphy
A distinctive feature of multi-wheel terrain vehicles is that the driveline system, which connects the drive wheels, influences the power losses in the tire-terrain interactions (power loss for tire slippage). The tire slippage power loss varies depending on characteristics of the driveline’s power-dividing units (PDUs) that split power between the drive axles and left and right wheels of each axle. This paper starts with an analysis of design configurations of the drivelines/PDUs of main dump truck manufacturing companies. It is shown that the trucks’ driveline systems are designed to pass through extreme terrain conditions and thus to provide superior terrain mobility. However, as it follows from the analysis, improvements of articulated truck energy efficiency and reduction of fuel efficiency by optimizing the power distribution to the drive wheels are still open issues.
2015-09-29
Technical Paper
2015-01-2788
Andrei Keller, Sergei Aliukov
In the present paper, it has been done study of different methods of power distribution among the drive wheels of an all-wheel-drive truck, namely: method of periodical action; method of partial solution; method of limit of excessive action; and method of introducing a rigid kinematic connection. Assessment how these methods influence on the performance characteristics of a multi-purpose vehicle has been done. For implementation of the method of periodical action the appropriateness of switching off some of the driving axles is justified. For implementation of the method of partial solution it is developed method of measuring of rational gear ratio of center differential providing the required level of performance of the all-wheel drive truck.
2015-09-29
Technical Paper
2015-01-2783
Renjith S, Vinod Kumar Srinivasa, Biswadip Shome
In an automotive power train system, the differential gear system plays a vital role of enabling the vehicle to transfer the engine torque to the wheels. The differential system consists of complex system of gears which are meshed with each other. Effective lubrication of the differential system ensures that the metal to metal contact between the gears is avoided. In addition, the lubricants also acts as thermal medium to effectively dissipate the heat produced due to frictional resistances. For dipped lubrication system, the use of lubrication oil leads to a loss of transmission power, and the loss increases with increasing rotational speeds and oil levels. Prediction and an understanding of the transmission loss inside the differential system is important as it provides a means to increase the power transmission efficiency. In addition, it provides insights to optimize the lubrication methods, gear profile, and gear housings.
2015-09-29
Technical Paper
2015-01-2792
Olof Erlandsson, Thomas Skare, Arnaud Contet
The automotive industry have become more and more interesting in recovering waste heat from internal combustion engines (ICE) , especially with future, tighter fuel and CO2 emission regulations in sight. Potential systems that recover waste heats have in all in common that they have lower efficiency than the ICE itself (otherwise the use of ICE would be questioned), hence the recovery system also need to expel a lot of waste heat to the surrounding. In this study we consider a simple automotive Rankine waste heat recovery system (WHRS) on a long-haulage truck that transform some of the ICE waste heat into useful energy but it still needs to return remaining heat to the surrounding, either through a direct condenser (CDS) or from an indirect CDS via a Low temperature radiator (LTR) to the surrounding, and this in the regular cooling module of the vehicle.
2015-09-29
Technical Paper
2015-01-2791
Srinivas Anantharaman, Manoj B
Nozzles tip Temperature (NTT) of an injector is a critical parameter for an engine as far as reliability of engine is concerned. It is required to ensure that the injectors operate under its operational limit because higher operating temperatures would result in enlargement of the nozzle spray tip, resulting in higher through flow, producing more undesirable power. This could result in failure of other components in the engine. In this paper we identify the various parameters that are critical for NTT and thereby predict the NTT by having the known input parameters. Response surface methodology and artificial neural network are used to identify the parameters, estimate the significance of each parameter and predict the NTT. Based on this analysis, even without the use of an instrumented injector NTT can be predicted at various working conditions of the vehicle on different terrains.
2015-09-29
Technical Paper
2015-01-2837
Premananth S, Dharmar Ganesh
Overall in-vehicle visibility is considered as a key safety parameter essentially mandated due to the increasing traffic scenario as seen in developing countries. Driver side bottom corner visibility is one such parameter primarily defined by A-pillar bottom and outside rear-view mirror (OSRVM). While defining the OSRVM package requirements such as size, position and regulatory aspects, it is also vital to consider other influencing parameters such as position of pillars, waist-line height, and Instrument panel which affects the in-vehicle visibility. This study explains the various package considerations, how an OSRVM housing can be optimized in order to maximize the in-vehicle visibility considering the road and traffic conditions. A detailed study on in-vehicle visibility impacted by OSRVM packaging explained and had been verified for the results.
2015-09-29
Technical Paper
2015-01-2891
The passive flow control using Jet Boat Tail is applied to a generic truck model to investigate the drag reduction effect. Wind tunnel testing is conducted with a CFD simulation using Large Eddy Simulation(LES). The truck model has the dimension of 220mmx200mmx150mm in the length, height and width direction respectively. The test speed is 30m/s. The wake flow field is measured in wind tunnel by 3D stereo Particle Image Velocimetry. The model is tripped to trigger the fully turbulent boundary layer. The wake width and depth is substantially reduced and indicates a significant drag reduction. The LES resolves the unsteady transient flow field with vortex shedding and coherent vortex structure. The jet boat tail shows an effect of suction of the boundary layer at the end of the truck model and it substantially thinners the boundary layer. The LES shows a drag reduction of 13% up to the realistic truck Reynolds number.
2015-09-29
Technical Paper
2015-01-2789
Igor Taratorkin, Alexander Taratorkin, Viktor Derzhanskii
The durability of hydromechanical transmissions of l wheeled chasses (WC), which operate in rugged environment, is limited due to part failure between the engine and the torque converter impeller. In the design under consideration, backlash opening in gears forms the highly nonlinear system and subharmonic resonances, which are not eliminated by existing methods. The research objective is to define methods of reducing hydromechanical transmissions (HMT) dynamic loading of WC, to develop and implement conventional designs providing tuning out of subharmonic resonant oscillations. On the basis of the developed mathematical model the dynamics of the highly nonlinear system is investigated, consistent patterns of resonant mode occurrences are established, which is experimentally confirmed.
2015-09-29
Technical Paper
2015-01-2762
Chunshan Li, Pan Song, Guoying Chen, Changfu Zong, Wenchao Liu
This paper presents an integrated chassis controller with multiple hierarchical layers for 4WID/4WIS electric vehicles. The proposed systematic design consists of the following four parts: 1) a reference model is in the driver control layer, which maps the relationship between the driver’s inputs and the desired vehicle motion. 2) a sliding mode controller is in the vehicle motion control layer, whose objective is to keep the vehicle following the desired motion commands generated in the driver control layer. 3) By considering the tire adhesive limits, a tire force allocator is in the allocation layer, which optimally distributes the generalized forces/moment to the four wheels so as to minimize the tire workloads during normal driving. 4) an actuator controller is in the executive layer, which calculates the driving torques of the in-wheel motors and steering angles of the four wheels in order to finally achieve the distributed tire forces.
2015-09-29
Technical Paper
2015-01-2763
S F RAHAMAN, Somenath Chatterjee
Steering pull during high speed braking of heavy commercial vehicles possesses a potential danger to the occupants. Even with negligible wheel-to-wheel brake torque variation, steering pull during the high speed braking has been observed. If the steering pull (i.e. steering rotation) is forcibly held at zero degree during high speed braking, the phenomena called axle twist, wheel turn and shock absorber deflection arise. In this work the data have been collected on the mentioned measures with an intention to develop a mathematical model which uses real time data, coming from feedback mechanism to predict the values of the measures in coming moments in order to aid steering system to ‘auto-correct’. Driven by the intention, ‘Time Series Analysis’, a well-known statistical methodology, has been explored to see how suitable it is in building the kind of model.
2015-09-29
Technical Paper
2015-01-2724
Peiwen Mi, Guoying Chen
Electric Power Steering System (EPS)can directly provide auxiliary steering torque via a motor. The extra motor and the reducer in mechanical system will make the friction torque in steering system larger, as a result, the ability of steering returning will be reduced. Therefore, during the design of EPS system control strategy ,an extra active return-to-middle control strategy is needed. For the fact that most of the low-end vehicles equipped with EPS system do not have a steering wheel angle sensor, a control strategy has to work without the datum of steering wheel angle. This paper proposes an active return-to-middle control method without steering wheel angle sensor, based on the estimated aligning torque which is converted to the pinion , and expounds how to determine the steering system current motion state in detail. This control method will work just during the turning condition, so it has no effect on the EPS basic assist characteristics.
2015-09-29
Technical Paper
2015-01-2833
Ashley L. Dunn, Brian Boggess, Nicholas Eiselstein, Michael Dorohoff, Harold Ralston
Brake chamber construction allows for a finite stroke for pushrods during brake application. As such, the Federal Motor Carrier Safety Regulations (FMCSRs) mandate maximum allowable strokes for the various chamber types and sizing. Brake strokes are often measured during compliance inspections and post-accident investigations in order to assess vehicle braking performance and/or capability. A number of forensic studies have been performed, and their results published, regarding the effect of brake stroke on braking force and heavy truck stopping performance. All of the studies have relied on a brake supply pressure in the neighborhood of 100 pounds per square inch (psi). When brake strokes are measured in the field, following the Commercial Vehicle Safety Alliance (CVSA) procedure, the application pressure is prescribed to be maintained between 90 and 100 psi.
2015-09-29
Technical Paper
2015-01-2832
Keith Friedman, John Hutchinson, Khahn Bui, Matthew Stephens, Alyssa Schmidt
The incidence of fire in heavy trucks has been shown to be about ten times higher under crash conditions than occurs in passenger vehicles. Fuel tank protection testing defined in J703 was originally issued in 1954. Advanced virtual testing of current and alternative fuel tank designs and locations under example representative impact conditions is reported.
2015-09-29
Technical Paper
2015-01-2741
Yunbo Hou, Mehdi Ahmadian
The primary purpose of this paper is to evaluate the effect of load, trailer arrangement, and speed on the roll stability of commercial trucks in roundabouts that are commonly used in urban settings with increasing frequency. The special geometric layout of roundabouts can increase the risk of rollover in roundabouts in high-CG vehicles, even at low speeds. Relatively few in-depth studies have been conducted on rollover stability of commercial trucks in roundabouts. This study uses a commercially available software, TruckSim®, to perform simulations on four truck configurations, including a single unit truck, a WB-67 semi-truck, the combination of a tractor with double 28-ft trailers, and the combination of a tractor with double 40-ft trailers. A single-lane and multilane roundabout are modeled, both with a truck apron. Three travel movements through the roundabouts are considered, including right turn, through-movement, and left turn.
2015-09-29
Technical Paper
2015-01-2749
Yang chen, Mehdi Ahmadian, Andrew Peterson
This study provides a simulation evaluation of the effect of maintaining balanced airflow, both statically and dynamically, in heavy truck air suspensions on the vehicle roll stability and ride comfort. The model includes a multi-domain evaluation of the truck multibody dynamics combined with detailed pneumatic dynamics of drive-axle air suspensions. The analysis is performed based on a detailed model of the suspension's pneumatics, from the main reservoir to the airsprings, a new generation of air suspensions with two leveling valves and air hoses and fittings that are intended to increase the dynamic bandwidth of the pneumatic suspensions. The suspension pneumatics is designed such that it is able to better respond to road input and body motion in real time. Specifically, this study aims at better understanding the airflow dynamics and how it couples with the vehicle dynamics.
2015-09-29
Technical Paper
2015-01-2756
Basaran Ozmen, Mehmet Bakir, Murat Siktas, Dr. Serter Atamer, Dr. Roman Teutsch
Securing the desired durability of suspension components is one of the most important topics for the vehicle designers because these components undergo multiaxial variable amplitude loading in the vehicle. Leaf springs are essential for the suspension system of trucks and should be considered as a security relevant part in the product development phase. In order to guide the engineers in the design and testing department, a simulation method was developed as explained in the paper “Bakir, M., Siktas, M., and Atamer, S., "Comprehensive Durability Assessment of Leaf Springs with CAE Methods," SAE Technical Paper 2014-01-2297, 2014”. In this new study, the main aim is to present the validation of this newly developed CAE method for the durability of leaf springs depending on the results from testing and measurement in the rough road and test bench.
2015-09-29
Technical Paper
2015-01-2740
Yuming Yin, Subhash Rakheja, Jue Yang, P.-E. Boileau
The articulated frame steering (AFS) systems are widely implemented in the construction, forestry and mining vehicles to achieve enhanced mobility and traction performance. Such vehicles generally consist of the front and rear units coupled by an articulation joint, while the steering is provided by the frame mounted left and right hydraulic steering struts. Compared to the conventional front wheel steer vehicles, the AFS generally yields considerably lower side-slip angles of the front tires during steering and thereby the better traction performance especially when operating on the rough terrains. The kinematic and dynamic performances of articulated steered vehicles (ASV) are strongly influenced by the properties of the AFS system. The articulation joint introduces additional yaw and/or roll degrees-of-freedom of the ASVs, which may lead to reduced roll stability limits and yaw divergence.
2015-09-29
Technical Paper
2015-01-2773
Lijuan Wang, Kenneth Kelly, Kevin Walkowicz, Adam Duran
The National Renewable Energy Lab’s (NREL) Fleet Test and Evaluations team recently conducted a 13-month technology evaluation of class 8 hybrid electric and conventional delivery trucks in the Coca-Cola fleet in Miami, Florida. Data from this fleet evaluation included on-road duty cycle as well as chassis dynamometer test data. A quantitative study was conducted by analyzing the impacts of various factors on fuel consumption (FC) by modeling and simulating a regional delivery truck using NREL’s Future Automotive Systems Technology Simulator (FASTSim). Factors used in this study included vehicle weight, hybridization and coefficient of rolling resistance and aerodynamic drag. The vehicle was simulated over real world drive cycles. The simulation results indicated that FC were approximately linear functions of the weight, coefficient of aerodynamic drag and rolling resistance over the real world drive cycles.
2015-09-29
Technical Paper
2015-01-2847
Adam Kouba, Jiri Navratil, Bohumil Hnilicka, Patrick C. Niven
Internal combustion engines continue grow more complex every day out of necessity. Legislation and increasing customer demand means that advanced technologies like multi-path EGR, advanced boosting, and aftertreatment systems continue to drive ever-expanding requirements for engine control to improve performance, fuel economy, and reduce emissions. Therefore, controller development and implementation are becoming more costly, both in terms of time and the monetary investment in engine hardware. To help reduce these costs, a sophisticated tool chain has been created which allows a real-time, physical, crank-angle resolved 1D engine model to be implemented on a rapid prototyping ECU which is then used in the control strategy of a running engine. Model-based controllers have been developed and validated to perform as well as or better than controllers using traditional sensors.
2015-09-29
Technical Paper
2015-01-2748
Salem A. Haggag
The vehicle dynamics and controls play a significant role for vehicle handling performance characteristics. The control of vehicle braking system and wheel slip is a challenging problem due to the nonlinear dynamics of the braking process and the wheel-road interaction. A simple and in the same time realistic vehicle longitudinal braking model is essential for such challenging problem. In this paper, a new longitudinal rolling/braking quarter-vehicle model is presented. The proposed model take both the rolling resistance force and the braking force in consideration and investigates their impact on the vehicle longitudinal dynamics. An anti-lock sliding-mode controller is designed to provide wheel slip control during vehicle motion. This type of controller is chosen due to its expected robustness against varying road friction coefficient.
2015-09-29
Technical Paper
2015-01-2750
Tan Huang, Guoying Chen, Changfu Zong, Tong Zhou
Electronically controlled air suspension (ECAS) has many advantages over leaf spring suspension in ride comfort and handling stability, it can also reduce the damage of road. Therefore ECAS is being widely applied to commercial vehicles. Through charging and discharging of the air springs, ECAS can adjust the characteristics of suspension system and the height of vehicle's body according to the vehicle's driving conditions, so as to improve the performance of commercial vehicle. However due to the complexity of charging and discharging process of ECAS, the phenomenon of "over-charging", "over-discharging" and oscillation can be occurred during the process of height adjustment, so the research on the control of height adjustment is very important.
2015-09-29
Technical Paper
2015-01-2795
Jayesh Mutyal, Sourabh Shrivastava, Rana Faltsi, Markus Braun
Stringent diesel emissions standards forcing a constant reduction in discharges of particulate matter and nitrogen oxide (NOx). Current state-of-the-art in-cylinder solutions are falling short of achieving these limits. Engine manufacturers are looking at different ways to meet the emission norms. Selective catalytic reduction (SCR) of oxides of nitrogen with ammonia gas is emerging as preferred technology for meeting stringent NOx emission standards across the world. SCR system designers face several technical challenges, such as avoiding ammonia slip, urea crystallization, low temperature deposits and other potential pitfalls. Simulation can help to develop a deep understanding of these technical challenges and issues, identify root causes and help develop better designs to overcome them. This paper describes the modeling approach for Urea-Water-Solution spray and its interaction with canister walls and exhaust gases.
Viewing 1 to 30 of 105101