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Viewing 1 to 30 of 105121
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
2015-01-2853
Enrique Busquets, Monika Ivantysynova
Over the last decade, a number of hybrid architectures have been proposed with the main goal of minimizing energy consumption of off-highway vehicles. One of the architecture subsets which has progressively gained attention is hydraulic hybrids for earth-moving equipment. Among these architectures, hydraulic hybrids with secondary-controlled drives have proven to be a reliable, implementable, and highly efficient alternative with the potential for up to 50% engine downsizing when applied to excavator truck-loading cycles. Multi-input multi-output (MIMO) robust linear control strategies have been developed by the authors’ group with notorious improvements on the control of the state of charge of the high pressure accumulator. Nonetheless, the challenge remains to improve the actuator position and velocity tracking.
2015-09-29
Technical Paper
2015-01-2852
Daniel Ribeiro, Rodrigo Chaves, Gian Marques, Rogerio Curty Dias
In order to evaluate the opportunities to use hybrid concepts for heavy commercial vehicles for emerging markets, MAN Latin America has developed a VW refuse truck with 23t GVW using the hybrid hydraulic technology. In site vehicle tests measurements has indicated a fuel savings up to 25%, which means a reduction around 4.08 liters of diesel/hour or 20 tones CO2/year . Thus, a collaborative cooperation with Rio de Janeiro Sanitation Department (Comlurb) was set for a truck evaluation on a real operation. This 03-month evaluation used one VW 17.280 6x2 hybrid hydraulic refuse truck and other VW refuse truck similar standard diesel. A random dispatch system ensures the vehicles are used in a similar manner. Global positioning system logging, fueling, and maintenance records are used to evaluate the performance of this hybrid hydraulic refuse truck.
2015-09-29
Technical Paper
2015-01-2855
Massimiliano Ruggeri, Giorgio massarotti, pietro marani, Carlo Ferraresi
In recent years many studies were performed with the aim of reducing losses and to optimize the oil flow management in complex machines like excavators. One of the most promising ideas is the pump switch, due to the flexibility of switching one or more pumps to serve one actuator, as a function of oil flow request and machine mode. These studies were basically developed in MAHA fluid power center in US and are based on a distribution manifold were hydrostatic transmissions are applied to the different loads. The system presented couples more actuators to every single pumps and offers also cross connections, in order to increase systems flexibility in flow management.
2015-09-29
Technical Paper
2015-01-2854
Timothy Opperwall, Andrea Vacca
Hydraulic systems have an important role in both on and off-highway vehicles. Designing for improved noise performance of fluid power systems is an essential part of improving current systems and opening up new areas where fluid power can bring improvements in efficiency and performance. As the technology advances and spreads to lighter applications, the noise generation and propagation due to hydraulic components becomes a primary design concern. The present research includes development of acoustic radiation models for noise radiation from hydraulic pumps and motors. The need for new methods for identification of noise sources and transmission is evident in order to direct future modeling efforts. Discovering the key features of noise generation from both simulation and experimental techniques allows for improved techniques to improve the noise performance of fluid power components and systems.
2015-09-29
Technical Paper
2015-01-2857
Paul K. Kalbfleisch, Monika Ivantysynova
Axial piston machines are widely used in many industries for their designs compactness, flexibility in power transfer, variable flow rate, and high efficiencies as compared to their manufacturing costs. One important component of all axial piston machines that is a very influential on the performance of the unit is the valve plate. The aim of this research is to develop a design methodology that is general enough to design all types of valve plates and the simple enough not to require advanced technical knowledge from the user. A new style of valve plate designs has been developed that comprehensively considers all previous design techniques and does not require significant changes to the manufacturing processes of valve plates. The design methodology utilizes a previously developed accurate computer model of the physical phenomenon. This allows the precise optimization of the valve plate design through the use of simulations rather than expensive trial and error processes.
2015-09-29
Technical Paper
2015-01-2856
Hongbin Wang, QingHui Yuan, Aaron Hertzel Jagoda
Fuel economy of both highway and off-highway vehicles is a major driver for new technology development. One of the technologies to meet this driver is a digital valve based hydraulic system. Digital valves are high speed on/off valves which are, in this case, using a pulse width modulated duty cycle to control flow. This enables flow control to multiple actuators at varying pressures without the losses associated with conventional throttling based flow control. By sequentially actuating the valves the pump is only connected to one load at any given time, this allows flow sharing from a common fluid power source, such as a pump, to multiple services without utilizing compensators or other metering devices. This also enables advanced control of the flow supplied to a given actuator and allows a different control strategy for each actuator. There is the potential to increase machine productivity through more efficient use of the installed engine power.
2015-09-29
Technical Paper
2015-01-2874
Marius-Dorin Surcel, Adime Kofi Bonsi
Lift axles increase the load capacity of a vehicle, allowing it to carry the extra load without the need for multiple vehicles, hence reducing operational costs. Furthermore, additional axles help to distribute the truck’s load across the road surface, reducing the chances of damage to the infrastructure. Lift axles can be raised when the vehicle has lighter load to save fuel and reduce wear and tear to the tires and axles. They can be deployed to improve traction especially in icy off-road applications. The main objective of this project was to assess the fuel-saving potential of lifting axles on unloaded semi-trailers. Part of the mandate was to identify and analyze regulations of various jurisdictions with respect to lift/loadable axles and studies leading to the setting up of these regulations. The SAE Fuel Consumption Test Procedures Type II (J1321) was used for fuel consumption track test evaluations.
2015-09-29
Technical Paper
2015-01-2875
Olof Lindgarde, Lei Feng, Anders Tenstam, Mikael Soderman PhD
CONVENIENT is a project where prediction and integrated control are applied on several subsystems with electrified actuators. A primary project goal is to develop a model-based optimal controller that uses predictive information in order to minimize fuel consumption. Another goal is to develop a control structure that both supports optimality and modularity since there is a need of adapting the controller to various truck configurations. A high-level controller denoted “Predictive Energy Buffer Control” controls several energy buffers in an integrated and optimal way using model predictive control. Several buffers are considered, such as the cooling system, the battery, and the vehicle kinetic energy. Controlling the vehicle kinetic energy means that when in cruise control mode the vehicle speed is varied with respect to the set speed in a fuel efficient way. Another focus is the communication between the driver and the control system.
2015-09-29
Technical Paper
2015-01-2881
Dhruv Gupta, Vasu Kumar
The danger posed by climate change and the striving for security of energy supply are issues high on the political agenda these days. Governments are putting strategic plans in motion to decrease primary energy use, take carbon out of fuels and facilitate modal shifts. Man’s energy requirements are touching astronomical heights. The natural resources of the Earth can no longer cope with it as their rate of consumption far outruns their rate of regeneration. The automotive sector is without a doubt a chief contributor to this mayhem as fossil fuel resources are fast depleting. The harmful emissions from vehicles using these fuels are destroying our forests and contaminating our water bodies and even the air that we breathe. The need of the hour is to look not only for new alternative energy resources but also clean energy resources. Hydrogen is expected to be one of the most important fuels in the near future to meet the stringent emission norms.
2015-09-29
Technical Paper
2015-01-2880
Fabio Luz Almeida, Philip Zoldak, Marcos Pimenta, Pedro Lacava
The use of numerical simulations in the development processes of engineering products has been more frequent, since it enables us to predict premature failures and to study new promising and valuable concepts. In industry, numerical simulation usually has the function of reducing the necessary number of validation tests before spending huge amount of resources on alternatives with less chance to succeed. In the context of an economically committed country, the matter of cargo transportation is of great importance, since it affects the trading of consumer goods between cities, states and their flow towards exportation. Thus, the internal combustion (ICE) Diesel cycle engines play an important role in Brazil, since they are extensively used in automotive applications and commercial cargo transportation, mainly due to their relevant advantage in fuel consumption and reliability.
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
2015-01-2894
Marius-Dorin Surcel, Mithun Shetty
The performance of several aerodynamic technologies and approaches, such as trailer skirts, trailer boat tails, gap deflectors and gap reduction, was evaluated using track testing, model wind tunnel testing, and CFD simulation, in order to assess the influence of the design, position and combination of various aerodynamic devices. Scale model wind tunnel tests were conducted to have the best direct performance comparisons between several possible configurations. The track test procedure followed the SAE J1321 SAE Fuel Consumption Test Procedure - Type II. The wind tunnel tests were conducted on a 1/8 scale model of a tractor in combination with a 53-foot semi-trailer. The tests consisted of two phases: setting the initial baseline, and component testing of various configurations.
2015-09-29
Technical Paper
2015-01-2892
Carlos A. Pereira, Max Morton, Claire Martin, Geert-Jan Schellekens
The current trend towards energy efficient commercial vehicles requires a substantial improvement in their aerodynamic performance. The two largest contributions to the drag of a tractor-trailer combination are the wake at the rear of the trailer and the turbulent in-flow at the trailer gap. By integrating into the design of the roof fairing ducts that divert and speed-up air flow it is possible to obtain a reduction of drag in the trailer gap and alter the trailer wake favorably. The resulting decrease in yaw-averaged overall drag coefficient is of 5.8%. This translates into an improvement in fuel efficiency of 3% when compared to the baseline . The design optimization was performed using parametric variation of a computational fluid dynamic model at zero and six degree yaw.
2015-09-29
Technical Paper
2015-01-2900
Jacques Ndione, Bradley Duncan
Recent regulations on greenhouse gas (GHG) emission standards for heavy-duty vehicles and high fuel prices have prompted government agencies to standardize procedures to assess aerodynamic performance of Class 8 tractor-trailers. The coastdown test procedure and scale model wind tunnel testing are the primary reference methods to assess vehicle drag. Other valid alternatives include constant speed testing and computational fluid dynamics (CFD) simulations. While there have been many published studies comparing results between simulations and wind tunnel testing, it is less well understood how to compare results with real-world aerodynamics. Both the wind tunnel and simulation directly measure aerodynamic drag forces in controlled conditions. In contrast, real-world testing is conducted in an open road environment in which aerodynamic forces are calculated from a road load equations, and variable wind and vehicle speed introduce additional complexity.
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
2015-01-2725
Amine Nhila, Daniel Williams
Over the years, steering systems have evolved from simple manual steering in the early car models to hydraulic power steering in the middle of the 20th century, and eventually to today’s systems where electric power steering is becoming more prevalent, specifically in light vehicles such as passenger cars. However, due to their relative low power density, electrical steering systems did not gain much traction in heavy vehicles, at least not as the sole source of power assistance. As a result of their higher power density, hydraulic power steering systems remain the main solution for steering heavy vehicles. Nonetheless, when these systems were first designed energy savings, and CO2 emissions were not a major concern while fuel prices were relatively low. Consequently, today’s state-of-the-art steering systems are not as efficient as they can be, and thus cause higher emissions.
2015-09-29
Technical Paper
2015-01-2726
Balaji Lomada, Rajakumar NG, Vijaykumar V
Commercial vehicles have steering system with one or more steering links (draglinks) connecting the steering gear box pitman arm and front axle steering arm. In case of twin steer vehicles, intermediate pivotal arm is used to transfer the motion proportionately between the two front axles. Intermediate pivotal arm is also used in some longer front over-hang vehicles to overcome their packaging constraints and to optimize the mechanical leverage. The pivot shaft is a mechanical part of the intermediate pivot arm assembly which is subjected to forces and bending moments generated by draglinks. In this work, study has been carried out on premature failure of the pivot shaft in city bus application model (Entry + 1 step). Metallurgical analysis of failed part indicated the failure to be due to fatigue. Pivot shaft was tested in rig with similar load conditions in order to replicate the failure. The failure mode and location of both, tested as well as field failure samples were identical.
2015-09-29
Technical Paper
2015-01-2727
Scott Lambert
The Global Brake Safety Council sees an increase in disc brake pads that are prematurely replaced before the end of the friction lining life cycle, due to: Rust related issues such as separation of friction lining from the disc brake shoe Fluctuation in critical dimensions A leading cause for both issues is the use of mill scale steel, or ‘black steel’ (non-pickled and oiled). In the North American aftermarket, as there are little or no steel specifications for disc brake shoes, black steel is increasingly used. GBSC conducted research of discarded disc brake pads from job-shops and engaged in discussions with metallurgists, major pad manufacturers and OE brake foundation engineers to identify root causes of premature pad replacement and the effects of black steel used for disc brake shoe manufacturing. Mill scale is embedded in and around the bond line of the friction lining and the disc brake shoe, causing a weaker bond, susceptible to rust jacking.
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
2015-01-2734
Anand Deshpande, Himanshu Gambhir, Kshitiz Raj, Satish kumar
Commercial vehicle manufacturers have been finding ways to economically and accurately optimize their vehicles long before the recent economic conditions presented themselves. There is need to focus on other vehicle aspects such as steering, ride comfort, braking and aesthetics in order to provide car like perception to truck, bus drivers and passengers during long distance drives. Steering System should provide precise movement with no play. In addition, the steering system should be smooth, compact and light. It needs to provide reasonably small turning radius so as to achieve good maneuverability and achieve good handling control as well as to minimize tire wear. Various reasons for high steering effort in right turn as compared to left turn have been presented in this paper. The basic reason for the above is inherent relationship in the linkages which causes this imbalance in steering effort.
2015-09-29
Technical Paper
2015-01-2737
Ata Donmez, Mahmut durus, Samet KIZILASLAN
In this study, the minimization of the pitching oscillation in the heavy trucks was aimed. The pitching oscillation, which disturbs the passengers, is defined as the moment about the lateral axis of the vehicles. Mainly, it is observed when a vehicle goes on rough road conditions. The main reason behind this problem is the time delay between the oscillations of the front and rear suspensions. Although there are a lot academic researches and papers about how pitching motion is minimized on the passenger vehicles, there are no certain specifications defined for heavy trucks. Since heavy truck axle loads are extremely changeable according to payload, correlations for the passenger cars are not applicable. To make certain specifications about heavy trucks, firstly the six degree of freedom mathematical model of the whole suspension system including tires, chassis suspension and cabin suspension of the truck was derived in the Matlab.
2015-09-29
Technical Paper
2015-01-2739
Sean Lopp, Eric Wood, Adam Duran
It has long been understood that road grade contributes to fuel use in commercial vehicles. With the recent availability of on-board data collection it is now possible to simulate fuel economy, incorporating road grade, and quantify this impact. This study uses real-world commercial drive cycles from the National Renewable Energy Laboratory’s (NREL) Fleet DNA database along with NREL’s Future Automotive Systems Technology Simulation Tool to evaluate the effects of road grade on fuel economy across a range of vocations, powertrains, operating conditions, and locations. Drive-cycles are matched with vocation specific vehicle models and simulated with and without grade. Fuel use due to grade is presented and variation due to drive cycle and vehicle characteristics is explored through graphical and statistical comparison. Aggregate results of this study suggest that road grade can contribute 1-9% of fuel use.
2015-09-29
Technical Paper
2015-01-2738
Ashraf Zeid
ABSTRACT Motor Graders (MG) are earth moving machinery used to grade and flatten the soil irregularities and for snow removal. The dynamic behavior of these machines is studied in this paper using full 6-degrees of freedom multibody dynamics as well as decoupled heave-pitch plane dynamics. MG models describing motions in the decoupled pitch-heave plane and in the yaw plane are developed from basic principles and from Bond Graph”, a standard graphical method for modeling of dynamic system. The Bond Graph is then algorithmically transformed into block diagram that is in turn coded in Simulink for time domain and frequency domain analysis. Bond Graph provides algorithmic development of the state space form of the models that is also coded in Matlab/Simulink for feedback controls design. A full 6-degree of freedom multibody system (MBS) dynamic model is also built using commercial available software ADAMS.
2015-09-29
Technical Paper
2015-01-2743
R Gautham Sajan, Manojkumar Ramasamy
The sale of vehicles in markets regulated by homologation standards requires that the vehicle pass all the tests mandated by the standard, for the vehicle to be sold in that market. The task of conducting homologation tests was based on the GOST Standard R52302-2004, for Handling and Stability assessment, for the Russian market. The handling and stability requirements for Gulf Countries as mandated by the Gulf standard GSO 42 can be satisfied, if the vehicle is able to pass the tests mandated by GOST R 52302. The Turn and Relocation test mandated by the standard required that the loss of tire contact with the ground be determined. This can be determined with effortless ease using wheel force transducers. Facility and equipment constraints made the testing procedure a costly affair. Instead, it was decided to develop a method in-house for determining tire contact loss. The first phase of the methodology involves the simulation of the tests using TruckSim® software.
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
2015-01-2744
Craig Birkett, Somnath Ghorad
Lateral loading developed by scrubbing of the rear tandem suspension during sharp turns is an important load case for frame durability in heavy duty vehicles. A study was done to understand the deflection of the frame under lateral loads and to correlate this with test data for a typical long haul Class 8 tractor. The results showed the contributions of frame bending, frame shear, and suspension yaw to overall lateral flexibility. This gives a better understanding of deflection modes which impact stress developed in frame components under this loading. It can also be useful for handling estimates.
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