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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
2015-01-2723
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
2015-01-2787
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
2015-01-2783
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
2015-01-2789
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
2015-01-2741
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
2015-01-2756
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
2015-01-2811
Tingjun Hu, Ho Teng, Xuwei Luo, Chun Lu, Jiankun Luo
When highly boosted, turbocharged gasoline direct injection (TGDI) engines can have torque curves comparable to those of light-duty (LD) diesel engines. Hence, applications of TGDI engines have been considered to be extended from passenger cars to LD vehicles, such as Ford F150 and E150. Most modern TGDI engines employ homogeneous mixture combustion with an injection pressure  150 bar typically. Under this combustion mode, two challenges having to be faced in the engine development are: 1) fuel dilution of the crankcase oil due to interactions of fuel sprays with the cylinder wall as a result of spray impingement on the cylinder wall or on the piston top when the fuel demand is high or fuel condensation during the warmup phase; 2) low-speed pre-ignition (LSPI) at high loads and low speeds, which often leads to a severe knock combustion known as the super knock. It is widely believed that LSPI is triggered by self ignition of oil particles entered the engine cylinder.
2015-09-29
Technical Paper
2015-01-2814
Rakhesh Bharathan
Simultaneous reduction of NOx and PM from engine exhaust of a diesel engine is an interesting area of research due to the implementation of stringent emission regulations all over the world. Cost involved in expensive after treatment systems such as DPF and SCR necessitate minimization of engine out pollutants. With minimum engine out emission achieved through engine hardware and combustion parameter optimization, possibility of elimination or downsizing of the after treatment system can be explored. The paper presents the effect of fuel injection parameters and EGR rate on exhaust emission of a boosted diesel engine. Effects of parameters such as rail pressure, pilot-post injections, SOI, EGR rate and EGR temperature on a 4 cylinder two valve direct injection diesel engine is studied. Present study reveals the possibility of elimination of after treatment systems at BS IV level with optimization of engine hardware and combustion parameters.
2015-09-29
Technical Paper
2015-01-2835
Sughosh J. Rao, M. Salaani, Devin Elsasser, Frank Barickman, Joshua L. Every, Dennis A. Guenther
This study was performed to showcase the possible applications of the Hardware in the Loop (HIL) simulation environment developed at The National Highway Traffic Safety Administration (NHTSA) Vehicle Research and Test Center (VRTC) research lab, to test heavy truck Electronic Stability Control (ESC) systems. In this study, the HIL simulation environment was used to recreate (an interpretation of) an actual accident scenario involving a single tractor-trailer. The scenario was then simulated with and without an ESC system to investigate the advantages afforded by the ESC system, if any. An acutal crash scenario reported in the Large Truck Crash Causation Survey (LTCCS), involving a single tractor-trailer was chosen. The crash scenario was interpretted as a path following problem and three possible driver intended paths were developed from the accident scene data. A path following algorithm was implemented in Simulink to simulate these paths.
2015-09-29
Technical Paper
2015-01-2846
Chunshan Li, Guoying Chen, Changfu Zong, Wenchao Liu
This paper presents a fault-tolerant control (FTC) algorithm for four-wheel independently driven and steered (4WID/4WIS) electric vehicles. The Unscented Kalman Filter (UKF) algorithm is utilized in the fault detection and diagnosis (FDD) module so as to estimate the in-wheel motor parameters, which could diagnose parameters variations caused by in-wheel motor fault. A sliding mode controller (SMC) is able to compute the generalized forces/moments to follow the desired vehicle motion. By considering the tire adhesive limits, a reconfigurable control allocator optimally distributes the generalized forces/moment among healthy actuators so as to minimize the tire workloads once the actuator fault is detected. An actuator controller calculates the driving torques of the in-wheel motors and steering angles of the wheels in order to finally achieve the distributed tire forces. If one or more in-wheel motors lose efficacy, the FDD module diagnoses the actuator failures first.
2015-09-29
Technical Paper
2015-01-2876
Shankar Patil, P Mahesh, Krishnan Sadagopan, Gokhul SA
In a tropical conditions , over a period of several months using 12 Nos. of New Generation 9-15T Intermediate Commercial Vehicles built with 4-Cyl 120HP BS3 Diesel engines run at regular interval from zero to 60000 Km. Field run data composed and analyzed with Intended Duty cycle for engine oil drain life estimation . The ICV trucks with sump capacity 0.083- 0.104 Liter/hp and SAE 15W40 viscosity of oil meeting API CH-4, API CI-4+ from group –I and Group-II base stocks are considered. The engine wear is more a function of silica concentration, load factor and age than the API category of oil. Oil drain interval is found proportional to the sump volume for the same stress on oil. Iron concentration and kinematic viscosity decide useful oil life with respect to the limits fixed by the engine manufacturer. In tropical conditions, field trials are carried out on 10T payload vehicles at higher temperature, humidity, dust levels and load factor than the other hemisphere conditions.
2015-09-29
Technical Paper
2015-01-2879
Evandro Silva
In recent years the commercial vehicle industry, specifically the heavy duty truck product line, has seen a rapid increase in the replacement of pure mechanical systems by electronic controlled systems. Engine, transmission, brakes, lighting, clusters, etc. are all monitored and/or controlled electronically. The adoption of electronic systems created a substantial change in the complexity of our products. Currently Diagnostic Trouble Codes (DTC) displayed on instrument clusters, in the majority of the cases, are no longer generated by a single sensor/component failure, instead these DTCs are triggered by a system monitor flag, result of a below average performance or a failure of an entire system. This new level of complexity makes it very difficult for the current diagnostic methods and tools, to identify what is causing the equipment to operate below ideal conditions.
2015-09-29
Technical Paper
2015-01-2895
Prasad Vegendla, Tanju Sofu, Rohit Saha, Mahesh Madurai Kumar, Long-Kung Hwang
This paper investigates the aerodynamic influence of multiple on-highway trucks in different platooning configurations. Complex pressure fields are generated on the highways due to interference of multiple vehicles. This pressure field causes an aerodynamic drag to be different than the aerodynamic drag of vehicle in no traffic condition. In order to study, the effect of platooning, three-dimensional modeling and numerical simulations are performed using STAR-CCM+® commercial Computational Fluid Dynamics (CFD) tool. The aerodynamic characteristics of vehicles are analyzed in five different platooning configurations with two and three vehicles in single and multiple lanes. A significant Yaw Averaged Aerodynamic Drag (YAD) reduction is observed in both leading and trailing vehicles. It is noted that YAD is based on the average result of three different yaw angles at 0, -6 and 6o. In single lane traffic, YAD reduction is up to 8% and 38% in leading and trailing vehicles, respectively.
2015-09-29
Technical Paper
2015-01-2897
Rick Mihelic, Jeff Smith, Matthew Ellis
Modern aerodynamic Class 8 freight tractors can improve vehicle freight efficiency and fuel economy versus older traditional style tractors when pulling Canadian style A- or B-Train double trailer long combination vehicles (LCV's) at highway speeds. This paper compares the aerodynamic performance of a current generation aerodynamic tractor with several freight hauling configurations through computational fluid dynamics evaluations using the Lattice-Boltzmann methodology. The configurations investigated include the tractor hauling a standard 53' trailer, a platooning configuration with a 30' separation distance, and an A-Train configuration including two 48' trailers connected with a dolly converter. The study demonstrates CFD's capability of evaluating extremely long vehicle combinations that might be difficult to accomplish in traditional wind tunnels due to size limitations.
2015-09-29
Technical Paper
2015-01-2860
Xinyu Ge, Jonathan Jackson
The application of Artificial Intelligence (AI) in automotive industry can dramatically reshape the industry. In past decades, many Original Equipment Manufacturers (OEMs) applied neural network and pattern recognition technologies to power train calibration, emission prediction and virtual sensor development. The AI application is mostly focused on reducing product development and validation cost. AI technologies in these applications demonstrate certain cost-saving benefits, but are far from disruptive effect. The disruptive impact can be realized when AI application finally bring cost-saving benefits directly to end users. For example, automation of vehicle or machine operation can dramatically improve the efficiency. However, there is still a gap between the current technologies and the one that can fully enable the vehicle or machine intelligence including reasoning, knowledge, planning and self-learning.
2015-09-29
Technical Paper
2015-01-2864
Xinyu Ge, Jarrett Corcoran, Paul Gamble
With stringent emission regulations, many subsystems that abate engine tailpipe-out emission become necessary part for engines. With the increased levels of complexity, end users also require increased level of quality for modern engines. Among the spectrum of quality control methodologies, one extreme example is focused on very components’ quality to ensure the accumulative deviation is within predetermined limits. These measures tighten the component tolerance during manufacturing process and typically results in increased cost. Another extreme example is on the other side of the methodologies spectrum. The methodology is to tailor the engine calibration solution to offset the manufacturing difference. Although the tailored engine calibration solution reduces manufacturing cost for components, it increases the calibration and validation cost for engines. Given the cost and time constraints, system integration plays an important role in engine development.
2015-09-29
Technical Paper
2015-01-2866
Saeil Jeon, Stacey Spencer, Paul Joiner
Lightweight solution is one of the keywords that we see every day. Developing smart, light and durable materials is one focal area that is inevitable to be done in the ground transportation sector. Another angle to look for is the protection and beautification of the substrate finish where surface treatment technology stands out. Combining both aspects is crucial in the industry for customer satisfaction. Recycled carbon fibers are used to form the reinforcement in the composite side, where they are infused or mixed with the matrix materials either in SMC (Sheet Mould Compound) or BMC (Bulk Mould Compound) format, depending upon the application. Glass fibers are usually used for the practical application, however considering further weight cut on the component, carbon fibers cannot be overlooked for their superior mechanical properties. However, due to the cost of carbon fibers many times the application may be over-designed.
Viewing 1 to 30 of 105101